Facies characterization of Mid-Mesozoic deep-water sediments by quantitative analysis of siliceous microfaunas - Kießling, Wolfgang (Facies, 1996)
Keywords: Antarctic Peninsula; Deep water; Early cretacious; Jurassic; Oman Mountains; Radiolaria; Southern Alps; Sponge spicules

Facies-controlled diagenesis in an upper jurassic coral patch-reef (Lower Tithonian, Southern Germany) - Joachimski, Michael; Scheller, Josef (Facies, 1987)
The coral patch-reef of Laisacker (Neuburg a.d. Donau, Southern Franconian Alb) exhibits three facies zones: the reef core consists of reef debris, there is almost no reef framework. The core facies, interfingering with the reef debris facies is built up by fine-grained reef detritus with intercalated coarse-grained layers of partly high porosity (up to 24%). They mainly consist of coral fragments (up to 83%) and reach 0.80 m in thickness. These coarse-grained layers have been formed by storms. The interreef facies corresponds to massive limestones. Destruction of the reef framework was favoured by bioerosion. The high still open porosity of the coarsegrained reef rubble was caused by high freshwater flow rates delimiting cementation and favouring dissolution. © 1987 Institut für Paläontologie, Universität Erlangen.

Facies development across the Late Silurian Lau Event based on temperate carbonates of the Prague Basin (Czech Republic) - Gocke, Martina; Lehnert, Oliver; Fryda, Jiri (Facies, 2012)
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.facies

Facies development and sequence stratigraphy of the Ludfordian (Upper Silurian) deposits in the Zbruch River Valley, Podolia, western Ukraine: Local facies overprint on the δ13Ccarb record of a global stable carbon isotope excursion - Jarochowska, Emilia; Kozłowski, Wojciech (Facies, 2014)
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LP.facies
Keywords: Baltica; Lacustrine environments; Lau Event; Microbial dolomite precipitation; Stable carbon isotopes

Facies, diagenesis and carbon isotopes of the Early Permian Gipshuken Formation (SValbard). - Buggisch, Werner; Blomeier, Dierk; Joachimski, Michael (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 2012)
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.facies_9

Facies discrimination in a mixed fluvio-eolian setting using elemental whole-rock geochemistry - Applications for reservoir characterization. - Svendsen, Johan; Friis, Henrik; Stollhofen, Harald; Hartley, Neil (Journal of Sedimentary Research, 2007)
Fluvio-eolian successions are generally characterized by a high degree of complexity and internal heterogeneity. Quantifying the rapid facies changes in time and space is a major challenge to characterization of hydrocarbon reservoirs. We present a method for facies discrimination in fluvio-eolian successions. The method presented here is developed on the modern fluvio-eolian sediments from the Skeleton Coast dune field, Namibia. The examined sediments comprise eight different facies types: eolian dune sands, interdune fluvial channel sands, intraerg mass-flow deposits, intraerg hyperconcentrated-flow deposits, fluvial channel sands, fluvial mud, lacustrine heterolithic sand, and lacustrine heterolithic mud. The contrasting provenance of the fluvial and eolian sediments results in a distinct source fingerprint which can be discriminated using elemental whole-rock geochemistry. A multivariate statistical technique performed on the geochemical data has enabled discrimination of seven of the eight facies types. Furthermore, the facies discrimination method allowed a quantitative estimate of the degree of fluvial reworking of eolian sand. The Skeleton Coast dune field was chosen as a test area for geochemical facies discrimination, because of its remarkable difference between the immature fluvial source and the mature quartz-rich eolian source. We hope that the method presented here can be applied to subsurface data from geological settings with the same difference in fluvial and eolian sources. It is furthermore hoped that the method can be used in more complex sedimentological settings. Copyright © 2007, SEPM (Society for Sedimentary Geology).
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LG.facies

Facies from Palaeozoic Reefs and Bioaccumulations - Vennin, Emmanuelle; Aretz, Markus; Boulvain, Frédéric; Munnecke, Axel (2007)
Keywords: Facies; Palaeozoic; Reefs; Bioaccumulations

Facies of two important Early Triassic gastropod lagerstätten: implications for diversity patterns in the aftermath of the end-Permian mass extinction - Nützel, Alexander; Schulbert, Christian (Facies, 2005)
Two important lagerstätten of Early Triassic gastropods, the Sinbad Limestone (Utah, USA) and the Gastropod Oolite (North Italy) yield about 40% of all described Early Triassic species. This great contribution to the global diversity and the exceptional good preservation render high information content, which characterizes fossil lagerstätten. The Smithian Sinbad Limestone contains the most diverse Early Triassic gastropod fauna. At the type locality, it occurs in single, probably storm-induced shell bed within a series of high energy deposits underlain by intertidal microbial mats and subtidal oolite/peloid shoals. The main shell bed contains about 40 invertebrate taxa. Gastropods, scaphopods, and bivalves are most abundant and form an assemblage, which is dominated by small neritaemorphs, the opisthobranch Cylindrobullina convexa and the scaphopod Plagioglypta (annulated tubes). This assemblage lived on shallow, subtidal soft-bottoms based on sedimentological and ecological characteristics. The Dienerian (to Smithian?) Gastropod Oolite Member (North Italy) has extremely abundant, probably salinity-controlled gastropod faunas with low species richness. Almost monospecific assemblages of Pseudomurchisonia kokeni as well as assemblages with about four species are present in the Gastropod Oolite. Modern hydrobiid mudsnail faunas which are adapted to strongly fluctuating salinity in intertidal to shallow subtidal coastal areas form probably a suitable model for the Gastropod Oolite biota. Gastropods from the Werfen- and Moenkopi-Formation lagerstätten are well preserved compared to other Early Triassic deposits. The high contribution to the global diversity of just two sites suggests very incomplete sampling and preservational bias. However, the low richness of the major faunas reflects depauperate Early Triassic faunas and slow recovery from the Permian/Triassic crisis. © Springer-Verlag 2005.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LP.facies
Keywords: Early Triassic; Gastropoda; Italy; Permian/Triassic mass extinction; Recovery; USA

Facilitation of coral reef growth by coralline red algae – patterns during the last 150 million years - Teichert, Sebastian; Steinbauer, Manuel; Kießling, Wolfgang (macro 2019 – Bridging local patterns and global challenges, 2019)
Aim: Modern crustose coralline red algae (CCA) play a key role in the construction of coral reefs. It is unclear, however, if their function as consolidators of coral reefs was similar pronounced in the geological past. Accordingly, we tested (1) when the presence of CCA was crucial for the formation of coral reefs throughout the last 150 Ma. We further investigated if (2) the capacity of CCA to reinforce coral reefs suffered two transient crises as a result of the diversification of major herbivore groups. Location: The study involves reef structures from tropical and subtropical environments on a global scale, ranging from the Cretaceous (145.5 Ma) to the Pleistocene (0.01 Ma). Methods: For 736 reef sites, we tested if the fractions of coral reefs are positively correlated with the fractions of those reefs with CCA as secondary reef builders. Implementing generalized linear models (GLM), we tested if fluctuations in the functioning of CCA as secondary reef builders can be explained by the diversification of herbivores or other potential explanatory variables – sea level, δ18O, CO2 and CCA species diversity. Results: The presence of CCA was found to positively correlate with the abundance of coral reefs throughout the analysed period. Model results show that the probability that reefs contain CCA as major reef builders increases with CCA diversity and δ18O while the presence of newly evolved herbivores has a negative effect. High correlations between explanatory variables limit the interpretation of model results. Main conclusions: The presence of CCA is crucial for the formation of coral reefs. This facilitation suffered two crises probably linked to diversification of major herbivore groups. As CCA have evolved adaptations to grazing pressure they now facilitate the formation of modern coral reefs.<br

Factors Influencing the Thermal Efficiency of Horizontal Ground Heat Exchangers - Di Sipio, Eloisa; Bertermann, David (Energies, 2017)
The performance of very shallow geothermal systems (VSGs), interesting the first 2 m of depth from ground level, is strongly correlated to the kind of sediment locally available. These systems are attractive due to their low installation costs, less legal constraints, easy maintenance and possibility for technical improvements. The Improving Thermal Efficiency of horizontal ground heat exchangers Project (ITER) aims to understand how to enhance the heat transfer of the sediments surrounding the pipes and to depict the VSGs behavior in extreme thermal situations. In this regard, five helices were installed horizontally surrounded by five different backfilling materials under the same climatic conditions and tested under different operation modes. The field test monitoring concerned: (a) monthly measurement of thermal conductivity and moisture content on surface; (b) continuous recording of air and ground temperature (inside and outside each helix); (c) continuous climatological and ground volumetric water content (VWC) data acquisition. The interactions between soils, VSGs, environment and climate are presented here, focusing on the differences and similarities between the behavior of the helix and surrounding material, especially when the heat pump is running in heating mode for a very long time, forcing the ground temperature to drop below 0 °C.
Keywords: very shallow geothermal energy; horizontal collectors; thermal conductivity; volumetric water content; soil

Fanthalamia kadiri nov. sp., a new "Sphinctozoan" sponge from the Triassic (Carnian) of Turkey - Senowbari-Daryan, Baba; Link, Michael; Garcia-Bellido, Diego C. (Studia Universitatis Babes-Bolyai : Geologia, 2003)
A new sphinctozoid sponge - Fanthalamia kadiri - is described from the Upper Triassic (Carnian) of Antalya area, southern Turkey. This is the second species of the genus Fanthalamia found in Upper Triassic of Turkey.
UnivIS-Import:2015-04-14:Pub.2003.nat.dgeo.IGM.LP.fantha
Keywords: sponge; Sphinctozoa; Triassic; Carnian; Turkey

Fast-growing species shape the evolution of reef corals - Siqueira, Alexandre C.; Kießling, Wolfgang; Bellwood, David R. (Nature Communications, 2022)
Ecological interactions are ubiquitous on tropical coral reefs, where sessile organisms coexist in limited space. Within these high-diversity systems, reef-building scleractinian corals form an intricate interaction network. The role of biotic interactions among reef corals is well established on ecological timescales. However, its potential effect on macroevolutionary patterns remains unclear. By analysing the rich fossil record of Scleractinia, we show that reef coral biodiversity experienced marked evolutionary rate shifts in the last 3 million years, possibly driven by biotic interactions. Our models suggest that there was an overwhelming effect of staghorn corals (family Acroporidae) on the fossil diversity trajectories of other coral groups. Staghorn corals showed an unparalleled spike in diversification during the Pleistocene. But surprisingly, their expansion was linked with increases in both extinction and speciation rates in other coral families, driving a nine-fold increase in lineage turnover. These results reveal a double-edged effect of diversity dependency on reef evolution. Given their fast growth, staghorn corals may have increased extinction rates via competitive interactions, while promoting speciation through their role as ecosystem engineers. This suggests that recent widespread human-mediated reductions in staghorn coral cover, may be disrupting the key macroevolutionary processes that established modern coral reef ecosystems.
CRIS-Team Scopus Importer:2022-05-20

Fate of nitrate during groundwater recharge in a fractured karst aquifer in Southwest Germany - Visser, Anna-Neva; Lehmann, Moritz F.; Rügner, Hermann; Mazo D'Affonseca, Fernando; Grathwohl, Peter; Blackwell, Nia; Kappler, Andreas; Osenbrück, Karsten (Hydrogeology Journal, 2021)
Over the past decades, fractured and karst groundwater systems have been studied intensively due to their high vulnerability to nitrate (NO3−) contamination, yet nitrogen (N) turnover processes within the recharge area are still poorly understood. This study investigated the role of the karstified recharge area in NO3− transfer and turnover by combining isotopic analysis of NO3− and nitrite (NO2−) with time series data of hydraulic heads and specific electrical conductivity from groundwater monitoring wells and a karstic spring in Germany. A large spatial variability of groundwater NO3− concentrations (0.1–0.8 mM) was observed, which cannot be explained solely by agricultural land use. Natural-abundance N and O isotope measurements of NO3− (δ15N and δ18O) confirm that NO3− derives mainly from manure or fertilizer applications. Fractional N elimination by denitrification is indicated by relatively high δ15N- and δ18O-NO3− values, elevated NO2− concentrations (0.05–0.14 mM), and δ15N-NO2− values that were systematically lower than the corresponding values of δ15N-NO3−. Hydraulic and chemical response patterns of groundwater wells suggest that rain events result in the displacement of water from transient storage compartments such as the epikarst or the fissure network of the phreatic zone. Although O2 levels of the investigated groundwaters were close to saturation, local denitrification might be promoted in microoxic or anoxic niches formed in the ferrous iron-bearing carbonate rock formations. The results revealed that (temporarily) saturated fissure networks in the phreatic zone and the epikarst may play an important role in N turnover during the recharge of fractured aquifer

Fatigue strength of bilayer yttria-stabilized zirconia after low-temperature degradation - Pereira, Raíssa Monteiro; Belli, Renan; Lohbauer, Ulrich; Hurle, Katrin; Campos, Tiago Moreira Bastos; Thim, Gilmar Patrocínio (Journal of the Mechanical Behavior of Biomedical Materials, 2024)
This study examined the impact of interfacial interactions on bilayer yttria-stabilized zirconia (YSZ) used in dental restorations. In-house bilayer structures of 3YSZ and 5YSZ composition underwent hydrothermal degradation to compare the properties of control and low-temperature degradation (LTD) treated groups. Biaxial flexural strength via piston-on-three-balls, staircase fatigue strength over 106 cycles at 15 Hz, phase characterization and quantification through XRD and Rietveld refinement, and fractography were conducted. Weibull analysis was employed to determine the Weibull modulus and characteristic strength. Results demonstrated an enhancement in the mechanical performance of 3YSZ composition after LTD treatment, whereas the mechanical properties of 5YSZ remained largely unaffected post-degradation. Fractographic analysis revealed that failure originated at the surface tensile location across all specimen groups. These findings offer insights into the mechanical behavior of bilayer zirconia structures and reinforce the significance of hydrothermal treatment in enhancing their performance, particularly in the case of 3Y compositions.
CRIS-Team Scopus Importer:2024-09-20
Keywords: Biaxial flexural strength; Bilayer; Fatigue; Low-temperature degradation; Mechanical properties; Zirconia

Fault-controlled fluid circulation and diagenesis along basin-bounding fault systems in rifts – insights from the East Greenland rift system - Salomon, Eric; Rotevatn, Atle; Kristensen, Thomas Berg; Grundvåg, Sten-Andreas; Henstra, Gijs Allard; Meckler, Anna Nele; Albert, Richard; Gerdes, Axel (Solid Earth, 2020)
In marine rift basins, deep-water clastics (>200 m) in the hanging wall of rift- or basin-bounding fault systems are commonly juxtaposed against crystalline “basement” rocks in the footwall. A distinct feature of such fault systems is therefore the juxtaposition of relatively highly permeable, unconsolidated sediments against relatively low-permeable basement rocks. Due to limited surface exposure of such fault zones, studies elucidating their structure and evolution are rare. Consequently, their impact on fluid circulation and diagenesis within and proximal to the fault zone as well as into the hanging wall strata are also poorly understood. Motivated by this, we here investigate a well-exposed strand of a major basin-bounding fault system in the East Greenland rift system, namely the Dombjerg Fault which bounds the Wollaston Forland Basin, northeast (NE) Greenland. Here, syn-rift deep-water clastics of Late Jurassic to Early Cretaceous age are juxtaposed against Caledonian metamorphic basement. Previously, a ∼ 1 km wide zone of pervasive pore-filling calcite cementation of the hanging wall sediments along the Dombjerg Fault core was identified (Kristensen et al., 2016). In this study, based on U–Pb calcite dating, we show that cementation and formation of this cementation zone started during the rift climax in Berrisian–Valanginian times. Using clumped isotope analysis, we determined cement formation temperatures of ∼ 30–70 ∘C. The spread in the formation temperatures at similar formation age indicates variable heat flow of upward fluid circulation along the fault in the hanging wall sediments, which may root in permeability variations in the sediments. Calcite vein formation, postdating and affecting the cementation zone, clusters between ∼ 125 and 100 Ma in the post-rift stage, indicating that fracturing in the hanging wall is not directly related to the main phase of activity of the adjacent Dombjerg Fault. Vein formation temperatures at ∼ 30–80 ∘C are in a similar range as cement formation temperatures. Further, similar minor element concentrations of veins and adjacent cements indicate diffusional mass transfer into fractures, which in turn infers a subdued fluid circulation and low permeability of the fracture network. These results imply that the cementation zone formed a near-impermeable barrier soon after sediment deposition, and that low effective permeabilities were maintained in the cementation zone even after fracture formation, due to poor fracture connectivity. We argue that the existence of such a cementation zone should be considered in any assessments that target basin-bounding fault systems for, e.g., hydrocarbon, groundwater, geothermal energy, and carbon storage exploration. Our study highlights that the understanding of fluid flow properties as well as fault-controlled diagenesis affecting the fault itself and/or adjacent basinal clastics is of great fundamental and economic importance.

Faunal and facies changes through the mid Homerian (late Wenlock, Silurian) positive carbon isotope excursion in Podolia, western Ukraine - Jarochowska, Emilia; Munnecke, Axel; Frisch, Konstantin; Ray, David C.; Castagner, Ariane (Lethaia, 2016)
The late Wenlock is characterized by two global regressive-transgressive eustatic cycles in association with a double-peaked positive carbon isotope excursion. The onset of the excursion coincides with an extinction event affecting graptolites (the lundgreni event) and proposed to affect conodonts (the Mulde Event) and proliferation of non-skeletal carbonates. In order to test the hypothesized relationships between eustatic and ecological changes, the tropical carbonate Homerian succession in Podolia has been examined with respect to conodont, sequence and δC stratigraphy. Four depositional sequences (DS) have been identified. The onset of the δC excursion occurs at the boundary between DS1 and DS2, corresponding to a forced regression of proposed glacioeustatic origin. The following rapid eustatic transgression associated with the highest δC values of 5.2‰ includes a higher-order shallowing episode recorded in Podolia as normal regression and a boundary between DS2 and DS3. This interval is distinguished by the presence of oncoids and thrombolitic buildups. The latest Wenlock eustatic fall and the corresponding second peak of the δC excursion corresponds in Podolia to a stratigraphic gap. The first δC peak (top of DS1 and DS2) corresponds to the O. bohemica longa conodont Zone, the interval between the two peaks (DS3) - to K. ortus absidata and C. murchisoni zones, and DS4 is tentatively placed in the lowermost Ludlow Series. The record of relative sea-level changes in Podolia is consistent with reconstructions based on successions in England and Sweden. The moderate drop in conodont taxonomic richness may reflect the primary depositional control over their proposed extinctio
Keywords: Baltica; Conodonts; Extinction; Lundgreni Event; Mulde Event; Sequence stratigraphy

Faunal evidence for reduced productivity and uncoordinated recovery in Southern Hemisphere Cretaceous/Paleogene boundary sections - Kießling, Wolfgang; et al. (Geology, 2007)
The mass extinction at the Cretaceous-Paleogene boundary is generally explained by a severe crisis in primary productivity, following a catastrophic bolide impact. Consistent with this scenario, Danian mollusk-dominated benthic shelf ecosystems of southern middle paleolatitudes (Neuquén Basin, Argentina) are characterized by (1) a stratigraphically limited low in macrofossil abundances; (2) an increase in starvation-resistant, nonplanktotrophic deposit feeders and chemosymbionts; (3) a reduction in the average body size of individuals; and (4) individuals with inactive lifestyles being more common than in the late Maastrichtian. Return to pre-extinction conditions of the various synecological attributes occurred over unequal time spans, indicating that recovery was uncoordinated with respect to ecological traits. Global comparison of ecological patterns suggests that reduced food supply (1) was a controlling factor in both hemispheres; (2) affected macrobenthic marine faunas at various distances from the Chiexulub impact site; and (3) was more effective in silicielastic environments as compared to oligotrophic carbonate settings. © 2007 Geological Society of America.
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LP.faunal
Keywords: Cretaceous-Paleogene boundary; Ecology; Mass extinction; Productivity; Southern Hemisphere

Faunenumschwung im frühen Jura Frankens - Nützel, Alexander; Schulbert, Christian (Geologische Blätter für Nordost-Bayern und angrenzende Gebiete, 2017)
In Franken ähneln sich Fazies und Ablagerungsbedingungen vor und nach dem Posidonienschiefer-Ereignis . Es handelt sich um aerobe bis dysaerobe Weichböden in nahezu gleicher paläogeographischer Position. Auch die Faunen weisen Gemeinsamkeiten auf, z. B. die generelle Kleinwüchsigkeit der benthischen Organismen sowie die Dominanz von Gastropoden und Muscheln. Ranghäufigkeiten der Gastropoden deuten auf eine ähnliche community-Struktur in Mistelgau und Buttenheim hin, bei der jeweils wenige Arten stark dominieren. Ophiurenossikel sind sowohl in Buttenheim als auch in Mistelgau sehr häufig. Trotz dieser Gemeinsamkeiten ist in den Faunen vor und nach dem Posidonienschiefer-Ereignis ein deutlicher taxonomischer Faunenumschwung (turnover) zu verzeichnen, der auf Artebene 100% beträgt und auf Gattungsgebene 60% überschreitet. Dies zeigt, dass die benthische Fauna des Amaltheentons dem Schwarzschieferereignis mit Anoxia nicht lateral auswich (Refugien) und nach dessen Ende das Südwestdeutsche Becken wiederbesiedelte. Vielmehr starben diese Faunen weitgehend aus und wurden nach dem Ende der anoxischen Periode durch Neueinwanderung ersetzt. Abweichend von diesem Muster, gibt es einige Arten, wie den holoplanktonischen Gastropoden Coelodiscus minutus oder die opportunistische Muschel Bositra buchi, die im Posidonienschiefer massenhaft auftreten und dann, z. B. in Mistelgau, weiterhin mindestens bis ins Aalenium vorkommen.<br
Keywords: Jura; Gastropoden; Bivalven; Pliensbachium; Massenaussterben

Feasibility Study of Future (Hypothetical) Scientific and Geothermal Wells in Franconia, Germany. - Drews, Michael; Bauer, Wolfgang; Stollhofen, Harald (Der Geothermie Kongress DGK 2017, 2017)

Feathery and network-like filamentous textures as indicators for the re-crystallization of quartz from a metastable silica precursor at the Rusey Fault Zone, Cornwall, UK - Yilmaz, Tim I.; Duschl, Florian; Di Genova, Danilo (Solid Earth, 2016)

FEG-SEM and STEM investigation of high temperature FeCrAl(RE) alloys - Bestmann, Michel; et al. (Journal of Corrosion Science and Engineering, 2003)
Keywords: FeCrAl(RE); Microstructure; Oxidation behaviour; Recrystallisation; Ultra-high purity

Ferruginous coated grains of microbial origin from the Lower Devonian (Pragian) of the Prague Basin (Czech Republic) – Petrological and geochemical perspective - Vodrážková, Stanislava; Kumpan, Tomáš; Vodrážka, Radek; Frýda, Jiří; Čopjaková, Renata; Koubová, Magdalena; Munnecke, Axel; Kalvoda, Jiří; Holá, Markéta (Sedimentary Geology, 2022)
A unique occurrence of ironstone lenses represented by ferruginous oncoids is reported from the offshore Řeporyje Limestone (Lower Devonian, Pragian) from the Prague Basin (the Stydlé Vody Quarry). The oncoidal cortices show distinct arrangement of hematite/chamosite and/or iron-bearing calcite laminae, which are irregular, wavy and with a relatively high degree of inheritance of shape of the topography of the underlying laminae. Micro-domes and bulges, comparable to those observed in stromatolites and laminae overgrowing topographic irregularities represented by agglutinated foraminifers cemented to oncoid surfaces, were fairly commonly observed. The foraminifers probably represent the earliest representatives of agglutinated foraminifera encrusting surfaces of ferruginous grains. The surfaces of oncoids are wavy and often wrinkled. Although no microbial remains that could have been directly associated with oncoidal growth were recorded, we regard above mentioned features as indicators of biogenicity of the precipitates. We could only speculate the nature of the microbial consortia, but we regard the alternation of Fe2+ (chamosite, iron-bearing calcite) and Fe3+ (hematite) phases as a result of coupled oxidation - reduction processes related to passive and/or active microbial metabolic activities (precipitation of ferrihydrite – hematite precursor) and passive mineral authigenesis mediated by microorganisms (precipitation of chamosite precursor). Spatially restricted occurrence of the oncoidal lenses along with Al/Al + Fe + Mn vs. Fe/Ti, Nd vs. Ce/Ce*, Eu/Sm vs. Sm/Yb and other crossplots suggest that hydrothermal fluids were the most probable source of ferrous iron. Since most of the known oolitic or oncolitic ironstones represent rather large sedimentary bodies deposited around storm wave base to shallow subtidal environments under influence of upwelled anoxic watermasses or continental runoff, the reported oncolitic mounds represent a specific example of ironstones formation.
CRIS-Team Scopus Importer:2022-07-22
Keywords: Ironstones; Microbialites; Oncoids; REE geochemistry; Trace elements geochemistry

Fibrous dolomite formation at a Miocene methane seep may reflect Neoproterozoic aragonite-dolomite sea conditions - Lu, Yang; Paulmann, Carsten; Mihailova, Boriana; Malcherek, Thomas; Birgel, Daniel; López Correa, Matthias; Lin, Zhiyong; Lu, Liuyi; Milker, Yvonne; Peckmann, Jörn (Communications Earth & Environment, 2023)
Fibrous dolomite widely formed in Neoproterozoic marine sedimentary environments, but apparently disappeared in the Phanerozoic. Here, fibrous dolomite is recognised in a Miocene methane seep limestone (Marmorito, Italy) by synchrotron X-ray diffraction, length slow crystal optics and primary zonation under cathodoluminescence, which is unexpected. Low δ13C values and their negative correlation with MgCO3 contents indicate a formation driven by highly alkaline pore waters and catalysis of dissolved sulphide generated by sulphate-driven anaerobic oxidation of methane. Cementing cavities of reefal carbonate, Neoproterozoic fibrous dolomite might have formed under sulphate-reducing conditions like Quaternary reef microbialites. Since the cavities of Neoproterozoic reefs were restricted microenvironments, the formation of fibrous dolomite was possibly favoured by catalysis similar to its Miocene seep counterpart. Our findings reinforce the concept of penecontemporaneous dolomite formation by sulphide catalysis and contribute to our understanding of the environmental conditions of the Neoproterozoic.
CRIS-Team Scopus Importer:2023-10-20

Field-based stable isotope analysis of carbon dioxide by mid-infrared laser spectroscopy for carbon capture and storage monitoring - van Geldern, Robert; Nowak, Martin; Zimmer, Martin; Szizybalski, Alexandra; Myrttinen, Anssi; Barth, Johannes; Jost, Hans-Juerg (Analytical Chemistry, 2014)

Field dependence of magnetic anisotropy in pyrrhotite: effects of texture and grain shape - de Wall, Helga; et al. (Physics of the Earth and Planetary Interiors, 1993)

Field mapping of magnetic susceptibility as tool for petrographic characterization of granitoids - A key study in the Hauzenberg pluton, Bavarian Forest, Germany - de Wall, Helga; Dietl, Carlo; Streit, Verena; Rueckert, David; Rohrmueller, Johann (Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, 2008)

Filograna (colonial serpulid worm tubes) from Upper Triassic (Norian) reef boulders of Taurus Mts. (southern Turkey) - Senowbari-Daryan, Baba; Link, Michael (Facies, 2005)
Two colonial serpulid worm tubes - Filograna taurica n. sp. and Filograna serialis n. sp. - from the Upper Triassic (Norian) reef boulders occurring in Taurus Mts. (south Turkey) are described. As bafflers, both species of Filograna build microbioherms reaching dimensions of up to 15 cm. Both species were not known either in Turkey or in any other Triassic localities of the Tethyan realm. © Springer-Verlag 2005.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LP.filogr
Keywords: Annelids; Filograna; Norian; Reef; Serpulids; Taurus; Triassic; Turkey

Filograna minor nov sp (Worm tube) from the middle triassic (Anisian) reef boulders of the Karaburun Peninsula, Western Turkey - Senowbari-Daryan, Baba; Link, Michael; Isintek, Ismail (Turkish Journal of Earth Sciences, 2007)
A colonial serpulid worm tube, Filograna minor nov. sp., from the Anisian reef boulders of the Karaburun Peninsula, Western Turkey is described. The Filograna-bearing boulders occur together with Anisian reef boulders within the Upper Anisian siliciclastic deposits of the Gerence Formation. Filograna minor differs from the Norian species Filograna serialis, described by Senowbari-Daryan and Link from the Taurus Mountains, by the smaller dimensions of the tubes. Copyright © TÜBİTAK.
UnivIS-Import:2015-04-14:Pub.2007.nat.dgeo.IGM.LP.filogr
Keywords: Anisian; Filograna; Karaburum Peninsula; Serpulid; Triassic; Turkey

Final Assembly of the Southwestern Central Asian Orogenic Belt as Constrained by the Evolution of the South Tianshan Orogen: Links With Gondwana and Pangea - Wang, Xin-Shui; Klemd, Reiner; Gao, Jun; Jiang, Tuo; Li, Jilei; Xue, Shengchao (Journal of Geophysical Research. Solid Earth, 2018)
The South Tianshan Orogen marks the final assembly of the southwestern Central Asian Orogenic Belt (CAOB) and the Karakum–Tarim cratons. Here we present an integrated mineralogical, geochemical, and geochronological study of the Wuwamen ophiolitic mélange in the South Tianshan to better understand the tectonic evolution of the western CAOB and its links to Gondwana and Pangea. Mantle peridotites with mineral compositions similar to those of abyssal peridotites and basalts with N‐MORB geochemical affinities suggest that the Wuwamen ophiolite was formed in a mid‐ocean ridge setting. Arc‐related gabbro and plagiogranite stocks intruding the mantle peridotites yielded zircon U–Pb ages of 441.1 ± 4.2 and 442.8 ± 2.4 Ma, indicating that the Wuwamen ophiolite got emplaced prior to 440 Ma. Sericite‐quartz schist from the ophiolitic mélange matrix with abundant 481–319 Ma detrital zircon grains is crosscut by a two‐mica granite dike with a zircon U–Pb age of 321.3 ± 1.7 Ma, thereby constraining the formation of the Wuwamen ophiolitic mélange at 320 Ma. In conjunction with published data, we propose that the South Tianshan Ocean opened in the late Neoproterozoic and promoted the subsequent separation of microcontinents in the western CAOB from the northeast Gondwana margin during Gondwana assembly. Furthermore, the closure of the South Tianshan Ocean led to the final assembly of the southwestern CAOB and the Karakum–Tarim cratons and their incorporation into Pangea at 320 Ma.<br
Keywords: Central Asian Orogenic Belt; Tianshan; Wuwamen ophiolite; Gondwana; Pangea

Fingerprinting facies of the Tuff IF marker, with implications for early hominin palaeoecology, Olduvai Gorge, Tanzania. - Stollhofen, Harald; Stanistreet, Ian G.; Mchenry, Lindsay J.; Mollel, Godwin F.; Blumenschine, Robert J.; Masao, Fidelis T. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2008)
The top of Tuff IF marks the upper boundary of the Plio-/Pleistocene Bed I succession exposed in Olduvai Gorge, NE Tanzania, a tephrostratigraphic interval that is well known for remarkable Oldowan archaeological and vertebrate fossil assemblages, including early hominins. Geochemically, Tuff IF is characterized by a relatively consistent silica-undersaturated trachytic to phonolitic composition that relates both in terms of numerical ages (1.79 Ma) and compositional constraints to Olmoti volcano, located 22-38 km E of Olduvai Gorge. Measured Tuff IF sections are characterized by a thick unwelded pyroclastic flow in proximal settings and a succession of surges and ashfalls that interfingers with fluvio-lacustrine deposits of the Olduvai Basin in the medial to distal settings. Only in those areas with a relatively low topographic gradient, in distal reaches and beyond the toe of an Olmoti-sourced volcaniclastic fan, did the Tuff IF marker develop a typical threefold subdivision comprising: (1) primary surges and minor fallout, (2) reworked pumice units as lateral correlatives of proximally emplaced pyroclastic flows and (3) a succession of mass flows in conjunction with aeolian and fluvially reworked units. The pyroclastic marker unit is thus highly heterogeneous with regard to its vertical and lateral facies architecture and this has immediate effects on its preservation potential and in situ burial of fossils and stone artifacts. Even though the volcanically-related environmental perturbations were probably more severe at the eastern lake margin, the evidence for at least temporary freshwater sources and trees suggests environments conducive to hominin activities, but not during emplacement of Tuff IF pyroclastic flows and surges. This inference is supported by the presence of rich Oldowan stone artifact assemblages immediately preceding and following the deposition of Tuff IF, but only extremely sparse archaeological traces from one site in Tuff IF, restricted to the upper, fluvially reworked portion of Tuff IF. Tuff IF facies record the maximum of a regressive (drying) cycle that correlates with regional marine arid indicators. An ecological crisis covering ∼ 2000-3500 a of time during Tuff IF deposition resulted not only from the lethal effects of explosive volcanism but also from its coincidence with a pronounced period of climate induced drought. These combined effects appear to have made at least the eastern basin uninhabitable by hominins and other vertebrates for most of the time during which Tuff IF accumulated. © 2007 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2008.nat.dgeo.IGM.LG.finger
Keywords: Oldowan hominins; Olduvai Gorge; Palaeoecology; Pleistocene; Pliocene; Tanzania; Tephrostratigraphy; Volcaniclastic sediments

Fingerprinting fluid evolution by trace elements in epithermal pyrite, Vatukoula Au-Te deposit, Fiji - Börner, Frederik; Keith, Manuel; Smith, Daniel J.; Barry, Tiffany L.; Neumann, Thomas; Klemd, Reiner (Ore Geology Reviews, 2021)
Tellurium (Te) is an important element for green technologies, including thin film photovoltaic panels. Stagnating supply caused by its by-product dependency together with an increasing demand will likely lead to a shortage in the near future. Pyrite may represent a potential target for the direct recovery of Te, since the concentrations of Te can reach weight percent levels under specific, but poorly constrained hydrothermal conditions. The Vatukoula (formerly Emperor) epithermal Au-Te deposit is currently mined for Au and 75% are recovered from Au-tellurides and pyrite. Tellurium has been processed in the past, but is now sent to tailings despite of concentrations reaching 1.4 wt. % in pyrite, which makes this system a natural laboratory to investigate key Te enrichment processes. The epithermal mineralisation at Vatukoula consists of an early low-grade disseminated host-rock and a later high-grade Ag-Au-Te vein-type stage. Pyrite occurs in both ore-types with diverse As contents including concentrations < 0.5 wt. % in pure pyrite, 0.5 to 13 wt. % in low-As and 23 to 43 wt. % in high-As pyrite, reflecting increasing fluid As with system evolution towards the high-grade mineralisation. Tellurium contents in pyrite increase from pure pyrite (up to 220 ppm) to low-As pyrite (up to 1.4 wt. %), but with a decrease towards high-As pyrite (up to 185 ppm). This is a yet unknown relation, since trace element incorporation in pyrite is usually facilitated by increasing As. Instead, the presented results suggest a threshold between 13 and 23 wt. % As, above which the incorporation of Te and related elements (e.g., Ag, Au) may be less favourable. Mineral stabilities, trace element ratios (e.g., Sb/Pb, Tl/Pb) and LA-ICP-MS mapping of texturally distinct pyrite indicate that fluid boiling was a critical process for the Ag, Au and Te enrichment in the Vatukoula epithermal system. Fluid sulphidation states decreased with proceeding evolution of the epithermal system from initially intermediate- to late low-sulphidation conditions, which led to the diverse chemical character of pyrite. Early pure pyrite primarily formed as a replacement product of magnetite in the altered host rocks, whereas low- and high-As pyrite precipitated in the direct vicinity of Ag-Au-telluride veins, from which most of the As, Ag, Te and Au hosted in pyrite was derived from. Consequently, the trace element composition of pyrite allows the fingerprinting of the fluid evolution of Te-rich ore-forming systems like Vatukoula, Fiji.
Created from Fastlane, Scopus look-up
Keywords: As-Te incorporation; Epithermal alkaline hosted; LA-ICP-MS; Pyrite; Solid-solution; Vatukoula

Finite Element simulation of a slow moving natural slope in the Upper-Austrian Alps using a visco-hypoplastic constitutive model - Van Den Ham, Geeralt; Rohn, Joachim; Meier, Thomas; Czurda, Kurt (Geomorphology, 2009)
A large-size creeping natural slope was simulated with the Finite Element (FE) method, using a visco-hypoplastic material model, which describes the mechanical behaviour of cohesive soils, allowing for viscous effects (i.e. creep, relaxation and rate-dependence of stiffness). First, the required material parameters were determined by means of standard geotechnical laboratory tests using representative soil samples taken from the slope. Then a FE mesh of a slope section was constructed and boundary conditions were established. The slope movements were simulated and compared with inclinometer measurements, which were available for a period of 16 years. The calculation results are in good agreement with the observed velocities. A parameter study was carried out in order to assess the influence of slope angle, initial void ratio, material parameters as well as their spatial distribution. © 2008 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.profes_3.finite
Keywords: Austrian Alps; Constitutive modelling; Creeping slope; Finite Element method; Visco-hypoplasticy

First dinosaur from the Isle of Eigg (Valtos Sandstone Formation, Middle Jurassic), Scotland - Panciroli, Elsa; Funston, Gregory F.; Holwerda, Femke Marleen; Maidment, Susannah C.R.; Foffa, Davide; Larkin, Nigel; Challands, Tom; Depolo, Paige E.; Goldberg, Daniel; Humpage, Matthew; Ross, Dugald; Wilkinson, Mark; et al. (Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 2020)
Dinosaur body fossil material is rare in Scotland, previously known almost exclusively from the Great Estuarine Group on the Isle of Skye. We report the first unequivocal dinosaur fossil from the Isle of Eigg, belonging to a Bathonian (Middle Jurassic) taxon of uncertain affinity. The limb bone NMS G.2020.10.1 is incomplete, but through a combination of anatomical comparison and osteohistology, we determine it most likely represents a stegosaur fibula. The overall proportions and cross-sectional geometry are similar to the fibulae of thyreophorans. Examination of the bone microstructure reveals a high degree of remodelling and randomly distributed longitudinal canals in the remaining primary cortical bone. This contrasts with the histological signal expected of theropod or sauropod limb bones, but is consistent with previous studies of thyreophorans, specifically stegosaurs. Previous dinosaur material from Skye and broadly contemporaneous sites in England belongs to this group, including Loricatosaurus and Sarcolestes and a number of indeterminate stegosaur specimens. Theropods such as Megalosaurus and sauropods such as Cetiosaurus are also known from these localities. Although we find strong evidence for a stegosaur affinity, diagnostic features are not observed on NMS G.2020.10.1, preventing us from referring it to any known genera. The presence of this large-bodied stegosaur on Eigg adds a significant new datapoint for dinosaur distribution in the Middle Jurassic of Scotland.
CRIS-Team Scopus Importer:2020-10-23
Keywords: Bathonian; Great Estuarine Group; histology; Sauropoda; Theropoda; Thyreophora

First documentation of Middle Ordovician warm-water carbonates in the Mount Jolmo Lungma (Mount Everest) area, southern Xizang (Tibet), China, and its paleogeographic implications - Yu, Shenyang; Fang, Xiang; Munnecke, Axel; Li, Wenjie; Zhen, Yongyi; Li, Yue; Wang, Zhihao; Zhang, Yuandong (Palaeogeography, Palaeoclimatology, Palaeoecology, 2019)
A Middle Ordovician limestone succession, representing part of the Alai Formation (middle part of the Chiatsun Group) of the Himalayan Orogenic Belt, is well exposed at Jiacun section in Nyalam County to the west of the Mount Jolmo Lungma (Mount Everest), southern Xizang (Tibet), China. The succession, though reported previously, has yet to be investigated in detail, especially in the aspects of precise dating, stratigraphic correlation and its paleogeographical affinities. In this contribution we document for the first time the conodont biostratigraphy, carbon isotope chemostratigraphy and microfacies analyses of this carbonate succession. The conodont fauna indicates a middle Darriwilian (Middle Ordovician) age corresponding to the Histiodella holodentata Biochronozone. The carbon isotope records have shown minor fluctuations of δ13C values, with only a small negative carbon excursion in the lower part. The microfacies analysis has resulted in the identification of seven microfacies, including micritic limestone, lithoclastic packstone, non-skeletal grainstone, bioclastic limestone, bioclastic-lithoclastic limestone, bioclastic-lithoclastic-oncoid limestone, and bioclastic-lithoclastic-oncoid-ooid limestone. From thin sections, fragments of crinoids, brachiopods, gastropods, trilobites, bryozoans and calcareous algae are identified. Abundant lithoclasts, cortoids, peloids, oncoids and ooids, together with the occurrences of dasyclad algae and hardgrounds, are also recognized, indicating a shallow- and warm-water marine environment, and a likely tropical or subtropical affinity. Comparison of the lithofacies and faunas of this limestone succession of the Alai Formation with coeval strata in the Zanskar-Spiti area (northern India), Nepal, Bhutan, Canning Basin (West Australia), Lhasa, Qiangtang, Sibumasu, Tarim and North China, suggests that during the Darriwilian these regions or terranes may have possessed a warm-water marine environment and were located in low-latitudinal zones. It seems likely that this region of the northeastern Gondwana and peri- Gondwana was protected from substantial influx of cool-water currents derived from high latitudes at that time.<br
Keywords: Carbonate microfacies; Chemostratigraphy; Conodont biostratigraphy; Darriwilian; Himalaya; Paleogeography

First evidence of eclogite facies metamorphism in the Shackleton Range, Antarctica: Trace of a suture between East and West Gondwana? - Schmädicke, Esther; et al. (Journal of Metamorphic Geology, 2006)
Keywords: Eclogite facies metamorphism; Antarctica; Shackleton Range; Pan-African; Ultramafic rocks

First indications of seasonal and spatial variations of water sources in pine trees along an elevation gradient in a Mediterranean ecosystem derived from δ18O - Szymczak, Sonja; Barth, Johannes; Bendix, Jörg; Huneau, Frédéric; Garel, Emilie; Häusser, Martin; Juhlke, Tobias; Knerr, Isabel; Santoni, Sébastien; Mayr, Christoph; Trachte, Katja; van Geldern, Robert; et al. (Chemical Geology, 2020)
Water availability is the most important factor for the vitality of forest ecosystems, especially in dry environments. The Mediterranean region is one of the hotspots of future climate change; therefore, data on the water cycle are urgently needed. We measured oxygen isotope compositions in creek water, precipitation, stem water, needle water, and tree-ring cellulose over one growing season to establish the relationship between isotope compositions in different compartments along a fractionation pathway. We analyzed plant material from pine trees (Pinus nigra J.F. Arn subsp. laricio (Poiret) Maire var. Corsicana Hyl. and Pinus pinaster Aiton) at five locations along an elevation gradient from sea level to 1600 m asl. We traced back the oxygen isotope composition from source to sink in tree-ring cellulose in order to identify the water sources used by the trees, and to quantify the extent of isotope fractionation processes. Our results showed that the trees used different water sources over the course of the growing season, ranging from winter snow meltwater to summer precipitation at higher sites and deep soil water reservoirs at coastal sites. Needle water enrichment was higher at higher elevation sites than at coastal locations, highlighting the importance of site-specific climate conditions on the isotopic composition values in tree material. Water availability seems to be most restricted at the highest site, making these trees most vulnerable to climate change.
CRIS-Team Scopus Importer:2020-06-09
Keywords: Needle water enrichment; Oxygen isotopes; Pinus nigra; Pinus pinaster; Water source; Xylem water

First record of coralline demosponges in the Pleistocene: implications for reef ecology - Kießling, Wolfgang; et al. (Coral Reefs, 2009)
We report the first discovery of coralline sponges from Pleistocene reef limestones of Vanuatu. Sponges of the genus Acanthochaetetes were identified from two reef terraces of Middle and Late Pleistocene age. As these sponges document cryptic habitats in modern coral reefs, they may be index fossils of cryptic habitats in the Pleistocene as well, thereby providing clues on growth conditions in fossil reefs. The small size of the discovered specimens may be attributed to the transient nature of their cryptic habitats, either due to reef growth or the occurrence of an unusual event. © Springer-Verlag 2009.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.LP.firstr
Keywords: Acanthochaetetes; Chaetetidae; Cryptic habitat; Demospongiae; Pleistocene; Reef growth

First record of stable isotopes (δ13C, δ18O) and element ratios (Mg/Ca, Sr/Ca) of Middle to Late Jurassic belemnites from the Indian Himalayas and their potential for palaeoenvironmental reconstructions - Alberti, Matthias; Fürsich, Franz; Pandey, Dhirendra K.; Andersen, Nils; Garbe-Schönberg, Dieter; Bhosale, Suraj; Chaskar, Ketan; Habermann, Jörg (Journal of Palaeogeography, 2021)
Middle to Late Jurassic belemnites from the Spiti and Zanskar valleys in the Indian Himalayas were used for stable isotope (δ13C, δ18O) and element (Mg/Ca, Sr/Ca) analyses. Although the Himalayan orogeny deformed and altered a large portion of the collected fossils, cathodoluminescence and scanning electron microscopy in combination with analyses of iron and manganese contents allowed the identification of belemnites believed to still retain their original chemical composition. Results indicate a long-term temperature decrease from the Middle Callovian–Oxfordian to the Tithonian, which is proposed to have been caused by a concomitant drift of eastern Gondwana into higher palaeolatitudes. Reconstructed absolute temperatures depend on the used equation and assumed δ18O value of seawater, but most likely varied between 17.6 °C to 27.6 °C in the Kimmeridgian and Tithonian with average values between 22 °C to 24 °C. This way, temperatures were similar to slightly warmer than today at comparable latitudes. The reconstruction of absolute temperatures for the Middle Callovian–Oxfordian was hindered by a larger number of poorly preserved belemnites representing this time interval.
CRIS-Team Scopus Importer:2021-09-10
Keywords: Eastern Gondwana; India; Jurassic; Palaeoclimate; Spiti; Tethyan Himalaya; Water temperature; Zanskar

First record of the Early Devonian ammonoid Teicherticeras from the Eifel (Germany): biogeographic and biostratigraphic importance - Übelacker, Christof; Jansen, Ulrich; de Baets, Kenneth (Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, 2016)
We herein report the discovery of Teicherticeras cf. teicherti in the lower Emsian of the Eifel region (Germany), which is important for the correlation of the neritic Rhenish facies and the hemipelagic Hercynian facies as well as the alignment of regional brachiopod biozonation with global ammonoid biostratigraphy. The specimens are similar in morphology and ornamentation to early Teicherticeras species like T. senior and particularly T. teicherti. The temporal overlap of Anetoceras and Teicherticeras indicates a correlation of the Neichnerberg Formation with the upper part of the Praecursor Zone and lower part of the Barrandei Zone. Interestingly, Teicherticeras is also more widely distributed than Anetoceras, which might be related with its better dispersal capabilities and/or sampling biases against Anetoceratinae.
Keywords: Ammonoidea; Teicherticeratidae; Devonian; Emsian; Rhenish Mountains; biostratigraphy; biogeography

First record of the early Sheinwoodian carbon isotope excursion (ESCIE) from the Barrandian area of northwestern Perigondwana. - Fryda, Jiri; Lehnert, Oliver; Joachimski, Michael (Estonian Journal of Earth Sciences, 2015)
UnivIS-Import:2015-07-08:Pub.2015.nat.dgeo.IGM.LG.firstr

First record of the Middle Darriwilian δ13C excursion (MDICE) in southern Xizang (Tibet), China, and its implications - Yu, Shenyang; Fang, Xiang; Zhang, Yuandong; Zhen, Yong Yi; Li, Wenjie; Li, Yue; Munnecke, Axel (Carbonates and Evaporites, 2021)
The Ordovician Chiatsun Group, exposed at the Jiacun section, Nyalam, in southern Xizang (Tibet), China, is biostratigraphically one of the best constrained Ordovician sections in the Himalaya margin, and thus plays a key role in correlating the Ordovician strata of this region. The Chiatsun Group is subdivided into the Adang Formation, the Alai Formation, and the Jiaqu Formation, in stratigraphically ascending order. Based on limestone samples collected from the Alai and Jiaqu formations, the Darriwilian chemostratigraphy is established and confirmed by conodont biozonation data. The Middle Darriwilian δ13C excursion (MDICE) is recorded in the Himalaya margin for the first time, with an amplitude of about 2‰. Its rising limb starts near the boundary of the Histiodella holodentata and Histiodella kristinae zones, and the excursion reaches its maximum values in the Pygodus serra Zone. The decreasing limb is not exposed. The carbon isotope curve with its pronounced onset of the MDICE documents a high potential for chemostratigraphic correlations helping to disentangle the Kurgiakh orogeny in the Himalaya margin. The MDICE recorded in southern Xizang correlates well with that in Baltoscandia, Laurentia, the Argentine Precordillera, Siberia, South China, North China, and Tarim, and extends the distribution of the MDICE to a new block, and thereby strengthens its global significance.
CRIS-Team Scopus Importer:2021-07-02
Keywords: Carbon isotope stratigraphy; Chiatsun Group; Darriwilian of Ordovician; Himalaya margin; Kurgiakh orogeny

First records of Asbestopluma hypogea Vacelet and Boury-Esnault, 1996 (Porifera, Demospongiae, Cladorhizidae) on seamounts and in bathyal settings of the Mediterranean Sea - Aguilar, Ricardo; López Correa, Matthias; Calcinai, Barbara; Pastor, Xavier; de la Torriente, Ana; Garcia, Silvia (Zootaxa, 2011)
The carnivorous sponge Asbestopluma hypogea, was known only from shallow submarine caves (-15 to -26 m) in the Western Mediterranean Sea and the Adriatic. Herein A. hypogea is reported from outside of caves, on seamounts in the Alboran Sea (-167 m), off the Balearics (-100 m) and north off Sicily (-660 m), and along steep bathyal escarpments in the Strait of Sicily (∼700 m). These deeper ROV-based findings of A. hypogea are conform to the typical deep-sea occurrence of the Cladorhizidae. Copyright © 2011 Magnolia Press.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LP.firstr
Keywords: Carnivorous sponges; Cladorhizidae; Western mediterranean

First report of Archaeoscyphia rectilinearis (Porifera) from the Wenlock of Gotland, Sweden - Rhebergen, Freek; Munnecke, Axel; Jarochowska, Emilia (GFF, 2016)
A specimen of the orchocladinid sponge Archaeoscyphia rectilinearis de Freitas (1989) is presented here as the first representative of the Anthaspidellidae from Wenlock strata on Gotland (Sweden). Other coeval occurrences are not yet known from the Silurian of Baltica. This specimen forms a link between the recently described sponge assemblage from Llandovery (Telychian) strata on Gotland and those from Wenlock to Ludlow strata from Arctic Canada. In addition, the specimen fills a gap in the fossil record of Silurian non-stromatoporoid sponges, which are poorly known worldwide.
Keywords: Demospongea; Gotland; Orchocladina; Porifera; Silurian; Wenlock

Five million years of high atmospheric CO2 in the aftermath of the Permian-Triassic mass extinction - Joachimski, Michael; Müller, Johann; Gallagher, Timothy; Mathes, Gregor; Chu, Daoliang; Mouraviev, Fedor; Silantiev, Vladimir; Sun, Yadong; Tong, Jinnan (Geology, 2022)
The end-Permian mass extinction, the largest biological crisis in Earth history, is currently understood in the context of Siberian Traps volcanism introducing large quantities of greenhouse gases to the atmosphere, culminating in the Early Triassic hothouse. In our study, the late Permian and Early Triassic atmospheric CO2 history was reconstructed by applying the paleosol pCO2 barometer. Atmospheric pCO2 shows an approximate 4× increase from mean concentrations of 412–919 ppmv in the late Permian (Changhsingian) to maximum levels between 2181 and 2610 ppmv in the Early Triassic (late Griesbachian). Mean CO2 estimates for the later Early Triassic are between 1261–1936 ppmv (Dienerian) and 1063–1757 ppmv (Spathian). Significantly lower concentrations ranging from 343 to 634 ppmv are reconstructed for the latest Early to Middle Triassic (Anisian). The 5 m.y. episode of elevated pCO2 suggests that negative feedback mechanisms such as silicate weathering were not effective enough to reduce atmospheric pCO2 to precrisis levels and that marine authigenic clay formation (i.e., reverse weathering) may have been an important component of the global carbon cycle keeping atmospheric pCO2 at elevated levels.<br

Fluctuations in the carbonate production of Phanerozoic reefs - Kießling, Wolfgang; Flügel, Erik; Golonka, Jan (Carbonate platform systems: components and interactions, 2000)
A comprehensive database on Phanerozoic reefs is used to evaluate the carbonate production of reefs through time. Net, gross and export carbonate productions of 2760 Phanerozoic reefs are calculated and the cumulative production for 32 time slices is evaluated. The total amount of carbonate produced in the reef ecosystem in a given time slice is a function of global reef abundance, average reef size and the relative amount of carbonate exported from the reefs. Carbonate production of reefs is usually low, but characterized by prominent peaks in the mid-Silurian Givetian-Frasnian, the Late Triassic, the Late Jurassic, the mid-Cretaceous and the Neogene. The determinants of reefal carbonate production are correlated with a variety of intrinsic and extrinsic parameters such as palaeogeographic setting, dominant biota, reef type, bioerosion, petrographic composition, eustatic sea level, oceanic crust production rates, atmospheric CO 2 concentrations, and global nutrient level. The calculated carbonate production, however, is rarely correlated with particular Earth system parameters. This implies that either the controls on reefal carbonate production are too complex to allow reliable predictions, or biotic factors represent more important controls than physico-chemical parameters. The constructed curve of Phanerozoic reefal carbonate export production is also poorly correlated with proposed curves of global shallow-water carbonate production suggesting that reefs rarely contributed in a quantitatively significant way to the global carbonate budget.
UnivIS-Import:2015-04-20:Pub.2000.nat.dgeo.IGM.LP.fluctu

Fluid flow, alteration and mineralisation associated with the emplacement of the Lycian nappes (SW Turkey). - Joachimski, Michael; et al. (Journal of Geochemical Exploration, 2003)
Associated with the emplacement of the Lycian nappes, SW Turkey, Cretaceous limestones were thrusted over an ophiolitic mélange in their front zone. Miocene flysch formed immediately in front of these nappes and were overthrusted by the Lycian nappes. Petrographic and stable isotope evidence demonstrates that fluid circulation in the allochthonous limestones was rock-buffered and restricted. The thrust contact between the ophiolitic mélange and the overlying limestones is characterised by an alteration with hematitisation, dolomitisation, silicification and intense calcite veining. Although this alteration indicates an upward fluid flux from the ophiolitic mélange, the stable isotopic composition of the calcite veins in the altered zone does not reflect a major migration across the thrust fault. In contrast, extensive ferroan calcite veins developed in the flysch deposits as the result of the expulsion of seawater trapped in the pores during thrusting and/or sedimentation. © 2003 Elsevier Science B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2003.nat.dgeo.IGM.LG.journa
Keywords: Cataclasis; Fe-mineralisation; Lycian nappe; Palaeofluid flow; Stable isotope geochemistry

Fluid inclusion and microfabric studies on Zechstein carbonates (Ca2) and related fracture mineralizations – New insights on gas migration in the Lower Saxony Basin (Germany) - Duschl, Florian; Van Den Kerkhof, Alfons; Sosa, Graciela; Leiss, Bernd; Wiegand, Bettina; Vollbrecht, Axel; Sauter, Martin (Marine and Petroleum Geology, 2016)
Keywords: Basin evolution; Fluid inclusions; Gas migration; Lower Saxony Basin; Fluorite; Fracture mineralization; Microfabrics; Stassfurt carbonate

Fluid Inclusions and Stable Isotopic Characteristics of the Yaoling Tungsten Deposit in South China: Metallogenetic Constraints - Yang, Feng; Zhai, Wei; Sun, Xiaoming; Klemd, Reiner; Sun, Yanyan; Wu, Yunshan; Hua, Renmin; Zheng, Siqi (Resource Geology, 2019)
The Yaoling tungsten deposit is a typical wolframite quartz vein-type tungsten deposit in the South China metallogenic province. The wolframite-bearing quartz veins mainly occur in Cambrian to Ordovician host rocks or in Mesozoic granitic rocks and are controlled by the west-north-west trending extensional faults. The ore mineralization mainly comprises wolframite and variable amounts of molybdenite, chalcopyrite, pyrite, fluorite, and tourmaline. Hydrothermal alteration is well developed at the Yaoling tungsten deposit, including greisenization, silicification, fluoritization, and tourmalinization. Three types of primary/pseudosecondary fluid inclusions have been identified in vein quartz, which is intimately intergrown with wolframite. These include two-phase liquid-rich aqueous inclusions (type I), two- or three-phase CO2-rich inclusions (type II), and type III daughter mineral-bearing multiphase high-salinity aqueous inclusions. Microthermometric measurements reveal consistent moderate homogenization temperatures (peak values from 200 to 280 degrees C), and low to high salinities (1.3-39 wt % NaCl equiv.) for the type I, type II, and type III inclusions, where the CO2-rich type II inclusions display trace amounts of CH4 and N-2. The ore-forming fluids are far more saline than those of other tungsten deposits reported in South China. The estimated maximum trapping pressure of the ore-forming fluids is about 1230-1760 bar, corresponding to a lithostatic depth of 4.0-5.8 km. The delta D-H2O isotopic compositions of the inclusion fluid ranges from -66.7 to -47.8 parts per thousand, with delta O-18(H2O) values between 1.63 and 4.17 parts per thousand, delta C-13 values of -6.5-0.8 parts per thousand, and delta S-34 values between -1.98 and 1.92 parts per thousand, with an average of -0.07 parts per thousand. The stable isotope data imply that the ore-forming fluids of the Yaoling tungsten deposit were mainly derived from crustal magmatic fluids with some involvement of meteoric water. Fluid immiscibility and fluid-rock interaction are thought to have been the main mechanisms for tungsten precipitation at Yaoling.
CRIS-Team WoS Importer:2019-04-09
Keywords: fluid inclusion; immiscibility; stable isotope; Yaoling tungsten deposit

Fluid-mediated metal transport in subduction zones and its link to arc-related giant ore deposits: Constraints from a sulfide-bearing HP vein in lawsonite eclogite (Tianshan, China). - Li, Jilei; Gao, Jun; John, Timm; Klemd, Reiner; Su, Wen (Geochimica Et Cosmochimica Acta, 2013)
High-pressure (HP) veins in eclogites provide insight into element mobility during fluid-rock interaction in subduction zones. Here, we present a petrological-geochemical study of a sulfide-bearing HP vein and its massive lawsonite eclogite host rock from the Chinese Tianshan (ultra-)high-pressure/low-temperature metamorphic belt. The omphacite-dominated vein is enveloped by a garnet-poor, sulfide-bearing eclogite-facies reaction selvage. Lawsonite, garnet, omphacite, glaucophane and other HP minerals occur as inclusions in pyrite porphyroblasts of the selvage rock, indicating that the selvage formed prograde under eclogite-facies conditions. Relicts of wall-rock garnet (Grt_I) cores in recrystallized selvage garnet (Grt_II) close to the wall rock and the Ca distribution in Grt_II, which images the overgrown selvage matrix, indicate that the selvage formed due to dissolution-precipitation processes as a consequence of fluid-rock interaction of the wall rock eclogite with the vein-forming fluid. The peak metamorphic P-T conditions of the wall-rock eclogite are estimated at ca. 590. °C and 23. kbar. Mass-balance calculations indicate that the reaction selvage experienced: (1) a depletion of the large-ion lithophile elements (K-Rb-Ba) of up to 100% relative to their concentrations in the wall-rock eclogite; (2) a moderate depletion of the HREE and some transition metal elements including Fe, Cu, Ni, Zn, Co, Cr, and Mn (10-40%); (3) a significant enrichment of CaO (up to 50-80%), Sr (up to 200%), Pb (up to 170%) and S (up to 210%); (4) a slight to moderate enrichment of the LREE (10-20%) and MREE (0-40%); whereas (5) the HFSE show no significant variations.The chemical changes in the selvage suggest that the fluid, which caused the dissolution of the wall-rock and the precipitation of the selvage assemblage while the vein formed, was probably a mixture of an "internal" fluid derived from the prograde dehydration (e.g., lawsonite breakdown) of the wall rock and an "external" fluid most likely derived from dehydrating altered oceanic crust located in stratigraphically lower units of the subducting slab. The external fluid introduced Ca, S, Sr, Pb and at least parts of the LREE and the MREE into the selvage, whereas some elements, such as the remaining LREE and MREE, may have been derived from the wall rock eclogite via diffusional transport into the selvage. The enrichment of Ca and L-MREE is displayed by the abundant growth of selvage epidote. In contrast, the dissolution of garnet and phengite released significant amounts of HREE and LILE (K-Rb-Ba) into the passing fluid, because the chemical changes within the selvage prevented the formation of a mineral assemblage with sufficiently high bulk-fluid partition coefficients for these elements. Significant amounts of transitional metal elements were released into the fluid during the dissolution of white mica and the dissolution-precipitation behavior of garnet, omphacite, dolomite and sulfides. Thus the LILE and HREE along with some transition metal elements (e.g., Fe, Cu, Ni and Zn) were mobilized during the dissolution-precipitation processes that led to the selvage formation. Accordingly the slab fluids are not only strongly enriched in LILE and depleted in HFSE, but also carry significant amounts of transition metals. It is most likely that slab fluids strongly contribute to the metal flux into the arc magma systems finally resulting in giant arc-related ore deposits. © 2013 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.c3geoc.fluidm

Fluorination of aza[60]fullerene - Boltalina, Olga V.; Drewello, Rainer; Hirsch, Andreas; Reuther, Uwe; Jorgensen, J. D.; Markov, V.; Taylor, Roger (Proceedings - Electrochemical Societ PV 99-12 Volume 7 Fullerenes. (Recent Adcances in the Chemistry and Physics of Fullerenes and Related Materials), 1999)

Fluorophlogopite-bearing and carbonate metamorphosed xenoliths from the Campanian Ignimbrite (Fiano, southern Italy): Crystal chemical, geochemical and volcanological insights - Lacalamita, M.; Balassone, G.; Schingaro, E.; Mesto, E.; Mormone, A.; Piochi, M.; Ventruti, G.; Joachimski, Michael (Mineralogical Magazine, 2017)
Keywords: Campanian Ignimbrite; Crystal chemistry; Fiano xenoliths; Fluorophlogopite; Geochemistry; Southern Italy

Fluvial-aeolian sedimentary facies, Sossusvlei, Namib Desert - Feder, Amelie; Zimmermann, Robert; Stollhofen, Harald; Caracciolo, Luca; Garzanti, Eduardo; Andreani, Lois (Journal of Maps, 2018)
Aeolian sedimentary processes and corresponding facies shape the Earth’s surface and control the evolution of dune fields. The Namib Sand Sea with its Sossusvlei playa-lake is a perfect example to investigate the spatial distribution of fluvially influenced aeolian deposits. Remote sensing in combination with ground observations allowed for mapping of the facies distribution pattern of associated fluvial and aeolian sediments. Laboratory spectral signature measurements were used to further improve the separation between six groups of facies: modern aeolian sand, deflation surface, mud pool/mud drapes, heavy mineral lag, reworked fluvial–aeolian sediments, and fossil dune remnant. The best results were achieved through a supervised classification algorithm trained by field observations, a combination of Principal Component Analysis, band ratios, texture and geomorphologic indices. Consequently, a map outlining the facies distribution pattern of the Sossusvlei area at a scale of 1:10,000 was created. We propose this as a possible workflow to efficiently map and monitor desert environments and to investigate the interplay of aeolian and fluvial sediments.<br
Keywords: Sossus sand formation; world view 3; dune river interaction; modern sediments; facies mapping; Quaternary

Fly-ash-based geopolymers: How the addition of recycled glass or red mud waste influences the structural and mechanical properties - Toniolo, Nicoletta; Taveri, Gianmarco; Hurle, Katrin; Roether, Judith; Ercole, P; Dlouhy⁠, Ivo; Boccaccini, Aldo R. (Journal of Ceramic Science and Technology, 2017)
Keywords: Fly ash; Geopolymers; Red mud; Waste glass

Fog-low stratus (FLS) regimes on Corsica with wind and PBLH as key drivers - Knerr, Isabel; Trachte, Katja; Egli, Sebastian; Barth, Johannes; Bräuning, Achim; Garel, Emilie; Häusser, Martin; Huneau, Frederic; Juhlke, Tobias; Santoni, Sebastien; Szymczak, Sonja; van Geldern, Robert; et al. (Atmospheric Research, 2021)
The French Mediterranean island of Corsica is already today confronted with a clear tendency towards water shortage, leading not only to socio-economical, but also to ecological problems. A potential, but not very widespread source of water is the presence of near-ground clouds, mostly fog. In this study, we investigate foglow stratus (FLS) frequencies in Corsica, derived from a data set of Meteosat Second Generation SEVIRI, whereby a distinction between fog and low stratus is hardly feasible using remote sensing data. The FLS frequency was studied with respect to its interaction with distinct locally-generated wind and its dependence on the planetary boundary layer height (PBLH) obtained by ERA5 reanalysis (the fifth generation of the European Centre for Medium-Range Weather Forecasts, ECMWF). Results show that radiation FLS is formed in coastal areas at sunrise, with low PBLH. On the other hand, in the interior of the island at sunset, a maximum of advection FLS is formed, fostered by locally-generated and related transport of moisture. On the east side of the island, FLS frequency is lower throughout the year due to frequent lee situations. This situation is reinforced by reduced synoptic moisture transport by westerly winds, so that westerly exposed slopes benefit from moisture input by FLS formation.
CRIS-Team WoS Importer:2021-08-13

Foraminifera from the Norian Rhaetian reef carbonates of the Taurus Mountains (Saklıkent, Turkey) - Senowbari-Daryan, Baba; Link, Michael (Geologica Carpathica, 2017)
Norian–Rhaetian reef carbonates are exposed in several localities in Taurus Mountains. They predominately contain hypercalcified sponges, followed by scleractinian corals and other less numerous organisms. A coherent Norian–Rhaetian reef structure is exposed near the small town of Saklıkent, west of Antalya. Foraminifers occur in reef carbonates of Saklıkent by numerous genera as shown in this paper. Two species — Siculocosta taurica and Siculocosta sadati — are described as new. The foraminiferal association of Saklıkent is similar or almost identical to the associations known from the Norian–Rhaetian reefs of Sicily, Northern Calcareous Alps, and Greece but shows less similarity to the foraminiferal association from the Apennines, Italy. The most abundant foraminifers are milioliporoids, particularly galeanellids and cucurbitids. Some sessile and agglutinated foraminifers, including Alpinophragmium perforatum Flügel, which mostly occurs abundantly in the Norian–Rhaetian reef carbonates, could not be found in the Saklıkent reef. This association of foraminifera is reported for the first time from a Norian–Rhaetian reef in the Taurus Mountains of Turkey.
UnivIS-Import:2017-11-07:Pub.2017.nat.dgeo.IGM.LP.forami
Keywords: Foraminifera; Upper Triassic; reef; Saklıkent; Taurus Mountains; Turkey

Formation conditions and REY enrichment of the 2060 Ma phosphorus mineralization at Schiel (South Africa): geochemical and geochronological constraints - Graupner, Torsten; Klemd, Reiner; Henjes-Kunst, Friedhelm; Goldmann, Simon; Behnsen, Helge; Gerdes, Axel; Dohrmann, Reiner; Barton, J. M.; Opperman, Rehan (Mineralium Deposita, 2018)
Rocks of the rare-earth element (REY)-enriched apatite deposit in the eastern part of the Schiel Alkaline Complex (SAC; Southern Marginal Zone, Limpopo Belt) were studied for their whole-rock and mineral chemistry, REY mineral distribution and geochronology. Apart from phoscorite (sensu lato), pyroxenite and various syenitic rock types with quite variable apatite contents display P-REY enrichments. Field observations, mineralogical composition as well as major and trace element chemistry of soils make it possible to constrain the distribution of the hidden P-REY-rich rock types in the apatite deposit. Uranium-lead ages of zircon from phoscorite (sensu lato) and syenite are in the range of 2.06–2.05 Ga. Samarium-neodymium (εNd(t) −8.6 to −6.0) and in part Rb-Sr (87Sr/86Sr(t) 0.70819–0.70859) isotope data for whole-rock samples and mineral separates indicate an origin from an isotopically enriched and slightly variable source. Fluorapatite, early allanite and titanite are the main REY carriers at Schiel. Fluorapatite dominates the REY budget of pyroxenite and phoscorite, whereas early allanite hosts most of the REY in syenite. Three apatite types are distinguished based on their occurrence in the rocks, REYtotal contents and colouration in cathodoluminescence microscopy. Magmatic apatite in pyroxenite and in phoscorite (sensu lato) as well as early stage type I/II apatite in syenitic rocks have moderate to high REYtotal abundances (up to 3.2 wt%) with the mineral enriched in light REE. Early ferriallanite-(Ce) is strongly enriched in light REE and shows very high REYtotal values (13.7–26.4 wt%), while late allanite has lower REYtotalconcentrations (6.9–14.9 wt%). Titanite is abundant in most syenitic rocks (REYtotal 1.7–6.4 wt%); chevkinite-(Ce) occurs locally and contributes to an REY enrichment in contact aureoles between syenite and different lithologies. Apatite-enriched rocks in the SAC in part contain significantly higher REYtotal concentrations in apatite grains compared to those in apatite-mineralized pyroxenite, phoscorite and carbonatite from Phalaborw
Keywords: Schiel Alkaline Complex; Apatite-mineralized rocks; Soil geochemistry; Rare-earth elements; U-Pb; Lu-Hf; Sm-Nd and Rb-Sr isotopic compositions; Cathodoluminescence

Formation of andesite melts and Ca-rich plagioclase in the submarine Monowai volcanic system, Kermadec arc - Kemner, Fabian; Haase, Karsten; Beier, Christoph; Krumm, Stefan; Brandl, Philipp (Geochemistry Geophysics Geosystems, 2015)
Andesites are typical rocks of island arcs and may either form by fractional crystallization processes or by mixing between a mafic and a felsic magma. Here we present new petrographic and geochemical data from lavas of the submarine Monowai volcanic system in the northern Kermadec island arc that display a continuous range in composition from basalt to andesite. Using petrology, major, trace, and volatile element data, we show that basaltic magmas mostly evolve to andesitic magmas by fractional crystallization. Our thermobarometric calculations indicate that the formation of the large caldera is related to eruption of basaltic-andesitic to andesitic magmas from a magma reservoir in the deeper crust. Small variations in trace element ratios between the caldera and the large active cone imply a homogeneous mantle source. Contrastingly, resurgent dome melts of the caldera stagnated at shallower depths are more depleted and show a stronger subduction input than the other edifices. The Monowai basaltic glasses contain less than 1 wt % HO and follow typical tholeiitic fractionation trends. High-An plagioclase crystals observed in the Monowai lavas likely reflect mixing of HO-saturated melt batches with hot and dry tholeiitic, decompression melt batches. The result is a relatively HO-poor mafic magma at Monowai implying that partial melting of the mantle wedge is only partly due to the volatile flux and that adiabatic melting may play a significant role in the formation of the parental melts of the Monowai volcanic system and possibly other arc volcanoes.
Keywords: fractional crystallization; glass; plagioclase; subduction; Tonga-Kermadec; volatiles

Formation of deglacial microbialites in coral reefs off Tahiti (IODP 310) involving sulfate-reducing bacteria - Heindel, Katrin; Birgel, Daniel; Peckmann, Joern; Kuhnert, Henning; Westphal, Hildegard (Palaios, 2010)
Keywords: coral reef; LA-ICP-MS; last sea-level rise; lipid biomarker; organomineralization

Formation of hydrate spheres in ternary binder systems - Götz-Neunhoeffer, Friedlinde; Zubriggen, Roger (Zkg International, 2008)
This study examines the hydration kinetics of hydrate-sphere formation. This is a form of heterogeneous setting and can frequently be observed in ternary binder mixtures high in Portland cement and containing calcium aluminate cement and CaSO4, which are retarded by means of tartaric acid. In many cases, the phenomenon of hydrate-sphere formation is the result of aging of the dry mix - quick-setting ternary binder mixtures, in particular, are severely prone to pre-hydration once the package has been opened. Formation of hydrate spheres can be eliminated only to a limited extent via minor adjustments of the formulation, with the result, ultimately, that the formulator is in many cases obliged to reevaluate the entire mineral binder system, including the retarder-accelerator system.
UnivIS-Import:2015-03-09:Pub.2008.nat.dgeo.IGM.LM.format

Formation of island arc dacite magmas by extreme crystal fractionation: An example from Brothers Seamount, Kermadec Island Arc (SW Pacific). - Haase, Karsten; Stroncik, Nicole; Garbe-Schönberg, Dieter; Stoffers, Peter (Journal of Volcanology and Geothermal Research, 2006)
Dacitic to rhyolitic glasses from Brothers Seamount in the southern Kermadec island arc lie on very tight major element trends and have formed by fractional crystallization from a basaltic magma rather than by partial melting of amphibolitic lower crustal rocks. The radiogenic isotope and highly incompatible element ratios of the dacites resemble the composition of basalts from other volcanoes in the same segment of the island arc which probably represent analogues to the basaltic parental magma of the Brothers Seamount lavas. Glass compositions show that the magmas did not degas extensively but retained much of their volatile inventory with very high Cl (4000 to 7000 ppm) but low water contents (∼2 wt.%). The Cl / K of 0.25 is constant in the Brothers Seamount lavas and probably reflects the composition of a sedimentary slab component in the subarc mantle below the volcano. The Brothers Seamount Cl / K reflects a sedimentary fluid rather than a melt and is lower than the Cl / K observed in Valu Fa Ridge lavas showing an influence of subducted altered basaltic crust, probably due to the higher K contents of sediments than in basalts. © 2005 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2006.nat.dgeo.IGM.legeo.format
Keywords: dacites; degassing; rhyolites; slab component; subduction; volatile elements

Formation of ore minerals in metamorphic rocks of the German continental deep drilling site (KTB) - de Wall, Helga; et al. (Journal of Geophysical Research. Solid Earth, 1997)

Formation of the Troodos Ophiolite at a triple junction: Evidence from trace elements in volcanic glass - Regelous, Marcel; Haase, Karsten; Freund, Sarah; Keith, Manuel; Weinzierl, Christoph; Beier, Christoph; Brandl, Philipp; Endres, T.; Schmidt, H. (Chemical Geology, 2014)
Fresh volcanic glasses from the extrusive section of the Troodos Ophiolite in Akaki Canyon are tholeiitic and basaltic to dacitic in composition. Compared to normal MORB they have extremely low fractionation corrected Na8, Fe8 and Ti8 and are enriched in fluid-mobile trace elements, including U, Ba, Rb, Sr and Pb, relative to non-fluid mobile elements of similar incompatibility. Trace element compositions of Akaki lavas define an array extending between ‘back-arc lava’-like compositions, and the field defined by Troodos boninites from the upper part of the lava sequence. Troodos lavas were derived from a mantle source that underwent early melt depletion, and later enrichment by both fluids and small degree melts. These processes can explain the unusual negative correlation of Pb/Ce with Zr/Nb and Ba/Nb in Troodos extrusives. Although some Troodos lavas are similar in composition to lavas from back-arc spreading centres, the boninites from the upper parts of the lava pile do not appear to have exact compositional equivalents among lavas from fore-arcs, back-arcs or other tectonic settings where similar rocktypes have been recovered. We suggest that the geochemical evolution inferred for the mantle source of Troodos lavas, together with geological evidence is most consistent with an origin for the Troodos Ophiolite at a spreading centre close to a ridge–trench–trench, or ridge–trench–transform triple junction, where highly depleted, subduction-modified, fluid-enriched mantle wedge material was able to upwell and decompress to shallow depths in a ‘fore-arc’ location. In such a tectonic setting, arc volcanism is captured by the spreading centre, explaining the lack of evidence for subaerial arc magmatism in Troodos. Rapid lateral migration of the triple junction could account for the similar ages of other Tethyan supra-subduction zone ophiolites.Fresh volcanic glasses from the extrusive section of the Troodos Ophiolite in Akaki Canyon are tholeiitic and basaltic to dacitic in composition. Compared to normal MORB they have extremely low fractionation corrected Na, Fe and Ti and are enriched in fluid-mobile trace elements, including U, Ba, Rb, Sr and Pb, relative to non-fluid mobile elements of similar incompatibility. Trace element compositions of Akaki lavas define an array extending between 'back-arc lava'-like compositions, and the field defined by Troodos boninites from the upper part of the lava sequence. Troodos lavas were derived from a mantle source that underwent early melt depletion, and later enrichment by both fluids and small degree melts. These processes can explain the unusual negative correlation of Pb/Ce with Zr/Nb and Ba/Nb in Troodos extrusives. Although some Troodos lavas are similar in composition to lavas from back-arc spreading centres, the boninites from the upper parts of the lava pile do not appear to have exact compositional equivalents among lavas from fore-arcs, back-arcs or other tectonic settings where similar rocktypes have been recovered. We suggest that the geochemical evolution inferred for the mantle source of Troodos lavas, together with geological evidence is most consistent with an origin for the Troodos Ophiolite at a spreading centre close to a ridge-trench-trench, or ridge-trench-transform triple junction, where highly depleted, subduction-modified, fluid-enriched mantle wedge material was able to upwell and decompress to shallow depths in a 'fore-arc' location. In such a tectonic setting, arc volcanism is captured by the spreading centre, explaining the lack of evidence for subaerial arc magmatism in Troodos. Rapid lateral migration of the triple junction could account for the similar ages of other Tethyan supra-subduction zone ophiolites. © 2014 Elsevier B.V.
Keywords: Ophiolite; Trace elements; Troodos; Volcanic glass

Formation of the Vergenoeg F-Fe-REE deposit (South Africa) by accumulation from a ferroan silicic magma - Brandt, Sönke; Klemd, Reiner; Haase, Karsten; Faßbender, Marc Lorin; Vennemann, Torsten (Journal of Petrology, 2020)

fossilbrush: An R package for automated detection and resolution of anomalies in palaeontological occurrence data - Flannery-Sutherland, Joseph T.; Raja, Nussaïbah Begum; Kocsis, Ádám; Kießling, Wolfgang (Methods in Ecology and Evolution, 2022)
Fossil occurrence databases are indispensable resources to the palaeontological community, yet present unique data cleaning challenges. Many studies devote significant attention to cleaning fossil occurrence data prior to analysis, but such efforts are typically bespoke and difficult to reproduce. There are also no standardised methods to detect and resolve errors despite the development of an ecosystem of cleaning tools fuelled by the concurrent growth of neontological occurrence databases. As fossil occurrence databases continue to increase in size, the demand for standardised, automated and reproducible methods to improve data quality will only grow. Here, we present semi-automated cleaning solutions to address these issues with a new R package fossilbrush. We apply our cleaning protocols to the Paleobiology Database to assess the prevalence of anomalous entries and the efficacy and impact of our methods. We find that anomalies may be effectively resolved by comparison against a published compendium of stratigraphic ranges, improving the stratigraphic quality of the data, and through methods which detect outliers in taxon-wise occurrence stratigraphic distributions. Despite this, anomalous entries remain prevalent throughout major clades, with often more than 30% of genera in major fossil groups (e.g. bivalves, echinoderms) displaying stratigraphically suspect occurrence records. Our methods provide a way to flag and resolve anomalous taxonomic data before downstream palaeobiological analysis and may also aid in the automation and targeting of future cleaning efforts. We stress, however, that our methods are semi-automated and are primarily for the detection of potential anomalies for further scrutiny, as full automation should not be a substitute for expert vetting. We note that some of our methods do not rely on external databases for anomaly resolution and so are also applicable to occurrences in neontological databases, expanding the utility of the fossilbrush R package.
CRIS-Team WoS Importer:2022-09-02

Fossil Focus: Ammonoids - de Baets, Kenneth; Hoffmann, René; Sessa, Jocelyn A.; Klug, Christian (Palaeontology [online], 2016)
Ammonoids (Ammonoidea) are an extinct group of marine invertebrates with an external shell. They were cephalopods, and hence closely related to modern cuttlefish, squid, octopuses and the pearly nautilus. In a non-scientific context, they are commonly called ammonites, but that term really includes only Jurassic and Cretaceous forms in its stricter scientific sense. The Ammonoidea as a whole lived from the Early Devonian to the earliest Palaeogene period, covering a timespan of about 350 million years. Normally, only their shells, also called conchs, or their internal moulds are found in the fossil record. Conchs from adult ammonoids range from about 5 millimetres to 2 metres in diameter. Due to the large diversity (taxonomic richness), disparity (morphological richness), nearly global distribution and abundance of their shells in the fossil record, ammonoids have been valued by geologists, palaeontologists, biologists and fossil collectors alike. They have been particularly useful for studies of biodiversity and for correlating and assigning relative ages to rocks (the field of biostratigraphy). Ammonoids have also proved valuable for studying the processes and patterns of evolution, because they repeatedly evolved towards more coiled, larger and/or more complex conchs. They probably had a large variety of life modes and reproductive strategies, but despite the widespread attention that they have received, there are still several controversies concerning the group’s palaeoecology, anatomy and evolutionary relationships.

Fossilien aus der Opalinuston-Formation von Mistelgau - Schulbert, Christian (Der Steinkern, 2013)
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LP.fossil
Keywords: Opalinuston-Formation; Mistelgau

Fossil intermediate-depth earthquakes in subducting slabs linked to differential stress release - Scambelluri, Marco; Pennacchioni, Giorgio; Gilio, Mattia; Bestmann, Michel; Plumper, Oliver; Nestola, Fabrizio (Nature Geoscience, 2017)
The cause of intermediate-depth (50-300 km) seismicity in subduction zones is uncertain. It is typically attributed either to rock embrittlement associated with fluid pressurization, or to thermal runaway instabilities. Here we document glassy pseudotachylyte fault rocks-the products of frictional melting during coseismic faulting-in the Lanzo Massif ophiolite in the Italian Western Alps. These pseudotachylytes formed at subduction-zone depths of 60-70 km in poorly hydrated to dry oceanic gabbro and mantle peridotite. This rock suite is a fossil analogue to an oceanic lithospheric mantle that undergoes present-day subduction. The pseudotachylytes locally preserve high-pressure minerals that indicate an intermediate-depth seismic environment. These pseudotachylytes are important because they are hosted in a near-anhydrous lithosphere free of coeval ductile deformation, which excludes an origin by dehydration embrittlement or thermal runaway processes. Instead, our observations indicate that seismicity in cold subducting slabs can be explained by the release of differential stresses accumulated in strong dry metastable rocks.

Fossilized leftover falls as sources of palaeoecological data: a ‘pabulite’ comprising a crustacean, a belemnite and a vertebrate from the Early Jurassic Posidonia Shale - Klug, Christian; Schweigert, Günter; Hoffmann, René; Weis, Robert; de Baets, Kenneth (Swiss Journal of Palaeontology, 2021)
Especially in Lagerstätten with exceptionally preserved fossils, we can sometimes recognize fossilized remains of meals of animals. We suggest the term leftover fall for the event and the term pabulite for the fossilized meal when it never entered the digestive tract (difference to regurgitalites). Usually, pabulites are incomplete organismal remains and show traces of the predation. Pabulites have a great potential to inform about predation as well as anatomical detail, which is invisible otherwise. Here, we document a pabulite comprising the belemnite Passaloteuthis laevigata from the Toarcian of the Holzmaden region. Most of its soft parts are missing while the arm crown is one of the best preserved that is known. Its arms embrace an exuvia of a crustacean. We suggest that the belemnite represents the remnant of the food of a predatory fish such as the shark Hybodus.
Created from Fastlane, Scopus look-up
Keywords: Anatomy; Belemnitida; Cephalopoda; Palaeoecology; Taphonomy; Toarcian

Fossil liberation: a model to explain high biodiversity in the Triassic Cassian Formation - Roden, Vanessa; Hausmann, Imelda M.; Nützel, Alexander; Seuß, Barbara; Reich, Mike; Urlichs, Max; Hagdorn, Hans; Kießling, Wolfgang (Palaeontology, 2019)
With 1429 animal species, the Triassic Cassian Formation in the Dolomites, Southern Alps (Italy), yields the highest species richness reported from any spatially constrained pre‐Quaternary formation known to science. The high preserved diversity is partly attributable to a high primary diversity governed by the tropical setting, increasing alpha diversity, and the breadth of habitats spurring beta diversity. More important is the excellent preservation of fossils and the ease with which they can be extracted from the poorly lithified sediments. We propose the term ‘liberation Lagerstätten’ to capture this preservational window. In contrast to conservation Lagerstätten, liberation Lagerstätten like the Cassian Formation originate from normal marine conditions but low‐grade diagenesis. Molluscs contribute substantially to species richness, comprising 67% of all invertebrate species in the Cassian Formation. The gastropod dominance (39% of all species) is nearly as great as in Recent tropical settings, contradicting the concept of a substantial Cenozoic rise.<br
Keywords: diversity; Cassian Formation; gastropod dominance; aragonite preservation; fossil

Fossil Parasites - de Baets, Kenneth; Littlewood, D. Timothy J. (Academic Press, 2015)
Parasitism is a dominant life history strategy and we know it has existed for millions of years. Detecting parasitism in the fossil record is problematic because we rarely see direct evidence and usually must rely on indirect evidence to infer its existence. This unique volume takes a broad and systematic view of direct and indirect evidence for parasitism in the fossil recor

Fossil Trafficking, Fraud, and Fakery - Raja Schoob, Nussaibah Begum; Dunne, Emma (Art Crime in Context, 2022)
The fascination with ancient flora and fauna is a centuries-old phenomenon and is one of the main drivers of fossil crimes. Fossils have been sought by the rich and famous since the advent of colonialism, propelling development in the field of palaeontology but also in how fossils make their way through various, sometimes illegal, corridors to end up in museums and collections across the world. As demand for fossils increased in the nineteenth century, so did commercial avenues for these objects that were being sold not only to private individuals but also to scientific institutions. The most complete and visually impressive fossils in terms of size or uniqueness determine the market value of these fossils with some selling for millions of United States dollars. This has also led to the tampering or forging of fossils by many dealers in an attempt to inflate prices. While fossil crimes have been prevalent for centuries, the legal frameworks within which these crimes can be controlled or stopped are regularly challenged or even circumvented not only due to the lack of enforcements of these regulations but also due to how paleontological objects are classified in the first place as well as other legal loopholes.<br

Fracturing and Porosity Channeling in Fluid Overpressure Zones in the Shallow Earth's Crust - Köhn, Daniel; Piazolo, Sandra; Sachau, Till; Toussaint, Renaud (Geofluids, 2020)
At the time of energy transition, it is important to be able to predict the effects of fluid overpressures in different geological scenarios as these can lead to the development of hydrofractures and dilating high-porosity zones. In order to develop an understanding of the complexity of the resulting effective stress fields, fracture and failure patterns, and potential fluid drainage, we study the process with a dynamic hydromechanical numerical model. The model simulates the evolution of fluid pressure buildup, fracturing, and the dynamic interaction between solid and fluid. Three different scenarios are explored: fluid pressure buildup in a sedimentary basin, in a vertical zone, and in a horizontal layer that may be partly offset by a fault. Our results show that the geometry of the area where fluid pressure is successively increased has a first-order control on the developing pattern of porosity changes, on fracturing, and on the absolute fluid pressures that sustained without failure. If the fluid overpressure develops in the whole model, the effective differential and mean stress approach zero and the vertical and horizontal effective principal stresses flip in orientation. The resulting fractures develop under high lithostatic fluid overpressure and are aligned semihorizontally, and consequently, a hydraulic breccia forms. If the area of high fluid pressure buildup is confined in a vertical zone, the effective mean stress decreases while the differential stress remains almost constant and failure takes place in extensional and shear modes at a much lower fluid overpressure. A horizontal fluid pressurized layer that is offset shows a complex system of effective stress evolution with the layer fracturing initially at the location of the offset followed by hydraulic breccia development within the layer. All simulations show a phase transition in the porosity where an initially random porosity reduces its symmetry and forms a static porosity wave with an internal dilating zone and the presence of dynamic porosity channels within this zone. Our results show that patterns of fractures, hence fluid release, that form due to high fluid overpressures can only be successfully predicted if the geometry of the geological system is known, including the fluid overpressure source and the position of seals and faults that offset source layers and seals.
CRIS-Team WoS Importer:2020-08-07

„Frankenalb-Malm“: Versenkungsgeschichte zur Kalibrierung eines Molassebecken-Aufschlußanalogs - Freitag, Simon; Drews, Michael; Bauer, Wolfgang; Stollhofen, Harald (DGMK Tagungsbericht 2018-1, 2018)
Mit der Suche nach alternativen Energieformen steigt auch wieder das Interesse an der Nutzung der tiefen Erdwärme. Mehrere Geothermie-Anlagen im Molassebecken sind bereits in Betrieb, wobei die meisten davon die geklüfteten Malm-Karbonate als Ziel-Reservoir angebohrt haben. Für ein verbessertes Systemverständnis dieses Reservoirs werden häufig Analog-Aufschlüsse auf der Fränkischen Alb herangezogen, da die im Molassebecken versenkten Karbonate hier an der Oberfläche austreten. Jedoch ist es bei der Verwendung von Reservoir-Analogen von großer Bedeutung, welche Versenkungsgeschichte die jeweiligen Gesteine erfahren haben, denn dies kann einen entscheidenden Einfluss auf die petrophysikalischen Eigenschaften der Aufschlussanaloge haben. Die Versenkungsgeschichte wurde für die Fränkische Alb bisher kaum untersucht. Ziel der vorliegenden Studie ist es die Versenkungsgeschichte mit Hilfe verschiedener Untersuchungsmethoden an den den Malm unterliegenden Dogger- und Lias-Tonen zu bestimmen. Dazu werden Methoden wie die Vitrinit-Reflexion sowie der Vergleich von Kompaktionstrends aus Bohrungen aus dem Bayerischen Molassebecken und Literaturdaten herangezogen. Verwendet werden dafür sowohl Tone, welche aus aktiven und stillgelegten Tongruben entnommen wurden, als auch Lias- und Dogger-Tone aus flachen Bohrungen. Erste Analysen der Gruben-Tone weisen bei einem Vergleich der Kompaktionstrends mit Bohrdaten aus dem Molassebecken eine Versenkungstiefe von ca. 500-1000 m auf. Diese Tiefenangabe ist jedoch erst eine grobe Einschätzung der tatsächlichen erfahrenen Versenkungstiefe, ein Abgleich mit den beschriebenen Messmethoden wird im nächsten Projektschritt durchgeführt.<br
Keywords: Fränkische Alb; Tonkompaktion; Versenkungsgeschichte

Frequency Ratio Analysis of Mass Movements in the Xiangxi Catchment, Three Gorges Reservoir Area, China - Ehret, Dominik; Rohn, Joachim; Dumperth, Christian; Eckstein, Susan; Ernstberger, Stefanie; Otte, Karel; Rudolph, Rene; Wiedenmann, Johannes; Wei, Xiang; Renneng, Bi (Journal of Earth Science, 2010)
In 2003, the Three Gorges Project (TGP, China), currently the world's largest hydroelectric power plant by total capacity, went into operation. Due to large-scale impoundment of the Yangtze River and its tributaries and also due to resettlement, extensive environmental impacts like land use change and increase of geohazards are associated with the TGP. Within the Yangtze Project, we investigate these effects for the Xiangxi (Chinese Source) catchment which is part of the Three Gorges Reservoir. The aim of this study is to evaluate the susceptibility for mass movement within the Xiangxi River backwater area using geographic information system (GIS). We used existing mass movements and the conditioning factors (geology, elevation, slope, curvature, land use, and land use change) for analyzing mass movement susceptibility. Mass movements and geology were mapped in the field to establish a mass movement inventory and a geological map. Land use and digital elevation model (DEM) were obtained from remote-sensing data. We determined the relation between mass movements and the conditioning factors by using the frequency ratio method and found strong relation between mass movements and both natural and human-influenced conditioning factors. © 2010 China University of Geosciences and Springer-Verlag Berlin Heidelberg.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.profes_3.freque
Keywords: frequency ratio; GIS; mass movement; Reservoir; susceptibility; Three Gorges; Xiangxi catchment

From Alpine-type sulfides to nonsulfides in the Gorno Zn project (Bergamo, Italy) - Mondillo, Nicola; Lupone, Federica; Boni, Maria; Joachimski, Michael; Balassone, Giuseppina; De Angelis, Marcello; Zanin, Simone; Granitzio, Fabio (Mineralium Deposita, 2020)
Keywords: Alpine-type; Exhumation; Gorno; C-O stable isotopes; Climate; Zn sulfides; Nonsulfides; Weathering

From arc accretion to continental collision in the eastern Jiangnan Orogen: Evidence from two phases of S-type granites - Wang, Xin-Shui; Gao, Jun; Klemd, Reiner; Jiang, Tuo; Zhai, Qing-Guo; Li, Ji-Lei; Liang, Xin-Quan (Precambrian Research, 2019)
The NE Jiangxi ophiolitic m lange separates the Huaiyu and Jiuling terranes in the eastern Jiangnan Orogen of the South China Block. Two phases of S-type granites, which are geochemically and mineralogically similar to the Himalayan leucogranites, are newly recognized in mantle peridotites of the NE Jiangxi ophiolite. The first phase, a tourmaline-bearing granite porphyry, has a SIMS zircon U-Pb age of 904.4 +/- 4.8 Ma and is strongly enriched in K2O (4.00-4.26 wt%) and strongly peraluminous (A/CNK = 2.94-3.24). It further shows high Rb/Sr ratios and highly fractionated REE patterns, indicating an origin due to fluid-absent melting of metapelites at relatively high temperatures. The granite porphyry exhibits highly evolved zircon Hf ( -6.0 to -1.0) and whole rock Nd ( -4.2 to -5.1) isotopes, which is in contrast to juvenile-derived magmatic rocks in the Huaiyu Terrane. We thus propose that the granite porphyry was formed by melting of the metapelites sourced from the Yangtze Block subsequent to the accretion of the Huaiyu arc to the Jiuling Terrane (the continental margin of the Yangtze Block). The second phase, a muscovite-bearing quartz porphyry, is strongly peraluminous (A/CNK = 1.29-1.34) with low CaO/Na2O ratios (0.11-0.14) and low FeOt + MgO + TiO2 contents (2.39-2.75 wt%), similar to melts derived from fluid-fluxed melting of metapelites. Zircon grains from the quartz porphyry yielded U-Pb ages of ca. 803-801 Ma with mainly positive epsilon(tif)(t) values ( + 1.9 to + 8.7), which are younger than the depositional ages of the basement sequences and nearly identical to the accumulation of the overlying unmetamorphosed cover in the Jiangnan Orogen. Therefore, it is suggested that the quartz porphyry was formed in a post-collisional extensional setting subsequent to the final assembly of the Yangtze and Cathaysia blocks. In conjunction with published data, we conclude that multiple subduction-accretion events may have been involved in the formation of the South China Block during Neoproterozoic times.
CRIS-Team WoS Importer:2019-02-21

From fossils to phylogenies: exploring the integration of paleontological data into Bayesian phylogenetic inference - Mulvey, Laura; Nikolic, Mark C.; Allen, Bethany J.; Heath, Tracy A.; Warnock, Rachel (Paleobiology, 2025)
Incorporating paleontological data into phylogenetic inference can greatly enrich our understanding of evolutionary relationships by providing insights into the diversity and morphological evolution of a clade over geological timescales. Phylogenetic analysis of fossil data has been significantly aided by the introduction of the fossilized birth-death (FBD) process, a model that accounts for fossil sampling through time. A decade on from the first implementation of the FBD model, we explore its use in more than 170 empirical studies, summarizing insights gained through its application. We identify a number of challenges in applying the model in practice: it requires a working knowledge of paleontological data and their complex properties, Bayesian phylogenetics, and the mechanics of evolutionary models. To address some of these difficulties, we provide an introduction to the Bayesian phylogenetic framework, discuss important aspects of paleontological data, and finally describe the assumptions of the models used in paleobiology. We also present a number of exemplar empirical studies that have used the FBD model in different ways. Through this review, we aim to provide clarity on how paleontological data can best be used in phylogenetic inference. We hope to encourage communication between model developers and empirical researchers, with the ultimate goal of developing models that better reflect the data we have and the processes that generated them.
CRIS-Team Scopus Importer:2025-05-09

From Global to Local and Vice Versa: On the Importance of the ‘Globalization’ Agenda in Continental Groundwater Research and Policy-Making - Filimonau, Viachaslau; Barth, Johannes (Environmental Management, 2016)

From loose sand to sandstone: An experimental approach on early calcite precipitation in sands of siliciclastic and mixed carbonate-siliciclastic composition - Janßen, Meike; Caracciolo, Luca; Bonnell, Linda M.; Lander, Robert H.; Adelhardt, Philipp; Moldenhauer, Lara; Munnecke, Axel; van Geldern, Robert; Stollhofen, Harald (PLoS ONE, 2024)
Artificially cemented sandstones were produced to assess the impact of detrital texture and composition on the precipitation and distribution of early calcite cement, and cement-related degradation in porosity. To simulate early-calcite cementation, loose sediment of variable composition (siliciclastic and calcareous) and grain size was exposed to a calcite supersaturated solution for 35 to 58 days at 23◦C. Identification and distribution of the newly precipitated crystals was performed with high resolution 2D optical and scanning electron microscopy. The experimental results show the precipitation of grain-coating, pore-bridging and pore-filling granular calcite cement with up to 100 μm crystal size. Despite a positive correlation between the amount of detrital carbonate grains and calcite crystals, calcite cement does not preferentially nucleate on bioclast surfaces, irrespectively of their favourable mineralogy. Siliciclastic grains show high calcite cement coverage with altered feldspar, particularly plagioclase, displaying coverage of 94.3%. Grain size variations within the sand packs have influence on the precipitation pattern of calcite with coarse-grained layers (500–710 μm) showing minor calcite cementation (6.3%), while medium- (250–500 μm) to fine-grained layers (125–250 μm) comprise average calcite cement contents of 16.3% and 28.2%, respectively. The findings of this study enhance our knowledge regarding the precipitation processes of calcite in porous material with heterogeneous reacting mineral phases, shapes and pore connectivity.
CRIS-Team Scopus Importer:2024-11-08

From patterns to processes: The future of reef research - Kießling, Wolfgang; Flügel, Erik; Golonka, Jan (Phanerozoic reef patterns, 2002)
UnivIS-Import:2015-04-20:Pub.2002.nat.dgeo.IGM.LP.frompa

From phosphors to ceramic magnets. Stability, crystal chemistry and applications of Hexa-aluminates and Hexa-ferrites - Göbbels, Matthias (Geochimica Et Cosmochimica Acta, 2007)
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LM.fromph

Fuzzy seas - Kießling, Wolfgang (Geology, 2015)
UnivIS-Import:2015-07-08:Pub.2015.nat.dgeo.IGM.LP.fuzzys

Gaining insights from past reefs to inform understanding of coral reef response to global climate change - Pandolfi, John; Kießling, Wolfgang (Current Opinion in Environmental Sustainability, 2014)
Global climate change is feared to lead to the collapse of living coral reefs, whose component organisms can respond in but three ways: migration, adaptation, and extinction. Because ancient reefs have been exposed to multiple episodes of environmental change, the fossil record provides an important resource for understanding the range of responses of coral reefs to climate change. Reef development has been slowed or stopped repeatedly in the history of life during periods of climate change. Whilst current conditions might be beyond some of the environmental ranges experienced throughout much of earth's history, coral reefs have shown a remarkable resilience to past climate change. Their fate today lies in the interaction between climate change and local anthropogenic stressors that have devastated a large proportion of living reef ecosystems. © 2013 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LP.gainin

Garnet-bearing ultramafic rocks from the Erzgebirge, and their relation to other settings in the Bohemian Massif - Schmädicke, Esther; et al. (Contributions To Mineralogy and Petrology, 1997)

Garnet in cratonic and non-cratonic mantle and lower crustal xenoliths from southern Africa: Composition, water incorporation and geodynamic constraints - Schmädicke, Esther; Gose, Jürgen; Reinhardt, Juergen; Will, Thomas M.; Stalder, Roland (Precambrian Research, 2015)
Keywords: Rehoboth terrane; Water in garnet; Eclogite; Alkremite; Pyroxenite; Kaapvaal Craton

Garnet pyroxenite, eclogite and alkremite xenoliths from the off-craton Gibeon Kimberlite Field, Namibia: A window into the upper mantle of the Rehoboth Terrane - Schmädicke, Esther; Okrusch, M.; Rupprecht-Gutowski, P.; Will, T. M. (Precambrian Research, 2011)
Keywords: Alkremite; Garnet pyroxenite; Eclogite; Gibeon kimberlite; Geothermobarometry; Mantle xenolith

Garnet pyroxenite from the Shackleton Range, Antarctica: Intrusion of plume-derived picritic melts in the continental lithosphere during Rodinia breakup? - Schmädicke, Esther; Will, Thomas M.; Mezger, Klaus (Lithos, 2015)
Keywords: Eclogite-facies garnet pyroxenite; Antarctica; Plume magmatism; Picrite; Shackleton range; Rodinia breakup

Gas-phase photocatalytic oxidation of dichlorobutenes - Barth, Johannes; et al. (Environmental Science & Technology, 2001)

Gastropoda - Seuß, Barbara; Nützel, Alexander (IGCP 596 Climate Change and Biodiversity Patterns in the Mid-Palaeozoic, 2016)

Gastropods from the Early/Middle Jurassic transition of Franconia (Southern Germany). - Schulbert, Christian; Nützel, Alexander (Bulletin of Geosciences, 2013)
A rich gastropod fauna is decribed from the Early/Middle Jurassic boundary (late Toarcian/early Aalenian) of Franconia (N Bavaria, South Germany). It comprises 35 nominate species and additional 9 species are treated in open nomenclature. With a few exceptions, the studied material comes from the Jurensismergel and the Opalinuston formations of the Mistelgau clay pit near Bayreuth. These sediments represent marine soft bottom environments. Gastropods are the most diverse and the most abundant group of the benthic communities in the Mistelgau clay pit. Bivalves, ophiurid and crinoid ossicles as well as foraminifera are also abundant. Among the bivalves, the paper pecten Bositra buchi and the inoceramid Pseudomytiloides dubium are especially abundant. Most of the members of the benthic fauna are small (< 15 mm) or even minute. Only the bivalve Pseudomytiloides dubium, some of the vetigastropods (e.g., Pleurotomarioidea) and the family Gordenellidae (Turritelloidea and Proacirsa) attain a size larger than 2 cm. However, these large species are rare. The most abundant gastropods are the caenogastropod species Coelodiscus minutus and Toarctocera subpunctata. Both species are especially abundant in the lowermost portions of the sampled section. Towards the Aalenian, an increase in diversity can be observed. This reflects recovery from the late Pliensbachian/early Toarcian extinction event. This event was connected with early Toarcian anoxia in Central and Northern Europe including black shale deposition (Posidonienschiefer). The studied gastropod fauna lived during still impoverished but improving environmental conditions. The relatively high diversity and abundance of the benthos suggest aerobic or dysaerobic conditions, however with possible fluctuations of oxygen concentrations. The fauna was also constrained by soft bottom conditions. 12 species are described as new: Mistelgauia monarii, Hummelgauia microstriata, Jurilda zapfi Schulbert, Nützel & Gründel sp. nov., Franconicilda juliae, Carinathilda? dieneri, Conusella convexa, Cossmannina eggmaieri, Sinuarbullina? mistelgauensis, Striactaeonina waltschewi Schulbert, Nützel & Gründel sp. nov., Striactaeonina richterorum Schulbert, Nützel & Gründel sp. nov., Parvulactaeon imprimum Schulbert, Nützel & Gründel sp. nov. and Parvulactaeon inclinatum Schulbert, Nützel & Gründel sp. nov. Three genera are described as new: Hummelgauia, Mistelgauia and Franconicilda. The family Coelodiscidae Gründel&Nützel fam. nov. is described as new based on the probably holoplanktonic gastropod genus Coelodiscus.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LP.gastro
Keywords: Aalenian; Gastropoda; Germany; Jurassic; Toarcian

Generalized Pan-European Geological Database for Shallow Geothermal Installations - Müller, Johannes; Galgaro, Antonio; Dalla Santa, Giorgia; Cultrera, Matteo; Karytsas, Constantine; Mendrinos, Dimitrios; Pera, Sebastian; Perego, Rodolfo; O'Neill, Nick; Pasquali, Riccardo; Vercruysse, Jacques; Rossi, Leonardo; et al. (Geosciences, 2018)

Generation and evolution of magma beneath the East Pacific Rise: Constraints from U-series disequilibrium and plagioclase-hosted melt inclusions - Zhang, Guo-Liang; Zeng, Zhi-Gang; Beier, Christoph; Yin, Xue-Bo; Turner, Simon (Journal of Volcanology and Geothermal Research, 2010)
Mid-ocean ridge basalt (MORB) samples from the East Pacific Rise (EPR 12°50'N) were analyzed for U-series isotopes and compositions of plagioclase-hosted melt inclusions. The Ra and Th excesses are negatively correlated; the Ra excess is positively correlated with Mg# and Sm/Nd, and is negatively correlated with La/Sm and Fe; the Th excess is positively correlated with Fe and La/Sm and is negatively correlated with Mg# and Sm/Nd. Interpretation of these correlations is critical for understanding the magmatic process. There are two models (the dynamic model and the "two-porosity" model) for interpreting these correlations, however, some crucial parameters used in these models are not ascertained. We propose instead a model to explain the U-series isotopic compositions based on the control of melt density variation. For melting either peridotite or the "marble-cake" mantle, the FeO content, Th excess and La/Sm ratio increases and Sm/Nd decreases with increasing pressure. A deep melt will evolve to a higher density and lower Mg# than a shallow melt, the former corresponds to a long residence time, which lowers the Ra excess significantly. This model is supported by the existence of low Ra excesses and high Th excesses in MORBs having a high Fe content and high density. The positive correlation of Ra excess and magma liquidus temperature implies that the shallow melt is cooled less than the deep melt due to its low density and short residence time. The correlations among Fe, Ti and Ca/Al in plagioclase-hosted melt inclusions further prove that MORBs are formed from melts having a negative correlation in melting depths and degrees. The negative correlation of Ra excess vs. chemical diversity index (standard deviation of Fe, Ti and Ca/Al) of the melt inclusions is in accordance with the influence of a density-controlled magma residence time. We conclude that the magma density variation exerts significant control on residence time and U-series isotopic compositions. © 2010 Elsevier B.V.
Keywords: East Pacific Rise; Magma density; Melt inclusion; Mid-ocean ridge basalt; U-series disequilibrium

Genesis of microbialites as contemporaneous framework components of deglacial coral reefs, Tahiti (IODP 310) - Westphal, Hildegard; Heindel, Katrin; Brandano, Marco; Peckmann, Joern (Facies, 2010)
Keywords: IODP 310; Microbialites; Nutrients; Reef development; Tahiti

Genesis of the Florida Canyon Nonsulfide Zn Ores (Northern Peru): New Insights Into the Supergene Mineralizing Events of the Bongará District - Chirico, Rita; Mondillo, Nicola; Boni, Maria; Joachimski, Michael; Ambrosino, Maurizio; Buret, Yannick; Mormone, Angela; Nazareno Beteta Leigh, Luis Enrique; Flores, Willy Huaman; Balassone, Giuseppina (Economic Geology, 2022)
The Florida Canyon Zn deposit in the Bongará Province of northern Peru consists of sulfide and nonsulfide mineralizations within dolomitized strata of the Triassic Chambará Formation, a member of the Triassic-Jurassic Pucará Group. The nonsulfide mineralization, which represents one third of the total resource, formed by supergene alteration of Mississippi Valley-type sulfide bodies. The nonsulfide assemblages occur in stratabound or fault-related, discordant zones that mimic the shapes of the former sulfide zones. Two nonsulfide facies can be distinguished: facies 1 – red zinc ores, which are characterized by smithsonite, or hemimorphite-dominant bodies that formed by direct replacement of primary sulfide assemblages, and facies 2 – white zinc ores, which are characterized by masses of colloform smithsonite formed by replacement of wall rock. The facies are distinct in bulk chemical composition and stable isotope geochemistry. Facies 1 shows high concentrations of Zn, Pb, Fe, Ge, Mn, and As, whereas facies 2 shows only high Zn and Cd concentrations. Enrichments in Ge, which have been reported in other Zn deposits of the Bongará Province, are associated with hemimorphite, Fe hydroxides, and remnant sphalerite in facies 1. The δ13C and δ18O signatures of smithsonite in both facies suggest that meteoric waters infiltrating the precursor sulfide bodies were affected by kinetic fractionation and originated from multiple sources at different altitude.

Genetically and geochronologically contrasting plagiogranites in Sotu Central Tianshan ophiolitic melanges: Implications fort he breakup of Rodinia and subduction zone processes - Jiang, Tuo; Gao, Jun; Klemd, Reiner; Qian, Qing; Zhang, Xi; Wang, Xinshui; Tan, Zhou; Zhu, Zhixin (Journal of Asian Earth Sciences, 2014)
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.c3geoc.geneti

Genetically and geochronologically contrasting plagiogranites in South Central Tianshan ophiolitic mélange: Implications for the breakup of Rodinia and subduction zone processes - Jiang, Tuo; Gao, Jun; Klemd, Reiner; Qian, Qing; Zhang, Xi; Wang, Xin-Shui; Tan, Zhou; Zhu, Zhixin (Journal of Asian Earth Sciences, 2015)
Plagiogranites are exposed as exotic blocks at two localities (Wuwamen and Guluogou) in the South Central Tianshan ophiolitic mélange and have U–Pb zircon ages of 775 ± 11 Ma and 416 ± 4 Ma, respectively. The Wuwamen plagiogranites have low-K tholeiitic to medium-K calc-alkaline and weakly peraluminous compositions. They further display relatively low concentrations of total rare earth elements (REEs), pronounced positive Eu anomalies and distinct depletions of P and Ti. The trace element characteristics, whole-rock initial 87Sr/86Sr ratios from 0.708812 to 0.708839 and negative εNd(t) values from −6.4 to −6.2 suggest that the granitic magma was derived from low degree partial melting of amphibolites at middle to lower crustal levels with hornblende as the dominant residual phase. In contrast, the Guluogou plagiogranites are strongly peraluminous and are characterized by an enrichment of both large ion lithophile elements (LILEs) and light rare earth elements (LREEs). Negative anomalies of Nb, Ta, P and Ti are in accordance with the geochemical signature of Andean arc-type granites. The zircon εHf(t) values from −6.1 to +2.4, the corresponding two-stage Hf model ages (TDMC = 1259–1798 Ma) and the εNd(t) values from −5.0 to −2.9 favor partial melting of ancient continental crust, which was contaminated by some juvenile material from a depleted-mantle wedge, for the origin of the Guluogou plagiogranites. Thus, we conclude that the Wuwamen and Guluogou plagiogranites have no direct genetic relationship with the ophiolites and occur as exotic blocks in the ophiolitic mélanges. It is further suggested that the 775 Ma Wuwamen plagiogranites originated during the breakup of Rodinia, whereas the 416 Ma Guluogou plagiogranites were generated in an Andean-type active continental margin environment related to the northward subduction of the South Tianshan Ocean.<br
Keywords: Geochemistry; Geochronology; Plagiogranite; South Central Tianshan ophiolitic mélange; Subduction; Rodinia

Genome-wide transcriptomic analysis of response to low temperature reveals candidate genes determining divergent cold-sensitivity of maize inbred lines - Sobkowiak, Alicja; Jończyk, Maciej; Jarochowska, Emilia; Biecek, Przemyslaw; Trzcinska-Danielewicz, Joanna; Leipner, Jörg; Fronk, Jan; Sowinski, Pawel (Plant Molecular Biology, 2014)
Keywords: Gene ontology; Low temperature; qRT PCR; QTL; Transcriptomics; Zea mays

Geo-biology of Mediterranean deep-water coral ecosystems - Taviani, Marco; Angeletti, Lorenzo; Antolini, Bruno; Ceregato, Alessandro; Froglia, Carlo; López Correa, Matthias; Montagna, Paolo; Remia, Alessandro; Trincardi, Fabio; Vertino, Agostina (Marine Research at CNR, 2011)
Cold (or deep) water corals (CWC) are a spectacular and widespread component of the ocean biota. Highly structured CWC ecosystems serve as biodiversity hotspots suggesting the need for the proper management of these unique habitats. Among the most relevant actors in promoting the growth of conspicuous structures (deep water reefs and mounds) are branching stony corals like Lophelia pertusa and Madrepora oculata. These widespread frame-builders occur also in the Mediterranean basin and are the backbone of Recent CWC provinces identified thus far in the Ionian Sea (Santa Maria di Leuca), South Adriatic Sea, Strait of Sicily, Catalan-Provenc¸al canyons and Alboran Sea. CWC seem strongly influenced by oceanographic factors coupled with proper substrata, such as steep (canyon heads, seamount walls etc) or rugged (slumped blocks) topographies. Dead pre-Modern coral assemblages are present in the entire Sea. These submerged fossil assemblages have been mostly U/Th and 14C dated at the latest Pleistocene documenting propitious basin-wide conditions for their successful growth during glacial periods.
UnivIS-Import:2015-04-20:Pub.2011.nat.dgeo.IGM.LP.geobio
Keywords: cold-water corals

Geochemical and geochronological constraints on the evolution of the Azores Plateau - Beier, Christoph; Haase, Karsten; Abouchami, Wafa (Geological Society of America, 2015)
We report new 40Ar/39Ar ages on submarine lavas from the Azores Plateau that yield ages of 6-4.9 Ma and 1.5 Ma to Holocene. An additional sample from the eastern plateau gives an age of 39 Ma. Thus, at least two, possibly even three eruptive phases occurred in the past 39 m.y. The lava compositions range from slightly incompatible trace element-enriched tholeiites to highly enriched alkali basalts similar to those erupted on the Azores islands. The less enriched tholeiitic lavas occur in the westernmost plateau and formed by relatively high degrees of partial melting. The highly enriched alkali basalts appear to be restricted to local volcanic structures, implying different phases of intraplate volcanism that are possibly related to the jump of the ultraslow-spreading Terceira Rift within the Azores Plateau. The abundance and widespread spatial distribution of volcanism with ages of 6-4.9 Ma in subaerial and submarine lavas implies the presence of a thermal or chemical melting anomaly and a period of enhanced volcanism that led to tholeiitic volcanism following, and being followed by, alkali-basaltic volcanism. The small-scale (Sr. )Nd-Pb isotopic heterogeneity of the Azores plume source implies limited mixing in the mantle, in contrast to observations made on other plume-related settings such as the Galapagos. We suggest that the Azores Plateau initially formed from interaction between geochemically and thermally anomalous mantle, possibly a small mantle plume, arriving underneath the lithosphere, and the local plate tectonics, i.e., the Terceira Rift axis, provided ascent paths for the generated magmas.

Geochemical and geochronological evidence for a former early Neoproterozoic microcontinent in the South Beishan Orogenic Belt, southernmost Central Asian Orogenic Belt - Yuan, Yu; Zong, Keqing; He, Zhenyu; Klemd, Reiner; Liu, Yongsheng; Hu, Zhaochu; Guo, Jingliang; Zhang, Zeming (Precambrian Research, 2015)
The South Beishan Orogenic Belt (SBOB) in the southwestern Central Asian Orogenic Belt (CAOB) is thought to be an eastern extension of the Eastern Tianshan Orogen. Up to now, it has been suggested to consist of a well-preserved Paleozoic magmatic and sedimentary sequence with a possible former Neoproterozoic microcontinent. We provide new geochemical and geochronological data for gneissic granites of the SBOB in order to constrain its tectonic evolution and setting. The gneissic granitoids belong to the high-K, calc-alkaline series and are characterized by an enrichment of light rare earth elements (LREE) and large ion lithophile elements (LILE), a depletion of Nb, Ta, Ti, Sr, and Ba and a positive Pb anomaly. The petrography and geochemical signatures reveal a possible I-type granite affinity and are in accordance with typical Andean Arc granites. Zircon grains, yielding 206Pb/238U magmatic crystallization ages of 933 ± 2 Ma and 900–890 Ma for the Shibanshan and Huaniushan arc granites, respectively, manifest the former presence of an early Neoproterozoic Precambrian microcontinent in the SBOB. Zircon ɛHf(t) values range from −16.1 to 10.2, indicating that juvenile material and reworked ancient crust were involved in the source of the gneissic granites. Furthermore, in conjunction with studies of the adjacent regions, the results of the present study suggest that the former Precambrian microcontinent in the SBOB neither belonged to the nearby Dunhuang Block nor the Tarim Craton, but has a common affinity with the Central Tianshan Arc Terrane. It is also suggested that the 900–890 Ma plutons originated from the mixing of juvenile material with older crust in an Andean-type active continental arc setting during the assembly of Rodinia. Thus the SBOB plays a key role in understanding the tectonic evolution of the CAOB.
Keywords: South Beishan Orogenic Belt (SBOB); Central Asian Orogenic Belt (CAOB); Neoproterozoic microcontinent; Zircon U-Pb dating; Assembly of Rodinia

Geochemical and geochronological studies of granitoid rocks from the Western Tianshan Orogen: Implications for continental growth in the southwestern Central Asian Orogenic Belt. - Long, Lingli; Gao, Jun; Klemd, Reiner; Beier, Christoph; Qian, Qing; Zhang, Xi; Wang, Jingbin; Jiang, Tuo (Lithos, 2011)
The Western Tianshan Orogen in northwestern China is part of the southwestern margin of the Central Asian Orogenic Belt (CAOB), which represents the largest tectonic assembly of accretionary complexes and the most significant area of Phanerozoic continental growth in the world. Granitoid rocks have a widespread occurrence and occupy about 30% of the whole exposure of the orogen. Ages obtained for the granitoids vary from 896Ma to 247Ma, while initial 87Sr/86Sr ratios vary from 0.70329 to 0.72070 and εNd values from -14.1 to +7.3. The occurrence of Neoproterozoic granitic gneisses implies the presence of Precambrian basement in this area. During oceanic subduction, continental growth occurred as a result of several combined processes, i.e. by addition of oceanic crustal melts (adakites), the intrusion of basaltic magmas derived by partial melting of the metasomatized depleted mantle wedge and the upwelling of granitic magma derived from a mixed source of basaltic magmas and old continental basement. However, during the post-collisional period, vertical accretion of underplated juvenile mantle material may have been accomplished during 'slab breakoff' delamination. This study suggests a two stage model of continental growth of 'syn-subduction lateral accretion of arc complexes' and 'post-collisional vertical accretion of underplated mantle material', which may also be relevant for the western segment of the CAOB in the Phanerozoic. The reworking and involvement of old crust are more obvious in the Western Tianshan Orogen compared to other parts of the CAOB comprising the Western Junggar, Eastern Junggar, Alataw and Altay terranes. © 2011 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.c3geoc.geoche
Keywords: Continental growth; Granitoid rocks; Sr-Nd isotope; Tianshan; Zircon U-Pb age

Geochemical and isotope characterization of geothermal spring waters in Sri Lanka: Evidence for steeper than expected geothermal gradients - Chandrajith, Rohana; Barth, Johannes; Subasinghe, N. D.; Merten, Dirk; Dissanayake, C. B. (Journal of Hydrology, 2013)

Geochemical and isotope characterization of groundwater and assessment of surface water mixing in the coastal karst aquifer basin in northwestern Sri Lanka - Bandara, U. G. Chaminda; Diyabalanage, Saranga; Barth, Johannes; Chandrajith, Rohana (Applied Geochemistry, 2024)
Sinkholes play a critical role in groundwater systems by facilitating both recharge and discharge of groundwater, serving as indicators of underlying geologic processes, shaping subsurface hydrology, and influencing water quality. Therefore, studying karst groundwater systems is essential for effective groundwater management, especially in areas with limestone sequences. Spatial variations of water isotopes (δ2H, δ18O), dissolved inorganic and organic carbon (DIC and DOC), including their isotopes alone with pH, EC, alkalinity and chloride were determined in surface- and groundwater of the Mulankavil karst aquifer basin in the northwest of Sri Lanka. Twenty-seven groundwater wells, one offshore spring and two sinkholes were selected for sampling. The contribution of sinkhole water and seawater to karst aquifers was calculated using δ18O and chloride as tracers. In addition, deuterium excess (d-excess) values were used to determine groundwater evaporative loss before infiltration. Near the Mulankavil sinkhole area, the mixing of surface water and infiltrating rainwater was found to vary between 26 and 60%, with an average of 56%. In contrast, surface water mixing in the Nagapadduvan and Vellankulam sinkholes was about 41–59% and 33–70%, respectively. In near coastal wells, these values fell to 20% due to the influence of seawater intrusion. During the dry season, groundwater d-excess varied between −5.0 and + 10.8‰, while surface water in sinkholes showed values between +1.8 and −9.4‰. Groundwater wells near the Mulankavil sinkhole showed lower DIC (<5.5 mmol/L) with enriched δ13CDIC (>-14‰). The karst aquifer systems in northern Sri Lanka exhibit two main recharge mechanisms: (a) selective recharge by surface water at sinkholes and (b) diffuse recharge by direct rainfall over the study area. Seawater intrusion near the coast can be prevented by artificially recharging rainwater during the monsoon season.
CRIS-Team Scopus Importer:2024-07-19
Keywords: Dissolved inorganic carbon; Dissolved organic carbon; Groundwater quality; Karst basins; Mixing models; Mulankavil; Stable carbon isotopes

Geochemical and isotopic constraints on the tectonic and crustal evolution of the Shackleton Range, East Antarctica, and correlation with other Gondwana crustal segments - Will, T. M.; Frimmel, H. E.; Zeh, A.; Le Roux, Petrus; Schmädicke, Esther (Precambrian Research, 2010)
Keywords: Zircon single grain Lu-Hf isotopes; East Antarctica; Crustal evolution and sutures; Shackleton Range; Lithogeochemistry; Whole rock Rb-Sr; Sm-Nd and Pb-Pb isotopes

Geochemical anomalies caused by meteorite impact and volcanism at the Cretaceous-Paleogene boundary, Wasserfallgraben (Lattengebirge, Germany) - Regelous, Anette; Ćorić, Stjepan; Regelous, Marcel; Teipel, Ulrich (Cretaceous Research, 2022)
The Cretaceous-Paleogene (K/Pg) mass extinction is the only major mass extinction event that is known to be related to a major meteorite impact (Chicxulub, Mexico) and also occurred during major flood basalt eruptions (Deccan Traps, India). Here, we present geochemical proxies for impact and volcanism analysed in the same sediment samples from the deep-marine sedimentary record of the Gosau Group spanning the K/Pg boundary at Wasserfallgraben, Germany. We measured major and trace elements, including iridium (Ir), tellurium (Te), mercury (Hg), total organic carbon (TOC), and organic carbon isotopes (δ13Corg) on 33 samples from 2 m below to 1.36 m above the K/Pg boundary, a timespan of ∼260 ka. Results show an undisturbed profile, confirmed by changes in calcareous nannofossils assemblages, with a sharp positive Ir peak (2.3 ppb) at the K/Pg boundary (0–10 cm, 25 cm). Volcanic proxies (Hg/TOC, Te/Th) show three distinct peaks not corresponding to the Ir peak, suggesting a volcanic origin, and higher values in the earliest Danian. Compared to the profile in Bidart the proxies of volcanism are less intense in our profile, indicating that the “Deccan Signal” is either diluted or not present in some locations worldwide. The time recorded in the sampled sediments is short (∼0.26 Ma) compared to Deccan flood basalt eruptions (∼1 Ma), but elevated Hg/TOC and Te/Th ratios in the Danian sediments suggests the impact happened prior to the main volcanic outgassing of the Deccan Traps. Our results support the hypothesis that the impact might have triggered the largest, rapidly-erupted Deccan lava formations.
CRIS-Team Scopus Importer:2022-10-07
Keywords: Cretaceous/Paleogene boundary; Iridium; Mass extinction; Mercury; Wasserfallgraben

Geochemical Characteristics of Groundwater Consumed by Patients with Chronic Kidney Disease with Unknown Aetiology in the Crystalline Dry Zone Terrain of Sri Lanka - Chandrajith, Rohana; Nanayakkara, Nishantha; Zwiener, Christian; Daniel, Christoph; Amann, Kerstin Ute; Barth, Johannes (Exposure and Health, 2023)
Quality of drinking water has become a significant concern with chronic kidney disease of uncertain aetiology (CKDu), particularly in the dry zone regions of Sri Lanka. In this study, groundwaters consumed by biopsy-proven CKDu patients were assessed for identifying possible hydrogeochemical risk factors because histopathological observations are still considered the best method for identifying CKDu cases. Major anions, cations, and 22 trace elements in groundwater were measured in addition to dissolved organic carbon (DOC) and its isotope ratios (expressed as δ13CDOC). Variations of groundwater quality were monitored monthly in five selected wells. The data were compared with a non-endemic region with a similar climatic and socio-economic background. Groundwater used by CKDu cases is predominantly of the Ca–Mg–HCO3 type. Over 88% of the samples showed excess hardness, while 44% showed high fluoride (F−) contents (> 0.60 mg/L). These two parameters are noticeably different compared to groundwater from non-endemic regions with similar geoenvironmental backgrounds. The dissolved organic carbon (DOC) content varied from 0.06 to 0.30 mmol/L with a mean value of 0.15 mmol/L in CKDu wells. In most cases, known nephrotoxic trace elements such as As, Pb, Cd, and U were found to be lower than 0.01 µg/L. Seasonally, F− and Si4+ (as H4SiO4) content fluctuated, even though monsoon rain inputs did not seem to alter the geochemical composition. Principal component analysis (PCA) indicated that the dissolution of aquifer minerals and ion exchange processes are most likely responsible for the groundwater geochemistry in the study terrain. This study highlights the importance of F−, hardness (Ca2+ + Mg2+), and Si4+ in groundwaters of CKDu-related tropical terrains. The synergetic impact of these parameters needs further systematic studies, ideally combined with animal models, to unravel the aetiological mechanisms of CKDu.
CRIS-Team Scopus Importer:2023-04-14
Keywords: CKDu; Dissolved organic carbon; Environmental-nephrotoxin; Fluoride; Silica; Water hardness; Water isotopes

Geochemical constraints on magma sources and mixing processes in Easter Microplate MORB (SE Pacific): A case study of plume-ridge interaction. - Haase, Karsten (Chemical Geology, 2002)
The Easter Microplate is bounded in the east and west by two large overlapping spreading centres called the East and West Rift, respectively. The East Rift is located close to the Easter Hotspot, the site of young intraplate volcanism above a mantle plume. Easter Hotspot material creates a geochemical anomaly on the East Rift spreading axis of the microplate and mainly northward-directed material flow occurs beneath the propgating East Rift. The incompatible element-depleted mantle of the Easter Microplate consists of two different sources, one of which mixes with enriched Easter Hotspot material forming the East Rift Mid-ocean ridge basalt (MORB). The other depleted mantle source is present beneath the West Rift and mixes with an enriched endmember apparently distinct from the Easter Hotspot source. While the Easter Hotspot material leads to a bathymetric anomaly on the East Rift, no increased degree of melting is observed at the point of maximum inflow of enriched plume material, implying low excess temperatures (< 50°C) of the mantle. The mixing processes between the Easter Hotspot and MORB material probably take place in the partially molten asthenosphere during the horizontal flow of the plume material. Melting above the plume and at the spreading axes in the Easter Microplate region occurs over a range of pressures but there is no sign of melts from enriched garnet pyroxenite. © 2002 Elsevier Science B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.legeo.geoche_9
Keywords: Isotopes; Mantle plume; Mid-ocean ridge basalt; Plume-ridge interaction; Trace elements

Geochemical constraints on the link between volcanism and plutonism at the Yunshan caldera complex, SE China - Yan, Lili; He, Zhenyu; Beier, Christoph; Klemd, Reiner (Contributions To Mineralogy and Petrology, 2018)
Keywords: Crystal mush; Magma differentiation; Peralkaline rhyolite; Quartz monzonite; Yunshan caldera complex; Zircon Hf–O isotopes

Geochemical evidence for major environmental change at the Devonian-Carboniferous boundary in the Carnic Alps and the Rhenish Massif - Kaiser, Sandra; Steuber, Thomas; Becker, R. T.; Joachimski, Michael (Palaeogeography, Palaeoclimatology, Palaeoecology, 2006)
Keywords: Apatite; C isotopes; Conodonts; Devonian-Carboniferous boundary; Mass extinction event; O isotopes

Geochemical evidence for major environmental change at the Devonian-Carboniferous boundary mass-extinction. - Joachimski, Michael; et al. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2006)
UnivIS-Import:2015-03-09:Pub.2006.nat.dgeo.IGM.LG.geoche

Geochemical evidence for melting of carbonated peridotite on Santa Maria Island, Azores - Beier, Christoph; Mata, Joao; Stoeckhert, Ferdinand; Mattielli, Nadine; Brandl, Philipp; Madureira, Pedro; Genske, Felix; Martins, Sofia; Madeira, Jose; Haase, Karsten (Contributions To Mineralogy and Petrology, 2013)
The islands of the Azores archipelago emerge from an oceanic plateau built on lithosphere increasing in age with distance from the Mid-Atlantic Ridge from 10 to 45 Ma. Here, we present the first comprehensive major and trace element and Sr-Nd-Pb isotope data from Santa Maria, the easternmost island of the archipelago, along with published data from the other Azores islands situated much closer to the Mid-Atlantic Ridge axis. We can show that the distinctively more variable and more enriched trace element ratios at Santa Maria combined with a relatively small range in Sr-Nd-Pb isotope ratios are the result of low degrees of partial melting of a common Azores mantle plume source underneath thicker lithosphere. This implies that melt extraction processes and melting dynamics may be able to better preserve the trace element mantle source variability underneath thicker lithosphere. These conclusions may apply widely for oceanic melts erupted on relatively thick lithosphere. In addition, lower Ti/Sm and K/La ratios and SiO contents of Santa Maria lavas imply melting of a carbonated peridotite source. Mixing of variable portions of deep small-degree carbonated peridotite melts and shallow volatile-free garnet peridotite could explain the geochemical variability underneath Santa Maria in agreement with the volatile-rich nature of the Azores mantle source. However, Santa Maria is the Azores island where the CO-rich nature of the mantle source is more evident, reflecting a combination of a smaller extent of partial melting and the positioning at the edge of the tilted Azores mantle plume. © 2012 Springer-Verlag Berlin Heidelberg.
Keywords: Azores; Carbonated peridotite; Lithosphere thickness; Melting dynamics; Ocean Island Basalts

Geochemical evidence for Paleozoic crustal growth and tectonic conversion in the Northern Beishan Orogenic Belt, southern Central Asian Orogenic Belt - Yuan, Yu; Zong, Keqing; He, Zhenyu; Klemd, Reiner; Jiang, Hongying; Zhang, Wen; Liu, Yongsheng; Hu, Zhaochu; Zhang, Zeming (Lithos, 2018)
The Beishan Orogenic Belt is located in the central southernmost part of the Central Asian Orogenic Belt (CAOB), which plays a key role in understanding the formation and evolution of the CAOB. Granitoids are the documents of crustal and tectonic evolution in orogenic belts. However, little is known regarding the petrogenesis and geodynamic setting of the widely distributed Paleozoic granitoids in the Northern Beishan Orogenic Belt (NBOB). The present study reveals significant differences concerning the petrogenesis and tectonic setting of early and late Paleozoic granitoids from the NBOB. The early Paleozoic granitoids from the 446–430 Ma Hongliuxia granite complex of the Mazongshan unit and the 466–428 Ma Shibanjing complex of the Hanshan unit show classic I-type granite affinities as revealed by the relative enrichment of LILEs and LREEs, pronounced depletions of Nb, Ta and Ti and the abundant presence of hornblende. Furthermore, they are characterized by strongly variable zirconεHf(t) values between − 16.7 and + 12.8 and evolved plagioclase Sr isotopic compositions of 0.7145–0.7253, indicating the involvement of both juvenileand ancient continental crust in the magma source. Thus, we propose that the early Paleozoic granitoids in the NBOB were generated in a subduction-related continental arc setting. In contrast, the late Paleozoic 330–281 Ma granitoids from the Shuangjingzi complex of the Hanshan unit exhibit positive zircon εHf(t) values between + 5.8 and + 13.2 and relatively depleted plagioclase Sr isotopic compositions of 0.7037–0.7072, indicating that they were mainly formed by remelting of juvenile crust. Thus, an intra-plate extensional setting is proposed to have occurred during formation of the late Paleozoic granitoids. Therefore, between the early and late Paleozoic, the magma sources of the NBOB granitoids converted from the reworking of both juvenile and ancient crusts during a subduction-induced compressional setting to the remelting of juvenile crust during an intra-plate extensional setting, respectively. The corresponding crustal growth in the southern CAOB is dominated by early Paleozoic lateral accretion of arc complexes and late Paleozoic vertical addition of juvenile material from the mantle.
Keywords: Paleozoic granitoids; Crustal growth; Tectonic conversion; Northern Beishan Orogenic Belt; Central Asian Orogenic Belt (CAOB)

Geochemical mapping of a paleo-subduction zone beneath the Troodos Ophiolite - Wölki, Dominic; Regelous, Marcel; Haase, Karsten; Beier, Christoph (Chemical Geology, 2019)
Supra-subduction zone ophiolites such as the Cretaceous Troodos Ophiolite of Cyprus are fragments of oceanic crust formed by seafloor spreading close to subduction zones. Their exact tectonic setting of origin has been intensively debated. Although many supra-subduction zone ophiolites are thought to represent fore-arc crust, created during subduction initiation, others may have formed at a subducting ridge, or in a back-arc, ridgetrench-trench/transform triple junction or ‘plate edge’ setting. We carried out major and trace element analyses of 515 fresh volcanic glasses from 7 detailed sections through the Troodos lava sequence in order to determine the regional and temporal variation in the composition of Troodos magmatism, and hence reconstruct the distance and orientation of the Troodos spreading axis relative to the former subduction zone. Troodos glasses range from boninite through tholeiitic basalt and andesite to dacite. All glasses are enriched in fluid-mobile trace elements, and variably depleted in the high-field strength elements compared to Mid-Ocean Ridge Basalt (MORB). None of these glasses therefore have compositions identical to Izu-Bonin-Mariana fore-arc lavas that have been proposed to be the prime example of lavas formed during subduction initiation. Boninites are apparently restricted to the southern margin of the Troodos Ophiolite, and glasses from the southeast margin of the ophiolite are the most depleted and contain the strongest input of subduction zone fluid and melt signature. These geographic variations in glass composition indicate that the Troodos Ophiolite formed by NW-SE directed spreading (at 91 Ma) approximately 100–120 km above an eastward-dipping subducting plate. The orientation of the Troodos spreading axis relative to the former trench could be explained if the Troodos Ophiolite formed in a fore-arc position by subduction initiation at a transform fault. However, the lack of glasses with fore-arc basalt composition, and similarities between the trace element compositions of Troodos glasses and those from the Fonualei basin and northern Lau Basin in the southwest Pacific suggest that the Troodos Ophiolite formed in a ridge-trench-trench or ridge-trench-transform triple junction setting, at a back-arc spreading centre that propagated into arc and fore-arc crus

Geochemische und fazielle Muster in peritidalen Kalk/Dolomit-Zyklen der oberen Bellerophon-Schichten (Oberperm) in den Südalpen. - Buggisch, Werner; Krumm, Stefan; Noe, Sibylle (Abhandlungen der Geologischen Bundesanstalt Wien, 1994)
UnivIS-Import:2015-03-05:Pub.1994.nat.dgeo.IGM.LG.geoche

Geochemistry and geochronology of a Precambrian high-grade metamorphic complex in an ophiolitic mélange of the Central Tianshan Arc Terrane, NW China - Wang, Xin-Shui; Gao, Jun; Klemd, Reiner; Jiang, Tuo; Li, Ji-Lei; Zhang, Xi; Tan, Zhou; Li, Le; Zhu, Zhixin (Precambrian Research, 2014)
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.c3geoc.geoche

Geochemistry and geochronology of the Precambrian high-grade metamorphic complex in the Southern Central Tianshan ophiolitic mélange, NW China - Wang, Xin-Shui; Gao, Jun; Klemd, Reiner; Jiang, Tuo; Li, Ji-Lei; Zhang, Xi; Tan, Zhou; Li, Le; Zhu, Zhixin (Precambrian Research, 2014)
The Central Tianshan Arc Terrane is one of the major constituents of the Tianshan orogen in the southwestern Altaids. Thus its Precambrian evolution is important for unravelling the geodynamic and continental evolution of the Altaids. Biotite-plagioclase-hornblende orthogneisses intruded by leucogranite dykes are exposed as exotic blocks within the Southern Central Tianshan ophiolitic mélange. Zircon U–Pb age dating of one orthogneiss sample yields an upper intercept age of 2466 ± 51 Ma and a weighted mean 207Pb/206Pb age of 1812 ± 19 Ma around the lower intercept. These ages are interpreted as protolith crystallization age and subsequent metamorphic overprint age, respectively. The orthogneisses have moderate SiO2 contents, high MgO and Na2O contents, high Sr/Y ratios (32–43) and moderately fractionated REE patterns ([La/Yb]N = 7.59–13.64) with negligible Eu anomalies, enriched Sr contents and pronounced negative Th–U, Nb–Ta, Zr–Hf and Ti anomalies resembling high-SiO2 TTGs derived from subducted basaltic slab-melts. Positive ɛHf(t) values (+3.4 to +9.2) and low (176Hf/177Hf)i ratios (0.281304–0.281469) with Neoarchaean to early Paleoproterozoic single-stage Hf model ages (TDM1 = 2431–2652 Ma) suggest that the orthogneisses probably originated from partial melting of juvenile subducted oceanic crust. The orthogneisses were subsequently also affected by collisional orogenic events associated with the assembly of the supercontinent Columbia. In contrast, the zircon U–Pb age of 785 ± 15 Ma obtained for the intrusive leucogranite dykes is consistent with the timing of rifting events associated with the breakup of Rodinia. The leucogranites have a high-Al trondhjemitic composition characterized by extremely low MgO and K2O contents as well as high SiO2, Al2O3 and Na2O contents, dramatically low ∑REE abundances and REE patterns with moderate LREE enrichments ([La/Yb]N = 3.55–8.4) and pronounced positive Eu anomalies (Eu/Eu* = 1.29–2.61). The high zircon initial Hf compositions (0.281670–0.281841) and negative ɛHf(t) values (−21.7 to −15.4), in conjunction with high whole-rock initial 87Sr/86Sr ratios (0.70737–0.70751) and negative ɛNd(t) values (−4.7 to −5.1) suggest that the leucogranite resulted from reworking of ancient lower crust. Based on the presented data we conclude that the Central Tianshan Arc Terrane has undergone three tectonothermal events, namely ∼2.5 Ga continental crustal growth, ∼1.8 Ga collision related to the Columbia assembly and ∼785 Ma crustal reworking due to the Rodinia breakup. The Central Tianshan Arc Terrane, which experienced the same tectonic events as the Tarim Craton during the Precambrian, is considered to be a micro-Precambrian block that separated from the Tarim Craton during the Rodinia breakup.
Keywords: Central Tianshan; Wuwamen Complex; Supercontinent; Tarim Craton; Tectonic evolution

Geochemistry and petrology of lavas from the submarine flanks of Réunion Island (western Indian Ocean): Implications for magma genesis and the mantle source. - Fretzdorff, Susanne; Haase, Karsten (Mineralogy and Petrology, 2002)
Major and trace element data as well as Sr and Nd isotope compositions for submarine lavas from the flanks of Réunion island are reported. The submarine basalts of the island have major and trace element compositions similar to those of the subaerial basaltic rocks. This implies that no compositional change occurs in the shield-building magmas of the two Réunion volcanoes. Fractional crystallization of lavas from both Piton de la Fournaise and Piton des Neiges begin well within the mantle at pressures up to 1 GPa which is significantly deeper than the crust-mantle boundary at about 12 km depth. The Réunion primary magmas form at an average depth of about 4 GPa in agreement with the thickness of the plate beneath the island. Lavas from both Réunion volcanoes have similar trace element compositions with the exception of lower Th/Ba for Piton des Neiges which implies a relatively homogeneous plume source during, at least, the last 2 Ma. The lack of any variation in the partial melting processes during this time span implies a thermal steady state of the plume centre. The Réunion lavas form either from a source that was enriched by partial melting or that contains recycled enriched MORB. Based on MORB- like Ce/Pb and Nb/U ratios an influence by fluid-metasomatized mantle, sediment or continental crustal material in the Réunion source appears unlikely.
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.legeo.geoche

Geochemistry of fluoride in the environment and human health - Chandrajith, Rohana; Dissanayake, C. B.; Barth, Johannes (wiley, 2023)
Fluoride is considered an essential element for dental health hence is added to many water supplies and toothpaste. On the other hand, high concentrations of fluoride in drinking water can also be detrimental to health. Dental (mottled enamel) and skeletal fluorosis are the most common health impacts that can occur due to drinking high fluoride water among many others. Fluoride enters the human body primarily from drinking water supplies. Groundwater, which is the main source of drinking water in tropical countries, encountered higher content of fluoride. The source of excess fluoride in groundwater is mostly geogenic in origin. Particularly in deep groundwater fluoride contents are higher due to longer contact time with fluoride-bearing minerals compared to shallow and surface waters. Content in fluoride in groundwater is primarily limited by the solubility of fluoride-bearing minerals, alkalinity of the solution, and presence of calcium. Water containing excess fluoride is colorless and tasteless, and chemical tests are required to detect its presence. The World Health Organization has set a recommended limit for fluoride in drinking water at 1.5 mg/L due to its potential detrimental health impacts but such limits are not acceptable for tropical countries.
CRIS-Team Scopus Importer:2024-12-16
Keywords: Dental and skeletal fluorosis; Fluoride in tea; Medical geology; Pineal gland; Tropical terrain

Geochemistry of serpentinized and multiphase altered Atlantis Massif peridotites (IODP Expedition 357): Petrogenesis and discrimination of melt-rock vs. fluid-rock processes - Whattam, Scott A.; Frueh-Green, Gretchen L.; Cannat, Mathilde; De Hoog, Jan C. M.; Schwarzenbach, Esther M.; Escartin, Javier; John, Barbara E.; Leybourne, Mathew; Williams, Morgan J.; Roumejon, Stephane; Akizawa, Norikatsu; Boschi, Chiara; et al. (Chemical Geology, 2022)
International Ocean Discovery Program (IODP) Expedition 357 drilled 17 shallow sites distributed similar to 10 km in the spreading direction (from west to east) across the Atlantis Massif oceanic core complex (Mid-Atlantic Ridge, 30 degrees N). Mantle exposed in the footwall of the Atlantis Massif oceanic core complex is predominantly nearly wholly serpentinized harzburgite with subordinate dunite. Altered peridotites are subdivided into three types: (I) serpentinites, (II) melt-impregnated serpentinites, and (III) metasomatic serpentinites. Type I serpentinites show no evidence of melt-impregnation or metasomatism apart from serpentinization and local oxidation. Type II serpentinites have been intruded by gabbroic melts and are distinguishable in some cases on the basis of macroscopic and microscopic observations, e.g., mm-cm scale mafic-melt veinlets, rare plagioclase (<0.5 modal % in one sample) or by the local presence of secondary (replacive) olivine after orthopyroxene; in other cases, 'cryptic' melt-impregnation is inferred on the basis of incompatible element enrichments. Type III serpentinites are characterized by silica metasomatism manifest by alteration of orthopyroxene to talc and amphibole, and by anomalously high anhydrous SiO2 concentrations (59-61 wt%) and low MgO/SiO2 values (0.48-0.52). Although many chondrite-normalized rare earth element (REE) and primitive mantle-normalized incompatible trace element anomalies, e.g., negative Ce-anomalies, are attributable to serpentinization, other compositional heterogeneities are due to melt-impregnation. On the basis of whole rock incompatible trace elements, a dominant mechanism of melt-impregnation is distinguished in the central and eastern serpentinites from fluid-rock alteration (mostly serpentinization) in the western serpentinites, with increasing melt-impregnation manifest as a west to east increase in enrichment in high-field strength elements and light REE. High degrees of melt extraction are evident in low whole-rock Al2O3/SiO2 values and low concentrations of Al2O3, CaO and incompatible elements. Estimates of the degree of melt extraction based on whole rock REE patterns suggest a maximum of similar to 20% non-modal fractional melting, with little variation between sites. As some serpentinite samples are ex situ rubble, the magmatic histories observed at each site are consistent with a local source (from the fault zone) rather than rafted rubble that would be expected to show more heterogeneity and no spatial pattern. In this case, the studied sites may provide a record of enhanced melt-rock interactions with time, consistent with proposed geological models. Alternatively, sites may signify heterogeneities in these processes at spatial scales of a few km.
CRIS-Team WoS Importer:2022-04-08

Geochemistry of the Oceanic Crust - Haase, Karsten (John Wiley and Sons, 2011)
The oceanic crust has an average thickness of 7 km and forms by decompression melting of peridotitic rocks of the upper mantle at divergent plate boundaries, so - called mid - ocean ridges. The oceanic crust consists of tholeiitic basalts and gabbros, typically with low concentrations of incompatible elements like K, U and the light rare - earth elements. Evolved rocks like rhyolites or andesites and their plutonic equivalents are rare in the oceanic crust. Variations in the composition of the mafi c rocks are due to variable degrees and depths of partial melting and chemical heterogeneities in the upper mantle. The chemical heterogeneities often contain higher concentrations of incompatible elements than the upper - mantle peridotites, and refl ect upwelling of relatively hot deep mantle plumes causing age - progressive volcanic chains next to the mid - ocean ridges. After crystallization of the magmas, the rocks of the upper part of the oceanic crust chemically react with seawater, leading to metamorphic processes and severe alteration of the uppermost kilometre of the crust. Intrusion and extrusion of intraplate magmas also change the composition of the oceanic crust after its generation at the mid - ocean ridge. ©2011 Blackwell Publishing Ltd. © 2011 Blackwell Publishing Ltd. All rights reserved.
Keywords: Assimilation-fractional crystallization (AFC); Depleted MORB Mantle (DMM); Geochemistry of the Oceanic Crust; Mantle Sources of the Oceanic Crust; Oceanic Crust Formation: Melting and Differentiation Processes at Mid - Ocean Ridges; Overlapping spreading centres (OSC); The Chemical Evolution of the Oceanic Crust; The Structural Framework of the Ocean Crust

Geochemistry of the sheeted dyke complex, Troodos Ophiolite (Cyprus): Evidence for the magmatic evolution during subduction initiation - Lehmann, Wiebke; Regelous, Marcel; Haase, Karsten; Keith, Manuel; Woelki, Dominic (Chemical Geology, 2025)
Supra-subduction zone (SSZ) ophiolites, including the Troodos Ophiolite of Cyprus contain magmatic rocks with geochemical compositions indicating that they formed close to a subduction zone. However, the exact tectonic setting in which SSZ ophiolites were formed is debated, although it has been proposed that they represent fragments of fore-arc crust formed during subduction initiation. The sheeted dyke complex of an ophiolite provides information about the orientation and distance of the spreading axis relative to the slab. This study combines new and published geochemical data for the Troodos sheeted dyke complex with published data for volcanic glasses from the overlying lavas. We show that the sheeted dykes are generally tholeiitic compared to the tholeiitic to boninitic lavas, and most are less depleted (higher Zr/Yb) and contain less slab component (higher Ce/Pb) than the abundant boninitic Troodos lavas. This implies that the crust of the Troodos Ophiolite formed more distant from the trench than the off-axis boninites that mainly occur in the south of the ophiolite. Many of the Troodos dykes have compositions similar to fore-arc basalts from the Izu-Bonin-Mariana island arc, which were erupted during subduction initiation. Lavas equivalent to the sheeted dykes may exist in the lowermost lava pile of the Troodos Ophiolite. The observed geochemical evolution of Troodos from fore-arc basalt to boninite and tholeiite with a strong slab input resembles the stratigraphy of the Izu-Bonin-Mariana fore-arc. We suggest that the Troodos Ophiolite formed at a laterally propagating trench-ridge ‘double junction’ during subduction initiation.
CRIS-Team Scopus Importer:2025-04-01
Keywords: Boninites; Sheeted dykes; Subduction initiation; Tholeiites; Troodos Ophiolite

Geochemistry of volcanic glasses from the Louisville Seamount Trail (IODP Expedition 330): Implications for eruption environments and mantle melting - Nichols, Alexander R.L.; Beier, Christoph; Brandl, Philipp; Buchs, David M.; Krumm, Stefan (Geochemistry Geophysics Geosystems, 2014)
Volcanic glasses recovered from four guyots during drilling along the Louisville Seamount Trail, southwest Pacific, have been analyzed for major, trace, and volatile elements (HO, CO, S, and Cl), and oxygen isotopes. Compared to other oceanic island settings, they are geochemically homogeneous, providing no evidence of the tholeiitic stage that characterizes Hawai'i. The degrees and depth of partial melting remained constant over 1-3 Ma represented by the drill holes, and along-chain over several million years. The only exception is Hadar Guyot with compositions that suggest small degree preferential melting of an enriched source, possibly because it erupted on the oldest and thickest lithosphere. Incompatible element enriched glass from late-stage volcaniclastics implies lower degrees of melting as the volcanoes moved off the melting anomaly. Volcaniclastic glasses from throughout the igneous basement are degassed suggesting generation during shallow submarine eruptions (<20 mbsl) or as subaerial flows entered the sea. Drill depths may no longer reflect relative age due to postquench downslope movement. Higher volatile contents in late-stage volcaniclastics indicate submarine eruptions at 118-258 mbsl and subsidence of the edifices below sea level by the time they erupted, or generation in flank eruptions. Glass from intrusion margins suggests emplacement 100 m below the surface. The required uplift to achieve these paleo-quench depths and the subsequent subsidence to reach their current depths exceeds that expected for normal oceanic lithosphere, consistent with the Louisville melting anomaly being <100C hotter than normal asthenosphere at 50-70 Ma when the guyots were erupted. © 2014. American Geophysical Union. All Rights Reserved.
Keywords: eruption environments; intraplate melting dynamics; major and trace elements; mantle thermal anomaly; uplift and subsidence

Geochronological evidence for Archaean and Palaeoproterozoic polymetamorphism in the Central Zone of the Limpopo Belt, South Africa - Kröner, Alfred; Brandl, Guenther; Brandt, Sönke; Klemd, Reiner; Xie, Hangqiang (Precambrian Research, 2018)
The Central Zone of Limpopo Belt is a polymetamorphic and complexly deformed Precambrian terrane whose tectonic evolution is still uncertain because details on the timing of its evolution are not well established. We report zircon ages for newly discovered rocks in the Central Zone which document three distinct high-grade tectono-metamorphic events at 3.22, 2.62 and 2.02 Ga. The youngest of these has been well established, but the older two events were so far largely based only on rare zircon overgrowth rims. Most of our samples were collected from a large enclave in the 2.61 Ga Bulai pluton and constitute a strongly deformed, brecciated high-grade assemblage of supracrustal rocks, meta-anorthosite and granitoid gneisses, some of which are most likely equivalents of the pre-3.33 Ga Beit Bridge Complex. Magmatic zircon ages of 3.34–3.33 Ga for anorthositic and tonalitic gneisses in the enclave breccia support this correlation. Ca. 3.22 Ga metamorphic zircons, possibly reflecting the D1/M1 event, were only found in one felsic granulite sample, and their regional significance remains uncertain. Abundant metamorphic zircons grew at ca. 2.62 Ga under granulite-facies conditions (D2/M2), and some of these experienced variable degrees of recrystallization and/or Pb-loss during the third granulite-facies event at ca. 2.0 Ga (D3/M3). Rocks outside the Bulai enclave contain abundant newly-formed ca. 2.02 Ga metamorphic zircons but only rarely preserve evidence for the ca. 2.62 Ga event since these late Archaean zircons show strong recrystallization and/or Pb-loss at ca. 2.0 Ga. We suggest that the Bulai pluton “protected” the rocks inside the enclave from severe overprinting at ca. 2.0 Ga because these rocks remained dry, whereas the assemblages outside the Bulai pluton experienced fluid-assisted metamorphic overprinting at ca. 2.0 Ga. Our new data sugggest that the tectonic evolution of the Central Zone was more complex than previously thought. We favour a scenario where collision involving the Limpopo Belt occurred in the Neoarchaean, whereas the high-grade Palaeoproterozoic event was most likely intracontinental and records far-field effects of plate movements elsewhere. The tectonic setting controlling the early Archaean D1/M1 event remains unknown, largely because of insufficient data and extensive overprinting during later time

Geochronology and geochemistry of granitoid rocks from the Zhibo syngenetic volcanogenic iron ore deposit in the Western Tianshan mountains (NW-China): Constraints on the age of mineralization and tectonic setting. - Zhang, Xi; Tian, Jingquan; Gao, Jun; Klemd, Reiner; Dong, Lianhui; Fan, Junjia; Jiang, Tuo; Hu, Chengjian; Qian, Qing (Gondwana Research, 2012)
Several large syngenetic volcanogenic iron ore deposits including the Chagangnuoer Fe-Cu, the Zhibo Fe and the Beizhan Fe deposits occur in the Awulale Fe-Cu Metallogenetic Belt (AMB) which is located in the southeastern corner of the Yili block in the Western Tianshan Mountains (NW-China). In the present study, we report geochronological and geochemical data for granitoid rocks associated with the Zhibo iron ore deposit in order to constrain the age of the stratiform Fe mineralization and tectonic setting of this deposit. Laser ablation-ICPMS (LA-ICPMS) U-Pb zircon ages of 318.9±1.5Ma and 304.1±1.8Ma were obtained for a diorite and a granite pluton, respectively, both of which intruded the volcanic-volcaniclastic rocks of the Early Carboniferous Dahalajunshan Formation. Additional LA-ICPMS U-Pb zircon ages of 320.3±2.5Ma and 294.5±1.6Ma were obtained for two crosscutting granite dikes, respectively. The ca. 319Ma diorite has a high-potassium calc-alkaline, weakly peraluminous composition and is characterized by large ion lithophile element (LILE) and light rare earth element (LREE) enrichment and flat heavy rare earth element (HREE) patterns. It further shows distinct negative anomalies of Nb, Ta and Ti. In contrast, the ca. 304Ma granite classifies as A 2 type granite and is characterized by an enrichment of LILE and LREE, flat HREEs and distinct negative anomalies of Ba, Nb, Ta and Ti. The ca. 320Ma granite dike has a low-potassium and weakly peraluminous composition and is characterized by LILE and LREE enrichment and a distinct depletion of Nb, Ta, Ti and HREE. The ca. 295Ma granite displays a high-potassium calc-alkaline and weakly peraluminous composition and is characterized by a slight enrichment of LILE and LREE, flat HREEs and a distinct depletion of Nb, Ta and Ti. The data presented here in conjunction with previously published data suggest a submarine, syngenetic volcanogenic mineralization age of ca. 320Ma for the Zhibo iron ore deposit. The Zhibo and other submarine volcanogenic iron ore deposits of the AMB are inferred to have formed in a continental arc-setting related to subduction tectonics. Furthermore, post-collisional granitic magmatism from 304 to 295Ma was superimposed on the entire AMB. © 2011 .
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.c3geoc.geochr
Keywords: Granitoid rocks; The Zhibo iron ore deposit; Tianshan; U-Pb zircon ages

Geochronology and petrogenesis of Eocene gabbros and granitic rocks of the eastern Gangdese belt, southern Tibet: Implications for the timing of India-Asia collision - Shui, Xin Fang; Klemd, Reiner; He, Zhen Yu; Mao, Jing Wen; Zhao, Yuan Yi (Gondwana Research, 2021)
The Palaeocene-Eocene (66–41 Ma) hosts the most intense stage of extensive magmatism in the Gangdese belt of southern Tibet. However, the magma sources and tectonic setting of this magmatic belt have been a matter of discussion for decades. In this study, we conducted zircon geochronological and geochemical studies on Eocene gabbroic rocks and granitic rocks from the Jiacha area in the eastern Gangdese belt. Laser ablation-ICP-MS zircon U–Pb dating suggests almost synchronous crystallization ages of 50–47 Ma for both rock types. Geochemically, the gabbroic rocks have low total rare earth elements and high positive zircon εHf(t) values (from +8.4 to +15.0), indicating that the parental magma was derived from an isotopically depleted mantle. The granitic rocks are magnesian calc-alkalic to calcic granites that are characterized by variable zircon εHf(t) values (from +3.0 to +10.8), indicating that the magmas were generated by differentiation of a mantle-derived magma with variable contributions from ancient crustal materials. Furthermore, an enlarged database of 66–41 Ma plutonic rocks and coexisting Linzizong volcanic rocks reveals an evolutionary trend from mafic to silicic rocks. The zircon Hf and Nd isotopic compositions become more evolved with increasing whole-rock SiO2. The whole-rock and isotope geochemistry of the 66–41 Ma plutonic rocks and the Linzizong volcanic rocks indicate an origin and evolution of these rocks in an active continental margin setting. Therefore, we argue that the Gangdese belt was associated with the subduction of the Neo-Tethyan Oceanic plate throughout the Early Eocene, thereby implying that the initial India-Asia collision occurred after 41 Ma.
CRIS-Team Scopus Importer:2021-06-18
Keywords: Gangdese belt; Neo-Tethyan Oceanic subduction; Palaeocene-Eocene; Volcanism–Plutonism link

Geochronology and Zr-in-rutile thermometry of high-pressure/low temperature metamorphic rocks from the Bantimala complex, SW Sulawesi, Indonesia - Boehnke, Mischa; Broecker, Michael; Maulana, Adi; Klemd, Reiner; Berndt, Jasper; Baier, Heidi (Lithos, 2019)
The timeframe of eclogite- and blueschist-facies metamophism in the central Indonesian region is poorly defined. Relative to its geographic extent, the regional coverage of isotopic age data is insufficient for an unambiguous interpretation of the geologic evolution of the Central Indonesian Accretionary Collision Complex. This study reports new geochronological constraints for high-pressure/low-temperature (HP/LT) rocks from the Bantimala Complex, SW Sulawesi, which further substantiate the importance of Cretaceous HP/LT metamorphism for the larger region. Multipoint Rb–Sr mineral isochrons of eclogites and glaucophane-rich rocks display a narrow range of white mica ages (130–120 Ma), interpreted to postdate peak-HP conditions, which is considerably smaller and more precise than the previously published K–Ar age spectrum (137–113 Ma). The close similarity with K–Ar ages suggests that these analyses were only slightly contaminated, if at all, with an extraneous Ar component, which did not significantly compromise the geological relevance of the existing dataset. An important result of this study is the emerging evidence for regional age differences between HP/LT rocks from SW Sulawesi (130–120 Ma) and Java (ca. 118 Ma). The existence of different subduction zones cannot be excluded but P–T and age differences between these occurrences can be reconciled with a model suggesting formation in the same subduction complex. Zircon is very rare in the studied HP/LT rock suite, but two glaucophane-rich rocks were suitable for U–Pb zircon dating and indicate Late Triassic–Early Jurassic protolith ages (ca. 205–185 Ma). The zircon population of a retrogressed eclogite records a more complex history including evidence for igneous crystallization, metamorphic recrystallization or growth, inheritance and variable degrees of Pb-loss. Metamorphic zircon rims mostly yielded U–Pb ages in the 135–110 Ma range that broadly confirm metamorphic ages determined by K–Ar and Rb–Sr white mica geochronology. Zircons that are significantly older (2.55–1.4 Ga and 400–260 Ma) than the protolith age are interpreted to represent detrital grains from subducted sediments that had been incorporated in mafic melts directly derived from a contaminated mantle source. The presence of continentally-derived detrital zircons that have presumably been included during melt formation in the mantle have not yet been described for any eclogite- and/or blueschist-facies rock of basaltic or gabbroic parentage.<br
CRIS-Team WoS Importer:2019-02-21
Keywords: Bantimala complex; Indonesia; Eclogite; Blueschist; Geochronology

Geochronology, geochemistry and tectonic implications of Variscan granitic and dioritic rocks from the Odenwald-Spessart basement, Germany - Will, Thomas M.; Schmädicke, Esther; Ling, Xiao-Xiao; Li, Xian-Hua; Li, Qiu-Li (Lithos, 2021)
New zircon U-Pb-Hf-O isotope, whole rock geochemical and Sr-Nd-Pb isotope geochemical data of Variscan felsic to intermediate rocks from the Odenwald-Spessart basement, Mid-German Crystalline Zone, Germany are presented. Peraluminous, high-K calc-alkaline S-type granite in the eastern Odenwald basement (Group 1 rocks) formed by partial melting of the lower crust at c. 425 Ma. Their high-K calc-alkaline composition indicates the presence of sedimentary and/or metasomatized lithospheric mantle material during formation of the melts. The protolithic melts of metaluminous, medium-to high-K calc-alkaline I-type granodiorite and diorite of the Spessart and western Odenwald basement as well as the Neustadt (Odenwald) outlier (Group 2 rocks) formed by partial melting of the upper mantle at c. 340 Ma. The melt source was enriched through previously subducted Mesoproterozoic sedimentary material. Eastern Odenwald basement leucocratic gneiss have zircon with ages ranging from 2803 Ma to 336 Ma and main age peaks between 620 and 570 Ma and 360 and 330 Ma. The presence of numerous >1800 Ma old zircon and a prominent age gap between 1800 and 1000 Ma imply a Gondwanan zircon source and indicate the presence of Cadomian material in the Odenwald-Spessart basement. Group 2 diorite is exposed over a distance of at least 60 km from the easternmost Spessart to the westernmost Odenwald and is expected to underlie the eastern Odenwald basement. We suggest that Group 2 diorite formation was related to the presence of a mantle plume, which was also responsible for the widespread Carboniferous magmatism and the associated high-temperature metamorphism in the Odenwald-Spessart basement and other areas of the Variscan orogen.
CRIS-Team WoS Importer:2021-10-15

Geochronology of a long Pleistocene sequence at Kilombe volcano, Kenya: from the Oldowan to Middle Stone Age - Hoare, S.; Brink, J. S.; Herries, A. I.R.; Mark, D. F.; Morgan, L. E.; Onjala, I.; Rucina, S. M.; Stanistreet, I. G.; Stollhofen, Harald; Gowlett, J. A.J. (Journal of Archaeological Science, 2021)
We report a newly extended stratigraphic sequence with associated Palaeolithic sites from the area of the extinct Kilombe volcano in central Kenya. The extended archaeological sequence runs from Oldowan finds, through the Acheulean, and up to the Middle Stone Age. The sedimentary sequences within the Kilombe caldera and south flanks of the mountain have been dated through 40Ar/39Ar measurements and palaeomagnetic studies. A series of 40Ar/39Ar values date the geological sequence from 2.493 ± 0.095 Ma, near the beginning of the Lower Pleistocene, through to 0.118 ± 0.030 Ma near the Middle to Upper Pleistocene transition. It includes the first entirely new area of Oldowan localities in East Africa south of Ethiopia for thirty years, and the first in a rugged mountainous setting. Trachyte lavas of Kilombe mountain were extruded during and after c. 2.5 Ma, followed by formation of a caldera and subsequent caldera lake, and sedimentation of a sequence of tuffs, diamictites, sandstones, and claystones. Sections in the mid-part of this intra-caldera fill-sequence have produced dates of 1.8–1.7 Ma, associated with an Oldowan industry and fauna dated precisely at 1.814 ± 0.004, and overlain by Acheulean finds at higher level. On the southern outward flanks of Kilombe mountain, a second major sequence is bounded at the base by trachyphonolite and a tuff yielding dates in the range 1.58–1.50 Ma. The main Acheulean archaeological site (GqJh1) falls within the overlying sedimentary sequence and has an age of c. 1.0 Ma, on the basis of a new 40Ar/39Ar date for the Three-Banded Tuff and palaeomagnetic reversal stratigraphy. Further 40Ar/39Ar dates indicate an age of c. 0.48–0.46 Ma for a marker ashflow tuff (AFT), prominent across the area. At Moricho, west of Kilombe, sediments above the AFT have been dated in the range 270,000–120,000 years and are associated with Middle Stone Age assemblages. In total, these sites attest to hominin activity from an Oldowan horizon dated to 1.8 Ma up to Later Stone Age stone scatters within the last 100,000 years.
CRIS-Team Scopus Importer:2020-12-04
Keywords: Acheulean; Argon–argon dating; Middle Stone Age; Oldowan; Palaeomagnetism; Paleoenvironments; Rift valley

Geochronology of igneous rocks in the Sierra Norte de Córdoba (Argentina): implications for the Pampean evolution at the western Gondwana margin. - von Gosen, Werner; Mcclelland, W. C.; Loske, W.; Martinez, J. C.; Prozzi, C. (Lithosphere, 2014)
UnivIS-Import:2015-10-26:Pub.2014.nat.dgeo.IGM.LG.geochr

Geodynamic constraints from glass geochemistry in the Troodos ophiolite - Wölki, Dominic; Regelous, Marcel; Haase, Karsten; Beier, Christoph (GeoBremen2017, 2017)
Ophiolites represent fragments of oceanic crust formed at spreading ridges and have been used to infer on the processes at mid-ocean ridges in the past. Many ophiolites were suggested to have formed in a ‘supra-subduction zone’ environment indicated by the characteristic enrichment in fluid-soluble elements relative to Rare Earth Elements compared to mid-ocean ridge basalts (MORB). But the precise tectonic is still debated. Here, we present microanalytical measured major and trace element data along with Sr and Pb isotopes of fresh volcanic glasses from traverses through the pillow lava sequence of the Troodos ophiolite. Glasses from the northern margin of the Troodos ophiolite display a large range in trace element and isotope composition. The range from tholeiitic basalts to andesitic and dacitic lavas that all have relatively low Pb/Ce ratios (0.13) indicating a subtle subduction zone component. They are also more depleted compared to normal depleted MORB (Sm/Yb = 0.87). The other Troodos glasses form a continuous array from less depleted tholeiitic to strongly depleted boninitic lavas (Sm/Yb = 0.24) that display greater influence from a subduction zone fluid component (Pb/Ce = 0.77). This source has subsequently been re-enriched by small degree sediment melts (high Nb/La = 2.94). Strontium and Pb isotope ratios increase with decreasing Sm/Yb and increasing Pb/Ce and Nb/La. The most depleted lavas with the highest subduction zone input occur south of the Arakapas Transform Fault suggesting that the former subduction zone was situated south of the present-day southern margin of the Troodos ophiolite. The paleo-spreading direction (east-west) was not parallel to the subduction zone and may represent a back-arc spreading ridge that propagated into arc crust. These observations seem to preclude an origin for the Troodos ophiolite during subduction initiation. Further detailed profiles through the Troodos lava pile are currently under work to test this hypothesis.

Geodynamic evolution of the south Tianshan orogen: Geochronological and geochemical constraints from granitic and mafic dikes - Jiang, Tuo; Gao, Jun; Klemd, Reiner; Wang, Xinshui; Li, Jilei; Tong, Xirun (Lithos, 2025)
Giant mafic and granitic dike swarms can provide invaluable insight into the paleo-geographic reconstruction of supercontinents and the identification of mantle plumes. Although some case studies of orogeny-related dikes have been undertaken, rare systematic information is available concerning the relationship between the formation mechanism of the dikes and orogenesis. In this study, we conducted a detailed geological, geochronological and geochemical study on recently identified granitic and mafic dikes close to the Wuwamen ophiolite complex in the Chinese South Tianshan, aiming to reveal the link between the formation of the dikes and the orogenic evolution. A dike swarm comprising 456 Ma biotite granite dikes, 423 Ma alkali feldspar granite dikes and a 301 Ma diabase dike crosscuts the Xieliwancaikai gneissic diorite with a zircon U[sbnd]Pb age of 475 Ma. In addition, a 301 Ma granite porphyry dike extends across the middle Devonian meta-sedimentary strata in the Tianqiao area. The geochemical characteristics of the biotite granite and the alkali feldspar granite dikes and their gneissic diorite host suggest that the granitic magma was produced by lower crustal melting. However, the granite porphyry dike has chemical characteristics resembling those of S-type granites commonly produced by partial melting of overthickened crust in collisional orogenic belts. Furthermore, the mafic magma source of the diabase dike resulted from low-degree partial melting of a fertilized sub-continental lithospheric mantle. In conjunction with previously published data on the Wuwamen ophiolite Complex, we propose that the 456 Ma metaluminous granite dike reflects the subduction onset of the South Tianshan Ocean, while the 423 Ma metaluminous granite dike represents the felsic arc melts generated during the subsequent subduction. The 321–313 Ma peraluminous mica granite dikes are thought to have formed during the collision between the Tarim and Kazakhstan–Yili–Central Tianshan blocks. In addition, the peraluminous granite, the strongly peraluminous granite porphyry and the diabase dikes that formed between 307 and 301 Ma were generated in a post-collisional extensional environment. Therefore, bimodal dike swarms provide crucial constraints on the geodynamic evolution of orogens.
CRIS-Team Scopus Importer:2025-02-28
Keywords: Diabase; Dike; Granite; Orogenic tectonics; South Tianshan

Geographical distribution and extinction risk: Lessons from Triassic-Jurassic marine benthic organisms - Kießling, Wolfgang; et al. (Journal of Biogeography, 2007)
Aim: To evaluate the influence of geographical distribution on the extinction risk of benthic marine invertebrates using data from the fossil record, both during times of background extinction and across a mass-extinction episode. Total geographical range is contrasted with proxies of global abundance to assess the relationships between the two essential components of geographical distribution and extinction risk. Location: A global occurrence data base of fossil benthic macro-organisms from the Triassic and Jurassic periods was used for this study. Methods: Geographical distributions and biodiversity dynamics were assessed for each genus (all taxa) or species (bivalves) based on a sample-standardized data set and palaeogeographical reconstructions. Geographical ranges were measured by the maximum great circle distance of a taxon within a stratigraphic interval. Global abundance was assessed by the number of localities at which a taxon was recorded. Widespread and rare taxa were separated using median and percentile values of the frequency distributions of occurrences. Results: The frequency distribution of geographical ranges is very similar to that for modern taxa. Although no significant correlation could be established between local abundance and geographical range, proxies of global abundance are strongly correlated with geographical range. Taxon longevities are correlated with both mean geographical range and mean global abundance, but range size appears to be more critical than abundance in determining extinction risk. These results are valid when geographical distribution is treated as a trait of taxa and when assessed for individual geological stages. Main conclusions: Geographical distribution is a key predictor of extinction risk of Triassic and Jurassic benthic marine invertebrates. An important exception is in the end-Triassic mass extinction, which equally affected geographically restricted and widespread genera, as well as common and rare genera. This suggests that global diversity crises may curtail the role of geographical distribution in determining extinction risk. © 2007 The Authors.
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LP.geogra
Keywords: Abundance; Background extinction; Geographical range; Jurassic; Marine invertebrates; Mass extinction; Origination; Triassic

Geographical limits to species-range shifts are suggested by climate velocity - Burrows, Michael T.; Schoeman, David S.; Richardson, Anthony J.; Molinos, Jorge Garcia; Hoffmann, Ary; Buckley, Lauren B.; Moore, Pippa J.; Brown, Christopher J.; Bruno, John F.; Duarte, Carlos M.; Halpern, Benjamin S.; Hoegh-Guldberg, Ove; et al. (Nature, 2014)
The reorganization of patterns of species diversity driven by anthropogenic climate change, and the consequences for humans, are not yet fully understood or appreciated. Nevertheless, changes in climate conditions are useful for predicting shifts in species distributions at global and local scales. Here we use the velocity of climate change to derive spatial trajectories for climatic niches from 1960 to 2009 (ref. 7) and from 2006 to 2100, and use the properties of these trajectories to infer changes in species distributions. Coastlines act as barriers and locally cooler areas act as attractors for trajectories, creating source and sink areas for local climatic conditions. Climate source areas indicate where locally novel conditions are not connected to areas where similar climates previously occurred, and are thereby inaccessible to climate migrants tracking isotherms: 16% of global surface area for 1960 to 2009, and 34% of ocean for the 'business as usual' climate scenario (representative concentration pathway (RCP) 8.5)8 representing continued use of fossil fuels without mitigation. Climate sink areas are where climate conditions locally disappear, potentially blocking the movement of climate migrants. Sink areas comprise 1.0% of ocean area and 3.6% of land and are prevalent on coasts and high ground. Using this approach to infer shifts in species distributions gives global and regional maps of the expected direction and rate of shifts of climate migrants, and suggests areas of potential loss of species richness. © 2014 Macmillan Publishers Limited.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LP.geogra

Geographie des Todes - Kießling, Wolfgang (Theatrum naturae, 2001)
Keywords: Geographie

Geological CO2 quantified by high-temporal resolution stable isotope monitoring in a salt mine - Frank, Alexander; van Geldern, Robert; Myrttinen, Anssi; Zimmer, Martin; Barth, Johannes; Strauch, Bettina (Scientific Reports, 2020)
The relevance of CO2 emissions from geological sources to the atmospheric carbon budget is becoming increasingly recognized. Although geogenic gas migration along faults and in volcanic zones is generally well studied, short-term dynamics of diffusive geogenic CO2 emissions are mostly unknown. While geogenic CO2 is considered a challenging threat for underground mining operations, mines provide an extraordinary opportunity to observe geogenic degassing and dynamics close to its source. Stable carbon isotope monitoring of CO2 allows partitioning geogenic from anthropogenic contributions. High temporal-resolution enables the recognition of temporal and interdependent dynamics, easily missed by discrete sampling. Here, data is presented from an active underground salt mine in central Germany, collected on-site utilizing a field-deployed laser isotope spectrometer. Throughout the 34-day measurement period, total CO2 concentrations varied between 805 ppmV (5th percentile) and 1370 ppmV (95th percentile). With a 400-ppm atmospheric background concentration, an isotope mixing model allows the separation of geogenic (16–27%) from highly dynamic anthropogenic combustion-related contributions (21–54%). The geogenic fraction is inversely correlated to established CO2 concentrations that were driven by anthropogenic CO2 emissions within the mine. The described approach is applicable to other environments, including different types of underground mines, natural caves, and soils.
CRIS-Team Scopus Importer:2020-12-04

Geologic and biologic controls on the evolution of reefs - Kießling, Wolfgang (Annual Review of Ecology Evolution and Systematics, 2009)
The shallow, tropical reef environment differs from other marine environments in its more intense competition for space, more limited nutrient concentrations, proliferation of clonal animals, and greater habitat complexity. The evolutionary consequences of these ecologic peculiarities are still poorly understood, but they seem to cause greater turnover rates of reef taxa than nonreef taxa and an especially volatile record of reefs on geologic timescales. The boom and bust pattern of Phanerozoic reef construction is impossible to explain by linear responses to physicochemical changes. Threshold effects appear to be involved not only in reef crises but also in reef expansions. Long-term climate change seems to influence the biotic composition of reefs, but neither climate nor sea-level nor chemical changes in the oceans can elucidate the waxing and waning of reefs. Biological factors affecting spatial competition are thus probably more important than geologic controls on reef evolution. Copyright © 2009 by Annual Reviews. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.LP.geolog
Keywords: Climate change; Corals; Habitat area; Macroevolutionary resilience; Mass extinctions; Nutrients; Photosymbiosis

Geologic and Structural Evolution of the NE Lau Basin, Tonga: Morphotectonic Analysis and Classification of Structures Using Shallow Seismicity - Anderson, Melissa O.; Norris-Julseth, Chantal; Rubin, Kenneth H.; Haase, Karsten; Hannington, Mark D.; Baxter, Alan T.; Stewart, Margaret S. (Frontiers in Earth Science, 2021)
The transition from subduction to transform motion along horizontal terminations of trenches is associated with tearing of the subducting slab and strike-slip tectonics in the overriding plate. One prominent example is the northern Tonga subduction zone, where abundant strike-slip faulting in the NE Lau back-arc basin is associated with transform motion along the northern plate boundary and asymmetric slab rollback. Here, we address the fundamental question: how does this subduction-transform motion influence the structural and magmatic evolution of the back-arc region? To answer this, we undertake the first comprehensive study of the geology and geodynamics of this region through analyses of morphotectonics (remote-predictive geologic mapping) and fault kinematics interpreted from ship-based multibeam bathymetry and Centroid-Moment Tensor data. Our results highlight two notable features of the NE Lau Basin: 1) the occurrence of widely distributed off-axis volcanism, in contrast to typical ridge-centered back-arc volcanism, and 2) fault kinematics dominated by shallow-crustal strike slip-faulting (rather than normal faulting) extending over ∼120 km from the transform boundary. The orientations of these strike-slip faults are consistent with reactivation of earlier-formed normal faults in a sinistral megashear zone. Notably, two distinct sets of Riedel megashears are identified, indicating a recent counter-clockwise rotation of part of the stress field in the back-arc region closest to the arc. Importantly, the Riedel structures identified in this study directly control the development of complex volcanic-compositional provinces, which are characterized by variably-oriented spreading centers, off-axis volcanic ridges, extensive lava flows, and point-source rear-arc volcanoes. This study adds to our understanding of the geologic and structural evolution of modern backarc systems, including the association between subduction-transform motions and the siting and style of seafloor volcanism.
CRIS-Team Scopus Importer:2021-07-09
Keywords: back-arc; centroid moment tensors; geologic mapping; megashear; morphotectonic analysis; NE lau basin; submarine volcanism

Geologischen Strukturen auf der Spur. Plädoyer für eine geologische Kartierung mit Schülern - Pingold, Markus; Mennecke, Erek; Regelous, Anette (Praxis Geographie, 2013)

Geology of northeast Ellesmere Island adjacent to Kane Basin and Kennedy Channel, Nunavut. - Lee, Carmen; Lehnert, Oliver; Nowlan, Godfrey (Bulletin of the Geological Survey of Canada, 2008)
UnivIS-Import:2015-03-09:Pub.2008.nat.dgeo.IGM.LG.cretac

Geomorphology and sand provenance of the Tyrrhenian coast between Capo Suvero and Gizzeria (Calabria, southern Italy) - Caracciolo, Luca; et al. (Rendiconti Online Societa Geologica Italiana, 2012)
Keywords: Calabria; Sandy petrofacies; Shoreline evolution; Spit; Tyrrhenian coast

Geophysical monitoring for shallow geothermal applications–two Italian case histories - Arato, Alessandro; Boaga, Jacopo; Comina, Cesare; De Seta, Massimiliano; Di Sipio, Eloisa; Galgaro, Antonio; Giordano, Nicolò; Mandrone, Giuseppe (First Break, 2015)

GeoSurf-geoelectric soil modelling for a sustainable land use and efficient planning of shallow geothermal systems. - Bertermann, David; Walker-Hertkorn, Simone; Kübert, Markus; Schmidt, David; Di Sipio, Eloisa; Müller, Johannes; Schwarz, Hans (Vol. 18, 2016)

GeoSurf - Neuentwicklung eines Messgerätes zur Dimensionierung oberflächennaher geothermischer Anlagen - Schwarz, Hans; Kübert, Markus; Walker-Hertkorn, Simone; Schmidt, David; Bertermann, David (B_I umweltbau, 2017)

GeoSurf - Neuentwicklung eines Messgerätes zur Dimensionierung sehr oberflächennaher geothermischer Anlagen - Schwarz, Hans; Bertermann, David; Walker-Hertkorn, Simone; Kübert, Markus; Schmidt, David (bbr - Leitungsbau, Brunnenbau, Geothermie, 2018)

GeoSurf - Neuentwicklung eines Messgerätes zur Planung von oberflächennahen geothermischen Anlagen - Bertermann, David; Walker-Hertkorn, Simone; Kübert, Markus; Schmidt, David; Schwarz, Hans (Bodenschutz beim Planen und Bauen, 2016)

GeoSurf - The development of a new measuring tool for an efficient planning of shallow geothermal systems - Bertermann, David; Walker-Hertkorn, Simone; Kübert, Markus; Schmidt, David; Schwarz, Hans; Müller, Johannes (European Geothermal Congress 2016, 2016)
Keywords: Geologie; erneuerbare Energiequelle

Geothermal energy as a means to decarbonize the energy mix of megacities - Vargas, Carlos A.; Caracciolo, Luca; Ball, Philip J. (Communications Earth & Environment, 2022)
Geothermal energy can provide enough power to serve the current and future needs of megacities such as Bogota, Los Angeles and Jakarta and also provide flexibility and baseload capacity, according to an assessment of the geothermal resource base in each city.
CRIS-Team WoS Importer:2022-04-01

Geothermie und Grundwasser - Zosseder, Kai; Bertermann, David (Grundwasser, 2024)
CRIS-Team Scopus Importer:2025-02-04

Geothermisches Know-How in der oberflächennahen Geothermie - Bertermann, David; Müller, Johannes (2018)

Geowissenschaftliche Sammlungen - Höfling, Richard; Schulbert, Christian; Baier, Alfons (Die Sammlungen der Universität Erlangen-Nürnberg. Begleitband zur Ausstellung "Ausgepackt. Die Sammlungen der Universität Erlangen-Nürnberg" 20. Mai bis 29. Juli 2007, 2007)
UnivIS-Import:2015-04-20:Pub.2007.nat.dgeo.IGM.LAG.geowis

German paleontology in the early 21st century. - Kießling, Wolfgang; Nützel, Alexander (Palaeontologia Electronica, 2010)
German paleontology has a long tradition and is still very active and innovative in many fields. Fields with the highest impacts are Neogene to Recent micropaleontology with paleoceanographic and climate focus as well as geobiology and paleoecology. Systematic paleontology is well represented in Germany and leading taxonomic exper- tise is present for many groups although the impact of this resear ch is necessarily low. Conservation of this expertise is important but visibility should be enhanced by cooper- ation with researchers from other disciplines . Analytical paleobiology is too weak in Germany with a few exceptions, as is the de ep-time perspective of evo-devo research and efforts should be made not to fall further behind here. The greatest risk for German paleontology is the continued closure of university departments and the replacement of retired paleontologists by non-paleontologists. This threatens the future of our students in science and the paleontological research community may fall below a critical mass which is needed for innovative research. Some of these problems fa ll in the responsibility of th e paleontologists themselves (e.g., lack of innovative approaches, appare nt absence of practical/ economic applica- bility, tactical mistakes) but others are the re sult of administrative actions to save or shift resources independent of the quality of research and teaching.
Keywords: Germany; Palaeontology; Academics

Gesteinsmagnetische Untersuchungen an Doggersandsteinen (Süddeutschland, Fränkische Alb) - Schaarschmidt, Anna; Saßenscheidt, Marlen; Scharfenberg, Lars; de Wall, Helga; Gabriel, Gerald (Geologische Blätter für Nordost-Bayern und angrenzende Gebiete, 2015)
Die »Eisensandsteine« des Braunen Jura (Dogger β) sind in der Fränkischen Alb weitverbreitet. Limonit-schalige Ooide sind in diesen Quarz- und Karbonatsandsteinen in unterschiedlicher Konzentration enthalten. Konzentriert sind Fe-Gehalte in gering mächtigen Flözen (bis ca. 50 cm) mit Anreicherung bis zu 40 Gew.%, die unregelmäßige Lagen und Körper bilden. Die magnetischen Suszeptibilitätsdaten reflektieren die variierenden Fe-Gehalte mit durchschnittlichen Werten von 85 · 10-6 SI in den gelben Sandsteinen und 292 · 10-6 SI in den rot-schwarzen Sand steinen. Die höchsten Werte von im Mittel 432 · 10-6 SI zeigen die Limonitsandsteine (grüner Sandstein). Da das Eisen an paramagnetische und anti ferromagnetische Phasen (Limonit, Goethit, untergeordnet Hämatit) gebunden ist, werden nur niedrige Suszeptibilitäten (< 10-3 SI) gemessen. Anisotropiemessungen dokumentieren mit stark oblaten Formen das Schichtungsgefüge der Eisenooide, es sind jedoch auch innerhalb der Schichtflächen Vorzugsrichtungen erkennbar, die das Störungsmuster der Bruchschollentektonik in der Region widerspiegeln. Eine Modellierung des Eisensandsteins als Störkörper des Erdmagnetfeldes mit der Geometrie einer 65 m mächtigen, horizontalen Platte ergibt nur einen schwachen Anteil (< 1 nT) an der im fränkischen Raum verorteten Anomalie von bis zu 65 nT. Hier muss von einem maßgeblichen Anteil tiefer liegender, stärker magnetisierter Störkörper ausgegangen werden. Aufgrund der generellen NE-SW Streichrichtung der magnetischen Strukturen kommen hier Einheiten des unterlagernden variszischen Grundgebirges in Betrach
Keywords: Eisensandstein; Fränkische Alb; Magnetik

Gips und Anhydrit als Rohstoff für die Baustoffindustrie - Vorkommen, Abbau und Weiterverarbeitung - Göbbels, Matthias; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen (Jahresberichte und Mitteilungen des Oberrheinischen Geologischen Vereins, 2003)
Kalk, Gips, Anhydrit, Ton und Sand spielen neben anderen Rohstoffen nicht nur als Baustoffe im Laufe der Entwicklung der Menschheit eine wichtige Rolle. Vom ersten luftgetrockneten Lehmziegel bis zu den heutigen modernen Produkten der Baustoff-Industrie hat sich im Laufe der Jahrtausende eine bemerkenswerte Produktentwicklung und Spezialisierung vollzogen. Dies stellt hohe Anforderungen an die Qualität der Rohstoffe, aber auch an die Abbautechniken und besonders an die Weiterverarbeitung. Gips und Anhydrit sind chemisch sehr ähnlich. Als Anhydrit wird das wasserfreie CaSO4 bezeichnet, wogegen Gips zusätzliches Kristallwasser einbaut und als CaSO4 · 2 H2O beschrieben wird. In technischen Produkten tritt auch das sog. Halbhydrat auf, das der Zusammensetzung CaSO4 · 1/2 H2O entspricht. Im Rahmen der Exkursion werden der Anhydrit-Abbau und die Aufbereitung in der Grube Hüttenheim bei Iphofen sowie die Gipsputz- bzw. die Gipskartonplatten-Herstellung in verschiedenen Produktionsbetrieben der Fa. Knauf in der Umgebung des Standortes Iphofen vorgestellt.
UnivIS-Import:2015-03-09:Pub.2003.nat.dgeo.IGM.LM.gipsun

Givetian/Frasnian (Middle/Upper Devonian) transition in the eastern Taurides, Turkey - Ozkan, Recep; Nazik, Atike; Munnecke, Axel; Demiray, Dilek Gulnur; Schindler, Eberhard; Ozbek, Tuba Aydin; Zor, Emine Seker; Yilmaz, Isak; Brocke, Rainer; Sancay, Recep Hayrettin; Wilde, Volker; Yalcin, Mehmet Namik (Turkish Journal of Earth Sciences, 2019)
Devonian strata, including siliciclastic and carbonate rocks that were deposited in shallow marine to coastal environments, are widely distributed in the eastern Taurides of southern Turkey. To document the regional formation of the Givetian (Middle Devonian)/Frasnian (Upper Devonian) boundary, a section in the eastern Taurides was studied in high resolution with regard to biostratigraphy, microfacies, sequence stratigraphy, and the global Frasne Event. The integrated biostratigraphic investigation was based on calcareous benthic foraminifers, ostracods, conodonts, and palynomorphs, which provide a biostratigraphic frame that allows to recognize the Givetian/Frasnian boundary. On the basis of the lithological variation in the outcrop as well as on depositional textures and biotic components as observed in thin sections, fourteen microfacies types of both siliciclastic and carbonate rocks can be distinguished. These microfacies are interpreted to have been deposited in settings that range from distal shelf to lagoonal depositional environments. The sequence stratigraphic interpretation allows to recognize two successive depositional sequences. The first one is a complete sequence including lowstand systems tract deposits, overlain by transgressive systems tract and highstand systems tract deposits. The second sequence is only represented by transgressive systems tract sediments. The Givetian/Frasnian boundary corresponds to the highstand systems tract of Sequence 1. The late Givetian Frasne Event can be detected lithologically and can be compared with other areas. Its position is confirmed biostratigraphically.
CRIS-Team WoS Importer:2019-04-02

Givetian/Frasnian (Middle/Upper Devonian) transition in the eastern Taurides, Turkey - Özkan, Recep; Nazik, Atike; Munnecke, Axel; Saydam Demiray, Dilek Gülnur; Schindler, Eberhard; Aydin Özbek, Tuba; Şeker Zor, Emine; Yilmaz, Isak; Brocke, Rainer; Hayrettin Sancay, Recep; Wilde, Volker; Yalçın, Mehmet Namık (Turkish Journal of Earth Sciences, 2019)
Devonian strata, including siliciclastic and carbonate rocks that were deposited in shallow marine to coastal environments, are widely distributed in the eastern Taurides of southern Turkey. To document the regional formation of the Givetian (Middle Devonian)/ Frasnian (Upper Devonian) boundary, a section in the eastern Taurides was studied in high resolution with regard to biostratigraphy, microfacies, sequence stratigraphy, and the global Frasne Event. The integrated biostratigraphic investigation was based on calcareous benthic foraminifers, ostracods, conodonts, and palynomorphs, which provide a biostratigraphic frame that allows to recognize the Givetian/Frasnian boundary. On the basis of the lithological variation in the outcrop as well as on depositional textures and biotic components as observed in thin sections, fourteen microfacies types of both siliciclastic and carbonate rocks can be distinguished. These microfacies are interpreted to have been deposited in settings that range from distal shelf to lagoonal depositional environments. The sequence stratigraphic interpretation allows to recognize two successive depositional sequences. The first one is a complete sequence including lowstand systems tract deposits, overlain by transgressive systems tract and highstand systems tract deposits. The second sequence is only represented by transgressive systems tract sediments. The Givetian/Frasnian boundary corresponds to the highstand systems tract of Sequence 1. The late Givetian Frasne Event can be detected lithologically and can be compared with other areas. Its position is confirmed biostratigraphically.<br
Keywords: Foraminifers; ostracods; conodonts; palynomorphs; microfacies analysis; sequence stratigraphy; Frasne Event; North Gondwanan margin

Glass science behind lithium silicate glass-ceramics - Lohbauer, Ulrich; Fabris, Débora Cristina Niero; Lubauer, Julia; Abdelmaseh, Samuel; Cicconi, Maria Rita; Hurle, Katrin; de Ligny, Dominique; Götz-Neunhoeffer, Friedlinde; Belli, Renan (Dental Materials, 2024)
Objectives: Lithium silicate-based glass ceramics have evolved as a paramount restorative material in restorative and prosthetic dentistry, exhibiting outstanding esthetic and mechanical performance. Along with subtractive machining techniques, this material class has conquered the market and satisfied the patients’ needs for a long-lasting, excellent, and metal-free alternative for single tooth replacements and even smaller bridgework. Despite the popularity, not much is known about the material chemistry, microstructure and terminal behaviour. Methods: This article combines a set of own experimental data with extensive review of data from literature and other resources. Starting at manufacturer claims on unique selling propositions, properties, and microstructural features, the aim is to validate those claims, based on glass science. Deep knowledge is mandatory for understanding the microstructure evolution during the glass ceramic process. Results: Fundamental glass characteristics have been addressed, leading to formation of time-temperature-transformation (TTT) diagrams, which are the basis for kinetic description of the glass ceramic process. Nucleation and crystallization kinetics are outlined in this contribution as well as analytical methods to describe the crystalline fraction and composition qualitatively and quantitatively. In relation to microstructure, the mechanical performance of lithium silicate-based glass ceramics has been investigated with focus on fracture strength versus fracture toughness as relevant clinical predictors. Conclusion: Fracture toughness has been found to be a stronger link to initially outlined manufacturer claims, and to more precisely match ISO recommendations for clinical indications.
CRIS-Team Scopus Importer:2024-04-12
Keywords: Clinical indication; Crystallization; Flexural strength; Fracture toughness; Glass ceramic; Lithium silicate; Nucleation; Residual stress

Glendonite-bearing concretions from the upper Pliensbachian (Lower Jurassic) of South Germany: indicators for a massive cooling in the European epicontinental sea - Merkel, Anna; Munnecke, Axel (Facies, 2023)
The Pliensbachian–Toarcian transition was characterised by a drastic turnover from a cool climate to a period of rapid global warming. While the warming associated with the Early Toarcian Oceanic Anoxic Event is rather well-studied, the cause, intensity and extent of the preceding cooling in the late Pliensbachian are still discussed. Occurrences of glendonite play an important role in this debate, since glendonite is a pseudomorph after the cryophilic carbonate mineral ikaite. This study describes the first glendonite-bearing carbonate concretions from South Germany (Buttenheim clay pit, northern Franconian Alb), which represent the southernmost glendonite occurrence in the late Pliensbachian documented so far. Based on petrographical and sedimentological investigations as well as stable isotope analyses it is concluded that a low temperature was the main factor for ikaite formation in the studied section, suggesting that the late Pliensbachian cooling had a more far-reaching impact on the temperature of the European epicontinental sea than previously assumed. To explain the low temperatures required for ikaite precipitation, a model for the sea-ice driven formation of cold bottom-water masses on the continental shelf is proposed. The occurrence of several layers containing reworked hiatus concretions in the studied outcrop is interpreted as the result of recurrent sea-level falls caused by multiple glacial pulses characterising the overall cool climate in the late Pliensbachian.
CRIS-Team Scopus Importer:2023-07-07
Keywords: Glaciation; Glendonite; Hiatus concretions; Late Pliensbachian climate; Stable isotopes

Global change in the Late Devonian: modelling the Frasnian-Famennian short-term carbon isotope excursions - Joachimski, Michael; Goddéris, Yves (Palaeogeography, Palaeoclimatology, Palaeoecology, 2004)
A model of the global biogeochemical cycles coupled to a energy-balance climate model (the COMBINE model) is used to identify the causes of two large δ13C value excursions across the Frasnian-Famennian (F-F) boundary. We test a scenario that links the sea-level rise to stratification of the Proto-Tethys ocean through the formation of warm saline deep waters in extended epicontinental seas. Even though this scenario can produce dysoxia below 100 m depth, it fails to increase the global burial flux of organic carbon and thus seawater δ13C values, since stratification of the ocean leads to decreased productivity in surface waters. Several scenarios postulating a continental origin of the perturbations in the Late Devonian biogeochemical cycles are then tested. We found that weathering of platform carbonates exposed during the Early Famennian sea-level fall can account for a maximum positive shift in δ13C value of +0.7‰ at the end of the sea-level fall episode. Another +1.0‰ increase in δ 13C might originate from rapid spreading of vascular land plants near the F-F boundary, postulating that higher plants globally increased the weatherability of continental surface, and that colonized continental area increased by 30% across the F-F boundary. Finally, the δ13C excursion observed at the base of Upper rhenana Zone and the rapid increase of the carbon isotope ratios at the F-F boundary require an increase of phosphorus delivery to the ocean by 40%, coeval with the sea-level rises. Once the calculated δ13C values are in agreement with the measured data, the COMBINE model calculates a decrease in atmospheric pCO2 from pre-perturbation 2925 ppmv in the Lower rhenana conodont Zone to 1560 ppmv in the Upper triangularis Zone. This decrease in pCO2 is due to the increase in burial of organic matter during the Kellwasser events, and increased continental weatherability triggered by the spreading of continental vascular plants. These changes occur within 4 million years. The corresponding global climatic cooling reaches 4.4°C at the pole, and 2.1°C at the equator. © 2003 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2004.nat.dgeo.IGM.LG.global
Keywords: Carbon dioxide; Famennian; Frasnian; Isotope ratios; Modelling; Seawater

Global endemics-area relationships of vascular plants - Hobohm, Carsten; Janišová, Monika; Steinbauer, Manuel; Landi, Sara; Field, Richard; Vanderplank, Sula; Beierkuhnlein, Carl; Grytnes, John Arvid; Vetaas, Ole Reidar; Fidelis, Alessandra; de Nascimento, Lea; Clark, Vincent Ralph; et al. (Perspectives in Ecology and Conservation, 2019)
Endemics–Area Relationships (EARs)are fundamental in theoretical and applied biogeography for understanding distribution patterns and promoting biodiversity conservation. However, calculating EARs for vascular plant species from existing data is problematic because of biased knowledge of endemic species distributions and differences between taxonomies. We aimed to overcome these challenges by developing a new standardized global dataset based on expert knowledge to produce a set of global EARs. We developed a nested circle design, with grain sizes of 10 4 , 10 5 , 10 6 , 10 7 , and 10 8 km 2 , respectively, and a global distribution of plots based on a stratified random scheme. The number of vascular plant species endemic to each circle was then estimated independently by five experts randomly chosen from a pool of 23, as both a minimum and a maximum value (lower and upper bounds of the estimation), taking into account the limitations of current knowledge and varied species concepts in existing taxonomies. This procedure resulted in a dataset of 3000 expert estimates. Based on the data, we produced three global EARs for endemic species richness using minimum, maximum and average estimates. As a validation, we used all three models to extrapolate to the entire world, producing estimates of 284,493 (minimum), 398,364 (maximum)and 312,243 (average)vascular plant species. These figures conform to the range of taxonomists’ estimates. From the models, we calculated the average area needed to harbour a single endemic species as 12,875 km 2 (range 9675–20,529). The global vascular plant EARs we calculated represent the first standardized, quantitative expectations of plant endemism at any given scale (sampling unit size). These EARs allow us to provide a clear answer to a long-standing but elusive biogeographical question: how to assess whether any area on the surface of the Earth is rich or poor in endemics relative to the average.
CRIS-Team Scopus Importer:2019-05-02
Keywords: Distribution of land and sea; Expert knowledge; Global reference; Minimum and maximum estimates; Zero-endemic plots

Global imprint of climate change on marine life - Kießling, Wolfgang; Poloczanska, Elvira S.; Brown, Christopher J.; Sydeman, William J.; Kiessling, Wolfgang; Schoeman, David S.; Moore, Pippa J.; Brander, Keith; Bruno, John F.; Buckley, Lauren B.; Burrows, Michael T.; Duarte, Carlos M.; et al. (Nature Climate Change, 2013)
Past meta-analyses of the response of marine organisms to climate change have examined a limited range of locations, taxonomic groups and/or biological responses. This has precluded a robust overview of the effect of climate change in the global ocean. Here, we synthesized all available studies of the consistency of marine ecological observations with expectations under climate change. This yielded a meta-database of 1,735 marine biological responses for which either regional or global climate change was considered as a driver. Included were instances of marine taxa responding as expected, in a manner inconsistent with expectations, and taxa demonstrating no response. From this database, 81-83% of all observations for distribution, phenology, community composition, abundance, demography and calcification across taxa and ocean basins were consistent with the expected impacts of climate change. Of the species responding to climate change, rates of distribution shifts were, on average, consistent with those required to track ocean surface temperature changes. Conversely, we did not find a relationship between regional shifts in spring phenology and the seasonality of temperature. Rates of observed shifts in species' distributions and phenology are comparable to, or greater, than those for terrestrial systems. © 2013 Macmillan Publishers Limited. All rights reserved .
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LP.global

Global Island Monitoring Scheme (GIMS): a proposal for the long‐term coordinated survey and monitoring of native island forest biota - Borges, Paulo A. V.; Cardoso, Pedro; Kreft, Holger; Whittaker, Robert; Fattorini, Simone; Emerson, Brent C.; Gil, Artur; Gillespie, Rosemary G.; Matthews, Thomas J.; Santos, Ana M. C.; Steinbauer, Manuel; Thébaud, Christophe; et al. (Biodiversity and Conservation, 2018)
Islands harbour evolutionary and ecologically unique biota, which are currently disproportionately threatened by a multitude of anthropogenic factors, including habitat loss, invasive species and climate change. Native forests on oceanic islands are important refu- gia for endemic species, many of which are rare and highly threatened. Long-term monitor- ing schemes for those biota and ecosystems are urgently needed: (i) to provide quantitative baselines for detecting changes within island ecosystems, (ii) to evaluate the effectiveness of conservation and management actions, and (iii) to identify general ecological patterns and processes using multiple island systems as repeated ‘natural experiments’. In this contribu- tion, we call for a Global Island Monitoring Scheme (GIMS) for monitoring the remaining native island forests, using bryophytes, vascular plants, selected groups of arthropods and vertebrates as model taxa. As a basis for the GIMS, we also present new, optimized monitor- ing protocols for bryophytes and arthropods that were developed based on former standard- ized inventory protocols. Effective inventorying and monitoring of native island forests will require: (i) permanent plots covering diverse ecological gradients (e.g. elevation, age of ter- rain, anthropogenic disturbance); (ii) a multiple-taxa approach that is based on standardized and replicable protocols; (iii) a common set of indicator taxa and community properties that are indicative of native island forests’ welfare, building on, and harmonized with existing sampling and monitoring efforts; (iv) capacity building and training of local researchers, col- laboration and continuous dialogue with local stakeholders; and (v) long-term commitment by funding agencies to maintain a global network of native island forest monitoring plots.
Keywords: Beta-diversity; Ecological gradients; Forest monitoring protocols; Island conservation; Long-term monitoring; Sampling standardization

Global mass wasting during the Middle Ordovician: Meteoritic trigger or plate-tectonic environment? - Meinhold, Guido; Arslan, Arzu; Lehnert, Oliver; Stampfli, Gerard M. (Gondwana Research, 2011)
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LG.global

Global ocean conveyor lowers extinction risk in the deep sea - Henry, Lea-Anne; Frank, Norbert; Hebbeln, Dierk; Wienberg, Claudia; Robinson, Laura; van de Flierdt, Tina; Dahl, Mikael; Douarin, Mélanie; Morrison, Cheryl L.; López Correa, Matthias; Rogers, Alex D.; Ruckelshausen, Mario; et al. (Deep-Sea Research, 2014)
General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth's largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium-thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6. kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500. km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea. © 2014 The Authors.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LP.global
Keywords: Atlantic meridional overturning circulation; Climate change; Connectivity; Deep sea; Extinction; Larval dispersal

Global Warming and Mass Extinctions Associated With Large Igneous Province Volcanism - Bond, David P. G.; Sun, Yadong (Large Igneous Provinces: A Driver of Global Environmental and Biotic Changes, 2021)
The coincidence of large igneous province (LIP) eruptions with at least three, if not all, of the Big Five biotic crises of the Phanerozoic implies that volcanism is a key driver of mass extinctions. Many LIP-induced extinction scenarios invoke global warming, caused primarily (but not exclusively) by greenhouse gases emitted at the site of LIP emplacement and by contact metamorphism of carbon-rich host rocks. Here we explore (1) the climate-changing products of volcanism including sulfur dioxide (SO2), carbon dioxide (CO2) and methane (CH4) from eruptions, contact metamorphism, and melting (dissociation) of gas hydrates; (2) their deadly effects, including marine anoxia and thermal stress; (3) increasingly sophisticated paleotemperature proxies (e.g., delta(1)(8)Oof shell material) through case studies of the best-known LIP-warming-extinction nexi; and (4) global warming through the lens of the putative Anthropocene extinction.
CRIS-Team WoS Importer:2022-12-02

Global warming generates predictable extinctions of warm- and cold-water marine benthic invertebrates via thermal habitat loss - Reddin, Carl J.; Aberhan, Martin; Raja, Nussaïbah Begum; Kocsis, Ádám (Global Change Biology, 2022)
Anthropogenic global warming is redistributing marine life and may threaten tropical benthic invertebrates with several potential extinction mechanisms. The net impact of climate change on geographical extinction risk nevertheless remains uncertain. Evidence of widespread climate-driven extinctions and of potentially unidentified mechanisms exists in the fossil record. We quantify organism extinction risk across thermal habitats, estimated by paleoclimate reconstructions, over the past 300 million years. Extinction patterns at seven known events of rapid global warming (hyperthermals) differ significantly from typical patterns, resembling those driven by global geometry under simulated global warming. As isotherms move poleward with warming, the interaction between the geometry of the globe and the temperature-latitude relationship causes an uneven loss of thermal habitat and a bimodal latitudinal distribution of extinctions. Genera with thermal optima warmer than similar to 21 degrees C show raised extinction odds, while extinction odds continually increase for genera with optima below similar to 11 degrees C. Genera preferring intermediate temperatures generally have no additional extinction risk during hyperthermals, except under extreme conditions as the end-Permian mass extinction. Widespread present-day climate-driven range shifts indicate that occupancy loss is already underway. Given the most-likely projections of modern warming, our model, validated by seven past hyperthermal events, indicates that sustained warming has the potential to annihilate cold-water habitat and its endemic species completely within centuries.
CRIS-Team WoS Importer:2022-07-29

Global warming leads to Early Triassic nutrient stress across northern Pangea - Grasby, Stephen E.; Knies, Jochen; Beauchamp, Benoit; Bond, David P. G.; Wignall, Paul; Sun, Yadong (Geological Society of America Bulletin, 2020)
The largest extinction in Earth history, in the latest Permian, was followed throughout most of the Early Triassic by a prolonged period of ecologic recovery. What factors delayed biotic recovery are still under debate and partly revolve around impacts of global warming on primary marine productivity. We examined N isotope records from the Festningen section on Spitsbergen, Arctic Norway, to examine changes in nutrient availability through the Early to Middle Triassic along the northern margin of Pangea. Our results show progressive decline in N availability throughout the Griesbachian, leading to severe nutrient limitations through the remainder of the Early Triassic, until returning to a highly productive continental margin in Middle Triassic time. These results are consistent with other studies from northern and western Pangea and thus show regional nutrient limitations occurred in what should have been the main zone of marine primary productivity. Such nutrient limitation likely stressed primary production and consequently contributed to prolonged marine recovery. We suggest this was driven by high ocean temperatures depressing the marine nutricline.
CRIS-Team WoS Importer:2020-05-22

Global Water Balance - Barth, Johannes; et al. (Massachusetts Institute of Technology and Frankfurt Institute for Advanced Studies, 2010)

Gorongosa by the sea: First Miocene fossil sites from the Urema Rift, central Mozambique, and their coastal paleoenvironmental and paleoecological contexts - Habermann, Jörg; Alberti, Matthias; Aldeias, Vera; Alemseged, Zeresenay; Archer, Will; Bamford, Marion; Biro, Dora; Braun, David R.; Capelli, Cristian; Cunha, Eugenia; Da Silva, Maria Ferreira; Luedecke, Tina; et al. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2019)
The East African Rift System (EARS) has played a central role in our understanding of human origins and vertebrate evolution in the late Cenozoic of Africa. However, the distribution of fossil sites along the rift is highly biased towards its northern extent, and the types of paleoenvironments are primarily restricted to fluvial and lacustrine settings. Here we report the discovery of the first fossil sites from the Urema Rift at Gorongosa National Park (central Mozambique) at the southern end of the EARS, and reconstruct environmental contexts of the fossils. In situ and surface fossils from the lower member of the Mazamba Formation, estimated to be of Miocene age, comprise mammals, reptiles, fishes, invertebrates, palms, and dicot trees. Fossil and geological evidence indicates a coastal-plain paleoenvironmental mosaic of riverine forest/woodland and estuarine habitats that represent the first coastal biomes identified in the Neogene EARS context. Receiving continental sediment from source terranes west of today's Urema Graben, estuarine sequences accumulated prior to rifting as compound incised-valley fills on a low-gradient coastal plain following transgression. Modern environmental analogues are extremely productive habitats for marine and terrestrial fauna, including primates. Thus, our discoveries raise the possibility that the Miocene coastal landscapes of Gorongosa were ecologically-favorable habitats for primates, providing relatively stable maritime climate and ecosystem conditions, year-round freshwater availability, and food both from terrestrial and marine sources. The emerging fossil record from Gorongosa is beginning to fill an important gap in the paleobiogeography of Africa as no fossil sites of Neogene age have previously been reported from the southernmost part of the EARS. Furthermore, this unique window into past continental-margin ecosystems of central Mozambique may allow us to test key paleobiogeographic hypotheses during critical periods of primate evolution.
CRIS-Team Scopus Importer:2019-07-30
Keywords: Continental margin; Depositional environments; Eastern Africa; Landscape reconstruction; Paleontology; Primate behavioral ecology

Gradual onset of anoxia acros the Permian-Triassic boundary in Svalbard, Norway. - Dusitra, Anna; Wignall, Paul; Blomeier, Dirk; Joachimski, Michael; Hartkopf-Fröder, Christoph; Bond, David (Palaeogeography, Palaeoclimatology, Palaeoecology, 2013)
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LG.gradua

Gradual warming prior to the end-Permian mass extinction - Gliwa, Jana; Wiedenbeck, Michael; Schobben, Martin; Ullmann, Clemenz; Kießling, Wolfgang; Ghaderi, Abbas; Struck, Ulrich; Korn, Dieter (Palaeontology, 2022)
The biggest known mass extinction in the history of animal life occurred at the Permian-Triassic boundary and has often been linked to global warming. Previous studies have suggested that a geologically rapid (<40 kyr) temperature increase of more than 10 degrees C occurred simultaneously with the main extinction pulse. This hypothesis is challenged by geochemical and palaeontological data indicating profound environmental perturbations and a temperature rise prior to the main extinction. Using secondary ion mass spectrometry (SIMS), we measured oxygen isotope ratios from Changhsingian (late Permian) ostracods of north-western Iran. Our data show that ambient seawater temperature began to rise at least 300 kyr prior to the main extinction event. Gradual warming by approximately 12 degrees C was probably responsible for initial environmental degradation that eventually culminated in the global end-Permian mass extinction.
CRIS-Team WoS Importer:2022-09-16

Graptoloid evolutionary rates track ordovician-Silurian global climate change - Cooper, Roger A.; Munnecke, Axel; Sadler, Peter M.; Crampton, James S. (Geological Magazine, 2014)
Graptoloid evolutionary dynamics show a marked contrast from the Ordovician to the Silurian. Subdued extinction and origination rates during the Ordovician give way, during the late Katian, to rates that were highly volatile and of higher mean value through the Silurian, reflecting the significantly shorter lifespan of Silurian species. These patterns are revealed in high-resolution rate curves derived from the CONOP (constrained optimization) scaled and calibrated global composite sequence of 2094 graptoloid species. The end-Ordovician mass depletion was driven primarily by an elevated extinction rate which lasted for c. 1.2 Ma with two main spikes during the Hirnantian. The early Silurian recovery, although initiated by a peak in origination rate, was maintained by a complex interplay of origination and extinction rates, with both rates rising and falling sharply. The global δC curve echoes the graptoloid evolutionary rates pattern; the prominent and well-known positive isotope excursions during the Late Ordovician and Silurian lie on or close to times of sharp decline in graptoloid species richness, commonly associated with extinction rate spikes. The graptoloid and isotope data point to a relatively steady marine environment in the Ordovician with mainly background extinction rates, changing during the Katian to a more volatile climatic regime that prevailed through the Silurian, with several sharp extinction episodes triggered by environmental crises. The correlation of graptoloid species diversity with isotopic ratios was positive in the Ordovician and negative in the Silurian, suggesting different causal linkages. Throughout the history of the graptoloid clade all major depletions in species richness except for one were caused by elevated extinction rate rather than decreased origination rate. © Cambridge University Press 201
Keywords: climatic forcing; diversity; extinction; plankton

Grasping the Lithium hype: Insights into modern dental Lithium Silicate glass-ceramics - Lubauer, Julia; Belli, Renan; Peterlik, Herwig; Hurle, Katrin; Lohbauer, Ulrich (Dental Materials, 2022)
Objectives: Lithium-based glass-ceramics are currently dominating the landscape of dental restorative ceramic materials, with new products taking the market by storm in the last years. Though, the difference among all these new and old products is not readily accessible for the practitioner, who faces the dilemma of reaching a blind choice or trusting manufacturers' marketing brochures. To add confusion, new compositions tend to wear material terminologies inherited from vanguard dental lithium disilicates, disregarding accuracy. Here we aim to characterize such materials for their microstructure, crystalline fraction, glass chemistry and mechanical properties. Methods: Eleven commercial dental lithium-based glass ceramics were evaluated: IPS e.max (R) CAD, IPS e.max (R) Press, Celtra (R) Duo, Suprinity (R) PC, InitialTM LiSi Press, InitialTM LiSi Block, Amber (R) Mill, Amber (R) Press, N!CE (R), Obsidian (R) and CEREC TesseraTM. The chemical composition of their base glasses was measured by X-Ray Fluorescence Spectroscopy (XRF) and Inductive Coupled Plasma Optical Emission Spectroscopy (ICPOES), as well as the composition of their residual glass by subtracting the oxides bound in the crystallized fraction, characterized by X-Ray Diffraction (XRD) and Rietveld refinement, and quantified accurately using the G-factor method (QXRD). The crystallization behavior is revealed by differential scanning calorimetry (DSC) curves. Elastic constants are provided from Resonant Ultrasound Spectroscopy (RUS) and the fracture toughness measured by the Ball-on-Three-Balls method (B3B- K Ic). The microstructure is revealed by fieldemission scanning electron microscopy (FE-SEM). Results: The base glasses showed a wide range of SiO2 /Li2O ratios, from 1.5 to 3.0, with the degree of depolymerization dropping from 1/2 to 2/3 of the initial connectivity. Materials contained Li2SiO3+Li3PO4, Li2SiO3+Li3PO4+Li2Si2O5, Li2Si2O5+Li3PO4+ Cristobalite and/or Quartz and Li2Si2O5+Li3 PO4+LiAlSi2O6, in crystallinity degrees from 45 to 80 vol%. Crystalline phases could be traced to their crystallization peaks on the DSC curves. Pressable materials and IPS e.max (R) CAD were the only material showing micrometric phases, with N!CE (R) and InitialTM LiSi Block showing solely nanometric crystals, with the rest presenting a mixture of submicrometric and nanometric particles. Fracture toughness from 1.45 to 2.30 MPa root m were measured, with the linear correlation to crystalline fraction breaking down for submicrometric and nanometric crystal phases. Significance: Dental lithium-based silicate glass-ceramics cannot be all put in the same bag, as differences exist in chemical composition, microstructure, crystallinity and mechanical properties. Pressable materials still perform better mechanically than CAM/CAM blocks, which loose resistance to fracture when crystal phases enter the submicrometric and na-nometric range (c) 2021 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.
CRIS-Team WoS Importer:2022-03-04

GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands - Dengler, Juergen; Wagner, Viktoria; Dembicz, Iwona; Garcia-Mijangos, Itziar; Naqinezhad, Alireza; Boch, Steffen; Chiarucci, Alessandro; Conradi, Timo; Filibeck, Goffredo; Guarino, Riccardo; Janisova, Monika; Steinbauer, Manuel; et al. (Phytocoenologia, 2018)
GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (relevés) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001; ... 1,000 m ) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetation-plot databases, such as the European Vegetation Archive (EVA) and the global database “sPlot”. Its main aim is to facilitate studies on the scale- and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Coordinating Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board

Gravitational reactivation of a pre-existing post-caledonian fault system: The deep-seated gravitational slope deformation at Middagstinden, Western Norway - Schleier, Markus; Hermanns, Reginald L.; Krieger, Ingvar; Oppikofer, Thierry; Eiken, Trond; Ronning, Jan Steinar; Rohn, Joachim (Norwegian Journal of Geology, 2016)
Keywords: Berill fault; DSGSD; Geomorphology; Pseudotectonics; Structural geology

Groundwater connections under a barrier beach: a case study in the Venice Lagoon - Rapaglia, John; Di Sipio, Eloisa; Bokuniewicz, Henry; Zuppi, Gian Maria; Zaggia, Luca; Galgaro, Antonio; Beck, Aaron (Continental Shelf Research, 2010)
Keywords: Groundwater transport; Barrier islands; Seepage meter; Storm surgebarriers; Venice Lagoon

Groundwater data improve modelling of headwater stream CO2 outgassing with a stable DIC isotope approach - Marx, Anne; Conrad, Markus; Aizinger, Vadym; Prechtel, Alexander; van Geldern, Robert; Barth, Johannes (Biogeosciences, 2018)
A large portion of terrestrially derived carbon outgasses as carbon dioxide (CO2) from streams and rivers to the atmosphere. Particularly, the amount of CO2 outgassing from small headwater streams is highly uncertain. Conservative estimates suggest that they contribute 36 % (i.e. 0.93 petagrams (Pg) C yr−1) of total CO2 outgassing from all fluvial ecosystems on the globe. In this study, stream pCO2, dissolved inorganic carbon (DIC), and δ13CDIC data were used to determine CO2 outgassing from an acidic headwater stream in the Uhlířská catchment (Czech Republic). This stream drains a catchment with silicate bedrock. The applied stable isotope model is based on the principle that the 13C ∕ 12C ratio of its sources and the intensity of CO2 outgassing control the isotope ratio of DIC in stream water. It avoids the use of the gas transfer velocity parameter (k), which is highly variable and mostly difficult to constrain. Model results indicate that CO2 outgassing contributed more than 80 % to the annual stream inorganic carbon loss in the Uhlířská catchment. This translated to a CO2 outgassing rate from the stream of 34.9 kg C m−2 yr−1 when normalised to the stream surface area. Large temporal variations with maximum values shortly before spring snowmelt and in summer emphasise the need for investigations at higher temporal resolution. We improved the model uncertainty by incorporating groundwater data to better constrain the isotope compositions of initial DIC. Due to the large global abundance of acidic, humic-rich headwaters, we underline the importance of this integral approach for global applications.<br

Groundwater recharge sites and pollution sources in the wine-producing Guadalupe Valley (Mexico): Restrictions and mixing prior to transfer of reclaimed water from the US-México border - Daesslé, L. W.; Andrade-Tafoya, P. D.; Lafarga-Moreno, J.; Mahlknecht, J.; van Geldern, Robert; Beramendi-Orosco, L. E.; Barth, Johannes (Science of the Total Environment, 2020)
Rapid depletion of aquifers in semiarid and arid regions threatens water security. This holds true especially in emerging countries where insufficient knowledge about aquifer systems precludes the implementation of advanced management measures, such as managed aquifer recharge. This study deals with the generation of baseline knowledge for the assessment of aquifers in arid and semiarid regions where artificial recharge with reclaimed water gains increasing impetus. The Guadalupe aquifer in Baja California provides water to 57% of the Mexican wine industry. Recent plans foresee a partial replenishment of its depleted groundwater reserves by transferring treated waste water from the Mexico-USA border for irrigation. The aquifer demonstrated to have a rapid response by rising the water table of about +20 m in relation to natural recharge under an intense rainfall period of 236 mm. Two predominant recharge sources were identified based on a geochemical multi-tracer approach: (a) water of modern age (<5 yr, >1.8 TU) and mixed water of recent-submodern age (3H 0.8–1.8 TU), and (b) sub-modern waters that were recharged before 1952 (3H < 0.5 TU). Water of the first type originate in the main Guadalupe stream, which has a more depleted average δ18O isotope value (−7.8‰) than average local rainwater (−2.0‰). The stream water initially has a Na-HCO3 composition and recharges the entire Calafia zone and most groundwater along the riverbed across the valley. Water of the second type is mostly derived from hill-slope groundwater that has a stable isotope composition of mixed local rainwater and a Na[sbnd]Cl composition. High total dissolved solids >2 g l−1 together with enriched NO3 − and Se concentrations characterize groundwater in the downstream the Porvenir zone. The geochemical age of this older, hill-slope groundwater suggests that its replenishment takes at least several decades when it becomes exhausted.
CRIS-Team Scopus Importer:2020-01-28
Keywords: Aquifer; Groundwater recharge; Mexico; Return flows; Stable isotopes; Tritium; Wastewater

Groundwater temperatures downstream from a large-scale geothermal collector system (LSC) in Bad Nauheim, Germany - Rammler, Mario; Bertermann, David (Grundwasser, 2025)
The impact of horizontal geothermal systems on groundwater temperature has not been studied in detail due to their generally shallow installation depth. However, interactions between very shallow geothermal systems and groundwater are expected, especially at short groundwater distances. In this study, the effects of a large-scale geothermal collector system (LSC) in Bad Nauheim (Hesse, Germany) on the downstream shallow groundwater were analysed. For this purpose, subsurface and groundwater temperatures were measured over a period of two years. The results showed that in the immediate downstream area, the maximum degree of cooling of the groundwater temperature was between 4.2 and 5.2 K with a minimum temperature of 5.2 °C. Consequently, the presence of a temperature plume was demonstrated, whereby a significant regeneration of the subsurface temperature in comparison to measured values within the LSC area was also observed.
CRIS-Team Scopus Importer:2025-02-14
Keywords: Groundwater monitoring; Groundwater temperature; Large-scale geothermal collector system (LSC); Temperature plume

Groundwater units and their potential for development at Nuremberg, Germany - Baier, Alfons; van Geldern, Robert; Loehr, Gisela; Subert, Hannah Lisa; Barth, Johannes (Grundwasser, 2016)

Growth allometry and dental topography in Upper Triassic conodonts support trophic differentiation and molar-like element function - Kelz, Valentin; Guenser, Pauline; Rigo, Manuel; Jarochowska, Emilia (Paleobiology, 2023)
Conodont elements have high rates of morphological evolution, but the drivers of this disparity are debated. Positive allometric relationships between dimensions of food-processing surfaces and entire P1 elements have been used to argue that these elements performed mechanical digestion. If involved in food processing, the surface of the element should grow at a rate proportional to the increase in energy requirements of the animal. This inference of function relies on the assumption that the energy requirements of the animal grew faster (≃ mass0.75) than the tooth area (≃ mass0.67). We reevaluate this assumption based on metabolic rates across animals and calculate the allometry in platform-bearing P1 elements of Late Triassic co-occurring taxa, Metapolygnathus communisti and Epigondolella rigoi, using 3D models of ontogenetic series. Positive allometry is found in platform and element dimensions in both species, supporting a grasping-tooth hypothesis, based on the assumption that metabolic rate in conodonts scaled with body mass similarly to that in fish and ectotherms. We also calculate the curvature of the P1 platform surface using the Dirichlet normal energy (DNE) as a proxy for diet. DNE values increase with body mass, supporting the assumption that conodont metabolic rates increased faster than mass0.67. We finally find that adults in both taxa differ in their food bases, which supports trophic diversification as an important driver of the remarkable disparity of conodont elements.
CRIS-Team Scopus Importer:2023-03-31

Growth and feeding ecology of coniform conodonts - Leonhard, Isabella; Shirley, Bryan; Murdock, Duncan J. E.; Repetski, John; Jarochowska, Emilia (PeerJ, 2021)
Conodonts were the first vertebrates to develop mineralized dental tools, known as elements. Recent research suggests that conodonts were macrophagous predators and/or scavengers but we do not know how this feeding habit emerged in the earliest coniform conodonts, since most studies focus on the derived, 'complex' conodonts. Previous modelling of element position and mechanical properties indicate they were capable of food processing. A direct test would be provided through evidence of in vivo element crown tissue damage or through in vivo incorporated chemical proxies for a shift in their trophic position during ontogeny. Here we focus on coniform elements from two conodont taxa, the phylogenetically primitive Proconodontus muelleri Miller, 1969 from the late Cambrian and the more derived Panderodus equicostatus Rhodes, 1954 from the Silurian. Proposing that this extremely small sample is, however, representative for these taxa, we aim to describe in detail the growth of an element from each of these taxa in order to the test the following hypotheses: (1) Panderodus and Proconodontus processed hard food, which led to damage of their elements consistent with prey capture function; and (2) both genera shifted towards higher trophic levels during ontogeny. We employed backscatter electron (BSE) imaging, energy-dispersive X-ray spectroscopy (EDX) and synchrotron radiation X-ray tomographic microscopy (SRXTM) to identify growth increments, wear and damage surfaces, and the Sr/Ca ratio in bioapatite as a proxy for the trophic position. Using these data, we can identify whether they exhibit determinate or indeterminate growth and whether both species followed linear or allometric growth dynamics. Growth increments (27 in Pa. equicostatus and 58 in Pr. muelleri) were formed in bundles of 4-7 increments in Pa. equicostatus and 7-9 in Pr. muelleri. We interpret the bundles as analogous to Retzius periodicity in vertebrate teeth. Based on applied optimal resource allocation models, internal periodicity might explain indeterminate growth in both species. They also allow us to interpret the almost linear growth of both individuals as an indicator that there was no size-dependent increase in mortality in the ecosystems where they lived e.g., as would be the case in the presence of larger predators. Our findings show that periodic growth was present in early conodonts and preceded tissue repair in response to wear and damage. We found no microwear and the Sr/Ca ratio, and therefore the trophic position, did not change substantially during the lifetimes of either individual. Trophic ecology of coniform conodonts differed from the predatory and/or scavenger lifestyle documented for "complex" conodonts. We propose that conodonts adapted their life histories to top-down controlled ecosystems during the Nekton Revolution.
CRIS-Team WoS Importer:2021-12-31

Growth interruptions in Arctic rhodoliths correspond to water depth and rhodolith morphology - Schlüter, Moritz; Pyko, Ines Anna; Wisshak, Max; Schulbert, Christian; Teichert, Sebastian (Minerals, 2021)
Coralline algae that form rhodoliths are widespread globally and their skeletal growth patterns have been used as (paleo-) environmental proxies in a variety of studies. However, growth interruptions (hiati) within their calcareous skeletons are regarded as problematic in this context. Here we investigated how hiati in the growth of Arctic rhodoliths from the Svalbard archipelago correspond to their environment and morphology. Using X-ray micro-computed tomography and stepwise model selections, we found that rhodoliths from deeper waters are subject to more frequent hiatus formation. In addition, rhodoliths with a higher sphericity (i.e., roundness) are less often affected by such growth interruptions. We conclude that these correlations are mainly regulated by hydrodynamics, because, in deeper waters, rhodoliths are not turned frequently enough to prevent a dieback of coralline algal thalli forming on the underside of the rhodolith. In this coherence, spheroidal rhodoliths are turned more easily, therefore shortening the amount of time between turnover events. Moreover, the incidence of light is more advantageous in shallower waters where rhodoliths exhibit a greater share of their surface to diffused ambient light, thus enabling thallus growth also on the down-facing surface of the rhodoliths. In consequence, information on the frequency of hiatus formation combined with rhodolith morphology might serve as a valuable proxy for (paleo-)environmental reconstructions in respect to light availability and the hydrodynamic regim
Keywords: coralline algae; environmental proxies; growth increments; polar carbonates; Svalbard; X-ray micro-computed tomography

Growth of high-quality homoepitaxial diamond films by HF-CVD - Stammler, Markus; Eisenbeiß, Henrick; Ristein, Jürgen; Neubauer, Jürgen; Göbbels, Matthias; Ley, Lothar; Ristein, Jürgen; Ley, Lothar (Diamond and Related Materials, 2002)
Defined growth of high-quality crystalline diamond films is necessary for manufacturing of electronic devices. Several groups have already worked on this topic and the main challenges remaining are the suppression of crystalline defects, the reduction of impurities and higher growth rates. High-quality homoepitaxial diamond films were produced in a hot filament chemical vapor deposition (HF-CVD) system with and without addition of nitrogen to the gas phase. Substrates were (100)-oriented synthetic Ib diamonds (Sumitomo) with a maximum misorientation angle of 0.3° as determined by X-ray diffraction. By adjusting the α parameter independently to a value close to two using polycrystalline diamond films on silicon growth rates of up to 500 nm/h could be achieved while simultaneously keeping the density of unepitaxial crystallites below 10 cm-2. The surface roughness (RMS) was below 1 nm in a 1 × 1-μm2 area. Impurities were studied by photoluminescence and cathodoluminescence spectroscopy. For the films deposited without intentional nitrogen addition, nitrogen-related impurities could only be detected by low temperature photoluminescence indicating a very low concentration. At 1.68 eV we observed the signature of the Si-vacancy complex probably caused by evaporation of Si from the tungsten filament. © 2002 Elsevier Science B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.LM.growth
Keywords: Diamond growth and characterization; HF-CVD; Homoepitaxy; Luminescene

Growth of the upper crust in intra-oceanic island arcs by intrusion of basaltic magmas: the case of the Koloula Igneous Complex, Guadalcanal, Solomon Islands (SW Pacific) - Sotiriou, Paul; Haase, Karsten; Schneider, Kathrin; Grosche, Anna; Nöbel, Kristina; Chivas, Allan R. (Contributions To Mineralogy and Petrology, 2022)
The Pleistocene (2.2–1.5 Ma) Koloula Igneous Complex (KIC) on Guadalcanal in the Solomon island arc consists of a low-K calc-alkaline sequence of ultramafic to felsic plutonic rocks. We present whole-rock major and trace element and Sr–Nd-Pb isotope data, as well as mineral compositions that record the magmatic evolution of the complex. The intrusive sequence is grouped into two cycles, Cycle 1 and 2, comprising gabbroic or dioritic to granodioritic rocks. The major and trace element data of each cycle forms a single calc-alkaline fractional crystallisation trend. The distinct radiogenic isotope and incompatible element compositions of the Cycle 1 and 2 intrusions imply slightly different mantle sources. The KIC formed by shallow (0.1 GPa) fractional crystallisation of mantle-derived Al-rich basaltic parental magmas (6–8 wt.% MgO) that were formed by deeper-level (0.7 GPa) fractionation of olivine and pyroxene from Mg-rich ( 11 wt.% MgO) primary magmas in the Solomon intra-oceanic island arc. Olivine, clinopyroxene, plagioclase, amphibole, biotite, apatite, and Fe–Ti oxides fractionated from the KIC’s high-Al basaltic parental magmas to form calc-alkaline magmas. Liquid line of descent trends calculated using mass balance calculations closely match major element trends observed in the KIC data. The KIC crystallised at shallow, upper crustal depths of 2.0–3.0 km in 20 km-thick island arc crust. This complex is typical of other Cenozoic calc-alkaline ultramafic to felsic plutons in Pacific intra-oceanic island arcs in terms of field relationships, petrology, mineral chemistry and whole-rock geochemistry. Hornblende fractionation played a significant role in the formation of the calc-alkaline felsic plutonic rocks in these Cenozoic arc plutons, causing an enrichment of SiO2 and light rare earth elements. These plutons represent the fossil magma systems of arc volcanoes; thus, the upper arc crust is probably generated by migration of magmatic centres.
CRIS-Team Scopus Importer:2022-11-25
Keywords: Basaltic magmas; Fractional crystallisation; Island arcs; Koloula; Plutonic; Solomon Islands

Growth trajectories of some major ammonoid sub-clades revealed by serial grinding tomography data - Naglik, Carole; Monnet, Claude; Götz, Stefan; Kolb, Christian; de Baets, Kenneth; Tajika, Amane; Klug, Christian (Lethaia, 2015)
Molluscs such as ammonoids record their growth in their accretionary shells, making them ideal for the study of evolutionary changes in ontogeny through time. Standard methods usually focus on two-dimensional data and do not quantify empirical changes in shell and chamber volumes through ontogeny, which can possibly be important to disentangle phylogeny, interspecific variation and palaeobiology of these extinct cephalopods. Tomographic and computational methods offer the opportunity to empirically study volumetric changes in shell and chamber volumes through ontogeny of major ammonoid sub-clades in three dimensions (3-D). Here, we document (1) the growth of chamber and septal volumes through ontogeny and (2) differences in ontogenetic changes between species from each of three major sub-clades of Palaeozoic ammonoids throughout their early phylogeny. The data used are three-dimensional reconstructions of specimens that have been subjected to grinding tomography. The following species were studied: the agoniatitid Fidelites clariondi and anarcestid Diallagites lenticulifer (Middle Devonian) and the Early Carboniferous goniatitid Goniatites multiliratus. Chamber and septum volumes were plotted against the septum number and the shell diameter (proxies for growth) in the three species; although differences are small, the trajectories are more similar among the most derived Diallagites and Goniatites compared with the more widely umbilicate Fidelites. Our comparisons show a good correlation between the 3-D and the 2-D measurements. In all three species, both volumes follow exponential trends with deviations in very early ontogeny (resolution artefacts) and near maturity (mature modifications in shell growth). Additionally, we analyse the intraspecific differences in the volume data between two specimens of Normannites (Middle Jurassic).
Keywords: 3-D reconstruction; allometry; ammonoidea; ontogeny; palaeozoic; tomography; volumes

Grundsätzliche Überlegungen zur Edition des Bestandes an Münzen der FAU als frei zugängliche Datenbank im WWW - Boß, Martin; Murgan, Andreas; Bauer, Frank; Göbbels, Matthias (Magazin für digitale Editionswissenschaften, 2017)
Keywords: Edition; Numismatik; Datenbank

Grundwasser in Nürnberg: Wichtige Einheiten und deren Nutzbarkeit - Baier, Alfons; van Geldern, Robert; Loehr, Gisela; Subert, Hannah Lisa; Barth, Johannes (Grundwasser, 2016)
UnivIS-Import:2018-09-05:Pub.2016.nat.dgeo.IGM.LAG.grundw
Keywords: Groundwater; Geothermal energy; Palaeo-valleys; Stable isotopes; Keuper stratigraphy and hydrogeology

Gypsum evaporites in a patch reef of the upper Slite Group in the Silurian (Wenlock) of Gotland, Sweden - Färber, Claudia; Munnecke, Axel (GFF, 2014)
Calcite pseudomorphs after gypsum are observed in a patch reef in the upper Slite Group (Wenlock) on north-east (NE) Gotland (Sweden). The idiomorphic pseudomorphs occur (a) in silt-sized carbonate sediment in former moldic pores, (b) in the micritic matrix of bioclastic rudstones and (c) in the thrombolitic matrix of the reef. The dominance of stenohaline organisms in the reef indicates normal marine salinities during reef growth. The development of evaporitic conditions and the formation of evaporitic minerals therefore postdate reef growth. The authigenic gypsum crystals are interpreted to be formed by downward percolating hypersaline brines which existed on an extremely shallow carbonate platform during the early Homerian (latest Cyrtograptus lundgreni graptolite Zone) regression. © 2013 © 2013 Taylor & Franci
Keywords: evaporites; Gotland; gypsum; reef; Silurian; Slite

H2O in omphacite of quartz and coesite eclogite from Erzgebirge and Fichtelgebirge, Germany - Gose, Jürgen; Schmädicke, Esther (Journal of Metamorphic Geology, 2021)
Major and trace elements in omphacite, including hydrogen, were determined in eclogites from two Variscan basement complexes in Germany: Erzgebirge (EG) and Fichtelgebirge (FG). Erzgebirge eclogite is derived from three units, showing different peak pressure (P) and temperature (T) conditions (Unit 1: 840-920 degrees C/>= 30 kbar, Unit 2: 670-730 degrees C/24-26 kbar, Unit 3: 600-650 degrees C/20-22 kbar). The peak conditions of FG eclogite (690-750 degrees C/25-28 kbar) resemble those of EG Unit 2. Coesite eclogite occurs in EG Unit 1, and quartz eclogite in all other units. Omphacite from all samples shows four infrared (IR) absorption bands. Two prominent, sharp bands occur at 3,455 +/- 10 cm(-1) (band II) and 3,522 +/- 10 cm(-1) (band III). Band II is usually more prominent than band III, except for few samples with low jadeite content. A further, broad band is centred between 3,270 and 3,370 cm(-1) (band I) and a fourth, minor band at 3,611-3,635 cm(-1) (band IV). Bands II and III are due to hydrogen bound as structural OH- ions in omphacite. In most cases, this also applies to band IV. However, some spectra with extremely large type IV bands reflect phengite inclusions. The ambiguous band I may be due to different H2O species (molecular water, structural OH, and water in phengite). Omphacite of quartz eclogite has lower contents of TiO2, Zr, Hf, and REE, compared with that from coesite eclogite. By contrast, omphacite in quartz eclogite from both EG (H2O sample averages: 465-852 ppm) and FG (546-1,089 ppm) contains the same amount of structural OH (concentrations given in wt.-ppm H2O) as omphacite in coesite eclogite (492-1,140 ppm). The obtained difference in the garnet-omphacite H2O partition coefficient between quartz (0.01-0.03) and coesite eclogite (0.08-0.11) results from different H2O contents in garnet (coesite eclogite: 50-150 ppm; quartz eclogite: <2-50 ppm; Gose & Schmadicke, 2018). The total content of structural OH in omphacite is unrelated to its major and trace element composition. However, treating the individual IR bands separately, a relation between OH and mineral composition is observed. The OH amount defined by band II is positively correlated to Ti and tetrahedral Al, and that of band III shows a positive correlation with Ca and a negative one with Na (and jadeite). Both the total OH content of omphacite and the partial contents deduced from individual IR bands are unrelated to PT conditions. This implies that omphacite incorporated its structural H2O mainly in the quartz stability field, presumably during initial omphacite growth. Conversely, most OH in garnet was derived from the final breakdown of the last remaining calcic amphibole close to or within the coesite stability field. Our data suggest that coesite eclogite is able to transport a significant amount of H2O (average 550 ppm, maximum 730 ppm), corresponding to that in 3-4 vol.% calcic amphibole, via subduction to depths beyond 100 km. However, the majority of water liberated by dehydration reactions during subduction, including the breakdown of 5-10 vol.% eclogite facies and >10 vol.% pre-eclogitic hydrous minerals, is not preserved in eclogite but liberated to the mantle wedge.
CRIS-Team WoS Importer:2021-12-24

Habitat characteristics and carbonate cycling of macrophyte-supported polar carbonate factories (Svalbard)) - Cruise No. MSM55 – June 11 – June 29, 2016 – Reykjavik (Iceland) – Longyearbyen (Norway) - Wisshak, Max; Bartholomä, Alexander; Beuck, Lydia; Büscher, Janina; Freiwald, André; Halfar, Jochen; Hetzinger, Steffen; van Heugten, Bart; Hissmann, Karen; Holler, Peter; Meyer, Neele; Neumann, Hermann; et al. (2017)

Habitat effects and sampling bias on Phanerozoic reef distribution - Kießling, Wolfgang (Facies, 2005)
Incomplete preservation, heterogeneous geographic sampling, uncertainties in palaeogeographic reconstructions and inconsistencies of reef definitions bias global reef patterns observed in the geological record. This sampling bias is added to a biological habitat area effect, which is thought to be of paramount importance for modern reefs. To evaluate the importance of sampling bias of ancient reefs, I first tested the habitat area effect and sampling bias for modern tropical reefs and then evaluated these factors for pre-Pleistocene Phanerozoic reefs. Results suggest that habitat area, although significantly affecting Phanerozoic reef patterns, is considerably less important than sampling bias. Sampling bias is more controlled by socioeconomic factors than by geological processes such as subduction of oceanic crust or sea-level fluctuations. Reefs are more likely to be sampled in rich countries, irrespective of geological and ecological controls. The numeric and geographic distribution of reefs as currently recorded in the published literature is thus probably largely artifactual, which may explain the scarcity of significant correlations between reef distribution patterns and inferred physico-chemical controls. © Springer-Verlag 2005.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LP.habita

Hafnium-Neodymium isotope, trace element and U-Pb zircon age constraints on the petrogenesis of the 3.44–3.46 Ga Dwalile greenstone remnant, Ancient gneiss Complex, Swaziland - Hoffmann, J. Elis; Musese, Emmanuel; Kröner, Alfred; Schneider, Kathrin; Wong, Jean; Hofmann, Axel; Hegner, Ernst; Kasper, Haino Uwe; Tusch, Jonas; Münker, Carsten (Precambrian Research, 2020)
The geodynamic setting of the 3.44–3.46 Ga Dwalile greenstone remnant (DGR) of the Ancient Gneiss Complex (Swaziland) and its relationship to other Greenstone belts of similar age is investigated in this contribution. We present Hf-Nd isotope, major and trace element data for komatiites, komatiitic basalts, basalts, basaltic andesites as well as felsic volcanic and sedimentary rocks, all metamorphosed at amphibolite-facies grade. Major and trace element compositions of metabasalts and metakomatiites indicate crustal contamination. The best-preserved samples yield 176Lu-176Hf and 147Sm-143Nd isochron ages of ca. 3500 and 3460 Ma, respectively, in line with U-Pb zircon ages of interlayered felsic volcanic rocks of 3460 Ma. Isotope and trace element data for the metasedimentary rocks reveal a contribution of older crustal material with 3.53 Ga zircon grains. Together with >3.7 Ga inherited zircon grains in the Ngwane gneiss (NG) of the basement, this evidence supports a model of deposition of the Dwalile supracrustal rocks on or near older continental crust. Initial εHf and εNd values of the least contaminated DGR metabasalts and metakomatiites are similar to those of the contemporaneous Komati Formation komatiites and tholeiitic basalts, however, the trace element composition and slight correlations of initial εHf and εNd values with major and trace element parameters indicative for crustal contamination reveal differences in the basement of both units.
CRIS-Team Scopus Importer:2020-11-20
Keywords: Ancient Gneiss Complex; Archean; Dwalile; Felsic volcanic rocks; Komatiites; Swaziland

Harnessing stratigraphic bias at the section scale: Conodont diversity in the Homerian (Silurian) of the Midland Platform, England - Jarochowska, Emilia; Ray, David C.; Röstel, Philipp; Worton, Graham J.; Munnecke, Axel (Palaeontology, 2018)
Keywords: Conodonts; Diversity; Extinction; Mulde event; Sequence stratigraphy; Wenlock

Heating and cooling performance analysis of a ground source heat pump system in Southern Germany - Luo, Jin; Bayer, Manfred; Prieß, Anna; Wilkmann, Lucas; Xiang, Wei; Rohn, Joachim (Geothermics, 2015)
Keywords: Coefficient of performance (COP); Energy efficiency ratio (EER); Ground source heat pump (GSHP) system; System performance

Heat sources for mantle plumes. - Beier, Christoph; Rushmer, Tracy; Turner, Simon P. (Geochemistry Geophysics Geosystems, 2008)
Melting anomalies in the Earth's upper mantle have often been attributed to the presence of mantle plumes that may originate in the lower mantle, possibly from the core-mantle boundary. Globally, mantle plumes exhibit a large range in buoyancy flux that is proportional to their temperature and volume. Plumes with higher buoyancy fluxes should have higher temperatures and experience higher degrees of partial melting. This excess heat in mantle plumes could reflect either (1) an enrichment of the heat-producing elements (HPE: U, Th, K) in their mantle source leading to an increase of heat production by radioactive decay, (2) material transport from core to mantle (either advective or diffusive), or (3) conductive heat transport across the core-mantle boundary. The advective/diffusive transport of heat may result in a physical contribution of material from the core to the lower mantle. If core material is incorporated into the lower mantle, mantle plumes with a higher buoyancy flux should have higher core tracers, e.g., increased 186Os, 187Os, and Fe concentrations. Geophysical and dynamic modeling indicate that at least Afar, Easter, Hawaii, Louisville, and Samoa may all originate at the core-mantle boundary. These plumes encompass the whole range of known buoyancy fluxes from 0.9 Mg s-1 (Afar) to 8.7 Mg s-1 (Hawaii), providing evidence that the buoyancy flux is largely independent of other geophysical parameters. In an effort to explore whether the heat-producing elements are the cause of excess heat we looked for correlations between fractionation-corrected concentrations of the HPE and buoyancy flux. Our results suggest that there is no correlation between HPE concentrations and buoyancy flux (with and without an additional correction for variable degrees of partial melting). As anticipated, K, Th, and U are positively correlated with each other (e.g., Hawaii, Iceland, and Galapagos have significantly lower concentrations than, e.g., Tristan da Cunha, the Canary Islands, and the Azores). We also find no correlation between Fe and buoyancy flux. The apparent lack of correlations suggests that excess heat may be a result of conductive heat contribution from the core or from the adjacent boundary layer. Thus, the formation of mantle plumes along the core-mantle boundary may be largely controlled by distance of enriched material from the coremantle boundary. Copyright 2008 by the American Geophysical Union.
UnivIS-Import:2015-03-09:Pub.2008.nat.dgeo.IGM.legeo.heatso
Keywords: Core contribution; Core-mantle boundary; Heat producing elements; Heat production; Mantle heterogeneity; Mantle plumes

Heat transfer in quaternary deposits: how thermal conductivity is affected by moisture content - Di Sipio, Eloisa; Bertermann, David (Proceedings “Der Geothermiekongress DGK 2016", 2016)

Heat transfer in sedimentary deposits: effect of change in water saturation conditions on the thermal properties of soils interested by very shallow geothermal systems - Di Sipio, Eloisa; Bertermann, David (Abstract Volume GeoTirol2016, 2016)
Keywords: heat transfer; soil thermal properties; very shallow geothermal energy

Herstellung und Charakterisierung stickstoffreicher, qualitativ hochwertiger homo-epitaktischer Diamantfilme mittels Heißdraht-CVD - Eisenbeiß, Henrick; Stammler, Markus; Ristein, Jürgen; Ley, Lothar; Göbbels, Matthias; Neubauer, Jürgen (European Journal of Mineralogy, 2001)
UnivIS-Import:2015-03-09:Pub.2001.nat.dgeo.IGM.LM.herste

Heterastridium (Hydrozoa) from the Norian of Iran and Turkey - Senowbari-Daryan, Baba; Link, Michael (Palaeontographica, Abteilung A, Band 314, Lieferung 4-6, 2019)
The spherical hydrozoan genus Heterastridium Reuss is reported worldwide from Norian marine deposits in association with reef and other shallow-water organisms as well as with deep water organisms at some localities, the latter being result of transportation. Untill now 29 taxa of Heterastridium were described by previous authors, either as “species”, “subspecies”, “variety” or “forma”. Three species (H. conglobatum Reuss, H. lobatum Reuss and H. disciforme Gerth) are considered to be valid species. All other former taxa are synonyms of Heterastridium conglobatum representing different ontogenetic growth stages. Heterastridium is an index fossil of the Norian. Based on almost 1000 fossils from central Iran, on about 80 specimens from south Turkey and on about 100 thin-sections from morphologically differently structured and sized specimens, the following results have been obtained: (a) Generally, the surface of the small specimens, about 20 mm in diameter, is covered by large elements, called humps or spines in this paper. The development of the surface elements starts from the centre as small columns, becoming thicker by splitting when the specimen reached a diameter of about 20 mm. This first ontogenetic stage is characterised by small humps and/or warts. (b) By repeated spliting of the humps the middle-sized (young adults) and large specimens (adults) developed. The adult stage of Heterastridium conglobatum is characterised by small and equally distributed elements (warts). (c) Morphologically differently sized and structured specimens, described as “species”, “subspecies”, “variety” or “forma” by previous authors, are different ontogenetic growth stages of the species Heterastridium conglobatum Reuss. (d) In addition to H. conglobatum, Heterastridium lobatum Reuss and H. disciforme Schäfer & Grant-Mackie are valid species, which are differentiated by external morphological features (shape) and by an internally different architecture. Heterastridium has been classified as hydrozoan by previous authors and this view is followed here. This genus is a cosmopolitan index fossil of the Norian stage. Its occurrences in the Carnian and Rhaetian rocks, as described by some authors, is not proven and doubtful. Heterastridium is known from most continents, the main occurrence being the Tethyan realm. Some specimens of Heterastridium contain a biogenic object in the centre. It can be assumed that the colonisation of the core object by Heterastridium has most probably taken place at the sea floor followed by a rolling and may be later intermittently floating mode of life. The internal differences of Heterastridium and the Cretaceous genus Parkeria Carpenter are discussed.
CRIS-Team Scopus Importer:2019-12-10
Keywords: Heterastridium; Hydrozoa; Iran; Kasımlar Formation; Nayband Formation; Norian Tethys; Taurus Mountains; Turkey; Upper Triassic

Heterogeneous mantle underneath the North Atlantic: Evidence from water in orthopyroxene, mineral composition and equilibrium conditions of spinel peridotite from different locations at the Mid-Atlantic Ridge - Schmädicke, Esther; et al. (Lithos, 2011)
Keywords: Infrared spectroscopy; Geothermobarometry; Nominally anhydrous minerals; Mid-Atlantic Ridge; Spinel peridotite; Orthopyroxene