Early Jurassic anoxia triggered the evolution of the oldest holoplanktonic gastropod Coelodiscus minutus by means of heterochrony - Teichert, Sebastian; Nützel, Alexander (Acta Palaeontologica Polonica, 2015)
The tiny gastropod Coelodiscus minutus is superabundant in concretions of the Early Jurassic Posidonia Shale of South Germany which were formed under anoxic or extremely dysoxic conditions. Previous suggestions that C. minutus was a holoplanktonic organism are corroborated based on new evidence from exceptionally well-preserved specimens. The measurements of shell thickness show that the shell of Coelodiscus is very thin (mean 11 μm). In contrast to previous suggestions, the shell of Coelodiscus was not formed in three ontogenetic phases (embryonic, larval and adult shell) but in two phases comprising an embryonic and a secondary shell, the latter forming during an extended larval phase. Hostile conditions on the sea floor, absence or extreme scarcity of epibenthic animals as well as the small size also argue against a benthic life style of this gastropod. Coelodiscus minutus is the oldest known holoplanktonic gastropod. We speculate that Coelodiscus evolved during the Early Jurassic from a benthic precursor, which had a planktotrophic larval development. Probably under the influence of increasing frequency of dysoxic episodes along with hostile benthic conditions, the larval phase was extended neotenously and eventually, a holoplanktonic species evolved. During the Early Toarcian anoxic event, C. minutus was highly abundant in the plankton and dead shells rained down to the anoxic or dysoxic sea bottom. These thin and fragile shells formed an ooze similar to the pteropod ooze in the modern deep sea. The shells were preserved due to the absence or low level of deposit feeding and bioturbation as well as the formation of early diagenetic concretions.
UnivIS-Import:2015-07-08:Pub.2015.nat.dgeo.IGM.LP.earlyj
Keywords: anoxia; Coelodiscus minutus; Gastropoda; heterochrony; holoplanktonic gastropods; Jurassic; neoteny; Toarcian.

Early Jurassic rift valley-related alkaline lake deposits interbedded with Karoo flood basalts, Southern Namibia. - Stollhofen, Harald; Stanistreet, Ian G.; Gerschütz, Stephan (Lake basins through space and time, 2000)
UnivIS-Import:2015-03-09:Pub.2000.nat.dgeo.IGM.LG.earlyj

Early Neoproterozoic granitic gneisses in the Chinese Eastern Tianshan: Petrogenesis and tectonic implications - Huang, Bo-Tao; He, Zhen-Yu; Zhang, Ze-Ming; Klemd, Reiner; Zong, Ke-Qing; Zhao, Zhi-Dan (Journal of Asian Earth Sciences, 2014)
Early Neoproterozoic granitic gneisses are known from several locations such as the Xingxingxia, Alatage and Baluntai areas in the Central Tianshan Arc Terrane of the Chinese Eastern Tianshan, which is one of several Precambrian microcontinents within the southern Central Asian Orogenic Belt (CAOB). The petrogenesis and the tectonic significance of the early Neoproterozoic granitic gneisses have not been well constrained yet, resulting in an ambiguous understanding of the early tectonothermal evolution of the Chinese Eastern Tianshan. Geochronological results suggest that the protoliths of these granitic gneisses formed during a relatively short time period between ca. 970 and 915 Ma, mainly clustering at ca. 940 Ma. These peraluminous to strongly peraluminous granitic rocks show a common geochemical S-type granite affinity, involving low CaO, Na2O, Th and Y contents. Zircon saturation thermometry and Ti-in-zircon thermometry yielded a relatively low crystallization temperature of approximately 750-800 °C for the magmatic protolith of the granitic gneisses. Zircon Hf isotopic compositions of the Xingxingxia and Alatage granitic gneisses show ε Hf(t) values of -5.4 to 4.2, with T DM2 model ages of 1.53-2.14 Ga, indicating that their protoliths were derived by the recycling of older continental crust. We suggest that the early Neoproterozoic granitic rocks in the Chinese Eastern Tianshan were formed along an active continental margin. Furthermore, we propose that the Central Tianshan Arc Terrane was located at the periphery of Rodinia and separated from the Tarim Craton terrane in the early Neoproterozoic. © 2014 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.c3geoc.earlyn
Keywords: CAOB; Central Tianshan Arc Terrane; Neoproterozoic; Rodinia supercontinent; S-type granite affinity

Early Neoproterozoic granitic gneisses in the Chinese Eastern Tianshan: Petrogenesis and tectonic implications - Huang, Bo-Tao; He, Zhenyu; Zhang, Zeming; Klemd, Reiner; Zong, Keqing; Zhao, Zhi-Dan (Journal of Asian Earth Sciences, 2015)
Early Neoproterozoic granitic gneisses are known from several locations such as the Xingxingxia, Alatage and Baluntai areas in the Central Tianshan Arc Terrane of the Chinese Eastern Tianshan, which is one of several Precambrian microcontinents within the southern Central Asian Orogenic Belt (CAOB). The petrogenesis and the tectonic significance of the early Neoproterozoic granitic gneisses have not been well constrained yet, resulting in an ambiguous understanding of the early tectonothermal evolution of the Chinese Eastern Tianshan. Geochronological results suggest that the protoliths of these granitic gneisses formed during a relatively short time period between ca. 970 and 915 Ma, mainly clustering at ca. 940 Ma. These peraluminous to strongly peraluminous granitic rocks show a common geochemical S-type granite affinity, involving low CaO, Na2O, Th and Y contents. Zircon saturation thermometry and Ti-in-zircon thermometry yielded a relatively low crystallization temperature of approximately 750–800 °C for the magmatic protolith of the granitic gneisses. Zircon Hf isotopic compositions of the Xingxingxia and Alatage granitic gneisses show εHf(t) values of −5.4 to 4.2, with TDM2 model ages of 1.53–2.14 Ga, indicating that their protoliths were derived by the recycling of older continental crust. We suggest that the early Neoproterozoic granitic rocks in the Chinese Eastern Tianshan were formed along an active continental margin. Furthermore, we propose that the Central Tianshan Arc Terrane was located at the periphery of Rodinia and separated from the Tarim Craton terrane in the early Neoproterozoic.<br
Keywords: CAOB; Central Tianshan Arc Terrane; Neoproterozoic; Rodinia supercontinent; S-type granite affinity

Early Ordovician lithistid sponge-Calathium reefs on the Yangtze Platform and their paleoceanographic implications - Kießling, Wolfgang; Li, Qijian; Li, Yue; Wang, Jianpo (Palaeogeography, Palaeoclimatology, Palaeoecology, 2015)
Lithistid sponge- Calathium-microbial reefs were widespread on the Yangtze Platform during the Early Ordovician and are well studied. However, the biological affinity and the role of Calathium in these reefs have remained unclear up to now. We document lithistid sponge-. Calathium reefs from the Upper Hunghuayuan Formation (Early Floian) at Huanghuachang in Hubei, South China. These reefs have a three-dimensional skeletal framework that is mostly produced by Calathium and lithistid sponges. Calathium had a critical role in reef construction, as demonstrated by well-developed lateral outgrowths, which connected individuals of the same species and with lithistid sponges. Bryozoans, stromatoporoids and microbial components were secondary reef builders. Morphological, constructional and functional analyses provide evidence that Calathium was a sponge-grade metazoan rather than a receptaculitid alga as previously thought. At the dawn of the Ordovician Radiation, these small-scaled patch reefs thus represent the initial rebound of metazoan-dominated reefs after the Late-Early Cambrian archaeocyath reef crisis. Gradual global cooling through the Early Ordovician may have been a key driver for the return of metazoan reef
UnivIS-Import:2015-04-02:Pub.2015.nat.dgeo.IGM.LP.earlyo
Keywords: Calathium; Global cooling; Lithistid sponges; Reefs; Yangtze Platform

Early Ordovician sponge-Calathium-microbial reefs on the Yangtze Platform margin of the South China Block - Li, Qijian; Lin, Yue; Kießling, Wolfgang (Gff, 2014)
Early Ordovician (late Tremadocian to early Floian) reefs on the Yangtze Platform margin of the Hunghuayuan Formation at Zhangzhai section in southeastern Guizhou, South China show three types of reefs in two broad categories: microbial-dominated (stromatolite and lithistid sponge-Calathium-calcimicrobial) reefs and metazoan-dominated (lithistid sponge-Calathium) reefs. These reef types represent different communities controlled by varying environmental settings. Stromatolites tended to develop in the shallow subtidal zone, whereas unlaminated calcimicrobial mounds and metazoan-dominated reefs thrived at greater depths. This is the first report on metazoan-dominated reefs at the platform margin of the Hunghuayuan Formation. © 2014 © 2014 Taylor & Francis.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LP.earlyo
Keywords: calathid; Early Ordovician; metazoan-dominated reefs; microbialite; Yangtze Platform margin

Early Palaeozoic deep subduction of continental crust in the Kyrgyz North Tianshan: Evidence from Lu-Hf garnet geochronology and petrology of mafic dikes. - Rojas-Agramonte, Yamirka; Herwartz, Daniel; Garcia-Casco, Antonio; Kroener, Alfred; Alexeiev, Dmitriy V.; Klemd, Reiner; Buhre, Stephan; Barth, Matthias (Contributions To Mineralogy and Petrology, 2013)
High-pressure and ultrahigh-pressure (UHP) eclogite-bearing metamorphic assemblages in the North Tianshan of Kyrgyzstan are known from the Aktyuz and Makbal areas, where eclogites and garnet amphibolites are associated with continental rocks such as granitoid gneisses in Aktyuz and shallow-water clastic (passive margin?) metasediments in Makbal. We present the first Lu-Hf isotope data for an eclogite and two garnet amphibolite samples from the two metamorphic terranes which, combined with petrological analysis, tightly constrain the age of high-pressure metamorphism in the Kyrgyz North Tianshan. A five-point isochron for an Aktyuz eclogite sample provides a Lu-Hf age of 474.3 ± 2.2 Ma, and a four-point isochron on a Makbal sample corresponds to 470.1 ± 2.5 Ma. A prograde, subduction-related path is inferred for both samples with peak P-T conditions ranging from 1.4 to 1.6 GPa and 610-620 °C. A further Makbal sample provided a significantly older Lu-Hf age of 486 ± 5.4 Ma, most likely due to late alteration in the sample (late addition of unradiogenic Hf). We conclude that garnet growth in all three samples occurred around ca. 474 Ma and that these rocks likely experienced UHP metamorphism contemporaneously. Our results support previous geochronological evidence for an Early Ordovician collision belt in the North Tianshan and allow refinement of a tectonic model involving subduction of thinned continental crust to considerable depth along the margin of a small microcontinent. © 2013 Springer-Verlag Berlin Heidelberg.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.c3geoc.earlyp
Keywords: Aktyuz; Kyrgyzstan; Lu-Hf; Mafic dike; Makbal; Northern Tianshan

Early Permian deposits of the Huab area, Namibia: A continental to marine transition. - Holzförster, Frank; Stollhofen, Harald; Stanistreet, Ian G. (Communications - Geological Survey of Namibia, 2000)
Understanding the facies development of the Huab area is important as this area provides a bridge between the Permian deposits of South Africa and southern Namibia and those of the Paraná Basin in Brazil. Post-glacial Permian environments in the Huab area were initiated by widespread, meandering river systems recorded by sandy point bar and coal-bearing floodplain deposits of the Verbrandeberg Formation. The base of the Tsarabis Formation is dominated by laterally amalgamated braided channel sandstones. These fluvial units interfinger upwards with wave-dominated deltaic and shoreface deposits bearing a variety of marine trace fossils. The overlying Huab Formation contains large-scale stromatolite ridges with flat pebble conglomerates formed in tidal channels between the ridges. The entire succession was later buried by landward-onlapping marine mud- and marlstones recording the peak of an overall transgressive development. Facies architecture varies considerably in cross-section perpendicular to the present-day continental margin, which is interpreted to reflect syn-depositional normal faulting during early South Atlantic rifting. This requires detailed palaeo-environmental analyses because it is assumed that marine-influenced Karoo-aged rocks in Namibia and Brazil trace the axis of a broad southern South Atlantic intracontinental rift zone.
UnivIS-Import:2015-03-09:Pub.2000.nat.dgeo.IGM.LG.earlyp

Early Pleistocene banded iron-rich sedimentary rocks at Cape Vani, Milos Island, Greece: A modern analogue of Precambrian banded iron formations? - Sun, Si; Klemd, Reiner; Voudouris, Panagiotis (Sedimentary Geology, 2022)
The genesis of banded iron formations is commonly associated with anoxic and iron-rich (ferruginous) marine conditions throughout the Archean to Palaeoproterozoic, and occasionally in the Neoproterozoic. In recent studies, 2 million-year-old banded iron-rich sedimentary rocks with alternating Fe- and Si-rich bands occurring in the Cape Vani sedimentary basin on Milos island (Greece) were interpreted to be a modern analogue of Precambrian banded iron formations. This interpretation is mainly due to the discovery of photoferrotrophic-like filamentous fossils in massive iron-rich cherty beddings of another subbasin about 450 m to the south. In this study, we re-examined the stratigraphy and lithology of the Cape Vani basin, carried out detailed petrographic, mineralogical and geochemical investigations of the iron-rich sedimentary rocks, as well as volcaniclastic/volcanic conglomerates and banded hydrothermal veins that are in close spatial association with the iron-rich sedimentary rocks. The Fe2O3 content of the banded iron-rich sedimentary rocks ranges from 0.41 to 11.02 wt% (2.73 wt% on average), far lower than that required per definition for banded iron formations. In addition, the banded iron-rich sedimentary rocks contain substantial clastic materials. Samples with stronger silicification, however, usually contain less clastic materials. The non-clastic components occur as siliceous matrix comprising the same mineral assemblage as the banded hydrothermal veins. These components occur in the interspaces of the clastic materials, within cavities, microfractures and veins crosscutting the layers. Fe2O3, principally reflecting hematite, is intimately linked with the presence of non-clastic materials. Therefore, the non-clastic materials are interpreted as post-depositional products associated with silicification during later stage hydrothermal activities, rather than being syn-depositional as the minerals in Precambrian banded iron formations. Consequently, the Milos banded iron-rich sedimentary rocks cannot be an analogue of Precambrian banded iron formations, seeing their lithological and genetical differences. The geochemical results reveal that both the banded iron-rich sedimentary rocks and the massive iron-rich cherty beddings have the same clastic provenance as the volcaniclastics/volcanic conglomerates, but the massive iron-rich cherty beddings contain more hydrothermal contributions due to more intensive fluid-rock interaction. Thus, the two types of iron-rich sedimentary rocks are considered as clastic sedimentary rocks with varying degrees of hydrothermal overprinting. The massive iron-rich cherty beds were generally subjected to stronger hydrothermal overprinting, and, therefore, contain more siliceous matrix and Fe2O3. The enrichment of Fe is due to post-depositional hydrothermal fluid infiltration to the primary sediment piles. The primary layer planes of the banded iron-rich rocks, their interconnected pores and fractures provided preferential pathways for the hydrothermal fluids, and resulted in denser precipitation of Fe(III) (oxy)hydroxides and SiO2 cement therein. The alternating bands in the banded iron-rich sedimentary rocks, therefore, reflect cyclic permeabilities of the layers (i.e., primary sedimentary planes and porosities), rather than cyclic precipitation of Fe- and Si-minerals. This study also sheds light on an alternative formation mechanism for banded structures in Fe- and Si-rich sedimentary rocks similar to those of Precambrian banded iron formations.
CRIS-Team Scopus Importer:2022-07-22
Keywords: Banded iron formation; Chemical sedimentary rock; Fe(III) precipitation; Hydrothermal fluids; Milos iron-rich sedimentary rock; Silicification

Early Silurian positive δ13C excursions and their relationships to glaciations, sea-level changes and extinction events: Discussion - Cramer, Bradley D.; Munnecke, Axel (Geological Journal, 2008)
Keywords: Silurian; d13C excursions; glaciation; sea-level changes; extinction events

Early Silurian (Telychian) bryozoan reefs in the epeiric sea of South China: Are heterotroph metazoan buildups promoted by internal waves? - Munnecke, Axel; Li, Qijian; Ernst, Andrej; Yu, Shenyang; Li, Yue (Sedimentary Geology, 2018)

Early Triassic microconchids from the Perth Basin, Western Australia: Palaeoecology and flourishing in the aftermath of the end-Permian mass extinction - Yang, Hao; Chen, Zhong Qiang; Mei, Xi; Sun, Yadong (Geological Journal, 2021)
Microconchids are small spiral worm tubes convergent with spirorbin polychaetes, and they are not a well-known fossil group in terms of taxonomy and spatiotemporal distributions. Here, we report for the first time microconchid species Microconchus cf. utahensis from the Lower Triassic borehole sections in the Perth Basin, Western Australia, which were situated in the interior sea of inland Gondwana during the Permian–Triassic (P–Tr) transition. The newly found microconchids encrust bivalve Claraia shells, which occur in the forms of shell beds in core samples of boreholes in the Perth Basin. These microconchids, together with Claraia spp., form a high-abundance, low-diversity assemblage, which lived in a shallow, restricted interior sea, with euxinic to anoxic redox conditions. These tiny encrusting organisms flourished in the oxygen-poor habitats, where other benthos was very rare. They represent disaster forms in the aftermath of the P–Tr mass extinction. Global dataset of the Triassic microconchids shows that this clade inhabited a wide range of environments from continental basins, nearshore, restricted shallow sea, restricted inner platform, open platform, to shelf and basin, all of which were oxygen-limited settings in that time. Geographically, microconchids were widespread in the low-latitude regions (i.e., South China of eastern Palaeo-Tethys, western Palaeo-Tethys, Neo-Tethys, western coasts, and atolls of the Panthalassic Ocean) and to northern and southern moderate-high latitude regions (i.e., Greenland of Boreal seas and Perth Basin of inland Gondwana, respectively) during the Early Triassic. The spatiotemporal distributions of microconchids suggest the flourishing of disaster organisms following the P–Tr extinction. Both small body size and high tolerance to environmental stresses promoted microconchids to succeed in the Triassic.
CRIS-Team Scopus Importer:2021-03-19
Keywords: disaster taxa; end-Permian mass extinction; euxinic to anoxic conditions; inland Gondwana; worm tube

Early Ultrastructural Changes in Biopsies From Patients With Symptomatic CKD of Uncertain Etiology - Daniel, Christoph; Enghard, Philipp; Ratnatunga, Neelakanthi; Wijetunge, Sulochana; Wazil, A. W.M.; Zwiener, Christian; Barth, Johannes; Chandrajith, Rohana; Klewer, Monika; Eckardt, Kai-Uwe; Amann, Kerstin Ute; Freund, Paul; et al. (Kidney International Reports, 2023)
Introduction: Although the investigation of chronic kidney disease of uncertain etiology (CKDu) has identified many possible influencing factors in recent years, the exact pathomechanism of this disease remains unclear. Methods: In this study, we collected 13 renal biopsies from patients with symptomatic CKDu (Sym-CKDu) from Sri Lanka with well-documented clinical and socioeconomic factors. We performed light microscopy and electron microscopic evaluation for ultrastructural analysis, which was compared with 100 biopsies from German patients with 20 different kidney diseases. Results: Of the 13 Sri Lankan patients, 12 were men (92.3%), frequently employed in agriculture (50%), and experienced symptoms such as feeling feverish (83.3%), dysuria (83.3%), and arthralgia (66.6%). Light microscopic evaluation using activity and chronicity score revealed that cases represented early stages of CKDu except for 2 biopsies, which showed additional signs of diabetes. Most glomeruli showed only mild changes, such as podocyte foot process effacement on electron microscopy. We found a spectrum of early tubulointerstitial changes including partial loss of brush border in proximal tubules, detachment of tubular cells, enlarged vacuoles, and mitochondrial swelling associated with loss of cristae and dysmorphic lysosomes with electron-dense aggregates. None of these changes occurred exclusively in Sym-CKDu; however, they were significantly more frequent in these cases than in the control cohort. Conclusion: In conclusion, our findings confirm the predominant and early alterations of tubular structure in CKDu that can occur without significant glomerular changes. The ultrastructural changes do not provide concrete evidence of the cause of CKDu but were significantly more frequent in Sym-CKDu than in the controls.
CRIS-Team Scopus Importer:2023-03-17
Keywords: chronic kidney disease of uncertain etiology (CKDu); lysosomal alteration; mitochondrial swelling; renal biopsy; transmission electron microscopy; tubular injury

EBSD at high temperatures in metals and minerals - Bestmann, Michel; et al. (Microscopy and Microanalysis, 2003)

Echinoderm Research 2010. 7th European Conference on Echinoderms, Göttingen, October 2-9, 2010. Abstract Volume and Field Guide to Excursions - Reich, Mike; Reitner, Joachim; Roden, Vanessa; Thuy, Ben (Universitätsdrucke Göttingen, 2010)

Eclogite-facies rocks in the Saxonian Erzgebirge, Germany: high pressure metamorphism under contrasting P-T conditions - Schmädicke, Esther; et al. (Contributions To Mineralogy and Petrology, 1992)

Eclogite-facies rocks in the Saxonian Erzgebirge, Germany: High pressure metamorphism under contrasting P T conditions. - Schmädicke, Esther; et al. (Contributions To Mineralogy and Petrology, 1992)
The metamorphic sequences of the Saxonian Erzgebirge were thoroughly overprinted by a Variscan medium-pressure event under amphibolite facies conditions. However, eclogitic relics documenting an older high-pressure event are widespread. P-T conditions of the eclogite-facies metamorphism systematically decrease, over a distance of 50 km, from about >29 kbar/850°C, in the central part, to 20-24 kbar/650°C, in the westernmost part of the Erzgebirge crystalline complex. A distinct gap in P-T conditions exists between the central and the western Erzgebirge coinciding with the fault zone of the Flöha syncline. Therefore, the eclogitebearing sequences are assumed to represent at least two different nappe units. The lower-grade eclogite assemblages in the western Erzgebirge display a continuous metamorphic zonation with a gradual decrease of peak metamorphic temperatures towards the west. Assemblages formed in the stability field of coesite and thus indicating a regional ultra-high pressure metamorphism, are restricted to the central Erzgebirge, where they are widespread in the eclogites, but also present in metaacidic country rocks. The same high-temperature/high-pressure conditions, testifying to a burial of at least 100 km, were independently recorded for the ultramafic garnet pyroxenites associated with the eclogites of the central Erzgebirge. Mineral relics included in the eclogite phases and mineral assemblages formed by retrograde reactions permit reconstruction of the prograde and retrograde P-T paths in the different parts of the Erzgebirge crystalline complex. © 1992 Springer-Verlag.
UnivIS-Import:2017-03-24:Pub.1992.nat.dgeo.IGM.profes_1.eclogi

Ecological change during the early Emsian (Devonian) in the Tafilalt (Morocco), the origin of the Ammonoidea, and the first African pyrgocystid edrioasteroids, machaerids and phyllocarids - Klug, Christian; Korn, Dieter; Rücklin, Martin; Schemm-Gregory, Mena; de Baets, Kenneth; Mapes, Royal H.; Kröger, Björn (Palaeontographica Abteilung A-Palaozoologie-Stratigraphie, 2008)
The majority of the macrofossils from the two faunas are systematically described; the following new taxa are introduced: the bivalve Eonuculoma babini n. gen. et sp., the orthoceratids Chebbioceras erfoudense n. gen. et sp., Infundibuloceras brevimira n. gen. et sp. and Plagiostomoceras hassichebbiense n. sp., the bactritoid Cyrtobactrites scheffoldi n. sp., the ammonoid Metabactrites ernsti n. sp., and the machaerid Aulakolepos rugatus n. sp., the phyllocarids Nahecaris jannae n. sp.and N. malvinae n. sp. as well as the edrioasteroid Rhenopyrgus flos n. sp. The latter taxa represent the first records of the families Pyrgocystidae, Lepidocoleidae and of phyllocarid carapaces from Africa.
Keywords: Emsian; cephalopoda; machaeridia; phyllocarida; edrioasteroidea; Morocco

Ecological stasis in Spinicaudata (Crustacea, Branchiopoda)? Early Cretaceous clam shrimp of the Yixian Formation of north-east China occupied a broader realized ecological niche than extant members of the group - Hethke, Manja; Fürsich, Franz; Jiang, Baoyu; Wang, Bo; Chellouche, Patrick; Weeks, Stephen C. (Palaeontology, 2019)
The palaeoecology of Spinicaudata, the dominant group of benthic invertebrates in many pre-Cenozoic freshwater environments, remains poorly understood. In analogy with extant taxa, it has been oversimplified and often reduced to shallow, temporary environments characterized by few trophic levels, implying ecological stasis from the Devonian to the Recent. We excavated 43 horizons of the Lower Cretaceous Yixian Formation (Anjiagou and Hengdaozi beds) to evaluate whether spinicaudatan ecology can be simplified to such an extent. Sedimentological evidence suggests general perennial conditions during the excavated lake interval. Based on 33 226 specimen counts, we identified three arthropod-dominated macrobenthic associations and two assemblages. Response curves indicate that the spinicaudatan Eosestheria middendorfii was exceptionally tolerant to environmental gradients, followed, in decreasing order, by mayfly larvae, water boatmen and oligochaetes. Many spinicaudatan-yielding layers represent death after reproductive senescence rather than mass-mortality events. Spinicaudatan size varies significantly according to faunal association. A forward stepwise regression model suggests that growth responded to population density and diversity: lower densities and higher diversities triggered fast growth, and vice versa. The proposed strong density effect on carapace size has been corroborated by rearing experiments: as for E. middendorfii, natural log regression provided the best fit for the two extant species Eulimnadia texana and Eocyzicus argillaquus. Hence, E. middendorfii was a tolerant and morphologically variable species adapted to perennial waters and the frequent presence of higher trophic levels. Although there are rare records of extant taxa co-occurring with fish, the described Early Cretaceous environment is commonly not inhabited by extant Spinicaudata.
CRIS-Team Scopus Importer:2019-05-02
Keywords: ecology; Eosestheria middendorfii; fossil Lagerstätte; Jianshangou Member; Spinicaudata; Yixian Formation

Ecological, taxonomic, and taphonomic components of the post-Paleozoic increase in sample-level species diversity of marine benthos - Kowalewski, Michal; Kießling, Wolfgang; Aberhan, Martin; Fürsich, Franz; Scarponi, Daniele; Barbour, Susan L.; Hoffmeister, Alan P. (Paleobiology, 2006)
Biological veracity of the sharp diversity increase observed in many analyses of the post-Paleozoic marine fossil record has been debated vigorously in recent years. To assess this question for sample-level ("alpha") diversity, we used bulk samples of shelly invertebrates, representing three major fossil groups (brachiopods, bivalves, and gastropods), to compare the Jurassic and late Cenozoic sample-level diversity of marine benthos. After restricting the data set to single-bed, whole-fauna, bulk samples (n ≥ 30 specimens) from comparable open marine siliciclastic facies, we were able to retain 427 samples (255 Jurassic and 172 late Cenozoic), with most of those samples originating from our own empirical work. Regardless of the diversity metric applied, the initial results suggest that standardized sample-level species (or genus) diversity, driven by evenness and/or richness of the most common taxa, increased between the Jurassic and late Cenozoic by at least a factor of 1.6. When the data are partitioned into the three dominant higher taxa, it becomes clear that (1) the bivalves, which dominated the samples for both time intervals, increased in sample-level diversity between the Jurassic and the late Cenozoic by a much smaller factor than the total fauna; (2) the removal of brachiopods, which were a noticeable component of the Jurassic samples, did not significantly affect standardized sample-level diversity estimates; and (3) the gastropods, which were rare in the Jurassic but common in many late Cenozoic samples, contributed notably to the increase in sample-level diversity observed between the two time intervals. Parallel to these changes, the samples revealed secular trends in ecological structure, including Jurassic to late Cenozoic increases in proportion of (1) infauna, (2) mobile forms, and (3) non-suspension-feeding organisms. These trends mostly persist when data are restricted to bivalves. Supplementary analyses indicate that these patterns cannot be attributed to sampling heterogeneities in paleolatitudinal range, lithology, or paleoenvironment of deposition. Likewise, when data are restricted to samples dominated by species with originally aragonitic shells, the observed temporal changes persist at a comparable magnitude, suggesting that the pervasive loss of aragonite in the older fossil record is unlikely to have been the primary cause of the observed patterns. The comparable ratio of identified to unidentified species and genera, observed when comparing the Jurassic and late Cenozoic samples, indicates that the relatively poorer (mold/cast) preservation of Jurassic aragonite species also is unlikely to have been responsible for the observed patterns. However, the diagenesis-related taphonomic and methodological artifacts cannot be ruled out as an at least partial contributor to the observed post-Paleozoic changes in diversity, taxonomic composition, and ecology (the outcomes of the three tests of the diagenetic bias available to us are incongruent). The study demonstrates that the post-Paleozoic trends in the sample-level diversity, ecology, and taxonomic structure of common taxa can be replicated across multiple studies. However, the diversity increase estimated here is much less prominent than suggested by many previous analyses. The results also narrow the list of causative explanations down to two testable hypotheses. The first is diagenetic bias - a spurious trend driven by either (a) increasing taphonomic loss of small specimens in the older fossil record or (b) a shift in sampling procedures between predominantly lithified rocks of the Mesozoic and predominately unlithified, and therefore sievable, sediments of the late Cenozoic. The second hypothesis is genuine biological changes - macroevolutionary trends in the structure of marine benthic associations through time, consistent with predictions of several related models such as evolutionary escalation, increased ecospace utilization, and the Mesozoic marine revolution. Future studies should focus on testing these two rival models, a key remaining challenge for identifying the primary causative mechanism for the long-term changes in sample-level diversity, ecology, and taxonomic structure observed in the Phanerozoic marine fossil record. © 2006 The Paleontological Society. All rights reserved.
UnivIS-Import:2015-04-14:Pub.2006.nat.dgeo.IGM.LP.ecolog
Keywords: taxonomy; ecology; diversity; post-Paleozoic; marine benthos; sample-level

Economic, geological and technical potential mapping test for GSHP systems in Europe - Perego, Rodolfo; Pera, Sebastian; Galgaro, Antonio; Dalla Santa, Giorgia; Cultrera, Matteo; de Carli, Michele; Emmi, Giuseppe; Bertermann, David; Müller, Johannes; Mendrinos, Dimitrios; Karytsas, Constantine; Vercruysse, Jacques; et al. (Proceedings of the European Geothermal Congress 2019, 2019)

Editorial: Crustose coralline red algae frameworks and rhodoliths: Past and present - Rebelo, Ana Cristina; Teichert, Sebastian; Bracchi, Valentina A.; Rasser, Michael W.; Basso, Daniela (Frontiers in Earth Science, 2022)

Editorial preface to special issue: Triassic at the dawn of modern world in honour of Prof. Leopold Krystyn - Sun, Yadong; Richoz, S.; Kürschner, W. M. (Global and Planetary Change, 2022)
CRIS-Team Scopus Importer:2022-01-21
Keywords: biostratigraphy; climate change; mass extinction; palaeontology; Triassic

Effect of amorphous phases during the hydraulic conversion of alpha-TCP into calcium-deficient hydroxyapatite - Hurle, Katrin; Neubauer, Jürgen; Bohner, Marc; Döbelin, Nicola; Götz-Neunhoeffer, Friedlinde (Acta Biomaterialia, 2014)
Powders of α-tricalcium phosphate (α-TCP), which readily react with water to form calcium-deficient hydroxyapatite (CDHA), are frequently used in bone cements. As, for clinical applications, it is important to adjust the setting reaction of the cements to a reasonable reaction time, exact knowledge of the hydration mechanism is essential. It is known that prolonged milling results in partial amorphization of α-TCP powders and that dissolution of the amorphous phase significantly accelerates the hydration, but it is not clear yet when the amorphous phase reacts in comparison to the crystalline α-TCP. Therefore the aim of this study was to investigate the development of quantitative phase content of α-TCP samples during hydration. For this purpose, three α-TCP powders, containing 0, 16 and 71 wt.% of amorphous phase (ATCP), were mixed with either deionized water or a 0.1 M Na 2HPO4 aqueous solution. The crystalline evolution of the paste was assessed quantitatively during the first 48 h of hydration at 23 °C by G-factor quantification. The present investigations demonstrate that ATCP reacted earlier than crystalline α-TCP. The results also suggest the formation of an X-ray amorphous phase during the hydraulic conversion formation of α-TCP into CDHA. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LM.effect
Keywords: Amorphization; Bone substitute; Calcium phosphate cement; CDHA; Quantitative in situ XRD

Effect of inorganic admixtures on the early hydration of Monocalciumaluminate (CA_1-x_F_x_) - Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen (Proceedings of the 11th International Congress on the Chemistry of Cement (ICCC): Cement's Contribution to Development in the 21st Century, 2003)
UnivIS-Import:2015-03-09:Pub.2003.nat.dgeo.IGM.LM.effect_9

Effect of Mg2+ content on lattice parameter and phase transformation temperature of β-α TCP - Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; Göbbels, Matthias; Enderle, Ralph (European Cells & Materials, 2006)

Effect of polymer latexes with cleaned serum on the phase development of hydrating cement pastes - Kong, Xiangming; Pakusch, Joachim; Jansen, Daniel; Emmerling, Sebastian; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (Cement and Concrete Research, 2016)
The effects of polymer latexes on cement hydration were investigated by the combination of isothermal calorimetry, in-situ XRD and Cryo-SEM. Two model latexes with varied amounts of anionic charges were used for measurements after cleaned by dialysis to remove the serum components. This study confirms that in-situ XRD technique can be successfully adapted to hydrating cementitious systems in the presences of polymer latexes to quantitatively follow evolution of mineral phases involved in cement hydration. Results show that both polymers retard aluminate reaction and depress silicate reaction, by delaying the dissolution of CA, anhydrite and gypsum and consequently the formation of ettringite, and reducing the dissolution of CS and the formation of C-S-H. The anionic colloidal polymers exhibit more pronounced retardation effect on aluminate reaction than on silicate reaction due to stronger electrostatic interaction between the polymer particles and the positively charged aluminate phases. The more charged latex shows stronger retardatio
Keywords: Cement (D); Hydration (A); Latex (D); Retardation (A); X-ray diffraction (B)

Effect of polymers on cement hydration: A case study using substituted PDADMA - Jansen, Daniel; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; Härzschel, Reinhard; Hergeth, Wolf Dieter (Cement & Concrete Composites, 2013)
A study was carried out, using heat flow calorimetry and quantitative X-ray diffractometry, of the different influences which are exerted by types of cationic Polydiallyldimethylammonium (PDADMA) displaying different anionic counterions on the hydration behavior of an Ordinary Portland Cement (OPC). It was shown that the influence of the cationic polymer PDADMA on the hydration of the cement will tend to be strongly dependent on the nature of the anionic counterion. In case of OH-, more calcium sulfate will tend to be dissolved in the early stages, which acts in turn as an accelerator for the hydration of the C3S phase. In case of SO42- there will tend to occur a secondary gypsum precipitation, which will in turn act to lower the Ca 2+ - content in the mix water, leading to a retardation of the hydration process compared to the hydration in absence of polymer. © 2012 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LM.effect
Keywords: Calorimetry; Cement hydration; PDADMAC; Quantitative XRD-analysis

Effect of sintering parameters on phase evolution and strength of dental lithium silicate glass-ceramics - Lohbauer, Ulrich; Belli, Renan; Abdalla Alonso, Alexandre; Götz-Neunhoeffer, Friedlinde; Hurle, Katrin (Dental Materials, 2019)
Objective: With the establishment of CAD/CAM technology, competing lithium silicate based formulations have been introduced for clinical use, but little is known about their phase composition. Here we investigate a commercially available SiO2-Al2O3-K2O-Li2O-P2O5-ZrO2 system to evaluate the crystal phase evolution during the second heat treatment by changing the main crystallization parameters. Methods: With a focus on the final stage of crystallization, we characterized the dimensional changes in the crystallographic structure of the residual Li2SiO3 and the lithium orthophosphate (Li3PO4) phases with variations in crystallization parameters, i.e. time, temperature and cooling rate over the range of the glass transition temperature Tg. The phase fractions (crystalline and glass) and the sizes of coherent scattering domains (CSDs) were resolved by means of quantitative X-Ray Diffraction using Rietveld refinement combined with an external standard method (G-factor). Biaxial flexure testing was conducted to evaluate the influence of crystallization parameters on the characteristic strength and natural defect distribution. Results: An increase in crystallization temperature from 840 to 880 °C resulted in a significant reduction of the Li2Si2O5 content, which indicated a reversion of the Li2SiO3 to Li2Si2O5 phase transformation. Reduction to 800 °C had no significant effect. Furthermore, the CSD sizes of Li2SiO3 and Li3PO4 continuously increased with increasing temperature, which was accompanied by an increase in strength parameters. Reducing the cooling rate over the range of Tg resulted in an increased strength at low failure probabilities. Significance: These findings help to establish recommendations for adjustment of the crystallization protocol, which has potential to increase the clinical reliability of the material investigated.
CRIS-Team Scopus Importer:2019-08-09
Keywords: Ceramics; Crystallization; Materials science; Restorative materials; X-ray Crystallography

Effect of temperature on the hydration of Portland cement blended with siliceous fly ash - Deschner, Florian; Lothenbach, Barbara; Winnefeld, Frank; Neubauer, Jürgen; Neubauer, Jürgen (Cement and Concrete Research, 2013)
The effect of temperature on the hydration of Portland cement pastes blended with 50 wt.% of siliceous fly ash is investigated within a temperature range of 7 to 80 C. The elevation of temperature accelerates both the hydration of OPC and fly ash. Due to the enhanced pozzolanic reaction of the fly ash, the change of the composition of the C-S-H and the pore solution towards lower Ca and higher Al and Si concentrations is shifted towards earlier hydration times. Above 50 C, the reaction of fly ash also contributes to the formation of siliceous hydrogarnet. At 80 C, ettringite and AFm are destabilised and the released sulphate is partially incorporated into the C-S-H. The observed changes of the phase assemblage in dependence of the temperature are confirmed by thermodynamic modelling. The increasingly heterogeneous microstructure at elevated temperatures shows an increased density of the C-S-H and a higher coarse porosity. © 2013 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LM.effect_1
Keywords: Blended cement (D); Fly ash (D); Hydration (A); Modelling (E); Temperature (A)

Effect of varying CA2/CA ratios in Calcium-Aluminate-Calcite-mixtures analysed by combined QXRD, µ-CT and flexural-strength testing - Goergens, Julian; Belli, Renan; Schulbert, Christian; Götz-Neunhoeffer, Friedlinde (4th International Conference on the Chemistry of Construction Materials - ICCCM 2022, 2022)
Common calcium aluminate cements (CAC) may vary in their CA2 to CA ratio. While CA is the main phase of most CACs and is responsible for the initial strength, the CA2 phase has also received more attention in the last few decades. The reason for this is the higher Al-content of CA2 and thus the ability to produce more AH3 than CA as well as a higher thermic stability. In Calciumsulfoaluminate-cements (CSA), AH3 is considered to promote strength [1]. A gradual increase in the CA2 content and thus a change in the CA2/CA ratio in the clinker in CAC can be achieved by mixing of two cements, one CA-rich and one CA2-rich CAC. According to this approach, two industrial CACs were mixed in this work and six different CA2/CA-ratios were analysed with the following methods: QXRD after 1, 7 and 28 days of hydration demonstrates the quantitative progress of hydration, the clinker phase hydration degree as well as changes in AH3 and other hydrate phase quantities over time. Micro-computer tomography (µ-CT) of selected mixtures after 28 days enables a three-dimensional, non-destructive view of the inside of the sample, porosity and density heterogenities. The newly introduced B3B-method [2] for testing of the flexural strength in combination with the data evaluation according to Weibull (all mixes after 7 and 28 days) allows an interpretation of the mechanical properties. The combination of these three methodologies reveals that the mechanical properties deteriorate significantly from a CA2/CA ratio of 70:30 on to higher ones. The reasons for this are the macro-porosity, insufficient amounts of CA in the non-hydrated residue and differences in viscosity. [1] Chang J, Zhang Y, Shang X, Zhao X, Yu X. Effects of amorphous AH3 phase on mechanical properties and hydration process of C4A3š-CšH2-CH-H2O system. Construction and Building Materials 2017:133:314–322. [2] Börger A, Supancic P, Danzer R. The ball on three balls test for strength testing of brittle discs: stress distribution in the disc. J Eur Ceram Soc. 2002;22:1425-36. <

Effects of diagenesis on the astrochronological approach of defining stratigraphic boundaries in calcareous rhythmites: The Tortonian GSSP - Westphal, Hildegard; Munnecke, Axel; Brandano, Marco (Lethaia, 2008)
Since the establishment of astrochronology, calcareous rhythmites are frequently used as the basis of high-resolution chronostratigraphy. In particular for the Neogene, calcareous rhythmites serve as stratotypes and for absolute dating of stratigraphic boundaries (Global Stratotype Sections and Points -GSSPs). However, the exact mechanisms responsible for the formation of the rhythmic intercalation of lithologies in such successions are complex and not easily reconstructed. To a large extent this is the effect of diagenetic modifications of the original sediment. Here, two examples of Neogene calcareous rhythmites are studied; the Monte dei Corvi section and the Monte Gibliscemi section. The first is the GSSP location of the Serravallian-Tortonian boundary, whereas the second is an auxiliary stratotype for the same boundary. During the past years, astrochronological approaches were applied to these successions to considerably increase time resolution compared to the elaborated biostratigraphic database. The present study focuses on micropetrographic, trace element and clay mineralogical methods in order to gain a better understanding of the genesis of the rhythmites. In the Monte Gibliscemi section, sediment parameters that are robust against diagenetic change clearly reflect primary differences, i.e. cyclical environmental changes. In contrast, no clear primary signal is determined for the Monte dei Corvi section on a couplet scale, leaving the origin of the rhythm ambiguous. This impedes the interpretation of the latter and the comparability between the two successions, and also compromises any bed-by-bed correlation between the two. The unclear origin of the rhythmites of Monte dei Corvi introduces uncertainty into the applicability of astrochronology to this succession. © Journal compilation © 2008 The Lethaia Foundatio
Keywords: Astrochronology; Calcareous rhythmites; rhythmites; GSSP; diagenesis; stratigraphic boundaries; Tortonian

Effects of fluid boiling on Au and volatile element enrichment in submarine arc-related hydrothermal systems - Falkenberg, Jan; Keith, Manuel; Haase, Karsten; Bach, Wolfgang; Klemd, Reiner; Strauss, Harald; Yeo, Isobel A.; Rubin, Kenneth H.; Storch, Bettina; Anderson, Melissa O. (Geochimica Et Cosmochimica Acta, 2021)
Shallow (<1500 mbsl) submarine arc-related hydrothermal systems can host base (Cu), precious (Au) and volatile elements (As, Se, Sb, Te, Tl) in significant quantities. Their wide application in the high-tech industry, but a potential eco-toxicological footprint gives them a strategic importance. However, the processes that concentrate these elements in submarine arc-related hydrothermal systems, compared to their mid-ocean ridge counterparts are still debated, and it is unclear whether boiling-related processes and/or the contribution of magmatic volatiles are key for their enrichment. We present bulk sulfide, isotope (S and Pb), and high-resolution microanalytical data of hydrothermal sulfides from the Niua South fore-arc volcano in north Tonga, where numerous black-smoker type sulfide-sulfate chimneys emit boiling fluids with temperatures (up to 325°C) near the seawater boiling curve at ∼1170 m water depth. Hence, this system represents an ideal natural laboratory to investigate the effect of fluid boiling on base, precious, and volatile element enrichment associated with hydrothermal seafloor mineralization. At Niua South, textural and chemical variations of multiple pyrite (framboidal, euhedral and massive), chalcopyrite (linings), and sphalerite (dendrites and linings) generations are indicative for sulfide precipitation from early low-temperature (∼240°C) fluids that underwent abundant mixing with ambient seawater (low Se/Tl and Co/Ni ratios in pyrite) and from later high-temperature (up to 325°C) (high Se/Tl and Co/Ni ratios in pyrite). In addition, crustiform inclusion-rich pyrite that precipitated from high-temperature boiling fluids shows low Bi/Pb, Tl/Pb and Sb/Pb ratios due to volatile element loss (e.g., Tl and Sb) to the vapor phase compared to pyrite that formed during the low temperature stage. By contrast, late sphalerite (∼280°C) is enriched in elements with an affinity to Cl-complexes like Mn, Co, Ni, Ga, Cd, In, and Sn, and therefore precipitated from the corresponding Cl-rich liquid phase. Gold occurs in solid-solution and as boiling-induced particles of native Au, electrum, and Au-rich Bi-tellurides in pyrite (up to 144 ppm Au), sphalerite (up to 60 ppm Au), and chalcopyrite (up to 37 ppm Au). These particles (<5 – 10 µm) probably formed during fluid boiling causing an extreme Au enrichment (>30 ppm) in the mature and late stage of chimney formation. Lead isotope data indicate that the hydrothermal fluids scavenged metals not only from the deeper basement in the reaction zone (20 – 40 %), but also from young dacitic volcanic rocks near the seafloor in the upflow zone (60 – 80 %). Sulfur isotope (δ34S = -0.3 – 4.4 ‰) and Se/S*106 values (< 1500) of hydrothermal sulfides provide no evidence for a magmatic volatile influx and indicate that S, and most metals and semi-metals were likely leached from the host rocks. Hence, volatile (As, Se, Sb, Te, Tl), and precious (Au) element enrichments in arc-related submarine hydrothermal systems can be decoupled from magmatic volatiles and are instead a result of boiling-induced trace element fractionation – a hydrothermal enrichment process, which has been underestimated to date.<br

Effects of magmatic volatile influx in mafic VMS hydrothermal systems: evidence from the Troodos ophiolite, Cyprus - Martin, Andrew J.; Keith, Manuel; Parvaz, Daniel B.; McDonal, Iain; Boyce, Adrian J.; McFall, Katie A.; Jenkin, Gawen R. T.; Strauss, Harald; MacLeod, Christopher J. (Chemical Geology, 2020)
The Troodos ophiolite, Cyprus is the principal on- land analogue for mafic-hosted volcanogenic massive sulfide (VMS) deposits. This study, for the first time, presents sulfur isotope (δ34S) data on a regional scale from VMS deposits and other mineralised zones across the Troodos ophiolite. In combination δ34S, Se/S ratios and trace element chemistry (e.g., Se, Cu and Au) of different hydrothermal sulfides are used to assess variations in magmatic volatile influx and the source of metals and sulfur in ancient hydrothermal systems. Sulfur isotope analyses (n =180) across 19 mineral deposits indicate a variable source of sulfur in the Troodos VMS hydrothermal system, this in turn allows a variable source of metals to be inferred. Pyrite δ34S range from −5.5‰ to +13.2‰ with an average of +4.6‰ (n =160) for all deposits investigated. These δ34S variations cannot only be explained by variable proportions of thermochemical seawater sulfate reduction (δ34S +18 to +19‰) and leaching of primary magmatic sulfur from igneous rocks (δ34S 0-1‰). Consequently, two processes are proposed, explaining the trace metal and δ34S variation across the Troodos ore-forming systems including, i) a variable source of metals in the sheeted dyke complex and ii) the addition of a magmatic volatilerich phase to the VMS hydrothermal systems. Two distinct lava units exist in the Troodos stratigraphy, namely the upper and lower pillow lavas (UPL and LPL). The more primitive UPL are enriched in Au, Se and Cu relative to As, Sb and Zn that are concentrated in the LPL. Some VMS deposits pre-date the formation of the UPL (e.g., Agrokipia A) suggesting Se, Cu and Au depleted source rocks. Hence, the stratigraphic position of VMS deposits and the ratio of UPL:LPL affinity elements (e.g., As +Zn +Sb vs. Cu + Se+Au) imply a systematic relationship between trace element distribution and stratigraphic depth; this relates to the relative proportion of UPL and LPL affinity lavas within the metal source region. δ34S values<0‰ recorded in some VMS deposits that are less than the Troodos magmatic mean of 0- 1‰ may be related to anhydrite buffering during fluid ascent, microbial sulfate reduction or the direct contribution of magmatically derived sulfur, to the hydrothermal system from an underlying magma chamber via volatile exsolution. We propose that negative δ34S values combined with Se/S Å 106 ratios>500 in pyrite suggest the contribution of a magmatic volatile component (e.g., Apliki and Skouriotissa). We demonstrate that the source of metals and sulfur in the Troodos VMS hydrothermal system is affected by regional scale processes related to i) variable source lithologies and, ii) the contribution of a magmatic volatile phase to some Troodos VMS hydrothermal system

Effects of Raw Meal Substitution by Sewage Sludge on OPC Clinker studied by Rietveld Analysis - Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen (20th International Conference on Cement Microscopy, 1998)
UnivIS-Import:2015-03-05:Pub.1998.nat.dgeo.IGM.LM.effect

Effects of sulfate reduction processes on the trace element geochemistry of sedimentary pyrite in modern seep environments - Lin, Zhiyong; Sun, Xiaoming; Chen, Kaiyun; Strauss, Harald; Klemd, Reiner; Smrzka, Daniel; Chen, Tingting; Lu, Yang; Peckmann, Jorn (Geochimica Et Cosmochimica Acta, 2022)
Although it has been suggested that the trace element patterns of sedimentary pyrite can be affected by early diagenesis, detailed studies on modern marine environments addressing this hypothesis are scarce. Organoclastic sulfate reduction (OSR) and sulfate-driven anaerobic oxidation of methane (SD-AOM) are the dominant sulfate reduction processes in organic-rich and methane-rich marine sediments, and commonly result in the formation of authigenic pyrite. To better understand how OSR and SD-AOM affect the trace element geochemistry of pyrite, we applied laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) to analyze trace element contents of pyrite from two methane-seep sites (DH-CL11 and HS148) of the South China Sea. The trace element data are complemented by the measurement of iron isotope compositions of authigenic pyrite. This new data set, supplemented by published sulfur isotope data, improves our understanding of the diagenetic processes during early diagenetic pyrite formation. High δ56Fe and δ34S values of pyrite reflect the dominance of SD-AOM within sulfate-methane transition zones (SMTZs) at both sites (i.e., from 705 to 767 cm below seafloor at site DH-CL11 and from 490 to 690 cm below seafloor at site HS148), whereas pyrite from shallow depth characterized by low δ56Fe values points to early OSR processes. Within the SMTZs, pyrite exhibits highly variable but overall high manganese (Mn) contents (12 to 732 mg/kg at site DH-CL11; 12 to 1145 mg/kg at site HS148), compared to OSR-derived pyrite from shallow depth. Similar to this pattern, pyrite formed at the SMTZ shows higher lead (Pb), zinc (Zn), copper (Cu), and vanadium (V) contents than pyrite formed at shallower depths above the SMTZ. Enrichments of these metals in pyrite forming at the SMTZ are best explained by enhanced reductive dissolution of iron and manganese (oxyhydr)oxides under sulfidic conditions induced by SD-AOM, and subsequent trace element incorporation into pyrite. Arsenic (As), molybdenum (Mo), and antimony (Sb) distributions in pyrite vary between the two study sites. Pyrite from shallow depth of site HS148 has high contents of all three elements, indicating effective immobilization of dissolved As, Mo, and Sb during pronounced OSR. In contrast, apparently less intense OSR at shallow depth of site DH-CL11 allowed for more dissolved As, Mo, and Sb to diffuse downward to greater depth, resulting in the enrichments of these elements in pyrite formed at or close to the SMTZ. Positive correlations between As and cobalt (Co), and between As and nickel (Ni) typify pyrite derived from both OSR and SD-AOM for both study sites, and As-rich pyrite from site DH-CL11 is characterized by a distinctly high Co/Ni ratio. Both patterns suggest that the presence of As affects the uptake of Co and Ni into pyrite. Our study documents that pyrite element contents in methane-rich environments are significantly influenced by different sulfate reduction processes during early diagenesis, allowing the differentiation of OSR-derived pyrite from SD-AOM-derived pyrite by means of trace element geochemistry.
CRIS-Team Scopus Importer:2022-08-12
Keywords: Authigenic pyrite; Organoclastic sulfate reduction; Seawater geochemistry; Sulfate-driven anaerobic oxidation of methane; Trace elements

Effects of temperature, sulfur, and oxygen fugacity on the composition of sphalerite from submarine hydrothermal vents - Keith, Manuel; Haase, Karsten; Schwarz-Schampera, Ulrich; Klemd, Reiner; Petersen, Sven; Bach, Wolfgang (Geology, 2014)
Experimental studies have shown that temperature, pressure, sulfur fugacity (fS2), and oxygen fugacity (fO2) influence the Fe content of sphalerite. We present compositional in situ data on sphalerite from submarine volcanic-hosted massive sulfide (VHMS) ores of hydrothermal vents from different plate tectonic settings and with variable host-rock compositions. Sphalerite from sediment-hosted vents has systematically higher S contents and Fe/Zn ratios than those of the sediment-starved vents, reflecting an influence of fS2 and fO2 on Fe partitioning between fluid and sphalerite. The Fe/Zn ratios of sphalerite from sediment-starved vent systems apparently increase systematically with the fluid temperatures of the corresponding vents. We conclude that the composition of sphalerite can be used to (1) distinguish between sediment-hosted and sediment-starved hydrothermal processes, and (2) estimate minimum fluid temperatures of sphalerite precipitation from inactive sediment-starved hydrothermal vent sites and fossil VHMS deposits. © 2014 Geological Society of America.
UnivIS-Import:2015-04-14:Pub.2014.nat.dgeo.IGM.c3geoc.effect

Effects of the Hydrous Domain in the Mantle Wedge on Magma Formation and Mixing at the Northeast Lau Spreading Center, SW Pacific - Haase, Karsten; Schönhofen, Milena; Storch, Bettina; Beier, Christoph; Regelous, Marcel; Rubin, Kenneth H.; Brandl, Philipp A. (Geochemistry Geophysics Geosystems, 2022)
Keywords: back-arc spreading; Lau Basin; Tofua island arc; lithosphere rifting; slab component

Effects of two oppositely charged colloidal polymers on cement hydration - Lu, Zichen; Kong, Xiangming; Zhang, Chaoyang; Jansen, Daniel; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (Cement & Concrete Composites, 2019)
Keywords: Nucleation; Polymer latex; Cement hydration; Ionic charge; Adsorption

Effects of variable slab components and tectonics on magma composition in the intra-oceanic Kermadec Arc-Backarc system - Myeong, Bora; Regelous, Marcel; Haase, Karsten; Münker, C. (Chemical Geology, 2023)
The Kermadec Arc-Backarc system (25–39°S) in the southwest Pacific is an important natural laboratory to examine the controls on arc magma compositions, because the physical parameters that are thought to influence subduction-related magmatism (the thickness and composition of the upper plate, mantle depletion and partial melting, and the slab components) change along the arc. Furthermore, the presence of back-arc and rear-arc volcanism allow insight into how mantle composition varies with distance to the trench. We present new major and trace element and Pb–Sr–Nd–Hf isotope data for 101 lava samples from 10 volcanoes along the Kermadec Arc, and combine these with published data for volcanic arc front, rear-arc, and back-arc lavas. The Kermadec Arc-Backarc magmas experienced similar fractional crystallization paths, and those erupted onto oceanic crust are not affected by crustal assimilation. The degree of partial melting varies along and across the arc, partly due to variations in the thickness of the lithosphere of the upper plate, but also due to variations in slab fluid input. We distinguish four different arc segments varying from 100 to 600 km wide, which erupt lavas with distinct compositions due to differences in along-arc slab input. All Kermadec arc and rear-arc lavas were derived from mantle sources to which the sediment melt and a fluid from subducted Pacific oceanic crust or the Hikurangi Seamounts had been added. Increasing sediment melt input into the mantle wedge southwards is reflected in increasing 87Sr/86Sr and Th/Nd, and decreasing 143Nd/144Nd southwards towards New Zealand. Some volcanoes from the central Kermadec Arc show with unusually radiogenic Pb isotope compositions that are probably derived from subducted alkaline rocks from seamounts built on the Hikurangi Plateau. The geochemical segmentation of the Kermadec Arc indicates that slab-derived components can be relatively homogeneous on large scales, but small features like seamounts cause complex additions to the slab component.
CRIS-Team Scopus Importer:2022-12-23
Keywords: Kermadec Arc-Backarc system; Mantle depletion; Partial melting; Subduction input; Hikurangi Seamounts; The geochemical variation along and across the arc

Effects of volume on travel distance of mass movements triggered by the 2005 Kashmir earthquake, in the Northeast Himalayas of Pakistan - Basharat, Muhammad; Rohn, Joachim (Natural Hazards, 2015)
Keywords: Fahrböschung angle; Kashmir earthquake; Mass movement; Travel distance; Volume

Efficiency of highly sensitive heat flow calorimetry in examination of OPC hydration - Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (Proceedings of the 24th International Conference on Cement Microscopy, 2002)
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.LM.effici

Efflorescence during the drying of a technical gypsum body: Application of thermodynamic principles - Fobbe, Nicholas; Götz-Neunhoeffer, Friedlinde; Foerster, H.; Foerthner, S.; Jansen, D. (Construction and Building Materials, 2021)
The drying process of a technical flue gas desulphurization (FGD) gypsum body was studied. At low surface-to-volume ratios, it showed a significant efflorescence of hexahydrite (MgSO4·6H2O) after less than one day. A countermeasure against this phenomenon is the addition of small amounts of Ordinary Portland Cement (OPC) (0.2 wt%). Prisms of pure FGD and FGD-OPC mixtures were synthesized and investigated with a combination of 1H-TD-NMR and ICPMS measurements to monitor both the physical water content during the drying process and the chemical pore water composition within the first 48 h. The experiments showed no differences in the drying rate and pore water distribution and only small differences in the pore water composition. In combination with thermodynamic calculations, the prevention of efflorescence could be attributed to chemical processes in the pore water. Mg-sulfates potentially can form on both samples with the same chance. Therefore, it was concluded that OPC can only hinder efflorescence indirectly by decreasing the Mg concentration in the pore water. An increase in pH can cause Mg-phases to precipitate, thereby binding the Mg before Mg-sulfates can form on the surface of the body. Further calculations revealed, that the two phases hydrotalcite and M−S−H can potentially form inside the FGD-OPC prism, probably due to an increase of the pH.
CRIS-Team Scopus Importer:2021-08-27
Keywords: Drying process; Efflorescence; Gypsum; Solubility; Thermodynamic calculation

Einbau von Schwermetallen in Silikatapatite - Neubauer, Jürgen; Pöllmann, Herbert (European Journal of Mineralogy, 1990)
UnivIS-Import:2015-03-05:Pub.1990.nat.dgeo.IGM.LM.einbau

Ein "Dropstone" im Belemnitenschlachtfeld von Mistelgau - Schulbert, Christian (Geologische Blätter für Nordost-Bayern und angrenzende Gebiete, 2008)
UnivIS-Import:2015-03-09:Pub.2008.nat.dgeo.IGM.LP.eindro

Einfluss Ca-reicher Additive in Verbindung mit Li2CO3 auf das Hydratationsverhalten von Monocalciumaluminat - Enderle, Ralph; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (GDCh-Monographien, 2004)
UnivIS-Import:2015-03-09:Pub.2004.nat.dgeo.IGM.LM.einflu_4

Einfluss der Präparationstechnik auf den Wärmefluss bei der Hydratation eines Portlandzementes - Schmitt, Dirk; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde; Degenkolb, Matthias; Holland, Uwe (GDCh-Monographie Bauchemie, 2004)
UnivIS-Import:2015-03-09:Pub.2004.nat.dgeo.IGM.LM.einflu_1

Einfluss des Alits auf die Anfangshydratationswärme von Portlandzementen - Steinert, Susanne; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (GDch Monographien, 2005)
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LM.einflu

Einführung in die Angewandte Mineralogie - Goetze, Jens; Göbbels, Matthias (2017)
Im geplanten Lehrbuch werden insbesondere Bachelor-Studenten der Geo- und Materialwissenschaften wichtige stoffliche und technologische Grundlagen in verschiedenen technischen Systemen und angewandten geowissenschaftlichen Bereichen vermittelt. Ausgehend von der Mineralogie ausgewählter nichtmetallischer Rohstoffe und Industrieminerale werden Zusammenhänge zwischen Eigenschaften und industriellen Einsatzmöglichkeiten dargelegt sowie umweltrelevante Aspekte diskutiert. Eine Einführung erfolgt in wichtige mineralogische und physikalisch-chemische Aspekte technischer keramischer Massenprodukte wie Silikatkeramik, Glas, Zement, Feuerfestmaterialien oder der Mineralsynthese.<br
Keywords: Mineralogie; Mineralsynthese; Nichtmetallische Rohstoffe; Silikatische Wekstoffe; Umweltmineralogie

Eklogite des Erzgebirges - Schmädicke, Esther; et al. (European Journal of Mineralogy, 1990)
UnivIS-Import:2017-03-24:Pub.1990.nat.dgeo.IGM.profes_1.eklogi

Electrical Conductivity in BaTi1-xFexO3-d system - Göbbels, Matthias; Hock, Rainer; Magerl, Andreas; Mashkina, Elena; Demin, A.G.; et al. (Proceeding of Fifth European Solid Oxide Fuel Cell Forum, 2002)
UnivIS-Import:2015-04-16:Pub.2002.nat.dphy.IAP.LK.electr_32

Elemental systematics of the calcitic skeleton of Corallium rubrum and implications for the Mg/Ca temperature proxy - Chaabane, S.; López Correa, Matthias; Ziveri, P.; Trotter, J.; Kallel, N.; Douville, E.; McCulloch, M.; Taviani, M.; Linares, C.; Montagna, P. (Chemical Geology, 2019)
The high-Mg calcite skeleton of Corallium rubrum was analyzed from living colonies collected from a wide range of depths (15 m to 607 m) and environmental settings in the Mediterranean Sea. An overarching goal was to better understand the calcification process and incorporation of elements into the slow-growing skeleton of both shallow and deep-water specimens, and more specifically, to clarify the veracity of geochemical proxies for reconstructing seawater temperatures. The coral internal structure including growth bands were determined by scanning electronic microscopy (SEM) and petrographic techniques. Trace elements (Li, B, Mg, Sr and Ba) compositions of the coral skeleton were obtained by solution and laser ablation inductively coupled plasma mass spectrometry (ICP-MS). Results show that the skeleton of the deep-water specimens has an internal microstructure similar to shallow-water colonies, with the medullar and the annular zones clearly distinguishable in both shallow and deep-water specimens. In general, the bands of the deep-water samples are very thin and equidistant compared to the irregular banding of the shallow-water specimens. Banding differences relate to the contrasting environmental dynamics, with the shallow-water specimens being exposed to large seasonal fluctuations compared to the relative stable conditions of those inhabiting bathyal depths. The inner medullar and outer annular portions differ in their trace element concentrations: Mg/Ca, Sr/Ca and Li/Ca ratios are higher in the medullar zone and seem to be influenced by growth kinetics, whereas B/Ca and Ba/Ca are similar in both zones and hence unaffected by growth rate. The variability of elemental ratios is lower in the deep-water specimens. Growth bands are highly correlated to Mg/Ca, Sr/Ca and Li/Ca, suggesting common mechanism(s) controlling the incorporation of these elements into the coral skeleton. Mg/Ca ratios were especially depleted in the dark bands. Although the mean Mg/Ca of each specimen is positively correlated to ambient seawater temperature, the intra-annual variations and amplitudes differ and do not correlate to the band widths. These findings suggest that intra- and inter-annual variations of Mg/Ca cannot be used to reconstruct a continuous time-series of long-term seasonal temperature records. However, the mean Mg/Ca composition can serve as a valuable proxy to estimate mean palaeoseawater temperature at a given site within the Mediterranean.
CRIS-Team Scopus Importer:2019-07-16
Keywords: Calcite skeleton; Corallium rubrum; Growth bands; Mediterranean Sea; Red coral; Temperature proxy; Trace elements

Element partitioning in magnetite under low-grade metamorphic conditions – a case study from the Proterozoic Belt Supergroup, USA - Nadoll, Patrick; Mauk, Jeffrey L.; Hayes, Timothy S.; Koenig, Alan E.; Box, Stephen E. (European Journal of Mineralogy, 2017)
The distribution and partitioning of elements in igneous rocks is well established for various melt–(fluid)–solid pairs and provides important insights into the petrogenesis of these rocks. Studies of the partitioning behavior of elements under metamorphic conditions are scarce and commonly focus on high-grade metamorphic facies. Little is known about the partitioning behavior of elements under low-grade metamorphic conditions. Greenschist-facies metasedimentary rocks of the North American Belt Supergroup host magnetite that displays equilibrium features with co-existing mineral phases such as quartz and carbonate. Magnetite is an ideal target for geochemical investigations because it can incorporate a large number of cations and is sensitive to changes in temperature, oxygen fugacity, pressure, whole-rock composition, and cooling trends. Whole-rock major and trace element analyses have been undertaken on representative samples from Belt Supergroup metasedimentary rocks using X-ray fluorescence. Electron microprobe and laser ablation ICP-MS were used to obtain major and trace element concentrations for magnetite hosted in these rocks. Stable-isotope geothermometry of magnetite–quartz and magnetite–carbonate pairs constrain metamorphic temperatures to <span style="color: rgb(0, 0, 0); font-family: inherit; font-size: inherit; -webkit-font-smoothing: antialiased; margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; font-style: italic; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit;">ca. 390 °C. Partition coefficients (<span style="color: rgb(0, 0, 0); font-family: inherit; font-size: inherit; -webkit-font-smoothing: antialiased; margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; font-style: italic; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit;">D) for magnetite–matrix pairs presumably reflect equilibrium at these low-grade metamorphic conditions. <p id="p-3" style="-webkit-font-smoothing: antialiased; margin: 0px 0px 17px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; font-family: "PT Sans"; font-size: 14px; font-stretch: inherit; line-height: inherit; word-wrap: break-word; color: rgb(0, 0, 0);"> Except for Mn and Ni, which show comparable partition coefficients, the calculated values are one to two orders of magnitude lower than those for igneous magnetite. Aluminum displays the lowest calculated partition coefficient with a value of 0.006 and Ni and Fe the highest values with 6.3 and 20.9, respectively. Of the elements that commonly occur in spinel-group minerals, two groups can be distinguished: (1) elements that preferentially partition into the host rock (<span style="-webkit-font-smoothing: antialiased; margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; font-family: inherit; font-size: inherit; font-style: italic; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit;">D < 1): Al, Mg, Pb, and Ti and (2) elements that show a preference to partition into magnetite (<span style="-webkit-font-smoothing: antialiased; margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; font-family: inherit; font-size: inherit; font-style: italic; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit;">D > 1): Zn, Mn, Cr, V, Ni, and Fe.

Elevation-driven ecological isolation promotes diversification on Mediterranean islands - Steinbauer, Manuel; Irl, Severin; Beierkuhnlein, Carl (Acta Oecologica-International Journal of Ecology, 2013)
The percentage of single island neo-endemic species (an indicator for evolutionary diversification) was found to be independent of geographic distance to the continent in the case of the Aegean archipelago. It was concluded that speciation is independent of geographic isolation, while evolutionary processes are rather enhanced by habitat heterogeneity. An island's maximum elevation was used as an indicator for habitat heterogeneity. In contrast, we argue that habitat heterogeneity (= habitat diversity, i.e. the richness in different habitats) may be positively related to biotic richness, but a positive effect on speciation is yet to be proven. For any other type of heterogeneity, we propose a precise wording, especially when assessing its effect on speciation processes. Alternatively, we propose that elevation-driven ecological isolation causes the pattern of endemic species on high-elevation islands. Environmental filtering along an elevational gradient differentiates ecosystems, leading to an increase of isolation with elevation. The reason is that comparable ecosystems are much farther apart than is the case for lowland ecosystems. In addition, ecosystems on neighboring islands or on the continent that may be source regions for colonizing species are small in area in high elevations in comparison with low elevation ecosystems. Consequently, an increased speciation rate resulting in a larger percentage of single island endemic species can be expected for higher elevations on islands and high mountains. Support for this elevation-driven ecological isolation hypothesis comes from other islands in the Mediterranean region (e.g. Crete and Corsica), where an increase of the percentage of endemic species with elevation has been observed. Thus, the assessment of (genetic-) isolation should incorporate the distance to similar habitats instead of simple land-to-land connections.
Keywords: Crete; Environmental filter; Habitat diversity; Habitat heterogeneity; Island biogeography; Neo-endemic; PSIE; Single island endemic species; Speciation

Ellesmerian and Eurekan fault tectonics at the northern margin of Ellesmere Island (Canadian High Arctic) - Piepjohn, Karsten; von Gosen, Werner; Laeufer, Andreas; Mcclelland, William C.; Estrada, Solveig (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 2013)
Keywords: Ellesmere island; Eurekan deformation; Ellesmerian orogeny; Pearya terrane; North margin of north america; Plate tectonics

Emergence patterns of locally novel plant communities driven by past climate change and modern anthropogenic impacts - Staples, Timothy L.; Kießling, Wolfgang; Pandolfi, John M. (Ecology Letters, 2022)
Anthropogenic disturbance and climate change can result in dramatic increases in the emergence of new, ecologically novel, communities of organisms. We used a standardised framework to detect local novel communities in 2135 pollen time series over the last 25,000 years. Eight thousand years of post-glacial warming coincided with a threefold increase in local novel community emergence relative to glacial estimates. Novel communities emerged predominantly at high latitudes and were linked to global and local temperature change across multi-millennial time intervals. In contrast, emergence of locally novel communities in the last 200 years, although already on par with glacial retreat estimates, occurred at midlatitudes and near high human population densities. Anthropogenic warming does not appear to be strongly associated with modern local novel communities, but may drive widespread emergence in the future, with legacy effects for millennia after warming abates.
CRIS-Team Scopus Importer:2022-05-20
Keywords: anthropogenic warming; dispersal; fossil pollen assemblage; glacial retreat; human impacts; novel ecosystems; post-glacial warming; quaternary; temperature change

Empirical calibration of the clumped isotope palaeothermometer using calcites of various origins. - Wacker, Ulrike; Fiebig, Jens; Toedter, Julian; Schoene, Bernd R.; Bahr, Andre; Friedrich, Oliver; Tuetken, Thomas; Gischler, Eberhard; Joachimski, Michael (Geochimica Et Cosmochimica Acta, 2014)
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LG.empiri

Empirical modeling of maps of geo-exchange potential for shallow geothermal energy at regional scale - Zarrella, Angelo; de Carli, Michele; Di Sipio, Eloisa; Chiesa, Sergio; Destro, Elisa; Teza, Giordano; Galgaro, Antonio; Emmi, Giuseppe; Manzella, Adele (Geothermics, 2015)
Keywords: Shallow geothermal energy; Vertical borehole heat exchanger; Ground source heat pump; Geo-exchange potential; GIS

Emsian Ammonoidea and the age of the Hunsruck Slate (Rhenish Mountains, Western Germany) - de Baets, Kenneth; Klug, Christian; Korn, Dieter; Bartels, Christoph; Poschmann, Markus (Palaeontographica Abteilung A-Palaozoologie-Stratigraphie, 2013)
The ammonoids from the well-studied German Fossillagerstatte of the Hunsruck Slate have the reputation of being the oldest known representatives of this cephalopod group. This material is of great interest not only because of the global scarcity of the earliest ammonoids, but also because it includes the first record of stratigraphically-controlled specimens, which could be assigned to the middle Kaub Formation in the Bundenbach/Gemunden area. Accordingly, some of the Hunsruck Slate ammonoids are indeed the stratigraphically oldest ammonoids because they are associated with the index dacryoconarid Nowakia praecursor and thus derive from the Nowakia zlichovensis Biozone of the early Emsian (Zlichovian), while younger dacryoconarids and other ammonoid samples (Mimagoniatites fecundus, Mimosphinctes tripartitus) indicate the Nowakia barrandei to N elegans biozones. In spite of this special importance, these Early Devonian cephalopods have never been revised comprehensively. Our study includes more than 300 Hunsruck Slate specimens from both public and private collections. For the first time, ammonoids from the Altlay Hunsriick Slate in the Northern Hunsruck/Mosel region are reported, while all the materials from older collections derive from the middle Kaub Formation of the Central Hunsriick Basin (central Hunsriick, Taunus). These early ammonoids thus prove to be a valuable source of information for biostratigraphic correlation within the Hunsriick Slate and with early Emsian occurrences in other regions. Based on conch characters (geometry, ornament, suture lines) and ontogenetic traits, we describe the species Metabactrites fuchsi n. sp., Ivoites hunsrueckianus (ERBEN 1960), Ivoites schindewolfi n. sp., ?Ivoites sp., Ivoites opitzi n. sp., Anetoceras mittmeyeri n. sp., Erbenoceras advolvens (ERBEN 1960), Erbenoceras solitarium (BARRANDE 1865), Chebbites sp., Mimosphinctes primigenitus (ERBEN 1965), Mimosphinctes tripartitus EICHENBERG, 1931, Gyroceratites heinricherbeni n. sp., ?Teicherticeras sp., and Mimagoniatites fecundus (BARRANDE 1865). Supposedly endemic species of the Hunsriick Slate such as "Anetoceras recticostatum ERBEN, 1962" and "Mimagoniatites falcistria (FucHs 1915)" are here synonymized with the widely distributed species Erbenoceras solitarium and Mimagoniatites fecundus, both known to occur also outside Europe. Furthermore, we studied their taphonomy and assigned them to seven groups of preservation. The results of this taphonomic study corroborate previous interpretations of the depositional environment and diagenesis. We also discuss the evolution of the shell in the earliest ammonoids and their closest relatives as well as structures ("Opitzian pits") possibly caused by parasitic infestations of these early Emsian ammonoids.
Keywords: Ammonoidea; Hunsriick Slate; Early Devonian; systematics; biostratigraphy; taphonomy; macroevolution; paleoecology; parasite; pearl

Endemism increases species' climate change risk in areas of global biodiversity importance - Manes, Stella; Costello, Mark J.; Beckett, Heath; Debnath, Anindita; Devenish-Nelson, Eleanor; Grey, Kerry Anne; Jenkins, Rhosanna; Khan, Tasnuva Ferdous Ming; Kießling, Wolfgang; Krause, Cristina; Maharaj, Shobha S.; Midgley, Guy F.; et al. (Biological Conservation, 2021)
Climate change affects life at global scales and across systems but is of special concern in areas that are disproportionately rich in biological diversity and uniqueness. Using a meta-analytical approach, we analysed >8000 risk projections of the projected impact of climate change on 273 areas of exceptional biodiversity, including terrestrial and marine environments. We found that climate change is projected to negatively impact all assessed areas, but endemic species are consistently more adversely impacted. Terrestrial endemics are projected to be 2.7 and 10 times more impacted than non-endemic natives and introduced species respectively, the latter being overall unaffected by climate change. We defined a high risk of extinction as a loss of >80% due to climate change alone. Of endemic species, 34% and 46% in terrestrial and marine ecosystems, and 100% and 84% of island and mountain species were projected to face high extinction risk respectively. A doubling of warming is projected to disproportionately increase extinction risks for endemic and non-endemic native species. Thus, reducing extinction risks requires both adaptation responses in biodiversity rich-spots and enhanced climate change mitigation.
CRIS-Team Scopus Importer:2021-05-14
Keywords: Biodiversity hotspots; Extinction risk; Global-200 ecoregions; Introduced species

Endolithic bioerosion in cephalopods from the upper Carboniferous Buckhorn Asphalt Quarry Lagerstätte (Oklahoma, USA) - Seuß, Barbara; Nützel, Alexander (9th International Bioerosion Workshop, 2017)
Deposits of the Pennsylvanian (upper Carboniferous) Buckhorn Asphalt Quarry in southern Oklahoma, USA, are of mixed siliciclastic-carbonatic composition; however,crucial is the high content of hydrocarbons, that intruded the sediments during or onlyshortly after deposition. These hydrocarbons impregnated not only the deposits but more important, the fossils within. The result of this intense soaking with hydrocarbons, that altered into asphalt afterwards, was an upper Carboniferous (Pennsylvanian) Lagerstätte of outstanding quality; e.g., preservation of delicate shell ornamentation and juvenile shells, preservation of color patterns on naticopsids, as well as original shell microstructure and mineralogy in different taxa (Bandel et al. 2002; Seuss et al. 2009, 2012a, b; Ernst et al. 2016). In addition, the fauna is high diverse with approximately 150 different taxa reported so far (Seuss et al. 2009). Many shells show intense bioerosion on their surface and borings are also well visible in thin sections. In an earlier study on the Buckhorn bioeroders Wisshak et al. (2008) studied and interpreted the ichnocenosis present in Buckhorn fossils. The study was mainly based on gastropod and bivalve shells and yielded an assemblage of 18 known and one new ichnospecies. The ichnocoenosis was the most diverse record of ichnotaxa of that age and contains 13 first, including nine oldest, appearances for the Carboniferous (Wisshak et al. 2008, Table 2) and it represents the shallow euphotic zone II–III following the ichnobathymetric scheme of Glaub (1994) and Vogel et al. (1995). Because the first study focussed on shallow marine, benthic organisms (i.e., gastropods, bivalves) a second study was performed recently to investigate shells ofnektonic taxa that are more prone to transportation after death of the animal. These are, for the study, orthoconic and coiled nautiloids and ammonoids (goniatites). The shells derive from a coquina that represents the deepest section of a cyclotheme that comprises the Buckhorn Asphalt Quarry’s deposits (compare Seuss et al. 2009, Fig. 6). In total 32 remains of orthoconic and 28 remains of the shells of coiled nautiloids and ammonoids are included in this analysis. Synthetic resin casts were prepared and preliminary results prove the presence of 25-30 ichnotaxa. Compared to studies on recent Nautilus (Seuss et al. 2015a, b, 2016) diversity is similar; however, the taxa differ distinctly. In the Buckhorn cephalopods representatives of the cyanobacteria are most diverse and most abundant, in orthoconic specimens, are the chlorophyte trace Ichnoreticulina elegans and a new ichnospecies of Scolecia (produced by cyanobacterium?) while in coiled cephalopods Flagrichnus profundus (produced by the fungus Schizochytrium sp.) and for ms of ‘very thin’ / ‘super thin’ traces dominate the association (rhodophyte / unknown heterotroph). A minimum of two ichnotaxa is reported for the first time; this number might be extended by so far unidentified traces of presumable foraminiferan origin. Despite the high diversity of traces, no ichnocoenosis was identified that would help in the identification of the relative bathymetry of the deposits and their fossil remain

End-Wenlock terminal Mulde carbon isotope excursion in Gotland, Sweden: Integration of stratigraphy and taphonomy for correlations across restricted facies and specialized faunas - Jarochowska, Emilia; Bremer, Oskar; Pröpster, Stephanie; Heidlas, Daniel; Vandenbroucke, Thijs R.A.; Munnecke, Axel (Palaeogeography, Palaeoclimatology, Palaeoecology, 2016)
The decline of the upper peak of the Homerian Mulde carbon isotope excursion (CIE) is used in low- to mid-paleolatitudes as a marker for the Wenlock/Ludlow boundary, which is otherwise difficult to constrain in carbonate successions. In the Midland Platform (England) the CIE ends just below the boundary or ranges through it, whereas in Baltic sections it has been placed substantially below the inferred base of the Ludlow Stage. Difficulties in correlating the Baltic sections are caused by widespread development of lagoons and sabkhas with specialized conodont and vertebrate faunas. We describe here a lagoonal section from Gothemshammar, eastern Gotland (Sweden), spanning the entire upper peak of the Mulde CIE. Based on integrated conodont, δC and sequence stratigraphy, a hardground present at the lowering limb of the CIE is correlated with a sequence boundary present across the Baltic Basin, in the Midland Platform, and the southern shelf of Laurentia. This sequence boundary corresponds to a global eustatic regression and can serve as a correlative horizon in restricted facies with depauperate or specialized fauna. The Wenlock-Ludlow boundary is placed in the transgressive strata overlying this boundary. Species richness and abundance of thelodonts, anaspids, and osteostracans at Gothemshammar represent one of the first diversity peaks of vertebrates in the Silurian. Associated conodonts are characteristic for late Wenlock marginal-marine environments and distinguished by large, robust elements. We quantitatively assess the conodont assemblages to evaluate to which degree the overrepresentation of large elements in these facies is produced by taphonomic processes. The taphonomic alteration differs between species and facies, but is lowest for the shallow-water specialist Ctenognathodus murchisoni. Regardless, the use of this species as an index taxon is discouraged based on its strong facies affinity. Instead, the integrated approach proposed here indicates that the Wenlock/Ludlow boundary is situated lower in the Baltic sections than previously identifie
Keywords: Conodont; Deformation; Fish; Palynomorph; Taphonomy; Vertebrate

Energy Balance And Body Composition In Elite Alpine Skiers During Training At Altitude And Across The Competitive Season - Engel, Helena; Martin, Alexandra; Hofmann, Hande; van Geldern, Robert; Wasserfurth, Paulina; Halle, Martin; Wimbauer, Fritz; Koehler, Karsten (MEDICINE & SCIENCE IN SPORTS & EXERCISE, 2022)
CRIS-Team WoS Importer:2022-12-23

Enforced Symmetry: The Necessity of Symmetric Waxing and Waning - Hohmann, Niklas; Jarochowska, Emilia (PeerJ, 2019)
A fundamental question in ecology is how the success of a taxon changes through time and what drives this change. This question is commonly approached using trajectories averaged over a group of taxa. Using results from probability theory, we show that averaged trajectories will be more symmetric as the number of averaged trajectories increases, even if none of the original trajectories they were derived from is symmetric. This effect is not only based on averaging, but also on the introduction of noise and the incorporation of a priori known origination and extinction times. This implies that averaged trajectories are not suitable for deriving information about the processes driving the success of taxa. In particular, symmetric waxing and waning, which is commonly observed and interpreted to be linked to a number of different paleobiological processes, does not allow drawing any conclusions about the nature of the underlying process. We present a nonparametric test that avoids the problems introduced by averaging and allows to test hypotheses regarding the success of taxa through time.<br
Keywords: Symmetry; Ecology; Limit theorems; Range size; Occupancy; Diversity; Extinction risk; Nonparametric statistics; Ordination; Averaging; Stochastic process

Enhanced alite dissolution by CAH10 addition - Becker, Franz; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen (Cement and Concrete Research, 2023)
The influence of varying Al addition in the form of CAH10 on the hydration of alite was studied to gain further insights into the alite hydration mechanisms in the presence of increased Al concentration in pore solution. Therefore, pure alite and mixtures of alite and CAH10 were investigated by means of isothermal heat flow calorimetry, XRD and pore solution chemistry analysis. The two occurring hydration events can be attributed to the precipitation of two different silicate-bearing hydrate phases, C2ASH8 and C-(A)-S-H. In this case, the consumption and removal of Al in pore solution initiated the change to C-(A)-S-H-forming hydration. Furthermore, the formation of C2ASH8 and the alite reaction rate and reaction were directly influenced by the amount of Al provided by CAH10 addition, leading to an alite reaction turnover of up to 68–86 % within 48 h.
CRIS-Team Scopus Importer:2023-01-06
Keywords: Ca3SiO5 (D); Hydration (A); Hydration products (B); Pore solution (B); X-ray diffraction

Enhancing seal quality prediction by modelling spatial permeability distributions of meter-scale fine-grained sediments. - Drews, Michael; Kurtev, Kuncho; Böker, Ulf; Ma, Jingsheng; Aplin, Andrew; et al. (Geological Society Meeting: Modelling Sedimentary Basins and their Petroleum Systems, 2010)

Enhancing the aluminate reaction during OPC hydration by combining increased sulfate content, triethanolamine and tartaric acid - Kirchberger, Irina; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen (Cement and Concrete Research, 2023)
Possibilities for enhancing the aluminate reaction were studied in a mix of OPC blended with 7.9 % hemihydrate (HH) or 7.4 % anhydrite (AH) in combination with different triethanolamine (TEA) dosages. Heat flow calorimetry and quantitative X-ray diffraction (XRD) were performed to study the hydration process. Using anhydrite as an additional sulfate carrier allowed a lower TEA dosage compared to hemihydrate systems to enhance the degree of hydration of C3A. High TEA dosages in hemihydrate systems were found to hinder C3S hydration. Nevertheless, it was possible to push the aluminate reaction ahead of the silicate reaction, thereby enhancing the degree of hydration of C3A. Additionally, the degree of hydration of C3S was not strongly affected when anhydrite and a well-balanced TEA dosage were used. The addition of tartaric acid to OPC-anhydrite-TEA systems retarded the subsequent aluminate reaction.
CRIS-Team Scopus Importer:2023-05-12
Keywords: Acceleration (A); Admixture (D); Ca; Hydration (A); Retardation (A)

Enigmatic encrusting fossils from the Upper Devonian of Russia: probable Rothpletzella microproblematica preserved in three dimensions - Zatoń, Michał; Jarochowska, Emilia (Historical Biology, 2018)
Intriguing microfossils encrusting certain Upper Devonian brachiopod shells from the Central Devonian Field, Russia, are reported for the first time. The fossils are pyritized, have fan-shaped morphologies and are formed by tightly-packed branches which divide dichotomously at different points in their development. The organisms preserved grew horizontally on shelly substrates. Comparisons with similar fossils known from the literature indicate that they do not represent any animal taxon commonly encrusting hard substrates. Instead, the morphology, organization and growth mode of these fossils are most similar to microfossils known under the name Rothpletzella, which so far have only been known from thin sections. Rothpletzella is a problematicum for which algal affinities have been proposed. The preserved branches of the fossils described here are too large for cyanobacterial cells. Their large size suggests their placement, along with other described Rothpletzella fossils, within the green algae order Bryopsidales. It is suggested that originally, these organisms possessed thalli encased within a thin, delicate calcified sheath. After burial the thalli underwent pyritization via sulphate reduction mediated by bacterial activity within low pH, dysoxic microenvironment, and their sheath dissolved. As three-dimensionally preserved, these algae provide a new, previously unrecognized, component within the Devonian encrusting communitie
Keywords: Epibionts; Frasnian; algae; pyritization; palaeoecology

Enrichment of H2O and fluid-soluble trace elements in the Troodos Ophiolite: Evidence for a near-trench origin - Wölki, Dominic; Michael, Peter; Regelous, Marcel; Haase, Karsten (Lithos, 2020)
The Troodos Ophiolite on the island of Cyprus is a Cretaceous supra-subduction zone ophiolite. It formed by seafloor spreading in the vicinity of a subduction zone, but the exact tectonic setting in which it formed is debated. We determined H2O contents together with other volatiles (S, Cl and CO2) and Sr, Nd and Pb isotope compositions of fresh Troodos volcanic glasses, previously measured for major and trace element contents. Glass compositions range from boninite to tholeiitic andesite. The least degassed glasses have H2O contents of 1.7 to 2.7 wt%, and H2O/Ce ratios of 4400 to 33,600. The most depleted glasses with low Zr/Yb have the highest fractionation-corrected H2O contents and H2O/Ce, and the highest subduction zone input (highest Th/La, Ba/Zr and Sr-87/Sr-86). The high H2O contents, enrichment in fluid-mobile elements, and depletion in Zr, Hf and heavy rare-earth elements are consistent with formation above a subduction zone, very close to a trench in a fore-arc position, likely at water depths of -5000 m. The enrichment in both fluid-mobile (e.g. Rb, Cs) and melt soluble (e.g. Th) elements indicate that the Troodos Ophiolite formed by propagation of a back-arc rift into the forearc region of an active subduction zone. (C) 2019 Elsevier B.V. All rights reserved.
CRIS-Team Scopus Importer:2019-12-17

Entwicklung der marinen Biodiversität. - Kießling, Wolfgang (Humboldt-Spektrum, 2007)
Keywords: Biodiversität; Evolution; marine Organismen

Entwicklung einer katalytisch funktionalen porösen Keramik auf Basis hydraulisch aktiver Oxid-Keramiken - Enderle, Ralph; Göbbels, Matthias; Götz-Neunhoeffer, Friedlinde (European Journal of Mineralogy, 2003)
UnivIS-Import:2015-03-09:Pub.2003.nat.dgeo.IGM.LM.entwic

Entwicklung einer porösen Calciumphosphat-Keramik im Hinblick auf die Verwendung als Knochenersatzstoff - Göbbels, Matthias; Enderle, Ralph; Götz-Neunhoeffer, Friedlinde (European Journal of Mineralogy, 2005)
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LM.entwic

Environmental and evolutionary drivers of diversity patterns in the tea family (Theaceae s.s.) across China - Rao, Mide; Steinbauer, Manuel; Xiang, Xiaoguo; Mi, Xiangcheng; Zhang, Jingtun; Svenning, Jens-Christian (Ecology and Evolution, 2018)
Subtropical forest is recognized as an important global vegetation type with high levels of plant species richness. However, the mechanisms underlying its diversity are still poorly understood. Notably, species richness may be controlled by contemporary environment, but also by evolutionary dynamics (e.g., time-for-speciation or evolutionary rates), with the latter predicting relations between species richness and phylogenetic assemblage structure. Here, we assess the relative roles of these factors in shaping species diversity patterns at several taxonomic scales in a major subtropical plant group, the tea family (Theaceae s.s.) across China (145 species). To this end, we assessed the inter-relations between species richness, phylogenetic assemblage structure (net related index) and key environmental variables (minimum temperature of the coldest month, mean annual precipitation, soil pH), using generalized linear models and spatial linear models. We found that species richness is significantly related to environmental variables, especially decreasing with soil pH both across the whole family and within the tribe Theeae. Family-level species richness is unrelated to phylogenetic structure, providing no support for time-for-speciation or evolutionary rate effects. However, within the tribe Theeae, species richness was related to phylogenetic structure with an U-shaped relationship, a more complex relation than time-for-speciation or evolutionary rate hypothesis would predict. Overall, these results suggest that Theaceae species richness patterns within China are primarily driven by shallow-time environmentally-driven dynamics, albeit the nested patterns of its subgroups (notably Theeae) exhibit evolutionarily linked patterns. Our findings show that environmental and evolutionary processes interact in complex ways to shape species richness patterns within the subtropical forest biome.<br

Environmental and tectonic controls on preservation potential of distal fallout ashes in fluvio-lacustrine settings: the Carboniferous-Permian Saar-Nahe Basin, southwest Germany. - Königer, Stephan; Stollhofen, Harald (Volcaniclastic Sedimentation in Lacustrine Settings., 2001)
Thin but widespread fallout tuff layers form important stratigraphic markers in purely continental settings such as the Carboniferous–Permian Saar–Nahe Basin. They provide tools for the correlation of laterally variable lacustrine–deltaic sections and for the recognition of tectonically induced facies and thickness changes across faults. Not all the ash layers, however, were preserved as primary deposits; many were affected by reworking to varying degrees to form mixed pyroclastic–siliciclastic beds. The preservation of volcanic ash in the Saar–Nahe Basin was strongly influenced by the depositional environment. Specifically, volcanic ash falls deposited during the transgressive phases of sedimentary cycles had a high preservation potential. In addition, the preservation potential was strongly controlled by contemporaneous fault displacements. Ash beds deposited in footwall positions were highly affected by reworking and erosion and usually preserve only reduced thicknesses. In contrast, hanging-wall blocks provide an enhanced preservation potential for both primary and reworked ashes. Such sections record enhanced thicknesses, and the intercalation of siliciclastic interbeds cause complex lithological build-ups. The Late Variscan, intermontane Saar–Nahe Basin in south-west Germany developed as a north-east–south-west-trending 120 km × 40 km half-graben, which is subdivided by sets of orthogonal transfer faults. Its basin fill is characterized by purely continental, fluvio-lacustrine sediments revealing complex thickness and facies patterns as a result of contemporaneous tectonic faulting. During Stephanian (Kasimovian–Gzelian) and earliest Permian (Asselian) time, extrabasinally derived acidic volcanic ashes were deposited as distal pyroclastic fallout in lacustrine–deltaic dominated settings and subsequently altered to various clay mineral assemblages. Essentially three depositional settings with contrasting preservation potential can be distinguished: tuffs interbedded with offshore-lacustrine (black) shales have the highest preservation potential, and are usually preserved as primary deposits showing sharp and planar contacts, planar lamination (multiple) graded bedding, and laterally constant thickness; ashes reworked by turbidity currents form erosionally based, climbing-ripple and planar-bedded graded tuff horizons with load and flute casts at their bases; and tuffs interbedded with flood plain and crevasse splay sediments are often crossbedded and display both current and tool marks. Reworking is common and associated with abundant admixture of siliciclastic detritus or erosion of the entire tuff bed.
UnivIS-Import:2015-03-09:Pub.2001.nat.dgeo.IGM.LG.enviro

Environmental control on microbial turnover of leaf carbon in streams - Ecological function of phototrophic-heterotrophic interactions - Fabian, Jenny; Zlatanović, Sanja; Mutz, Michael; Grossart, Hans-Peter; van Geldern, Robert; Ulrich, Andreas; Gleixner, Gerd; Premke, Katrin (Frontiers in Microbiology, 2018)
Keywords: Terrestrial carbon; Algae; Bacteria; 13C stable isotopes; PLFA; Streambed structure; Light; Microbial interactions

Environmental crises at the Permian–Triassic mass extinction - Dal Corso, Jacopo; Song, Haijun; Callegaro, Sara; Chu, Daoliang; Sun, Yadong; Hilton, Jason; Grasby, Stephen E.; Joachimski, Michael; Wignall, Paul (Nature Reviews Earth and Environment, 2022)
The link between the Permian–Triassic mass extinction (252 million years ago) and the emplacement of the Siberian Traps Large Igneous Province (STLIP) was first proposed in the 1990s. However, the complex cascade of volcanically driven environmental and biological events that led to the largest known extinction remains challenging to reconstruct. In this Review, we critically evaluate the geological evidence and discuss the current hypotheses surrounding the kill mechanisms of the Permian–Triassic mass extinction. The initial extrusive and pyroclastic phase of STLIP volcanism was coeval with a widespread crisis of terrestrial biota and increased stress on marine animal species at high northern latitudes. The terrestrial ecological disturbance probably started 60–370 thousand years before that in the ocean, indicating different response times of terrestrial and marine ecosystems to the Siberian Traps eruptions, and was related to increased seasonality, ozone depletion and acid rain, the effects of which could have lasted more than 1 million years. The mainly intrusive STLIP phase that followed is linked with the final collapse of terrestrial ecosystems and the rapid (around 60 thousand years) extinction of 81–94% of marine species, potentially related to a combination of global warming, anoxia and ocean acidification. Nevertheless, the ultimate reasons for the exceptional severity of the Permian–Triassic mass extinction remain debated. Improved geochronology (especially of terrestrial records and STLIP products), tighter ecological constraints and higher-resolution Earth system modelling are needed to resolve the causal relations between volcanism, environmental perturbations and the patterns of ecosystem collapse.<br

Environmental determinants of marine benthic biodiversity dynamics through Triassic-Jurassic times - Kießling, Wolfgang; Aberhan, Martin (Paleobiology, 2007)
Ecology is thought to be of crucial importance in determining taxonomic turnover at geological time scales, yet general links between ecology and biodiversity dynamics are still poorly explored in deep time. Here we analyze the relationships between the environmental affinities of Triassic-Jurassic marine benthic genera and their biodiversity dynamics, using a large, taxonomically vetted data set of Triassic-Jurassic taxonomic occurrences. On the basis of binomial probabilities of proportional occurrence counts, we identify environmental affinities of genera for (1) carbonate versus siliciclastic substrates, (2) onshore versus offshore depositional environments, (3) reefs versus level-bottom communities, and (4) tropical versus non-tropical latitudinal zones. Genera with affinities for carbonates, onshore environments, and reefs have higher turnover rates than genera with affinities for siliciclastic, offshore, and level-bottom settings. Differences in faunal turnover are largely due to differences in origination rates. Whereas previous studies have highlighted the direct influence of physical and biological factors in exploring environmental controls on evolutionary rates, our analyses show that the patterns can largely be explained by the partitioning of higher taxa with different evolutionary tempos among environments. The relatively slowly evolving bivalves are concentrated in siliciclastic rocks and in level-bottom communities. Furthermore, separate analyses on bivalves did not produce significant differences in turnover rates between environmental settings. The relationship between biodiversity dynamics and environments in our data set is thus governed by the partitioning of higher taxa within environmental categories and not directly due to greater chances of origination in particular settings. As this partitioning probably has ecological reasons rather than being a simple sampling artifact, we propose an indirect environmental control on evolutionary rates. Affinities for latitudinal zones are not linked to systematically different turnover rates, possibly because of paleoclimatic fluctuations and latitudinal migrations of taxa. However, the strong extinction spike of tropical genera in the Rhaetian calls for an important paleoclimatic component in the end-Triassic mass extinction. © 2007 The Paleontological Society. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LP.enviro

Environmentally controlled succession in a late Pleistocene coral reef (Sinai, Egypt) - Mewis, H.; Kießling, Wolfgang (Coral Reefs, 2013)
The concept of ecological succession has been frequently applied in the study of ancient reefs. Whereas Paleozoic and Mesozoic reefs are commonly thought to reveal an autogenic primary-climax zonation, patterns in Neogene and Quaternary reefs are much more diverse. Here, we describe a well-preserved late Pleistocene coral reef from Dahab on Sinai Peninsula (Egypt), which shows a distinct zonation that resembles an ecological succession. In contrast to classical examples of ecological successions, species composition, paleoenvironmental conditions, and coral biodiversity of the Dahab reef indicate an allogenic, sea-level controlled community change, from marginal marine to reef slope and back reef. A review of the literature confirms that autogenic, short-term successions are virtually absent in Quaternary reefs. We predict that long generation times of corals make it unlikely that classical autogenic successions develop in reefs at all, unless environmental conditions are unusually stable. © 2012 Springer-Verlag Berlin Heidelberg.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LP.enviro_1
Keywords: Community ecology; Coral reef; Diversity; Ecological succession; Pleistocene; Red Sea

Environments and activity traces of Oldowan hominins across the FLK Peninsula during Zinjanthropus times (1.84 Ma), Olduvai Gorge, Tanzania - Blumenschine, Robert J.; Stanistreet, Ian G.; Njau, Jackson K.; Bamford, Marion K.; Masao, Fidelis T.; Albert, Rosa M.; Stollhofen, Harald; Andrews, Peter; Prassack, Kari A.; Mchenry, Lindsay J.; Fernandez-Jalvo, Yolanda; Camilli, Eileen L.; et al. (Journal of Human Evolution, 2012)
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.enviro

Equatorial decline of reef corals during the last Pleistocene interglacial - Kießling, Wolfgang; Simpson, Carl; Beck, Brian; Mewis, Heike; Pandolfi, John M. (Proceedings of the National Academy of Sciences of the United States of America, 2012)
The Last Interglacial (LIG; ca. 125,000 y ago) resulted from rapid global warming and reached global mean temperatures exceeding those of today. The LIG thus offers the opportunity to study how life may respond to future global warming. Using global occurrence databases and applying sampling- standardization, we compared reef coral diversity and distributions between the LIG and modern. Latitudinal diversity patterns are characterized by a tropical plateau today but were characterized by a pronounced equatorial trough during the LIG. This trough is governed by substantial range shifts away from the equator. Range shifts affected both leading and trailing edges of species range limits and were much more pronounced in the Northern Hemisphere than south of the equator. We argue that interglacial warming was responsible for the loss of equatorial diversity. Hemispheric differences in insolation during the LIG may explain the asymmetrical response. The equatorial retractions are surprisingly strong given that only small temperature changes have been reported in the LIG tropics. Our results suggest that the poleward range expansions of reef corals occurring with intensified global warming today may soon be followed by equatorial range retractions.
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LP.equato
Keywords: Biodiversity; Climate change; Paleobiology

Erdkabel-Systemdesign mit Unterstützung von Geodaten - Bertermann, David; Wagner, Jan; Jocic, Nikola; Schwarz, Hans; Stegner, Johannes (bbr - Leitungsbau, Brunnenbau, Geothermie, 2020)
Für das sich derzeit noch im Bundesfachplanungsverfahren befindliche ErdkabelGesamtvorhaben „SuedLink“ war es notwendig, im Rahmen der Studie „Thermische Bodenclusterung“ bereits zu einem frühen Projektzeitpunkt einen ersten Überblick über bodenphysikalische und klimatische Parameter mit Bedeutung für die Auslegung der Erdkabel zu gewinnen. Im Fokus stand u. a. die Bestimmung der Wärmeleitfähigkeit in Abhängigkeit der Tiefe und Lagerungsdichte sowie des Wasserhaushalts der jeweiligen Bodenart. Für die sich über die gesamte Länge des Erdkabel-Gesamtvorhabens erstreckenden Untersuchungsräume wurden digitale Flächen- und Bohrdaten der Landesämter sowie bundesweite Klimadaten genutzt. Alle Daten wurden in eine Geodatenbank implementiert und mithilfe eines Geoinformationssystems (GIS) prozessiert, interpoliert und visualisiert. <br
Keywords: Erdkabel; SuedLink; Boden; GIS

Erfolgreich Forschen durch Kooperation - Verknüpfung hochschuleigener Informationsinfrastrukturen zu einem zentralen Service für Forschende - Putnings, Markus; Teichert, Sebastian (106. Deutscher Bibliothekartag, 2017)
Mehrere Universitäten in Deutschland bieten über eine Abteilung Forschung“ einzelne Serviceleistungen, bspw. für Patentangelegenheiten, an. An der Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) entstand darüber hinausgehend durch die Kooperation zwischen den vier Referaten der Forschungsabteilung, den Forschungsreferentinnen und -referenten der Fakultäten, der Universitätsbibliothek (UB) sowie weiteren Einrichtungen (Forschungsmarketing, Dual Career Service etc.) ein außergewöhnlich umfassender Service für Forschende. Der Vortrag zeigt als Best Practice-Beispiel, wie diese Dienste ineinandergreifen und wie Hochschulbibliotheken ihre wertvollen Fähigkeiten in den Bereichen Informationsbeschaffung und -vermittlung einbringen können, um den gesamten Forschungsprozess kooperativ mit anderen zu stützen. Dazu präsentieren die Forschungsabteilung und die UB die Verflechtung ihrer Aufgabengebiete. Ein Beispiel betrifft dabei die Durchführung von Drittmittelprojekten. Hierbei fällt die administrative Bearbeitung und Beratung im Umfeld von Kooperations-, Forschungs- und Entwicklungsverträgen sowie des Arbeitnehmererfinderrechts in die Verantwortung der Forschungsabteilung. Die UB betreut parallel die Beratung zu den Open Access- und Open Data-Policies der Drittmittelgeber und den hierbei zu beachtenden Klauseln, empfehlenswerten Geldsummen, die mitbeantragt werden sollten, sowie Fragen zu freien Lizenzen. Als weitere Beispiele werden u. a. die Erfinderberatung und die Patentrechercheschulungen der UB, die gemeinsame Zuarbeit zur Evaluierung der Fakultäten oder die Fortbildungsangebote der UB im Rahmen der Graduiertenschule vorgestellt. Damit dient dieser globale Service für Forschende (https:www.fau.deforschungservice-fuer-forschende) sowohl dem wissenschaftlichen Nachwuchs als auch den etablierten Forschenden an der FAU, egal ob grundlagen- oder anwendungsorientiert, sowie der Universitätsleitung und der Forschungsverwaltung an den Fakultäten.
Keywords: Forschungsberatung; Forschungskooperation; Informationsinfrastruktur; Wissenschaftliche Einrichtung

Erratum: Lithospheric control on geochemical composition along the Louisville Seamount Chain (Geochemistry, Geophysics, Geosystems (2012) 13 (Q0AM03) DOI: 10.1029/2011GC004012) - Beier, Christoph; Vanderkluysen, Loÿc; Regelous, Marcel; Mahoney, John J.; Garbe-Schönberg, Dieter (Geochemistry Geophysics Geosystems, 2012)
Keywords: lithosphere thickness; Louisville Seamount Chain; melting dynamics; plume evolution; spreading center

Erratum: Progressive changes in crystallographic textures of biominerals generate functionally graded ceramics (Mater. Adv. (2022) DOI: 10.1039/d1ma01031j) - Wallis, David; Harris, Joseph; Böhm, Corinna; Wang, Di; Zavattieri, Pablo; Feldner, Patrick; Merle, Benoit; Pipich, Vitaliy; Hurle, Katrin; Leupold, Simon; Hansen, Lars N.; Marin, Frederic; et al. (Materials Advances, 2022)
The authors regret that the affiliation details in the original article for the authors Simon Leupold, Lars N. Hansen, and Frederic Marin were incorrect. The full and corrected list of affiliations are given in this document. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.
CRIS-Team Scopus Importer:2022-04-15

Erratum zu: Stabile Isotope als Tracer zur Bestimmung der Abstandsgeschwindigkeit in Trinkwassergewinnungsbrunnen aus Uferfiltrat (Grundwasser, (2015), 10.1007/s00767-015-0296-6) - van Geldern, Robert; Kolb, Angela; Baier, Alfons; Barth, Johannes (Grundwasser, 2016)

Erste Ergebnisse von Suszeptibilitätsmessungen an Vulkaniklastika der Forschungsbohrung Messel - de Wall, Helga; et al. (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 2005)
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.c3tekt.erstee

Estimating the thermal properties of soils and soft rocks for ground source heat pumps installation in Constanta county, Romania - Vijdea, Anca-Marina; Weindl, Christopher; Cosac, Ana; Asimopolos, Natalia-Silvia; Bertermann, David (Journal of Thermal Analysis and Calorimetry, 2014)
Keywords: Bulk density; Geographical information system; Grain size; Pore size distribution; Thermal conductivity; Geologie; erneuerbare Energiequelle; Bodenkunde

Ethics, law, and politics in palaeontological research: The case of Myanmar amber - Dunne, Emma; Raja, Nussaïbah Begum; Stewens, Paul P.; Zin-Maung-Maung-Thein,; Zaw, Khin (Communications Biology, 2022)
Fossil material in amber from Myanmar can provide important insights into mid-Cretaceous forest ecosystems. However, Myanmar amber has been receiving increased international attention due to reported links between amber mining and the ongoing humanitarian crisis in northern Myanmar, as well as the legal issues associated with its exportation. Here, we conduct a bibliometric analysis of Myanmar amber publications (1990–2021) and demonstrate how research interest in Myanmar amber is explicitly linked to major political, legal, and economic changes. An analysis of the authorship networks for publications on amber inclusions reveals how current research practices have excluded Myanmar researchers from the field. In addition, the international trade of Myanmar amber with fossil inclusions falls into a legal ‘grey-zone’ which continues to be exploited. This case study vividly demonstrates that systemic changes, alongside an increased awareness of inequitable research practices amongst the broader scientific and allied communities, are urgently needed to curb illegal practices in palaeontology.
CRIS-Team Scopus Importer:2022-10-14

EU-project „Cheap-GSHPs“ - Reduced installation costs for geothermal heating by using new developed heat baskets and drilling techniques - Bertermann, David; Di Sipio, Eloisa; Bernardi, Adriana; de Carli, Michele; Bernini, Michele; Pockelé, Luc; Psyk, Mario; Vercruysse, Jacques; Müller, Johannes (GeoTirol2016 - Annual Meeting of DGGV and PANGEO Austria, 2016)

EU PROJECT “CHEAP GSHPs”: THE GEOEXCHANGE FIELDLAB - Galgaro, Antonio; Cultrera, Matteo; Dalla Santa, Giorgia; Bertermann, David; Müller, Johannes; de Carli, Michele; Emmi, Giuseppe; Zarrella, Angelo; Bernardi, Adriana; Di Tuccio, Maria; Vivarelli, Arianna; Pockelé, Luc; et al. (Geophysical Research Abstracts Vol. 19, 2017)

EU project "cheap-GSHPs": The geoexchange field laboratory - Dalla Santa, Giorgia; Bernini, Michele; Müller, Johannes; Zarrella, Angelo; Cultrera, Matteo; Di Tuccio, Maria; Bernardi, Adriana; Bertermann, David; Pockelé, Luc; Galgaro, Antonio; Mezzasalma, Giulia; de Carli, Michele; et al. (Energy Procedia, 2017)
Keywords: Cheap-GSHPs; coaxial probe; GSHE; heat basket; thermal conductivity; Geologie; erneuerbare Energiequelle

European Project “Cheap-GSHPs” – Cheap and efficient applications of reliable Ground Source Heat Exchangers and Pump - Bertermann, David; Bernardi, Adriana; Galgaro, Antonio; de Carli, Michele; Pockelé, Luc; Poletto, Davide; Castelruiz Aguirre, Amaia; Mendrinos, Dimitrios; Pasquali, Riccardo; Urchueguía, Javier; Gavriliuc, Robert; Müller, Johannes (Der Geothermie Kongress 2017, 2017)
Nowadays the energy price fluctuations and the economic crisis are jeopardizing the development and diffusion of renewable technologies and sources. With the aim of both reduce the overall costs of shallow geothermal systems and improve their installation safety, an European project has took place recently, under the Horizon 2020 EU Framework Programme for Research and Innovation. The acronym of this project is Cheap-GSHPs, meaning "Cheap and efficient application of reliable Ground Source Heat exchangers and Pumps"; the Cheap-GSHPs project involves 17 partners among 9 European countries such Belgium, France, Germany, Greece, Ireland, Italy, Romania, Spain, Switzerland. In order to achieve the planned targets, an holistic approach is adopted, where all involved elements that take part of shallow geothermal activities are here integrated. The general objectives within this project is the reduction of total costs of ownerships, the increase of the deployment of this technique versus the current estimates, a contribution to the environment via CO2 emission reduction and finally demonstrations that this technology is feasible even in civil and historical buildings (6 real and 10 virtual cases). To this day the first results are a pan-European geological data set with drillability information, a structural cost-analyse of main types of ground source heat exchangers (GSHE), a new designed heat basket type GSHE, improvements in coaxial GSHE installations, a conceptual heat pump study, constructing of a user-friendly decision support system (DSS) and a pan-European legislative and regulatory analysi

European Project “Cheap-GSHPs” – Installation and monitoring of new designed helicoil ground source heat exchanger on the German test site - Bertermann, David; Bernardi, Adriana; Pockelé, Luc; Galgaro, Antonio; Cultrera, Matteo; de Carli, Michele; Müller, Johannes (5th International Conference Novel Methods for Subsurface Characterization and Monitoring: From Theory to Practice, 2017)

European project “Cheap-GSHPs”: installation and monitoring of newly designed helicoidal ground source heat exchanger on the German test site - Bertermann, David; Bernardi, Adriana; Pockelé, Luc; Galgaro, Antonio; Cultrera, Matteo; de Carli, Michele; Müller, Johannes (Environmental Earth Sciences, 2018)
Nowadays, the energy price fluctuations and the economic crisis are jeopardizing the development and diffusion of renewable technologies and sources. With the aim of both reducing the overall costs of shallow geothermal systems and improving their installation safety, an European project has took place recently, under the Horizon 2020 EU Framework Programme for Research and Innovation. The acronym of the mentioned project is Cheap-GSHPs, meaning “cheap and efficient application of reliable ground source heat exchangers and pumps”; the Cheap-GSHPs project involves 17 partners among 9 European countries such as Belgium, France, Germany, Greece, Ireland, Italy, Romania, Spain and Switzerland. In order to achieve the planned targets, a holistic approach is adopted, where all involved elements that take part of shallow geothermal activities are here integrated. In order to reduce the specific costs of geothermal installations, some newly designed geometries of heat basket-type ground source heat exchanger (GSHE) are modified drastically to receive a better performance of the geothermal installation. Within the sector of very shallow geothermal systems, these new developments are also tested on six representative demonstration sites around Europe. At the German test site in Northern Bavaria, four heat basket-type GSHEs are installed and equipped with certain monitoring systems (moisture, two different temperature sensors) and various backfilling materials of different grain size classes. The different installations will be tested for 12 months to evaluate the best combination of the newly designed heat basket-type GSHE and corresponding backfilling material mixture.

European Project GEO4CIVHIC - Most Easy, Efficient and Low Cost Geothermal Systems for Retrofitting Civil and Historical Buildings - Bertermann, David; Bernardi, Adriana; Galgaro, Antonio; de Carli, Michele; Urchueguía, Javier; Mezzasalma, Giulia; Pasquali, Riccardo; Poletto, Fabio; Noyé, Sarah; Ulrich, Dirk; Poletto, Davide; Gavriliuc, Robert; et al. (Der Geothermie Kongress 2019, 2019)
The building retrofit market today barely reaches 1 % of the actual building stock. In addition, the interventions are of shallow nature in the majority of the buildings. The energy transition initiative of the European Commission is focusing on increasing the retrofitting of the building stock from the current 1 % level to 3 % and to shift the nature of the interventions towards deep retrofits. The GEO4CIVHIC project (https://geo4civhic.eu/) is one further step of many in research and innovation to increase shallow geothermal applications in buildings. The revision and implementation into legislation of the EPBD, the Energy Efficiency Directive and the Renewable Energy Directive by the EC, coupled with financial support mechanisms (e.g. tax reductions for deep retrofits, premiums for renewable energy systems) will contribute as well. The GEO4CIVHIC activities are organized in three groups named blocks. The first group (technical block) deals with the technical innovations and solutions to be realized and demonstrated starting from the state of art and the specific needs of building retrofits. The high drilling cost needs to be tackled. Drilling with highly efficient but heavy and large drilling machines is difficult and often impossible in the built urban environment. The use of smaller, less powerful machines leads to even higher drilling costs. Hence increasing the thermal efficiency of the Ground Source Heat Exchangers (GSHEs) is another way to reduce the total length (and therefore the costs) of GSHE system to be installed. Innovations are introduced in each component: Drilling Machines and Methodology, GSHE design and materials, compact and hybrid heat pumps (HPs) for high and low temperature terminals. Development of the heat pumps should also contribute to the decrease of the total investment or the increase of the overall efficiency. Heat pumps with good performance at higher temperatures avoid the need to replace all or parts of the heating terminals. A Decision Support System (DSS) will deliver the most suitable technical solution for each facility and a Building Management System (BMS) will allow the use of other renewable energy sources and optimization of the controls. The second group (economic & market block) addresses the introduction of these technologies to the market. The stakeholders united in the broad consortium, including architects, drilling machine builders, drillers, HP suppliers, engineers and academics specialized in shallow geothermal applications, HVAC systems and HPs will provide their expertise. The stable nature of geothermal as a renewable energy source, the ability of heating/cooling with only one system and the higher residual value of buildings retrofitted with this technology are additional key factors for investors who are focusing on the long-term value of retrofits. The third group (environmental & standardization block) deals with the legislative, environmental and European standard aspects, dealing with the project innovations for which recommendations and modifications will be developed through experienced consortium partners being members of standards organizations and geothermal associations. The main goal of the GEO4CIVHIC project will be to tackle all of the above-mentioned areas by developing and demonstrating more easy to install and more efficient GSHEs, using drilling machine innovations tailored for the built and also historical environment and developing or adapting heat pumps and other hybrid solutions for retrofits through a holistic engineering, construction and controls approach.
Keywords: Ground Source Heat Pump; Drilling; Borehole Heat Exchanger; Retrofit; Historic Buildings

Evaluation of high-frequency paleoenvironmental variation using an optimized cyclostratigraphic framework: Example for C-S-Fe analysis of Devonian-Mississippian black shales (Central Appalachian Basin, U.S.A.) - Liu, Jiang Si; Algeo, Thomas J.; Jaminski, Jacek; Kuhn, Thomas; Joachimski, Michael (Chemical Geology, 2019)
Stratigraphic successions are rarely sampled at sufficiently dense spacing to permit evaluation of paleoenvironmental variation at the shortest fundamental frequency operative in the depositional system of interest, often because that frequency remains undetermined. Here, we provide an example of a sampling strategy optimized for recovery of high-frequency paleoenvironmental signals, based on (1) full-core analysis using a continuous survey tool such as X-radiography, followed by (2) fine sampling of selected small-scale cycles that record significant short-term paleoenvironmental variation. We show that this strategy results in recovery of high-frequency paleoenvironmental signals that are completely missed by low-density sampling protocols, permitting key insights into depositional and early diagenetic processes that may otherwise by overlooked. The present case study is based on C-S-Fe systematics of the Cleveland and Sunbury shales, which belong to the Upper Devonian-lowermost Carboniferous black shale succession of the Central Appalachian Basin in eastern North America. In these units, the fundamental scale of paleoenvironmental variation is recorded by pervasive decimeter-scale ( 5- to 20-cm-thick) compositional cycles that are readily visible in outcrop, in which high-organic layers weather out as resistant ledges. We identified these cycles in drillcores using X-radiography, which proved to be an effective proxy for compositional variation owing to control of bulk density primarily by total organic carbon (TOC) content. We then sampled selected dm-scale cycles (n = 21) at a centimeter spacing, generating short, high-resolution, multiproxy chemostratigraphic records including TOC, sulfur and Fe concentrations, Fepy/FeHR (a redox proxy), δ34Spyrite, and organic maceral content. This analysis yielded the novel insight that all proxies related to authigenic iron sulfides (e.g., Stotal and Spyrite, Fetotal and Fepyrite, Fepy/FeHR, and δ34Spyrite) covary negatively with TOC within the dm-scale cycles. We interpret the unusual pattern of negative TOC-pyrite covariation in the Cleveland and Sunbury shales to have resulted from differential distributions of labile organic matter (OM), which drove H2S production via microbial sulfate reduction (MSR), and reactive Fe, which controlled pyrite formation. Labile OM was concentrated in high-TOC layers whereas reactive Fe was concentrated in low-TOC layers (possibly as Fe-oxyhydroxide coatings on silt grains), as a consequence of which part of the H2S generated in the high-TOC layers diffused upward into the low-TOC layers before becoming fixed as pyrite. This process is evidenced by several contrasts between high-TOC and low-TOC layers: (1) higher Spyrite concentrations and Fepy/FeHR values in the latter, (2) concentration of pyrite in the lower part of low-TOC layers, immediately above high-TOC layers, and (3) higher δ34Spyrite values in the latter, reflecting late diagenetic formation of the H2S that diffused upward into the low-TOC layers. To our knowledge, this process has not been documented previously in ancient marine shales, probably owing to insufficiently high-resolution analysis in earlier studies.
CRIS-Team Scopus Importer:2019-08-23
Keywords: Anoxia; Cleveland Shale; Productivity; Pyrite; Redox; Sunbury Shale

Evidence for a complex nannoconid decline in the Vocontian basin (South East France). - Barbarin, Nicolas; Bonin, Aurelie; Mattioli, Emanuela; Puceat, Emmanuelle; Cappetta, Henri; Greselle, Benjamin; Pittet, Bernard; Vennin, Emmanuelle; Joachimski, Michael (Marine Micropaleontology, 2012)
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.marine

Evidence for compositionally distinct upper mantle plumelets since the early history of the Tristan-Gough hotspot - Homrighausen, Stephan; Hoernle, Kaj; Hauff, Folkmar; Hoyer, Patrick; Haase, Karsten; Geissler, Wolfram H.; Geldmacher, Jörg (Nature Communications, 2023)
Recent studies indicate that mantle plumes, which transfer material and heat from the earth’s interior to its surface, represent multifaceted upwellings. The Tristan-Gough hotspot track (South Atlantic), which formed above a mantle plume, documents spatial geochemical zonation in two distinct sub-tracks since 70 Ma. The origin and the sudden appearance of two distinct geochemical flavors is enigmatic, but could provide insights into the structural evolution of mantle plumes. Sr–Nd–Pb–Hf isotope data from the Late Cretaceous Rio Grande Rise and adjacent Jean Charcot Seamount Chain (South American Plate), which represent the counterpart of the older Tristan-Gough volcanic track (African Plate), extends the bilateral-zonation to 100 Ma. Our results support recent numerical models, demonstrating that mantle plumes can split into distinct upper mantle conduits, and provide evidence that these plumelets formed at the plume head-to-plume tail transition. We attribute the plume zonation to sampling the geochemically-graded margin of the African Large Low-Shear-Velocity Province.
CRIS-Team Scopus Importer:2023-07-21

Evidence for melting of subducting carbonate-rich sediments in the western Aegean Arc - Wölki, Dominic; Haase, Karsten; Schönhofen, Milena; Beier, Christoph; Regelous, Marcel; Krumm, Stefan; Günther, Thomas (Chemical Geology, 2018)

Evidence for Palaeozoic orthoconic cephalopods with bimineralic shells - de Baets, Kenneth; Munnecke, Axel (Palaeontology, 2018)
Based on the aragonite composition of extant and exceptionally preserved fossil cephalopods going back to the early Palaeozoic, it is commonly assumed that all externally shelled cephalopods had an aragonitic shell wall. We demonstrate herein that at least two taxa of Siluro-Devonian orthoconic nautiloids (Dawsonoceras, Spyroceras) had an original bimineralic shell, which developed convergently with gastropods and bivalve

Evidence for preindustrial variations in the marine surface water carbonate system from coralline sponges - Joachimski, Michael; et al. (Geochemistry Geophysics Geosystems, 2002)
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.LG.eviden

Evidence for the sinistral Porcupine shear zone in North Yukon (Canadian Arctic) and geotectonic implications - von Gosen, Werner; Piepjohn, K.; Mcclelland, W. C.; Colpron, M. (Special Paper of the Geological Society of America, 2019)
Structural analysis of Neoproterozoic to lower Paleozoic rocks near Old Crow, in North Yukon, show that they were affected by widespread, but distributed sinistral shear zone deformation. This tectonic event occurred under brittle-ductile conditions, in the early Paleozoic, prior to intrusion of Late Devonian granitoids of the Old Crow plutonic suite (368-375 Ma). Although outcrops are scattered, the shear zone deformation can be inferred to extend over a broad similar to W-E corridor, similar to 10-20 km-wide and similar to 145 km long, from eastern Alaska into northern Yukon. The sinistral Porcupine shear zone is interpreted to represent a major, early Paleozoic crustal structure along which elements of NE Laurentian and Caledonian affinities in the Arctic Alaska terrane were transferred across the Arctic region during the Paleozoic. Our observations do not support major Paleogene dextral strike-slip deformation along the Porcupine River near Old Crow.
CRIS-Team WoS Importer:2019-11-15

Evidence of parallel evolution in the dental elements of Sweetognathus conodonts - Petryshen, W.; Henderson, C. M.; de Baets, Kenneth; Jarochowska, Emilia (Proceedings of the Royal Society of London, Series B: Biological Sciences, 2020)
The repeated emergence of similar morphologies in the dental elements of Permian Sweetognathus conodonts has been a hypothesized example of parallel evolution. To test if morphological parallelisms occur between isolated Sweetognathus lineages, this study uses two-dimensional-based geometric morphometrics combined with a revised and expanded phylogeny of Permian Sweetognathus conodonts to quantify dental element trait distributions and compare the phenotypic trajectories between lineages. A hierarchical clustering method was used to identify recurrent species pairs based on principal component scores describing their morphological variation, with the further incorporation of widely used ecological metrics such as limiting similarity and morphological overlap. Our research implies that a major contributor to conodont diversity in Palaeozoic marine trophic networks is the emergence of recurrent parallel morphologies via disruptive and directional selection. This study illustrates the mechanisms through which conodonts achieved their status as hyper-diverse predators and scavengers, contributing substantially to the complexity of Palaeozoic marine communities.
CRIS-Team Scopus Importer:2020-11-27
Keywords: conodont trophic networks; parallel evolution; Sweetognathus

Evolution and genesis of calc-alkaline magmas at the Paphsanias Volcanic Field, Aegean Arc - Günther, Thomas; Wölki, Dominic; Storch, Bettina; Beier, Christoph; Haase, Karsten (GeoBonn2018, 2018)
The Aegean arc is one of the arcs with the highest rate of sediment subduction and 8 km of sediment are found in the Hellenic Trench. In 1984, the submarine Paphsanias Volcanic Field was discovered west of the islands of Methana and Aegina, the two major westernmost volcanic centers of the Aegean Arc. The Paphsanias Volcanic Field consists of six volcanic structures ranging from massive lava flows to relatively complex volcanic structures with heights of 300 m. These volcanic structures represent an early stage of submarine volcanism of the Aegean arc volcanoes. Four of the Paphsanias volcanic structures were sampled during the Pos512 cruise in 2017 and here we discuss the preliminary petrological and geochemical data of 100 samples with basaltic to andesitic compositions. The basis of two of the Paphsanias volcanic structures consist of basaltic lava flows with 10 to 7 wt.% MgO and 150 to 80 ppm Ni, whereas the shallower flows and lava domes have andesitic compositions. Here, we suggest that most andesites are generated by either fractional crystallization or magma mixing between mafic and silicic melts during replenishment of shallow crustal magma reservoirs. The Paphsanias basalts are more mafic than lavas from neighboring Methana but also than known mafic lavas form other Aegean volcanoes. Iron and Ti contents of the Paphsanias and Methana lavas follow the same calc-alkaline trend. However, one of the submarine volcanoes shows V contents that overlap with the tholeiitic trend of lavas from Santorini which may reflect a change in state of redox state of the Paphsanias Volcanic Field. Compared to Santorini, ratios of Ba/Nb, Nb/Zr and Zr/Y are more enriched and probably indicate different degrees of partial melting, enrichment of the mantle source, and/or variable crust addition.<br

Evolution and tectonic setting of the Malani – Nagarparkar Igneous Suite: A Neoproterozoic Silicic-dominated Large Igneous Province in NW India-SE Pakistan - de Wall, Helga; Pandit, Manoj K.; Donhauser, Ines; Schöbel, Stefan; Wang, Wei; Sharma, Kamal K. (Journal of Asian Earth Sciences, 2018)
Keywords: Crustal extension; Dyke swarm; Malani Igneous Suite; Geochemistry; Granite geochronology

Evolutionary diversification of reef corals: a comparison of the molecular and fossil records - Simpson, Carl; Kießling, Wolfgang; Mewis, Heike; Baron-Szabo, Rosemarie; Müller, Johannes (Evolution, 2011)
Understanding historical patterns of diversity dynamics is of paramount importance for many evolutionary questions. The fossil record has long been the only source of information on patterns of diversification, but the molecular record, derived from time-calibrated phylogenies, is becoming an important additional resource. Both fossil and molecular approaches have shortcomings and biases. These have been well studied for fossil data but much less so for molecular data and empirical comparisons between approaches are lacking. Here, we compare the patterns of diversification derived from fossil and molecular data in scleractinian reef coral species. We also assess the robustness of molecular diversification rates to poor taxon sampling. We find that the temporal pattern of molecular diversification rates is robust to incomplete sampling when rates are calculated per interval. The major obstacle of molecular methods is that rate estimates are distorted because diversification rates can never be negative, whereas the fossil record suffers from incomplete preservation and inconsistent taxonomy. Nevertheless, the molecular pattern of diversification is comparable to the pattern we observe in the fossil record, with the timing of major diversification pulses coinciding in each dataset. For example, both agree that the end-Triassic coral extinction was a catastrophic bottleneck in scleractinian evolution. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution..
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LP.evolut
Keywords: Diversification; Extinction; Fossils; Molecular phylogenies; Reef corals; Speciation

Evolutionary History of Cephalopod Pathologies Linked with Parasitism - de Baets, Kenneth; Hoffmann, René; Mironenko, Aleksandr (The Evolution and Fossil Record of Parasitism: Coevolution and Paleoparasitological Techniques, 2021)
Extant cephalopod soft tissues are commonly infested by various lineages of parasites making it plausible that extinct cephalopods also had a variety of parasites. Direct evidence of such a relationship is rare, due to the low preservation potential of soft tissues of fossil cephalopods and parasites alike, and the relatively scarce infestation of mineralized tissue by parasites. Evidence for infestations in the fossil record is, therefore, overall rare and limited to shell pathologies. Comparative studies on these structures in extant cephalopods are also not very numerous. Based on similar bauplans and biomineralization pathways, parasite-induced pathologies in bivalves and gastropods can inform about their causes. The position of these features might reveal their parasitic nature. The restriction of these structures to certain cephalopod lineages might indicate the influence of phylogeny, anatomy and potential role of ecology (feeding, mode of life) on infestation risks. However, preservation and research biases might also contribute to differences between externally and internally shelled cephalopods. Other long-term associations with detriment to cephalopods such as epizoa and bioerosion as well as other malformations, which can be confused with parasitic causes, are briefly discussed.
Keywords: Paleopathology; Blister-pearls; Volume-changing pathologies; Asymmetry; Apertural shell growth; Gigantism; Parasitosis

Evolutionary implications of an exceptionally preserved Carboniferous microboring assemblage in the Buckhorn Asphalt Lagerstätte (Oklahoma, USA) - Wisshak, Max; Seuß, Barbara; Nützel, Alexander (Current Developments in Bioerosion, 2008)
In the Buckhorn Asphalt deposit, exceptional preservation of mollusc shells with original aragonitic mineralogy, owing to an early impregnation with migrating hydrocarbons, provides a 'preservational window' for studying a Late Palaeozoic microboring assemblage. The evaluation of thin-sections, bioclast surface features, and SEM analysis of epoxy resin casts reveals a total of 18 known ichnospecies and the new ichnotaxon Aurimorpha varia - reflecting the most diverse Palaeozoic microboring assemblage known to date. The ichno-inventory is dominated by the cyanobacterial traces Eurygonum nodosum, Scolecia filosa, and Fascichnus dactylus, complemented by the common Fascichnus frutex, Planobola macrogota and Cavernula coccidia, and the chlorophyte traces Cavernula pediculata and Rhopalia catenata. Presumable borings of heterotrophs are rare albeit diverse constituents of the microboring assemblage. The ichnocoenosis composition indicates a palaeoenvironment in the shallow-euphotic zone and is in many respects 'modern'. The fact that 17 out of the 19 recorded ichnospecies are also known to neoichnology in closely similar ichnocoenoses of today's shallow-euphotic seas underlines the pronounced longevity of microendolithic taxa and promotes their value as deep-time palaeoenvironmental indicator. Two thirds of the recorded ichnotaxa were reported for the first time from Carboniferous strata, thereby extending the known stratigraphic range of Cavernula pediculata, Cavernula coccidia, Rhopalia catenata, Rhopalia spinosa, Scolecia serrata, Polyactina fastigata, Saccomorpha terminalis, and Aurimorpha varia igen. n., isp. n. back into the Palaeozoic. This shows that at least 21 ichnospecies, including a high number of modern ichnotaxa, were established as early as the late Palaeozoic and reflects an increasing abundance and potential competition by chlorophyte algae and heterotroph microborers breaking the former strong dominance of endolithic cyanobacteria in microborer communities. The curve of Phanerozoic ichnospecies diversity suggests that the evolution of microbioerosion agents is to a certain degree parallel to that of the macroborers with main radiations in the Ordovician and Devonian. However, according to the current state of knowledge, the end-Permian mass extinction event seemingly had little or no impact on the diversity and evolution of microborers. Thus, diversity patterns of micorborings differ from those of marine invertebrates, most of which have a minimum in standing diversity at the Permian/Triassic boundary and a general turn-over from typical Palaeozoic to modern evolutionary faunas. © 2008 Springer-Verlag Berlin Heidelberg.
UnivIS-Import:2015-04-20:Pub.2008.nat.dgeo.IGM.LP.evolut
Keywords: Aurimorpha varia; Bioerosion; Buckhorn Asphalt; Evolution; Lagerstätte; Microborings; Pennsylvanian

Evolutionary Patterns of Ammonoids: Phenotypic Trends, Convergence, and Parallel Evolution - Monnet, Claude; Klug, Christian; de Baets, Kenneth (Ammonoid Paleobiology: From macroevolution to paleogeography, 2015)

Evolution of a calcite marble shear zone complex on Thassos Island, Greece: Microstructural and textural fabrics and their kinematic significance - Bestmann, Michel; et al. (Journal of Structural Geology, 2000)

Evolution of a shear zone in calcite marble on Thassos Island, Northern Greece: results from microfabrics and stable isotopes. - Bestmann, Michel (Erlanger Geologische Abhandlungen, 2000)
The metamorphic succession of Thassos Island, Northern Greece, is dominated by massive marble complexes in alternation with paragneisses, orthogneisses and amphibolites that show fabric development under retrograde metamorphic conditions. During extensional tectonics, linked to the exhumation process of the metamorphic core complex strain localization occurred in response to decreasing pressure-temperature conditions. In pure calcite marble complexes, this stage of deformation is recorded by several shear zones of up to 3 m thickness which are oriented parallel to the foliation plane in the host rocks. The mylonitic shear plane of the shear zone interior is also oriented parallel to the shear zone boundary (SZB) which is considered to be the basic reference plane. The history of a monophase shear zone complex in calcite marble is reconstructed by detailed studies of the crystallographic preferred orientation (CPO, texture) and microstructural patterns. Combined cathodoluminescence (CL), stable isotope (d18O, d13C), and geochemical analyses are used to evaluate possible metamorphic fluids and/or mass transfer during the deformation history of the shear zone complex. Outside the investigated shear zone, the calcite fabric of the protolith marble is equigranular and coarse-grained (grain size 1-3 mm) with a high density of twin lamellae. Twins are oriented both clockwise and anticlockwise to the long axes of the grains, which are oriented more or less parallel to the macroscopic foliation. The texture is characterized by a single c-axis maximum oriented perpendicular to the reference plane (SZB). Both a-axis pole figures (+a and –a) show very similar girdle distributions within the reference plane. The textures of the protolith are comparable with patterns found in experimentally deformed calcite marble and simulated textures under pure shear conditions within the twinning regime. The overall microfabric (texture & microstructure) of the protolith exhibits orthorhombic symmetry indicating a dominant coaxial deformation (pure shear strain path). The investigated foreland-directed shallow-dipping shear zone cuts through the ‘already‘ deformed coarse-grained calcite marble complex. The boundaries of the shear zone are marked by sharp transitions in the grain size, with a narrow zone of protomylonitic fabric. Orientation Imaging Microscopy (OIM) demonstrates that lattice rotation represents the starting point in the process of dynamic recrystallization accompanied by grain size reduction. Preferred orientation of grain shape and one dominant twin orientation in the porphyroclasts of the protomylonite are oblique to the SZB and reveal a monoclinic symmetry, due to a non-coaxial strain component (simple shear strain path). Related to the protolith the texture of the protomylonite is slightly rotated with the sense of shear, but still preserves the orthorhombic internal texture symmetry of the protolith. The protomylonite shows inhomogeneous microstructural fabrics that are related to the degree of dynamic recrystallization, which is strain and time dependent. In contrast, the fine-grained ultramylonite in the interior of the shear zone is completely dynamically recrystallized with a homogeneous microstructure, which is more likely to represent a ‘steady state’ of flow. Dynamic recrystallization is accompanied by a strong grain size reduction (grain size 10-30 µm). The interior of the dynamically recrystallized grains is generally free from twins. Therefore, twinning does not play any role during deformation of ultramylonite, as in the case of protolith and protomylonite. Mylonitization under dominant non-coaxial deformation conditions in the shear zone is indicated by a grain shape preferred orientation in oblique angle to the SZB. Asymmetric (‘s-shaped’) quartz grains with wedge shaped appendages are incorporated in the calcite matrix and correspond to a top-to-the SW shear direction in the ultramylonite. The texture of the ultramylonite shows a single c-axis maximum normal to the SZB. Whereas both of the separated a-axis pole figures of the protolith and protomylonite show similar girdle distributions, the ultramylonite exhibits a different distribution of distinct maxima in the respective a-axis pole figures. Thus the texture of the ultramylonite has clearly no orthorhombic sample symmetry but contains the symmetry elements of a monoclinic sample system as also indicated by the microstructures. The ‘steady state’ microstructure and the CPO favour slip systems with a stable end orientation of ‘easy slip’, with slip planes within the shear plane, and slip direction parallel to the shear direction. Here, the ‘easy slip’ system would be (0001)<10-10> (basal-m), which has never been reported for calcite. The texture of the ultramylonite with the different a-axis maxima at a specific angle relative to the shear direction can be explained by duplex slip on different but energetically equivalent -directions on the basal plane (0001). This study demonstrates that pure shear, as well as simple shear strain paths, can produce similar c-axis fabrics by different dominant deformation mechanisms. The separated a-axis pole figures show different density distributions indicating orthorhombic texture symmetry for the protolith and trigonal-monoclinic symmetry for the ultramylonite. The differently strained calcite marbles (protolith, protomylonite, and ultramylonite) show different rheological behaviour during deformation, and are respectively accompanied by characteristic strain configurations (degree of coaxial flow to non-coaxial flow). It seems probable that the entire calcite marble complex has undergone a component of early coaxial deformation during the uplift of the metamorphic core complex. Finally, the shallow dipping shear zone cuts through the 'already' deformed coarse-grained calcite marble complex related to foreland-directed extensional tectonics under retrograde conditions. High strain is accommodated together with non-coaxial flow. There are no significant isotopic differences in d18O and d13C within and outside the calcite marble shear zone. The oxygen (d18O 28.8-30.7‰) and carbon (d13C 2.6-3.1‰) values of the entire shear zone complex are in the range of unmetamorphosed Mesozoic marine carbonates. However, in the shear zone, areas of small-scale depletions of 18O (D18O up to 1.5‰) are observed, while d13C values remain constant. This oxygen depletion coincides systematically with increasing cathodoluminescence intensity related to lamination pattern (luminescence streaks) oriented parallel to the SZB. The isotopic gradients and the CL variation are probably due to some kind of diffusive mass transfer during dynamic recrystallization produced. No significant geochemical variation exists between the coarse-grained marble protolith and the dynamically recrystallized ultramylonite in the interior of the shear zone. The concentration of trace elements, like Mn (61-188 ppm), Fe (53-369 ppm), and Sr (103-146 ppm) are relatively constant throughout the shear zone complex. No systematic variation of the concentration of Mn (main luminescence activator for calcite) related to the CL intensity can be detected. The geochemical and stable isotope data indicate that the development of the calcite shear zone took place under ‘closed system’ conditions, i.e. without influence of externally derived fluids. Dolomite is absent in the protolith as well as in the protomylonite and only appears within the pervasive dynamically recrystallized calcite ultramylonite; it is presumably related to exsolution reactions occurring during dynamic recrystallization. The angular shape of the dolomite grains points to a brittle rheological behaviour of dolomite during continuous deformation of the calcite matrix. Solvus thermometry indicates that exsolution of dolomite from Mg-calcite with a composition of the protolith (XMgCO3 0.01) will take place at a temperature of about 300-350°C, which seems to be geologically reasonable for the penetrative dynamic recrystallization of calcite in the shear zone.
UnivIS-Import:2015-03-09:Pub.2000.nat.dgeo.IGM.c3tekt.evolut_2

Evolution of kinetics and pore water composition during hydration of a CAC‐Calcite system by addition of Na5P3O10 - Rost, Pauline; Schramm, Tillmann; Götz-Neunhoeffer, Friedlinde (21st ibausil International Conference on Building Materials, 2023)
It was analysed how a low Na5P3O10 (STPP) concentration influences the hydration of a calcium aluminate cement. It is known that the hydration of a CAC-Calcite system precipitates C2AHX as a precursor phase at 23°C during hydration before the formation of hemi- or monocarbonate and the additional formation of CAH10 and AH3. In our study the addition of 0.2 and 1.0 wt.% STPP (bwoc) to a CAC-Calcite system at 23 °C and with a w/b of 0.33 was investigated and is compared with mixes without STPP addition. Heat flow calorimetry data showed that STPP accelerates the main reaction. Moreover, an additional heat flow event within the first 30 minutes was detected by STPP addition. However, from the results of QXRD analysis, crystalline hydrate phases are formed only during the main reaction. These are CAH10, C2AHX, AH3, hemicarbonate and monocarbonate. STPP shows an influence on the amount of crystalline C2AHX, otherwise, no difference in the qualitative phase content is observed. Gillmore-Needle-Testing (IMETER device) could observe an accelerated hardness development during the early heat flow event despite initially reduced viscosity. Pore water studies and thermodynamic modelling (PhreeqC) indicate the formation of an amorphous C-P-H phase during this early heat flow event.<br

Evolution of Magmatism in the New Hebrides Island Arc and in Initial Back-Arc Rifting, SW Pacific - Haase, Karsten; Gress, M. U.; Lima, Selma; Regelous, Marcel; Beier, Christoph; Romer, R. L.; Bellon, H. (Geochemistry Geophysics Geosystems, 2020)
We present new geochemical and isotopic data for rock samples from two island arc volcanoes, Erromango and Vulcan Seamount, and from a 500 m thick stratigraphic profile of lava flows exposed on the SW flank of Vate Trough back-arc rift of the New Hebrides Island Arc (NHIA). The basalts from the SW rift flank of Vate Trough have ages of 0.5 Ma but are geochemically similar to those erupting along the active back-arc rift. The weak subduction component in the back-arc basalts implies formation by decompression melting during early rifting and rifting initiation by tectonic processes rather than by lithosphere weakening by arc magma. Melting beneath Vate Trough is probably caused by chemically heterogeneous and hot mantle that flows in from the North Fiji Basin in the east. The melting zone beneath Vate Trough back-arc is separate from that of the arc front, but a weak slab component suggests fluid transport from the slab. Immobile incompatible element ratios in South NHIA lavas overlap with those of the Vate Trough depleted back-arc basalts, suggesting that enriched mantle components are depleted by back-arc melting during mantle flow. The slab component varies from hydrous melts of subducted sediments in the Central NHIA to fluids from altered basalts in the South NHIA. The volcanism of Erromango shows constant compositions for 5 million years, that is, there is no sign for variable depletion of the mantle or for a change of slab components due to collision of the D'Entrecasteaux Ridge as in lava successions further north.
CRIS-Team Scopus Importer:2020-10-09
Keywords: back-arc basalt; sediment subduction; subduction zone

Evolution of Nb-mineralization in the Chuktukon carbonatite massif, Chadobets upland (Krasnoyarsk Territory, Russia) - Chebotarev, Dmitry; Doroshkevich, Anna G.; Klemd, Reiner; Karmanov, Nikolay (Periodico Di Mineralogia, 2017)
This paper reports on new study of the niobium mineralization of the Chuktukoncarbonatites and weathering crust. The Chuktukon massif is located within the Chadobets upland in the southwestern part of the Siberian Platform. Primary Nb-minerals of carbonatites are pyrochlore group minerals (mainly fluorcalciopyrochlore),newly discovered mineral - rippite [K2(Nb,Ti)2(Si4O12)O(O,F)], and Nb-rutile.Fluorcalciopyrochlore has oscillatory zonation with variations in content of Nb2O5 (59- 67 wt%), TiO2 (2.8-5 wt%), SiO2 (up to 3.3 wt%), CaO (15.9-17.7 wt%), Na2O (7-8.2 wt%) and F (4.5-5.13 wt%). Rippite is Nb-rich silicate ( 44 wt% of Nb2O5) andcontains inclusions of primary fluorcalciopyrochlore. Nb-rutile form oscillatory and sectorial hourglass-like zoned crystals with variable content of Nb2O5 (9-14.7 wt%). The carbonatites underwent strong hydrothermal alteration and subsequent weathering, and, as a result, in the hydrothermally altered carbonatites and weathering crust the primary Nb-minerals become unstable, dissolve and decompose, and Nb-bearing goethite (up to 4.3 wt% of Nb2O5) formed. Primary fluorcalciopyrochlore is replaced by the secondary Sr-, Pb-, LREE- and Ba-rich pyrochlore group minerals.
Keywords: pyrochlore; rippite; rutile; goethite; carbonatite; carbonatite deposit; weathering crust; Krasnoyarsk territory; niobium

Evolution of the Early Paleozoic mélange at the eastern margin of the Argentine Precordillera - von Gosen, Werner; Buggisch, Werner; Lehnert, Oliver (Journal of South American Earth Sciences, 1995)
At the eastern margin of the Argentine Precordillera, Early Paleozoic clastic sediments occur which are interpreted to represent sedimentary mélange deposits of (? Ordovician-) Silurian age. Their olistolith content as well as different pebble types from conglomerate olistoliths provide information about the sedimentary history and the source areas of clastic input during preSilurian times. Gravitational sliding of the olistoliths into an eastern basin was followed by a compressional event during Late Devonian to pre-Upper Carboniferous times. The latter is interpreted to be the result of a ± W-E crustal shortening between the Eastern Precordillera and a basement complex to the east. Late Tertiary compression affected the already steeply inclined and deformed deposits. There was no evidence found to postulate large-scale strike-slip faulting between the Eastern Precordillera and the Sierras Pampeanas Basement Complex during Paleozoic and/or Tertiary times. The formation of both the eastern clastic deposits of the Precordillera and the western slope of the Cambro-Ordovician carbonate platform is interpreted to be the result of large-scale crustal extension with block rotations during Middle to Late Ordovician times. © 1995.
UnivIS-Import:2015-03-05:Pub.1995.nat.dgeo.IGM.LG.evolut

Evolution of the particle size distribution of tricalcium silicate during hydration by synchrotron X-ray nano-tomography - Neubauer, Jürgen; Sowoidnich, T.; Valentini, L.; Schulbert, Christian; Naber, Christoph; Rößler, C.; DaSilva, J.; Bellmann, F. (Cement and Concrete Research, 2022)
The particle size distribution of tricalcium silicate (C3S) is essential for the modelling of early C3S hydration kinetics. In this study, this parameter is analysed during the main hydration period until the first 20 h by synchrotron near-field ptychographic (NF-PXCT) and holographic (HXCT) computed nano-tomography. Additionally, X-ray diffraction, 29Si NMR, thermal analysis, scanning electron microscopy, and inductively coupled plasma-optical emission spectroscopy were used to investigate the system evolution. The time-dependent pore solution composition is also provided to gain further information. HXCT and NF-PXCT show comparable values regarding the evolution of the C3S particle size distribution during hydration, indicating that C3S particles smaller than 1.3 μm are completely dissolved after 20 h of hydration. The results can be reasonably reproduced by numerical models if for all particle sizes a constant reacted rim thickness for each degree of hydration is assumed. Data on the aqueous phase composition are also provided.
CRIS-Team Scopus Importer:2022-03-18
Keywords: Holography (B); Hydration (A); Near-field ptychography (B); Synchrotron nano-tomography (B); Tricalcium silicate (D)

Evolutionszentrum Korallenriff - Kießling, Wolfgang (GIT Labor-Fachzeitschrift, 2010)
Keywords: Riffbiologie; Evolution

Evolving geometries, topologies, and apertures in fracture networks: Quantitative insights from lattice modeling - Mathur, Bakul; Prabhakaran, Rahul; Köhn, Daniel (Forces in Mechanics, 2023)
Fracture networks are crucial in controlling rock mass permeability. Some of the important features of the fracture networks like the density, interconnectivity, spatial distribution, and fracture apertures determine the success of the subsurface operations. Fracture networks can be studied with analogue studies, physical experiments, and numerical modeling. In this study, we analyse the evolution of a two-dimensional fracture network under gravitational and shear loads using the lattice modeling capabilities of the microstructural modeling environment “Elle”. The simulation cases include varying gravitational loads and Young's moduli of the formations. The topological progression of the modeled fracture network from isolated to interconnected nodes depicts a realistic network evolution process. The study shows that the rock stiffness exhibits a direct correlation with the number of fractures influencing the average aperture size of the network. A higher gravity load resulted in the development of a sparse fracture network. Stiffer rock models also showed an early onset of fracturing.
CRIS-Team Scopus Importer:2023-06-30
Keywords: Aperture; Elle; Fracture; Lattice; Network

Exceptional bryozoan assemblage of a microbial-dominated reef from the early Wenlock of Gotland, Sweden - Ernst, Andrej; Munnecke, Axel; Oswald, Irina (Gff, 2015)
Eleven bryozoan species were described from Nors Stenbrott (Gotland, Sweden), represented by six trepostomes, four cystoporates and one fenestrate. Three genera with three species are new: two cystoporates Acantholunaria expansa gen. n. sp. n. and Curviporamonostylata gen. n. sp. n., and a trepostome Stellatotrypa hirsuta gen. n. sp. n. Two trepostome species are new: Leptotrypa perforata sp. n. and Leptotrypa enodis sp. n. The described bryozoan fauna is dominated by thin encrusting taxa which are involved in intensive interactions with calcimicrobes in bryozoan-microbial crusts in the reef. The bryozoan-microbial crusts (bryoliths) show certain sequences by microbes, encrusting bryozoans and tabulate corals. Multiple self-overgrowth of bryozoans occurs frequently and is interpreted as a defensive tactic against microbial fouling. Bryozoans avoid vicinity to tabulate corals, apparently due to strong competition for substrate. The bryozoan fauna from Nors Stenbrott is highly endemic, only two species are known elsewhere (North America and Great Britain).
Keywords: taxonomy; bryozoa; Gotland; Silurian; reefs; palaeoecology

Exceptional cameral deposits in a sublethally injured Carboniferous orthoconic nautiloid from the Buckhorn Asphalt Lagerstätte in Oklahoma, USA - Seuß, Barbara; Mapes, Royal H.; Klug, Christian; Nützel, Alexander (Acta Palaeontologica Polonica, 2012)
The cameral and intrasiphonal deposits of a Pennsylvanian straight nautiloid (Pseudorthoceratidae) are studied in order to understand the formation of these deposits. The specimens from the Buckhorn Asphalt deposit (Oklahoma) are exceptionally preserved including original aragonite and microstructures. The specimen investigated survived a predation attempt and shows bite marks on the phragmocone. This is the second report of an ectocochleate cephalopod and first report of an orthoconic nautiloid which survived massive damage of conch and siphuncle. For the first time, a high-magnesium calcitic mineralogy of cameral deposits is documented. These deposits were formed in alternation with aragonite in a chamber which was perforated during the unsuccessful predation attempt. The animal formed the chamber deposits throughout its entire lifetime and the siphuncle played a major role in formation of the cameral deposits.
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LP.except
Keywords: Buckhorn Asphalt; cameral deposits; Carboniferous; high Mg-calcite (HMC); Nautiloidea; North America; Oklahoma; predation; Pseudorthoceratidae; sublethal damage

Exceptionally low mercury concentrations and fluxes from the 2021 and 2022 eruptions of Fagradalsfjall volcano, Iceland - Edwards, Brock A.; Pfeffer, Melissa A.; Ilyinskaya, Evgenia; Kleine-Marshall, Barbara; Mandon, Céline L.; Cotterill, Adam; Aiuppa, Alessandro; Outridge, Peter M.; Wang, Feiyue (Science of the Total Environment, 2024)
Mercury (Hg) is naturally released by volcanoes and geothermal systems, but the global flux from these natural sources is highly uncertain due to a lack of direct measurements and uncertainties with upscaling Hg/SO2 mass ratios to estimate Hg fluxes. The 2021 and 2022 eruptions of Fagradalsfjall volcano, southwest Iceland, provided an opportunity to measure Hg concentrations and fluxes from a hotspot/rift system using modern analytical techniques. We measured gaseous Hg and SO2 concentrations in the volcanic plume by near-source drone-based sampling and simultaneous downwind ground-based sampling. Mean Hg/SO2 was an order of magnitude higher at the downwind locations relative to near-source data. This was attributed to the elevated local background Hg at ground level (4.0 ng m−3) likely due to emissions from outgassing lava fields. The background-corrected plume Hg/SO2 mass ratio (5.6 × 10−8) therefore appeared conservative from the near-source to several hundred meters distant, which has important implications for the upscaling of volcanic Hg fluxes based on SO2 measurements. Using this ratio and the total SO2 flux from both eruptions, we estimate the total mass of gaseous Hg released from the 2021 and 2022 Fagradalsfjall eruptions was 46 ± 33 kg, equivalent to a flux of 0.23 ± 0.17 kg d−1. This is the lowest Hg flux estimate in the literature for active open-conduit volcanoes, which range from 0.6 to 12 kg d−1 for other hotspot/rift volcanoes, and 0.5–110 kg d−1 for arc volcanoes. Our results suggest that Icelandic volcanic systems are fed from an especially Hg-poor mantle. Furthermore, we demonstrate that the aerial near-source plume Hg measurement is feasible with a drone-based active sampling configuration that captures all gaseous and particulate Hg species, and recommend this as the preferred method for quantifying volcanic Hg emissions going forward.
CRIS-Team Scopus Importer:2024-02-16
Keywords: Drones; Hg/SO; Natural emissions; Sulfur dioxide; Volcanic emissions

Exceptional preservation of bryozoans from the Buckhorn Asphalt Quarry, Oklahoma, USA - Seuß, Barbara; Ernst, Andrej; Taylor, Paul; Nützel, Alexander (Jahrestagung der Paläontologischen Gesellschaft, 2016)
The Pennsylvanian (Desmoinesian–Virgilian) Buckhorn Asphalt Quarry in Oklahoma, USA is well known for its exceptional preservation of a diverse marine invertebrate fauna. Results from the latest study focusing on the Buckhorn bryozoans are presented. Nine genera and species are recognized, two of them new (Stenophragmidium buckhornensis and Streblotrypa (S.) heltzelae). Some skeletal characteristics that are usually lost during diagenesis are uniquely preserved. These include small to large (5-50µm in diameter) node-like surface expressions of styles that most likely strengthened the skeleton or were for attachment of the soft tissue rather than defense. ‘Nanoperforations’ observed in Streblotrypa (Streblotrypa) heltzelae, Stenophragmidium buckhornensis and Rhombocladia delicatula are tiny holes with a diameter of only 0.5 µm countersunk into the laminated skeletal walls. Such structures are unknown from other bryozoans (recent and fossil) and their genesis – produced by microendoliths or by the bryozoans themselves? – is unclear. The most likely hypothesis is that they are due to symbionts (e.g. bacteria) that lived embedded in the growing walls of the bryozoan zooids. In fractured branches of S. (S.) heltzelae, closely spaced ‘granule’ bands on the walls of the autozooids were found. Again, such structures have not been observed elsewhere and their origin and function are enigmatic. Mural spines are reported from R. delicata and Stenoporella sp. Spinose hemiphragms in some trepostomes are new features of unknown function. Finally, a transverse fibrous fabric found in the fenestrate Septopora blanda is reminiscent of a fabric common in post-Palaeozoic cyclostome bryozoans but hitherto not reported in palaeostomates from the Palaeozoi

Exceptional preservation of Carboniferous bryozoans in the Buckhorn Asphalt Quarry of Oklahoma, USA - Taylor, Paul; Seuß, Barbara; Ernst, Andrej (13th Larwood Symposium, 2015)
The Late Carboniferous Buckhorn Asphalt Quarry exposes an ‘Impregnation Fossil Lagerstätte’ (Seuss et al. 2009), famous for its high-quality preservation of molluscs and other fossils. Some of the fossils conserve pristine aragonite or high-Mg calcite, mineral phases seldom preserved in Palaeozoic deposits. Located 10 km south of Sulphur, Oklahoma, the Buckhorn Asphalt Quarry was worked commercially in the 1920s and 1930s for road-paving asphalt. The Buckhorn Asphalt Quarry deposit comprises mixed siliciclastic–carbonate, mostly shallow-water sediments belonging to the Boggy Formation (Deese Group). The impregnating asphalt was derived from hydrocarbons that migrated into the sediments during or shortly after deposition, infilling pore spaces, sealing the sediment and fossils from circulating pore waters and inhibiting diagenesis and cementation. Although bryozoans have been recorded previously from the Buckhorn Asphalt Quarry, they have never been studied in any detail. The fauna is dominated by rhabdomesine cryptostomes and trepostomes, with fewer fenestrates. Chambers of the zooids are largely empty of sediment or cement, which has enabled the observation of some enigmatic internal skeletal features under SEM. For instance, transverse rows of granules line the chambers of the rhabdomesine Streblotrypa, and the hemiphragms of a tabuliporid trepostome have peculiar spinose outgrowths on their proximal edges. Also puzzling is the occurrence in several species of submicron-sized pits on internal wall surfaces. Although superficially resembling microendoliths (Wisshak et al. 2008), the pits may be too small for such an origin to be correct (M. Wisshak, pers. comm.), and the laminae of the bryozoan skeletons appear to be deflected around them suggesting formation during the growth of the host bryozoan skeleton

Exceptional Preservation of Molluscs in the Buckhorn Asphalt - Seuß, Barbara; Nützel, Alexander; Schulbert, Christian (World Congress of Malacology, 2007)
The Late Carboniferous (Desmoinesian, approx. 306 m years) sediments of the Buckhorn Asphalt Quarry (Oklahoma, USA) contain the best preserved Palaeozoic mollusc fauna world wide. Molluscs are commonly preserved in original aragonite including shell microstructures, though aragonite is normally dissolved or recrystallised shortly after deposition. Even larval shells and colour patterns are preserved. The good preservation of fossils was caused by Ordovician oil which intruded into the sediments simultaneously to or shortly after deposition, sealing pore space and preventing recrystallisation via circulating pore waters. The oil then transformed into asphalt loosing its volatiles. The fauna of the Buckhorn Asphalt is dominated by mollusc species, especially by cephalopods and small gastropods. For the purpose of inferring the depositional environment and Palaeoecology, thin sections were prepared from samples of all main lithologies. Asphaltic rocks were dissolved in a Soxhlet apparatus using methylene chloride as solvent (asphalt content is up to 20%). The dissolved samples were sieved (2 mm, 500 µm, 125 µm) and picked. Fossils, especially small gastropods were documented with SEM- and light microscope pictures. Bioerosion in the Buckhorn fossils is common and could be proved using SEM-photographs of fossils and casts, as well as with thin sections. At least 50 gastropod species, two coiled and three orthocone nautiloids have been documented, however brachiopods and bivalves are rare. The rich marine fauna is furthermore represented by ostracods, foraminifers, echinoderms, and bryozoans. Vertebrate remains like fish teeth are rare. First results suggest that most fossils lived in shallow water as is indicated by a diverse assemblage of bioeroders within the mollusc shells as well as by the presence of large land plant remains. The fossil material is mixed with siliciclastic sediment which is conglomeratic sometimes, and was transported over a relatively steep slope or in channel

Exceptional Preservation of Molluscs in the Buckhorn Asphalt - Seuß, Barbara; Nützel, Alexander; Schulbert, Christian (Annual Meeting of the Paläontologische Gesellschaft, 2007)
The Late Carboniferous Buckhorn Asphalt Quarry contains the best preserved Palaeozoic molluscs known world wide. The molluscs are commonly present in their original aragonitic preservation. Shell microstructures, larval shells, and colour patterns are commonly preserved. The good preservation of the fossil molluscs from the Buckhorn Asphalt was caused by Ordovician oil intruding the sediments simultaneously to or short after deposition, sealing pore space and preventing recrystallisation. The oil transformed into asphalt loosing its volatiles. The fauna of the Buckhorn Asphalt Quarry is dominated by molluscs, especially by cephalopods and small gastropods. The great abundance of molluscs and the unique preservation make the Buckhorn Asphalt one of the most important fossil Lagerstätten for Palaeozoic molluscs. The Buckhorn Asphalt Quarry is located near Sulphur, Oklahoma (USA), in the Arbuckle Mountains. It exposes a suite of clastic Carboniferous sediments including siliciclastic limestones, mollusc coquinas, conglomerates, and sandstones. The mollusc bearing sediments from the Buckhorn Asphalt Quarry are of Late Carboniferous (Desmoinesian, 308 - 306.5 Ma) age. Deposition of the sediments took place near the palaeoequator during that time. For documentation from which facies the fossils derive thin section were prepared. The high asphalt amount made is necessary to impregnate the rock samples with synthetic resin before preparing the thin section. To remove the asphalt of the samples and dissolve them a Soxhlet apparatus had to be used. Dissolved sediments were further disaggregated with tensides to remove hydrophobic matter, and then the material was wet-sieved. The fossils of the Buckhorn Asphalt Quarry allowed us to study a unique Palaeozoic assemblage of microborers which were studied in thin sections, casts and etchings. It turned out, that the detected ichno-fossils represent the most diverse Palaeozoic assemblage of micro-bioeroders proved yet. The Buckhorn Asphalt Quarry is an outstanding source of information, as it is one of the very few Palaeozoic deposits in which mollusc shells are preserved in almost unaltered composition. Original shell structures and mineralogy, protoconchs or prodissoconchs are commonly preserved. Colour preservation of naticopsids is present. Gastropods ( 50 species) are the most diverse group in the faunal assemblage. Ammonites and nautiloids are very abundant, bivalves are common. Moreover, a rich marine invertebrate fauna including e.g. brachiopods, echinoderms, bryozoans, ostracods, foraminifera is present. Vertebrate remains are rare, remains of land plants are up to several decimetres in size. The exceptional preservation mollusc shells provides a “preservational window“ for studying a Late Palaeozoic microboring assemblage revealing a total of 18 known ichnospecies and the new ichnotaxon Aurimorpha varia – the most diverse Palaeozoic microboring assemblage known to date. First results suggest that most fossils including the gastropods lived in shallow water as is indicated by the diverse assemblage of bioeroders within the mollusc shells as well as by the presence of large plant remains. The fossil material was mixed with siliciclastic sediment, some of them conglomeratic, and transported over a relatively steep slope or in channels by mass flow events. Data about early ontogenetic mollusc shells and shell microstructure provide important information for phylogeny and taxonomy. We can also study heterochronic processes and compare larval and adult shell morphologies. The fact that shells are commonly unaltered by diagenesis and are present in their original mineralogical composition allows the study of original isotope signals in order to reconstruct palaeo-environmental condition

Exceptions to the temperature–size rule: no Lilliput Effect in end-Permian ostracods (Crustacea) from Aras Valley (northwest Iran) - Nätscher, Paulina; Gliwa, Jana; de Baets, Kenneth; Ghaderi, Abbas; Korn, Dieter (Palaeontology, 2023)
The body size of marine ectotherms is often negatively correlated with ambient water temperature, as seen in many clades during the hyperthermal crisis of the end-Permian mass extinction (c. 252 Ma). However, in the case of ostracods, size changes during ancient hyperthermal events are rarely quantified. In this study, we evaluate the body size changes of ostracods in the Aras Valley section (northwest Iran) in response to the drastic warming during the end-Permian mass extinction at three taxonomic levels: class, order, species. At the assemblage level, the warming triggers a complete species turnover in the Aras Valley section, with larger, newly emerging species dominating the immediate post-extinction assemblage for a short time. Individual ostracod species and instars do not show dwarfing or a change in body size as an adaptation to the temperature stress during the end-Permian crisis. This may indicate that the ostracods in the Aras Valley section might have been exceptions to the temperature–size rule (TSR), using an adaptation mechanism that does not involve a decrease in body size. This adaptation might be similar to the accelerated development despite constant instar body sizes that can be observed in some recent experimental studies of ostracod responses to thermal stress.
CRIS-Team Scopus Importer:2023-08-11
Keywords: Aras Valley section; body size; mass extinction; Ostracoda; Permian–Triassic

Excursion H: The Buntsandstein of the Hessian Depresion: Contrasting styles of basinal and marginal deposition. - Lepper, Jochen; Röhling, Heinz-Gerd; Stollhofen, Harald; Tietze, Klaus-Werner (Epicontinental Triassic International Symposium, Halle/S., 21.09.-23.09.1998, 1998)
UnivIS-Import:2015-03-05:Pub.1998.nat.dgeo.IGM.LG.thebun

Exkursion 5: Rotliegend-Schwemmfächersysteme im Saar-Nahe-Becken. - Stollhofen, Harald (Sediment 2004, 31.05.-06.06.2004 in Aachen, Tagungsband, 2004)
UnivIS-Import:2015-04-20:Pub.2004.nat.dgeo.IGM.LG.rotlie

Experimental and quantum chemical study оn the DNA/protein binding and the biological activity of a rhodium(iii) complex with 1,2,4-triazole as an inert ligand - Petrović, Angelina; Živanović, Marko; Puchta, Ralph; Ćoćić, Dušan; Scheurer, Andreas; Milivojevic, Nevena; Bogojeski, Jovana (Dalton Transactions, 2020)
The synthesis and structural characterization of a newly synthesized mononuclear rhodium(iii) complex, Rhtrz, with a ligand (2,2,6-bis((4S,7R)-7,8,8-trimethyl-4,5,6,7-tetrahydro-1H-4,7-methanoindazol-3-yl)pyridine) and a ligand of 1,2,4-triazole, are presented in this paper. The kinetic interactions of the Rhtrz complex with essential biomolecules such as 5-GMP, L-Met, and GSH were examined. The study of the biological interactions was focused on the binding properties of the Rhtrz complex with CT-DNA and serum albumin. These interactions were investigated using UV-vis spectrophotometry, fluorescence spectroscopy, viscosity measurements, thermal denaturation studies, and electrophoresis. Fluorescence competition experiments with site-markers for BSA were used to locate the binding site of the Rhtrz-complex to the BSA. Molecular docking studies were carried out to obtain detailed binding information of the complex with CT-DNA, BSA, and HSA. Furthermore, the apparent distance between the donor (HSA) and acceptor (Rhtrz) was determined using fluorescence resonance energy transfer (FRET). The thermodynamic properties and relative stabilities of the Rhtrz complex were examined, constructing the two model equation by DFT calculations (B3LYP(CPCM)/LANL2DZp). In vitro cytotoxicity and redox status on the human epithelial colorectal cancer cell line (HCT-116) and healthy human fibroblast cell line (MRC-5) were also investigated.
CRIS-Team Scopus Importer:2020-07-03

Experimental investigation of a borehole field by enhanced geothermal response test and numerical analysis of performance of the borehole heat exchangers - Luo, Jin; Xiang, Wei; Bayer, Manfred; Prieß, Anna; Wilkmann, Lucas; Steger, Hagen; Zorn, Roman; Rohn, Joachim (Energy, 2015)
Keywords: BHE (borehole heat exchanger); EGRT (enhanced geothermal response test); GSHP (ground source heat pump) system; Layered subsurface; Thermal conductivity

Experimental investigation of the hydraulic and heat-transfer properties of artificially fractured granite - Luo, Jin; Zhu, Yongqiang; Guo, Qinghai; Tan, Long; Zhuang, Yaqin; Liu, Mingliang; Zhang, Canhai; Xiang, Wei; Rohn, Joachim (Scientific Reports, 2017)
In this paper, the hydraulic and heat-transfer properties of two sets of artificially fractured granite samples are investigated. First, the morphological information is determined using 3D modelling technology. The area ratio is used to describe the roughness of the fracture surface. Second, the hydraulic properties of fractured granite are tested by exposing samples to different confining pressures and temperatures. The results show that the hydraulic properties of the fractures are affected mainly by the area ratio, with a larger area ratio producing a larger fracture aperture and higher hydraulic conductivity. Both the hydraulic apertureand the hydraulic conductivity decrease with an increase in the confining pressure. Furthermore, the fracture aperture decreases with increasing rock temperature, but the hydraulic conductivity increases owing to a reduction of the viscosity of the fluid flowing through. Finally, the heat-transfer efficiency of the samples under coupled hydro-thermal-mechanical conditions is analysed and discussed. © The Author(s) 2017.

Experimental study of road deicing by using the urban groundwater under the climatic condition of Nuremberg city, Germany - Baumgärtel, Sebastian; Rohn, Joachim; Luo, Jin (SN Applied Sciences, 2020)
Traffic accidents caused by heavy icing and snowing kept increasing in Germany in recent years, and many deicing methods were therefore developed. These methods either harm the environment (deicing salt) or damage roads (snowplows). As an alternative, the heating of roads using electricity or heated water has been proposed. This study considers the direct use of groundwater for road deicing in urban centers. The climatic and hydrological setting of Nuremberg city is referenced for a testing setup inside a cooling chamber using concrete slabs to test inlet water temperatures under different ambient temperatures. They were designed with 100 mm and 200 mm coil distance and both with an installation depth of around 40 mm. Additionally, an outside test field in a similar fashion is built to validate the measurements inside a chamber. The experiments indicated that a groundwater temperature of 10 degrees C is sufficient to keep the surface ice-free in typical winter days in the study area. Furthermore, the snow did not accumulate on the outside test field during snowfall events. The usability of this heating method could, therefore, be recommended for road deicing under such climatic condition.
CRIS-Team WoS Importer:2020-06-16

Exploring the Ar isotope record of an early Miocene pseudotachylyte in an early Oligocene intrusion (Rieserferner pluton, eastern Alps) - Di Vincenzo, Gianfranco; Pennacchioni, Giorgio; Bestmann, Michel (Lithos, 2019)
We investigate the influence of unmelted clasts on the 40 Ar[sbnd] 39 Ar age record of a Miocene pseudotachylyte within the early Oligocene Riesenferner pluton (eastern Alps). This case study is ideal to investigate the effect of inherited Ar retained in survivor clasts because, although seismic faulting was only slightly younger (<20 Ma) than the igneous source rock, the pseudotachylyte includes layers with significant variations in K content, of either dominant plagioclase and biotite microlites or dominant submicrometric muscovite matrix. Numerical modeling, assuming pure diffusive loss and a short-lived thermal pulse due to frictional heating, indicates that unmelted plagioclase clasts represent the most critical issue in interpreting Ar data. Plagioclase clasts of only a few to tens micrometers in size are expected to retain most of radiogenic Ar accumulated before coseismic faulting. A comparable behavior is only predicted for much larger (ten to fifty times larger) K-feldspar clasts. In-situ 40 Ar[sbnd] 39 Ar laser analyses of low-K microlitic domains, free of discernable clasts, yield slightly, but significantly, older ages than those from the high-K matrix. Results suggest that older ages (up to 4% on average) from low-K domains are due to contamination by plagioclase clasts and suggest an age of 17.12 ± 0.22 Ma for coseismic slip. This age dates the last stage of activity of the Giudicarie Fault during tectonic indentation of the Dolomites block of the southern Alps against the nappe stack of the eastern Alps.
CRIS-Team Scopus Importer:2019-05-02
Keywords: Microstructural analysis; Numerical modeling; Pseudotachylyte; Rieserferner pluton (eastern Alps)

Exploring the limits of morphospace: Ontogeny and ecology of late Viséan ammonoids from the Tafilalt, Morocco - Klug, Christian; de Baets, Kenneth; Korn, Dieter (Acta Palaeontologica Polonica, 2016)
Early late Visean ammonoid assemblages in Morocco are composed of diverse and well-preserved specimens. The material was found in a plain in the Tafilalt (eastern Anti-Atlas). Here, we describe mass-occurrences of juvenile specimens, in which subadult and adult specimens occur in low numbers. The juveniles of some species display a conch morphology that differs fundamentally from the adult stages. Accordingly, we emend the species diagnoses of Goniatites lazarus as well as Calygirtyoceras darkaouaense, introduce the species Entogonites bucheri sp. nov., and discuss possible ecological implications of the morphologic changes throughout ontogeny. In particular, we compare the changes in conch morphology through ontogeny in the light of Pareto Optimiality according to which the morphology of organisms would fill a polygon or polyhedron in morphospace. Data points in one of the vorteces of the polyhedron indicate optimisation for the corresponding task. Although shape is not a proof of function, it appears plausible that juvenile conchs were selected rather for compactness while adult conchs were positively selected for conchs with improved hydrodynamic properties. This appears plausible because at small conch diameters, swimming movements will not suffice for effective translocation and a planktonic mode of life is likely.
Keywords: Ammonoidea; morphospace; palaeoecology; Visean; Morocco

Exploring the oxygen and carbon isotopic composition of the Mediterranean red coral (Corallium rubrum) for seawater temperature reconstructions - Chaabane, Sonia; López Correa, Matthias; Montagna, Paolo; Kallel, Néjib; Taviani, Marco; Linares, Christina; Ziveri, Patrizia (Marine Chemistry, 2016)
Here we provide first evidence that the stable oxygen and carbon isotopic composition (δ18O, δ13C) of the high-magnesium calcite skeleton red coral Corallium rubrum can be used as a reliable seawater temperature proxy. This is based upon the analyses of living colonies of C. rubrum from different depths and localities in the Western Mediterranean Sea. The assessment of the growth rates has been established through the analysis of growth band patterns. The δ18O and δ13C compositions show large variability with a significant difference between the branches and the bases of the colonies. In both coral portions, the δ18O and δ13C values are highly correlated and show well-defined linear trends. Following the “lines technique” approach developed by Smith et al. (2000) for scleractinian aragonitic deep-water corals, our data have been combined with published values for the deep-sea gorgonian corals Isididae and Coralliidae from Kimball et al. (2014) and Hill et al. (2011) resulting in the following δ18O temperature equation:T°C=−5.05±0.24×δ18Ointercept+14.26±0.43R2=0.962pvalue<0.0001 The error associated with this equation is ± 0.5 °C at the mean temperature of the data set, ± 0.7 °C for corals living in 2 °C water and ± 1 °C for coral living in warmer water (17 °C). The highly significant δ18Ointercept vs. temperature relationship combined with the “lines technique” method can be reliably applied to the calcitic skeleton to obtain calcification temperature estimates in the past, although this approach requires the knowledge of the past δ18O and δ13C composition of seawater and it is labor and time intensive.
UnivIS-Import:2017-01-09:Pub.2016.nat.dgeo.IGM.LP.explor_8
Keywords: Growth rings; Mediterranean Sea; Red coral; Seawater temperature; δ; δ

Exposure Assessment of Fluoride Intake Through Commercially Available Black Tea (Camellia sinensis L.) from Areas with High Incidences of Chronic Kidney Disease with Undetermined Origin (CKDu) in Sri Lanka - Chandrajith, Rohana; Bhagya, Sachini; Diyabalanage, Saranga; Wimalasiri, Swarna; Ranatunga, Mahasen A.B.; Barth, Johannes (Biological trace element research, 2021)
Fluoride is a beneficial trace element for human health as its deficiency and excess levels can cause detrimental health effects. In Sri Lanka, dry zone regions can have excessive levels of fluoride in drinking water and can cause dental and skeletal fluorosis. In addition to drinking water, traditional habits of tea consumption can cause an additional intake of fluoride in the population. A total number of 39 locally blended black tea samples were collected from a village where chronic kidney disease with undetermined origin (CKDu) is prevalent. In addition, unblended tea samples were obtained from tea-producing factories. The fluoride contents in infusions of 2% weight per volume (w/v) were measured using calibrated ion-selective fluoride electrodes. The mean fluoride content was 2.68±1.03 mg/L in loose tea, 1.87±0.57mg/L in packed tea samples, and 1.14±0.55 mg/L in unblended tea. Repeated brewing of the same tea leaves showed that over 50% of fluoride leached into the solution in the first infusion. An estimate of the daily total average fluoride intake via tea consumption per person is 2.68 mg per day. With groundwater in many dry zone regions in Sri Lanka showing high fluoride levels that exceed 0.5 mg/L, the additional daily intake can rapidly exceed recommended thresholds of 2 mg/day. This can add to adverse health impacts that might also relate to CKDu.
CRIS-Team Scopus Importer:2021-04-16
Keywords: CKDu; Dental fluorosis; Dry zone; Fluoride in tea leaves; Repeated infusion; Tea infusion

Extended abstract - Sauk megasequence supersequences, southern Great Basin: Second-Order accomodation events in the southwestern Cordilleran margin plattform. In Derby, J.R., Fritz, R.D., Longacre, S., Morgan, W.A. & Sternbach, C.A.: The great American carbonate bank: The Geology and economic resources of the Cambrian-Ordovician Sauk megasequence of Laurentia. - Keller, Martin; Cooper, John D.; Lehnert, Oliver (AAPG Memoir, 2012)
UnivIS-Import:2015-03-09:Pub.2012.nat.dgeo.IGM.LG.extend

External forcing controls on sandstone diagenesis - Caracciolo, Luca; Janßen, Meike; Ravidà, Domenico; Bonnell, L.; Heins, W.; Lander, R.; Stollhofen, Harald (ResTech 2020, 2020)
CRIS-Team Scopus Importer:2020-12-18

Extinction and dawn of the modern world in the Carnian (Late Triassic) - Dal Corso, Jacopo; Bernardi, Massimo; Sun, Yadong; Song, Haijun; Seyfullah, Leyla J.; Preto, Nereo; Gianolla, Piero; Ruffell, Alastair; Kustatscher, Evelyn; Roghi, Guido; Merico, Agostino; Hohn, Sönke; et al. (Science Advances, 2020)
The Carnian Pluvial Episode (Late Triassic) was a time of global environmental changes and possibly substantial coeval volcanism. The extent of the biological turnover in marine and terrestrial ecosystems is not well understood. Here, we present a meta-analysis of fossil data that suggests a substantial reduction in generic and species richness and the disappearance of 33% of marine genera. This crisis triggered major radiations. In the sea, the rise of the first scleractinian reefs and rock-forming calcareous nannofossils points to substantial changes in ocean chemistry. On land, there were major diversifications and originations of conifers, insects, dinosaurs, crocodiles, lizards, turtles, and mammals. Although there is uncertainty on the precise age of some of the recorded biological changes, these observations indicate that the Carnian Pluvial Episode was linked to a major extinction event and might have been the trigger of the spectacular radiation of many key groups that dominate modern ecosystems.
CRIS-Team Scopus Importer:2020-09-25

Extinction and recovery patterns of scleractinian corals at the Cretaceous-Tertiary boundary - Kießling, Wolfgang; et al. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2004)
The extinction and recovery of scleractinian corals at the Cretaceous-Tertiary (K-T) boundary was analyzed based on a global database of taxonomically revised late Campanian to Paleocene coral collections. In contrast to earlier statements, our results indicate that extinction rates of corals were only moderate in comparison to other marine invertebrates. We have calculated a 30% extinction rate for Maastrichtian coral genera occurring in more than one stratigraphic stage and more than one geographic region. Reverse rarefaction suggests that some 45% of all coral species became extinct. Photosymbiotic (zooxanthellate) corals were significantly more affected by the extinction than azooxanthellate corals; colonial forms were hit harder than solitary forms, and among colonial forms an elevated integration of corallites raised extinction risk. Abundance, as measured by the number of taxonomic occurrences, had apparently no influence on survivorship, but a wide geographic distribution significantly reduced extinction risk. As in bivalves and echinoids neither species richness within genera nor larval type had an effect on survivorship. An indistinct latitudinal gradient is visible in the extinction, but this is exclusively due to a higher proportion of extinction-resistant azooxanthellate corals in higher-latitude assemblages. No significant geographic hotspot could be recognized, neither in overall extinction rates nor in the extinction of endemic clades. More clades than previously recognized passed through the K-T boundary only to become extinct within the Danian. These failed survivors were apparently limited to regions outside the Americas. Recovery as defined by the proportional increase of newly evolved genera, was more rapid for zooxanthellate corals than previously assumed and less uniform geographically than the extinction. Although newly evolved Danian azooxanthellate genera were significantly more common than new zooxanthellate genera, the difference nearly disappeared by the late Paleocene suggesting a more rapid recovery of zooxanthellate corals in comparison to previous analyses. New Paleocene genera were apparently concentrated in low latitudes, suggesting that the tropics formed a source of evolutionary novelty in the recovery phase. © 2004 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2004.nat.dgeo.IGM.LP.extinc
Keywords: Corals; Cretaceous-Tertiary boundary; Evolution; Mass extinction; Reefs

Extinction risk controlled by interaction of long-term and short-term climate change - Mathes, Gregor; van Dijk, Jeroen; Kießling, Wolfgang; Steinbauer, Manuel J. (Nature Ecology & Evolution, 2021)
Assessing extinction risk from climate drivers is a major goal of conservation science. Few studies, however, include a long-term perspective of climate change. Without explicit integration, such long-term temperature trends and their interactions with short-term climate change may be so dominant that they blur or even reverse the apparent direct relationship between climate change and extinction. Here we evaluate how observed genus-level extinctions of arthropods, bivalves, cnidarians, echinoderms, foraminifera, gastropods, mammals and reptiles in the geological past can be predicted from the interaction of long-term temperature trends with short-term climate change. We compare synergistic palaeoclimate interaction (a short-term change on top of a long-term trend in the same direction) to antagonistic palaeoclimate interaction such as long-term cooling followed by short-term warming. Synergistic palaeoclimate interaction increases extinction risk by up to 40%. The memory of palaeoclimate interaction including the climate history experienced by ancestral lineages can be up to 60 Myr long. The effect size of palaeoclimate interaction is similar to other key factors such as geographic range, abundance or clade membership. Insights arising from this previously unknown driver of extinction risk might attenuate recent predictions of climate-change-induced biodiversity loss.
CRIS-Team WoS Importer:2021-02-12

Extinction trajectories of benthic organisms across the Triassic-Jurassic boundary - Kießling, Wolfgang; Aberhan, Martin; Brenneis, Benjamin; Wagner, Peter (Palaeogeography, Palaeoclimatology, Palaeoecology, 2007)
We analysed diversity and abundance patterns of benthic organisms across the Triassic-Jurassic (T-J) boundary based on the Paleobiology Database (PBDB), which compiles palaeontological collection data on a global scale. While Sepkoski's [Sepkoski, J.J. Jr., 2002. A compendium of fossil marine animal genera. Bulletins of American Paleontology 363, 1-563] compendium on the stratigraphic ranges of marine animal genera suggests that the dominant macrobenthic groups of the Late Triassic experienced significant extinctions prior to the T-J boundary, a significant end-Triassic extinction peak is evident from PBDB's data. This Rhaetian extinction peak is found in both an analysis of the raw data of stratigraphic ranges and a sample-standardized analysis of occurrence data; 41% of all mesobenthic and macrobenthic genera crossing the Norian-Rhaetian boundary became extinct within the Rhaetian. Although this rate suffices to characterize the end-Triassic extinction as a true mass extinction against a Middle Triassic to Middle Jurassic background, significantly reduced Rhaetian origination rates add to the strong diversity depletion in the earliest Jurassic. As for other mass extinctions, evidence for selective extinction is meagre when the analysis is limited to the boundary interval alone and when focused on taxonomic and ecological characteristics of individual genera. When taxa are separated by environmental preferences, however, several determinants of extinction risk become evident, suggesting that reef dwellers had a significantly higher extinction risk than level-bottom dwellers, taxa with an inshore preference were more strongly affected than offshore taxa, taxa preferring carbonate substrates were more strongly hit than taxa preferring siliciclastic substrates and taxa preferentially inhabiting low latitudes had higher extinction rates than taxa more common at intermediate and high latitudes. Much of this selectivity is not independent and also seen in the intervals of background extinctions suggesting that the end-Triassic mass extinction represents an intensification of background extinctions but not a qualitatively different macroevolutionary regime. One possible exception is related to preferences for depositional environments suggesting a selective Rhaetian extinction in reefs and inshore settings. © 2006 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LP.extinc
Keywords: Jurassic; Level-bottom communities; Mass extinctions; Reefs; Rhaetian; Selectivity; Triassic

Extreme geochemical heterogeneity beneath the North Tonga Arc: Interaction of a subduction zone with intraplate seamount chains - Storch, Bettina; Regelous, Marcel; Nöbel, Kristina; Haase, Karsten; Bauer, Julia (Chemical Geology, 2022)
We provide new geochemical and isotope data for lavas from six young submarine volcanoes from the northernmost oceanic Tonga island arc. These lavas have low concentrations of moderately incompatible trace elements, but are enriched in Nb and Ta compared to all other Tonga island arc lavas, and their Nd, Hf and Pb isotope compositions resemble those of rejuvenated lavas from the nearby Samoa hotspot. These unusual compositions indicate that the mantle source of North Tonga lavas was depleted by prior melting events, before re-enrichment by a partial melt enriched in highly incompatible elements with Nd, Hf and Pb isotope compositions similar to Samoan intraplate lavas. Samoa plume mantle is flowing southwards beneath the northern Tonga island arc and Lau Basin, in part guided by rifting of the Tonga plate lithosphere. A fluid component was later added from a mixture of subducted pelagic sediment and subducting Louisville Seamount Chain volcanic material. Our new data show that the Louisville component is only found in lavas from volcanoes occurring along ∼100 km of the arc front, indicating that the oceanic crust loses Pb by dehydration over a relatively small depth interval during subduction. The compositions of lavas from the northern Tonga island arc are therefore influenced by material from two hotspots; southwards inflow of mantle from the active Samoa plume beneath the arc within the past 6 Ma, and a subduction component from >80 Ma old subducted Louisville Seamount Chain basalts.
CRIS-Team Scopus Importer:2022-06-03
Keywords: Hf-; High field strength elements; Louisville Seamount Chain; Nd- and double spike Pb-isotopes; Northernmost Tonga island arc; Samoa plume; Sr-; Tonga subduction system

Extreme gradients in CO2 losses downstream of karstic springs - Lee, Kern Y.; van Geldern, Robert; Barth, Johannes (Science of the Total Environment, 2021)
Rivers are significant sources of CO2 to the atmosphere, and karstic watersheds are particularly important in this respect due to their large availability of inorganic carbon. This study examines characteristics of dissolved inorganic carbon (DIC) and excess partial pressures of CO2 (epCO2) in the source springs and headwaters of four watersheds in a Central European karstic region, via dissolved inorganic carbon concentration and stable carbon isotope measurements. Our results show the most 13C-depleted δ13CDIC values at the source springs, which become rapidly enriched downstream due to CO2 degassing. Concurrently, epCO2 values, while consistently in excess of atmospheric concentrations at the spring sources, show decreases of up to 92% within only 50 m downstream distance. In conjunction with the large observed flux estimates of up to 88 g C m−2 day−1, these findings suggest that karstic springs are major CO2 sources to the atmosphere. Because headwater streams constitute the bulk of the surface area of most watersheds, they may provide a disproportionately large contribution to CO2 effluxes in carbonate-dominated basins, in which source springs play a particularly important role.
CRIS-Team Scopus Importer:2021-04-09
Keywords: Aquatic geochemistry; Carbon cycle; Carbon dioxide; Hydrogeology; Rivers; Stable isotopes

Extreme intensity of fluid-rock interaction during extensive intraplate volcanism - Beier, Christoph; Bach, Wolfgang; Busch, Alexander V.; Genske, Felix S.; Hübscher, Christian; Krumm, Stefan (Geochimica Et Cosmochimica Acta, 2019)
The initial formation and temporal evolution of large igneous plateaus and the extent to which these large enigmatic igneous features impact on their immediate and distant ecological surrounding remains a matter of active research. The compositional variability in large igneous provinces has mainly been attributed to changes in the melting regime and shallow crustal processes and commonly ranges from depleted tholeiitic basaltic to enriched alkaline lavas. Large igneous provinces erupted in the submarine environment however, may also experience intense hydrothermal alteration during their formation resulting from an increased exchange between seawater and the erupting lavas during their eruptive history. The submarine Azores Plateau in the Central Northern Atlantic has generally been treated to represent such large igneous province formed since ∼10 Ma by widespread volcanism and the unique tectonic regime which results in large fault systems exposing the erupted lavas. Here, we present new seismic, petrological and major element, trace element and isotope geochemical data from a ∼1000 m stratigraphic section of submarine lavas exposed at the western Princessa Alice bank. The 22 samples recovered from the near-vertical rift wall provide evidence for intense water-rock exchange not observed anywhere in oceanic crust sampled to date. Fluid-immobile incompatible trace elements show that the samples formed from higher degrees of partial melting of a mantle source that is less enriched than the source that gives rise to the islands today. The extents of melting today are very small, implying a change in melting regime since initial formation of the Princessa Alice Plateau basalts that correspond to a melting anomaly in the Azores. Our observations indicate that the extreme levels of alteration may result from a combination of intensified magmatic activity during initial formation of the Azores Plateau and the tectonic regime providing pathways for the fluids. Our results impact on the interpretation of shallow level crustal magmatic processes, in which the contribution of crustal sources to the ascending melt may be different to what had previously been suggested. We propose that hydrothermal alteration during submarine igneous plateau forming events can drastically change the compositions of the igneous crust. The associated elemental and isotopic exchange between the oceanic crust and hydrosphere may substantially change the chemical fluxes between oceans and crust during the emplacement of oceanic plateaus.
CRIS-Team Scopus Importer:2019-05-21
Keywords: Azores Plateau; Large igneous province; Ocean-crust exchange; Water-rock reactions

Extreme reefs: Analyses of modern bryostromatolite ("bryolith") reefs from marginal environments in the Netherlands with comparisons to ancient analogues - Harrison, G. William M.; Claußen, Anna Lene; Schulbert, Christian; Munnecke, Axel (EGU General Assembly Conference Abstracts, 2020)

Fabric transitions from shell accumulations to reefs: an introduction with Palaeozoic examples - Álvaro, José-Javier; Aretz, Markus; Boulvain, Frédéric; Munnecke, Axel; Vachard, Daniel; Vennin, Emmanuelle (Geological Society, London, Special Publication, 2007)
<p id="p-2" style="-webkit-font-smoothing: antialiased; margin: 0px 0px 15px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; font-variant-numeric: inherit; font-stretch: inherit; font-size: 14px; line-height: inherit; font-family: Verdana, Helvetica, Arial, sans-serif; word-wrap: break-word; color: rgb(0, 0, 0);"> One unresolved conceptual problem in some Palaeozoic sedimentary strata is the boundary between the concepts of ‘shell concentration’ and ‘reef’. In fact, numerous bioclastic strata are transitional coquina-reef deposits, because either distinct frame-building skeletons are not commonly preserved in growth position, or skeletal remains are episodically encrusted by ‘stabilizer’ (reef-like) organisms, such as calcareous and problematic algae, encrusting microbes, bryozoans, foraminifers and sponges. The term ‘parabiostrome’, coined by Kershaw, can be used to describe some stratiform bioclastic deposits formed through the growth and destruction, by fair-weather wave and storm wave action, of meadows and carpets bearing frame-building (archaeocyaths, bryozoans, corals, stromatoporoids, etc.) and/or epibenthic, non-frame-building (e.g. pelmatozoan echinoderms, spiculate sponges and many brachiopods) organisms. <p id="p-3" style="-webkit-font-smoothing: antialiased; margin: 0px 0px 15px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; font-variant-numeric: inherit; font-stretch: inherit; font-size: 14px; line-height: inherit; font-family: Verdana, Helvetica, Arial, sans-serif; word-wrap: break-word; color: rgb(0, 0, 0);"> This paper documents six Palaeozoic examples of stabilized coquinas leading to (pseudo)reef frameworks. Some of them formed by storm processes (generating reef soles, aborted reefs or being part of mounds) on ramps and shelves and were consolidated by either encrusting organisms or early diagenesic processes, whereas others, bioclastic-dominated shoals in barrier shelves, were episodically stabilized by encrusting organisms, indicating distinct episodes in which shoals ceased their lateral migration.
Keywords: Palaeozoic; stratigraphy; Fabrics; Fabric transitions; shell accumulations; Reefs

Facies and fauna of the Pennsylvanian Buckhorn Asphalt Quarry deposit: a review and new data on an important Palaeozoic fossil Lagerstätte with aragonite preservation - Seuß, Barbara; Nützel, Alexander; Mapes, Royal H.; Yancey, Thomas E. (Facies, 2009)
The Pennsylvanian Buckhorn Asphalt Quarry contains the best-preserved Palaeozoic mollusc fauna in the world. Early impregnation of mixed siliciclastic-carbonate rocks (mudstones, pack to grainstones, shell beds, and conglomerates) with hydrocarbons prevented aragonite destruction ("Impregnation Fossil Lagerstätte"). The exceptional preservation comprises shell microstructures, microornaments and early ontogenetic shells. Most gastropods had planktotrophic larval development indicating a high primary production although the remains of phytoplankton are very rare in this and other Late Palaeozoic deposits. Deposition occurred close to a shallow-water coastal area. Mass flow processes (density currents) triggered by storms were involved in the transport mechanisms of some units. Shells of benthic molluscs yield the most diverse known Palaeozoic microboring assemblage, indicating at least partly euphotic conditions. The invertebrate fauna comprises about 160 species and is dominated by molluscs, which is unusual for a Palaeozoic deposit, suggesting that aragonite dissolution produces a major bias in the fossil record. However, most mollusc genera in the Buckhorn deposit are also known from other Pennsylvanian occurrences as recrystallised shells. This shows that preservation bias via preferential aragonite dissolution may be overestimated. © Springer-Verlag 2009.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.LP.facies
Keywords: "Impregnation Fossil Lagerstätte"; Aragonite preservation; Buckhorn Asphalt; Facies; Oil migration; Pennsylvanian

Facies and fauna of Triassic to Early Jurassic deposits from the Hochfelln Massif (Northern Calcareous Alps, Bavaria) - Seuß, Barbara; Nützel, Alexander; Höfling, Richard; Schulbert, Christian (System Earth - Biosphere Coupling, 2005)
A suite of Early Mesozoic (Late Triassic, Norian to Early Jurassic) calcareous beds was studied from the Hochfelln Massif in the Northern Calcareous Alps (Bavaria, South Germany). The main part of the Hochfelln Mountain is built up by the Hauptdolomit Group consisting of thick peritidal deposits and overlain by basin deposits of the Rhaetian Kössen Formation and Rhaetian reefoidal limestone with corals. Unlike many other sections in the Tethys realm, coral growth seems to continue into the Jurassic or starts again relatively early within the Early Jurassic. Silicified corals and other marine invertebrates are present in the calcareous, micritic Hochfelln Beds. A reexamination of previously collected ammonite material indicates the presence of Coroniceras sp. which suggests an Early Sinemurian age for the Hochfelln Beds (= Hochfellnkalk). Abundant sponge spicules (spiculites) suggest that sponges were the source for the silicification. The historical gastropod collection (Bayerische Staatssammlung für Paläontologie (BSP), Munich) from the Hochfelln Mountain was reexamined and new material was collected. The Hochfelln gastropod fauna yields a total of 28 species. It represents one of the richest Early Jurassic gastropod faunas of Germany and the Northern Calcareous Alps. The generic assignments of several species were changed and twelve species were newly reported some of which are undescribed. The relatively diverse Early Sinemurian gastropod fauna together with the coral growth on top of the Hochfelln Mountain indicate rapid recovery from the end-Triassic biotic crisi

Facies architecture of the Etjo Sandstone Formation and its interaction with the Basal Etendeka Flood Basalts of northwest Namibia: implications for offshore prospectivity. - Jerram, Dougal A.; Mountney, Nigel; Stollhofen, Harald (The oil and gas habitats of the South Atlantic, 1999)
The Basal Etendeka Flood Basalt stratigraphy in the Huab Basin of northwest Namibia comprises a series of lava flows interleaved with aeolian sandstone bodies of the Etjo Sandstone Formation. The sandstone units are characterized by three main types: (1) the major erg - a mixed aeolian and fluvial facies up to 150 m thick; (2) minor ergs - aeolian facies which occur directly above the first volcanic units and are up to 60 m thick; (3) isolated bodies-multidune, single dune and lava topography infills. A variety of bypass surfaces identified by sand-filled cracks and sediment-lava breccias occur on lava top surfaces. Preserved ripples and pahoehoe lava imprints indicate that the aelian sand dunes were actively migrating during basalt emplacement. Observations recorded in the Basal Etendeka Flood Basalts which may be of relevance to offshore hydrocarbon exploration include: a major-minor erg relationship resulting in large sandbodies up to 60 m thick which occur directly after the first volcanic units; the occurrence of sand-filled fissures up to 36 m in depth which would greatly influence connectivity in an offshore setting; the identification of bypass surfaces as marker horizons which may laterally correlate with isolated sandbodies.
UnivIS-Import:2015-04-20:Pub.1999.nat.dgeo.IGM.LG.facies

Facies architecture variations and seismogenic structures in the Carboniferous-Permian Saar-Nahe Basin (SW Germany): Evidence for extension-related transfer fault activity. - Stollhofen, Harald (Sedimentary Geology, 1998)
Sedimentary and volcanic strata in the late-orogenic intermontane Saar-Nahe Basin preserve a record of sedimentary responses to motion on contemporaneously active faults. Studies of such deposits can constrain both concepts for lateral and vertical sedimentary facies development and geometric and kinematic models of intrabasinal extension. During Carboniferous-Permian syn-rift development, the Saar-Nahe Basin underwent a marked intrabasinal segmentation generated by the offsets of longitudinal normal faults and dextral (oblique) strike-slip faults which were developed perpendicular to the SW-NE basin elongation. The latter are interpreted as transtensional transfer faults which compartmentalized the basin into segments of differing structural style, bed thickness and facies development. The fault zones themselves bound an asseblage of variously sized uplifted and downthrown blocks showing variable magnitudes and senses of displacement. Their activities are recorded by the contrasting depositional histories of tephrostratigraphically constrained sedimentary units occupying footwall and hanging wall block positions during basin filling. The influence of faults on the depositional system is seen in their effect as topographic barriers, thus rstricting free dispersal and mixing of sediment. Particular sedimentary facies, such as coals and biogenic limestones, are confined to the immediate vicinity of the fault zones, indicating the isolation of sediment-starved areas near downthrown hanging walls. Other fault-generated depressions acted as depositional traps favouring considerable accumulations of basaltic lavas, volcaniclastic mass flows and fluvial channel deposits. In contrast, uplifted footwalls are characterized by the formation of unconformities and pedogenic features. The abundance of syn-tectonic deformation structures such as sediment-filled fissures, intraformational breccias, series of micro-faults, clastic dykes and other water-escape features within syn-rift strata and their distinct spatial linkage to fault zones implies considerable seismically triggered processes associated with faulting. The combined occurrence of abrupt variations in facies architecture across faults and seismotectonic structures suggests that the basin subsidence history involved a series of events rather than gradual change.
UnivIS-Import:2015-03-05:Pub.1998.nat.dgeo.IGM.LG.facies

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

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