Microfacies analysis and 3D reconstruction of bioturbated sediments in the calcarenite di Gravina formation (southern Italy) - Bonomo, Agnese Emanuela; Munnecke, Axel; Schulbert, Christian; Prosser, Giacomo (Marine and Petroleum Geology, 2021)
The Calcarenite di Gravina is a poorly lithified, heterogeneous bio-lithoclastic Plio-Pleistocene limestone formed in a temperate shallow-water setting. Since prehistoric times it has been used for construction, as witnessed by the “Sassi”, the old city center of Matera (southern Italy). Here, the relatively distal, fine-grained bioclastic grain-packstone is characterized by large bioturbation structures of crustaceans. The aim of this work is to understand how bioturbation controls texture, porosity, permeability, and the cementation of the calcarenite. Crustaceans such as Callianassa are known to produce vertical burrows and sort grains. A bioturbated calcarenite level, outcropping in the Parco Scultura- Cava Paradiso in La Palomba (Matera northern area), has been selected as case study. Large rock samples including fossil traces and surrounding rocks have been analysed. Optical microscope and SEM observations show a close connection between sediment sorting and cementation, and 3D analyses by means of CT scans indicate that the internal structure and the connected porosity of the samples is a function of the cementation. Moreover, the porosity network is reconstructed in 3D in order to derive the real connected porosity variations and their implications for the evolution in terms of diagenesis and alteration of the rocks. Indeed, a cementation gradient from the external lining of the burrows to the internal part of the trace fossil is observed. Cementation is less pronounced outside of the trace fossil. Cluster analysis of point-counting results allows to identify four sub-facies characterized by differences in composition, cementation and porosity. One of them is present in the interior of the burrows while the other two characterize the external lining (crust) and storage chamber of crustacean burrows. The last sub-facies occurs in the area surrounding the trace fossils and shows a weaker cementation. The presence of a cementation gradient inside the trace fossil is explained through a diagenetic model that considers the contribution of different factors. The geochemical environments allow the CaCO3 precipitation inside the burrows starting from the lining to the internal area thanks to the microbial actions, water circulation and relative oxygenation of fluids. Dissolution of aragonitic components probably represents the principal source of CaCO3. Variation in cementation and porosity are quite moderate, but capable of generating major differences in the resistance to weathering. From this study it emerges how the diagenetic processes lead to significant changes in the bioturbated fabric, making the burrows less permeable than the surrounding sediment. This is confirmed by the selective erosion that brings to light very well-preserved traces of Callianassidae even on building stones.
CRIS-Team Scopus Importer:2021-01-08
Keywords: 3D porosity; Bioturbation; Diagenesis; microCT-scan modelling

Microfacies and carbon isotope records of Mississippian carbonates from the isolated Bama Platform of Youjiang Basin, South China: Possible responses to climate-driven upwelling - Liu, Chao; Jarochowska, Emilia; Du, Yuansheng; Vachard, Daniel; Munnecke, Axel (Palaeogeography, Palaeoclimatology, Palaeoecology, 2015)
Changes in Mississippian global paleogeography derived from the reconfiguration of the continents have been suggested to result in a change in oceanic circulation, carbon cycling, as well as in global cooling. Here, integrated δC chemostratigraphy and foraminiferal biostratigraphy across the Mississippian (late Tournaisian, Visean, early Serpukhovian; MFZ6-MFZ16 foraminiferal biozones) of the Gongchuan section located in the isolated Bama Platform in the Youjiang Basin, South China, are presented. The δC trend shows an abrupt decline during late Visean (Asbian-early Brigantian; MFZ13-14). This decline is also observed in subequatorial western Euramerica, whereas coeval sections in subequatorial eastern Euramerica show consistently elevated δC values across the entire Visean. The δC decline in western Euramerica and the South China Block (eastern Paleo-Tethys) coincides with a global regression with a suggested glacioeustatic origin, the onset of high-frequency climate and sea-level oscillations, and the closure of the Rheic seaway between Euramerica and Gondwana. We propose a model explaining the divergence of δC records resulting from the closure of the Rheic seaway and development of upwelling zones in the western margin of Euramerica and the eastern Paleo-Tethys realm. Quantitative microfacies analysis across the Mississippian succession in the Gongchuan section shows facies-independent disappearance of corals and increased proportion of cortoids and filter-feeding organisms at the onset of the Asbian δC decline, which may support an increase in nutrient level that can be expected as a result of upwellin
Keywords: Euramerica; Foraminiferal zones; Late Paleozoic Ice Age; Paleo-Tethys; Point-counting; Visean

Microfacies, depositional environments and meter-scale cycles of the middle jurassic Tuwaiq Mountain formation, central Saudi Arabia - El-Yamani, Mahmoud Samir; Al-Ramadan, Khalid; Munnecke, Axel; Cantrell, Dave; Abdulghani, Waleed; Reub, Lukas (Journal of African Earth Sciences, 2018)

Microplastic contamination of the drilling bivalve Hiatella arctica in Arctic rhodolith beds - Teichert, Sebastian; Löder, Martin; Pyko, Ines Anna; Mordek, Marlene; Schulbert, Christian; Wisshak, Max; Laforsch, Christian (Scientific Reports, 2021)
There is an increasing number of studies reporting microplastic (MP) contamination in the Arctic environment. We analysed MP abundance in samples from a marine Arctic ecosystem that has not been investigated in this context and that features a high biodiversity: hollow rhodoliths gouged by the bivalve Hiatella arctica. This bivalve is a filter feeder that potentially accumulates MPs and may therefore reflect MP contamination of the rhodolith ecosystem at northern Svalbard. Our analyses revealed that 100% of the examined specimens were contaminated with MP, ranging between one and 184 MP particles per bivalve in samples from two water depths. Polymer composition and abundance differed strongly between both water depths: samples from 40 m water depth showed a generally higher concentration of MPs and were clearly dominated by polystyrene, samples from 27 m water depth were more balanced in composition, mainly consisting of polyethylene, polyethylene terephthalate, and polypropylene. Long-term consequences of MP contamination in the investigated bivalve species and for the rhodolith bed ecosystem are yet unclear. However, the uptake of MPs may potentially impact H. arctica and consequently its functioning as ecosystem engineers in Arctic rhodolith bed

Microplastic pollution as a possible threat for an arctic reef system and its association of ecosystem engineers - Pyko, Ines Anna; Löder, Martin; Schulbert, Christian; Wisshak, Max; Laforsch, Christian; Munnecke, Axel; Teichert, Sebastian (54th European Marine Biology Symposium, 2019)
The coralline red alga Lithothamnion glaciale forms rigid frameworks of magnesium calcite. The shelfs around the high arctic Svalbard archipelago (northern Norway) are intensely covered by these so-called rhodoliths. Drilled by boring mussels of the species Hiatella arctica , many rhodoliths become hollow ecospheres, inhabited by a great variety of benthic taxa. Thereby, these rhodolith communities can be regardedas arctic reef structures and increase the local biodiversity significantly, comparable to corals in the tropics. They also provide a possible nursery ground for fish. We report the first findings of microplastic ingested by individuals of H. arctica. Altogether, we identified eight different types of polymers via F-spectroscopy within the rhodolith-colonizing bivalves. The potential consequences for the bivalves can be manifold, including a negative impact on their function as an ecosystem-engineering organism. This would also affect the complete ecosystem of the Svalbard Shelf and its biodiversity.
Keywords: Arctic; biodiversity; ecosystem engineers; microplastic

Microproblematic organisms from the Norian-Rhaetian reefal carbonates of Saklikent, Taurus Mountains, southern Turkey - Senowbari-Daryan, Baba; Link, Michael (Facies, 2018)
UnivIS-Import:2018-09-05:Pub.2018.nat.dgeo.IGM.LP.microp

Microstructural evolution during initial stages of static recovery and recrystallization: New insights from in-situ heating experiments combined with electron backscatter diffraction analysis - Bestmann, Michel; et al. (Journal of Structural Geology, 2005)
Keywords: Electron backscatter diffraction; Grain boundary migration; In-situ heating; Microstructure; Rocksalt

Microstructure and fluid flow in the vicinity of basin bounding faults in rifts – The Dombjerg Fault, NE Greenland rift system - Salomon, Eric; Rotevatn, Atle; Kristensen, Thomas Berg; Grundvåg, Sten-Andreas; Henstra, Gijs Allard (Journal of Structural Geology, 2021)
Faults commonly form loci for high fluid flux in sedimentary basins, where fluids, rocks and deformation processes frequently interact. Here, we elucidate the interaction of fluid flow, diagenesis and deformation near basin-bounding faults in sedimentary basins through a study in the vicinity (0–3.5 km) of the Dombjerg Fault in the NE Greenland rift system. Due to fault-controlled fluid circulation, fault-proximal syn-rift clastics underwent pervasive calcite cementation, whereas uncemented clastics at some distance from the fault remained highly porous and friable. Correspondingly, two distinct deformation regimes developed to accommodate continued deformation: discrete brittle fractures formed in calcite cemented rocks, whereas cataclastic deformation bands formed in uncemented deposits. We show that low-permeable deformation bands forming in highly porous rocks were associated with localized host rock alteration, and chemical reduction of porosity along bands. In rocks with cementation-induced low porosity, brittle fractures created new pathways for fluids, but were subsequently filled with calcite. Occasionally, veins comprise multiple generations of microcrystalline calcite, likely precipitated from rapidly super-saturated fluids injected into the fractures. This suggests cemented deposits sealed uncemented compartments, where fluid overpressure developed. We conclude that compartmentalized flow regimes may form in fault-bounded basins, which has wide implications for assessments of potential carbon storage, hydrocarbon, groundwater, and geothermal sites.
CRIS-Team Scopus Importer:2021-10-29
Keywords: Syn-rift; Fluid flow; Fault evolution; Structural diagenesis; Fracturing; Cementation

Microstructures of modern sea pen axes – a tool for the systematics of fossil pennatulaceans (Octocorallia) - Roden, Vanessa; Reich, Mike (Terra Nostra 2012/3, 2012)

Middle Ordovician sea-level changes and the evolution of the Ordovician conodont genus Cahabagnathus Bergström, 1983. - Leslie, Stephen Andrew; Lehnert, Oliver (Journal of Paleontology, 2005)
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LG.middle

Middle to Late Ordovician carbon isotope chemostratigraphy of the Lower Yangtze Platform: Implications for global correlation - Gong, Fangyi; Joachimski, Michael; Yan, Guanzhou; Li, Lixia; Wei, Xin; Wu, Rongchang (Geological Journal, 2021)
Middle to Late Ordovician carbonates were collected in South China (Anhui Province) from the Kuniutan, Datianba, and Pagoda formations in the Dingxiang and Daling sections and analysed for high‐resolution carbon isotope chemostratigraphy. An increase by 0.4‰ in δ13Ccarb is observed in the upper part of the Kuniutan Formation (Eoplacognathus pseudoplanus Biozone), representing the rising limb of the Middle Darriwilian Isotopic Carbon Excursion (MDICE). In the upper part of the Datianba Formation, positive shifts of ca. 1‰ are recorded in the studied section which compare with the carbon shifts reported in North America and Baltoscandia. A pronounced positive δ13Ccarb excursion of ca. 1.5‰ from the lower part of the Pagoda Formation can be correlated with the global Guttenberg Isotopic Carbon Excursion (GICE). The documentation of three carbon isotope shifts in this study provides new evidence for changes in the global carbon cycle from Darriwilian to Early Katian which could have been influenced by changes in global climate and primary productivity.<br

Middle to Upper Jurassic bivalves of the southwestern Morondava Basin (Madagascar) - Fürsich, Franz; Ayoub-Hannaa, Wagih; Heinze, Michael (Zitteliana, 2019)

Mid-ocean ridge basalt generation along the slow-spreading, South Mid-Atlantic Ridge (5-11°S): Inferences from 238U- 230Th- 226Ra disequilibria - Turner, Simon P.; Kokfelt, Thomas; Hauff, Folkmar; Haase, Karsten; Lundstrom, Craig; Hoernle, Kaj; Yeo, Isabel; Devey, Colin (Geochimica Et Cosmochimica Acta, 2015)
U-series disequilibria have provided important constraints on the physical processes of partial melting that produce basaltic magma beneath mid-ocean ridges. Here we present the first 238U-230Th-226Ra isotope data for a suite of 83 basalts sampled between 5°S and 11°S along the South Mid-Atlantic Ridge. This section of the ridge can be divided into 5 segments (A0-A4) and the depths to the ridge axis span much of the global range, varying from 1429 to 4514m. Previous work has also demonstrated that strong trace element and radiogenic isotope heterogeneity existed in the source regions of these basalts. Accordingly, this area provides an ideal location in which to investigate the effects of both inferred melt column length and recycled materials. 226Ra-230Th disequilibria indicate that the majority of the basalts are less than a few millennia old such that their 230Th values do not require any age correction. The U-Th isotope data span a significant range from secular equilibrium up to 32% 230Th excess, also similar to the global range, and vary from segment to segment. However, the (230Th/238U) ratios are not negatively correlated with axial depth and the samples with the largest 230Th excesses come from the deepest ridge segment (A1). Two sub-parallel and positively sloped arrays (for segments A0-2 and A3 and A4) between (230Th/238U) and Th/U ratios can be modelled in various ways as mixing between melts from peridotite and recycled mafic lithologies. Despite abundant evidence for source heterogeneity, there is no simple correlation between (230Th/238U) and radiogenic isotope ratios suggesting that at least some of the trace element and radiogenic isotope variability may have been imparted to the source regions > 350kyr prior to partial melting to produce the basalts. In our preferred model, the two (230Th/238U) versus Th/U arrays can be explained by mixing of melts from one or more recycled mafic lithologies with melts derived from chemically heterogeneous peridotite source regions.

Migration of Arc Magmatism Above Mantle Wedge Diapirs With Variable Sediment Contribution in the Aegean - Schaarschmidt, Anna; Haase, Karsten; Voudouris, Panagiotis C.; Melfos, Vasilios; Klemd, Reiner (Geochemistry Geophysics Geosystems, 2021)

Migration von Weichmachern und Beschichtungen während der extrakorporalen Perfusion in der Kardiotechnik - Münch, Frank; Göen, Thomas; Schulbert, Christian; Cesnjevar, Robert; Ihlenburg, Katharina Susanne (Abstracts der 40. Internationalen Jahrestagung der DGfK und 3. Fokustagung Herz, 2011)
UnivIS-Import:2017-12-18:Pub.2011.nat.dgeo.IGM.LP.migrat

Mineralization of autochthonous particulate organic carbon is a fast channelof organic matter turnover in Germany's largest drinking water reservoir - Dordoni, Marlene; Seewald, Michael; Rinke, Karsten; Friese, Kurt; van Geldern, Robert; Schmidmeier, Jakob; Barth, Johannes (Biogeosciences, 2022)
Turnover of organic matter (OM) is an essential ecological function in inland water bodies and relevant for water quality especially for the potential of dissolved organic carbon (DOC) removal as well as due to emissions of CO2. We investigated various sources of OM including DOC, autochthonous particulate organic carbon (allo-POC), allochthonous particulate organic carbon (allo-POC), and sedimentary matter (SED) in a temperate drinking water reservoir (Rappbode Reservoir, Germany) with respect to carbon isotope ratios and concentration dynamics. For this purpose, we focused on the metalimnion and the hypolimnion, where respiratory turnover is expected to be dominant and hardly disturbed by atmospheric exchange. The observation period of nine months covered a complete stratification period of the water body. Dissolved inorganic carbon (DIC) concentrations and its isotopes (delta C-13(DIC)) were considered together with isotope data of DOC and POC (delta C-13(DOC) and delta C-13(POC)) as input parameters for mass balances. DIC concentrations ranged between 0.30 and 0.53 mmol L-1 , while delta C-13(DIC) values were between -15.1 and -7.2 parts per thousand versus the VPDB (Vienna PeeDee Belemnite) standard. Values of delta(13)C(DOC )and delta C-13(auto-POC) ranged between -28.8 and -27.6 parts per thousand and between -35.2 and -26.8 parts per thousand, respectively. Isotope compositions of sedimentary material and allochthonous POC were inferred from the literature with average values of delta C-13(SED) = -30.7 parts per thousand, and delta C-13(allo-POC) = -31.8 parts per thousand. Comparison of DIC concentration gains and stable isotope mass balances showed that autochthonous POC from primary producers was the main contributor to DIC increases, while contributions from DOC, ExtPOC and SED played a minor role. OM turnover rates, i.e. the conversion of organic carbon towards DIC, calculated with our isotope approach were within the range for oligotrophic water bodies (0.01 to 1.3 mu mol L(-1 )d(-1)). Some higher values in the metalimnion are likely due the availability of settling POC from the photic zone. Samples from a Metalimnetic Oxygen Minimum (MOM) showed a clear dominance of respiration over photosynthesis through bacterial degradation of autochthonous POC. These high turnover rates further highlight a close link with planktonic biological assemblages. Our work shows that respiration in temperate lentic water bodies largely depends on autochthonous POC production as a major carbon source
CRIS-Team WoS Importer:2022-12-09

MINERALOGICAL, BIB-SEM AND PETROPHYSICAL DATA IN SEAL ROCK ANALYSIS: A CASE STUDY FROM THE VIENNA BASIN, AUSTRIA - Misch, D.; Siedl, W.; Drews, Michael; Liu, B.; Klaver, J.; Pupp, M.; Sachsenhofer, R. F. (Journal of Petroleum Geology, 2021)
The Vienna Basin is a major hydrocarbon province with a long exploration history. Within the basin, secondary migration from Upper Jurassic source rocks into stacked Middle Miocene (Badenian) sandstone reservoirs was formerly considered to have occurred almost entirely along major fault zones. However recent exploration data has suggested that in areas where no major faults are present, oil may have migrated vertically through the sandy mudstone intervals separating individual reservoir units, which are therefore imperfectly sealed. In order to investigate possible secondary migration through the semi-permeable mudstones, this study links variations in gross depositional environment (GDE) to variations in mudstone properties (e.g. mineralogy and pore size distribution). The study focussed on the mudstones which seal reservoir sandstones referred to locally as the “8.TH” and “16.TH” units. The bulk mineralogical composition of 56 mudstone and sandy mudstone (and minor intercalated muddy sandstone) samples from seal layers in 22 wells was studied by X-ray diffraction analysis, broad ion beam – scanning electron microscopy (BIB-SEM), mercury intrusion porosimetry (MICP) and N2 adsorption. These data are interpreted in the context of GDE maps of the Vienna Basin which were previously established using seismic and well log data. Results indicate that the gross depositional environment strongly controlled the pore space characteristics of the mudstones. The sandy mudstones in the NW part of the study area were influenced by a complex eastward-prograding deltaic system which deposited coarse detritus into a major palaeo depression (“Zistersdorf Depression”) located in the centre of the basin. Higher overall porosity and a dominance of larger pore size classes, probably resulting in reduced seal quality, were observed for sandy mudstones from well locations within feeder channels and also from within the Zistersdorf Depression. Similarly, sandy mudstones from locations associated with the long-term input of coarser sediments in shoreline, coastal and proximal offshore settings in the NW and central parts of the study area are considered to be of lower sealing quality compared to fine-grained mudstones deposited in distal, open-marine settings which prevailed in the SE part of the study area throughout the Middle Miocene. In general, pore geometries were influenced by mineralogical composition; quartz- and detrital carbonate-rich samples show equidimensional pores, while more elongated pores (with a higher average aspect ratio) characterize clay-rich samples. Furthermore, matrix mesopores (2-50 nm) determined by N2 sorption are more abundant in clay-rich versus quartz-rich samples, and show a pronounced positive trend with increasing percentage of illite-smectite mixed-layer clay minerals. This study shows that regional-scale mudstone seals in the Vienna Basin have been influenced by variations in sedimentation associated with lateral variations in gross depositional environment during the Middle Miocene. The observed pore characteristics will serve as input data for future models of secondary migration.
CRIS-Team Scopus Importer:2020-12-25
Keywords: Austria; BIB-SEM; cap rocks; gas adsorption; hydrocarbon migration; MICP; Miocene; sandstone reservoirs.; seal capacity; Vienna Basin

Mineralogical characteristics of Ettringites synthesized from solutions and suspensions - Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde; Schwesig, Peter (Cement and Concrete Research, 2006)
Due to the wide technical importance of Ettringite (3CaO•Al 2O3•3CaSO4•32H2O) in hydrated cement based systems, four different synthesis methods were applied to get a better overview on how and under what favoring conditions Ettringite can be formed. In the first step different precipitation methods resulting in Ettringite were established. For all methods Al3+ was supplied by aqueous CO2-free solution of Al2(SO4) 3•18H2O. As a source of CaO-supply a clear solution and otherwise a Ca(OH)2-suspension was utilized. Four synthesis routes with and without sucrose were employed. Variation of reaction parameter like temperature, time of reaction, pH-value of synthesis solution and influence of additional Gypsum were investigated. The qualitative phase analysis was performed by X-ray diffraction method (XRD). Morphological aspects of some synthesis products were studied by scanning electron microscopy (SEM). Finally lattice and structural parameter of the Ettringites were determined by refinement of XRD-pattern using the Rietveld-Method. © 2005 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2006.nat.dgeo.IGM.LM.minera
Keywords: Characterization; Ettringite; SEM; X-ray diffraction

Mineralogical characterization of calcium phosphate cements for clinical needs - Götz-Neunhoeffer, Friedlinde; Hurle, Katrin (Multiscale Cell-Biomaterials Interplay in Musculoskeletal Tissue Engineering and Regenerative Medicine, 2023)
Upon mixing of calcium phosphate cements (CPCs) with an aqueous liquid, the hydration starts. This dissolution–precipitation reaction is resulting in H2O-containing CaP phases. Mineralogical characterization of both processes can be easily performed by quantitative X-ray powder diffraction (XRD) analysis and heat-flow analysis. Rietveld refinement of XRD data is a very powerful tool for investigation of solid solutions in ion-doped CPCs and the time-dependent formation of apatite or brushite. G-factor allows quantification of the amorphous content, either of the anhydrous powder or in the hydrated pastes. For successful application of CPCs, properties of both paste and hardened cements must be carefully adjusted to meet clinical requirements. For proper application, injectability, cohesion, and setting time of the pastes are highly relevant. The hardened cement must allow proper degradation, which is related to both phase composition and porosity. Finally, the optimization of mechanical strength by polymeric additives needs to be monitored by the described setup of the methods.
CRIS-Team Scopus Importer:2024-12-16
Keywords: Analytical method; Calcium phosphate cement; Crystallinity; Crystallography; External standard method; Hydroxyapatite; Isothermal calorimetry; Mineralogy; Quantitative X-ray diffraction; Setting reaction

Mineralogical, compositional and isotope characterization of human kidney stones (urolithiasis) in a Sri Lankan population - Chandrajith, Rohana; Weerasingha, Anushka; Premaratne, Kusala M.; Gamage, Dhanushke; Abeygunasekera, Anuruddha M.; Joachimski, Michael; Senaratne, Atula (Environmental Geochemistry and Health, 2019)
Keywords: FTIR; Hydroxylapatite; Calcium oxalate monohydrate; Carbon isotopes; Trace elements; Urinary stones

Mineralogical constraints on the potassic and sodic-calcic hydrothermal alteration and vein-type mineralization of the maronia porphyry cu-mo ± re ± au deposit in NE greece - Melfos, Vasilios; Voudouris, Panagiotis; Melfou, Margarita; Sánchez, Matías G.; Papadopoulou, Lambrini; Filippidis, Anestis; Spry, Paul G.; Schaarschmidt, Anna; Klemd, Reiner; Haase, Karsten; Tarantola, Alexandre; Mavrogonatos, Constantinos (Minerals, 2020)
The Maronia Cu-Mo ± Re ± Au deposit is spatially related to a microgranite porphyry that intruded an Oligocene monzonite along the Mesozoic Circum-Rhodope belt in Thrace, NE Greece. The magmatic rocks and associated metallic mineralization show plastic and cataclastic features at the south-eastern margin of the deposit that implies emplacement at the ductile-brittle transition, adjacent to a shear zone at the footwall of the Maronia detachment fault. The conversion from ductile to brittle deformation caused a rapid upward magmatic fluid flow and increased the volume of water that interacted with the host rocks through high permeable zones, which produced extensive zones of potassic and sodic-calcic alteration. Potassic alteration is characterized by secondary biotite + K-feldspar (orthoclase) + magnetite + rutile + quartz ± apatite and commonly contains sulfides (pyrite, chalcopyrite, pyrrhotite). Sodic-calcic alteration consists of actinolite + sodic-calcic plagioclase (albite/oligoclase/andesine) + titanite + magnetite + chlorite + quartz ± calcite ± epidote-allanite. The high-oxidation state of the magmas and the hydrothermal fluid circulation were responsible for the metal and sulfur enrichments of the aqueous fluid phase, an increase in O2 gas content, the breakdown of the magmatic silicates and the production of the extensive potassic and sodic-calcic alterations. Brittle deformation also promoted the rapid upward fluid flow and caused interactions with the surrounding host rocks along the high temperature M-, EB-, A-and B-type veins.
CRIS-Team Scopus Importer:2020-03-06
Keywords: Greece; Maronia; Porphyry deposit; Potassic alteration; Sodic-calcic alteration; Vein-types

Mineralogical features of Ettringites synthesized from solutions and suspensions - Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; Schwesig, Peter (Proceedings of the 24th International Conference on Cement Microscopy, 2002)
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.LM.minera

Mineralogical, geochemical and isotopic features of tuffs from the CFDDP drill hole: hydrothermal activity in the eastern side of the Campi Flegrei volcano (southern Italy). - Mormone, A.; Troise, Claudia; Piochi, M.; Balassone, G.; Joachimski, Michael; De Natale, Giuseppe (Journal of Volcanology and Geothermal Research, 2015)
A 506. m drill-hole has been recently drilled in the framework of the Campi Flegrei Deep Drilling Project (CFDDP) and the International Continental Scientific Drilling Program (ICDP) with the intention of coring the subsurface in the eastern sector of the Campi Flegrei caldera. The borehole, located in the western district of the Neapolitan city (Bagnoli Plain) 3. km to the east of the most active volcanic area and about 5. m above sea level, is now targeted for monitoring purposes.This paper reports the results obtained from the analysis of two short cores collected at depths of -443 and -506m below the ground level. The cores sampled two pre-caldera tuffs. Observations performed by optical and scanning electron microscopy, energy dispersive spectroscopy and powder X-ray diffraction were used to achieve data on the primary lithology, both primary and secondary mineralogical assemblages, and the relationship between texture and secondary mineralization. Sr isotope ratios were determined on selected primary feldspars, whereas δ13C and δ18O analyses were performed on carbonates from veins and filled-voids in tuffs.Our results provide information on the hydrothermal system in the eastern sector of the caldera that was not among the goals in the previous drilling programs. Secondary mineralization suggests a saline hydrothermal environment characterized by fluids that progressively evolved from boiling toward more alkaline and cooler conditions. A paleo-temperature of ca. 160. °C has been inferred from authigenic mineral occurrences and calculated on the basis of equilibria between cored calcites and fluids presently emitted at the surface, by using carbon and oxygen isotope data. The temperature measured at the bottom of the drilling is about 80. °C.
UnivIS-Import:2015-07-08:Pub.2015.nat.dgeo.IGM.LG.minera
Keywords: Campi Flegrei; Core samples; Geothermal field; Hydrothermal activity; Pilot-hole

Mineralogical, microstructural and magnetic studies on natural pyrrhotite from a 260°C section at the KTB Drilling Site /Germany - Kontny, Agnes; de Wall, Helga; Sharp, Thomas G.; Pósfai, Mihály (American Mineralogist, 2000)
UnivIS-Import:2015-03-09:Pub.2000.nat.dgeo.IGM.c3tekt.minera

Mineralogische Charakterisierung synthetischer Ettringite - Schwesig, Peter; Neubauer, Jürgen (European Journal of Mineralogy, 2000)
UnivIS-Import:2015-03-09:Pub.2000.nat.dgeo.IGM.LM.minera_8

Mineralogy and elemental geochemistry of pyrite coal-balls, Datong Coalfield, Shanxi Province, China: Implications for differentiation mechanism - Hao, Huidi; Huang, Wenhui; Hao, Ruilin; Mu, Nana; Wen, Long; Yu, Chunlan (Ore Geology Reviews, 2023)
The pyrite coal-balls found in No.9 coal of Taiyuan Formation in Dongzhouyao Mine of Datong Coalfield were selected to investigate its mineralogy and elemental geochemistry using optical microscope observation, scanning electron microscopy combined with an energy-dispersive X-ray spectrometer (SEM-EDX), inductively coupled plasma mass spectrometry analysis (ICP-MS), laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS), and electron probe micro-analysis (EPMA). Due to the high content of pyrite, the major-element oxides in the coal-ball samples were mainly Fe2O3, with an average of 62.68 %. LA-ICP-MS results showed that coal-balls were enriched in Tl (CC = 32.79), Pb (CC = 9.22), and Mo (CC = 2.07), while the coals in the same layer were enriched in Ga (CC = 5.31), Tl (CC = 3.66), and Li (CC = 2.27). Affinities to S or Fe and the variation of elemental concentration in the environment during the formation of coal-balls were the primary factor of the elemental differentiation between coals and coal-balls, as well as within coal-balls. The coal-balls formed in four stages in a marine-continental transition environment, with Fe from terrestrial sources and S from marine phases, and its physical origin is basically consistent with that of some Carboniferous-Permian coals in the Datong Coalfield. According to the formation sequence and geochemical characteristics, four periods of pyrite coal-balls evolution have been proposed.
CRIS-Team Scopus Importer:2023-06-30
Keywords: Coal-balls; Datong Coalfield; Formation mechanism; Geochemical characteristics; Mineralogical characteristics

Mineralogy and magnetic behavior of pyrrhotite from a 260°C section at the KTB drilling site, Germany - de Wall, Helga; et al. (American Mineralogist, 2000)

Minor Coral Diversity Loss but Long-Lasting Coral Reef Crises in the Early Paleogene Hothouse - Bosellini, F. R.; Benedetti, A.; Kießling, Wolfgang (Paleoceanography and Paleoclimatology, 2025)
The future of tropical coral reefs is severely threatened by rising global temperatures and relies on the persistence of two key attributes: (a) coral biodiversity, and (b) the reef-building capacity. In order to understand how these attributes responded to a climate warming, we investigated corals and coral reefs in the early Paleogene “hothouse” interval. We focused on the Mediterranean region, which was the global center of reef coral diversity and provides the most complete record for this time interval. We computed biodiversity dynamics of reef corals based on a new compilation of Paleocene to Eocene reef coral occurrences and compared these with coral reef development recorded in the PaleoReefs Database. Extinctions and diversity were within background fluctuations across the Paleocene-Eocene Thermal Maximum (PETM). Coral diversity increased rapidly in the aftermath of the PETM and remained high across the entire Eocene. But reef building collapsed at the PETM and recovered to late Paleocene levels only by the late Eocene. We document that reef corals have demonstrated an excellent resilience within the hothouse, whereas coral reefs were much more vulnerable and took much longer to recover. Our findings suggest that although coral reefs might disappear in the near future, corals will persist and could begin reconstructing reefs once environmental conditions allow.
CRIS-Team Scopus Importer:2025-04-01

Mismatches of threat status and actual extinctions in Quaternary reef corals - Raja, Nussaïbah Begum; Lauchstedt, Andreas; Pandolfi, John M.; Kim, Sun W.; Budd, Ann F.; Kießling, Wolfgang (GSA 2020 Connects Online, 2020)
Species traits and spatial distributions influence the extinction risk of species as a result of abiotic and biotic change. We performed a comparative assessment of the relationship between traits and extinction risk of reef corals in the modern oceans against Plio-Pleistocene reef corals. We chose the Plio-Pleistocene as most of the corals during this time are still present today and their traits are thus comparable to those of modern corals. As such, the regional extinctions of reef corals during this time, attributed to climate change, may shed light on which traits contribute to the resilience or vulnerability of reef building corals in the face of contemporary ocean warming. We applied predictive modelling using two morphological and two distributional traits of 585 extant reef coral species together with data on extinction risk as reported by the International Union for Conservation of Nature (IUCN). This model was then validated against the fossil corals. Although our model performed well in the prediction of the extinction risk of modern corals (82% match), the match between our modelled extinction risk and observed extinction during the Plio-Pleistocene was not better than random. This suggests that either 1) the IUCN status for reef corals may not reflect true extinction risk, or 2) the drivers of extinction during the Plio-Pleistocene may be considerably different from the conditions currently observed in the oceans. This underlines the need to incorporate fossil data when assessing the vulnerability of extant species to climate chang

Mississippian d13Ccarb and conodont apatite d18O records - Their relation to the Late Palaeozoic Glaciation - Buggisch, Werner; Joachimski, Michael; Sevastopulo, George; Morrow, Jared R. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2008)
UnivIS-Import:2015-03-09:Pub.2008.nat.dgeo.IGM.LG.missis

Mistelgau - Schulbert, Christian (2010)
Keywords: Tongrube; Unterer Jura; Mittlerer Jura; Mistelgau

Mixing and transport of water in a karst catchment: A case study from precipitation via seepage to the spring - Barth, Johannes; et al. (Hydrology and Earth System Sciences, 2009)

Mobility, turnover and storage of pollutants in soils, sediments and waters: Achievements and results of the EU project AquaTerra. A review - Barth, Johannes; Grathwohl, P.; Fowler, H. J.; Bellin, Alberto; Gerzabek, M. H.; Lair, G. J.; Barcelo, D.; Petrovic, Mira; Navarro, A.; Negrel, Ph.; Petelet-Giraud, E.; Darmendrail, D.; et al. (Agronomy For Sustainable Development, 2009)

Mobility, turnover and storage of pollutants in soils, sediments and waters: Achievements and results of the EU project AquaTerra - A review - Barth, Johannes; Grathwohl, P.; Fowler, H. J.; Bellin, Alberto; Gerzabek, M. H.; Lair, G. J.; Barcelo, D.; Petrovic, Mira; Navarro, A.; Negrel, Ph.; Petelet-Giraud, E.; Darmendrail, D.; et al. (2009)

Model for economic evaluation of closed-loop geothermal systems based on net present value - Xiao, Dong; Liu, Mingjie; Li, Li; Cai, Xinhui; Qin, Shan; Gao, Ruoyu; Liu, Jianhong; Liu, Xiantao; Tang, Haijun; Li, Gao (Applied Thermal Engineering, 2023)
Closed-loop geothermal systems (CGSs) represent an effective means of extracting low-grade thermal energy from hot dry rock (HDR). Thus far, there has been much debate on whether they can be profitable because no economic evaluation model has been available. This study highlights the profitability of geothermal projects by developing a techno-economic coupling model for economic evaluation of CGSs based on net present value (NPV) for the first time. The proposed model was applied and analyzed in the case of the Gonghe Basin, Qinghai, China. The results indicate the following conclusions. (1) The technical model was extremely accurate, and the results were consistent with experimental results and the results of calculations using other classical models (the relative errors were all less than 9.8 %). (2) In terms of the heat extraction effect, the heat extraction power of U-shaped closed-loop geothermal systems (UCGSs) is ∼ 1.3 times that of coaxial closed-loop geothermal systems (CCGSs). The heat extraction power for direct heating is ∼ 1.1 times that for electricity generation. (3) Increasing the rate of the one-off government subsidy to 30 %, increasing the heat price by 30 %, and reducing the drilling cost by 30 % can make a CGS profitable within a production time of 50 years. This study will serve as a theoretical foundation for policymakers and engineers to develop HDR resources using CGSs.
CRIS-Team Scopus Importer:2023-07-07
Keywords: Closed-loop geothermal system; Economic evaluation; Hot dry rock; Net present value; Techno-economic coupling model

Modeling and experiments on energy loss in horizontal connecting pipe of vertical ground source heat pump system - Luo, Jin; Bayer, Manfred; Prieß, Anna; Rohn, Joachim (Applied Thermal Engineering, 2013)
Keywords: Energy loss; Ground source heat pump system; Horizontal connecting pipe; Pipe burial depth Heat carrier fluid; Pipe insulation

Modeling the carbon and sulfur isotope compositions of marine sediments: climate evolution during the Devonian. - Buggisch, Werner; Joachimski, Michael; et al. (Chemical Geology, 2007)
A model of global biogeochemical cycles coupled to an energy-balance climatic model (modified after the COMBINE model; [Goddéris, Y., Joachimski, M.M., 2004. Global change in the Late Devonian: modeling the Frasnian-Famennian short-term carbon isotope excursions. Palaeogeogr. Palaeoclimatol. Palaeoecol. 202, 309-329]) is used to calculate the short-term evolution of atmospheric pCO2 during the Devonian. The geochemical cycles for carbon, alkalinity, phosphorus, sulfur and oxygen are included in this model, with also 13C and 34S cycles. High-resolution records of δ13C of marine carbonates and δ34S of marine sulfates are used as forcing parameters of the geochemical cycles in an inverse modeling. Atmospheric pCO2 and pO2 at the end of the Silurian are calculated to have been 3000 ppmv and 0.165 bar (0.75 PAL), respectively. A long-term decrease in pCO2 is modeled for almost the entire Devonian. Short-term lowering of pCO2 to concentrations around 2000 ppmv is calculated for the Silurian-Devonian transition and the Pragian. Contents around 900 ppmv are modeled for the Eifelian-Givetian, Givetian-Frasnian and Frasnian-Famennian boundaries as a consequence of enhanced organic carbon burial during deposition of Lochkovian, Eifelian, and Frasnian grey and black shales. Organic carbon burial is enhanced by the increase of phosphorus delivery to the ocean triggered by short-term sea-level falls. The corresponding short-term global climatic cooling at the Silurian-Devonian boundary, at the end of the Pragian, and the Givetian-Frasnian as well as Frasnian-Famennian boundaries reached 2 °C at the equator. The rapid colonization of continental surface by land plants during the Middle and Late Devonian, increasing chemical alteration of the continents and CO2 consumption by silicate weathering, is assumed to have caused cooling of surface seawater, as suggested by the δ18O values of biogenic apatites. © 2007 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LG.modeli
Keywords: Carbon; Carbon dioxide; Devonian; Isotope ratios; Modeling; Sulfur

Modelle zur Kinetik der Hydratation von Calciumaluminatzement mit Calciumsulfat aus kristallchemischer und mineralogischer Sicht - Götz-Neunhoeffer, Friedlinde (Universitätsbund Erlangen-Nürnberg, 2006)
Zur Klärung der Phasenentwicklung während der Hydratation von Calciumaluminatzement bei 23 °C wurden Röntgenbeugungsaufnahmen von hydratisierenden Pasten ausgewertet. Der Verlauf der Phasenbildung kann damit in situ dokumentiert werden. Die Pasten wurden innerhalb eines Zeitraumes von 24 h in kurzen Abständen wiederholt röntgenbeugungsanalytisch untersucht. Das Ergebnis der quantitativen Phasenanalyse der Calciumaluminatzementpasten in Kombination mit den zeitabhängigen Daten der Wärmeflusskalorimetrie ermöglicht Modelle zur Hydratation von Calciumaluminatzement bei Anwesenheit von Calciumsulfat, Li+ und Weinsäure zu entwickel
UnivIS-Import:2015-04-02:Pub.2006.nat.dgeo.IGM.LM.modell_8

Modelling an induced thermal plume with data from electrical resistivity tomography and distributed temperature sensing: a case study in northeast Italy - Cultrera, Matteo; Boaga, Jacopo; Di Sipio, Eloisa; Dalla Santa, Giorgia; De Seta, Massimiliano; Galgaro, Antonio (Hydrogeology Journal, 2017)
Groundwater tracer tests are often used to improve aquifer characterization, but they present several disadvantages, such as the need to pour solutions or dyes into the aquifer system and alteration of the water’s chemical properties. Thus, tracers can affect the groundwater flow mechanics and data interpretation becomes more complex, hindering effective study of ground heat pumps for low enthalpy geothermal systems. This paper presents a preliminary methodology based on a multidisciplinary application of heat as a tracer for defining the main parameters of shallow aquifers. The field monitoring techniques electrical resistivity tomography (ERT) and distributed temperature sensing (DTS) are noninvasive and were applied to a shallow-aquifer test site in northeast Italy. The combination of these measurement techniques supports the definition of the main aquifer parameters and therefore the construction of a reliable conceptual model, which is then described through the numerical code FEFLOW. This model is calibrated with DTS and validated by ERT outcomes. The reliability of the numerical model in terms of fate and transport is thereby enhanced, leading to the potential for better environmental management and protection of groundwater resources through more cost-effective solutions
Keywords: Electrical resistivity tomography . Numerical modeling . Tracer tests . Thermal response test . Distributed temperature sensing

Modelling multiseasonal preferential transport of dissolved organic carbon in a shallow forest soil: Equilibrium versus kinetic sorption - Dusek, Jaromir; Dohnal, Michal; Vogel, Tomas; Marx, Anne; Barth, Johannes (Hydrological Processes, 2019)
Parameterization of transformation and transport processes of dissolved organic carbon (DOC) in soils is challenging especially under variable hydrological conditions. In this study, DOC concentrations in stormflow were analysed with a physically based modelling approach. A one-dimensional dual-continuum vertical flow and transport model was applied to simulate subsurface processes in a macroporous forest hillslope soil over a period of 4.5 years. Microbially mediated transformations of DOC were assumed to depend primarily on soil moisture and soil temperature. Two conceptually different descriptions of the sorption of DOC to soil were examined with equilibrium and kinetic approaches. In order to quantify the uncertainties associated with the model parameterization, Monte Carlo analyses in conjunction with Latin hypercube sampling was performed. Despite the complexity of microbial transformations, the simulated temporal patterns of DOC concentrations in stormflow showed similar behaviour to those reflected in the observed DOC fluxes. Due to preferential flow, the hillslope DOC export (5.0 ± 0.5 g C · m−2 · year−1) was higher than the amounts usually reported in the literature. Overall DOC transport in hillslope scenarios could be described appropriately using the equilibrium sorption assumption. The performed analyses showed that the inclusion of the kinetic description of DOC sorption only slightly improved the predictions of the DOC hillslope export. Moreover, influences of seasonal hydro-climatological conditions on hillslope export of DOC could be observed. Reduced DOC transport during an extreme warm and dry summer was described with lower accuracy, thus indicating the difficulties in the representation of DOC transformations under dry conditions.
CRIS-Team Scopus Importer:2019-09-03
Keywords: dissolved organic carbon; DOC adsorption/desorption; dual-permeability model; hillslope discharge; kinetic sorption; Monte Carlo analysis; preferential transport; uncertainty

Modelling spatial permeability distributions in fine-grained sediments on a meter scale - Drews, Michael; Kurtev, Kuncho; Ma, Jingsheng; Aplin, Andrew; et al. (6th IMA Conference on Modelling Permeable Rocks, 2010)

Modelling Thermo-Hydraulic Coupled Phase Change Processes of BHE Induced Ground Freezing - Dalla Santa, Giorgia; Galgaro, Antonio; Farina, Zeno; Di Sipio, Eloisa; Anbergen, Hauke; Rühaak, Wolfram (EGC 2016- European Geothermal Congress Proceedings, 2016)
Keywords: Ground source heat pump; operating temperature; FEFLOW; freeze-thaw cycles; thermal conductivity; thermal plume

Modelling vSGPs (very shallow geothermal potentials) in selected CSAs (case study areas). - Bertermann, David; Klug, Hermann; Morper-Busch, Lucia; Bialas, Christian (Energy, 2014)
Very shallow geothermal energy resources are amongst the RES (renewable energy sources). They can be expressed as TC (thermal conductivity) (W/m*K) and VHC (volumetric heat capacity) (MJ/m3*K) of unconsolidated ground, and can be obtained from a depth of 10m below the Earth's surface. Utilising horizontal and vertical heat collector systems, these geothermal energy sources can be harnessed for heating and cooling purposes of residential and industrial buildings. To ensure proper prediction of available potentials at landscape or even local scale, downscaling of the already existing pan-European vSGP (very shallow geothermal potential) at a scale of 1:250,000 is required. Therefore, we applied an advanced methodology to 14 European CSAs (case study areas) from which we selected two German and one Austrian area for demonstration purposes. To ensure comparability across CSAs, national and case study related datasets were standardised and harmonised. Standards and unified spatial data processing methods across CSAs ensure comparability and seamless visualisation. Laboratory investigations on TC demonstrate valid modelling results for three depth layers, visualised in a publicly available WebGIS. © 2014 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LG.modell
Keywords: Heat transfer; Particle-size fraction; Soil water content; Spatial analysis; TC (thermal conductivity); VHC (volumetric heat capacity); Geologie; erneuerbare Energiequelle; Bodenkunde

Modern brackish bryostromatolites (“bryoliths”) from Zeeland (Netherlands) - Harrison, G. William M.; Claußen, Anna Lene; Schulbert, Christian; Munnecke, Axel (Palaeobiodiversity and Palaeoenvironments, 2021)
Bryostromatolites are found in stressed environments from the Paleozoic to the Recent. They are formed by alternating layers of bryozoans and microbes. This study investigates recent bryostromatolites in brackish ponds in the Netherlands to better understand ancient analogues and the environments which hosted them. They formed a fringing reef at the site Ronde Weel and a barrier reef at Kaaskenswater. The ponds had low biodiversity with only one bivalve species, two gastropod species, one ostracod species, and three diatom species comprising most of the easily fossilizable taxa; one isopod species, one decapod species, and two polychaete species were also present. Observations of microbial layers and cementation practices indicate that an alternation of bryozoan-favouring conditions and microbe-favouring conditions is essential to forming bryostromatolites. The collected bryostromatolites only had tiny living bryozoan patches. Water tests confirmed a brackish environment but with enriched arsenic and titanium concentrations and periodic euxinia. The extreme environment explains the lack of biodiversity and may provide information about the environments in which past bryostromatolites formed.<br
Keywords: Bryozoan; Bryostromatolite; Reef

Modularity explains large-scale reef booms in Earth’s history - Raja, Nussaïbah Begum; Pandolfi, John M.; Kießling, Wolfgang (Facies, 2023)
Drivers of reef decline are well known both today and in the geological past. Considerably less is known about the preconditions for a pantropical expansion of coral reefs. The geological record of reef building is characterised by considerably long intervals with very limited reef expansion and geologically brief (< 20 million years) episodes of prolific, pantropical reef growth. Here, we propose a new "co-occurrence hypothesis" (COH), which posits that reefs thrive when fast-growing hypercalcifiers co-occur with encrusting organisms such as calcifying microbes or coralline algae to construct wave-resistant structures. While there is little evidence of the effect of abiotic drivers on reef proliferation, we find that positive co-occurrence patterns are significantly more common in reefal as compared to non-reefal communities, suggesting that biological interactions are more relevant in reefs than in non-reefs. Supporting COH, we also show that reefs after the end-Permian mass extinction became more modular in nature with limited membership in reef assemblages during reef booms than in typical periods of reef growth (background intervals). Modularity in reefs may have led to the stabilisation of reef ecosystems, giving them the ability to recover from small perturbations, promoting reefal carbonate accretion and prolific reef growth.
CRIS-Team Scopus Importer:2023-07-07
Keywords: Co-occurrence; Modularity; Palaeobiology; Reefs

Mo.nalis.a: a methodological approach to identify how to meet thermal industrial needs using already available geothermal resources - Bruno, Delia Evelina; Lombardo, Giuseppe; Di Sipio, Eloisa; Galgaro, Antonio; D' Arpa, Stefania; Destro, Elisa; Passarella, Giuseppe; Barca, Emanuele; Auricchio, Vito Felice; Manzella, Adele (Energy Efficiency, 2017)
Keywords: Energetic model; Geothermal heat; Groundwater and ground source heat pumps; Industrial thermal needs; Renewable energy

Monazite CHIME/EPMA dating of Erinpura granitoid deformation: Implications for Neoproterozoic tectono-thermal evolution of NW India - Just, Jana; Schulz, Bernhard; de Wall, Helga; Jourdan, Fred; Pandit, Manoj K. (Gondwana Research, 2011)
Keywords: Ar-Ar muscovite age; CHIME/EPMA monazite dating; Erinpura granite; NW India; Shear zone

Monitoring of cap-rock integrity during CCS from field data at the Ketzin pilot site (Germany): Evidence from gas composition and stable carbon isotopes - Barth, Johannes; Nowak, M. E.; Zimmer, M.; Norden, B.; van Geldern, Robert (International Journal of Greenhouse Gas Control, 2015)

Morphological characters and ontogenetic development of deep-sea species of the genus Caryophyllia - Vertino, Agostina; Stolarski, Jarosław; Schulbert, Christian (13th International Symposium onFossil Cnidaria and PoriferaModena, ABSTRACT BOOK, 2019)
The genus Caryophyllia is known from shallow- to deep-waters in all oceans and seas of the planet and itincludes 66 valid Recent species. Though frequently reported as fossil, at least since the Upper Jurassic, thedistribution of valid Caryophyllia species in the paleontological record is still unknown. Only consideringthe Neogene and Pleistocene deposits of the Mediterranean, over 100 species are mentioned in the ancientliterature but they have never been revised following modern taxonomic concepts. The diagnostic taxonomic character that distinguishes the genus Caryophyllia from the other genera ofthe family Caryophylliidae is the presence of pali before the penultimate, rarely the antepenultimate cycle ofsepta. Mitochondrial 16S rRNA phylogeny analyses of modern species support grouping Caryophyllia in oneclade, however, two other taxa included in this clade (Crispatotrochus rugosus and Dasmosmilia lymani) donot develop pali (Crispatotrochus) or develop structures called paliform lobes before all but the last septalcycle. The distinction between pali and paliform lobes remains ambiguous not only in Caryophyllia but inseveral other scleractinian taxa. For that reason, precise documentation of ontogenetic development of bothskeletal structures is of general importance for scleractinian coral researchers. This study aims at describing the morphological variability and ontogenetic development of deep-sea Caryophyllia species collected from Pleistocene deposits of southern Italy and from modern seafloors of theMediterranean and the NE Atlantic. By analysing SEM and micro-CT images, as well as polished and thinsections, particular attention has been devoted to (1) the micromorphology of the coral wall and calicularfeatures and (2) the arrangement and ontogenetic development of pal
Keywords: Corals; Cariophyllia; micro-CT; µCT; ontogeny

Morphological disparity and ontogeny of the endemic heteromorph ammonite genus Aegocrioceras (Early Cretaceous, Hauterivian, NW-Germany) - Hoffmann, René; Weinkauf, Manuel; Wiedenroth, Kurt; Goeddertz, Peter; de Baets, Kenneth (Palaeogeography, Palaeoclimatology, Palaeoecology, 2019)
Despite the fact that heteromorph ammonites often show a large range of intraspecific variation, that variation has rarely been quantified. Here, we quantify the intraspecific variation and ontogeny of 85 newly collected specimens of the Hauterivian endemic ammonite genus Aegocrioceras. All specimens were collected from concretions in the recently exposed bed 82 in the clay pit Resse in NW Germany (Lower Saxony Basin). Data for the conch morphology (diameter, whorl height, whorl interspace, rib spacing) were collected in 45° steps using the new software CONCH©. The CONCH© software will be made officially available with this publication. All ammonites were a priori identified as A. bicarinatum or A. semicinctum. An assessment of the intra- and interspecific variation as well as the ontogeny of this assemblage demonstrates the presence of just one species, i.e., A. bicarinatum. Comparison with the type material of A. bicarinatum and A. semicinctum reveals a large morphological overlap of different conch parameters and does not support a separation of both forms as distinct species. The analyzed assemblage of A. bicarinatum has a high variation in conch morphology including whorl interspace, umbilical width, and whorl expansion. Furthermore, the changes in intraspecific variation through ontogeny were quantified and the presence or absence of sexual dimorphism within the assemblage is discusse
Keywords: Aegocrioceras bicarinatum; Aegocrioceras semicinctum; Systematics; Sexual dimorphism; Morphometric measurement software CONCH©

Morphological response accompanying size reduction of belemnites during an Early Jurassic hyperthermal event modulated by life history - Nätscher, Paulina; Dera, Guillaume; Reddin, Carl J.; Rita, Patrícia; de Baets, Kenneth (Scientific Reports, 2021)
One of the most common responses of marine ectotherms to rapid warming is a reduction in body size, but the underlying reasons are unclear. Body size reductions have been documented alongside rapid warming events in the fossil record, such as across the Pliensbachian-Toarcian boundary (PToB) event ( 183 Mya). As individuals grow, parallel changes in morphology can indicate details of their ecological response to environmental crises, such as changes in resource acquisition, which may anticipate future climate impacts. Here we show that the morphological growth of a marine predator belemnite species (extinct coleoid cephalopods) changed significantly over the PToB warming event. Increasing robustness at different ontogenetic stages likely results from indirect consequences of warming, like resource scarcity or hypercalcification, pointing toward varying ecological tolerances among species. The results of this study stress the importance of taking life history into account as well as phylogeny when studying impacts of environmental stressors on marine organisms.
CRIS-Team Scopus Importer:2021-08-06

Morphological traits of reef corals predict extinction risk but not conservation status - Raja, Nussaïbah Begum; Lauchstedt, Andreas; Pandolfi, John M.; Kim, Sun W.; Budd, Ann F.; Kießling, Wolfgang (Global Ecology and Biogeography, 2021)
Aim The current assessment of extinction risk in reef corals by the International Union for Conservation of Nature (IUCN) has been criticized, because coral life-history traits associated with resilience are not reflected in the conservation status. We aimed to carry out a quantitative assessment of the link between reef coral traits and species extinction risk informed by extinctions of reef corals observed in the fossil record. Location Global. Time period Plio-Pleistocene and present day. Major taxa studied Scleractinian reef corals. Methods We used morphological traits, phylogenetic information and evidence of extinction during the Plio-Pleistocene to predict the extinction risk of contemporary reef corals. Our model was trained using 138 Caribbean fossil coral species and an automatic machine learning algorithm. We then used this model to predict the extinction risk of 674 modern coral species. Results Model validation confirmed 77% accuracy in predicting extinction risk of fossil corals. Extinction risk predicted by our model showed a near-random (57%) match with the IUCN conservation status. Our model also suggested that corals in the Least Concern or Near Threatened categories might be at higher risk of extinction than currently believed. Main conclusions Morphological traits of fossil corals linked to their extinction risk in the Plio-Pleistocene Caribbean Sea are known to reflect the vulnerability of extant corals. However, the results from our fossil-calibrated model do not match the IUCN assessment of reef corals, with increased overall extinction risk. This does not necessarily indicate near-future extinction risk, because fossil extinctions are spread over thousands of years. However, we show the applicability of using fossil data to inform the extinction risk of modern corals and recommend that future assessments of extinction risk of reef corals should consider incorporating the relationship between morphological traits and resilience, calibrated by fossil data, to maximize the utility of the extinction risk assessment. <br
Keywords: extinction risk; fossil record; predictive modelling; Red List; reef corals; traits

Morphological trends in reticulate Nummulites across the Eocene–Oligocene transition - Koorapati, Ravi Kiran; Moon, Benjamin C.; Cotton, Laura J. (Palaeontology, 2025)
At the Eocene–Oligocene transition (EOT), c. 34.44–33.65 Ma, the Earth's climate shifted from ‘greenhouse’ to ‘icehouse’ conditions. This change coincides with the first continental ice growth on Antarctica, global cooling, and widespread overturning of faunal and floral assemblages. Studies have focused on the timing and mechanism of larger foraminiferal extinctions across the EOT, but there has been little work on surviving taxa. Reticulate Nummulites are a morphologically distinctive and biostratigraphically important lineage ranging from the lower Eocene to the Oligocene, surviving the climatic change. While general long-term trends across the entire lineage are well established, no previous study has examined in detail the potential of climatic events on their evolution. The Tanzania Drilling Project recovered three drill core records crossing the EOT. These are exceptionally well-constrained stratigraphically, and contain specimens of well-preserved reticulate Nummulites throughout. Using traditional oriented thin sections and micro-computed tomographic scanning, we examined the morphology of 157 individual specimens from before, during and after the EOT. Significant increases are seen in proloculus size, radii of inner whorls, and total number of whorls. Our results also show a clear expansion in morphospace across the EOT, which we interpret as a speciation event in progress linked to the climatic shift. Modelling suggests that there is a relationship between the δ18O and δ13C records and morphological change, indicating that factors such as temperature and nutrient cycling may play a role. However, driving mechanisms appear to vary both through time and maybe even within the growth of the foraminifera.
CRIS-Team Scopus Importer:2025-04-01
Keywords: climate; Eocene; evolution; larger foraminifera; speciation; survivor

Morphological variability of peteinoid acritarchs from the Middle Ordovician of Öland, Sweden, and implications for acritarch classification - Kroeck, David M.; Eriksson, Mats E.; Lindskog, Anders; Munnecke, Axel; Dubois, Michel; Regnier, Sylvie; Servais, Thomas (Palynology, 2021)
Investigation of large populations of peteinoid acritarchs recovered from Middle Ordovician strata of the Hälludden and Horns Udde quarry sections (Öland, Sweden) allows for statistical analyses based on morphometric measurements. The results indicate the presence of assemblages with a continuous variability of morphotypes, thus a distinction of different peteinoid acritarch taxa in the sections proved to be impossible. This challenges the currently accepted classification based on a differentiation into the three genera Peteinosphaeridium, Cycloposphaeridium and Liliosphaeridium, and a multitude of different species; individual taxa are essentially arbitrary as morphotypes intergrade. Investigations on modern dinoflagellates show that these can develop variable cyst morphologies depending on environmental factors. By analogy, it can be hypothesised that the different morphologies observed among the peteinoid acritarchs from Öland are cysts produced by only very few phytoplanktic organisms (or even a single species) with high morphological variability.
CRIS-Team Scopus Importer:2021-06-04
Keywords: ecophenotypism; Palaeozoic Darriwilian; Phytoplankton; taxonomy

Morphology and fluvio-aeolian interaction of the tropical latitude, ephemeral braided-river dominated Koigab Fan, north-west Namibia. - Krapf, Carmen; Stanistreet, Ian G.; Stollhofen, Harald (Fluvial Sedimentology VII, 2005)
The Koigab Fan is the largest of the active fan systems formed by some of the west-south-west flowing ephemeral river systems of the Skeleton Coast area, north-west Namibia. Issuing from the volcanic Etendeka Plateau, the Koigab River flows towards the Atlantic Ocean across a considerable climatic gradient from semi-arid summer rainfall in the mountainous catchment, to hyperarid in the coastal depositional setting. The morphology of channels can be discerned over the whole fan surface (gradient 1.011), the majority of which appears as a vast deflation surface on which lithic and heavy mineral grains are concentrated by aeolian removal of fines. The Koigab catchment restricts source-rock lithologies to flood basalts and interleaved quartz latites of the Etendeka Plateau, so components that unequivocally relate to a volcanic source (e.g. volcanic lithics, Ti-magnetite, pyroxenes) indicate fluvial transport, whereas grains reflecting a metamorphic basement source (e.g. garnet, muscovite, staurolite) must be aeolian derived. Both heavy mineral and grain-size data were used to estimate the amount of fluvio-aeolian interaction at the Koigab Fan surface. This aspect is significant because it comprises not only winnowing of the fan surface and of ‘fresh’ sandy channel deposits but also fluvial recycling of aeolian material. The contribution of aeolian-derived grains to river deposits increases from 5% in the fan apex area to as much as 50% in the distal fan reaches. In the spectrum of fan types, the Koigab Fan takes an intermediate position both in size and in terms of the braided river style between debris flow and low sinuosity meandering fan systems. Within the braided fluvially dominated fan class itself the Koigab Fan is also intermediate in size, but its ephemeral channels contrast sharply with those of perennial glacial outwash fans previously described from the sub-Arctic. Within low-latitude fan systems, the Koigab also contrasts with other highly vegetated fans in the tropics, for example the subaerial portion of the Yallahs Fan-delta, Jamaica. Thus, the Koigab Fan is important as a potential analogue for Precambrian and early Palaeozoic low-latitude fan systems that lacked surface vegetation prior to the evolution of land plants.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LG.morpho

Morphology and systematics of fossil and recent sea pens (Octocorallia: Pennatulacea) - Roden, Vanessa; Reich, Mike (12th International Symposium on Fossil Cnidaria and Porifera 2015 - Abstract Volume, 2015)

Morphotectonic analysis of basement and cover units in eastern Bavaria, SE Germany - insights into the deeper crustal architecture? - Eberts, Andreas; Schaarschmidt, Anna; Bauer, Wolfgang; Stollhofen, Harald; de Wall, Helga (GeoBonn 2018, 2018)
The topographic expression of landscapes directly depends on the interaction between exposed rock type, erosion and tectonic deformation. In areas where high rates of active deformation pre-vail, the effects of faulting and folding are often immediately transferred to the Earth’s surface. By contrast, in areas where ongoing, rapid deformation is absent, as it is assumed for large parts of eastern Bavaria, erosional processes need to utilize gradients in erodibility to uncover already existent tectonic structures. In that case, resulting topographic features are not visible as well-defined fault scarps but as linear to curvilinear river valleys, ridgelines or slope breaks. Because these lineaments outline structures that formed during ancient tectonic events, mapping of them yields important information about the general structural framework of the subsurface. Here, we present results from an integrated study, using high-resolution digital elevation models from airborne LiDAR surveys combined with gravity data to reveal the morphotectonic feature inventory of eastern Bavaria, SE Germany, and its relation to the underlying crustal architecture. The studied area comprises the western border zone of the Bohemian Massif, a region well known for hosting some of the largest fault zones existing in Central Europe, such as the Pfahl Fault Zone (PFZ) and Danube Fault Zone (DFZ). Post-Variscan to Alpine reactivation of earlier struc-tures led to a complex structural pattern along these faults and ultimately resulted in the uplifted and exposed basement complex of the Bohemian Massif. Our results show that the investigated area is segmented into several domains of different orders. 1st order domains, best delineated in gravity data, are thought to represent large crustal blocks which partly root into the upper mantle. These are assigned to the Saxothuringian, Teplá-Barran-dian and Moldanubian crustal units. In contrast, 2nd order domains additionally show distinct var-iations in the arrangement of topographic lineaments and in other DEM-specific parameters such as surface roughness indices and altitude distributions. In the Bavarian Forest, for example, a central domain of high gravity is also characterized by predominantly N-S oriented lineaments and an increased surface roughness. Furthermore, 2nd order domains are separated by large topographic lineaments, some of which situated in close vicinity to already known fault zones such as the PFZ and DFZ. However, our study also identifies previously unknown locations of ancient fault zones, ultimately indicating an even more complex structural evolution and crustal architecture of eastern Bavaria and the western border zone of the Bohemian Massif.<br

Mosses like it rough-growth form specific responses of mosses, herbaceous and woody plants to micro-relief heterogeneity - Leutner, Benjamin; Steinbauer, Manuel; Müller, Carina; Früh, Andrea; Irl, Severin; Jentsch, Anke; Beierkuhnlein, Carl (Diversity, 2012)
Micro-relief heterogeneity can lead to substantial variability in microclimate and hence niche opportunities on a small scale. We explored the relationship between plant species richness and small-scale heterogeneity of micro-relief on the subtropical island of La Palma, Canary Islands. Overall, we sampled 40 plots in laurel and pine forests at four altitudinal bands. Species richness was recorded separately for various growth forms (i.e., mosses, herbaceous and woody plants). Site conditions such as altitude, slope, aspect, and tree density were measured. Micro-relief heterogeneity was characterized by surface structure and a subsequently derived surface heterogeneity index. The effect of micro-relief heterogeneity on species richness was analysed by means of linear mixed effect models and variance partitioning. Effects of micro-relief heterogeneity on species richness varied considerably between growth forms. While moss richness was affected significantly by micro-relief heterogeneity, herbaceous and woody plants richness responded mainly to larger-scale site conditions such as aspect and tree density. Our results stress the importance of small-scale relief heterogeneity for the explanation of spatial patterns of species richness. This poses new challenges as small-scale heterogeneity is largely underrepresented, e.g. with regard to its application in species distribution models.
Keywords: Altitudinal gradient; Biodiversity; Bitterlich; Climate change; Habitat heterogeneity; Laurel forest; Micro-topography; Northernness; Species diversity; Topographic variability

Multidimensional Scaling of Varietal Data in Sedimentary Provenance Analysis - Vermeesch, P.; Lipp, A. G.; Hatzenbühler, D.; Caracciolo, Luca; Chew, D. (Journal of Geophysical Research F: Earth Surface, 2023)
Varietal studies of sedimentary provenance use the properties of individual minerals or mineral groups. These are recorded as lists of numerical tables that can be difficult to interpret. Multidimensional Scaling (MDS) is a popular multivariate ordination technique for analyzing other types of provenance data based on, for example, detrital geochronology or petrography. Applying MDS to varietal data would allow them to be treated on an equal footing with those other provenance proxies. MDS requires a method to quantify the dissimilarity between two samples. This paper introduces three ways to do so. The first method (“treatment-by-row”) turns lists of (compositional) data tables into lists of vectors, using principal component analysis. These lists of vectors can then be treated as “distributional” data and subjected to MDS analysis using dissimilarity measures such as the Kolmogorov-Smirnov statistic. The second method (“treatment-by-column”) turns lists of compositional data tables into multiple lists of vectors, each representing a single component of the varietal data. These multiple distributional data sets are subsequently subjected to Procrustes analysis or 3-way MDS. The third method uses the Wasserstein-2 distance to jointly compare the rows and columns of varietal data. This arguably makes the best use of the data but acts more like a “black box” than the other two methods. Applying the three methods to a detrital titanite data set from Colombia yields similar results. After converting varietal data to dissimilarity matrices, they can be combined with other types of provenance data, again using Procrustes analysis or 3-way MDS.
CRIS-Team Scopus Importer:2023-04-07
Keywords: apatite; provenance; sediment; statistics; titanite; zircon

Multi-Phase Dolomitization in the Jurassic Paleo-Oil Reservoir Zone, Qiangtang Basin (SW China): Implications for Reservoir Development - Hao, Ruilin; Pan, Liyin; Mu, Nana; Li, Xi; Fu, Xiaodong; Xiong, Shaoyun; Liu, Siqi; Zheng, Jianfeng; She, Min; Munnecke, Axel (Minerals, 2024)
The age and dolomitization processes in the Paleo-oil reservoir zone, which is composed of massive dolostones found in the Qiangtang Basin (SW China), are still debated. In this research, the Long’eni-Geluguanna Area was selected. Macroscopic information, thin sections, and geochemical methods were used to investigate the dolomitization characteristics and the processes that controlled dolomitization. Five types of replacive dolomites and two types of dolomite cement were observed. Some of the dolomites displayed ghosts of primary sedimentary structures. Saddle dolomites were prevalent, occurring in the interparticle and moldic pores of the limestone which should have been filled at an early diagenetic stage. Ten microfacies types were identified. The foraminifera assemblage provides evidence that the studied interval is of Early Jurassic age. The δ13C values are similar to the contemporaneous seawater signature. The REE+Y patterns of limestones and dolostones exhibit similarities to that of seawater. The mean Na and Sr values are comparable to those of other near-normal seawater dolomites. The δ18O values of all lithologies are markedly depleted. The dolomitization started penecontemporaneously, with deposition. A general sand shoal setting with patch reefs developed. The dolomitizing fluids, near-normal seawater, was probably formed by slight evaporation on top of the shoal. Saddle dolomites in the interparticle and moldic pores might indicate hydrothermal activity, which also caused the recrystallization of some pre-existing dolomites. The recrystallization might have slightly increased the crystal size, demolished the ghost structures, formed saddle dolomites, and altered the REE+Y patterns. The recrystallization extent diminished with increasing distance from the fluids-providing fracture. Furthermore, the existence of protected areas within the sand shoal settings could enhance the vertical and horizontal heterogeneity of dolostone reservoirs.
CRIS-Team Scopus Importer:2024-10-04
Keywords: dolomitization; dolostone; microfacies analysis; Qiangtang basin; sedimentary environment

Multiple ways of producing intermediate and silicic rocks within Thingmúli and other Icelandic volcanoes - Charreteur, Gilles; Tegner, Christian; Haase, Karsten (Contributions To Mineralogy and Petrology, 2013)
Major and trace element compositions of rocks and coexisting phenocrysts of the Thingmúli volcano suggest a revision of the existing models for the formation of intermediate and silicic melts in Iceland. The new data define two compositional tholeiitic trends with a significant gap between them. A high-iron trend (HFe) contains 6-14 wt% total FeO in silicic rocks with c. 1 wt% MgO, as well as sodic plagioclase and hedenbergite phenocrysts. A low-iron trend (LFe) contains 3-5 wt% FeO at c. 1 wt% MgO, which is typical of Iceland but higher than MORB compositions. The most evolved phenocrysts of the LFe trend do not reach iron-rich end members. The HFe trend is interpreted as a result of fractional crystallization; numerical modelling using the MELTS algorithm suggests that crystallization took place under redox conditions constrained to one-log unit below the fayalite-magnetite-quartz oxygen buffer (FMQ-1). The LFe trend is explained by a combination of mixing between rhyolite and ferrobasalt, assimilation of hydrated crust and fractional crystallization under higher redox conditions (FMQ). The two trends and the gap are best defined in a plot of Mg# versus SiO that is useful to unravel petrogenetic processes. For example, intermediate and silicic rocks of the Holocene volcanic systems of spreading rifts (e.g. Krafla), propagating rifts (e.g. Hekla) and off-rifts (Öræfajökull) also fall into high- and low-iron fields and outline a gap similar to Thingmúli. The identification of two compositional trends in erupted intermediate and silicic volcanic products shows that processes in the deep roots of single volcanic systems are highly diverse and likely controlled by local variations in the thermal gradients and the extend of hydrothermal alteration. Generalizations about the relationship between the compositions of intermediate and silicic rocks and plate tectonic setting, therefore, should be avoided. © 2013 Springer-Verlag Berlin Heidelberg.
Keywords: Basalt; Fractional crystallization; Iceland; Intermediate rocks; Magma mixing; Rhyolite; Thingmuli volcano

Multi-proxy approach involving ultrahigh resolution mass spectrometry and self-organising maps to investigate the origin and quality of sedimentary organic matter across a subtropical reservoir - Jeunon Gontijo, Erik Sartori; Herzsprung, Peter; Lechtenfeld, Oliver J.; Bueno, Carolina De Castro; Barth, Johannes; Rosa, Andre H.; Friese, Kurt (Organic Geochemistry, 2021)
Humic substances (HS) in sediments play an important role in carbon and nutrient biogeochemical cycles and fate of contaminants in the environment. However, information regarding HS quality and transformations that may affect their behaviour in reservoirs is still limited. The aim of this investigation was to track sources and changes in sedimentary HS across a subtropical reservoir, connecting them to in lake processes and land-use influences. Surface sediments were collected at seven sampling sites in Itupararanga Reservoir (Brazil). Humic (HA) and fulvic (FA) acids (components of HS) were extracted from the sediment samples followed by in-depth characterisation via UV/VIS, fluorescence spectroscopy, elemental (C, N) and isotopic analysis (delta C-13, delta N-15), nuclear magnetic resonance (C-13 NMR) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). All data were analysed by self organising maps. The results showed that samples from the upstream part of the reservoir were older and more decomposed. They likely originated from C3 land-plants (delta C-13 varied from -26.3 parts per thousand to -22.4 parts per thousand), having more aromatic, oxygen-poor (O/C < 0.5) and unsaturated compounds (H/C 1.1). In contrast, near-dam samples were younger and had larger contributions of autochthonous material. This was confirmed by oxygen-rich (O/C 0.5) and partly more unsaturated compounds for FA as well as oxygen poor and saturated compounds with H/C > 1.1 for HA. Self-organising maps pointed out these differences between upstream and dam areas and indicated that agriculture lands were related to microbiallyderived HS. Changes in HS composition revealed that internal reservoir processes may have influenced HS quality across the reservoir. (C) 2020 Elsevier Ltd. All rights reserved.
CRIS-Team WoS Importer:2021-03-12

Multiproxy approach to understanding the origin of Cretaceous pelagic limestone-marl alternations (DSDP site 391, Blake-Bahama Basin) - Westphal, Hildegard; Munnecke, Axel; Pross, Jörg; Herrle, Jens; Munnecke, Axel; Munnecke, Axel (Sedimentology, 2004)
Limestone-marl alternations are usually directly interpreted to reflect cyclic palaeoenvironmental signals. However, uncertainty in such interpretations stems from the differential diagenesis that most limestone-marl alternations have undergone. Differential diagenesis results in markedly different alterations between limestones and marls and in the loss of comparability of many measurable parameters. For an unequivocal interpretation of the origin of rhythmic alternations, diagenetically robust parameters or parameters that clearly indicate the degree of diagenetic bias are required. The present study uses a multiproxy approach (independent biotic, sedimentary and geochemical parameters) in order to unravel the palaeoenvironmental signal recorded in Valanginian (Early Cretaceous) limestone-marl alternations from the Blake-Bahama Basin (DSDP site 391). Using this approach, terrestrial and marine influences can be distinguished, changes in nutrient levels estimated and prediagenetic differences in the non-carbonate fraction constrained. Surprisingly, no systematic variations in any of these parameters were observed between limestone and marl layers, implying that none of these was directly responsible for the formation of the rhythmic alternation. Hence, none of the current models of sedimentary formation of limestone-marl rhythmites is applicable here. Calcareous nannofossils are equally well preserved in limestone and marl layers, ruling out their dissolution in marl layers as a source of the calcite cement in the limestone beds. Sr values of 700-900 p.p.m. indicate that aragonite may have been present in the original, pelagic sediment. The assumption of fine-grained sedimentary aragonite imported from nearby carbonate platforms as the source of the cement would explain a number of otherwise enigmatic features in these rhythmites, including the source of the calcite cement observed in the limestones, the equally good preservation of calcareous nannofossils in limestones and marls and the higher concentration of calcareous nannofossils in marl layers. The study demonstrates that examination of diagenetically inert parameters or parameters in which diagenetic effects can be filtered can yield unexpected results. Clearly, careful analysis of such parameters needs to be undertaken in order to make reliable palaeoenvironmental interpretations from rhythmite successions. © 2004 International Association of Sedimentologist
Keywords: Calcareous nannofossils; Cretaceous; Differential diagenesis; DSDP; Limestone-marl alternations; Palynomorphs

Multistage fluorite mineralization in the southern Black Forest, Germany: Evidence from rare earth element (REE) geochemistry - Hintzen, Robin; Werner, Wolfgang; Hauck, Michael; Klemd, Reiner; Fischer, Lennart A. (European Journal of Mineralogy, 2023)
The Black Forest hosts a wide range of hydrothermal mineralization, including fluorite-barite vein deposits. In a detailed investigation of the Finstergrund and Tannenboden deposits in the Wieden mining district (southern Black Forest), the diversity, geochemical evolution and relative chronology of multistage fluorite precipitation is tracked on the basis of rare earth element (REE) geochemistry, geologic field relationships and crystal zoning. Geochemical discrimination and mathematical λ coefficients suggest a total of seven fluorite REE groups, at least three distinguishable post-Variscan fluid mobilization events and independent formation histories for the deposits despite their spatial proximity. Fluorite vein mineralization at the Finstergrund deposit evolved over three fluid generations, was derived from gneissic source aquifers and comprises five distinct fluorite REE groups: the first fluid generation is characterized by fluorite precipitation above 200°C ("group III"), below 200°C ("group I") and after fractional crystallization ("group IV"); the second generation comprises remobilized fluorite ("group II"); and the third generation revealed fluorite precipitation by meteoric water mixing ("group V"). Fluorite vein formation at the Tannenboden deposit is associated with two distinct fluorite REE patterns derived from the same fluid generation: fluorite precipitation above 200°C ("group VII") and after cooling below 200°C ("group VI"). Its fluid source aquifer lithology best matches migmatites contrary to previous models that suggest either gneissic or granitic aquifer rocks for fluorite vein precipitation in the Black Forest. The decoupled formation history between the deposits is tectonically controlled as suggested by a new genetic model for the Wieden mining district. The model argues for a change in the local fluid percolation network and the termination of hydrothermal activity at the Tannenboden deposit after the first fluid mobilization event. The geochemical evolution of multistage fluorite mineralization, as exemplified by the Tannenboden and Finstergrund deposits in combination with other fluorite mineralizations in the Black Forest, provides unique insights into the lithospheric origin and precipitation behaviour of fluorite by various fluid-rock interaction processes occurring in large hydrothermal systems. The local diversity of REE patterns emphasizes the need for detailed investigations of individual hydrothermal vein deposits.
CRIS-Team Scopus Importer:2023-07-21

Multistratigraphy of condensed ammonoid beds of the Rappoltstein (Berchtesgaden, Southern Germany): unravelling palaeo-environmental conditions on Hallstatt deep swells during the Reingraben Event (late Lower Carnian) - Joachimski, Michael; et al. (Facies, 2007)
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LG.multis

Multi-system geochronology of North Dabie eclogite: Ineffective garnet ‘shielding’ on rutile inclusions under multi-thermal conditions - Zhou, Tian; Li, Qiuli; Klemd, Reiner; Shi, Yonghong; Tang, Xu; Li, Chaofeng; Liu, Yu (Lithos, 2020)
It has been shown that certain host minerals can robustly shield mineral inclusions and prevent loss of petrochronological information during subsequent thermal events. Rutile inclusions in garnet may crystallize under a wide range of metamorphic conditions and thus rutile is expected to be a useful geochronometer for constraining different stages of a metamorphic P-T path. Hence, it is important to ascertain whether rutile inclusions shielded by garnet retain the original crystallization age information despite later retrograde cooling or subsequent new thermal events. In this study, we test the “shielding effect” of garnet on rutile inclusions from the Baizhangya eclogite in the North Dabie Zone (China), which underwent a multi-stage thermal evolution. Secondary ion mass spectrometry (SIMS) U[sbnd]Pb dating of inherited zircon core domains constrains a Neoproterozoic formation age ( 770 Ma) of the eclogite protolith. SIMS U[sbnd]Pb dating of metamorphic zircon and complementary thermal-ionization mass spectrometry (TIMS) Sm[sbnd]Nd isochron dating of garnet revealed Triassic eclogite-facies metamorphic ages (245–210 Ma). An Early Cretaceous SIMS U[sbnd]Pb age of ca. 130 Ma, yielded by matrix rutile grains and rutile inclusions, suggests significant isotopic alteration since crystallization. This indicates that shielding was ineffective, since the U[sbnd]Pb ages derived from the rutile inclusions, although hermetically armored by garnet, were influenced by a subsequent Early Cretaceous tectono-thermal event. Further transmission electron microscope (TEM) analysis revealed the presence of hematite microlites along the garnet-rutile boundaries, which may have acted as a potential reservoir to store the expelled radiogenic Pb from rutile. This study suggests that newly formed minerals located along mineral boundaries seem to be crucial for understanding the shielding effect.
CRIS-Team Scopus Importer:2020-06-23
Keywords: Rutile inclusions; Secondary ion mass spectrometry; Shielding effect; Transmission electron microscope; U-Pb dating

Mustelids from Sackdilling Cave (Bavaria, Germany) and their biostratigraphic significance - Marciszak, Adrian; Ambros, Dieta Carola; Hilpert, Brigitte (Geobios, 2021)
Sackdilling Cave is a karst fissure filled with a fossiliferous breccia including abundant fossil remains, mostly snails and small mammals. The taxonomic status of mustelid remains from this cave was previously regarded as controversial and, consequently, different authors listed different species from the locality. A detailed revision of the material shows the presence of five mustelid species: Meles sp., Martes vetus, Mustela strandi, Mustela palerminea, and Mustela praenivalis. Among them, especially noteworthy is the presence of the type specimen of Martes vetus. The Sackdilling holotype resembles Martes foina and differs from that of Martes martes in a short and broad viscerocranium; wide and less extended forward incisor row; compressed, short and wide temporal region; large, strongly inflated and convex tympanic bullae; and narrow P3 with weak lingual bulge. Some dental characters are specific for Martes vetus and show some intermediate values between Martes foina than Martes martes. Among them are the P4 protocone length and the M1 trigon length. The revised material from Sackdilling Cave of Mustela palerminea and Mustela praenivalis was compared with that from other Early and early Middle Pleistocene sites of Europe and showed the presence of intermediate characters. Subsequently, based on the entire mustelid assemblage and other faunal elements (mainly rodents), the age of this fauna was estimated as ca. 0.9-0.7 Ma. (C) 2021 Elsevier Masson SAS. All rights reserved.
CRIS-Team WoS Importer:2021-11-19

Mythos Drache: Schwingen, Schuppen, Schwefeldämpfe. Ein studentisches Forschungsprojekt auf Spurensuche - Link, Michael (Skeptiker, 2003)
UnivIS-Import:2015-03-09:Pub.2003.nat.dgeo.IGM.LP.mythos

Natural Attenuation investigations of an abandoned landfill contaminated by chlorinated hydrocarbons - Rüttinger, Stefan; Breiter, Roman; Hirsch, Katharina; Salaices Avila, Manuel Alejandro; Tobschall, Heinz; Neeße, Thomas; Bayer, Manfred (Grundwasser, 2006)
The Natural Attenuation of chlorinated hydrocarbons leaking from an abandoned landfill was the focus of an investigation conducted within the framework of the Bavarian joint research project "Nachhaltige Altlastenbewaltigung unter Einbeziehung des naturlichen Reinigungsvermogens". The research focused on two contaminant plumes, one having a diffuse TCE/PCE source and the other a cis-DCE source. The TCE/PCE plume had a maximum concentration of 52 mu g/l total chlorinated hydrocarbons near the source area. Cis-DCE concentrations near the source of the second plume were up to 7,000 mu g/l. In addition, degradation products (VC and Ethylene) were detected in this region, which indicate reductive dechlorination of the cis-DCE, TCE or PCE pollutants. However, other investigations indicate that the natural attenuation potential of the site is low and that the reduction in concentration is dependant more on dilution and other unknown processes. Stemming from this research, a new approach was developed using Solid Phase Micro Extraction (SPME) and GC/FID analytical techniques for microcosm testing. Furthermore, an airtight column was developed that allows the detection of sorption of highly volatile substances in low concentrations within an aquifer material.

Natürliche Gammastrahlung von Graniten in der Oberpfalz (Nordost-Bayern) – Vergleich von aerogeophysikalischen und in situ gammaspektrometrischen Messungen - Scharfenberg, Lars; de Wall, Helga (Geologische Blätter für Nordost-Bayern und angrenzende Gebiete, 2016)
Das Oberpfalz- (Tirschenreuth-) Komposit-Massiv, das östlich der Fränkischen Linie liegt, bildet einen von verschiedenen variszischen Granitkomplexen im Grenzgebiet zwischen Deutschland und der Tschechischen Republik. Granitische Gesteine bedecken etwa 450 km² der Fläche des anstehenden Grundgebirges in der Oberpfalz. Während dem kontinentalen Tiefbohrprojekt (KTB) wurde 1991 im Rahmen einer helikoptergestützten geophysikalischen Messkampagne auch eine gammaspektrometrische Erkundung in der Umgebung von Windischeschenbach durchgeführt, welche Teile der granitischen Körper im Umkreis erfasste. Rohdaten dieser Erkundungen wurden genutzt, um Differentiationsmuster für die Granite abzuschätzen. In dieser Studie wurden in situ Erkundungen mit einem tragbaren Gerät durchgeführt, um die aus den luftgestützten Messungen gewonnenen Daten am Boden zu überprüfen. Unterschiede im Wertebereich zwischen den Messungen werden diskutiert. Die Granite in der Oberpfalz zeigen klare Unterschiede in ihren Uran- und Thorium-Konzentrationen zwischen und in den zwei Intrusionskomplexen, dem Älteren Intrusionskomplex und dem Jüngeren Intrusionskomplex. Ein beeinflussender Faktor ist die Differentiation des Magmas mit einer allgemeinen Verringerung der Thorium- und einem Anstieg der Uran-Konzentrationen, was vor allem in den jüngeren Granittypen einschließlich des Steinwald- und Flossenbürg-Granits ausgeprägt ist.
Keywords: Granite; Oberpfalz; Gammastrahlung

Nb-depleted andesites from the Pacific-Antarctic Rise as analogues for early continental crust. - Haase, Karsten; Stroncik, Nicole; Hékinian, Roger; Stoffers, Peter (Geology, 2005)
Sampling of the Pacific-Antarctic Rise close to the Foundation hotspot in the South Pacific reveals that silicic lavas erupt together with basalts on a 130-km-long part of this mid-oceanic ridge, representing the most extensive occurrence of andesites on the submarine spreading system. Most of these tholeiitic andesites and dacites have negative Nb and Ta anomalies, a signature that has so far been attributed only to subduction-related magmas and the continental crust. The silicic lavas formed by fractional crystallization from basalts and assimilation of melts from hydrothermally altered amphibolite in the oceanic crust. The presence of andesites with negative Nb and Ta anomalies on the Pacific-Antarctic Rise implies that such magmas are not restricted to subduction zones but can form at a plume-influenced mid-oceanic ridge. The andesites and dacites from the Pacific-Antarctic Rise may represent analogs to some Precambrian volcanic rocks and early continental crust. © 2005 Geological Society of America.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.legeo.nbdepl
Keywords: Crust formation; Geochemistry; Mantle plume; Silicic lavas

Nb–Ta fractionation by partial melting at the titanite–rutile transition - John, Timm; Klemd, Reiner; Klemme, Stephan; Pfaender, Joerg A.; Hoffmann, J. Elis; Gao, Jun (Contributions To Mineralogy and Petrology, 2011)
During the evolution of the Earth, distinct geochemical reservoirs with different Nb/Ta ratios have developed. Archean granitoids of the tonalite-trondhjemite-granodiorite (TTG) suite, which represent the Earth's early continental crust, show larger Nb/Ta variations than any other Earth reservoir. This implies that significant Nb-Ta fractionation must have occurred during early crust formation, while the underlying mechanism behind is still unclear. Here, we present a new model on how Nb may be fractionated from Ta during partial melting of subducted oceanic crust. Our data show that Nb/Ta ratios in melts derived from rutile- and titanite-bearing eclogite are largely controlled by the modal relative abundances of rutile and titanite in the source. High modal ratios of titanite over rutile generate melts with very high Nb/Ta (>60), whereas low modal titanite/rutile produces melts with much lower Nb/Ta (≤30). Very low Nb/Ta (<16) occur when all Ti-phases are consumed at very high degrees of melting. As the modal ratio of titanite to rutile is a function of pressure, the Nb/Ta of melts is a function of melting depth. Our new model helps to explain the extreme variation of Nb/Ta observed in many TTGs and thus how Nb and Ta were fractionated during the early evolution of the Earth. Furthermore, the model also indicates that simple one-stage melting models for mafic crust are not sufficient to explain the formation of TTGs. © 2010 Springer-Verlag.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.c3geoc.nbtafr
Keywords: Crustal evolution; Eclogite; Nb-Ta; Partial melting; Rutile; Subduction zone; Titanite

Neodymium isotopes of central Mediterranean phosphatic hardgrounds reveal Miocene paleoceanography - Cornacchia, Irene; Brandano, Marco; Agostini, Samuele; Munnecke, Axel (Geology, 2022)
Understanding the causes of the formation of hardgrounds provides insights on the oceanographic evolution of a basin. Phosphate-rich hardground formation interrupted carbonate ramp deposition in the Mediterranean during the Miocene. We analyzed the epsilon(Nd) record of three central Mediterranean hardgrounds to identify the origin of the phosphate-rich waters that formed them within the frame of Mediterranean Miocene paleoceanographic evolution. The Nd isotopes suggest that eastern Mediterranean deep waters were controlled by runoff, in contrast to Atlantic and Indian Ocean waters. This Nd isotope record attests to the weakening of Mediterranean circulation during the Miocene due to closure of the Indian Gateway. Limited exchange with Atlantic shallow seawater led to long residence times for deep waters in the basin. This record indicates the role of upwelling in formation of phosphate hardgrounds and shows the influence of global climate change and local paleoceanographic conditions.
CRIS-Team WoS Importer:2022-06-24

Neon and helium isotopes as tracers of mantle reservoirs and mantle dynamics. - Stroncik, Nicole; Niedermann, Samuel; Haase, Karsten (Earth and Planetary Science Letters, 2007)
He isotopes are usually used as tracers for the identification of mantle reservoirs and mantle dynamics. High 3He/ 4He ratios are thought to represent deep mantle material, whereas ratios around 8 R A (R A stands for the atmospheric 3He/ 4He ratio of 1.39 × 10 - 6) are thought to be representative of the upper mantle. Based on He, Ne and Ar fusion data from fresh, submarine volcanic glasses of several Mid-Atlantic Ridge off-axis seamounts we show that He isotopes can be susceptible to interferences during melt formation and evolution resulting in the decoupling of He from other elements, such as e.g. Ne or Pb. All obtained He data are indistinguishable from that of the MORB range. In contrast, Ne isotopic compositions are much more primitive than MORB. Combined He, Ne and Ar systematics show that the source region of these seamounts has experienced a preferential loss of He compared to Ne and Ar. This He loss, combined with subsequent 4He production, resulted in the decoupling of the He isotope systematics from Ne and Pb. Thus, when considering He and Ne, only Ne has preserved the evidence that a primitive mantle component contributed to the formation of the investigated seamounts. As these seamounts are not fed from a mantle plume being derived from the deep mantle, the primitive Ne component resides within the upper mantle, implying that primitive noble gases are not necessarily indicative of deep mantle material. © 2007 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.legeo.neonan
Keywords: decoupling; mantle sources; mantle tracer; neon

Neoproterozoic geodynamics in NW India–evidence from Erinpura granites in the South Delhi Fold Belt - de Wall, Helga; Regelous, Anette; Schulz, Bernhard; Hahn, Gregor; Bestmann, Michel; Sharma, Kamal Kant (International Geology Review, 2021)
Erinpura Granites form the basement for the Neoproterozoic Malani Igneous Suite in NW India. Based on this study, the Erinpura granites can be divided into Erinpura-East (gneissic fabric), a belt parallel to the southern sector of the South Delhi Fold Belt, and Erinpura-West (magmatic fabrics). EPMA dating on monazites gives a time frame of 890 to 860 Ma for crystallization of both types. The geochemically homogeneous peraluminous S-type granites with εNd values of −2.1 to −10.8 are interpreted as melting products of Archaean crust. REE pattern follows the pattern of the average continental crust, but Erinpura-East samples are more fractionated with steeper HREE depletion indicating melting in a deeper crustal level. A thermal pulse between 835 and 820 Ma constrains the timing of deformation in granite-gneisses during uplift along thrust planes, coeval with shear-bound exhumation of high-grade metamorphic rocks and initiated by delamination of the lower crust in this southern sector of the South Delhi Fold Belt. This is in contrast to the northern sector of the SDFB with arrested orogenic development and without considerable delamination or erosion of the lower crust. Latest movement related to the 200 Ma tectono-magmatic history overlaps with initiation of rifting during the Malani igneous event. A change from S-type to A-type granites and shift of isotopic signatures to εNd values of −2.8 to −1.7 indicate substantial contribution of asthenospheric material in the Malani melting process.
CRIS-Team Scopus Importer:2021-06-04
Keywords: delhi orogeny; epma dating; granite petrogenesis; Neoproterozoic magmatism; sr-nd isotopes

Neptunian dykes in the Devonian carbonate buildup Aferdou El Mrakib (eastern Anti-Atlas, Morocco) and implications for its growth - Tessitore, Lorena; Naglik, Carole; de Baets, Kenneth; Galfetti, Thomas; Klug, Christian (Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, 2016)
Aferdou El Mrakib is the largest single carbonate buildup in the eastern Anti-Atlas, Morocco. Its sediments are intersected by several Neptunian dykes. Herein, we compare their facies, spatial arrangement and the associated fauna to that of Neptunian dykes from other mound localities in Morocco and elsewhere in order to assess their origin as well as that of the mound. One of the studied dykes is filled with pisoids. Its facies suggests some kind of seep origin, but the carbon and oxygen isotopic values have only slightly negative signatures, which might be diagenetic, thus prohibiting further interpretation. Nevertheless, the unique occurrence of pisoids at a depth of c. 50 metres below the mound surface within a dyke is herein interpreted as supporting the presence of a source with a considerable discharge.
Keywords: Morocco; Devonian; Maider Basin; carbonate buildups; Neptunian dykes; pisoids

Net ecosystem production in the great lakes basin and its implications for the North American missing carbon sink: A hydrologic and stable isotope approach - Karim, A.; Veizer, J.; Barth, Johannes (Global and Planetary Change, 2008)

Neuaufschluss des berühmten Schwarzjura-Profils am historischen Ludwig-Donau-Main-Kanal bei Dörlbach/Mittelfranken - Arp, Gernot; Schulbert, Christian; Seuß, Barbara; Aiglstorfer, Manuela; Havlik, Philipe; Krause, Thorsten; Waltschew, Anton; Strobl, Christian (GMIT - Geowissenschaftliche Mitteilungen, 2011)
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LP.neuauf

New analytical possibilities for monitoring the phase development during the production of autoclaved aerated concrete - Schreiner, Jürgen; Jansen, Daniel; Ectors, Dominique; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; Volkmann, Stephan (Cement and Concrete Research, 2018)
This work presents improved analytical methods for both steps of the production process of autoclaved aerated concrete (AAC), the phase development during the hydration before autoclaving and during the autoclaving process itself. The improvement includes new insights into preparation methods of AAC samples for powder diffraction as well as Rietveld refinement strategies. For the first time a new implementation for calculating anisotropic crystal domain sizes is applied to major hydrate phases occurring during AAC production, namely portlandite during the hydration before autoclaving and tobermorite during the autoclaving process. The calculation of anisotropic domain size growth, which can be implemented in the Rietveld environment, is based on crystallographically and geometrically appropriate models. The implementation of calculating anisotropic domain sizes for the Rietveld software TOPAS 5.0 allows a superior Rietveld fit and a more accurate quantification of the phase development. Additionally it enables the tracking of growth mechanism of portlandite during hydration.<br
Keywords: Calcium silicate; Hydrothermal synthesis; silicate hydrate

New biostratigraphic and chemostratigraphic data from the Chicotte Formation (Llandovery, Anticosti Island, Laurentia) compared with the Viki core (Estonia, Baltica) - Munnecke, Axel; Männik, Peep (Estonian Journal of Earth Sciences, 2009)
Due to the lack of biostratigraphically useful graptolites in the crinoidal and reefal Chicotte Formation on Anticosti Island (Québec, Canada), the precise chronostratigraphic position of the formation is not known. New stable carbon isotope and conodont data and a comparison with the detailed conodont distribution and δC development in the Viki core (Estonia) suggest an early Telychian age (Pterospathodus eopennatus to P. a. angulatus zones) for at least the lower half of the formation. This interval is characterized by a small but distinct positive excursion in δC, with peak values of + 3.2% and + 2.8% VPDB in the lowermost 10-15 m of the Chicotte Formation on Anticosti and in the Viki core, respectively.
Keywords: conodonts; stable carbon isotopes; Anticosti; Estonia; Llandovery; Telychian

New chemostratigraphic through the Middle Mulde Event interval (Silurian, Wenlock), Gotland, Sweden - Calner, Mikael; Lehnert, Oliver; Jeppsson, Lennart (Gff, 2012)
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.newche

New constraints on the last aragonite-calcite sea transition from early Jurassic ooids - Vulpius, Sara; Kießling, Wolfgang (Facies, 2018)
Calcite and aragonite seas are commonly distinguished based on the prevailing primary mineralogy of ooids and carbonate cements over time. Secular oscillations of these seas are usually attributed to changes in ocean chemistry and paleoclimate. While the veracity of such oscillations has been verified by independent data and modeling approaches, the timing of the transition from one ocean state to the other remains poorly resolved. Here, the timing of the last aragonite-calcite sea transition is estimated by assessing the preservation of Early Jurassic ooids from the Trento Platform in northern Italy. Point counting of ooid-bearing limestones from four distinct stratigraphic levels provides a contrasting pattern: Hettangian and Sinemurian ooids are all poorly preserved and were probably predominantly originally aragonitic, whereas Pliensbachian and Toarcian ooids are excellently preserved, suggesting a primary calcitic mineralogy. Although calcitic ooids may have already been common in the Late Triassic, it is proposed that the last aragonite-calcite sea transition occurred in the Early Jurassic between the Sinemurian and Pliensbachian, at least in this subtropical region. Therefore, the selective extinction of aragonite-secreting organisms at the end-Triassic mass extinction cannot be attributed to secular changes in ocean chemistry.
Keywords: Ooid; Calcite; Aragonite; Lower to Middle Jurassic; Italy; Northern Alps

New evidence for an old idea: Geochronological constraints for a paired metamorphic belt in the central European Variscides - Will, T. M.; Schmädicke, Esther; Ling, X. -X.; Li, X. -H.; Li, Q-L. (Lithos, 2018)
Keywords: Odenwald-Spessart basement; Paired metamorphic belt; Lu-Hf isotope data; U-Pb geochronology; Variscan orogeny

New excavations at the HWK EE site: Archaeology, paleoenvironment and site formation processes during late Oldowan times at Olduvai Gorge, Tanzania - de la Torre, Ignacio; Albert, Rosa M.; Arroyo, Adrián; Macphail, Richard; McHenry, Lindsay J.; Mora, Rafael; Njau, Jackson K.; Pante, Michael C.; Rivera-Rondón, Carlos A.; Rodríguez-Cintas, Ágata; Stanistreet, Ian G.; Stollhofen, Harald; et al. (Journal of Human Evolution, 2017)
his paper reports the results of renewed fieldwork at the HWK EE site (Olduvai Gorge, Tanzania). HWK EE is positioned across the boundary between Lower and Middle Bed II, a crucial interval for studying the emergence of the Acheulean at Olduvai Gorge. Our excavations at HWK EE have produced one of the largest collections of fossils and artefacts from any Oldowan site, distributed across several archaeological units and a large excavation surface in four separate trenches that can be stratigraphically correlated. Here we present the main stratigraphic and archaeological units and discuss site formation processes. Results show a great density of fossils and stone tools vertically through two stratigraphic intervals (Lemuta and Lower Augitic Sandstone) and laterally across an area of around 300 m2, and highlight the confluence of biotic and abiotic agents in the formation of the assemblage. The large size and diversity of the assemblage, as well as its good preservation, qualify HWK EE as a reference site for the study of the late Oldowan at Olduvai Gorge and elsewhere in Africa. In addition, the description of the stratigraphic and archaeological sequence of HWK EE presented in this paper constitutes the foundation for further studies on hominin behavior and paleoecology in Lower and Middle Bed II.
Keywords: Early Pleistocene; Early Stone Age; Oldowan-Acheulean transition; Paleoecology; Spatial analysis; Taphonomy

New excavations in the MNK Skull site, and the last appearance of the Oldowan and Homo habilis at Olduvai Gorge, Tanzania - de la Torre, Ignacio; Benito-Calvo, Alfonso; Martín-Ramos, Carmen; McHenry, Lindsay J.; Mora, Rafael; Njau, Jackson K.; Pante, Michael C.; Stanistreet, Ian G.; Stollhofen, Harald (Journal of Anthropological Archaeology, 2021)
MNK Skull is one of the most significant archaeological sites in Olduvai Gorge, particularly due to the previous discovery of human fossils referred to in the paper where the Homo habilis taxon was originally defined. An important archaeological assemblage is contained in the same horizon as the hominin fossils, constituting the last evidence of both Homo habilis remains and handaxe-free tool kits in the Olduvai Gorge sequence. Our excavations at the site are the first to be conducted since the original work in the 1960s, and sought to refine the archaeological context wherein the Homo habilis remains were discovered. Chronostratigraphic results place the MNK Skull sequence in Middle Bed II prior to deposition of Tuff IIB. The assemblage was deposited near the shoreline, as Palaeolake Olduvai withdrew into the basinal depocentre, and fossils and stone tools were subjected to significant post-depositional processes. The assemblage was affected by mudflow deposits that buried and preserved the assemblage but also entrained surficial bone and lithic elements into the flow. Rather than an occupation site as originally interpreted, the assemblage is better understood as a background deposit, possibly accumulated on an unconformity surface over a long period of time. The stone tool assemblage is typical of the Oldowan, with no technological elements announcing the appearance of the Acheulean, which is well attested to across the Olduvai sequence in post-Tuff IIB times. Our results highlight that, with an approximate age of circa 1.67 Ma, MNK Skull stands as a key site to understand the late Oldowan and the disappearance of Homo habilis in East Africa.
CRIS-Team Scopus Importer:2021-01-15
Keywords: Acheulean Origins; Early Homo; Early Stone Age; Lower Pleistocene

New exposure of the Ludwigskanal section near Dorlbach - a key section for the Lower Jurassic in the Franconian Alb, Southern Germany - Arp, Gernot; Aiglstorfer, Manuela; Havlik, Philipe; Krause, Thorsten; Schulbert, Christian; Seppelt, Stephan (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 2014)
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LP.newexp

New geophysical knowledge of groundwater systems in complex estuarine environment - Di Sipio, Eloisa; Galgaro, Antonio; Zuppi, Gian Maria (Estuarine Coastal and Shelf Science, 2006)
Keywords: groundwater; salinization; Vertical Electrical Sounding; geochemistry; Venice Lagoon 1. Introduction The south sector of the Venice Lagoon mainland is bordered by the Venice Lagoon itself to the North; by the Adriatic Sea to the East and; for about 20 km; by the Adige River to the South; (Fig. 1). The land surface has been reclaimed from the lagoon and is subject to artificial pumping. Subsidence; due to human activities and natural processes; is a phenomenon present in the area (Benvenuti et al.; 1972; Carbognin et al.; 1997; Galgaro et al.; 2000; Ciavola et al.; 2002; Brambati et al.; 2003; Carbognin and Tosi; 2003; Comerlati et al.; 2004). The high electrical conductivity (EC) values detected in the surface water and shallow groundwater point to the existence of salt intrusion. Sea tidal oscillations and anthropic

New Insights Into Application Relevant Properties of Cu2+-Doped Brushite Cements - Späth, Karla; Nawaz, Qaisar; Schilling, Tatjana; Götz-Neunhoeffer, Friedlinde; Detsch, Rainer; Boccaccini, Aldo R.; Hurle, Katrin (Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2024)
Doping of brushite cements with metal ions can entail many positive effects on biological and physicochemical properties. Cu2+ ions are known to exhibit antibacterial properties and can additionally have different positive effects on cells as trace elements, whereas high Cu2+ concentrations are cytotoxic. For therapeutical applications of bone cement, a combination of good biocompatibility and sufficient mechanical properties is required. Therefore, the aim of this study was to investigate different physicochemical and biological aspects, relevant for application, of a brushite cement with Cu2+-doped β-tricalcium phosphate, monocalcium phosphate monohydrate and phytic acid as setting retarder. Additionally, the ion release was compared with a cement with citric acid as setting retarder. The investigated cements showed good injectability coefficients, as well as compressive strength values sufficient for application. Furthermore, no antibacterial effects were detected irrespective of the Cu2+ concentration or the bacterial strain. The cell experiments with eluate samples showed that the viability of MC3T3-E1 cells tended to decrease with increasing Cu2+ concentration in the cement. It is suggested that these biological responses are caused by the difference in the Cu2+ release from the hardened cement depending on the solvent medium. Furthermore, the cements showed a steady release of Cu2+ ions to a lesser extent in comparison with a cement with citric acid as setting retarder, where a burst release of Cu2+ was observed. In conclusion, despite the anticipated antibacterial effect of Cu2+-doped cements was lacking and mammalian cell viability was slightly affected, Cu2+-concentrations maintained the physicochemical properties as well as the compressive strength of cements and the slow ion release from cements produced with phytic acid is considered advantageous compared to citric acid-based formulations.
CRIS-Team Scopus Importer:2024-09-13
Keywords: antibacterial properties; copper; cytotoxicity; ion doping; β-tricalcium phosphate

New insights into the crystallization process of sol-gel–derived 45S5 bioactive glass - Nawaz, Qaisar; de Pablos-Martín, Araceli; Martins de Souza e Silva, Juliana; Hurle, Katrin; Jaimes, Altair T.Contreras; Brauer, Delia S.; Boccaccini, Aldo R. (Journal of the American Ceramic Society, 2020)
In this work the influence of thermal treatment conditions was evaluated in a sol-gel-derived 45S5 bioactive glass using DSC, XRD, TEM, EDX, and X-ray nanocomputed tomography (nano-CT). Temperature and time of the thermal treatment strongly influence the composition of the crystalline phases. At the onset of the glass transition temperature (600°C), combeite crystallizes as the main phase along with a calcium silicate-phosphate phase, which decomposes into rhenanite from 2 hours of thermal treatment at this temperature. At the crystallization temperature (700°C), combeite remains as the main crystalline phase. Additionally, Na2Ca2Si2O7 crystalline phase is formed. Our results provide a basic platform for tailoring the crystalline phases by controlling the nucleation and growth of crystalline phases via thermal treatments. Different morphologies (round particles, stacked layers, toothpick-like, and long features) were discerned by TEM as a function of temperature and time of treatment. It is the first time that bioactive glass is investigated by X-ray nanocomputed tomography (nano-CT) at laboratory scale. This novel technique enables the 3D visualization of features in the nanometer range, giving a suggestion of the distribution in the sample of the parts composing the sample.
CRIS-Team Scopus Importer:2020-05-02
Keywords: bioactive glasses; crystallization behavior; Sol-gel

Newly developed Sr-substituted alpha-TCP bone cements - Pina, Sandra; Torres, Paula M. C.; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; da Fonte Ferreira, José Maria (Acta Biomaterialia, 2010)
New bone cements made of Sr-substituted brushite-forming α-tricalcium phosphate (α-TCP) were prepared and characterized in the present work. The quantitative phase analysis and structural refinement of the starting powders and of hardened cements were performed by X-ray powder diffraction and the Rietveld refinement technique. Isothermal calorimetry along with setting time analysis allowed a precise tracing of the setting process of the pastes. The pastes showed exothermic reactions within the first 10-15 min after mixing and further release of heat after about 1 h. An apatitic phase formed upon immersion of the hardened cements in simulated body fluid for 15 and 30 days due to the conversion of brushite into apatite confirming their in vitro mineralization capability. The compressive strength of the wet cement specimens decreased with increasing curing time, being higher in the case of Sr-substituted CPC. The results suggest that the newly developed Sr-substituted brushite-forming α-TCP cements show promise for uses in orthopaedic and trauma surgery such as in filling bone defects. © 2009 Acta Materialia Inc.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LM.newlyd
Keywords: Bone cement; Brushite; Rietveld refinement; Strontium; XRD

New magmatic record of Indian continental subduction at ca. 50 Ma: Evidence from ultrapotassic–potassic lamprophyre dikes in the Gangdese Batholith, Southern Tibet - Deng, Yulin; Lang, Xinghai; Klemd, Reiner; Wang, Xuhui; Tang, Juxing; He, Qing; Zhou, You; Zuo, Yinhui; Tang, Xiaoqian; Zunzhu, Sangmu (Lithos, 2025)
Geophysical and geochemical evidence confirmed the northward-directed Indian continental lithosphere subduction beneath the Gangdese orogen, however, the geodynamic processes responsible for the transition from the Neo-Tethyan subduction to the Indian continental subduction, particularly magma generation mechanisms regarding the 53–42 Ma magmatic flare-up events, remain poorly constrained. Here we have conducted a comprehensive investigation combining geochemical and geochronological studies of newly discovered Early Eocene (ca. 50–47 Ma) ultrapotassic–potassic lamprophyre dikes in the Lhasa terrane, Tibet. The ultrapotassic lamprophyres revealed highly evolved Sr–Nd–Pb isotopes and high concentrations of incompatible elements, and are thought to have originated from the Indian lithospheric mantle. In contrast, the potassic lamprophyres, displaying relatively depleted Sr–Nd–Pb isotopes and lower MgO contents and K2O/Na2O ratios than the ultrapotassic lamprophyres, show high Sr/Y and low Y geochemical signatures, thereby demonstrating that they formed due to contamination of the ultrapotassic lamprophyre magma by adakitic melts. We, therefore, propose that the lamprophyres represent a new magmatic record of the Indian lithosphere, suggesting that the subduction of Indian plate beneath the Lhasa terrane was already operating at ca. 50 Ma. The data gained here in conjunction with published data further suggest that the upwelling asthenosphere associated with the Neo-Tethyan slab breakoff caused the significant melting of both mantle and crust.
CRIS-Team Scopus Importer:2025-01-31
Keywords: Indian continental subduction; Lhasa terrane; Slab breakoff; Ultrapotassic-potassic lamprophyre dikes

New monofunctional platinum(II) and palladium(II) complexes: Studies of the nucleophilic substitution reactions, DNA/BSA interaction, and cytotoxic activity - Cocic, Dugan; Jovanovic, Snaana; Radisavljevic, Snezana; Korzekwa, Jana; Scheurer, Andreas; Puchta, Ralph; Baskic, Dejan; Todorovic, Danijela; Popovic, Suzana; Matic, Sanja; Petrovic, Biljana (Journal of Inorganic Biochemistry, 2018)
Keywords: Kinetics; DNA; DFT; Cytotoxicity; Pd(II) and Pt(II) complexes; BSA

New Oldowan localities at high level within Kilombe Caldera, Kenya De nouvelles localités oldowayennes à un niveau élevé dans la caldeira de Kilombe, au Kenya - Gowlett, John A.J.; Stanistreet, Ian G.; Albert, Rosa M.; Blackbird, Sabena J.; Herries, Andy I.R.; Hoare, Sally; Kogai, Philip; Komboh, Caroline K.; Mark, Darren F.; Muriuki, Rebecca M.; Murphy, Hayley; Rucina, Stephen M.; et al. (Anthropologie, 2022)
New occurrences of early artefacts ascribed to the Oldowan tradition come from localities at high level within the caldera of the extinct Kilombe volcano, located in the central rift valley of Kenya. The trachyte cone and caldera of Kilombe volcano formed at ca. 2.5 Ma, and the record of >130 m of sediment-fill indicates that the caldera subsequently held a lake for long periods during the Early Pleistocene. The Oldowan artefact localities, dated by 40Ar/39Ar and palaeomagnetism to ∼1.78 Ma, lie east of the centre of the caldera, on the west side of an ancient small lake, which later drained away as a gorge formed on the east side of the mountain. The artefacts are dominantly made of Kilombe trachyte, and are associated with a fauna of large animals including Hippopotamus gorgops. These are the first Oldowan localities to be discovered in a new area of the Kenyan rift valley in the last thirty years, and their presence at high level in rugged landscape indicates that the associated hominins were exploiting a full range of environments.
CRIS-Team Scopus Importer:2022-02-25
Keywords: Argon-Argon (; Caldera; Oldowan; Rift Valley high-altitude

New Olduvai Basin stratigraphy and stratigraphic concepts revealed by OGCP cores into the Palaeolake Olduvai depocentre, Tanzania - Stanistreet, Ian G.; Stollhofen, Harald; Deino, Alan L.; McHenry, Lindsay J.; Toth, Nicholas P.; Schick, Kathy A.; Njau, Jackson K. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2020)
The Olduvai Gorge Coring Project (OGCP) drilled four boreholes 1A, 2A, 3A, 3B at three sites into the central palaeolake of the Olduvai Basin depocentre. Previously known Beds I, II, III, IV, Masek Beds and Ndutu are identifiable in the upper part of the cores, and from these formations predominantly lacustrine facies associations are recognised. These are described and then interpreted in terms of their palaeoenvironmental significance. However, stratigraphy known from natural outcrop exposures is more than doubled by strata intersected below. For example, an extra 135 m of pre-Bed I stratigraphy in Core 2A records the entire volcanic history of a fan-delta sourced from Ngorongoro Volcano. Beneath that fan sequence is an interval of fluvio-lacustrine non-volcaniclastic sediments. For the latter the new stratigraphic term Naibor Soit Formation is introduced, because these strata were discovered for the first time in Boreholes 2A and 3A, to either side of Naibor Soit Inselberg, where they thus lap onto its basement topography. The volcanically sourced unit above is named Ngorongoro Formation, including Marker Tuffs CFCT (Coarse Feldspar Crystal Tuff) and the Naabi Ignimbrite within its topmost portion. Only the dominantly lacustrine sediments above the main Ngorongoro sourced fan body are now attributed to Lower Bed I. The Ngorongoro Formation defined here contains primary Tuff Markers NgA to NgQ, and volcaniclastic fan-delta deposits that interfinger with and overlie claystones and interbedded sandstones of the fluvio-lacustrine Naibor Soit Formation. Boreholes 1A and 2A intersect the Bed I Basalt, but not Borehole 3A, where the position of the lava is marked by three separated volcaniclastic sandstone layers, containing pebble-sized basalt scoriae, likely correlating to three complex basalt flows at Locality 9A and Orkeri and allowing assessment of syn-basalt sedimentation. Disconformities bounding Beds I, II, III, IV, Masek Beds and Ndutu Beds provide important stratigraphic markers for the novel application of sequence stratigraphic concepts, as they mark lowstands of Palaeolake Olduvai, guiding outcrop to core correlations. Major disconformities are identified in: (1) Core 1A, where the Lower Bed II Crocodile Valley Incision Surface cuts out Tuff IF; (2) Core 1A, where disconformities and facies within Beds II, III, IV, and Masek Beds are identified; (3) Cores 2A and 3A, where Tuff IF is identified below the Lower to Middle Bed II disconformity; and (4) Lower Bed I claystones and Tuff IA in Core 3A that correlate to similar sedimentary units from Locality 66e in the Western Gorge, but which are absent from Core 2A because of a newly identified major disconformity, which causes the Bed I lava to sit directly on top of the CFCT marker.
CRIS-Team Scopus Importer:2020-06-23
Keywords: Borehole core; Disconformity; Naibor Soit Formation; Ngorongoro Formation; Olduvai Beds

New Ordovician-Silurian drill cores from the Siljan impact structure in central Sweden - an integral part of the Swedish Deep Drilling Program - Lehnert, Oliver; Meinhold, Guido; Bergström, Stig M.; Calner, Mikael; Ebbestad, Jan Ove; Egenhoff, Sven; Frisk, Asa; Hannah, Judith L.; Högström, Annette E. S.; Huff, Warren D.; Juhlin, Christopher; Maletz, Jörg; et al. (Gff, 2012)
New drill cores from the largest known impact structure in Europe, the relict of the Siljan meteorite crater, provide new possibilities to reconstruct Early Palaeozoic marine environments and ecosystems, and to document changes in sedimentary facies, sea level and palaeoclimate in Baltoscandia. The impact crater is an important target of the project "Concentric Impact Structures in the Palaeozoic" within the framework of the "Swedish Deep Drilling Program". Two core sections, Mora 001 and Solberga 1, have been analysed. The sedimentary successions of these core sections include strata of late Tremadocian through late Wenlock ages. Our preliminary studies show not only that several of the classical Palaeozoic units of Sweden are represented in the area, but also that other significantly different facies are preserved in the Siljan district. An erosional unconformity representing a substantial hiatus occurs between Middle Ordovician limestone and a Llandovery-Wenlock (Silurian) shale succession in the western part of the Siljan structure and suggests an extended period of uplift and erosion. This may be related to forebulge migration due to flexural loading by the Caledonian thrust sheet to the west. Thus, this part of Sweden, previously regarded as a stable cratonic area, presumably was affected by the Caledonian collision between Baltica and Laurentia. © 2012 Copyright Geologiska Föreningen.
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.neword
Keywords: impact structure; Ordovician; Siljan district; Silurian; stratigraphy; Sweden

New Permian-Triassic conodont data from Selong (Tibet) and the youngest occurrence of Vjalovognathus - Wang, Lina; Wignall, Paul B.; Sun, Yadong; Yan, Chunbo; Zhang, Zaitian; Lai, Xulong (Journal of Asian Earth Sciences, 2017)
Keywords: Biostratigraphic correlation; Himalaya; Induan; Mass extinction; Vjalovognathus

New radiolarians from the earliest Cretaceous of the Sultanate of Oman (Wahrah Formation, Jebel Buwaydah) - Kießling, Wolfgang (Palaeontologische Zeitschrift, 1995)

New radiometric datings of different cave bear sites in Germany - results and interpretations - Rosendahl, Wilfried; Döppes, Doris; Joger, Ulrich; Laskowski, Rainer; López Correa, Matthias; Nielbock, Ralf; Wrede, Volker (Bulletin de la Société d'histoire naturelle de Toulouse, 2005)
New radiometric dates from seven cave bear sites in Germany were achieved during the last two years. The dates were obtained for four sites from bone samples, for one site from two stalagmites and from another site from charcoal and bones. The bones and the charcoal have been dated with the AMS 14C-method and the stalagmites with the TIMS-U/Th-method. Sites are briefly described and all dates with their analytic values are presented and discussed in methodological and paleoclimatic context. Radiocarbon ages were calibrated using calPal2004 (www.calPal.de) and paleoclimatic interpretation was made by correlation with the GISP2 ice core δ18O-curve (Stuiver & Grootes, 2000), GI = Greenland Interstadial of the GIPS2 ice core.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LP.newrad
Keywords: cave bear

New records of early Middle Jurassic belemnites in the French Subalpine Basin and their paleobiogeographic significance - Mariotti, Nino; Weis, Robert; di Cencio, Andrea; Clément, Arnaud; de Baets, Kenneth (Geobios, 2012)
A biostratigraphic and systematic study based on belemnites collected along with ammonites was performed on four sections in the Subalpine Basin (SE France): Lac du Castillon and La Baurne (Castellane area), Galabrun and Grand Lara (Gap area). The specimens, originating from hemi-pelagic marllimestone alternations in the lower part of the "Calcaires a Zoophycos" Formation, are dated from Middle Aalenian (Murchisonae Zone) to Lower Bajocian (Humphriesianum Zone). Five belemnite taxa (Megateuthis elliptica, Holcobelus munieri, H. trauthi, Pachybelemnopsis roettingensis, Hibolithes sp.) have been identified, and two more taxa are reported in an open nomenclature (Belemnitida incertae sedis sp. 1 and sp. 2). The biostratigraphic range of the belemnite fauna is established. The new findings contribute to a more detailed understanding of the paleobiogeography of holcobelid belemnites that flourished at the northern margin of the Tethys Ocean and formed a distinct sub-Mediterranean fauna. The association herein described is similar to the fauna of the Calabro-Peloritani Arc (Calabria, Italy), a further hint for the supposed paleogeographic position of the latter during the Middle Jurassic. (C) 2012 Elsevier Masson SAS. All rights reserved.
Keywords: Holcobelidae; Megateuthididae; Mesohibolithidae; Middle Jurassic; Subalpine Basin; Biostratigraphy; Paleobiogeography

New SEM observations of keriothecal walls: Implications for the evolution of fusulinida - Vachard, Daniel; Munnecke, Axel; Servais, Thomas; Munnecke, Axel; Munnecke, Axel (Journal of Foraminiferal Research, 2004)
This study presents new scanning electron microscopy (SEM) observations of Paleozoic foraminifera. It focuses especially on the wall of three Fusulinida, Sakmarella moelleri, Paraskinnerella skinneri, and Taiyuanella furoni, that belong to the Schwagerinoidea, which are fusulinids with keriothecal test walls. In addition, Eostaffella sp. is investigated as an example of the microstructure of the microgranular imperforate tectum. The fillings of the keriothecal alveoles of Sakmarella, Paraskinnerella, and Taiyuanella yield diverse, characteristic flower-like structures that indicate a gradual evolution of the microstucture of the tests. Sakmarella and Paraskinnerella have flowers with a narrow center, and Taiyuanella has a larger center. The true keriothecal structure, described, for example, in Triticites, is distinguished from these structures by simply filled alveoles. The term "anthotheca" is introduced for the structure with narrow-centered flowers. It can be distinguished from the large-centered flower structure identified as Zhuang's (1989) stalactotheca. Following a literature review of previous work on keriothecal structures, several morphofunctional hypotheses are discussed, including the housing of symbiotic algae or cyanobacteria, which leads to the new interpretation that the flowers of the antho- and stalactothecal structures are induced by algal endosymbionts. In addition, we discuss the monophyly of keriothecal fusulinids. The transition from diaphanothecal to keriothecal forms recognized since Thompson (1964) is reinterpreted in terms of relationships with symbiotic algae or cyanobacteria. The Schwagerinoidea constitute an important group in understanding the evolution of larger foraminifera in the late Paleozoic.

New thermophysical data pool for NE-Bavaria reveals exceptionally high heat fluxes - Kämmlein, Marion; Bauer, Wolfgang; Stollhofen, Harald (German Geothermal Congress GGC 2017, 2017)
A geothermal anomaly in the Franconian Basin/NE Bavaria was already described in the 1980s and further specified in the 2000s. An undisturbed temperature log in a 1309 m deep well provided a geothermal gradient (gradT) of 4.8 K/100m. The enhanced geothermal gradients led to the development of several balneological facilities in the area. However, heat flux in the Franconian Basin has never been quantified. Only supra-regional heat flux densities for the Rhenohercynian and Saxothuringian of 65 – 85 mW/m2 were published, based on a few temperature data only from 50 – 300 m depths and literature derived thermal conductivity values. Within the framework of a study on the geothermal potential of NE Bavaria, a new dataset of statistically evident thermo-physical parameters of almost all stratigraphic units of the up to >1600 m thick sedimentary cover rocks of NE Bavaria was created. The newly established data pool comprises measurements of 932 core samples, 661 plug samples and 57 rock fragment samples. Thermal conductivity measurements were performed on dry and water saturated core samples and powder samples from rock fragments. For the determination of gradT, available temperature logs and BHT data of deep wells in NE Bavaria were evaluated. Temperature data were derived from log sections, which are not influenced by artesian upflow. For BHT correction different methods were tested. Heat flux density calculations were performed by the interval method, which is considering the thicknesses of the individual stratigraphic units and their key parameters. In total, temperature data of ten deep wells >500 m in the Franconian Basin were evaluated. Nine of these wells, which are located within the Basin, provide moderate to significantly enhanced geothermal gradients of 3.4 – 4.8 K/100m. Two of these wells do show enhanced gradT in the basement rocks. In contrast, one well at the outer edge of the basin and near the Franconian Line provides a below-normal gradT of 2.5 K/100m. By applying temperature corrected measured thermal conductivities and corrected underground temperatures, the area reveals significantly enhanced heat flux densities between 92 to 128 mW/m2. The deep well with the highest geothermal gradient of 4.8 K/100m provides heat flux densities of 128 mW/m2. The value distribution of heat flux density and geothermal gradients points to a local positive temperature anomaly within an area of about 80 x 50 km. The calculated heat flux densities lie in the order of magnitude of heat flux densities known from the Upper Rhine Rift, which provides heat flux densities around 110 mW/m2 and within the range of heat fluxes of other rift zones worldwide. The exceptionally high heat flux density value of 128 mW/m2 in the centre is based on an undisturbed temperature log which was measured 567 d after the shutdown of the drilling. This time after circulation is sufficient for thermal equilibrium in the borehole. The enhanced gradT in basement rocks of two wells points to a convective thermal regime, the heat source of which is most probably located in the deeper crust. Results of gravimetric modelling in the area, suggest the presence of local granite bodies within the basement rocks and calculations of radiogenic heat production of granitic outcrop analogues shows them sufficient to explain the enhanced gradT in the area.
Keywords: heat flux density; NE-Bavaria; thermal conductivity; thermophysical rock properties

New Tools to Support the Designing of Efficient and Reliable Ground Source Heat Exchangers: The Cheap-GSHPs Databases and Maps - Galgaro, Antonio; Dalla Santa, Giorgia; de Carli, Michele; Emmi, Giuseppe; Bertermann, David; Müller, Johannes; Castelruiz Aguirre, Amaia; Perego, Rodolfo; Pera, Sebastian; Mezzasalma, Giulia; Bernardi, Adriana (Geophysical Research Abstracts Vol. 21, EGU2019-17924, 2019, 2019)
The overall goal of the EU funded project CHEAP-GSHPs is the development of more efficient and safe shallow geothermal systems for building conditioning, and the reduction of their installation costs. New types of heat exchangers and installation techniques have been studied. In addition, in order to reduce the engineering costs of geothermal heat exchangers sizing, a Decision Support System (DSS) has been developed for the design of new geothermal systems. The DSS tools consider all aspects from the geological and drilling issues to the technical and economical ones, by starting from several possible design and operational solutions. They support the user in the selection of the most suitable heat exchanger, in the borehole field sizing and in the choice of the best installation technique. These tools are public and available on the web (http://cheap-gshp.eu/); they have been targeted at users with different levels of knowledge, so that they can be used by both expert and non-expert users. Several databases have been built up to feed the DSS: (I) a detailed Thermo-Geological Database indicating the thermo-physical parameters of a wide spectrum of european lithologies and unconsolidated sediments classes; in order to allow the correct evaluation of the heat exchange capacity of the subsoil where a new borehole field has to be installed. (II) an European Superficial Geological Map, that represents the variability of the subsoil conditions in Europe; this is used associated to the Thermo-Geological database as well as to suggest the best drilling technique for the local geological setting; (III) a pan-european Climatic Database; (IV) a standard temporal profiles database of the heating and cooling requirements for several standardized typologies of buildings, by taking into account also several thermal insulation levels. The detailed Thermo-Geological database has been built in order to identify the most appropriate values of physical and thermal parameters to be assigned to the local geological context. The database consolidates a wide amount of data present in the international guidelines and scientific literature (it is based on more than 60 references) integrated with more than 400 experimental measurements performed on samples of rocks and sediments sampled in several european countries. The Database include 29 categories of rocks and 10 classes of unconsolidated sediments. The Thermo-Geological Database merges the thermal conductivity ranges exposed in literature with the values acquired by the direct measurements; in addition, the reference values of density and thermal diffusivity for each category are indicated. Finally, a method to map the techno-economic potential of closed-loop shallow geothermal systems (expressed as €/kW) has been developed. It merges all geological, climatic and energetic data collected in the Databases in order to quantify the geothermal potential for different locations and the feasibility of shallow geothermal systems. The method has been successfully applied in some test sites representative of main European contexts. The new web tools and the developed mapping method support the design and the installation of new shallow geothermal systems, by taking into account all the involved aspects from the geological to the economical ones. <br

New tools to support the designing of efficient and reliable ground source heat exchangers: the Cheap-GSHPs databases and maps - Galgaro, Antonio; Della Santa, Giorgia; de Carli, Michele; Emmi, Giuseppe; Zarrella, Angelo; Müller, Johannes; Bertermann, David; Castelruiz Aguirre, Amaia; Noyé, Sarah; Perego, Rodolfo; Pera, Sebastian; Poletto, Fabio; et al. (Advances in Geosciences, 2019)

Noble guests in organic cages–encapsulation of noble gases by cryptophane - Ćoćić, Dušan; Puchta, Ralph; van Eldik, Rudi (Journal of Coordination Chemistry, 2020)
With the application of DFT calculations (ωB97XD/def2-SVP/SVPfit), the ability and mechanism of noble gas encapsulation by cryptophane was investigated. Based on the applied model reaction, by monitoring geometric changes and investigating the non-covalent interactions between the studied hosts and the noble gases, the size of the host did not necessarily play a decisive role in the selective encapsulation of the guests. Rather the adjustment of the host’s interior and functionalization of its “gates” can be significant in tuning the affinity of cryptophanes.
CRIS-Team Scopus Importer:2020-10-02
Keywords: cryptophane; DFT; host-guest chemistry; Noble gases

No (Cambrian) explosion and no (Ordovician) event: A single long-term radiation in the early Palaeozoic - Servais, Thomas; Cascales-Miñana, Borja; Harper, David A.T.; Lefebvre, Bertrand; Munnecke, Axel; Wang, Wenhui; Zhang, Yuandong (Palaeogeography, Palaeoclimatology, Palaeoecology, 2023)
The Cambrian ‘Explosion’, located by many authors between 540 and 520 million years ago (Ma), is considered to be an abrupt appearance in the fossil record of most animal phyla, with a sudden increase of complex morphologies across metazoan groups. In a few recent papers, the Great Ordovician Biodiversification ‘Event’ (GOBE) has similarly been restricted to a single dramatic biodiversification ‘event’ in the Darriwilian Stage of the Middle Ordovician Series, between 470 and 455 Ma, although historically the biodiversification is considered as an aggregation of radiation ‘events’ capturing a large and complex increase of taxonomic diversity of marine invertebrates covering the entire Ordovician. A review of biodiversity curves of marine organisms during the early Palaeozoic, including some based on data in the Paleobiology Database (PBDB) and the Geobiodiversity Database (GBDB), points towards a single, large-scale, long-term early Palaeozoic radiation of life that already started in the late Precambrian. An abrupt ‘explosion’ of diversity in the Cambrian or a significant ‘event’ in the Ordovician are not visible in our biodiversity studies, because they are either regional, or only reflect a single group of organisms. It is evident that the datasets remain incomplete, in particular those for many geographical areas and for several fossil groups, that are not covered by the PBDB and GBDB; also, such areas remain so far poorly or entirely unstudied. Some recently published biodiversity curves have to be considered with care, as the truly global diversity estimates of marine organisms during the early Palaeozoic remain elusive. Here, we argue that published curves of taxonomic richness, which show distinct periods of diversification, cannot sufficiently be disentangled from biases. We therefore question the existence of a distinct Cambrian ‘Explosion’ and global Ordovician ‘Event’ in the global datasets. Both terms, Cambrian ‘Explosion’ and Great Ordovician Biodiversification ‘Event should be used as conceptional terms only. The first represents the appearance of almost all animal phyla during the late Precambrian and early Cambrian, whereas the second term embraces the numerous and complex radiations that occurred during the entire Ordovician.
CRIS-Team Scopus Importer:2023-05-26
Keywords: Biodiversity; Cambrian Explosion; Geobiodiversity Database; Great Ordovician Biodiversification Event; Paleobiology Database; Radiation

No chemical change during high-T dehydration and re-hydration reactions: Constraints from Erzgebirge HP and UHP eclogite - Schmädicke, Esther; Will, Thomas M. (Lithos, 2021)
Meta-basaltic eclogite occurs in the Erzgebirge in three high-pressure (HP) units (Unit 1, 2, and 3) as numerous lenses within high-grade felsic rocks. Units 2 and 3 are common HP units with quartz eclogite, and Unit 1 is an ultra-high pressure (UHP) unit with coesite eclogite, garnetite (metarodingite) and garnet peridotite. The conditions of peak metamorphism increase from Unit 3 (600–650 °C, 20–22 kbar), to Unit 2 (670–730 °C, 24–26 kbar) and Unit 1 (840–920 °C, ≥30 kbar), correlating with a decreasing abundance of hydrous minerals (from >10 vol% in Unit 3 to 0 vol% in Unit 1). In all units, the dominating eclogite type is dark-colored with a composition typical of MORB. A subordinate light type is chemically more variable and has higher contents of Mg, Al, Ca, Cr, Ni, and large ion lithophile elements as well as lower Fe, Zr, Y, and rare earth element concentrations than dark eclogite. Light eclogite formation is interpreted by plagioclase accumulation in a MOR magma chamber. No compositional difference is visible between well-preserved eclogite and samples with variable degrees of post-eclogitic overprint. In addition, dark eclogite from all units is compositionally indistinguishable, implying that prograde dehydration reactions did not modify major and trace element concentrations. This conclusion applies to all reactions in the temperature interval between c. 600 °C (peak T in Unit 3) and c. 900 °C (peak T in Unit 1), including prograde breakdown of calcic amphibole, zoisite, paragonite, and phengite. Together with previous studies on dehydration reactions in blueschist and eclogite at <600 °C (Spandler et al., 2003; Spandler et al., 2004), the present results imply that de-volatilization of the basaltic portion of subducting slabs plays only a minor, if any, role for the enrichment of fluid-mobile elements in the mantle wedge. We infer that most, if not all, of the H2O produced by dehydration reactions between 600 and 900 °C is preserved in eclogite due to the pressure-enhanced capability of garnet and omphacite to incorporate structural water. Incorporation of H2O, produced during the final dehydration stage (c. 800 ± 50 °C, 25–30 kbar), in nominally anhydrous minerals may explain why partial melting obviously did not occur in eclogite.
CRIS-Team Scopus Importer:2021-02-05
Keywords: Eclogite; Element mobility; Erzgebirge; Geochemistry; Mantle wedge; Meta-basalt

Non-invasive determination of critical dissolved oxygen thresholds for stress physiology in fish using triple-oxygen stable isotopes and aquatic respirometry - Wassenaar, Leonard I.; Crespel, Amélie; Barth, Johannes; Koeck, Barbara; Závorka, Libor (Isotopes in Environmental and Health Studies, 2024)
Understanding the critical thresholds of dissolved oxygen (O2) that trigger adaptive physiological responses in aquatic organisms is long hampered by a lack of robust, non-lethal or non-invasive methodologies. The isotope fractionation of triple O2 isotopes (18O/17O/16O) during respiration is linked to the amount of oxygen utilised, offering a potential avenue for new insights. Our experimental research involved measuring the oxygen isotope fractionation of dissolved O2 in closed-system aquatic respirometry experiments with wild sticklebacks (Gasterosteus aculeatus). These fish were either naturally adapted or experimentally acclimated to hypoxic and normoxic conditions. The aim was to observe their oxygen usage and isotope fractionation in response to increasingly severe hypoxia. Initial observations revealed a progressive 18O enrichment from the preferential uptake of 16O to a dissolved oxygen threshold of 3–5 mg O2 L–1, followed by an apparent reversal in oxygen isotope fractionation, which is mixing of 16O and 17O with the remaining O2 pool across all populations and indicative of a systematic change in oxygen metabolism among the fish. Unexpectedly, sticklebacks adapted to hypoxia but acclimated to normoxia exhibited stronger oxygen isotope fractionation compared to those adapted to normoxia and acclimated to hypoxia, contradicting the hypothesis that hypoxia adaptation would lead to reduced isotope discrimination due to more efficient oxygen uptake. These preliminary experimental results highlight the novel potential of using dissolved O2 isotopes as a non-invasive, non-lethal method to quantitatively assess metabolic thresholds in aquatic organisms. This approach could significantly improve our understanding of the critical oxygen responses and adaptation mechanisms in fish and other aquatic organisms across different oxygen environments, marking a significant step forward in aquatic ecological and physiological research.
CRIS-Team Scopus Importer:2024-07-19
Keywords: acidosis; adaptation; aquatic animals; hypoxia; physiological stress; plasticity; Respiration; triple-oxygen isotopes

Norithamnium madoniensis Senowbari-Daryan, Keupp, Abate & Vartis-Matarangas, 2002 in the Anisian reef boulders from Karaburun Peninsula, Turkey - Senowbari-Daryan, Baba; Link, Michael (Journal of alpine geology, 2007)
From the Anisian reef boulders embedded within the Gerence Formation in Karaburun Peninsula, Turkey the species Norithamnium madoniensis (Corallinales, Rhodophyta) is described. The genus was known until now from the Norian-Rhaetian reef limestones of Sicily, Greece, and Austria. The Anisian of Karaburun is the fourth locality and probably the oldest occurrence.
UnivIS-Import:2015-04-14:Pub.2007.nat.dgeo.IGM.LP.norith
Keywords: Algae; Corallinales; Rhodophyta; Norithamnium; Anisian; Karaburun; Turkey

Normal giants? Temporal and latitudinal shifts of Palaeozoic marine invertebrate gigantism and global change - Klug, Christian; de Baets, Kenneth; Kröger, Björn; Bell, Mark Alan; Korn, Dieter; Payne, Jonathan Louis; de Baets, Kenneth (Lethaia, 2015)
During and after the Cambrian explosion, very large marine invertebrate species have evolved in several groups. Gigantism in Carboniferous land invertebrates has been explained by a peak in atmospheric oxygen concentrations, but Palaeozoic marine invertebrate gigantism has not been studied empirically and explained comprehensively. By quantifying the spatiotemporal distribution of the largest representatives of some of the major marine invertebrate clades (orthoconic cephalopods, ammonoids, trilobites, marine eurypterids), we assessed possible links between environmental parameters (atmospheric or oceanic oxygen concentrations, ocean water temperature or sea level) and maximum body size, but we could not find a straightforward relationship between both. Nevertheless, marine invertebrate gigantism within these groups was temporally concentrated within intervals of high taxonomic diversity (Ordovician, Devonian) and spatially correlated with latitudes of high occurrence frequency. Regardless of whether temporal and spatial variation in sampled diversity and occurrence frequency reflect true biological patterns or sampling controls, we find no evidence that the occurrences of giants in these groups were controlled by optimal conditions other than those that controlled the group as a whole; if these conditions shift latitudinally, occurrences of giants will shift as well. It is tempting to attribute these shifts to contemporary changes in temperature, oxygen concentrations in the atmosphere and the oceans as well as global palaeogeography over time, but further collection-based studies are necessary on finer stratigraphic and phylogenetic resolution to corroborate such hypotheses and rule out sampling or collection biases.
Keywords: Arthropoda; Cephalopoda; macroecology; mass extinctions; palaeodiversity; palaeogeography; Palaeozoic

North Atlantic intermediate water variability over the past 20,000 years - Yasuhara, Moriaki; deMenocal, Peter B.; Dwyer, Gary S.; Cronin, Thomas M.; Okahashi, Hisayo; Huang, Huai-Hsuan (Geology, 2019)
North Atlantic intermediate-water temperature variations based on ostracod Mg/Ca ratios from Ocean Drilling Program (ODP) Hole 1055B document a series of multi-centennial-scale abrupt warming events throughout the last deglaciation and Holocene (up to 3 °C). These events are coherent with abrupt climate reversals including Heinrich event 1, the Younger Dryas-Intra-Allerød cold period, and Holocene North Atlantic Deep Water (NADW) reduction periods. Deglacial-Holocene warm events were likely related to reduction in the strength of the upper NADW (Labrador Sea Water). We also found a long-term cooling trend in the ODP 1055 Mg/Ca record indicating continuous Labrador Sea Water strengthening throughout the Holocene. Our results help to better understand deglacial-Holocene upper NADW dynamics that remain poorly understood but can be important for regional and global climates.
CRIS-Team Scopus Importer:2019-07-09

Northeastern Atlantic cold-water coral reefs and climate - Frank, Norbert; Freiwald, André; López Correa, Matthias; Wienberg, Claudia; Eisele, Markus; Hebbeln, Dierk; van Rooij, David; Henriet, Jean-Pierre; Colin, Christophe; van Weering, Tjeerd; de Haas, Henk; Buhl-Mortensen, Pål; et al. (Geology, 2011)
U-series age patterns obtained on reef framework-forming cold-water corals collected over a nearly 6000-km-long continental margin sector, extending from off Mauritania (17°N; northwest Africa) to the southwestern Barents Sea (70°N; northeastern Europe), reveal strong climate infl uences on the geographical distribution and sustained development of these ecosystems. Over the past three glacial-interglacial cycles, framework-forming cold-water corals (Lophelia pertusa and Madrepora oculata) seem to have predominantly populated reefs, canyons, and patches in the temperate East Atlantic and the Mediterranean Sea. Above 50°N corals colonize reefs in the northern East Atlantic primarily during warm climate periods with the biogeographic limit advancing from 50°N to 70°N. We propose that north-south oscillations of the biogeographic limit of reef developments are paced by ice ages and may occur synchronously with north-south displacement of cold nutrient-rich intermediate waters and surface productivity related to changes of the polar front. © 2011 Geological Society of America.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LP.northe

Not all biodiversity rich spots are climate refugia - Kocsis, Ádám; Zhao, Qianshuo; Costello, Mark J.; Kiessling, Wolfgang (Biogeosciences, 2021)
Anthropogenic climate change is increasingly threatening biodiversity on a global scale. Rich spots of biodiversity, regions with exceptionally high endemism and/or number of species, are a top priority for nature conservation. Terrestrial studies have hypothesized that rich spots occur in places where long-term climate change was dampened relative to other regions. Here we tested whether biodiversity rich spots are likely to provide refugia for organisms during anthropogenic climate change. We assessed the spatial distribution of both historic (absolute temperature change and climate change velocities) and projected climate change in terrestrial, freshwater, and marine rich spots. Our analyses confirm the general consensus that global warming will impact almost all rich spots of all three realms and suggest that their characteristic biota is expected to witness similar forcing to other areas, including range shifts and elevated risk of extinction. Marine rich spots seem to be particularly sensitive to global warming: they have warmed more, have higher climate velocities, and are projected to experience higher future warming than non-rich-spot areas. However, our results also suggest that terrestrial and freshwater rich spots will be somewhat less affected than other areas. These findings emphasize the urgency of protecting a comprehensive and representative network of biodiversity-rich areas that accommodate species range shifts under climate change.
CRIS-Team Scopus Importer:2024-12-16

Notes on Palaeontological Societies - Reich, Mike; Gehler, Alexander; Roden, Vanessa (Jahrestagung der Paläontologischen Gesellschaft. 8.-10. September 2008, Erlangen, 2008)

Novel evaluations of sources and sinks of dissolved oxygen via stable isotopes in lentic water bodies - Dordoni, Marlene; Seewald, Michael; Rinke, Karsten; Schmidmeier, Jakob; Barth, Johannes (Science of the Total Environment, 2022)
Dissolved oxygen (DO) dynamics of a temperate drinking water reservoir in the Harz Mountains (Germany) were investigated over a time period of 18 months. Via depth profiles in a fortnightly sampling resolution we were able to trace DO and temperature dynamics including the formation and breakdown of a Metalimnetic Oxygen Minimum (MOM) by means of DO concentration, saturation patterns and stable isotope ratios of dissolved oxygen (expressed as δ18ODO). Over the evaluation period, 19.4 % of the samples collected had δ18ODO values compatible with atmospheric equilibration (+24.6 ‰ ± 0.4 ‰). With values smaller and larger than this threshold, the remaining δ18ODO values showed that 40.8 % of our samples were dominated by photosynthesis and 39.8 % by respiration. From December to April the reservoir was mixed and DO consumption by respiration exceeded production via photosynthesis. During stratification period, quantification of respiration/photosynthesis rates (R/P) confirmed the epilimnion as a photosynthetic (i.e. net-autotrophic) environment while the hypolimnion was heterotrophic and dominated by respiration at various degrees. Samples of the MOM zone showed the highest R/P ratios and had among the most positive δ18ODO signals caused by respiration. This study showed that combinations of DO concentrations and their isotope ratios are promising to quantify critical zones of respiration and photosynthesis in aquatic environments.
CRIS-Team Scopus Importer:2022-07-01
Keywords: Atmospheric influence; Lentic water bodies; Metalimnetic Oxygen Minimum (MOM); Photosynthesis; R/P ratios; Respiration

Numerical modeling and inverse parameter estimation of the large-scale mass movement Gradenbach in Carinthia (Austria) - Meier, Joerg; Moser, Michael; Datcheva, Maria; Schanz, Tom (Acta Geotechnica, 2013)
Keywords: Parameter identification; Mathematical optimization; Statistic parameter analysis

Numerical Modelling of Seismic Site Effects Incorporating Non-linearity and Groundwater Level Changes - Ehret, Dominik; Rohn, Joachim; Hannich, Dieter; Grandas, Carlos; Huber, Gerhard (Journal of Earth Science, 2010)
In the past decades, the necessity for detailed earthquake microzonation studies was recognized worldwide. Therefore, different approaches were established and applied. Unfortunately, the majority of these approaches are not based on pre-existing field data but require extensive seismic measurements and investigations. Furthermore, these approaches incorporate non-linearity inadequately and cannot take groundwater level changes into account. For this purpose, notably numerical models are most suitable. These models require a good knowledge of the local geological conditions (especially of the uppermost unconsolidated units), information about the geotechnical parameters of these units, and a hydrogeological model of the investigated area. Most of this information can be obtained from geotechnical investigations and surveys that have already been carried out in most densely populated areas. In a case study for Bucharest City, non-linear analyses were performed using software that is based on the visco-hypoplastic constitutive law. The results indicate that groundwater level changes have an important influence on duration and amplitude of ground response and thus should be considered for seismic microzonation studies. This approach can be used to display site effects and to identify different microzones taking different earthquake magnitudes and groundwater levels into account. © 2010 China University of Geosciences and Springer-Verlag Berlin Heidelberg.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.profes_3.numeri
Keywords: Bucharest; microzonation; non-linearity; Romania; site effect; visco-hypoplasticity

Numerical Simulation of Qiaotou Landslide Deformation Caused by Drawdown of the Three Gorges Reservoir, China - Jiang, Jiwei; Ehret, Dominik; Xiang, Wei; Rohn, Joachim; Huang, Ling; Yan, Shaojun; Bi, Renneng (Environmental Earth Sciences, 2011)
Landslides located beside reservoirs tend to be unstable or are characterized by large deformation during the drawdown process. This has been accepted by many experts. In this paper, we use Qiaotou Landslide, which is located beside the Three Gorges Reservoir (TGR), as a typical case study to investigate and predict the deformation mechanism during the drawdown process of TGR in detail. According to field investigation, the landslide mass is mainly composed of thick, loose silt and clay mixed with fragments of rock. Bedrock is mainly composed of silty sandstone. Field and laboratory tests indicate that the landslide mass has a high permeability coefficient. If the water level declines fast, intense seepage force may result. Based on these data, we establish a three-dimensional geological model of Qiaotou Landslide by FLAC3D and perform a numerical simulation using the saturated-unsaturated fluid-solid coupling theory. For the simulation, we assume that the drawdown from 175 to 145 m takes place with a speed of 25 cm/day, which is based on the extreme water level regulation program of TGR. The simulation shows that this causes a significant deformation in the landslide mass and that the maximum displacement within the landslide is 24.2 cm. During the drawdown process, the maximum displacement zone is shifting from the upper part of the landslide where bedrock surface is steeper and thickness of loose deposits is less to the middle part of the landslide where bedrock surface is less steep and thickness of loose deposits is higher. The deformation mechanism indicates that in the early stage of the drawdown the deformation of the landslide mass is mainly caused by seepage and in the later stage mainly by consolidation. © 2010 Springer-Verlag.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.profes_3.numeri
Keywords: Deformation prediction of landslide; Numerical simulation; Reservoir drawdown; Saturated-unsaturated seepage; Three Gorges Reservoir

Nuptial feeding is reflected in tissue nitrogen isotope ratio in female katydids - Joachimski, Michael; et al. (Functional Ecology, 2006)
1. During copulation male katydids transfer a protein-rich nuptial gift to females, which is ingested by the female. We hypothesized that female katydids are built at least partly from proteins assimilated from nuptial gifts. 2. We measured the ratio of nitrogen isotopes (δ15N) in the diet and tissue of sexually reproducing Isophya kraussii and obligate parthenogenetically reproducing Poecilimon intermedius. We used the δ15N of muscles as an indicator of the most recent diet and the δ15N of the cuticula as an indicator of the larval diet. 3. In free-ranging I. kraussi, muscular and cuticular δ15N of adult males was low, suggesting a plant diet. Cuticular δ15N did not differ between sexes, indicating that immatures of both sexes fed on similar diets. Female muscles were significantly more enriched in nitrogen-15 than female cuticula and also than male muscles, suggesting that adult females incorporated animal proteins and immature females plant material. 4. Female I. kraussii that were kept with males in captivity had higher δ15N in muscular tissue than in cuticula. Muscular δ15N of these females was also higher than that of muscle and cuticula of females held isolated from males, suggesting that incorporated nitrogen originated from nuptial gifts. 5. In parthenogenetically reproducing P. intermedius muscular and cuticular δ15N was almost identical, suggesting no additional uptake of insect proteins in the absence of nuptial gifts. 6. We therefore conclude that female I. kraussii substantially assimilate spermatophylax compounds for both egg production and body homeostasis. © 2006 The Authors.
UnivIS-Import:2015-03-09:Pub.2006.nat.dgeo.IGM.LG.nuptia
Keywords: Homeostasis; Isophya; Nitrogen source; Spermatophore; Stable isotopes

Oases of biodiversity: Early Devonian palaeoecology of Hamar Laghdad, Morocco - Klug, Christian; Samankassou, Elias; Pohle, Alexander; de Baets, Kenneth; Franchi, Fulvio; Korn, Dieter (Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, 2018)
The mudmound locality of Hamar Laghdad (Tafilalt Platform) contains possibly the greatest palaeobiodiversity, both horizontally in the surrounding sediments and stratigraphically through the Devonian sedimentary succession of the Moroccan eastern Anti-Atlas. From the Ordovician to the Devonian, sediments of the Hamar Laghdad region and their fossil contents tend to differ slightly from those in time-equivalent strata of other parts of the Tafilalt Platform. Our research provides a description of the sedimentological and palaeontological record of Hamar Laghdad covering the Lochkovian to Givetian interval. We use alpha-diversity data based on macrofossils from selected fossiliferous strata and compare the results with the relative abundance of bioclasts in polished sections. We show that the palaeobiodiversity of Hamar Laghdad was similar to that of the southern Tafilalt with a normal diversity during the Pragian, i.e. prior to mudmound initiation and growth. By contrast, the layers covering the massive mudmound carbonates (e.g., when their activity had ceased) show a high diversity during the latest Emsian with a trophic nucleus comprising 36 species. This fauna, here exemplified by the ‘Red Fauna’ (from the Red Cliff), is dominated by benthic suspension feeders (corals, brachiopods and crinoids) and cephalopods. The shift in biodiversity is most likely related to the local occurrence of a favourable environmental setting, characterized by a temporally and spatially varying topography. It is assumed that this setting was influenced by sea-level fluctuations, currents and nutrient availabilit

Oberflächennah bis kilometertief – Lehre und Forschung zur Geothermie an der FAU Erlangen - Stollhofen, Harald; Bauer, Wolfgang; Bertermann, David; Drews, Michael; Fazlikhani, Hamed (Geothermische Energie, 2018)
Geothermie-Forschung am GeoZentrum Nordbayern (GZN) der Friedrich-Alexander-Universität (FAU) ist auf die integrierte fazielle, petrographische, petrophysikalische und geomechanische Charakterisierung von Reservoirgesteinen und deren Exploration ausgerichtet. Zudem werden pedologische bzw. geophysikalische Systemzusammenhänge im Bereich der oberflächennahen Geothermie analysiert. Ein neuer Masterstudiengang "GeoThermie/GeoEnergie" zielt auf die Vermittlung eines ganzheitlichen Systemverständnisses.

Oberflächennahste Geothermiesysteme als Quelle für kalte Nahwärmenetze - Bertermann, David; Wienke, Jeannette; Müller, Johannes; Böck, Sebastian; Lach, Gerald; Steinhäuser, Harry (bbr - Leitungsbau, Brunnenbau, Geothermie, 2019)

Oblique magnetic fabric in siderite-bearing pelitic rocks of the Upper Carboniferous Culm Basin, SW England: An indicator for palaeo-fluid migration? - de Wall, Helga; Warr, Laurence N. (2004)

Obsidian clasts as sintered remnants of agglutination processes in volcanic conduits, evidence from the Pepom tephras (Sete Cidades), São Miguel, Azores - Ellis, B. S.; Pimentel, A.; Cortes-Calderon, E. A.; Moser, Z.; Baumann, Nils; Bachmann, O.; Wadsworth, F. B. (Chemical Geology, 2023)
The youngest explosive eruptions of the Sete Cidades volcano, São Miguel, Azores, are recorded by a series of relatively small-volume (<0.03 to 0.13 km3 DRE) trachytic pyroclastic deposits termed the Pepom tephra deposits. While dominated by crystal-poor to crystal-moderate (<10%) pumice clasts, these deposits also contain a suite of dense glassy clasts of broadly similar crystallinity. The obsidian clasts from a single deposit vary in texture from entirely dense to those that are moderately vesicular and typically single clasts will contain multiple textural domains. The majority (∼71%) of these dense clasts have compositions both from bulk rock and in-situ glass measurements that are identical to those of the pumice clasts within the same deposit. We interpret these dense clasts to reflect sintering of previously fragmented magma at shallow levels in the conduit prior to being re-entrained and erupted with the vesicular magma, in agreement with recent studies focussing on textural observations. Notably, across the exposed volcanic stratigraphy of São Miguel obsidian domes, flows/coulees are not preserved, arguing against the idea that the dense glass clasts within the Pepom tephras are sourced from existing surficial rocks. In contrast, the neighbouring island of Terceira exhibits domes and coulees with large obsidian bands that cut through the crystalline groundmass. Most silicic rocks of Santa Bárbara and Pico Alto volcanoes on Terceira are peralkaline, comenditic to pantelleritic in composition, and at similar conditions (e.g., temperature and water content) have lower viscosities than the trachytic Pepom obsidian clasts. However, the Santa Bárbara silicic lavas on Terceira (the less peralkaline suite) have more obsidian than the more peralkaline Pico Alto domes and coulees indicating that while peralkalinity, developed during magmatic evolution in the crust, may play a role, sintering occurring at shallow levels within the conduit likely is more important in producing obsidian.
CRIS-Team Scopus Importer:2023-09-29
Keywords: Azores; Geochemistry; Obsidian; Sintering; Trachyte

Occurrence and fate of perfluorinated compounds in sewage sludge from Spain and Germany - Gomez-Canela, Cristian; Barth, Johannes; Lacorte, Silvia (Environmental Science and Pollution Research, 2012)

Ocean and Coastal Ecosystems and their Services, in: Climate Change 2022: Impacts, Adaptation and Vulnerability. Working Group II Contribution to the IPCC Sixth Assessment Report - Cooley, Sarah; Schoeman, David; Bopp, Laurent; Boyd, Philip; Donner, Simon; Ghebrehiwet, Dawit Yemane; Ito, Shin-Ichi; Kießling, Wolfgang; Martinetto, Paulina; Ojea, Elena; Racault, Marie-Fanny; Rost, Björn; et al. (Climate Change 2022: Impacts, Adaptation and Vulnerability. Working Group II Contribution to the IPCC Sixth Assessment Report, 2022)
Anthropogenic climate change has exposed ocean and coastal ecosystems to conditions that are unprecedented over millennia (high confidence2), and this has greatly impacted life in the ocean and along its coasts (very high confidence). Fundamental changes in the physical and chemical characteristics of the ocean acting individually and together are changing the timing of seasonal activities (very high confidence), distribution (very high confidence), and abundance (very high confidence) of oceanic and coastal organisms, from microbes to mammals and from individuals to ecosystems, in every region. Evidence of these changes is apparent from multi-decadal observations, laboratory studies and mesocosms, as well as meta-analyses of published data. Geographic range shifts of marine species generally follow the pace and direction of climate warming (high confidence): surface warming since the 1950s has shifted marine taxa and communities poleward at an average (mean ± very likely range) of 59.2 ± 15.5 km per decade (high confidence), with substantial variation in responses among taxa and regions. Seasonal events occur 4.3 ± 1.8 to 7.5 ± 1.5 days earlier per decade among planktonic organisms (very high confidence) and on average 3 ± 2.1 days earlier per decade for fish (very high confidence). Warming, acidification and deoxygenation are altering ecological communities by increasing the spread of physiologically sub-optimal conditions for many marine fish and invertebrates (medium confidence). These and other responses have subsequently driven habitat loss (very high confidence), population declines (high confidence), increased risks of species extirpations and extinctions (medium confidence) and rearrangement of marine food web
Keywords: anthropogenic; climate; change; geographic range shifts; range; shifts; marine; species; warming; acidification; deoxygenation; invertebrates; fish; extinctions; rearrangement

Oceanic island biogeography through the lens of the general dynamic model: Assessment and prospect - Borregaard, Michael K.; Amorim, Isabel R.; Borges, Paulo A. V.; Cabral, Juliano S.; Fernandez-Palacios, Jose M.; Field, Richard; Heaney, Lawrence R.; Kreft, Holger; Matthews, Thomas J.; Olesen, Jens M.; Price, Jonathan; Rigal, Francois; et al. (Biological Reviews, 2017)
The general dynamic model of oceanic island biogeography (GDM) has added a new dimension to theoretical island biogeography in recognizing that geological processes are key drivers of the evolutionary processes of diversification and extinction within remote islands. It provides a dynamic and essentially non-equilibrium framework generating novel predictions for emergent diversity properties of oceanic islands and archipelagos. Its publication in 2008 coincided with, and spurred on, renewed attention to the dynamics of remote islands. We review progress, both in testing the GDM's predictions and in developing and enhancing ecological–evolutionary understanding of oceanic island systems through the lens of the GDM. In particular, we focus on four main themes: (i) macroecological tests using a space-for-time rationale; (ii) extensions of theory to islands following different patterns of ontogeny; (iii) the implications of GDM dynamics for lineage diversification and trait evolution; and (iv) the potential for downscaling GDM dynamics to local-scale ecological patterns and processes within islands. We also consider the implications of the GDM for understanding patterns of non-native species diversity. We demonstrate the vitality of the field of island biogeography by identifying a range of potentially productive lines for future research.
Keywords: Archipelago; Diversity theory; General dynamic model; Island biogeography; Island evolution; Trait evolution; Volcanic islands

Ocean temperatures through the Phanerozoic reassessed - Grossman, Ethan; Joachimski, Michael (Scientific Reports, 2022)
The oxygen isotope compositions of carbonate and phosphatic fossils hold the key to understanding Earth-system evolution during the last 500 million years. Unfortunately, the validity and interpretation of this record remain unsettled. Our comprehensive compilation of Phanerozoic δ18O data for carbonate and phosphate fossils and microfossils (totaling 22,332 and 4615 analyses, respectively) shows rapid shifts best explained by temperature change. In calculating paleotemperatures, we apply a constant hydrosphere δ18O, correct seawater δ18O for ice volume and paleolatitude, and correct belemnite δ18O values for 18O enrichment. Similar paleotemperature trends for carbonates and phosphates confirm retention of original isotopic signatures. Average low-latitude (30° S–30° N) paleotemperatures for shallow environments decline from 42.0 ± 3.1 °C in the Early-to-Middle Ordovician to 35.6 ± 2.4 °C for the Late Ordovician through the Devonian, then fluctuate around 25.1 ± 3.5 °C from the Mississippian to today. The Early Triassic and Middle Cretaceous stand out as hothouse intervals. Correlations between atmospheric CO2 forcing and paleotemperature support CO2’s role as a climate driver in the Paleozoic.<br

OH 83: A new early modern human fossil cranium from the Ndutu beds of Olduvai Gorge, Tanzania - Reiner, Whitney B.; Masao, Fidelis; Sholts, Sabrina B.; Songita, Agustino Venance; Stanistreet, Ian; Stollhofen, Harald; Taylor, R. E.; Hlusko, Leslea J. (American Journal of Physical Anthropology, 2017)
Objective: Herein we introduce a newly recovered partial calvaria, OH 83, from the upper Ndutu Beds of Olduvai Gorge, Tanzania. We present the geological context of its discovery and a comparative analysis of its morphology, placing OH 83 within the context of our current understanding of the origins and evolution of Homo sapiens. Materials and methods: We comparatively assessed the morphology of OH 83 using quantitative and qualitative data from penecontemporaneous fossils and the W.W. Howells modern human craniometric dataset. Results: OH 83 is geologically dated to ca. 60–32 ka. Its morphology is indicative of an early modern human, falling at the low end of the range of variation for post-orbital cranial breadth, the high end of the range for bifrontal breadth, and near average in frontal length. Discussion: There have been numerous attempts to use cranial anatomy to define the species Homo sapiens and identify it in the fossil record. These efforts have not met wide agreement by the scientific community due, in part, to the mosaic patterns of cranial variation represented by the fossils. The variable, mosaic pattern of trait expression in the crania of Middle and Late Pleistocene fossils implies that morphological modernity did not occur at once. However, OH 83 demonstrates that by ca. 60–32 ka modern humans in Africa included individuals that are at the fairly small and gracile range of modern human cranial variation.
Keywords: evolution; paleoanthropology; paleontology; pleistocene; variation

OH point defects in olivine from Pakistan - Schmädicke, Esther; et al. (Mineralogy and Petrology, 2010)

Okorusu tailings – Part II: REE mineralisation, and oxygen and carbon isotope variations - Lohmeier, S.; Machleidt, Jakob; Klemd, Reiner; Ellmies, R. (South African Journal of Geology, 2023)
The Okorusu carbonatite complex and the mine’s tailings dump constitute a potential resource of rare earth elements meaning lanthanides and yttrium (REY). Small (≤100 μm), hydrothermal REE fluorcarbonates (bastnäsite, parisite, röntgenite and synchysite) are the principal light REE carriers while the heavy REE and Y are primarily hosted in magmatic apatite, magmatic-hydrothermal carbonates (calcite, dolomite, ankerite) and hydrothermal fluorite. Bastnäsite and röntgenite occur as individual, liberated crystals in the tailings albeit syntaxial intergrowths of acicular parisite-synchysite-röntgenite are more common. There is a clear trend of decreasing REY contents in the magmatic carbonates over the early hydrothermal carbonates to the late hydrothermal carbonates. The lower total REY abundance in the hydrothermal carbonates is interpreted to be mainly a consequence of their limited redistribution during hydrothermal activity following the breakdown of the primary magmatic minerals and precipitation of REE fluorcarbonates. During this process hydrothermal fluids changed the isotopic composition of the Okorusu carbonatites by shifting δ13C-δ18O pairs of magmatic carbonatite (δ13C:-6.5‰ to-5.4‰; δ18O: +6.4‰ to +11.2‰) to higher values of hydrothermally modified carbonatite (δ13C:-4.2 to-2.2; δ18O: +12.0‰ to +17.5‰). The preferential presence of REY in the magmatic carbonates and to a minor degree in the hydrothermal carbonates in the Okorusu carbonatite and tailings is an important exploration tool for primary magmatic REY mineralisations. The recovery of REE fluorcarbonates can be considered in the development of the flowsheet for the planned recycling of the tailings material as a potential REY by-product.
CRIS-Team Scopus Importer:2023-11-03

Oldest known Stereospondylous amphibian from the Early Permian of Namibia. - Stollhofen, Harald; et al. (PalArch's Journal of Vertebrate Palaeontology, 2001)
UnivIS-Import:2015-03-09:Pub.2001.nat.dgeo.IGM.LG.oldest

Olduvai's oldest Oldowan - Stollhofen, Harald; Stanistreet, Ian G.; Toth, Nicholas; Schick, Kathy D.; Rodriguez-Cintas, Agata; Albert, Rosa M.; Farrugia, Paul; Njau, Jackson K.; Pante, Michael C.; Herrmann, Edward W.; Ruck, Lana; Bamford, Marion K.; et al. (Journal of Human Evolution, 2021)
Previously, Olduvai Bed I excavations revealed Oldowan assemblages <1.85 Ma, mainly in the eastern gorge. New western gorge excavations locate a much older similar to 2.0 Ma assemblage between the Coarse Feldspar Crystal Tuff (similar to 2.015 Ma) and Tuff IA (similar to 1.98 Ma) of Lower Bed I, predating the oldest eastern gorge DK assemblage below Tuff IB by similar to 150 kyr. We characterize this newly discovered fossil and artifact assemblage, adding information on landscape and hominin resource use during the similar to 2.3-2.0 Ma period, scarce in Oldowan sites. Assemblage lithics and bones, lithofacies boundaries, and phytolith samples were surveyed and mapped. Sedimentological facies analysis, tephrostratigraphic and sequence stratigraphic principles were applied to reconstruct paleoenvironments and sedimentary processes of sandy claystone (lake), sandstone (fluvial), and sandy diamictite (debris flow) as principal lithofacies. Artifacts, sized, weighed, categorized, were examined for petrography, retouch, and flake scar size. Taxonomic classifications and taphonomic descriptions of faunal remains were made, and phytoliths were categorized based on reference collections. Lithics are dominantly quartzite, mainly debitage and less frequently simple cores, retouched pieces, and percussors. Well-rounded spheroids and retouched flakes are rare. Identifiable taxa, Ceratotherium cf. simum (white rhinoceros) and Equus cf. oldowayensis (extinct zebra), accord with nearby open savanna grasslands, inferred from C-3 grass, mixed and/or alternating with C-4 grass-dominated phytolith assemblages. Palms, sedges, and dicots were also identified from phytoliths. Diatoms and sponge spicules imply nearby freshwater. The assemblage accumulated at the toe of a Ngorongoro Volcano-sourced fan-delta apron of stacked debris flows, fluvials, and tuffs, preserving fossil tree stumps and wooded grassland phytoliths farther upfan. It formed after the climax of Ngorongoro volcanic activity during a Paleolake Olduvai lowstand and was then buried and preserved by lacustrine clays, marking the first of two lake transgressions, signifying wetter climates. Orbital precessional lake cycles were superposed upon multimillennial (similar to 4.9 kyr) lake fluctuations. (C) 2020 Elsevier Ltd. All rights reserved.
CRIS-Team WoS Importer:2021-01-15

Olivine from spinel peridotite xenoliths: Hydroxyl incorporation and mineral composition - Schmädicke, Esther; et al. (American Mineralogist, 2012)
Keywords: Olivine; Nominally anhydrous minerals; Trace elements; Spinel peridotite; Water content

On- and off-axis chemical heterogeneities along the South Atlantic Mid-Ocean-Ridge (5-11°S): Shallow or deep recycling of ocean crust and/or intraplate volcanism? - Hoernle, Kaj; Hauff, Folkmar; Kokfelt, Thomas; Haase, Karsten; Garbe-Schönberg, Dieter; Werner, Reinhard (Earth and Planetary Science Letters, 2011)
The Mid-Atlantic Ridge between the Ascension and Bode Verde Fracture Zones exhibits anomalous crustal thickness and geochemical compositions, which could reflect the presence of either small, enriched heterogeneities in the upper mantle or a weak, diffuse mantle plume. We report new trace element (106 samples) and Sr, Nd and Pb (double spike) isotope data from 72 ridge axis samples and 9 off-axis seamount samples between 5 and 11°S, as well as U-Th-Ra disequilibria data for the seamounts. The U-series data constrain the age of one sample from Seamount D, furthest (120km) east of the shallowest part of the ridge, to be <10,000yrs old and the samples from the other three seamounts closer to the ridge to be younger than 240,000yrs. As can be most clearly discerned on a diagram of Pb/Pb vs. Nd/Nd, at least four distinct components are required to explain the geochemical variations along the ridge: 1) a common depleted (D-MORB-like) component in samples near and north of the Ascension Fracture Zone (4.8-7.6°S), representing the most depleted compositions sampled thus far along the mid-Atlantic ridge, 2) an enriched component upwelling beneath Ascension Island and the northern A1 ridge segment (segment numbers increase from A1 to A4 going south from the Ascension Fracture Zone), 3) an enriched component upwelling beneath the A2 ridge segment, and 4) an enriched component upwelling beneath the line of seamounts east of the A3 segment and the A3 and A4 segments. The A1 and the A3+A4 segment lavas form well-defined mixing arrays, which extend from Ascension Island and the A3 seamounts respectively to the depleted D-MORB component, interpreted to reflect local ambient mantle. We propose that the enriched components represent different packages of subducted ocean crust and/or ocean island basalt (OIB) type volcanic islands and seamounts that have either been recycled through 1) the shallow mantle, upwelling passively beneath the ridge system or 2) the deep mantle via an actively upwelling heterogeneous mantle plume that interacts with the ridge system. © 2011 Elsevier B.V.
Keywords: Ascension hotspot; Mantle plume-ridge interaction; Southern Atlantic Mid-Ocean Ridge; Trace element and Sr-Nd-Pb isotope geochemistry; U-series age dating

One-Year Monitoring of a Ground Heat Exchanger Using the In Situ Thermal Response Test: An Experimental Approach on Climatic Effects - Suft, Oliver; Bertermann, David (Energies, 2022)
The use of renewable energies, and of geothermal energy in particular, is increasingly being applied in Germany and Europe for the development of new residential districts. The use of geothermal borehole heat exchangers (BHE), in combination with ground-source heat pumps (GSHP), represents an important part of shallow geothermal systems, which are used, among other systems, in urban areas due to their small space requirements. Over the course of planning BHE systems, performance must be determined via the parameters of thermal conductivity, thermal capacity, undisturbed ground temperature, and borehole thermal resistance. These can be identified by the experimental approach known as thermal response testing (TRT). The thermal parameters change due to the influences of the seasonal temperature fluctuations that take place in the ground. In this paper, a pilot double-U BHE heat exchanger field with a depth of 120 m was investigated from this perspective. TRT was carried out using monthly measurements taken over the period of one year using an electrically powered mobile TRT device. The evaluation of the individual tests was carried out using the line-source, moving-line-source, and cylinder-source theories. Our results show that the season in which TRT was implemented had an influence on the determined thermal parameters, with better thermal conditions being obtained in winter months. This is especially visible for thermal conductivity, with monthly deviations of 0.1 W/(m∙K), independent of the evaluation approaches used.<br

On Paleozoic platycerate gastropods - Nützel, Alexander; Ebbestad, Jan Ove; Seuß, Barbara; Munnecke, Axel; Mapes, Royal H.; Cook, Alex G. (Zitteliana, 2023)

Onshore equivalents of the main Kudu gas reservoir in Namibia. - Stanistreet, Ian G.; Stollhofen, Harald (The oil and gas habitats of the South Atlantic, 1999)
Radiometric dates of Jurassic and Cretaceous flood basalts of the southern South Atlantic maritimes have thrown the stratigraphic contexts of Karoo and post-Karoo sequences into considerable question. Central to the problem is the status of volcano-sedimentary units, characterized by aeolian-related sedimentary interlayers, containing evaporites and other lacustrine elements. The main Kudu gas reservoir ('Lower Gas Sand') offshore Namibia, interleaved with undated flood basalts, is a prime example. A previously proposed onshore correlate is the fluvio-aeolian Etjo Sandstone, with a central Namibian type area, and comparisons have been made, particularly with units traditionally classified as Etjo Sandstone, near the Etendeka Plateau base in northwest Namibia, now recognized to be of younger age. We time-correlate the main Kudu Sandstone reservoir, however, with evaporitic fluvio-lacustrine and aeolian interlayers beneath and interleaved with Early Jurassic Kalkrand flood basalts of southern Namibia, situated onshore almost directly opposite the Kudu Field. The main Kudu Sandstone reservoir is transitional in palaeoenvironmental setting between Early Jurassic onshore analogues. Main Kudu reservoir geometries and associated lithologies can be better constrained with knowledge derived from Kalkrand sedimentary interlayers and their tectonic and volcanic controls. Kalkrand interlayer thicknesses are controlled primarily by down-to-the-east extensional fault system half-graben geometries, antithetic to an inferred down-to-the-west master detachment. Within resulting sub-basinal accommodation space, lava topography controlled thickness variation. When Kalkrand insights are taken into account with radiometric dating and biostratigraphy, a Namibian Mesozoic framework fixes Kudu reservoirs and analogues into a southern Gondwanan context. At least in its type area in central Namibia, the Etjo Formation is Early Jurassic, discounting a previously proposed widespread <100 Ma hiatus along a sub-Etjo disconformity. Instead, sequence boundary hiatuses of Permian-Triassic, Early Jurassic and Middle Jurassic-Early Cretaceous ages represent time-stratigraphic gaps, relating to major faulting episodes, recording extensional events associated with continental margin evolution. Understanding onshore analogues and refining the Namibian Mesozoic framework should help constrain seismic analysis of the Namibian margin and hydrocarbon reservoir geometries. Consequently, exploration focus should widen to include Karoo sequences beneath the basal Early Cretaceous transgression.
UnivIS-Import:2015-04-20:Pub.1999.nat.dgeo.IGM.LG.onshor

On the Age-Old Problem of Dating a Granite: Combined Zircon, Apatite, and Titanite Petrochronology in an I-Type Granite from Mt Stirling, Australia - Hoseong, L. I.M.; Nebel, Oliver; Jacobsen, Yona; Park, Jongkyu; Myeong, Bora; Raveggi, Massimo; Barrote, Vitor R.; Etschmann, Barbara; Nicholls, Ian A.; Cawood, Peter A. (Journal of Petrology, 2024)
To address the limitations of current dating methods, it is crucial to not only enhance existing techniques like U–Pb zircon dating but also explore alternative tools. This study focuses on three common mineral phases—zircon, apatite, and titanite—in an I-type granite. The goal is to assess their reliability as dating tools and propose improved methods for dating granitic rocks. In the case study of the Mt Stirling pluton within the Mt Buller igneous suite in Southeastern Australia, significant variability in laser ablation U–Pb zircon ages (around 100 million years) was observed. To improve the reliability of zircon age data and reduce non-magmatic-related variabilities, a data filtering protocol is applied. This protocol involves several steps such as trimming zircons with excessive K and Ca, excluding zircons with unusual core–rim age relationships, removing zircons with excessive non-formula elements (Al, Fe, and Mn), identifying hydrothermally altered zircons, and applying a 10% discordance threshold. The filtered Concordia Age (406 ± 1 Ma; mean square weighted deviation (MSWD) = 0.7, n = 80) of the host rock exhibits improved precision and reduced error compared to the unfiltered data (399 ± 2 Ma; MSWD = 9.3, n = 240). The filtered individual dates show less scatter and a mean that is different (i.e. outside statistical uncertainty), noting that their total still spans a considerable time range of ∼50 million years, exceeding the individual zircon analytical reproducibility of 2 standard errors (∼15 million years of 2 SE). Caution is advised when using the proposed error for the pooled analyses as a definitive precision. Similarly, trace element filtering approaches were applied to apatite and titanite samples from Mt Stirling, two phases that arguably cannot be inherited. For apatite, monitoring Ca and P as well as Zr/Y and Th/U ratios, along with identifying age groupings based on Sr concentrations, was effective in eliminating outliers and enhancing dating precision. In the case of titanite, monitoring Ca and Ti, Sr/Zr and Sr/Th ratios, and Sr/Ca and Zr/Ti ratios successfully enhanced dating precision. Notably, apatite and titanite grains were grouped in distinct Sr concentrations (high-, mid-, and low-Sr), with these groups corresponding to different date groups: high-Sr apatite and high- and low-Sr titanite returned c. 403 Ma, while low-Sr apatite and mid-Sr titanite returned c. 420 and 393 Ma, respectively. The spuriously younger or older dates may indicate an open system and inf luences from various common-Pb sources. The 403 Ma date coincides with the filtered zircon data, placing further confidence in the coupled approach, and is interpreted here as the igneous intrusion age. Notable is that this age is 25 Myr older than previously reported K–Ar age data, thus far considered to be the age of the intrusion. This study underscores the potential for erroneous zircon dates due to cryptic chemical inf luences. To enhance the reliability of age interpretation using laser ablation analyses, employing a petrochronological approach using split-stream combined age and trace element data is recommended in addition to the combination of multiple geochronometers. In the case of Mt Buller, it has proven crucial to carefully verify chemical closure of all applied geochronometers by monitoring concomitant trace element concentrations. Applied to other intrusions, petrochronology can play a critical role in obtaining reliable age information, even for igneous rocks that appear pristine. With this, we emphasise the importance of a careful approach towards individual age data interpretation, which can be produced fast and in abundance with modern analytical approaches.
CRIS-Team Scopus Importer:2024-08-09
Keywords: apatite; granite petrogenesis; petrochronology; titanite; zircon

On the assignment of quartz-like LiAlSi2O6 - SiO2 solid solutions in dental lithium silicate glass-ceramics: Virgilite, high quartz, low quartz or stuffed quartz derivatives? - Hurle, Katrin; Lubauer, Julia; Belli, Renan; Lohbauer, Ulrich (Dental Materials, 2022)
Objectives: Here we aim to provide a background on X-Ray Diffraction analysis of quartz-like crystal structures with varying amounts of Al3+ and Li+ substitution, existing confusions on their nomenclature and its implications for novel lithium silicate glass-ceramics. Methods: We reviewed the literature dealing with modifications of the quartz crystal structure and their stuffed LiAlSi2O6 derivates, LiAlSi2O6 – SiO2 solid solutions, the terminology of such phases and criteria used to define the structure known as virgilite. Based on this information, we attempted to allocate the quartz-like phases found in CEREC TesseraTM, InitialTM LiSi Block and Amber® Mill in the range of LiAlO2 - SiO2 solid solutions. For this purpose, their lattice parameters obtained from Rietveld refinement were compared with the lattice parameters of members of the corresponding solid solutions with defined SiO2 molar fraction found in the literature. Results: Based on the lattice parameters available for low quartz, high quartz and its stuffed derivatives, including LiAlSi2O6 and the mineral virgilite, a plot of the a- and c-parameters vs. the mol% SiO2 related to LiAlO2 was constructed with the literature data and the data found for the three dental lithium silicates. As per the definitions of virgilite as either LixAlxSi3-xO6, with 0.5 < x < 1 or especially as members of the LiAlSi2O6 – SiO2 solid-solution series with more than 50 mol% LiAlSi2O6, the crystal structures in CEREC TesseraTM, InitialTM LiSi Block and Amber® Mill failed to fall within the ranges of mol% SiO2 confined for virgilite. Significance: Based on available literature and definitions, the quartz-like phases found in the three dental lithium silicates should be addressed as stuffed (probably low) quartz solid solutions instead of “virgilite”. However determined by mineralogical practices, the term “virgilite” for parts of the LiAlSi2O6 – SiO2 solid solution is ambiguous and can be considered as arbitrary.
CRIS-Team Scopus Importer:2022-08-12
Keywords: Crystal; Glass-ceramics; Lithium silicate; Quartz; Virgilite; X-ray diffraction

On the potential for ocean acidification to be a general cause of ancient reef crises - Kießling, Wolfgang; Simpson, Carl (Global Change Biology, 2011)
Anthropogenic rise in the carbon dioxide concentration in the atmosphere leads to global warming and acidification of the oceans. Ocean acidification (OA) is harmful to many organisms but especially to those that build massive skeletons of calcium carbonate, such as reef corals. Here, we test the recent suggestion that OA leads not only to declining calcification of reef corals and reduced growth rates of reefs but may also have been a trigger of ancient reef crises and mass extinctions in the sea. We analyse the fossil record of biogenic reefs and marine organisms to (1) assess the timing and intensity of ancient reef crises, (2) check which reef crises were concurrent with inferred pulses of carbon dioxide concentrations and (3) evaluate the correlation between reef crises and mass extinctions and their selectivity in terms of inferred physiological buffering. We conclude that four of five global metazoan reef crises in the last 500 Myr were probably at least partially governed by OA and rapid global warming. However, only two of the big five mass extinctions show geological evidence of OA. © 2010 Blackwell Publishing Ltd.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LP.onthep
Keywords: Climate change; Mass extinctions; Ocean acidification; Phanerozoic; Reefs

On the value of hydrochemical data for the interpretation of flow and transport processes in the Baget karst system, France - Richieri, Beatrice; Bittner, Daniel; Sivelle, Vianney; Hartmann, Andreas; Labat, David; Chiogna, Gabriele (Hydrogeology Journal, 2024)
Continuous hourly time series of hydrochemical data can provide insights into the subsurface dynamics and main hydrological processes of karst systems. This study investigates how high-resolution hydrochemical data can be used for the verification of robust conceptual event-based karst models. To match the high temporal variability of hydrochemical data, the LuKARS 2.0 model was developed on an hourly scale. The model concept considers the interaction between the matrix and conduit components to allow a flexible conceptualization of binary karst systems characterized by a perennial spring and intermittent overflow as well as possible surface water bypassing the spring. The model was tested on the Baget karst system, France, featuring a recharge area defined by the coexistence of karst and nonkarst areas. The Morris screening method was used to investigate parameter sensitivity, and to calibrate the model according to the Kling-Gupta Efficiency (KGE). Model verification was performed by considering additional hydrochemical constraints with the aim of representing the internal dynamics of the systems, i.e., water contributions from the various compartments of the conceptual model. The hydrochemical constraints were defined based on high-temporal resolution time series of SO42− and HCO3−. The results of this study show that the simulation with the highest KGE among 9,000 model realizations well represents the dynamics of the spring discharge but not the variability of the internal fluxes. The implementation of hydrochemical constraints facilitates the identification of realizations reproducing the observed relative increase in the flow contribution from the nonkarst area.
CRIS-Team Scopus Importer:2024-06-21
Keywords: Conceptual models; France; Hydrochemistry; Karst; Rainfall-runoff

Optical dating of alluvial deposits at the orogenic front of the Andean Precordillera (Mendoza, Argentina) - Schmidt, Silke; Tsukamoto, Sumiko; Salomon, Eric; Frechen, Manfred; Hetzel, Ralf (Geochronometria, 2012)
Well constrained numerical ages of alluvial fan sediments are key to understanding the chronology of alluvial episodes and tectonic activity at the front of the Andean Precordillera. We tested the application of radiocarbon and optically stimulated luminescence (OSL) dating in the distal part of an alluvial fan five kilometers north of Mendoza. For OSL dating a large number of aliquots (n > 70) - each composed of similar to 50 quartz grains - were measured in order to obtain reliable burial ages despite scattered dose distributions. Owing to a feldspar contamination in all samples, an infrared stimulation was inserted before each OSL measurement, which reduced the feldspar OSL signal successfully. By using the minimum age model we obtained stratigraphically consistent burial ages of alluvial deposits in a depth profile. The uppermost similar to 1 m of sediment is composed of debris flow deposits buried 770 +/- 76 years ago. Three plant remnants used for radiocarbon dating from the same layer, however, yielded ages younger than 350 years, which are interpreted to underestimate the depositional age. Underneath the debris flow, a major unconformity cuts a series of distal alluvial fan sediments with interstratified floodplain deposits, which are composed of sandy and calciterich silt layers, respectively. Three samples from this unit which were distributed over one meter of sediment thickness yielded statistically concordant OSL ages of 12.3 +/- 1.2 ka, 12.3 +/- 1.2 ka, and 11.7 +/- 1.1 ka. The deposition of these sediments during the latest Pleistocene coincides with a phase of cool and humid climate, which occurred before the alluvial fan propagated farther into the foreland. The overlying debris flow sediments are associated with alluvial fan incision during the arid Late Holocene.
Keywords: OSL dating; alluvial fan sediments; incomplete bleaching; minimum age model; Andean Precordillera

Optimization of instrument setup and post-run corrections for oxygen and hydrogen stable isotope measurements of water by isotope ratio infrared spectroscopy (IRIS) - van Geldern, Robert; Barth, Johannes (Limnology and Oceanography-Methods, 2012)

Optimizing sampling approaches along ecological gradients - Schweiger, Andreas H.; Irl, Severin D. H.; Steinbauer, Manuel; Dengler, Juergen; Beierkuhnlein, Carl (Methods in Ecology and Evolution, 2016)
Natural scientists and especially ecologists use manipulative experiments or field observations along gradients to differentiate patterns driven by processes from those caused by random noise. A well-conceived sampling design is essential for identifying, analysing and reporting underlying patterns in a statistically solid and reproducible manner, given the normal restrictions in labour, time and money. However, a technical guideline about an adequate sampling design to maximize prediction success under restricted resources is lacking. This study aims at developing such a solid and reproducible guideline for sampling along gradients in all fields of ecology and science in general. We conducted simulations with artificial data for five common response types known in ecology, each represented by a simple function (no response, linear, exponential, symmetric unimodal and asymmetric unimodal). In the simulations, we accounted for different levels of random and systematic error, the two sources of noise in ecological data. We quantified prediction success for varying total sample size, number of locations sampled along a spatial/temporal gradient and number of replicates per sampled location. The number of replicates becomes more important with increasing random error, whereas replicates become less relevant for a systematic error bigger than 20% of total variation. Thus, if high levels of systematic error are indicated or expected (e.g. in field studies with spatial autocorrelation, unaccountable additional environmental drivers or population clustering), continuous sampling with little to no replication is recommended. In contrast, sampling designs with replications are recommended in studies that can control for systematic errors. In a setting that is characteristic for ecological experiments and field studies strictly controlling for undeterminable systematic error (random error ≥10% and systematic error ≤10% of total variation), prediction success was best for an intermediate number of sampled locations along the gradient (10–15) and a low number of replicates per location (3). Our findings from reproducible, statistical simulations will help design appropriate and efficient sampling approaches and avoid erroneous conclusions based on studies with flawed sampling design, which is currently one of the main targets of public criticism against science.
Keywords: ANOVA; Curve fitting; Ecological experiment; Experimental design; Model selection; Regression analysis; Replication; Sampling design; Simulation

Orbit size and estimated eye size in dinosaurs and other archosaurs and their implications for the evolution of visual capabilities - Lautenschlager, Stephan; Aston, Rune F.; Baron, Jessica L.; Boyd, John R.; Bridger, Harold W.L.; Carmona, Victor E.T.; Ducrey, Thomas; Eccles, Olive; Gall, Morgan; Jones, Spencer A.; Laker-Mchugh, Henry; Lawrenson, Daniel J.; et al. (Journal of Vertebrate Paleontology, 2023)
Vision is one of the most important senses for animals, allowing them to interact with their environment and with further implications for evolutionary histories. However, relevant soft tissues, such as the eye and associated structures, are not preserved in fossil vertebrates, limiting our knowledge of their visual capabilities. Here, we quantified absolute and relative orbit size for 400 species of dinosaurs and other extinct archosaurs using linear measurements of the preserved skeletal elements as a proxy for visual capabilities. Our results demonstrate that the orbit makes up on average 20% of skull size with a strong and consistent correlation across all sampled groups. This trend is largely independent of temporal distribution, species richness, and phylogeny. In fact, relative orbit size is narrowly constrained and did not surpass 45% of skull size, suggesting physiological and functional controls. Estimated eye size was found to be absolutely larger in herbivores, whereas carnivores tended to have smaller eyes absolutely and compared with skull size. Relatively large eyes only occurred in small-bodied species and vice versa. However, eye size alone was not sufficient to discriminate between different activity patterns or to characterize visual capabilities in detail.
CRIS-Team Scopus Importer:2024-12-16

Ordination analysis in sedimentology, geochemistry and palaeoenvironment-Background, current trends and recommendations - Bialik, Or M.; Jarochowska, Emilia; Grossowicz, Michal (Depositional Record, 2021)
Ordination is the name given to a group of methods used to analyse multiple variables without preceding hypotheses. Over the last few decades, the use of these methods in Earth science in general, and notably in analyses of sedimentary sources, has dramatically increased. However, with limited resources oriented towards Earth scientists on the topic, the application of ordination analysis is at times suboptimal and misuse by authors can occur. This text was written for researchers with little to no experience with ordination with the aim of exposing them to the utility and the pitfalls of this branch of exploratory statistics. To do so, a detailed review of three ordination methods is offered: principal component analysis, non-metric multidimensional scaling and detrended correspondence analysis. A survey of 163 publications in Earth science is presented, in which these ordination methods were used together with a summary of how, why and on what type of data ordination was used. With common mistakes outlined and misuses in those publications identified. Notably, issues were found with reproducibility, documentation, data set dimensions and transformations. Based on this survey, a recommended workflow is offered for Earth scientists who wish to apply ordination. Additionally, this article is accompanied by highly annotated R scripts for novice users to use these methods.
CRIS-Team WoS Importer:2021-09-24

Ordovician and Silurian sea-water chemistry, sea level, and climate: A synopsis - Munnecke, Axel; Calner, Michael; Harper, David A.T.; Servais, Thomas (Palaeogeography, Palaeoclimatology, Palaeoecology, 2010)
Following the Cambrian Explosion and the appearance in the fossil record of most animal phyla associated with a range of new body plans, the Ordovician and Silurian periods witnessed three subsequent major biotic events: the Great Ordovician Biodiversification Event, the end-Ordovician extinction (the first animal extinction and second largest of the five mass extinctions of the Phanerozoic), and the Early Silurian post-extinction recovery. There are currently no simple explanations for these three major events. Combined extrinsic (geological) and intrinsic (biological) factors probably drove the biodiversifications and radiations, and the appearance and disappearance of marine habitats have to be analysed in the frame of changing palaeogeography, palaeoclimate and sea-water chemistry. The present paper reviews the relationships of the three biotic events to chemical and physical processes occurring in the ocean and atmosphere during the Ordovician and Silurian, including sea-level changes, geochemical proxies (δC, δO, Sr/Sr) of the ocean waters, and the evolution of the atmosphere (oxygen and carbon dioxide content). © 2010 Elsevier B.
Keywords: Climate; Ordovician; Sea level; Silurian; Stable isotopes

Ordovician paleokarst, quartz sand and climate - Keller, Martin; Lehnert, Oliver (Palaeogeography, Palaeoclimatology, Palaeoecology, 2010)
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LG.ordovi

Ordovician stable carbon isotope stratigraphy in the Tarim Basin, NW China - Zhang, Yuandong; Munnecke, Axel (Palaeogeography, Palaeoclimatology, Palaeoecology, 2016)
The Tarim Basin, located in NW-China, represents one of China's major palaeoplates. Its palaeogeographic position in the Ordovician, however, is debated. In this study we present biostratigraphically controlled stable carbon isotope data from some 600 samples spanning almost the entire Ordovician in order to provide a tool that can be used for future chemostratigraphic correlations. The data correlate well with results from South China, and several major global δC excursions such as the MDICE (Dw2/3), SAICE (Sa2), GICE (Ka1), and Whitewater excursion (Ka4) are documented for the first time from the Tarim Basin. Major sedimentary gaps are detected in the lower Floian between the Penglaiba and Yinshan formations, in the upper Darriwilian to lower Sandbian between the Dawangou and Saergan (or Kanling) formations, and in the latest Sandbian between the Kanling and Qilang formations as well as between the Tumuxiuke and Lianglitag formations. Three scenarios for the depositional history of the late Darriwilian to early Sandbian Saergan Formation, which represents an important hydrocarbon source rock in the Tarim Basin, are discussed with respect to their bio- and chemostratigraphic implications. The mid-upper Ordovician rocks recording high δC values have been deposited during transgressive or highstand intervals, whereas the regressive intervals are mostly missing. This results in a stacking of several positive excursions, and thus chemostratigraphic correlation without biostratigraphic control might produce misleading results, especially for shallow-water carbonates.
Keywords: Chemostratigraphy; Ordovician; Source rocks; Stable carbon isotope; Tarim

Ordovician stratigraphy and sedimentary facies of the Stumsnäs 1 core from the southern Siljan Ring, central Sweden. - Lehnert, Oliver; Meinhold, Guido; Arslan, Arzu; Ebbestad, Jan Ove; Calner, Mikael (Gff, 2013)
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LG.ordovi

Organic-walled microfossils incertae sedis from the Ordovician of the Argentine Precordillera and Bohemia - Heuse, Thomas; Lehnert, Oliver; Kraft, Petr (Acta Universitatis Carolinae - Geologica, 1997)

Origin, age and stratigraphic significance of distal fallout ash tuffs from the Carbonifereous-Permian continental Saar-Nahe Basin (SW-Germany) - Königer, Stephan; Lorenz, Volker; Stollhofen, Harald; Armstrong, Richard A. (International Journal of Earth Sciences, 2002)
Thin, widespread, fallout tuff layers interbedded within fluvio-lacustrine successions of the Carboniferous–Permian Saar–Nahe Basin provide important tephrostratigraphic markers. In addition, radiogeochronometric data derived from the tuffs serve as calibration points for the adjustment to regional chronostratigraphy and to numerical time scales. The Pappelberg-Tuff in the Meisenheim Formation (Glan Group) has been dated by U/Pb zircon SHRIMP technique at 297.0±3.2 Ma. Taking the Carboniferous/Permian boundary at 296 Ma, the Meisenheim Formation coincides approximately with this boundary. Consequently, underlying strata, lithostratigraphically regarded as the basal part of the ‘Rotliegend’, chronostratigraphically belong to the Upper Carboniferous. Bed thicknesses, grain size and sorting characteristics of the tuffs and the absence of contemporaneously emplaced volcanics within the Saar–Nahe Basin point to an extrabasinal derivation of the wind-drifted volcanic ash. Decreasing grain sizes of juvenile pyroclastic particles towards the north suggest source areas south of the basin within 300 km distance. The majority of the tuffs are rhyolitic to rhyodacitic and indicate petrographic and geochemical affinities to Moldanubian S-type granitoids, in particular to highly differentiated two-mica granites, and related volcanic effusives. Within the time frame considered here, such potential source rocks were emplaced in the northern and central Black Forest (SW Germany) and the northern Vosges (E France) at 100–150 km distance south of the Saar–Nahe Basin.
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.LG.origin
Keywords: Distal fallout ash tuffs · Saar–Nahe Basin · ‘Lower Rotliegend’; Glan Group; Meisenheim Formation; Variscan volcanism; SHRIMP U/Pb zircon ages; Chronostratigraphy; Carboniferous/Permian boundary

Origin and geodynamic significance of the early Mesozoic Weiya LP and HT granulites from the Chinese Eastern Tianshan - Mao, Ling-Juan; He, Zhenyu; Zhang, Zeming; Klemd, Reiner; Xiang, Hua; Tian, Zuolin; Zong, Keqing (Lithos, 2015)
The Chinese Tianshan in the southwestern part of the Central Asian Orogenic Belt (CAOB) is characterized by a variety of high-grade metamorphic rocks, which provide critical constraints for understanding the geodynamic evolution of the CAOB. In this paper, we present detailed petrological and zircon U–Pb geochronological studies of the Weiya low-pressure and high-temperature (LP-HT) granulites of the Chinese Eastern Tianshan. These granulites were previously considered to be a product of a regional metamorphic orogenic event. Due to different bulk-rock chemistries the Weiya granulites, which occur as lenses within the contact metamorphic aureole of the Weiya granitic ring complex, have a variety of felsic–pelitic and mafic granulites with different textural equilibrium mineral assemblages including garnet–cordierite–sillimanite-bearing granulites, cordierite–sillimanite-bearing granulites, cordierite–orthopyroxene-bearing granulites, and orthopyroxene–clinopyroxene-bearing granulites. Average P–T thermobarometric calculations and conventional geothermobarometry indicates that the Weiya granulites underwent early prograde metamorphism under conditions of 600–650 °C at 3.2–4.2 kbar and peak metamorphism of 750–840 °C at 2.9–6.3 kbar, indicating a rather high geothermal gradient of ca. 60 °C/km. Zircon U–Pb LA–ICP–MS dating revealed metamorphic ages between 244 ± 1 to 237 ± 3 Ma, which are in accordance with the crystallization age of the Weiya granitic ring complex. We suggest that the formation of the Weiya granulites was related to contemporaneous granitic magmatism instead of a regional metamorphic orogenic event. In addition, a Late Devonian metamorphic age of ca. 380 Ma was recorded in zircon mantle domains from two pelitic samples which is consistent with the metamorphic age of the Xingxingxia metamorphic complex in the Chinese Eastern Tianshan. This suggests that the mantle domains of the zircon grains of the Weiya granulites probably formed during the Late Devonian regional metamorphism and were overprinted by the Early Triassic contact metamorphism. Therefore, Early Triassic geodynamic models for the southwestern part of the CAOB, which are based on a previously suggested regional metamorphic orogenic event of the Weiya granulites, need to be viewed with caution.<br
Keywords: Central Asian Orogenic Belt; Chinese Eastern Tianshan; Weiya granulites; Early Triassic; Contact metamorphism; Geodynamic setting

Origination and dispersal dynamics of Cenozoic marine plankton - Raja, Nussaïbah Begum; Kießling, Wolfgang (Annual Meeting of the Paleontological Society (Paläontologische Gesellschaft) 2019, 2019)

Origin of discordant ultramafic pegmatites in the Bushveld Complex from externally-derived magmas - Cawthorn, Grant; Latypov, Rais; Klemd, Reiner; Vuthuza, Andisiwe (South African Journal of Geology, 2018)
Coarse-grained, discordant, mainly ultramafic, bodies cut the layered succession of the Bushveld Complex. Previous models have subdivided them into magnesian dunite, considered to have been emplaced upward, and more ironrich wehrlite (± oxides), referred to as iron-rich ultramafic pegmatites (IRUP), emplaced downward. We have studied a number of these IRUP bodies in an open pit on Marikana Mining Operations platinum mines property, near Rustenburg, as well as other samples from different levels in the intrusion. A compilation of our and previously published compositions for olivine and clinopyroxene suggests that there are not two discrete suites and processes, but that all bodies originated from multiple magmas with a similar source, resulting in formation of magnesian olivine followed by progressively more iron-rich olivine and clinopyroxene in a fractionating system. In fact, more evolved compositions of discordant pegmatitic gabbro mineralogy exist that have been largely ignored in the past, but are considered here to be cogenetic with the ultramafic bodies. These rocks are all cumulates, based on their simple mineralogy and extreme deficiency in incompatible trace elements in whole-rock compositions. We question the previous models. The first involved fluid replacement. We question from where the high TiO2 content of these bodies originated and to where the high Al2O3 (from the replaced plagioclase) went, noting that TiO2 and Al2O3 are typically the most refractory of oxides. The second involved highly evolved or immiscible liquids or products of disequilibrium melting, generated within the intrusion, considered to have penetrated downward (kms) displacing a succession of cumulate rocks. We question the mechanism by which a downward penetrating magma could displace pre-existing cumulates, presumably returning them back up the same conduit without any interaction between the two. We suggest that initial upward penetration of magmas, not generated within the layered succession, replaced the existing cumulates initially by infiltration. Subsequently, vertical central channels developed and large volumes of magma flowed through, precipitating cumulus minerals. The removed components and the residual liquids from formation of these discordant cumulate bodies were expelled upward. The composition of the proposed liquid for these bodies is considered to have affinities with sub-alkaline basalt (ankaramite), which occurs in many large igneous provinces, and whose distinctive features are the dominance of olivine and clinopyroxene and absence of plagioclase, and have a high CaO/Al2O3compared to tholeiitic magmas. Support for this conclusion is based in part on the clinopyroxene compositions in IRUP, which are enriched in the wollastonite component and do not plot near to the tholeiite or Bushveld trend in the pyroxenite quadrilateral. They contain no exsolution which is abundant in all layered rocks in the Bushveld Complex. Examples of such sub-alkaline rocks related to the Bushveld Complex have been previously reported. One (Schoongezicht intrusion), distal from, and at a much deeper stratigraphic level (base of the Ventersdorp Supergroup) than, the complex, is dominated by dunite, wehrlite and magnetitite, comparable to the IRU
Keywords: Africa; Bushveld Complex; chain silicates; clinopyroxene; dunite; feldspar group; framework silicates; granites; ICP mass spectra; igneous rocks; magmas; magnetite; mass spectra; mineral composition; nesosilicates; olivine group; oxides pegmatite; plutonic rocks; peridotites; plagioclase; pyroxene group; silicates; South Africa; Southern Africa; trace metals; ultramafics; wehrlite

Origin of Early Eocene diabase dikes in the southern Lhasa terrane: Implications for the Neo-Tethyan slab breakoff - Deng, Yulin; Lang, Xinghai; Klemd, Reiner; Wang, Xuhui; He, Qing; Zhou, You; Yin, Qing; Zhan, Hongyu (Lithos, 2024)
The geodynamic evolution of the Himalayan–Tibetan orogen during the transition from Neo-Tethyan oceanic to Indian continental subduction remains unclear. Therefore, we conducted a new geochronological, geochemical, and Sr–Nd–Pb–Hf isotopic study of post-collisional diabase dikes in the central segment of the southern Lhasa subterrane. The diabase dike samples yield zircon U–Pb ages of 51–49 Myr, consistent with the timing of the Gangdese magmatic flare-up (ca. 53–50 Myr). In addition, the diabase dikes exhibit a geochemical intraplate affinity and depleted Sr–Nd–Pb isotopic compositions. Their variable Nb contents allow, the dikes to be divided into low-Nb (<8 ppm) and high-Nb (>9 ppm) types, which represent the melting products of slab fluid-modified Gangdese lithospheric mantle and a mixed mantle source comprising Gangdese lithospheric and deep asthenospheric mantle, respectively. In addition, the wide variation in εHf(t) values (−10.0 to +12.3) of zircons from these diabase dikes is consistent with the Gangdese zircon Hf isotopic ‘pull-down’ at ca. 50 Ma. Integrating our new data with published results suggests that the zircon Hf isotopic ‘pull-down’ was a direct consequence of the involvement of subducted Indian continental components in the formation of the Gangdese continental lithosphere. The combined data further suggest that upwelling of the asthenosphere, triggered by breakoff of the Neo-Tethyan oceanic slab, resulted in extensive mantle and crustal melting in the Lhasa terrane and the Tethyan Himalaya in southern Tibet.
CRIS-Team Scopus Importer:2024-05-17
Keywords: Diabase dikes; Indian continental subduction; Lhasa Terrane; Slab breakoff

Origin of Erzgebirge ultrahigh-pressure garnetite: Formation from a basaltic protolith by serpentinization-assisted metasomatism? - Schmädicke, Esther; Will, Thomas M. (Journal of Metamorphic Geology, 2023)
Erzgebirge ultrahigh-pressure (UHP) garnet peridotite includes scarce layers of garnet pyroxenite, nodules of garnetite and, very rarely, of eclogite. Peridotite-hosted eclogite shows the same subalkali-basaltic bulk rock composition, mineral assemblage and peak conditions as gneiss-hosted eclogite present in the same UHP unit. Garnetite has considerably more Mg, moderately enhanced Ca and Fe and significantly lower contents of Na, Ti, P, K and Si than eclogite, whereas Al is very similar. In addition, the compatible trace elements (Ni, Co, Cr, V) are elevated and most incompatible elements (Zr, Hf, Y, Sr, Rb and rare Earth elements [REE]) are depleted in garnetite relative to eclogite. In contrast to other large ion lithophile elements (LILEs), Pb (+121%) and Ba (+83%) are strongly enriched. The REE patterns of garnetite are characterized by depletion of light and heavy REE and a medium REE hump indicative of metasomatism, features being absent in eclogite. An exceptional garnetite sample shows an REE distribution similar to that of eclogite. Garnetite is interpreted to have formed from the same, but metasomatically altered, igneous protolith as eclogite. Except for Ba and Pb, the chemical signature of garnetite is explained best by metasomatic changes of its basaltic protolith caused by serpentinization of the host peridotite. Garnetite is chemically similar to basaltic rodingite/metarodingite. Although rodingite is commonly more enriched in Ca, there are also examples with moderately enhanced Ca matching the composition of Erzgebirge garnetite. Limited Ca metasomatism is attributed to the preservation of Ca in peridotite during hydrous alteration. This can be explained by incomplete serpentinization favouring metastable survival of the original clinopyroxene. In this case, most Ca is retained in peridotite and not available for infiltration and metasomatism of the garnetite protolith. This inescapable consequence is supported by the fact that clinopyroxene is part of the garnet peridotite UHP assemblage, which would not be the case if Ca had been removed from the protolith prior to high-pressure metamorphism. The enrichment of compatible elements in garnetite is attributed to decomposition of peridotitic olivine (Ni, Co) and spinel (Cr, V) during serpentinization. Enrichment of Ba and Pb contrasts the behaviour of other LILEs and is ascribed to dehydration of the serpentinized peridotite (deserpentinization). This requires two separate stages of metasomatism: (1) intense chemical alteration of the basaltic garnetite precursor, together with serpentinization of peridotite at the ocean floor or during incipient subduction; and (2) prograde metamorphism and dehydration of serpentinite during continued subduction, thereby releasing Pb–Ba-rich fluids that reacted with associated metabasalt. Finally, subduction to >100 km and UHP metamorphism of all lithologies led to formation of garnetite, eclogite and garnet pyroxenite hosted by co-facial garnet peridotite as observed in the Erzgebirge.
CRIS-Team Scopus Importer:2023-11-17
Keywords: Erzgebirge; garnetite; rodingitization; serpentinization; UHP metamorphism

Origin of magnetic anomalies in volcaniclastic units of the Messel maar-diatreme (Germany). In Goth, K. & Suhr, P. (eds.): Geophysics of maars and diatremes - de Wall, Helga; et al. (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 2006)
UnivIS-Import:2015-03-09:Pub.2006.nat.dgeo.IGM.c3tekt.origin

Origin of particulate organic carbon in the upper St. Lawrence: Isotopic constraints - Barth, Johannes; et al. (Earth and Planetary Science Letters, 1998)

Origin of planktotrophy - evidence from early molluscs: a response to Freeman and Lundelius. - Nützel, Alexander; Lehnert, Oliver; Fryda, Jiri (Evolution & Development, 2007)
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LG.origin

Origin of planktotrophy - evidence from early molluscs - Nützel, Alexander; Lehnert, Oliver; Fryda, Jiri (Evolution & Development, 2006)
The size of early ontogenetic shells (protoconchs) of ancient benthic molluscs suggests that feeding larvae occurred at about 490 myr (approximately, transition from Cambrian to Ordovician). Most studied Ordovician protoconchs were smaller than Cambrian ones, indicating smaller Ordovician eggs and hatchlings. This suggests substitution of nutritious reserve matter such as yolk by plankton as an energy source for larvae. The observed size change represents the first direct empiric evidence for a late Cambrian to Ordovician switch to planktotrophy in invertebrate larvae. It corroborates previous hypotheses about a possible polyphyly of planktotrophy. These hypotheses were primarily based on molecular clock data of extant clades with different types of larva, change in the overall body size, as well as increasing predation pressure on Early Paleozoic sea floors. The Early Ordovician is characterized by an explosive radiation of benthic suspension feeders and it was suggested that planktotrophy would prolongate escape from benthic predation on hatchlings. This biological escalation hypothesis does not fully explain why planktotrophy and suspension feeding became important at the same time, during a major biodiversification. An additional factor that probably included availability of nutrients must have played a role. We speculate that an increasing nutrient supply and availability of photoautotrophic plankton in world oceans have facilitated both planktotrophy and suspension feeding, which does not exclude a contemporaneous predation-driven escalation. It is very likely that the evolution of planktotrophy as well as increasing predation contributed to the Ordovician radiation. © 2006 The Author(s).
UnivIS-Import:2015-03-09:Pub.2006.nat.dgeo.IGM.LP.assess_9

Origin of s-, a-and i-type granites: Petrogenetic evidence from whole rock th/u ratio variations - Regelous, Anette; Scharfenberg, Lars; de Wall, Helga (Minerals, 2021)
The origin and evolution of granites remain a matter of debate and several approaches have been made to distinguish between different granite types. Overall, granite classification schemes based on element concentrations and ratios, tectonic settings or the source rocks (I-, A-, S-type) are widely used, but so far, no systematic large-scale study on Th/U ratio variations in granites based on their source or tectonic setting has been carried out, even though these elements show very similar behavior during melting and subsequent processes. We therefore present a compiled study, demonstrating an easy approach to differentiate between S-, A-and I-type granites using Th and U concentrations and ratios measured with a portable gamma ray spectrometer. Th and U concentrations from 472 measurements in S-and I-type granites from the Variscan West-Bohemian Massif, Germany, and 78 measurements from Neoproterozoic A-type Malani granites, India, are evaluated. Our compendium shows significant differences in the average Th/U ratios of A-, I-and S-type granites and thus gives information about the source rock and can be used as an easy classification scheme. Considering all data from the studied A-, I-and S-type granites, Th/U ratios increase with rising Th concentrations. A-type granites have the highest Th/U ratios and high Th concentrations, followed by I-type granites. Th/U ratios in S-to I-type granites are lower than in A-type and I-type granites, but higher than in S-type granites. The variation of Th/U ratios in all three types of granite cannot be explained by fractional crystallization of monazite, zircon and other Th and U bearing minerals alone, but are mainly due to source heterogeneities and uranium mobilization processes.
CRIS-Team Scopus Importer:2021-07-02
Keywords: Continental crust; Granites; Petrogenesis; Thorium; Uranium

Origin of Silicic Magmas at Spreading Centres-an Example from the South East Rift, Manus Basin - Beier, Christoph; Bach, Wolfgang; Turner, Simon; Niedermeier, Dominik; Woodhead, Jon; Erzinger, Joerg; Krumm, Stefan (Journal of Petrology, 2015)
There has been much recent interest in the origin of silicic magmas at spreading centres away from any possible influence of continental crust. Here we present major and trace element data for 29 glasses (and 55 whole-rocks) sampled from a 40 km segment of the South East Rift in the Manus Basin that span the full compositional continuum from basalt to rhyolite (50-75 wt % SiO2). The glass data are accompanied by Sr-Nd-Pb, O and U-Th-Ra isotope data for selected samples. These overlap the ranges for published data from this part of the Manus Basin. Limited increases in Cl/K ratios with increasing SiO2, La-SiO2 and Yb-SiO2 relationships, and the oxygen isotope data rule out models in which the more silicic lavas result from partial melting of altered oceanic crust or altered oceanic gab-bros. Rather, the data form a coherent array that is suggestive of closed-system fractional crystallization and this is well simulated by MELTS models run at 0.2 GPa and QFM (quartz-fayalite-magnetite buffer) with 1 wt % H2O, using a parental magma chosen from the basaltic glasses. Although some assimilation of altered oceanic crust or gabbro cannot be completely ruled out, there is no evidence that this plays an important role in the origin of the silicic lavas. The U-series disequilibria are dominated by U-238 and Ra-226 excesses that limit the timescale of differentiation to less than a few millennia. Overall, the data point to rapid evolution in relatively small magma lenses located near the base of thick oceanic crust; we speculate that this was coupled with relatively low rates of basaltic recharge. A similar model may be applicable to the generation of silicic magmas elsewhere in the ocean basins.
Keywords: silicic lavas; differentiation; oceanic spreading centre; South East Rift; Manus Basin

Origin of the Cretaceous olistostromes in the Oman mountains (Sultanate of Oman): Evidence from clay minerals - Mattern, Frank; Scharf, Andreas; Pracejus, Bernhard; Al Shibli, Issa S. A.; Al Kabani, Bader M. S.; Al Qasmi, Waleed Y. A.; Kießling, Wolfgang; Callegari, Ivan (Journal of African Earth Sciences, 2022)
Mid- to Late Cretaceous olistostrome generation ensued sequentially, linked to progressive southwest-directed thrusting of the Semail Ophiolite towards and over Arabia - at first in the northeastern part of the oceanic Hawasina Basin (Umar Sub-Basin) and then in its southwestern part (Hamrat Duru-Sub-Basin). Thrusting steepened slopes, causing seismic tremors, which destabilized slope sediments and triggering olistostrome formation. Ophiolite thrusting over Arabia created the Aruma Foreland Basin. Olistostrome formation in the foredeep ensued last and on the flank of the uplifting forebulge. As olistoliths, Olistostrome 1 contains radiolarian limestone, plain micrite, allodapic limestone, basalt, amygdaloidal basalt, radiolarian chert and coarse, massive limestone with crystalline texture (Oman Exotics). These olistoliths "float" in shale, containing illite/muscovite, vermiculite and kaolinite. Olistostrome 1 formed in the Umar Sub-Basin. Olistostrome 2 is associated with the Late Albian to Coniacian Nayid Formation of the Hamrat Duru Sub-Basin. It is characterized by olistoliths of graded limestones (calc-turbidites) with angular shelfal limestone lithoclasts. The olistoliths are embedded in shale with unidentifiable clay minerals. Olistostrome 2 formed in the Hamrat Duru Sub-Basin, postdating Olistostrome 1. Olistostrome 3 is associated with the Upper Cretaceous Aruma Foreland Basin and characterized by olistoliths, like lithoclastic packstone (calcarenite), dolomitic limestone, and sandstone with carbonate lithoclasts. The matrix of the olistoliths is a pyrophyllite- and kaolinite-bearing shale. Olistostrome 3 formed in the foredeep as the youngest olistostrome. The different clay mineralogy of Olistostrome 1 and Olistostrome 3, reflects their different basinal origin. Shale samples taken from conventional sediments (no olistostromes) of the syn-tectonic and post-tectonic Aruma units show some resemblance in their clay mineralogy as they contain detritus from the Oman Mountains. Olistolith types of both Hawasina olistostromes differ significantly. The reviewed and novel data may serve as a guideline for future olistostrome studies in the Oman Mountains and may be particularly helpful in identifying the basinal origin of olistostromes in case of fault-bounded olistostromes, unexposed olistostrome contacts and inconclusive olistoliths. Evaluating matrix shales of olistostromes leads to important decision criteria, such as color, oxygenation state and clay mineralogy, to determine the paleogeographic basin position.
CRIS-Team WoS Importer:2022-06-24

Osmium and lithium isotope evidence for weathering feedbacks linked to orbitally paced organic carbon burial and Silurian glaciations - Sproson, Adam D.; Pogge von Strandmann, Philip A.E.; Selby, David; Jarochowska, Emilia; Frýda, Jiří; Hladil, Jindřich; Loydell, David K.; Slavík, Ladislav; Calner, Mikael; Maier, Georg; Munnecke, Axel; Lenton, Timothy M. (Earth and Planetary Science Letters, 2022)
The Ordovician (∼487 to 443 Ma) ended with the formation of extensive Southern Hemisphere ice sheets, known as the Hirnantian glaciation, and the second largest mass extinction in Earth History. It was followed by the Silurian (∼443 to 419 Ma), one of the most climatically unstable periods of the Phanerozoic as evidenced by several large scale (>5‰) carbon isotope (δ13C) perturbations associated with further extinction events. Despite several decades of research, the cause of these environmental instabilities remains enigmatic. Here, we provide osmium (187Os/188Os) and lithium (δ7Li) isotope measurements of marine sedimentary rocks that cover four Silurian δ13C excursions. Osmium and Li isotope records resemble those previously recorded for the Hirnantian glaciation suggesting a similar causal mechanism. When combined with a new dynamic carbon-osmium-lithium biogeochemical model we suggest that astronomical forcing of the marine organic carbon cycle, as opposed to a decline in volcanic arc degassing or the rise of early land plants, resulted in drawdown of atmospheric CO2, triggering continental scale glaciation, intense global cooling and eustatic sea-level lows recognised in the geological record. Lower atmospheric pCO2 and temperatures during the Hirnantian and Silurian glaciations suppressed CO2 removal by silicate weathering, driving 187Os/188Os and δ7Li variability, supporting the existence of climate-regulating feedbacks.
CRIS-Team Scopus Importer:2021-11-12
Keywords: eccentricity and precession; Hirnantian glaciation; orbital obliquity; osmium (; silicate weathering; Silurian palaeoclimate

Osteogenic lithium-doped brushite cements for bone regeneration - Hurle, Katrin; Maia, F. R.; Ribeiro, V. P.; Pina, S.; Oliveira, J. M.; Götz-Neunhoeffer, Friedlinde; Reis, R. L. (Bioactive Materials, 2022)
This study investigated the osteogenic performance of new brushite cements obtained from Li+-doped β-tricalcium phosphate as a promising strategy for bone regeneration. Lithium (Li+) is a promising trace element to encourage the migration and proliferation of adipose-derived stem cells (hASCs) and the osteogenic differentiation-related gene expression, essential for osteogenesis. In-situ X-ray diffraction (XRD) and in-situ 1H nuclear magnetic resonance (1H NMR) measurements proved the precipitation of brushite, as main phase, and monetite, indicating that Li+ favored the formation of monetite under certain conditions. Li+ was detected in the remaining pore solution in significant amounts after the completion of hydration. Isothermal calorimetry results showed an accelerating effect of Li+, especially for low concentration of the setting retarder (phytic acid). A decrease of initial and final setting times with increasing amount of Li+ was detected and setting times could be well adjusted by varying the setting retarder concentration. The cements presented compressive mechanical strength within the ranges reported for cancellous bone. In vitro assays using hASCs showed normal metabolic and proliferative levels. The immunodetection and gene expression profile of osteogenic-related markers highlight the incorporation of Li+ for increasing the in vivo bone density. The osteogenic potential of Li-doped brushite cements may be recommended for further research on bone defect repair strategies.
CRIS-Team Scopus Importer:2022-01-21
Keywords: Alkaline phosphatase activity; Bone regeneration; Brushite cements; Collagen expression; Lithium doping; Osteogenic expression; β-tricalcium phosphate

Osteological revision of the holotype of the Middle Jurassic sauropod dinosaur Patagosaurus fariasi Bonaparte, 1979 (Sauropoda: Cetiosauridae) - Holwerda, Femke Marleen; Rauhut, Oliver W. M.; Pol, Diego (Geodiversitas, 2021)
Middle Jurassic sauropod taxa are poorly known, due to a stratigraphic bias of localities yielding body fossils. One such locality is Cerro Condor North, Canadon Asfalto Formation, Patagonia, Argentina, dated to latest Early-Middle Jurassic. From this locality, the holotype of Patagosaurus fariasi Bonaparte 1986 is revised. The material consists of the axial skeleton, the pelvic girdle, and the right femur. Patagosaurus is mainly characterised by a combination of features mainly identified on the axial skeleton, including the following: 1) cervical centra with low Elongation Index; 2) high projection of the postzygodiapophyseal lamina; 3) deep anterior pleurocoels that are sometimes compartmentalized in cervicals; 4) high projection of the neural arch and spine in dorsal vertebrae and anterior(most) caudal vertebrae; 5) deep pneumatic foramina in posterior dorsals which connect into an internal pneumatic chamber, and 6) anterior caudal vertebrae with 'saddle' shaped neural spines. Diagnostic features on the appendicular skeleton include: 1) a transversely wide and anteroposteriorly short femur; 2) a medial placement of the fourth trochanter on the femur; and 3) an anteroposteriorly elongated ilium with a rounded dorsal rim, with hook-shaped anterior lobe. The characters that are diagnostic for Patagosaurus are discussed, and the osteology of Patagosaurus is compared to that of Early and Middle Jurassic (eu)sauropods from both Laurasia and Gondwana.
CRIS-Team WoS Importer:2021-10-01

Ostracod eye size: A taxonomy-free indicator of the Paleocene-Eocene Thermal Maximum sea level - Tian, Skye Yunshu; Yasuhara, Moriaki; Robinson, Marci M.; Huang, Huai-Hsuan (Marine Micropaleontology, 2021)
Deep-time sea-level changes associated with the Paleocene-Eocene Thermal Maximum (PETM) are of great interest to paleoceanographers and paleontologists, especially in shallow marine settings, like the Atlantic Coastal Plain PETM sections of the Eastern North American Continental Shelf. Accurate paleo-water depth reconstruction is essential to properly interpret and contextualize any PETM-associated paleoceanographic and paleoecological changes that are depth-dependent. In addition, our understanding on eustatic sea-level changes in the greenhouse world without polar ice sheets remains limited. Despite this importance of an accurate and robust paleodepth reconstruction, all water depth estimation methods applied for the shallow marine PETM sections suffer from uncertainties and intrinsic/logical flaws. It is therefore important to develop and apply an independent water depth proxy to complement and validate paleodepth estimates derived from the traditional estimation methods based on sedimentary fossil components and lithological features. Here we present the relative eye size of sighted ostracods as a taxonomy-free water depth proxy and apply it to shallow-marine PETM paleodepth reconstruction of the Mattawoman Creek-Billingsley Road (MCBR) core in Maryland, eastern USA. We identified a significant and rapid reduction in water depth of 40 m within the carbon isotope excursion (CIE) onset consistent with the previous estimation based on benthic foraminifer species associations. This ostracod-eye-based paleodepth reconstruction improves current understanding on the regional paleobathymetry of the Salisbury Embayment and facilitates future studies on continental shelf paleoceanography and paleoecology during the PETM, a rapid, extreme global warming event under long-term greenhouse conditions, which possibly parallels the ongoing anthropogenic warming.
CRIS-Team Scopus Importer:2021-06-11
Keywords: Ostracod relative eye size; Paleocene-Eocene Thermal Maximum; Paleodepth reconstruction; Salisbury Embayment

Outcrop scale mixing enhanced by permeability variations: the role of stationary and travelling waves of high saturation indices - Köhn, Daniel; Kelka, Ulrich; Toussaint, Renaud; Siegel, Coralie; Mullen, Gary; Boyce, Adrian; Piazolo, Sandra (Geological Magazine, 2022)
To study the ore mineralization at the outcrop scale we merge an advection-diffusion simulation with the geochemical software iphreeqc to model the mixing of two realistic fluids. We simulate the infiltration of a metal-rich fluid into a rock that is saturated with pore fluid. We test the feedback effects with a number of scenarios based on an outcrop-scale 5 x 5 m model consisting of two high-permeable vertical faults within a low-permeable host rock that lead into a permeable layer. The hot metal-rich fluid enters the model through the faults from below. We solve the advection-diffusion equation for 12 chemical species and temperature, and use iphreeqc to determine the resulting properties of local fluid domains as well as related saturation indices for minerals. The faults in the model act as pathways for the metal-rich fluid, with the infiltrating fluid displacing the pore fluid. Mixing in the model takes place as a function of advection along permeable faults coupled with diffusion of chemical species at the interface between two fluids, while heat diffusion is fast enough (10(3) times faster) to equilibrate temperature. Simulations show a high saturation index of mixing-derived minerals such as barite at the interface between the two fluids as a result of fluid mixing. Fast fluid pathways (i.e. faults) show travelling waves of high saturation indices of barite, while low-permeability zones such as fault walls and areas below less permeable layers experience stationary waves of high saturation indices. Our results show that, depending on the dominant transport process (advection or diffusion), mineralization will localize next to permeability contrasts in zones where local diffusion dominates.
CRIS-Team WoS Importer:2022-11-11

Out of the extratropics: the evolution of the latitudinal diversity gradient of Cenozoic marine plankton - Raja, Nussaïbah Begum; Kießling, Wolfgang (Proceedings of the Royal Society of London, Series B: Biological Sciences, 2021)
Many ecological and evolutionary hypotheses have been proposed to explain the latitudinal diversity gradient, i.e. the increase in species richness from the poles to the tropics. Among the evolutionary hypotheses, the ‘out of the tropics’ (OTT) hypothesis has received considerable attention. The OTT posits that the tropics are both a cradle and source of biodiversity for extratropical regions. To test the generality of the OTT hypothesis, we explored the spatial biodiversity dynamics of unicellular marine plankton over the Cenozoic era (the last 66 Myr). We find large-scale climatic changes during the Cenozoic shaped the diversification and dispersal of marine plankton. Origination was generally more likely in the extratropics and net dispersal was towards the tropics rather than in the opposite direction, especially during the warmer climates of the early Cenozoic. Although migration proportions varied among major plankton groups and climate phases, we provide evidence that the extratropics were a source of tropical microplankton biodiversity over the last 66 Myr.<br
Keywords: macroevolution; biodiversity; marine plankton; climate change; biogeography

Overcoming the coupled climate and biodiversity crises and their societal impacts - Pörtner, H. O.; Scholes, R. J.; Arneth, A.; Barnes, D. K.A.; Burrows, M. T.; Diamond, S. E.; Duarte, C. M.; Kießling, Wolfgang; Leadley, P.; Managi, S.; McElwee, P.; Midgley, G.; et al. (Science, 2023)
Earth's biodiversity and human societies face pollution, overconsumption of natural resources, urbanization, demographic shifts, social and economic inequalities, and habitat loss, many of which are exacerbated by climate change. Here, we review links among climate, biodiversity, and society and develop a roadmap toward sustainability. These include limiting warming to 1.5°C and effectively conserving and restoring functional ecosystems on 30 to 50% of land, freshwater, and ocean "scapes." We envision a mosaic of interconnected protected and shared spaces, including intensively used spaces, to strengthen self-sustaining biodiversity, the capacity of people and nature to adapt to and mitigate climate change, and nature's contributions to people. Fostering interlinked human, ecosystem, and planetary health for a livable future urgently requires bold implementation of transformative policy interventions through interconnected institutions, governance, and social systems from local to global levels.
CRIS-Team Scopus Importer:2023-04-28

Overpressure Prediction and its implications for well planning in the Bavarian Foreland Molasse Basin. - Drews, Michael; Bauer, Wolfgang (Praxisforum Geothermie.Bayern 2017, 2017)

Oversimplification risks too much: A response to 'How predictable are mass extinction events?' - Reddin, Carl J.; Aberhan, Martin; Dimitrijević, Danijela; Dowding, Elizabeth; Kocsis, Ádám; Mathes, Gregor; Nätscher, Paulina; Patzkowsky, Mark E.; Kießling, Wolfgang (Royal Society Open Science, 2023)
CRIS-Team Scopus Importer:2023-09-15

Oxide Minerals - Nadoll, Patrick (Encyclopedia of Geochemistry - A Comprehensive Reference Source on the Chemistry of the Earth, 2018)
CRIS-Team WoS Importer:2019-07-30

Oxygen and carbon stable isotope records of the Lochkovian-Pragian boundary interval from the Prague Basin (Lower Devonian, Czech Republic) - Weinerová, Hedvika; Bábek, Ondřej; Slavík, Ladislav; Vonhof, Hubert; Joachimski, Michael; Hladil, Jindřich (Palaeogeography, Palaeoclimatology, Palaeoecology, 2020)
Climate changes close to the Lochkovian-Pragian Event are still widely discussed. Carbonate δ18O and δ13C and conodont apatite δ18O from medial to distal carbonate ramp sediments were analysed to provide further stable isotope data from the stratotype area in the Prague Basin. The uppermost Silurian to lower Emsian δ18O trends are put into an updated conodont biostratigraphy framework. Carbonate δ18O and δ13C are discussed in the context of facies-dependent diagenesis. The δ13C pattern measured from different sections enables the correlation of intervals with development of different facies inside the Prague Basin. Positive δ13C shifts are often coupled with trends of decreasing computed gamma-ray (CGR) values interpreted as regressions, whereas negative δ13C shifts commonly coincide with opposite trends in CGR. The Lochkovian-Pragian boundary interval coincided with an increase in carbonate δ13C and an increase in the δ18O of conodont apatite and carbonate, which we interpret as consequence of climate cooling. Generally, the Lochkovian was warmer than the Pragian and earliest Emsian.
CRIS-Team Scopus Importer:2020-10-09
Keywords: Barrandian area; Carbonate; Climate changes; Conodont apatite; Diagenesis; Palaeozoic

Oxygen and hydrogen stable isotopes in Earth’s hydrologic cycle - van Geldern, Robert; Barth, Johannes (Isotopic Landscapes in Bioarchaeology, 2016)

Oxygen and stable carbon isotopes from a nautiloid from the middle Pennsylvanian (Late Carboniferous) impregnation Lagerstätte "Buckhorn Asphalt Quarry" - Primary paleo-environmental signals versus diagenesis - Seuß, Barbara; Titschack, Jürgen; Seifert, Severin; Neubauer, Jürgen; Nützel, Alexander (Palaeogeography, Palaeoclimatology, Palaeoecology, 2012)

Oxygen and strontium isotopes from fossil shark teeth: environmental and ecological implications for Late Palaeozoic European basins. - Fischer, Jan; Schneider, Joerg W.; Voigt, Silke; Joachimski, Michael; Tichomirowa, Marion; Tuetken, Thomas; Goetze, Jens; Berner, Ulrich (Chemical Geology, 2013)
Fossil shark remains occur in both marine and nonmarine Late Palaeozoic deposits, therefore their palaeoecology is controversial. The oxygen and strontium isotopic composition of biogenic fluorapatite in 179 teeth, scales and spines predominantly of hybodontid (Lissodus) and xenacanthiform (Orthacanthus, Xenacanthus, Bohemiacanthus, Triodus) sharks from various Late Carboniferous (Moscovian) to Early Permian (Artinskian) basins of Europe are used as ecological tracers to decipher diadromous or obligate freshwater lifestyle of the investigated taxa. The δ18OP values of the different shark teeth range from 11.7 to 20.2‰ within the different basins with mean values of 16.9±0.5‰ for the Bohemian Massif, 16.2±0.8‰ for eastern Germany, 18.2±1.0‰ for southwestern Germany, 18.5±0.7‰ for southern-central Spain, 17.6±0.4‰ for Sardinia, and 16.6±0.5‰ VSMOW for the French Massif Central. The tooth δ18OP values from the basins are mostly depleted by 1-5‰ relative to those of shark teeth from contemporaneous marine settings. Oxygen isotope signatures of co-occurring taxa do not show systematic differences excluding habitat effects for different shark groups. However, distinctly higher δ18OP values from Puertollano and Saar-Nahe can be attributed to significant evaporative enrichment in 18O of the ambient water in the ancient lacustrine environments due to a warm and dry climate and sufficient residence time in the basins. The strontium isotopic composition of the teeth varies between 0.70824 and 0.71216 with a mean value of 0.71031. These 87Sr/86Sr ratios are always more radiogenic in comparison to the 87Sr/86Sr record of seawater of their stratigraphic age. Overall, the investigated tooth samples yield low δ18OP and high 87Sr/86Sr values deviating from bioapatite values expected for contemporaneous marine vertebrates and typical for freshwater settings. This indicates a fully freshwater adapted lifestyle for a variety of fossil shark taxa in Late Palaeozoic European basins. © 2013 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LG.oxygen
Keywords: Bioapatite; Carboniferous; Freshwater shark; Oxygen isotopes; Permian; Strontium isotopes

Oxygen isotope and trace element compositions of platiniferous dunite pipes of the Bushveld Complex, South Africa - Signals from a recycled mantle component? - Günther, Thomas; Haase, Karsten; Junge, Malte; Oberthür, Thomas; Wölki, Dominic; Krumm, Stefan (Lithos, 2018)
Platiniferous dunite pipes occur in the lower mafic/ultramafic portion of the Rustenburg layered Suite of the Bushveld large igneous province (LIP). Olivine compositions in these pipes range from forsterite (Fo) 80 to 35 mol% and suggest crystallization from variably evolved magmas at high temperatures (similar to 1200 degrees C). The most primitive olivines are from a stock unit and have the highest contents of Ni (>0.15 wt%) and lowest contents of Mn (<0.3 wt%). Fractional crystallization and partial melting of pyroxenite host rock play a significant role in the formation of the fayalitic olivines with its high Mn contents (>0.3 wt%). High delta O-18 values of olivine (5.7-7.0 parts per thousand) and pyroxene (6.7-7.4 parts per thousand) are akin to those of the Lower and Critical Zone of the Bushveld intrusion suggesting a common origin. The constant high O isotope ratios with variable Fo contents in the olivines are unlike trends observed in olivine phenocrysts in magmas forming by assimilation-fractional crystallization. We suggest that the high delta O-18 in the most primitive dunites reflect that of the primary melt of the Bushveld pipes, indicating either a bulk assimilation of crust prior to pipe formation or a contribution from recycled oceanic crust in the subcontinental lithospheric mantle (SCLM). The latter scenario is supported by the high Ni/Mn ratios in primitive pipe olivine that might be inherited from melting of a pyroxene-rich mantle source. (C) 2018 Elsevier B.V. All rights reserved.
Keywords: Bushveld Complex; Kaapyaal Craton; Large Igneous Province; Olivine; Trace elements; Oxygen isotopes

Oxygen isotope and trace element compositions of platiniferous dunite pipes of the Bushveld Complex, South Africa – Signals from a recycled mantle component? - Günther, Thomas; Haase, Karsten; Junge, Malte; Oberthür, Thomas; Wölki, Dominic; Krumm, Stefan (Lithos, 2018)

Oxygen isotope evidence for the formation of andesitic-dacitic magmas from the fast-spreading Pacific-Antarctic Rise by assimilation-fractional crystallisation - Freund, Sarah; Beier, Christoph; Krumm, Stefan; Haase, Karsten (Chemical Geology, 2013)
Andesitic to dacitic lavas occur along a 300km long portion of the Pacific-Antarctic Rise close to the intersection of the spreading axis with the Foundation seamount chain. The fresh silicic glasses have low δO isotope values between 5.6‰ and 5.1‰ whereas basaltic glasses from the same ridge section have normal MORB δO values. Additionally, two FeTi basaltic and all silicic glasses have high Cl (up to 1.1wt.%) and KO (up to 1.6wt.%) contents, indicating assimilation of hydrothermally altered material. Modelling suggests that the fractionating magma assimilated up to 30% of hydrothermally altered material after 57% fractional crystallisation of the basaltic magma in a melt lens at less than 2km depth. In contrast, the basaltic glasses show little assimilation and clinopyroxene-melt barometry indicates crystal fractionation in deeper melt sills. Relatively low HO/Ce and Li/Ce ratios as well as the low δO values and high Cl and K concentrations in the silicic glasses suggest assimilation of altered crustal rock rather than a brine. While some of the variability in highly incompatible element ratios is best explained by crystal fractionation processes of FeTi-oxides (e.g., decreasing Nb/U) others require a reaction of the melt with residual amphibole and clinopyroxene (Cl/K, Tb/Yb, Hf/Sm, Ce/Yb). The initial onset of FeTi oxide crystallisation is associated with a reduced oxygen fugacity causing sulphide saturation and significant loss of S, Cu, and Co from the evolved melts. This change to more reducing melts as a result of oxide crystallisation is supported by the strong development of a negative Eu anomaly in the andesites and dacites indicating stronger partitioning of Eu into plagioclase. Reverse mineral zoning in the evolved lavas also indicates that replenishment by mafic melts occurs in the shallow melt lens. © 2013 Elsevier B.V.
Keywords: Assimilation-fractional crystallisation; FeTi basalt; Magma evolution; Mid-ocean ridge; Oxygen isotopes; Silica-rich lava

Oxygen isotope evidence for the formation of silicic Kermadec island arc and Havre-Lau backarc magmas by fractional crystallization. - Haase, Karsten; Krumm, Stefan; Regelous, Marcel; Joachimski, Michael (Earth and Planetary Science Letters, 2011)
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LG.oxygen

Oxygen isotope evolution of biogenic calcite and apatite during the Middle and Late Devonian - Joachimski, Michael; Geldern, Robert; Breisig, Stephan; Buggisch, Walter; Day, Jed; van Geldern, Robert (International Journal of Earth Sciences, 2004)
Oxygen isotope ratios of well-preserved brachiopod calcite and conodont apatite were used to reconstruct the palaeotemperature history of the Middle and Late Devonian. By assuming an oxygen isotopic composition of -1‰ V-SMOW for Devonian seawater, the oxygen isotope values of Eifelian and early Givetian brachiopods and conodonts give average palaeotemperatures ranging from 22 to 25 °C. Late Givetian and Frasnian palaeotemperatures calculated from δO values of conodont apatite are close to 25 °C in the early Frasnian and increase to 32 °C in the latest Frasnian and early Famennian. Oxygen isotope ratios of late Givetian and Frasnian brachiopods are significantly lower than equilibrium values calculated from conodont apatite δO values and give unrealistically warm temperatures ranging from 30 to 40 °C. Diagenetic recrystallization of shell calcite, different habitats of conodonts and brachiopods, as well as non-equilibrium fractionation processes during the precipitation of brachiopod calcite cannot explain the O depletion of brachiopod calcite. Moreover, the O depletion of brachiopod calcite with respect to equilibrium δO values calculated from conodont apatite is too large to be explained by a change in seawater pH that might have influenced the oxygen isotopic composition of brachiopod calcite. The realistic palaeotemperatures derived from δO may suggest that biogenic apatite records the oxygen isotopic composition and palaeotemperature of Palaeozoic oceans more faithfully than brachiopod calcite, and do not support the hypothesis that the O/O ratio of Devonian seawater was significantly different from that of the modern ocean. © Springer-Verlag 2004.
Keywords: Brachiopod calcite; Conodont apatite; Devonian; Oxygen isotopes; Palaeotemperature

Oxygen Isotope fractionation in marine aragonite of coralline sponges. - Joachimski, Michael; et al. (Geochimica Et Cosmochimica Acta, 2000)
Oxygen isotope values of the extant Caribbean coralline sponge Ceratoporella nicholsoni are compared with published temperatures and δ18O of water calculated from salinities. The measured values from aragonitic sponge skeletons have a mean offset of 1.0 ± 0.1‰ from calculated calcite equilibrium values (α(aragonite-calcite) = 1.0010). This is in good agreement with published values from synthetic aragonite. They further agree with published near-equilibrium oxygen isotope values of temperate and cold water molluscs and foraminifera extrapolated to the temperature range of the coralline sponges. These results and the mode of skeleton formation of Ceratoporella nicholsoni suggest that these sponges precipitate aragonite close to isotopic equilibrium. The temperature dependence of oxygen isotopic fractionation between the aragonite of Ceratoporella nicholsoni and water is only roughly constrained by the available data, due to the narrow temperature range of the Caribbean reef sites. However, as the data suggest oxygen isotopic equilibrium, we can calculate a well constrained temperature equation combining temperate and cold water equilibrium values from molluscs and foraminifera with our sponge data: 103lnα(aragonite-water) = (18.45 ± 0.4) * 103/T(K) - (32.54 ± 1.5) and T (°C) = (20.0 ± 0.2) - (4.42 ± 0.10) * (δ(a) - δ(w)); for 3°< T < 28°. Copyright (C) 2000 Elsevier Science Ltd.
UnivIS-Import:2015-03-09:Pub.2000.nat.dgeo.IGM.LG.oxygen_20

Oxygen isotopes in the Azores islands: Crustal assimilation recorded in olivine - Genske, Felix; Beier, Christoph; Haase, Karsten; Turner, Simon P.; Krumm, Stefan; Brandl, Philipp (Geology, 2013)
Oxygen isotope ratios of olivine have become a widely used tool for the study of magmatic systems, especially in the interpretation of source heterogeneities in mantle plume-derived ocean island basalts. The underlying assumption is that fresh minerals provide a better guide to magma δO than bulk rock analyses and that olivine is also likely to be a major phenocryst phase in primitive magmas. However, distinctions between source compositions and the effects of subsequent magma evolution have not always been thoroughly scrutinized. For the Azores samples investigated here, we can demonstrate that the δO variation (+4.84‰ to +5.25‰ Vienna standard mean ocean water) observed in the olivine phenocryst population is closely linked to evolution in the host magmas during ascent to the surface. We observe a linear, positive correlation between forsterite (Fo) content and δO in all of the individual island lava suites. This forces us to conclude that the low oxygen isotope ratios result from combined assimilation and fractional crystallization processes, the assimilant being hydrothermally (temperature > 250 C) altered, lower oceanic crust. Linear regression of the measured δO olivine values to Fo suggests a homogeneous mantle source with δO = +5.2‰ ± 0.1‰. © 2013 Geological Society of America.

Oxygen isotopes of bovid teeth: archives of palaeoclimatic variations in archaeological deposits of Ganga Plain. - Joachimski, Michael; et al. (Quaternary Research, 2004)
UnivIS-Import:2018-09-05:Pub.2004.nat.dgeo.IGM.LG.oxygen

Oxygen isotopes of bovid teeth as archives of paleoclimatic variations in archaeological deposits of the Ganga plain, India - Joachimski, Michael; et al. (Quaternary Research, 2004)
UnivIS-Import:2015-03-09:Pub.2004.nat.dgeo.IGM.LAG.oxygen

Oxygen Isotope Stratigraphy - Grossman, Ethan; Joachimski, Michael (Geological Timescale 2020, 2020)

Oxygen mobility in the perovskite SrTi1-xFexO3-ð (x = 0.8) - Mashkina, Elena; Magerl, Andreas; Ollivier, Jacques; Göbbels, Matthias; Seifert, Friedrich (Physical Review B - Condensed Matter and Materials Physics, 2006)
The dynamics of long range translation and local motions of oxygen in SrTi0.2 Fe0.8 O3-δ have been studied by electrical conductivity and quasielastic neutron scattering. The activation energy of the translational ionic diffusion measured by electrical conductivity is 0.97 eV for T>900°C. Both quasielastic linewidths and quasielastic intensities in neutron scattering show the presence of two motions. The Q independences indicate a localized character for these oxygen diffusion modes with activation energies of 0.43 and 0.27 eV for the "fast" and the "slow" local jumps, respectively. A model for the local oxygen motion is proposed involving oxygen jumps in the (0 k 0) plane either directly to the next unit cell or performing detours combining two and two site jumps resulting in the same final momentum transfer. © 2006 The American Physical Society.
UnivIS-Import:2015-03-09:Pub.2006.nat.dgeo.IGM.LM.oxygen

Oyster-dominated macrobenthic associations in the Cenomanian of Djebel Bouarif (Aures Mountains, Northeastern Algeria) - Aouissi, Riadh; Abdelhady, Ahmed Awad; Martinez, Sergio; Ahmed, Mohamed S.; Hannaa, Wagih; Jain, Sreepat; Salmi-Laouar, Sihem (Cretaceous Research, 2023)
In the Batna area of Algeria, the Cenomanian is represented by the Smail Marls Formation, a highly fossiliferous unit with a diverse benthic macrofauna (mainly of ostreid bivalves). A total of 1090 specimens belonging to 65 macrobenthic species were identified from 19 stratigraphic samples. The macrofaunal communities were quantitively analyzed using the hierarchical clustering (HC), nonmetric multidimensional scaling (NMDS), and permutational analysis of variance (PERMANOVA). Five distinct associations are recognized: 1) Costagyra olisiponensis, 2) Rhynchostreon suborbiculatum, 3) Aspidiscus cristatus, 4) Rhynchostreon suborbiculatum-Mecaster ameliae, and 5) Pycnodonte vesicularis. Data suggests that during the Cenomanian, the dominance of high-energy opportunistic oyster species within the soft marly sediments are related to their adaptive strategies. The changes noted in the community structure are attributed to sea-level fluctuations, rate of sedimentation and the prevailing hydrodynamics. Towards the uppermost Cenomanian and the Cenomanian–Turonian boundary, the oysters become rare due to eustatic sea-level rise and this decline coincides with increasing predation intensity on oysters and the destruction of their shallower habitats.
CRIS-Team Scopus Importer:2023-06-30
Keywords: Benthic associations; Bivalves; North Africa; Paleoenvironmental reconstruction; Upper Cretaceous

Palaeobotryllus and friends: Cambro-Ordovician record of probable ascidian tunicates - Lehnert, Oliver; Miller, James F.; Cochrane, Karen (Acta Universitatis Carolinae - Geologica, 1999)

Palaeoclimate reconstructions of the Middle Jurassic of Kachchh (western India): An integrated approach based on palaeoecological, oxygen isotopic, and clay mineralogical data - Fürsich, Franz; Singh, Indabir; Joachimski, Michael; Krumm, Stefan; Schlirf, M; Schlirf, S. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2005)
The Middle Jurassic sedimentary succession of the Kachchh Basin shows significant changes in lithology, faunal content and diversity across the Bathonian-Callovian boundary. The change in lithology from predominantly carbonates in the Middle and Late Bathonian to siliciclastics in the Callovian is accompanied by a drop in species diversity from high to moderate. Characteristic faunal elements of the Bathonian (corals, sponges, the bivalves Eligmus and members of the Opinae) are absent or rare in the Callovian. In contrast, Callovian sediments contain comparatively high proportions of nuculid bivalves. The clay mineral assemblage reveals prominent variations in the smectite vs. kaolinite abundance, especially during the Bathonian to Callovian transition. From the Bajocian to the Middle Bathonian, smectite becomes the dominant clay mineral and is nearly exclusively present in the Late Bathonian. Towards the Middle Callovian, its content gradually decreases and kaolinite becomes the dominant clay mineral. Illite generally is only a minor component throughout the Middle Jurassic. Based on these results, the Bajocian to Middle Bathonian time interval is interpreted to represent subtropical climatic conditions with seasonal droughts and a moderate supply of terrigenous clastics to the basin. The Late Bathonian was a period with a semi-arid climate, hot seasonal droughts and a minor input of terrigenous clastics. The increase in kaolinite contents in the Callovian suggests a subtropical humid climate with less prominent seasonal droughts and a higher input of siliclastics into the basin accompanied by a higher nutrient influx. Oxygen isotope ratios measured on Bathonian to early Callovian brachiopod shells give palaeotemperatures of 19-24°C. Callovian to Oxfordian paleotemperatures calculated from oxygen isotopes measured on belemnite rostra range from 11 to 21°C. The lower palaeotemperatures estimated from the oxygen isotopic composition of belemnite calcite are explained by assuming that the belemnites spent most of their life span in colder regions of the Malagassy Gulf and migrated into the warmer subtropical waters of the Kachchh Basin. Combining these various lines of evidence, the changes in lithology and faunal composition taking place in the Kachchh Basin during the Middle Jurassic appear to reflect largely a change towards increasing humidity rather than a distinct decrease in water temperature. © 2004 Elsevier B.V. All rights reserved.
Keywords: Clay mineralogy; India; Jurassic; Kachchh Basin; Oxygen isotopes; Palaeoclimate; Palaeoecology

Palaeoecology of Late Triassic conodonts: Constraints from oxygen isotopes in biogenic apatite. - Rigo, Manuel; Joachimski, Michael (Acta Palaeontologica Polonica, 2010)
The oxygen isotopic composition of conodont apatite derived from the Late Triassic (Carnian to lower Norian), Pignola 2 and Sasso di Castalda sections in the Lagonegro Basin (Southern Apennines, Italy) was studied in order to constrain the habitat of Late Triassic conodont animals. Oxygen isotope ratios of conodonts range from 18.5 to 20.8‰ V-SMOW, which translate to palaeotemperatures ranging from 22 to 31°C, assuming a δ 18O of Triassic subtropical sea water of -0.12‰ V-SMOW. These warm temperatures, which are well comparable to those of modern subtropical-tropical oceans, along with the body features of the conodont animal suggest that conodont 1 δ8O values reflect surface water temperatures, that the studied conodont taxa lived in near-surface waters, and that δ 18O values of Late Triassic conodonts can be used for palaeoclimatic reconstructions.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LG.palaeo_4
Keywords: Conodonta; Late Triassic; Oxygen isotope; Palaeoecology; Palaeotemperatures; Tethys

Palaeoecology of tropical marine invertebrate assemblages from the Late Triassic of Misurina, Dolomites, Italy - Hausmann, Imelda M.; Nuetzel, Alexander; Roden, Vanessa; Reich, Mike (Acta Palaeontologica Polonica, 2021)
Two marine invertebrate fossil assemblages from the Late Triassic Cassian Formation (Dolomites, northern Italy) were examined to assess their diversity and palaeoecology. Surface and bulk samples from the localities Misurina Landslide and Lago Antorno were taken and analysed separately. Both benthic assemblages are relatively similar in taxonomic composition. Gastropods form the most abundant and diverse group, followed by bivalves. Disarticulated echinoderm ossicles are also common in the bulk sample from Misurina Landslide, but they are rare at Lago Antorno. The Misurina Landslide outcrop has yielded two echinoderm Palaeozoic holdovers, the ophiocistioid Linguaserra triassica and plates of putative proterocidarids, supporting the earlier hypothesis that such basins acted as refugia. The gastropod species Coelostylina conica, Prostylifer paludinaris, and Ampezzopleura hybridopsis are characteristic elements of both assemblages. The gastropod Jurilda elongata, however, is the most abundant species at Misurina Landslide, whereas juveniles of the gastropod species Dentineritaria neritina dominate the assemblage from Lago Antorno. Newly described gastropod taxa are Angulatella bizzarinii Nützel and Hausmann gen. et sp. nov., Bandellina compacta Nützel and Hausmann sp. nov., and Ampezzogyra angulata Nützel and Hausmann sp. nov. Fifty-seven invertebrate species were found in the bulk sample from Misurina Landslide and 26 species were recovered from the bulk sample from Lago Antorno. However, sample size from Lago Antorno was much smaller than that from Misurina. Diversity indices (Shannon, Simpson, Berger-Parker) show similar moderate diversities in both assemblages. Rarefaction curves and rank-abundance distributions also point to very similar diversities and ecological structures of the fossil assemblages. Both assemblages are autochthonous or parautochthonous, stemming from basinal, soft-bottom habitats. Their taxonomic composition differs significantly from that of other faunas known from the Cassian Formation. The tropical marine Cassian palaeoecosystem was highly complex and its diversity is still far from being fully explored.
CRIS-Team Scopus Importer:2021-03-05
Keywords: Alps; Carnian; Cassian Formation; Diversity; Echinodermata; Ladinian; Mollusca; Small body size

Palaeoenvironments of the late Triassic Rhaetian Sea: Implications from oxygen and strontium isotopes of hybodont shark teeth - Fischer, Jan; Voigt, Silke; Franz, Matthias; Schneider, Joerg W.; Joachimski, Michael; Tichomirowa, Marion; Goetze, Jens; Furrer, Heinz (Palaeogeography, Palaeoclimatology, Palaeoecology, 2012)
The oxygen and strontium isotopic composition of 125 teeth of the hybodont sharks Lissodus and Hybodus from various late Triassic (Rhaetian) bone bed localities in the Central European Basin are used as environmental and ecological tracers for the shallow epicontinental Rhaetian Sea. The preservation of tooth enameloid was ascertained by cathodoluminescence microscopy. Mean δ 18O P values differ regionally across the Rhaetian Sea with values of 18.6±0.6‰ near the western gate, 16.1±0.8‰ in the east, 15.4±0.6‰ in the southeast, and 17.7±0.9‰ in the south. The δ 18O P values in the eastern Rhaetian Sea are 4-5‰ lower relative to Tethyan seawater, while teeth from the southern and western parts close to the marine gates are less fractionated. The strontium isotopic composition of teeth from most localities is more radiogenic in comparison to late Triassic seawater. The observed spatial δ 18O P trend in the Rhaetian Sea indicates a shift from marine to brackish conditions in the south and west towards extensively brackish conditions with salinities of less than 16‰ in the east, thus confirming the existence of two marine gates. Brackish conditions persisted throughout early Rhaetian times, and were maintained by increased fluvial discharge from the Vindelician-Bohemian and Fennoscandian Highs as a result of enhanced atmospheric moisture availability in the course of the Rhaetian transgression. The δ 18O P values of Lissodus and Hybodus indicate euryhaline behaviour of Rhaetian hybodonts by exceeding modern shark intraspecific variability. The lack of accordance in δ 18O P values between different isotopically conspicuous localities in the Rhaetian Sea contradicts a basin-wide migration pattern. Differences between co-site taxa might indicate some degree of niche partitioning. © 2012 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.palaeo
Keywords: Hybodont sharks; Oxygen isotopes; Palaeoecology; Rhaetian; Salinity; Strontium isotopes

Palaeokarst evidence for widespread regression and subaerial exposure in the middle Katian (Upper Ordovician) of Baltoscandia: significance for global climate. - Calner, Mikael; Lehnert, Oliver; Nolvak, Jaak (Palaeogeography, Palaeoclimatology, Palaeoecology, 2010)
We report on widespread and contemporary palaeokarst in the middle Katian (Upper Ordovician) of Sweden, Estonia and Latvia, the first major palaeokarst horizon to be reported from the Ordovician of Baltoscandia. The solution features occur within a few metres of thick zone of limestone immediately below the widespread Fjäcka Shale and are related to an unconformity with preserved palaeorelief in the Slandrom Limestone in Sweden and the time-equivalent Saunja Formation in Estonia and Latvia. Facies evidence for a karst origin comes from several outcrops and core sections and includes 1) frequent karren-like morphologies interpreted as 'Swiss-cheese' karst [. sensu Baceta et al., 2001], 2) local occurrences of solution/collapse breccia, 3) presence of bladed pseudospar crystals in solution cavities, and 4) carbon isotope values indicating meteoric influence to the succession. These findings are herein put in context with previously reported, large-scale erosional channels that may cut down several tens of metres below the Fjäcka Shale in the subsurface Baltic Sea area, and with regional, anomalous thickness variations in the Slandrom Limestone and Saunja Formation, all together forming strong support for regional exposure of the Baltoscandian continent in the middle Katian. High-resolution stable isotopic data show that the regression and lowstand of sea-level overlap with the Waynesville carbon isotope excursion. It resulted in basin-wide cessation of carbonate production near the Amorphognathus superbus and A. ordovicicus conodont zonal boundary. The contemporary development of palaeokarst in different confacies belts of the basin suggests that this was an extraordinary sea-level lowstand, herein interpreted as reflecting a middle Katian glaciation. © 2009 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LG.palaeo
Keywords: Baltoscandia; Fjäcka Shale; Katian; Ordovician; Palaeokarst; Saunja Formation; Slandrom Limestone

Palaeontological and facial features of the Upper Jurassic Hochstegen Marble (Tauern Window, Eastern Alps) - Kießling, Wolfgang (Terra Nova, 1992)

Palaeoproterozoic to Palaeozoic magmatic and metamorphic events in the Shackleton Range, East Antarctica: Constraints from zircon and monazite dating, and implications for the amalgamation of Gondwana - Schmädicke, Esther; et al. (Precambrian Research, 2009)
Keywords: Gondwana assembly; East Antarctica; Zircon and monazite U-Pb and Th-U-Pb dating; Shackleton Range

Palaeosalinity and palaeoclimatic geochemical proxies (elements Ti, Mg, Al) vary with Milankovitch cyclicity (1.3 to 2.0 Ma), OGCP cores, Palaeolake Olduvai, Tanzania - Stanistreet, Ian G.; Boyle, John F.; Stollhofen, Harald; Deocampo, Daniel M.; Deino, Alan; McHenry, Lindsay J.; Toth, Nicholas; Schick, Kathy; Njau, Jackson K. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2020)
The analysis of geochemical palaeoclimate and palaeosalinity proxy elements Ti, Mg, and Al, derived from X-ray fluorescence (XRF) scans of Olduvai Beds I and II from Olduvai Gorge Coring Project (OGCP) borehole Cores 2A and 3A, provides a record of cyclic variation between 1.3 Ma and 2.0 Ma. The boreholes were drilled into the depocentre of the Olduvai Basin between Fifth and FLK Faults, where Palaeolake Olduvai was most persistent and deepest. During most of Bed I the lake was particularly deep and probably meromictic, preserving high TOC contents and commonly preserving fine lamination due to lack of bioturbation. Accretion rates were also high during Bed I, when rates of basinal subsidence were maximal due to crustal stretching, associated with basaltic volcanism, towards the end of bimodal Ngorongoro volcanism. Basaltic magma effusive activity is manifested as tuffs, scoriaceous layers and the Bed I Basalt complex lava flows. A magnesium anomaly is recorded in the claystone geochemistry at this time and deposition of dolomite and limestone beds are restricted to this syn-volcanic phase of basin history. During Bed I deposition, accretion rates (0.23 mm/yr) were high enough to permit recognition of cycles with an average periodicity of 22.3 kyr corresponding to the Earth's precession. Only the high values during the Mg anomaly are adequate for the application of the palaeosalinity proxy element ratio Mg/Al. But Ti counts provide a cyclic record in both Bed I and Bed II. During Bed II deposition, the accretion rate was much slower (0.058 mm/yr) and cyclicity averaged 40.4 kyr, corresponding to Earth's orbital obliquity. The Bed II interval corresponds to MIS Stages 40 to 64. Coincidence of precessional and obliquity minima at 1.8 Ma explains the superdrought that affected the basin at the time of emplacement of Tuff IF, when the lake was dried out. The aridity of the sequence containing Tuff IA is also associated with a precessional minimum. The cyclic record suggests that three Bed I Basalt flows were extruded at 1.94 Ma during a time span lasting between 6 kyr and 15 kyr.
CRIS-Team Scopus Importer:2020-03-31
Keywords: Basaltic magmatism; Obliquity; Olduvai Basin; Orbital forcing; Precession; XRF scanning

Palaeovegetation changes recorded in Palaeolake Olduvai OGCP Core 2A (2.09–2.12 Ma) Naibor Soit Formation Olduvai Gorge, Tanzania - Rodríguez-Cintas, A.; Albert, R. M.; Bamford, M. K.; Stanistreet, I. G.; Stollhofen, Harald; Stone, J. R.; Rivera-Rondón, C.; Pronzato, R.; Njau, J. K.; Schick, K.; Toth, N. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2020)
For five decades Olduvai Gorge has been a key site to reconstruct and understand the relationship between environmental and landscape conditions and use of affordances by early African hominin populations. Following the first Olduvai Gorge Coring project (OGCP) during 2014, a multiproxy microbiological analysis, which includes phytoliths, pollen, diatoms, sponge spicules and chrysophyte cysts, was undertaken on samples collected from various borehole cores. The aim of the study is to better understand palaeoenvironmental and palaeovegetation conditions and changes through time and their relationship to hominin presence and evolution. This study details the first palaeobotanical and palaeoenvironmental study of Borehole 2A at Olduvai Gorge. It represents the as yet oldest known sedimentary sequence in the Olduvai Basin for a portion of the pre-Bed I Naibor Soit Formation; this is a unit that is not accessible in any natural exposures in Olduvai Gorge, and has only recently been encountered by drilling. Here we present the results from a particularly phytolith-prone portion between 2.09 Ma and 2.12 Ma. Phytolith results indicate a savannah environment dominated by grasses, where Poaceae were a key component and where the C3 Pooideae grasses were mostly dominant, alternating with C4 grasses. Oscillations between grass subfamilies, C3 Pooideae, C4 Chloridoideae, and C4 Panicoideae to lesser degrees, indicate five substantial climatic shifts, varying between more humid and arid conditions. Associated with phytoliths, freshwater indicators such as diatoms, sponge spicules and chrysophyte cysts were also identified, suggesting the presence of wetlands in the lake catchment area. Pollen is extremely rare in the sediments but when present, comprises fungal spores and Poaceae pollen, thus supporting the wetland and grassland reconstructions, respectively. These results offer for the first time, a whole picture of the palaeovegetation and associated palaeoenvironments for this pre-Bed I period. Together with previous results from other areas and chronological periods, they improve our understanding of the evolution and adaptation of early hominins and their close relationship to the surrounding landscape.
CRIS-Team Scopus Importer:2020-08-28
Keywords: East Africa; Diatoms; Sponge spicules; Pleistocene; Phytoliths; Palaeoenvironmental reconstruction