Spatial and temporal variations of pCO2, dissolved inorganic carbon, and stable isotopes along a temperate karstic watercourse - van Geldern, Robert; Schulte, Peter; Mader, Michael; Baier, Alfons; Barth, Johannes (Hydrological Processes, 2015)

Spatial distribution analysis of mass movements triggered by the 2005 Kashmir earthquake in the Northeast Himalayas of Pakistan - Basharat, Muhammad; Baig, Mirza Shahid; Khan, Muhammad Rustam; Rohn, Joachim (Geomorphology, 2014)
Keywords: 2005 Kashmir earthquake; Epicentre; Mass movement concentration; Reactivated Muzaffarabad Fault

Spatial distribution of rockslide deposits and their morphological features suggest timing and palaeo-environmental conditions for rock slope failures in innerdalen and innfjorddalen, møre og romsdal county, Western Norway - Schleier, Markus; Hermannsdörfer, Ralf; Rohn, Joachim (Italian Journal of Engineering Geology and Environment, 2013)
Keywords: Morphological analyses; Multiple landslide deposits; Palaeo-environmental conditions; Rock avalanche; Western norway

Spatially Heterogeneous Responses of Planktonic Foraminiferal Assemblages Over 700,000 Years of Climate Change - Mathes, Gregor H; Reddin, Carl James; Kießling, Wolfgang; Antell, Gawain S; Saupe, Erin E; Steinbauer, Manuel J (Global Ecology and Biogeography, 2024)
Aim: To determine the degree to which assemblages of planktonic foraminifera track thermal conditions. Location: The world's oceans. Time Period: The last 700,000 years of glacial–interglacial cycles. Major Taxa Studied: Planktonic foraminifera. Methods: We investigate assemblage dynamics in planktonic foraminifera in response to temperature changes using a global dataset of Quaternary planktonic foraminifera, together with a coupled Atmosphere–Ocean General Circulation Model (AOGCM) at 8000-year resolution. We use ‘thermal deviance’ to assess assemblage responses to climate change, defined as the difference between the temperature at a given location and the bio-indicated temperature (i.e., the abundance-weighted average of estimated temperature optima for the species present). Results: Assemblages generally tracked annual mean temperature changes through compositional turnover, but thermal deviances are evident under certain conditions. The coldest-adapted species persisted in polar regions during warming but were not joined by additional immigrants, resulting in minimal assemblage turnover. The warmest-adapted species persisted in equatorial regions during cooling with similarly minimal assemblage change. Assemblages at mid-latitudes mostly tracked temperature cooling and warming. Main Conclusions: Planktonic foraminiferal assemblages were generally able to track or endure temperature changes: as climate warmed or cooled, bio-indicated temperature also became warmer or cooler, although to a variable degree. At polar sites under warming and at equatorial sites under cooling, the change in bio-indicated temperature was less than, or even opposite to, what would be expected from estimated environmental change. Nevertheless, all studied species persisted across the study interval, regardless of thermal deviance—a result that highlights the resilience and inertia of planktonic foraminifera on an assemblage level to the last 700,000 years of climate change.
CRIS-Team Scopus Importer:2024-08-30
Keywords: climate change ecology; conservation palaeobiology; glacial–interglacial cycles; plankton

Spatially referenced 3D-Characterisation of Fracture Networks - Drews, Michael; Deckert, Hagen; Gessner, Klaus; et al. (Conference Proceedings, 2007)

Spatially resolved quantitative in-situ phase analysis of a self-leveling compound - Seifert, Severin; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (Cement and Concrete Research, 2012)
The development of the crystalline microstructure of a hydrating self-leveling compound (SLC) was analyzed using a two-dimensional XRD (GADDS). The application of non-destructive micro-diffraction with the GADDS, combined with a custom-made sample holder, made it possible to carry out position-sensitive in-situ measurements of a Calcium-Aluminate-Cement-(CAC)- dominated SLC. Different substrates were used in the measurement procedures so as to acquire data regarding the influence of the properties of the ground surface on the process of hydration. The results show that the crystalline microstructure is strongly affected by the availability of free water. The strongly vertically-fluctuating water-content of the hydrating mortar, which is mainly influenced by outside conditions, has a very significant effect upon the resulting ettringite content. This fact is also reflected in the resulting microstructure of the cured SLC. © 2012 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-04-14:Pub.2012.nat.dgeo.IGM.LM.spatia
Keywords: Calcium Aluminate Cement (D); Hydration (A); Microstructure (B); Mortar (E); X-ray diffraction (B)

Spatial-temporal analysis of precipitation characteristics in Artvin, Turkey - Aydin, Olgu; Raja, Nussaïbah Begum (Theoretical and Applied Climatology, 2020)
The region of Artvin, located in the northeast of Turkey, usually experiences high-intensity precipitation events that occur within a short-time period. Along with other environmental impacts, these events also lead to flash floods in this region. The purpose of this study was to evaluate the changing spatial and temporal characteristics of precipitation on August 24, 2015 and November 11 to 12, 2015 that triggered flash floods and landslides in Artvin. We apply spatiotemporal (ST) kriging as a tool to investigate these ST patterns. The average hourly precipitation data were used, taking episodes of heavy rainfall into account. Our results show that precipitation reached the highest values of 30–50 mm between 8:00 and 9:00 pm in the Hopa district on August 24, 2015. On November 11, 2015, rainfall values reached ≥ 15 mm at 4:00 PM in the Borçka district. During both events occurred on November 12, 2015, it rained for 7 h continuously with precipitation values ranging between 5 and 10 mm. The duration of the precipitation lasted for 8 h. In addition, flood events also occurred in the districts of Arhavi and Murgul. This highlights that these districts are vulnerable in the Artvin region and paves the way for decision-makers to implement measures against flash floods in these at-risk districts. In conclusion, the analysis of spatiotemporal characteristics of heavy rainfall events represents an indispensable basis to ensure that necessary precautions regarding flash flood events in the city are take
Keywords: precipitation characteristics; flood events; space and time; kriging; artvin

Spatial variability of source composition and petrogenesis in rift and rift flank alkaline lavas from the Eger Rift, Central Europe - Haase, Karsten; Beier, Christoph; Regelous, Marcel; Rapprich, Vladislav; Renno, Axel (Chemical Geology, 2016)
Geochemical data on Oligocene melilititic and nephelinitic rocks from the northern Eger Rift flank in Central Europe reveal significant differences to nephelinites and basanites of volcanic complexes in the rift axis. The mafic rift flank lavas are more enriched in TiO, PO and CaO but have lower SiO compared to the alkaline volcanic rocks in the Eger Rift. The differences in major element compositions imply (1) lower degrees of partial melting beneath the rift flank than beneath the rift axis evident from lower SiO and higher (Ce/Yb) ratios in the off-axis basalts and (2) different assemblages of fractional crystallization. The mafic rift flank magmas experienced crystal fractionation of olivine followed by clinopyroxene fractionation in contrast to early simultaneous olivine and clinopyroxene fractionation in the magmas below the rift basin. In addition, assimilation of continental crustal rocks is associated with crystal fractionation and changes the composition of the lavas. The rift axis lavas are enriched in Nb and Ba relative to La and have higher Sr and lower Nd isotope ratios than the rift flank magmas indicating different mantle sources. The melting zones beneath the rift axis and the rift flank region are separated although they are only some 20km apart and no melt exchange between the magma systems is observed. All magmas probably experienced mixing between a deep carbonatitic and a shallower low-degree silicate melt.
Keywords: Continental rifting; Crustal assimilation; Fractional crystallization; Intraplate volcanism; Magma formation

Spatial Variations in Magmatic Volatile Influx and Fluid Boiling in the Submarine Hydrothermal Systems of Niuatahi Caldera, Tonga Rear-Arc - Falkenberg, Jan; Keith, Manuel; Haase, Karsten; Sporer, Christian; Bach, Wolfgang; Klemd, Reiner; Strauss, Harald; Storch, Bettina; Peters, Christian; Rubin, Kenneth H.; Anderson, Melissa O. (Geochemistry Geophysics Geosystems, 2022)
Submarine caldera volcanoes may host several hydrothermal systems along the caldera wall and related to volcanic cones. Fluid boiling and magmatic volatile influx are common processes in shallow (<2,000 mbsl) subduction zone-related environments causing variations in the mineralogical and chemical composition of seafloor hydrothermal mineralizations that remain poorly constrained. The submarine caldera of Niuatahi volcano, Tonga rear-arc, hosts four active vent sites discharging high temperature fluids (<334 degrees C) with variable salinities (369-583 mM Cl) that are indicative of fluid boiling, recorded by distinct Te/As and Te/Au in pyrite, sphalerite, and chalcopyrite. High sulfidation mineral assemblages (e.g., enargite), stable S isotope data and similar trace element signatures in sulfides and native S condensates suggest a minor and/or infrequent contribution of magmatic SO2 to the hydrothermal systems located proximal to the caldera center causing a volatile element (e.g., Se, Bi, Te) enrichment. The hydrothermal system at the northern caldera wall is decoupled from the magmatic SO2 source, as revealed by radiogenic Pb isotopes. Instead, S isotope and trace element constraints propose a host rock-dominated hydrothermal system, lacking a magmatic volatile influx. The observed hydrothermal fractionation processes (fluid boiling) and the distinct metal (loid) sources (magmatic volatiles vs. host rock) represent a continuum from magmatic volatile- to host rock-dominated hydrothermal systems within the Niuatahi caldera. This leads to seafloor mineralizations with spatially selective trace element enrichments, like Te, Se, and Bi (+/- Au, Ag) in the caldera center compared to Au, Ag, Zn, Cd, and Pb at the northern caldera wall.
CRIS-Team WoS Importer:2022-04-29

Species–area relationships in continuous vegetation: Evidence from Palaearctic grasslands - Dengler, Jürgen; Matthews, Thomas J.; Steinbauer, Manuel; Wolfrum, Sebastian; Boch, Steffen; Chiarucci, Alessandro; Conradi, Timo; Dembicz, Iwona; Marcenò, Corrado; García-Mijangos, Itziar; Nowak, Arkadiusz; Storch, David; et al. (Journal of Biogeography, 2019)
Aim: Species–area relationships (SARs) are fundamental scaling laws in ecology although their shape is still disputed. At larger areas, power laws best represent SARs. Yet, it remains unclear whether SARs follow other shapes at finer spatial grains in continuous vegetation. We asked which function describes SARs best at small grains and explored how sampling methodology or the environment influence SAR shape. Location: Palaearctic grasslands and other non-forested habitats. Taxa: Vascular plants, bryophytes and lichens. Methods: We used the GrassPlot database, containing standardized vegetation-plot data from vascular plants, bryophytes and lichens spanning a wide range of grassland types throughout the Palaearctic and including 2,057 nested-plot series with at least seven grain sizes ranging from 1 cm2 to 1,024 m2. Using nonlinear regression, we assessed the appropriateness of different SAR functions (power, power quadratic, power breakpoint, logarithmic, Michaelis–Menten). Based on AICc, we tested whether the ranking of functions differed among taxonomic groups, methodological settings, biomes or vegetation types. Results: The power function was the most suitable function across the studied taxonomic groups. The superiority of this function increased from lichens to bryophytes to vascular plants to all three taxonomic groups together. The sampling method was highly influential as rooted presence sampling decreased the performance of the power function. By contrast, biome and vegetation type had practically no influence on the superiority of the power law. Main conclusions: We conclude that SARs of sessile organisms at smaller spatial grains are best approximated by a power function. This coincides with several other comprehensive studies of SARs at different grain sizes and for different taxa, thus supporting the general appropriateness of the power function for modelling species diversity over a wide range of grain sizes. The poor performance of the Michaelis–Menten function demonstrates that richness within plant communities generally does not approach any saturation, thus calling into question the concept of minimal area.
CRIS-Team Scopus Importer:2019-11-01
Keywords: logarithmic function; Michaelis–Menten function; minimal area; nested-plot sampling; nonlinear regression; Palaearctic grassland; plant biodiversity; power law; scaling law; species–area relationship (SAR)

Speicherminerale mit Ellestadit, Nasonit, Ganomalit und Silicocarnotit Struktur - Pöllmann, Herbert; Stemmermann, Peter; Neubauer, Jürgen (European Journal of Mineralogy, 1991)
UnivIS-Import:2015-03-05:Pub.1991.nat.dgeo.IGM.LM.speich

Sponge-microbial build-ups from the lowermost Triassic Chanakhchi section in southern Armenia: Microfacies and stable carbon isotopes - Friesenbichler, Evelyn; Richoz, Sylvain; Baud, Aymon; Krystyn, Leopold; Sahakyan, Lilit; Vardanyan, Sargis; Peckmann, Joern; Reitner, Joachim; Heindel, Katrin (Palaeogeography, Palaeoclimatology, Palaeoecology, 2018)

Sponge Takeover from End-Permian Mass Extinction to Early Induan Time: Records in Central Iran Microbial Buildups - Baud, Aymon; Richoz, Sylvain; Brandner, Rainer; Krystyn, Leopold; Heindel, Katrin; Mohtat, Tayebeh; Mohtat-Aghai, Parvin; Horacek, Micha (Frontiers in Earth Science, 2021)
The end-Permian mass extinction was the most severe biotic crisis in Earth’s history. In its direct aftermath, microbial communities were abundant on shallow-marine shelves around the Tethys. They colonized the space left vacant after the dramatic decline of skeletal metazoans. The presence of sponges and sponge microbial bioherms has largely gone unnoticed due to the sponges’ size and the cryptic method of preservation. In addition to sponge dominated facies recently described in South Armenia and Northwestern Iran, we describe here sponge-microbial bioherms cropping out in two well-known Permian-Triassic boundary localities: the Kuh-e Hambast section, south-east of Abadeh city and the more distal Shahreza section, near Isfahan. In both sections, the extinction horizon is located at the top of an upper Changhsingian ammonoid-rich nodular limestone, called Paratirolites limestone. At Kuh-e Hambast, the overlying decimetric thick shale deposit called “boundary clay,” the latest Permian in age, is conformably overlain by well-dated transgressive basal Triassic platy limestone containing four successive levels of decimeter to meter scale, elongated to form cup-shaped mounds made of branching columnar stromatolites. Sponge fibers from possibly keratose demosponge, are widely present in the lime mudstone matrix. At the Shahreza section, above the extinction level, the boundary clay is much thicker (3 m), with thin platy limestone intervals, and contains two main levels of decimeter to meter scale mounds of digitate microbialite crossing the Permian-Triassic boundary with similar sponge fibers. Three levels rich in thrombolite domes can be seen in the overlying 20 m platy limestone of earliest Triassic age. Sponge fibers and rare spicules are present in their micritic matrix. These sponge fibers and spicules which are abundant in the latest Permian post-extinction boundary clay, followed microbial buildups during the Griesbachian time.
CRIS-Team Scopus Importer:2021-06-18
Keywords: carbonate mounds; end-permian mass extinction; Induan; keratose demosponge; metazoan bioherms

Spumispongia merklei nov. sp. (Porifera) from the Upper Jurassic (South Germany, Swabian Alb, Blautal) - Senowbari-Daryan, Baba; Koch, Roman (Geologische Blätter für Nordost-Bayern und angrenzende Gebiete, 2012)
UnivIS-Import:2017-11-07:Pub.2012.nat.dgeo.IGM.LP.spumis

Spurenlesen in der Vergangenheit - die Burghöhle Wolfsegg als Treffpunkt für Mensch, Höhlenlöwe und Co. - Hilpert, Brigitte (Mitteilungen - Verbandes der Deutschen Hohlen- und Karstforscher, 2023)

Sr/Ca and Ba/Ca ratios support trophic partitioning within a Silurian conodont community from Gotland, Sweden - Terrill, David F.; Jarochowska, Emilia; Henderson, Charles M.; Shirley, Bryan; Bremer, Oskar (Paleobiology, 2022)
Conodonts were a highly diverse and abundant vertebrate group whose fossils are found in marine Paleozoic and Triassic strata around the world. They inhabited environments ranging from lagoons to open oceans and are represented by a wide variety of dental morphologies. Conodonts may have filled many different ecological niches and represent a significant proportion of nekton before the Devonian. Despite this, very little is known about trophic ecology of conodonts. While morphological diversity suggests a complex trophic structure within conodont communities, there is little evidence to support dietary niche partitioning among conodonts. We tested the hypothesis that individual conodont taxa occupied different trophic niches, using Sr/Ca and Ba/Ca ratios preserved in the dental elements of assemblages from Silurian strata of Gotland, Sweden. Sr/Ca and Ba/Ca have been shown to vary in vertebrate skeletal tissues depending on trophic positioning, although biological and environmental conditions can affect these ratios. Environmental influences were minimized by examining entire conodont communities from a tropical epeiric sea and by measuring strontium isotope ratios using thermal ionization mass spectrometry in the most metropolitan taxon (Ozarkodina confluens). Composition of white matter, a tissue unique to conodonts, was also analyzed using microprobe analysis, revealing significantly lower Sr concentrations than in surrounding lamellar tissue, suggesting taxon-specific histology should be considered when analyzing conodonts for geochemical data. Excluding taxa with highly variable quantities of white matter, the results show that each taxon preserves different Sr/Ca and Ba/Ca ratios with limited overlap, indicating variation in trophic positioning.
CRIS-Team Scopus Importer:2022-04-29

Sr/Ca ratios and oxygen isotopes from sclerosponges: Temperature history of the Caribbean mixed layer and thermocline during the Little Ice Age - Haase, Alexandra; Böhm, Florian; Eisenhauer, Anton; Dullo, Wolf-Christian; Joachimski, Michael; Hansen, Bent; Reitner, Joachim; Schramm, Alexandra (Paleoceanography, 2003)
We investigate aragonitic skeletons of the Caribbean sclerosponge Ceratoporella nicholsoni from Jamaica, 20 m below sea level (mbsl), and Pedro Bank, 125 mbsl. We use SO and Sr/Ca ratios as temperature proxies to reconstruct the Caribbean mixed layer and thermocline temperature history since 1400 A.D. with a decadal time resolution. Our age models are based on U/Th dating and locating of the radiocarbon bomb spike. The modern temperature difference between the two sites is used to tentatively calibrate the C. nicholsoni Sr/Ca thermometer. The resulting calibration points to a temperature sensitivity of Sr/Ca in C. nicholsoni aragonite of about -0.1 mmol/mol/K. Our Sr/Ca records reveal a pronounced warning from the early 19th to the late 20th century, both at 20 and 125 mbsl. Two temperature minima in the shallow water records during the late 17th and early 19th century correspond to the Maunder and Dalton sunspot minima, respectively. Another major cooling occurred in the late 16th century and is not correlatable with a sunspot minimum. The temperature contrast between the two sites decreased from the 14th century to a minimum in the late 17th century and subsequently increased to modern values in the early 19th century. This is interpreted as a long-term deepening and subsequent shoaling of the Caribbean thermocline. The major trends of the Sr/Ca records are reproduced in both specimens but hardly reflected in the SO records.
Keywords: Caribbean Sea; Little Ice Age; Oxygen isotopes; Sclerosponges; Sr/Ca; Temperature; Thermocline

Stability conditions and compositional variations of deerite in high-pressure meta-ironstone during subduction–exhumation processes (SW Tianshan, China) - Li, Ji Lei; Klemd, Reiner; Höfer, Heidi E.; Gao, Jun (Lithos, 2021)
Index minerals in metamorphic rocks, such as coesite, glaucophane, or lawsonite, are of great importance to understand high-pressure (HP) to ultrahigh-pressure (UHP) metamorphism, the thermal gradient, and the geodynamics of subduction zones. Deerite is thought to be diagnostic for blueschist-facies metamorphism in cold subduction environments and a sensitive indicator of the oxygen fugacity (fO2) in Fe-rich rocks. However, little is known concerning its stability and compositional variation during subduction and exhumation cycles. In this study, we provide the first detailed investigation of deerite in eclogite-facies meta‑ironstones (deerite–garnet riebeckitite) from the Southwestern Tianshan (U)HP metamorphic belt. Petrological observation and textural evidence suggest that the meta‑ironstones –enclosing eclogite blocks– form part of an initially coherent volcano-sedimentary sequence that underwent a common tectono-metamorphic evolution, including HP metamorphism and subsequent exhumation. Two types of deerite, which display a different texture (inclusion vs. matrix) and composition (TiO2 content), occur in the deerite–garnet riebeckitite. Dee_1 and aegirine–augite appear exclusively as fine-grained inclusions in garnet, and together with garnet, riebeckite, quartz and magnetite form the peak metamorphic mineral assemblages at P–T conditions of 510 °C and 2.6 GPa. Matrix deerite (Dee_2), on the other hand, mainly occurs as coarse-grained rods and acicular needle-like grains in quartz, and rarely as inclusions in riebeckite and garnet intimately in the riebeckitite, representing the blueschist-facies retrogression of the meta‑ironstones during exhumation. The garnet–clinopyroxene oxybarometer and thermodynamic calculations show that the fO2 of the deerite–garnet riebeckitite increases from ΔFMQ–0.64 at the peak eclogite-facies stage to ΔFMQ+1.5 at the blueschist-facies retrogression. This fO2 variation corresponds to the chemical variation of deerite, whereby the TiO2 content increases gradually from <0.1 wt% in the Dee_1 in garnet to about 5 wt% in the matrix Dee_2. Our study reveals the detailed metamorphic P–T–fO2 evolution of the prograde eclogite- and retrograde blueschist-facies deerite-bearing meta‑ironstones during subduction–exhumation processes. This study further emphasizes the potential of deerite to reveal the P–T–fO2 evolution of subduction-related high-pressure rocks.
CRIS-Team Scopus Importer:2021-06-11
Keywords: Deerite; Eclogite; Oxygen fugacity; P–T evolution; Subduction zone; Tianshan

Stable and radiogenic isotope analyses on shark teeth from the Early to Middle Permian (SakmarianRoadian) of the southwestern USA - Fischer, Jan; Schneider, Joerg W.; Hodnett, John-Paul M.; Elliott, David K.; Johnson, Gary D.; Voigt, Silke; Joachimski, Michael; Tichomirowa, Marion; Goetze, Jens (Historical Biology, 2014)
δ18OPvalues and87Sr/86Sr ratios were determined on disarticulated xenacanthiform, hybodontid and ctenacanthid shark tooth material from several Early Permian (Sakmarian–Kungurian) continental bone beds of northern Texas and southern Oklahoma as well as from the marine Middle Permian (Roadian) of northern Arizona. The δ18OPvalues derived from the teeth of bone beds are in the range of 17.6–23.5‰ VSMOW, and are mostly depleted in18O by 0.5–5‰ relative to proposed coeval marine δ18OPvalues. This indicates an adaptation to freshwater habitats on the Early Permian coastal plain by several sharks. Distinctly higher δ18OPvalues from two bone beds are attributed to significant evaporative enrichment in18O in flood plain ponds.87Sr/86Sr ratios of around 0.71077 are notably more radiogenic than87Sr/86Sr of contemporaneous seawater. In contrast, the isotopic composition of teeth from the marine Kaibab Formation is characterised by low δ18OPvalues in the range of 13.4–15.6‰ VSMOW while87Sr/86Sr ratios of around 0.70821 are closer to the Roadian seawater value. The distinctly depleted δ18OPvalues cannot be readily explained by fluvially affected freshening in a nearshore marine environment, so a diagenetic alteration of the Kaibab material seems to be more likely, excluding it from further interpretation.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LG.stable
Keywords: bioapatite; bone beds; Early–Middle Permian; freshwater shark; Kaibab Formation; oxygen isotopes; strontium isotopes

Stable carbon and oxygen equilibrium isotope fractionation of supercritical and subcritical CO2 with DIC and H2O in saline reservoir fluids - Becker, Veith; Myrttinen, Anssi; Nightingale, Michael; Shevalier, Maurice; Rock, Luc; Mayer, Bernhard; Barth, Johannes (International Journal of Greenhouse Gas Control, 2015)

Stable carbon and oxygen isotope geochemistry as provenance indicator for the picture stones on Gotland (Sweden) - Hänsel, Patrick; Oehrl, Sigmund; Ideström, Lena; Widerström, Per; Reddin, Carl James; Munnecke, Axel (GFF, 2023)
The picture stones from Gotland are one of the most famous and exceptional groups of monuments known from Swedish Prehistory. These carved memorial stones and their extraordinarily rich imagery are a unique source for the study of Late Iron and Viking Age culture and in particular Scandinavian pre-Christian religions. The Gotlandic picture stones are mainly made from the thickly layered limestones surrounding the reefs and bioherms of Gotland’s carbonate platform from the middle part of the Silurian (latest Llandovery to Ludlow, Telychian–Ludfordian). However, the exact origins of the picture stones’ raw materials on Gotland have remained undetermined. In this paper, we investigate the geological origin of the raw material by isotope geochemistry. Whereas the oxygen (δ18O) and strontium isotope ratio (87Sr/86Sr) were strongly altered by diagenesis the carbon isotope ratio (δ13C) is quite stable. Because the different geological units on Gotland show specific isotope signatures, the δ13C values from picture stones can be used to assign them to the respective geological unit, and thus to the source area of the raw material. This also allows for an estimation of transport distance minima between the raw material source area and the find place of each sampled picture stone. Most of the picture stones seem to be produced from local material with short transport distances, less than 10 km and only a few were transported at a far distance exceeding 10 km. In summary, the transport distance was dependent mostly on the local availability of picture-stone-suitable rocks.
CRIS-Team Scopus Importer:2023-12-01
Keywords: Carbon isotopes; Gotland; Iron Age; oxygen isotopes; picture stones; strontium isotopes; transport distances

Stable carbon isotope analysis of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in natural waters - Results from a worldwide proficiency test - van Geldern, Robert; Verma, Mahendra P.; Carvalho, Matheus C.; Grassa, Fausto; Delgado-Huertas, Antonio; Monvoisin, Gael; Barth, Johannes (Rapid Communications in Mass Spectrometry, 2013)

Stable carbon isotope development and sea-level changes during the Late Ludlow (Silurian) of the Łysogóry region (Rzepin section, Holy Cross Mountains, Poland) - Kozłowski, Wojciech; Munnecke, Axel (Facies, 2010)
The Ludlow deposits of the Winnica Formation in the Rzepin section (Holy Cross Mountains, Poland) have been studied with respect to their facies evolution and stable carbon isotope ratios from whole-rock samples. The C-isotope curve of the Rzepin section records a distinct positive excursion with maximal values of +8.9‰. A Late Ludlow positive isotope excursion is known from different paleocontinents and thus is regarded as a global isotope event. The presence of the event allows for a chemostratigraphic correlation of the Rzepin profile with the classical, biostratigraphically well-dated Gotland section. The Ludlow deposits of the Holy Cross Mountains are interpreted in terms of sea-level changes during the isotope excursion. Because the Rzepin and Gotland sections are positioned on the opposite sides of the same foreland basin, a comparison of their sequence stratigraphy allows to test the regularities of the sea-level changes on the shelf of Baltica. In the present paper, a modified view of the recently published sequence stratigraphy of the Gotland succession is presented. Our results indicate that the positive Ludlow δC excursion is connected with prolonged low-stand conditions with small, internal transgressive pulses. © 2010 Springer-Verla
Keywords: C-isotope excursion; Gotland; Holy Cross Mountains; Ludlow; Poland; Sea-level changes; Upper Silurian

Stable carbon isotope fractionation data between H2CO 3 * and CO2(g) extended to 120 °c - Myrttinen, Anssi; Becker, Veith; Mayer, B.; Barth, Johannes (Rapid Communications in Mass Spectrometry, 2014)

Stable carbon isotope stratigraphy in the Ordovician of South China - Munnecke, Axel; Zhang, Yuandong; Xiao, Liu; Cheng, Junfeng (Palaeogeography, Palaeoclimatology, Palaeoecology, 2011)
About 500 samples from 11 Ordovician sections in South China have been analysed for their δC composition. Four sections are located in the Yangtze platform region, the remaining seven sections in the Jiangnan slope region. The sections span more or less the entire Ordovician, but the sample resolution in its lower part (Tremadocian to Dapingian) is lower than in its upper part (Darriwilian to Hirnantian). Overall, the data show a good correlation with the published global isotope curve. At the Cambrian-Ordovician boundary positive values are observed. In the succeeding Tremadocian the values decrease and remain negative into the early Floian. In the late Floian, the values increase to slightly positive. The correlation of Dapingian rocks between the Yangtze and the Jiangnan regions is somewhat problematic which might be due to high siliciclastic input in the Yangtze section. In the Darriwilian a small positive excursion is observed in the Yangtze platform area, however, it is missing in the Jiangnan slope area. This excursion probably correlates with the mid-Darriwilian excursion (MDICE) reported from Baltoscandia. Both chemostratigraphy and conodont biostratigraphy indicate a possible gap between the Shihtzupu Formation and the Pagoda Formation, i.e. most of the Sandbian is probably not represented in the Upper Yangtze region. The earliest Katian is characterised by a pronounced positive excursion correlating with the well-known global Guttenberg excursion (GICE). In the late Katian at least one additional positive excursion was determined. The precise biostratigraphy, however, is not clear, and therefore it is not known which of the known four to five remaining Katian δC excursions identified in Baltica correlate(s) with the one(s) observed in the present study, and further biostratigraphic study is required. The lower part of the Hirnantian excursion (HICE) is probably not preserved, with only small remnants of the HICE observed near the base of the Kuanyinchiao Bed. © 2011 Elsevier B.
Keywords: Graptolites; Ordovician; South China; Stable carbon isotopes; Stratigraphy

Stable carbon isotope techniques to quantify CO 2 trapping under pre-equilibrium conditions and elevated pressures and temperatures - Myrttinen, Anssi; Jeandel, E.; Ukelis, O.; Becker, Veith; van Geldern, Robert; Blum, Philipp; Barth, Johannes (Chemical Geology, 2012)

Stable isotope and dissolved inorganic carbon sampling, monitoring and analytical methods in CO2 injection and EGR projects - Myrttinen, Anssi; Becker, Veith; van Geldern, Robert; Barth, Johannes; Nowak, Martin (Underground Storage of CO2 and Energy, 2010)

Stable isotope and ostracode species assemblage evidence for lake level changes of Nam Co, southern Tibet, during the past 600 years - Wrozyna, Claudia; Frenzel, Peter; Steeb, Philip; Zhu, Liping; van Geldern, Robert; Mackensen, Andreas; Schwalb, Antje (Quaternary international, 2010)

Stable isotope and trace element geochemistry of Upper Cretaceous carbonates and belemnite rostra (Middle Campanian, north Germany) - NIebuhr, Sara; Joachimski, Michael (Geobios, 2002)
Trace element contents and stable isotopic composition of Middle Campanian marl-limestone rhythmites and belemnite rostra of Belemnitella mucronata were investigated. High strontium and low iron as well as manganese and magnesium contents of belemnite calcite and bulk rock samples suggest no diagenetic overprint. However, the orange-coloured cathodoluminescence of coccolith-rich sediments indicates diagenetic cementation and/or recrystallization. The non-luminescent belemnite rostra reveal an extraordinary preservation of the microstructures that is interpreted to have been favoured by a silification of the outer rim of the belemnite rostra. Carbon isotope ratios of the coccolith limestones and belemnite rostra are comparable, with higher δC variations observed for belemnite calcite. The 1.5-2‰ depletion in δO of the marl-limestone rhythmites relative to belemnite calcite is explained by diagenetic alteration of the sediments. Palaeotemperatures, calculated from the δO values of the well-preserved belemnite rostra, are around 12.5 ± 2 °C and suggest rather low sea-surface temperatures for the Middle Campanian epicontinental sea of north Germany assuming a water depth of less than 100 m. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.
Keywords: Belemnites; Carbon and oxygen isotopes; Carbonate diagenesis; North Germany; Palaeotemperatures; Upper Cretaceous

Stable isotope and trace element geochemistry of Upper Cretaceous coccolith limestones and belemnite rostra (Middle Campanian, North Germany) - Joachimski, Michael; et al. (Geobios, 2002)
UnivIS-Import:2015-03-09:Pub.2002.nat.dgeo.IGM.LG.stable

Stable isotope geochemistry of pore waters and marine sediments from the New Jersey shelf: Methane formation and fluid origin - van Geldern, Robert; Hayashi, Takeshi; Boettcher, Michael E.; Mottl, Michael J.; Barth, Johannes; Stadler, Susanne (Geosphere, 2013)

Stable isotope mass balances versus concentration differences of dissolved inorganic carbon – implications for tracing carbon turnover in reservoirs - Barth, Johannes; Mader, Michael; Nenning, Franziska; van Geldern, Robert; Friese, Kurt (Isotopes in Environmental and Health Studies, 2017)

Stable isotopes, elemental distribution and growth rings of belemnopsid belemnite rostra: proxies for belemnite life habitat. - Wierzbowski, Hubert; Joachimski, Michael (Palaios, 2009)
Stables isotopes and elemental composition of two well-preserved belemnite rostra (Hibolithes beyrichi and H. hastatus) from the Bathonian of central Poland were studied. Average temperatures calculated from the oxygen isotope ratios of Hibolithes beyrichi and H. hastatus are 10°C and 6°C, respectively. The absence of highamplitude variations in high-resolution temperature profiles suggests these belemnites lived in deeper waters. This interpretation is compatible with a nektobenthic habitat of belemnopsid belemnites. Carbon isotope ratios of the rostra are assumed to be affected by vital fractionation with prominent fluctuations in the δ 13C records resulting from changes in the metabolic activity. Observed variations in Mg:Ca ratios of the rostra (from 5 mmol-mol -1 to 28 mmol-mol -1) are predominantly a primary signal. Temperature dependence of the Mg:Ca ratio is inferred for H. beyrichi on the basis of a correlation with δ 180 values; however, no such correlation is observed for H. hastatus. No significant correlation is observed between Sr:Ca ratios and δ I80 values in either taxon. Sulphur contents in the rostra vary from 630 ppm to 4400 ppm and are interpreted to be largely coprecipitated with belemnite calcite. Extreme compositions of sulphur are interpreted to result from the incorporation of diagenetic sulphur during early marine diagenesis, which is also characterized in these rostra by high Mg:Ca and Sr:Ca ratios and low δ 13C values. A total number of growth rings in the rostrum of H. beyrichi is calculated at around 600, thus, an expected life span of H. beyrichi is considered to be ∼1.5 years assuming daily precipitation of growth bands. © 2009, SEPM.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.LG.stable

Stable isotope signatures of Middle Paleozoic ahermatypic rugose corals - deciphering vital effects, alteration patterns, and palaeoecological implications - Jakubowicz, Michal; Berkowski, Blazej; López Correa, Matthias; Jarochowska, Emilia; Joachimski, Michael; Belka, Zdzislaw (PLoS ONE, 2015)
This study investigates stable isotope signatures of five species of Silurian and Devonian deep-water, ahermatypic rugose corals, providing new insights into isotopic fractionation effects exhibited by Palaeozoic rugosans, and possible role of diagenetic processes in modifying their original isotopic signals. To minimize the influence of intraskeletal cements on the observed signatures, the analysed specimens included unusual species either devoid of large intraskeletal open spaces ('button corals': Microcyclus, Palaeocyclus), or typified by particularly thick corallite walls (Calceola). The corals were collected at four localities in the Holy Cross Mountains (Poland), Mader Basin (Morocco) and on Gotland (Sweden), representing distinct diagenetic histories and different styles of diagenetic alteration. To evaluate the resistance of the corallites to diagenesis, we applied various microscopic and trace element preservation tests. Distinct differences between isotopic compositions of the least-altered and most-altered skeleton portions emphasise a critical role of material selection for geochemical studies of Palaeozoic corals. The least-altered parts of the specimens show marine or near-marine stable isotope signals and lack positive correlation between δ13C and δ18O. In terms of isotopic fractionation mechanisms, Palaeozoic rugosans must have differed considerably from modern deep-water scleractinians, typified by significant depletion in both 18O and 13C, and pronounced δ13C-δ18O co-variance. The fractionation effects exhibited by rugosans seem similar rather to the minor isotopic effects typical of modern non-scleractinian corals (octocorals and hydrocorals). The results of the present study add to growing evidence for significant differences between Scleractinia and Rugosa, and agree with recent studies indicating that calcification mechanisms developed independently in these two groups of cnidarians. Consequently, particular caution is needed in using scleractinians as analogues in isotopic studies of extinct coral lineages. Answering some of the pertinent palaeoecological questions, such as that of the possibility of photosymbiosis in Palaeozoic corals, may not be possible based on stable isotope data.
UnivIS-Import:2015-10-26:Pub.2015.nat.dgeo.IGM.LP.stable

Stable isotopes (δ18O and δ13C), trace and minor element compositions of Recent scleractinians and Last Glacial bivalves at the Santa Maria di Leuca deep-water coral province, Ionian Sea - López Correa, Matthias; Montagna, Paolo; Taviani, Marco; Vendrell-Simón, Begona; McCulloch, Malcolm (Deep-Sea Research Part Ii-Topical Studies in Oceanography, 2010)
The aragonitic skeletons of bathyal cold-water corals have a high potential as geochemical in situ archives for paleoceanography. Oxygen isotopes and stable carbon isotopes (δ18O and δ13C) have been analyzed, as well as trace and minor element compositions (e.g. Mg/Ca, Sr/Ca, U/Ca, B/Ca and P/Ca) in Lophelia pertusa, one of the most important frame-builders at the Santa Maria di Leuca (SML) deep-water coral hotspot in the Central Mediterranean. The Apulian Bank is swept by strong currents of the Adriatic Deep Water Outflow. The temperature of 13.9 °C is the highest temperature recorded for L. pertusa and provides an important end-member of environmental conditions for geochemical analyses on living Atlantic and Mediterranean cold-water corals. Temperature and salinity (38.77 PSU) are stable throughout the year, and thus virtually no changes should be observed in the stable oxygen isotope signal-if the coral precipitates its skeleton in equilibrium with seawater. We measured various marine properties, such as the seawater oxygen isotope composition (δ18Osw), stable carbon isotope composition (δ13CDIC) of dissolved inorganic carbon (DIC), and dissolved inorganic nutrient concentrations (PO4, NO3, NO2, NH3 and SiO2). Bottom water at the coral sites shows a mean oxygen isotope composition of 1.47‰ δ18Osw-VSMOW, and δ13CDIC showed a mean of 1.1‰ VPDB. A section of a living L. pertusa with a thick theca calcification was probed with a Merchantek MicroMill at a high spatial sampling resolution with 10 samples per 1 mm. This reduced the signal-smoothing inherent to conventional sampling. The δ18Oag of coral aragonite ranges between -2.0‰ and +2.8‰ VPDB and the δ13Cag ranges between -7.77‰ and +1.47‰ VPDB. The Gaussian data distribution for both parameters, including heavy equilibrium values, suggests the completeness of the captured isotopic variability. The strict linear correlation of δ13C and δ18O displays a strong 'kinetic' vital effect. The intercept of the δ13C/δ18O correlation line with the δ13CDIC-composition permits recognition of δ18O equilibrium values of aragonite and thus reconstruction of water temperatures despite strong disequilibrium precipitation. Since the environmental parameters (T, S and δ18Osw) are stable, the entire isotopic signal of the coral must be driven by biological fractionation and might reflect growth speed variations, potentially related to pH variations and changes in the saturation state of the calcifying fluid or seasonally varying nutrient availability. Laser ablation tracks show a trace element composition dependent to microstructural zones (fibrous aragonite vs. centres of calcification). The parabolic relation of the classical temperature proxies Mg/Ca and U/Ca point to trace element vital effects, rendering them unreliable in L. pertusa. The P/Ca ratio shows similar values as Desmophyllum dianthus, for which a linear dependence with seawater phosphate (DIP) has been previously demonstrated. Consequently L. pertusa might be an additional nutrient recorder at bathyal depths. From the same site we also analysed the stable isotopic composition of the Last Glacial pectinid bivalve Pseudamussium peslutrae, which has been radiocarbon-dated (AMS-14C) at 26.3 ka 14C yr BP. The isotope values of the shell calcite document a strongly differing glacial temperature-salinity regime preceding the Holocene coral growth above a prominent hiatus. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LP.stable
Keywords: Cold-water corals; Lophelia pertusa; Stable isotopes; Trace elements; Vital effects

Stable oxygen isotopes - A new approach for tracing the origin of oxide inclusions in steels - Göbbels, Matthias; Pack, Andreas; Hoernes, Stephan; Bross, Rainer; Buhr, Andreas (European Journal of Mineralogy, 2005)
We introduce a new approach for tracing the origin submerged entry nozzle precipitates (clogging) in continuous casting processes using stable oxygen isotopes. The isotopic signatures of possible oxygen sources are compared with the isotope ratios in the precipitates. We use infra-red laser fluorination in combination with continuous flow gas mass spectroscopy to determine the oxygen ratios in the highly refractory, alumina-rich precipitates and possible oxygen sources. Our isotope data indicate that atmospheric oxygen is not the major source of oxide precipitates in the submerged entry nozzles. Also process oxygen from the converter can be excluded to be source of oxygen in clogging. A possible origin of oxygen in alumina-rich precipitates from olivine from refractory material is discussed. © 2005 E. Schweizerbart'sche Verlagsbuchhandlun
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LM.stable
Keywords: Continuous casting; Non-metallic inclusions; Oxygen isotopes

Stable oxygen isotopes of crocodilian tooth enamel allow tracking Plio-Pleistocene evolution of freshwater environments and climate in the Shungura Formation (Turkana Depression, Ethiopia) - Gardin, Axelle; Pucéat, Emmanuelle; Garcia, Géraldine; Boisserie, Jean Renaud; Euriat, Adélaïde; Joachimski, Michael; Nutz, Alexis; Schuster, Mathieu; Otero, Olga (Biogeosciences, 2024)
This study adopts a new approach describing palaeohydrology and palaeoclimates based on the interpretation of stable oxygen isotopes (δ18Op) recorded in fossil crocodilian teeth. They represent an archive of prime interest for tracking freshwater palaeoenvironmental change, applicable to many palaeontological localities in the world: crocodilian teeth are abundant in continental basins and have been widely distributed since their diversification during the Mesozoic; the enamel phosphate is resistant to diagenesis and retains its original isotopic composition over geological timescales; and their δ18Op mainly relies on that of the crocodilian's home waterbody (δ18Ow), which in turn reflects waterbody types, regional climate, and evaporation conditions. This study presents the first application of this theoretical interpretative model to the Shungura Formation (Lower Omo Valley, Ethiopia), a key witness of the important environmental change in eastern Africa during the Plio- Pleistocene that impacted the evolution of regional faunas, including humans. In this complex and variable environmental context, the δ18Op of coexisting crocodilians allows for the fingerprinting of the diversity of aquatic environments they had access to at a local scale. This study sheds light on two important results: the δ18Op of crocodilian teeth (1) indicates stable aquatic environments in the northern Turkana Depression from 2.97 to ca. 2.57 Ma but a decline in local waterbodies diversity after 2.32 Ma, suggesting increasing aridity, and (2) shows, like previous geochemical studies on palaeosols and bivalves in the area, a significant increase in δ18Ow from 2.97 to ca. 1.14 Ma, likely due to the shifting air stream convergence zones between the West African and Indian Summer Monsoons and/or reduced rainfall over the Ethiopian Highlands.
CRIS-Team Scopus Importer:2024-02-16

Stable Sr-isotope, Sr/Ca, Mg/Ca, Li/Ca and Mg/Li ratios in the scleractinian cold-water coral Lophelia pertusa - Raddatz, Jacek; Liebetrau, Volker; Rüggeberg, Andres; Hathorne, Ed; Krabbenhöft, André; Eisenhauer, Anton; Böhm, Florian; Vollstaedt, Hauke; Fietzke, Jan; López Correa, Matthias; Freiwald, André; Dullo, Wolf-Christian (Chemical Geology, 2013)
The aragonitic skeletons of scleractinian cold-water corals can serve as valuable archives in paleoceanographic studies. The potential of δ88/86Sr, Sr/Ca, Mg/Ca, Li/Ca and Mg/Li ratios of the cold-water coral Lophelia pertusa to record intermediate water mass properties has been investigated. Here we used samples from several locations along the European continental margin spanning a large temperature range from 6 to 14°C. Stable strontium isotope measurements were carried out with the recently developed double spike TIMS technique and our results differ from those obtained with less precise methods. In contrast to the strong positive relationship with temperature of previous studies, our results suggest that δ88/86Sr measured in scleractinian cold-water corals is not controlled by seawater temperature, but reflects the Sr isotopic composition of seawater with an offset of δ88/86Sr=-0.196‰.As found in previous studies, the elemental ratios Sr/Ca, Li/Ca and Mg/Li measured in corals are significantly related to water temperature and do not correlate with salinity. Moreover, Sr/Ca ratios in L. pertusa display the expected inverse correlation with temperature. However, the variance in the Sr/Ca data severely limits the accuracy of paleotemperature estimates. The Li/Ca and Mg/Ca ratios reveal other influences besides temperature such as pH and/or growth or calcification rate. However, corresponding Mg/Li ratios in L. pertusa are more tightly related to temperature as they remove these secondary effects. In particular, the Mg/Li ratio in L. pertusa may serve as a new promising paleotemperature proxy for intermediate water masses. Our dataset represents the most extensive geochemical examination of L. pertusa to date, revealing a temperature sensitivity of 0.015. mol/mmol/°C for Mg/Li. However, using this temperature dependence and the precision of 5.3% (2SD) only temperature variations larger than . 1.5°C can be resolved with 95% confidence. © 2013 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LP.temper
Keywords: Cold-water corals; Lophelia pertusa; Mg/Li; Paleotemperature proxy; Sr/Ca; Stable strontium isotopes

Stable water isotope patterns in a climate change hotspot: The isotope hydrology framework of Corsica (western Mediterranean) - van Geldern, Robert; Kuhlemann, Joachim; Schiebel, Ralf; Taubald, Heinrich; Barth, Johannes (Isotopes in Environmental and Health Studies, 2014)

Stacking faults of the hydrous carbonate-containing brucite (HCB) phase in hydrated magnesium carbonate cements - Jansen, Daniel; German, Alexander; Ectors, Dominique; Winnefeld, Frank (Cement and Concrete Research, 2024)
Recently, a hydrous carbonate-containing brucite (HCB) with an approximate composition of MgCO3·35 Mg(OH)2·H2O was postulated as hydration product of binders based on mixtures of reactive magnesia and hydromagnesite (Mg5(CO3)4(OH)2·4H2O). X-ray diffraction showed that the 001 reflection of this phase was split into two reflections at 20 °C, whereas at 60 °C only one reflection occurred. Rietveld refinement revealed that the X-ray pattern of the HCB-phase could be fitted well when a random displacement (stacking faults) and a movement of the layers in x, y and z direction were allowed. The presence of water and/or carbonate leads to different distances between the layers, thus causing the splitting of the 001 reflection. At 60 °C, only carbonate is included in the brucite structure, leading to a similar distance between all brucite layers. The assignment of the additional reflection appearing at 20 °C to a separate, unknown hydrated magnesium carbonate, as suggested in earlier studies, can be excluded.
CRIS-Team Scopus Importer:2024-01-05
Keywords: Brucite; Hydromagnesite; Low-CO; Magnesium carbonate cements; Mineral carbonation

Stapelungsstrukturen von Verbindungen der beta-Tonerde- und Magnetoplumbit-Familien - Ansatz einer strukturellen Systematik - Göbbels, Matthias (Zeitschrift für Kristallographie, Supplement, 1997)
UnivIS-Import:2015-03-05:Pub.1997.nat.dgeo.IGM.LM.stapel

Statistical Approaches Link Sources of Sediment Contamination in Subtropical Reservoirs to Land Use: an Example from the Itupararanga Reservoir (Brazil) - Frascareli, Daniele; Gontijo, Erik Sartori Jeunon; Silva, Sheila Cardoso; Melo, Darllene Silveira; De Castro Bueno, Carolina; Simonetti, Vanessa C.; Barth, Johannes; Carlos, Viviane Moschini; Rosa, Andre Henrique; Friese, Kurt (Water Air and Soil Pollution, 2022)
The identification and characterisation of diffuse pollutant sources in reservoirs remain a challenge due to the complexity of catchments with their variety of land use types. A sediment fingerprinting approach was used in this investigation for determining the sources of contaminants in sediments. By using this approach, we demonstrated how the effects of land use on pollution load of the subtropical Itupararanga Reservoir in Brazil can be de-convoluted. Sediments were collected at seven sampling sites (S1–S7) over the length of the reservoir. This was matched by eight sampling sites (P1–P8) of soils from different land use types (agriculture, urban and forest). Investigated parameters included grain size, total nitrogen (TN), total phosphorus (TP), total carbon (TC), organic matter by loss on ignition (OM), total sulphur (TS), and major ions and metals (Ca2+, Mg2+, Na+, K+, NH4+, SO42−, Cl−, NO3−, As, Al, Ba, Cr, Cu, Fe, Mn, Ni and Zn). Our fingerprinting approach helped to outline horizontal spatial heterogeneities (categorised as riverine, transitional and lacustrine areas) that were attributed mainly to sand (> 26.7%), Si (569 g kg−1) and Cr (336 mg kg−1) at S1 (riverine area). Moreover, fine particles of silt and clay leached from agricultural activities were enriched with OM, TP, TN, TC, As and Cr. These types of sediments were deposited into transitional and lacustrine areas. Furthermore, urban soils were a source of sand and phosphorus to sediments. The fingerprinting method reduced the number of relevant parameters for source identification and helped to identify non-point sources of sediments.
CRIS-Team Scopus Importer:2022-04-29
Keywords: Land use; Non-point pollution sources; Sediment fingerprinting approach; Spatial heterogeneity; Subtropical reservoirs

Statistical independence of escalatory ecological trends in Phanerozoic marine invertebrates - Kießling, Wolfgang; et al. (Science, 2006)
Ecological interactions, such as predation and bioturbation, are thought to be fundamental determinants of macroevolutionary trends. A data set containing global occurrences of Phanerozoic fossils of benthic marine invertebrates shows escalatory trends in the relative frequency of ecological groups, such as carnivores and noncarnivorous infaunal or mobile organisms. Associations between these trends are either statistically insignificant or interpretable as preservational effects. Thus, there is no evidence that escalation drives macroecological trends at global and million-year time scales. We also find that taxonomic richness and occurrence data are cross-correlated, which justifies the traditional use of one as a proxy of the other.
UnivIS-Import:2015-04-14:Pub.2006.nat.dgeo.IGM.LP.statis

Stenolaemate bryozoans from the Graham Formation, Pennsylvanian (Virgilian) at Lost Creek Lake, Texas, USA - Ernst, Andrej; Claußen, Anna Lene; Seuß, Barbara; Wyse Jackson, Patrick (Palaeontologia Electronica, 2022)

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

Stop 1. Diabasbrottet - Ahlberg, Per; Calner, Mikael; Lehnert, Oliver; Maletz, Jörg; Lindskog, Anders (The Ordovician of Västergötland and Dalarna, Sweden. Field guide for the ISOS 14 post-conference excursion, 2023)

Strain migration during multiphase extension, Stord Basin, northern North Sea rift - Fazlikhani, Hamed; Aagotnes, Synne S.; Refvem, Marte A.; Hamilton-Wright, James; Bell, Rebecca E.; Fossen, Haakon; Gawthorpe, Robert L.; Jackson, Christopher A. -L.; Rotevatn, Atle (Basin Research, 2020)
In regions experiencing multiple phases of extension, rift-related strain can vary along and across the basin during and between each phase, and the location of maximum extension can differ between the rift phase. Despite having a general understanding of multiphase rift kinematics, it remains unclear why the rift axis migrates between extension episodes. The role pre-existing structures play in influencing fault and basin geometries during later rifting events is also poorly understood. We study the Stord Basin, northern North Sea, a location characterised by strain migration between two rift episodes. To reveal and quantify the rift kinematics, we interpreted a dense grid of 2D seismic reflection profiles, produced time-structure and isochore (thickness) maps, collected quantitative fault kinematic data and calculated the amount of extension (beta-factor). Our results show that the locations of basin-bounding fault systems were controlled by pre-existing crustal-scale shear zones. Within the basin, Permo-Triassic Rift Phase 1 (RP1) faults mainly developed orthogonal to the E-W extension direction. Rift faults control the locus of syn-RP1 deposition, whilst during the inter-rift stage, areas of clastic wedge progradation are more important in controlling sediment thickness trends. The calculated amount of RP1 extension (beta-factor) for the Stord Basin is up to beta = 1.55 (+/- 10%, 55% extension). During the subsequent Middle Jurassic-Early Cretaceous Rift Phase 2 (RP2), however, strain localised to the west along the present axis of the South Viking Graben, with the Stord Basin being almost completely abandoned. Rift axis migration during RP2 is interpreted to be related to changes in lithospheric strength profile, possibly related to the ultraslow extension (<1 mm/year during RP1), the long period of tectonic quiescence (ca. 50 myr) between RP1 and RP2 and possible underplating. Our results highlight the very heterogeneous nature of temporal and lateral strain migration during and between extension phases within a single rift basin.
CRIS-Team WoS Importer:2020-11-27

Stratigraphical and δ13C records of Permo-Carboniferous platform carbonates, South China: Responses to late Paleozoic icehouse climate and icehouse-greenhouse transition - Liu, Chao; Jarochowska, Emilia; Du, Yuansheng; Vachard, Daniel; Munnecke, Axel (Palaeogeography, Palaeoclimatology, Palaeoecology, 2017)
Little attention has been focused on the stratigraphical imprints of the Late Paleozoic Ice Age on the equatorial eastern Paleo-Tethys. An integrated study of biostratigraphy, microfacies, and stable carbon isotope stratigraphy was carried out on Pennsylvanian-middle Guadalupian carbonates of the Gongchuan section in the Bama Platform, South China. It records seven cooling and two warming pulses in the pre-Kungurian interval, comparing with ice-proximal stratigraphical records and far-field indirect proxies in lower latitudes. A Kungurian negative δC excursion (from +4.4‰ at the base of the Kungurian to +1.6‰) recorded only in the subequatorial belt is documented here. It is followed by a global positive δC trend reaching +5.3‰ near the Cisuralian-Guadalupian boundary. Seven third-order shallowing-upward cycles are reported for the first time from the Kungurian succession. The duration of each cycle is estimated to ca. 1myr. These cycles are interpreted as being of glacioeustatic origin and mainly driven by long-period modulations of obliquity ( 1.2myr) under major pCO decreasing condition. This interpretation is supported by recent climate-ice sheet modeling and Cenozoic glaciation studies, which argue that astronomical forcing will be amplified by large-magnitude perturbations in the carbon cycle, when only localized ice-centers persist. Our results emphasize the need for integration of sedimentological and paleoclimatological proxies in elucidating the dynamics of the deglacial phases of the Late Paleozoic Ice Ag
Keywords: Carbon isotope; Kungurian; LPIA; Orbital forcing; Shallowing-upward cycles

Stratigraphic and oxygen isotope evidence for My-scale glaciation driving eustasy in the Early-Middle Devonian greenhouse world. - Elrick, Maya; Berkyova, Stana; Klapper, Gilbert; Sharp, Zachary; Joachimski, Michael; Fryda, Jiri (Palaeogeography, Palaeoclimatology, Palaeoecology, 2009)
Million year-scale (3rd-order) depositional sequences (few 10s to 100 m-thick) are common in the Devonian marine record and are correlated between sedimentary basins and across widely separated continents implying a eustatic origin. Tectonically driven changes in mid-ocean ridge spreading rates/lengths are too slow to account for the calculated 3rd-order rise/fall rates and typical orbital frequencies ( 20-400 ky) are too fast. We analyzed oxygen isotopes from conodont apatite to evaluate if Early-Middle Devonian 3rd-order sea-level changes were controlled by paleoclimatically driven ice volume (glacio-eustasy) and seawater temperature change (thermo-eustasy). Two successive depositional sequences in the western U.S. (Nevada) and Czech Republic (Prague Basin) were sampled. The δ18O values range from 17.8‰ to 20.2‰ (SMOW) and show similar trends across the Emsian-Eifelian boundary with increasing and peak values in the lower costatus, decreasing values in the mid costatus, and increasing values in the upper costatus to australis zones. The similarities between these widely separated localities indicate that the isotopic trends are global rather than controlled by local variations in seawater temperature, evaporation/freshwater influx, or diagenesis. In the Nevada section, where the sea-level history is the most complete and best understood, the isotopic values increase and peak in late highstand and lowstand system tracts and decrease to the lowest values in the transgressive and maximum flooding intervals suggesting the My-scale sea-level changes were paleoclimatically controlled. The magnitude of isotopic shift from lowstand to maximum flooding intervals ranges from 0.8‰ to 1.5‰ and occurred over time spans of < 1.7 My. The only known mechanism to explain such large and rapid isotopic shifts is glacio-eustasy. If a reasonable range of My-scale subtropical sea surface temperature changes are assumed ( 1-3 °C), then this requires glacio-eustatic sea-level changes of > 35 m to explain the remaining isotopic shifts. These amplitudes imply that significant continental ice sheets grew and melted on the < 1.7 My time scales during the Early-Middle Devonian and, like recent reports for the mid-Cretaceous and early Eocene, challenge previous assumptions of ice-free greenhouse climates. A plausible climate driver for these My-scale paleoclimate changes is long-period eccentricity ( 2.4 My) and obliquity ( 1.2 My) variations. © 2009 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.LG.strati
Keywords: Conodont apatite; Devonian; Glaciation; Glacio-eustasy; Greenhouse; Oxygen isotopes

Stratigraphic ranking of selected invertebrate fossils: A quantitative approach at different temporal and geographic scales - Abdelhady, Ahmed; Seuß, Barbara; Hassan, Hatem (Palaeontologia Electronica, 2019)
Fossil groups are used for biochronological dating of rocks for decades. This manuscript presents a quantitative approach to appraise and compare the quality of selected taxa as biostratigraphic markers. Based on species occurrence of ammonites, bivalves, and planktic and benthic foraminifers we evaluate the potential of these to rank them quantitatively. The spatiotemporal analyses of occurrence data (species duration, geographic range) were integrated in results of the Unitary Association method, which measures superpositional contradictions in addition to the generation of a number of UAs. The results indicate that Jurassic ammonites have the lowest species duration, and that the majority of species is confined to a single UA-zone. Additionally, ammonites have the lowest numbers of contradicted bio-events. However, planktic foraminifers are more valuable at least in the Cenozoic as they have a high geographic reproducibility and diversity, and higher ISP values. The bivalves and benthic foraminifers both show longer average species durations and more superpositional contradictions per species. Therefore, their biostratigraphic potential is more limited at an interregional scale. The shorter species durations of ammonites and planktic foraminifers in the studied sections can be attributed to their higher extinction rates. As an advantage to simple spatio-temporal analyses, the UA-method can accurately assess the stratigraphic potential of a given taxonomic group. The results obtained herein indicate that the life-habit has direct impact on the species duration and thus, the stratigraphic potential of the fossil groups. Based on the results achieved from this study, an index for ranking fossil groups (Index of Stratigraphic Potential ‘ISP’) is introduced.<br

Stratigraphy, metamorphism and nappe‑tectonics in the Shackleton Range (Antarctica). - Buggisch, Werner; Kleinschmidt, Georg; Kreuzer, Hans; Krumm, Stefan (Geodätische und geophysikalische Veröffentlichungen. Reihe I, 1990)
UnivIS-Import:2015-03-05:Pub.1990.nat.dgeo.IGM.LG.strati

Stratigraphy modeling and thermal conductivity computation in areas characterized by Quaternary sediments - Teza, Giordano; Galgaro, Antonio; Destro, Elisa; Di Sipio, Eloisa (Geothermics, 2015)
Keywords: Geoexchange; Borehole heat exchanger; Thermal ground characterization; Stratigraphy; Thermal conductivity; Spatial statistics

Strengthening confidence in climate change impact science - O'Connor, Mary; Holding, Johnna; Kappel, Carrie; Duarte, C. M.; Brander, K.; Brown, C. J.; Bruno, J. F.; Buckley, L.; Burrows, M. T.; Halpern, B. S.; Kießling, Wolfgang; Moore, P.; et al. (Global Ecology and Biogeography, 2015)
Keywords: Abundance; Attribution; Climate change; Distribution; Hypothesis; Impacts; Marine; Phenology; Scientific method; Time series

Stress sensitivity of porosity and permeability under varying hydrostatic stress conditions for different carbonate rock types of the geothermal Malm reservoir in Southern Germany - Bohnsack, Daniel; Potten, Martin; Freitag, Simon; Einsiedl, Florian; Zosseder, Kai (Geothermal Energy, 2021)
In geothermal reservoir systems, changes in pore pressure due to production (depletion), injection or temperature changes result in a displacement of the effective stresses acting on the rock matrix of the aquifer. To compensate for these intrinsic stress changes, the rock matrix is subjected to poroelastic deformation through changes in rock and pore volume. This in turn may induce changes in the effective pore network and thus in the hydraulic properties of the aquifer. Therefore, for the conception of precise reservoir models and for long-term simulations, stress sensitivity of porosity and permeability is required for parametrization. Stress sensitivity was measured in hydrostatic compression tests on 14 samples of rock cores stemming from two boreholes of the Upper Jurassic Malm aquifer of the Bavarian Molasse Basin. To account for the heterogeneity of this carbonate sequence, typical rock and facies types representing the productive zones within the thermal reservoir were used. Prior to hydrostatic investigations, the hydraulic (effective porosity, permeability) and geomechanical (rock strength, dynamic, and static moduli) parameters as well as the microstructure (pore and pore throat size) of each rock sample were studied for thorough sample characterization. Subsequently, the samples were tested in a triaxial test setup with effective stresses of up to 28 MPa (hydrostatic) to simulate in-situ stress conditions for depths up to 2000 m. It was shown that stress sensitivity of the porosity was comparably low, resulting in a relative reduction of 0.7–2.1% at maximum effective stress. In contrast, relative permeability losses were observed in the range of 17.3–56.7% compared to the initial permeability at low effective stresses. Stress sensitivity coefficients for porosity and permeability were derived for characterization of each sample and the different rock types. For the stress sensitivity of porosity, a negative correlation with rock strength and a positive correlation with initial porosity was observed. The stress sensitivity of permeability is probably controlled by more complex processes than that of porosity, where the latter is mainly controlled by the compressibility of the pore space. It may depend more on the compaction of precedented flow paths and the geometry of pores and pore throats controlling the connectivity within the rock matrix. In general, limestone samples showed a higher stress sensitivity than dolomitic limestone or dolostones, because dolomitization of the rock matrix may lead to an increasing stiffness of the rock. Furthermore, the stress sensitivity is related to the history of burial diagenesis, during which changes in the pore network (dissolution, precipitation, and replacement of minerals and cements) as well as compaction and microcrack formation may occur. This study, in addition to improving the quality of input parameters for hydraulic–mechanical modeling, shows that hydraulic properties in flow zones largely characterized by less stiff, porous limestones can deteriorate significantly with increasing effective stress.
CRIS-Team Scopus Importer:2021-06-11
Keywords: Carbonate; Effective stress; Geothermal energy; Hydrostatic; Malm; Molasse Basin; Permeability; Poroelastic; Porosity; Stress sensitivity

Stromatoporoid-coral reefs and platform deposits from the Silurian of Gotland - Munnecke, Axel (Mémoires du Muséum national d'Histoire naturelle, 2007)
Keywords: Stromatoporoids; corals; reefs; platform deposits; Silurian; Gotland

Structural and elemental analysis of the freshwater, low-Mg calcite coralline alga Pneophyllum cetinaensis - Ragazzola, Federica; Kolzenburg, Regina; Zekonyte, Jurgita; Teichert, Sebastian; Jiang, Chulin; Žulevíc, Ante; Caragnano, Annalisa; Falace, Annalisa (Plants, 2020)

Structural and geochemical assessment of the coralline alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica - López Correa, Matthias; Teichert, Sebastian; Ragazzola, Federica; Cazorla Vázquez, Salvador; Engel, Felix; Hurle, Katrin; Mazzoli, Claudio; Kuklinski, Piotr; Raiteri, Giancarlo; Lombardi, Chiara (Minerals, 2023)
Crustose coralline algae (CCA) occur from the tropics to the poles in photic benthic environments. Here, we report on some of the world’s southernmost and coldest CCA sites in Terra Nova, Ross Sea, Antarctica at 74°41′ S. The recently described red alga Tethysphytum antarticum is investigated for its skeletal architecture, its mineralogical and geochemical composition, as well as for its taxonomic classification. A phylogenetic analysis based on molecular genetics and the sequencing of the photosystem II protein D1 (psbA) gave a perfect match with T. antarcticum. Histological sections and micro-CT-scans provide new diagnostic details for the conceptacles (the reproductive organs of the alga). X-ray diffractometry and electron-microprobe measurements yielded a clear high-Mg calcite ( 8 mol%) composition of the skeletal parts. Detailed back-scattered electron imaging of polished petrographic thin sections revealed a two-layered thallus (vegetative plant tissue), comprising an organic-rich irregularly calcified basal layer with rectangular cells, overlain by the main thallus. Elemental maps show relatively increased sulphur in the basal layer, clearly tied to organic cell walls. MgCO3 and SrCO3 were targeted with semiquantitative elemental mappings and in an ontogenetic quantitative spot transect. Compared with temperature (−1.95 °C to +1.08 °C), the MgCO3 (mol%) reflects this world’s coldest CCA site temperature with the lowest MgCO3 content of 7.9 ± 1.6 mol%. The along transect variability, however, shows with 6 mol% a larger MgCO3 variability than expected for the 3 °C intra-annual temperature amplitude in Terra Nova Bay. This implies that in low amplitude settings the biomineralisation control on Mg/Ca ratios can outcompete its temperature sensitivity. Mark-recapture studies, next to the environmental logger station La Zecca are suggested, to perform a detailed growth rate and biomineralisation quantificatio
Keywords: crustose coralline algae; Antarctica; taxonomy; phylogeny; thallus structure; biomineralization; geochemistry; climate change

Structural evidence for sinistral displacement on the Wegener Fault in southern Nares Strait, Arctic Canada - von Gosen, Werner; Piepjohn, K.; Gilotti, J. A.; Mcclelland, W. C.; Reinhardt, L. (Circum-Arctic Structural Events: Tectonic Evolution of the Arctic Margins and Trans-Arctic Links with Adjacent Orogens, 2019)
The sinistral Wegener Fault in the Nares Strait between northwest Greenland and eastern Ellesmere Island (Canadian Arctic) represents a tectonic element in the Arctic whose existence and significance have been controversial for more than 50 years. Some workers interpret the Wegener Fault as an important early Tertiary transform related to movement of the Greenland plate relative to the North American plate. Others view it as insignificant or reject its existence. While onshore studies in the Canadian portion of the northern Nares Strait region have proven the existence of important sinistral strike-slip faults related to the offshore Wegener Fault, the southern continuation of the Wegener Fault in the southern Kane Basin and Smith Sound is unclear. In particular, Smith Sound has been interpreted as a location of an undisturbed continuation of the Proterozoic basement from Greenland to Ellesmere Island, with only one possible location of the Wegener Fault near the east coast of Ellesmere Island.
CRIS-Team WoS Importer:2019-11-15

Structural investigations of selected phases in the system Ca2SiO4 * Ca3(PO4)2 using XRPD and Rietveld method - Müller, Ralf; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (2001)
UnivIS-Import:2015-03-09:Pub.2001.nat.dgeo.IGM.LM.struct

Structurally and climatically-controlled progressive destabilisation of a multi-unit carbonate rockslide with marly interlayers over two decades (Hornbergl, Tyrol/Austria) - Ettenhuber, Regina; Moser, Michael; Krautblatter, Michael; Paysen-Petersen, Lukas (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 2022)
Rockslides in intercalated carbonate rocks are among the most common and hazardous rock slide types in the European Alps and other mountains worldwide. Progressive shear plane development in marly or clayey interlayered lime-stones is an issue of debate, especially since the disastrous 200 million m3 carbonate rockslide in Vajont in 1963. Since in-terlayers are often not persistently developed, the processes controlling the progressive shear plane evolution in carbonate rockslides affecting acceleration and deceleration phases are poorly understood. This paper discusses 20 years of progressive shear plane development in a 10 million m3 multi-unit rockslide with marly interlayers (Hornbergl, Austria). We present a two-decade kinematic record, complemented with field mapping, surface geodetical observations, subsurface geophysical investigations, rock and soil mechanical laboratory testing, a snow-referenced infiltration model, as well as a resulting dis-continuum mechanical model. Monthly tape extensometer measurements (3,300 individual measurements) from 1996 to 2016, mapping and geodetic investigations reveal mean absolute displacement rates of 0.2-14.5 mm/month between multi-ple units of the translational rockslide, often separated by > 20 m deep and meter-wide open fractures. Electrical resistivity tomography (ERT) uncovers the geological and structural setting of the upper 40 m of the rockslide's inner structure. Labo-ratory analysis shows that full (100%) saturation of marly interlayers decreases the cohesion from 65 to 21 kPa in compari-son to 50% saturation, presumably explaining seasonal velocity variations. Correspondingly, infiltration models including snow accumulation and melt appear to control movement patterns in some years after snow melt and after heavy convective rainfalls. Discontinuum mechanical models based on mapping, geophysical reconnaissance and mechanical laboratory test -ing show that the multi-unit rockslide is at the fringe of stability with 50% water saturation in marly interlayers and that strain rates rapidly accelerate with the cohesion loss upon their full water-saturation matching with the described kinematic record. Over multiple years, compression and decompression waves between rockslide units become a first order control for progressive rockslide development. Here we show in a 20-year multi-unit rockslide record, that infiltration after snowmelt and extreme precipitation may control monthly and seasonal patterns of carbonate rockslide defor mation, but compression and decompression waves may become key control on a multiannual time scale for progressive destabilisation.
CRIS-Team WoS Importer:2022-10-07

Structure and interactions in benzamide molecular crystals - Ectors, Philipp; Ectors, Dominique; Zahn, Dirk (Molecular Simulation, 2013)
In this study, we resolved discrepancies concerning the experimentally determined structure of benzamide molecular crystals from dispersion-corrected density functional calculations. A clear energy ranking was obtained for the two candidates of the stable (P1) modification of benzamide. This was rationalised by subtle differences of the molecular interactions in the molecular crystal. The potential energy of the different structures was dominated by the interplay of intermolecular attraction and molecular torsion/deformation to accommodate favourable hydrogen-bonded networks. Using suitable proxies arranged in pseudo-crystalline set-ups, we discriminated the contribution of electrostatics, π-π interactions and intra-molecular interactions to the lattice energies. © 2013 Taylor and Francis.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LM.struct
Keywords: crystal structure; density-functional theory calculations; molecular interactions; polymorphism

Structure and principles of oxidic hexaphases: A review - Klemenz, Lisa; Richter, Andreas; Langhof, Nico; Göbbels, Matthias (Open Ceramics, 2021)
This paper is about the general structure and the formation of oxidic hexaphase types according to their crystal chemistry. Oxidic hexaphases exhibit hexagonal symmetry and consist of mixed layer structures stacked along the crystallographic c-axis. There are two main types of hexaphases: the magnetoplumbite and β-alumina type. Every hexaphase has a spinel structure that integrates blocks with either a rock salt or β-alumina structure. Both block types contain a characteristic cation. The formation of oxidic hexaphases depends on various factors: In addition to the size and charge of the characteristic cation the size of the spinel block in the crystallographic a-b direction is a decisive factor. Furthermore, the spinel block can be modified by replacing the present trivalent scaffolding cations with bivalent cations, resulting in more complex hexaphases such as the X, W, Z and Y types or β‴ types.
CRIS-Team Scopus Importer:2021-07-02
Keywords: Beta-alumina; Hexaaluminates; Magnetoplumbite; Mixed layer; Stacking

Studies of the stability, nucleophilic substitution reactions, DNA/BSA interactions, cytotoxic activity, DFT and molecular docking of some tetra- and penta-coordinated gold(iii) complexes - Radisavljevic, Snezana; Kesic, Ana Dekovic; Cocic, Dusan; Puchta, Ralph; Senft, Laura; Milutinovic, Milena; Milivojevic, Nevena; Petrovic, Biljana (New Journal of Chemistry, 2020)
Two gold(iii) complexes, square-planar [Au(DPP)Cl-2](+)(1) and distorted square-pyramidal [Au(DMP)Cl-3] (2) (where DMP = 2,9-dimethyl-1,10-phenanthroline and DPP = 4,7-diphenyl-1,10-phenanthroline), were studied by different experimental methods. Their stability in water and in buffer solution (25 mM Hepes, 30 mM NaCl, pH = 7.2) was investigated by UV-Vis spectroscopy while their redox stability is confirmed by CV. Substitution reactions between complexes1and2, and biologically relevant ligands, such as thiourea (Tu), guanosine-5 '-monophosphate (5 '-GMP), glutathione (GSH) andl-methionine (l-Met), were studied by a stopped-flow technique, under the pseudo-first order conditions as a function of ligand concentration and temperature. According to the values of the activation parameters, all studied reactions followed an associative substitution mechanism. DNA binding studies of complexes1and2were performed by UV-Vis and fluorescence spectroscopy and viscosity measurements, as well as interactions with bovine serum albumin (BSA). Density functional theory (DFT) was implemented in order to analyse the wave function of the optimized structures to get better insight into the binding interactions between the inert ligands and gold(iii) center. The experimental results of binding studies with DNA and BSA were simulated and compared by performing a molecular docking study. All results demonstrate the strong connection between the reactivity of the complexes toward biologically important targets and their structural and electronic characteristics. The cytotoxic activity of complexes1and2against different cell lines (MDA-MB-231, HCT-116, and HaCaT) was evaluated 24 and 72 h after treatments. The results indicate reduced viability of cell lines in a time- and dose-dependent manner.
CRIS-Team WoS Importer:2020-07-24

Studies on the early hydration of two modifications of ye'elimite with gypsum - Jansen, Daniel; Spies, Alexandra; Neubauer, Jürgen; Ectors, Dominique; Götz-Neunhoeffer, Friedlinde (Cement and Concrete Research, 2017)
Two modifications of ye'elimite (namely orthorhombic ye'elimite (stoichiometric CA) and iron-containing cubic ye'elimite (CAF)) were synthesized and the reactions without additional sulfate and with gypsum were tracked by means of heat flow calorimetry. Without gypsum the reaction differs significantly for both modifications while the addition of gypsum leads to almost comparable reactions. With addition of gypsum two distinct heat flow maxima could be detected while the reaction without gypsum showed only one distinct maximum for both modifications. For the systems with gypsum additional experiments were performed namely in-situ XRD, NMR, thermodynamic modeling, TGA and pore solution composition. It could be shown that the reaction with gypsum shows two steps of ettringite precipitation for both modifications. The two steps show significant differences. During the first step of ettringite precipitation gypsum and ye'elimite and free water are consumed forming ettringite and a highly hydrated AH. The second ettringite precipitation is powered by ye'elimite consumption but no further gypsum dissolution. In addition, water is removed from the AH used up for the second ettringite precipitation. The two modifications of ye'elimite react comparable with gypsum but show slightly different heats of hydration when reacting with the same calcium sulfate (gypsum) during early hydration; this is due to slightly lower reaction turnover of the cubic, iron-containing modification leading to slightly reduced ettringite formatio

Study of hydration potential and kinetics of the ferrite phase in iron-rich CAC - Hertel, Tobias; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (Cement and Concrete Research, 2016)
With the presence of CA, the hydration kinetics of ferrite phase is influenced and decreased dramatically. Heat flow measurements, QXRD data, and heat flow calculations show concordantly that hydration of ferrite in mix with CA is retarded until the onset of CA hydration and that less ferrite is dissolved. Analysis of the liquid phase of CA paste and CAC-like cement paste displayed significant higher concentrations of Al and Ca compared with pure ferrite paste. Thus, the composition of the liquid phase is set by initial dissolution of CA. We assume that an instant dissolution of the ferrite phase is blocked when solubility equilibrium is dominated by CA. Dissolution of ferrite is only possible after massive precipitation of hydrates and reduction of Ca and Al concentration in the liquid phase.
Keywords: Calcium aluminate cement(D); Calcium aluminoferrite (D); Calorimetry (A); Pore solution (B); X-ray diffraction (B)

Study of thermal migration and induced mechanical effects in double U-tube energy piles - Luo, Jin; Zhao, Haifeng; Gui, Shuqiang; Xiang, Wei; Rohn, Joachim (Computers and Geotechnics, 2017)
This paper investigates two geothermal energy piles using thermal response tests (TRTs). A set of parameters including pile wall temperature, ground temperature and strain are monitored at four different depths. The thermally induced mechanical behavior of the energy piles are then analyzed based on the monitoring data. The results show the following: (1) The temperature at the pile wall clearly varies throughout the heating and cooling cycle, and the ground temperature distribution shows a delay compared to the TRT stages. (2) The thermally induced mechanical effects are influenced by both the temperature and restraint conditions. © 2017 Elsevier Ltd
Keywords: Geothermal energy; Energy piles; Ground temperature; Heating and cooling cycles; Mechanical behavior; Mechanical effects; Restraint conditions; Thermal migration; Thermal response test; Piles; cooling; geothermal energy; heating; mechanical property; pile response; strain; temperature effect

Study on a fossil nautiloid – surprising insights - Seuß, Barbara (Annual Meeting of the Paläontologische Gesellschaft, 2012)
The Buckhorn Asphalt Quarry in Oklahoma, USA, yields a Desmoinesian (Upper Carboniferous) faunal assemblage of outstanding preservation caused by synsedimentary or contemporary impregnation of sediments and fauna with hydrocarbons. These hydrocarbons prevented diagenetic processes to a high degree. The faunal assemblage evolved in a (sub)tropical shallow marine setting and is, with more that 160 reported species, one of the most diverse Paleozoic faunas known to date. The succession is strongly dominated by molluscs, i.e., gastropods, cephalopods, and bivalves, accompanied by e.g., fusulinids, ostracods, echinoderms, and bryozoans. The sediments are mainly mixed siliciclastic-carbonatic and exhibit a single cycle of trans- and regression, with cephalopod-dominated sediments ("cephalopod coquina") representing the deepest marine deposits. Two cephalopod shell remains from the cephalopod coquina were selected for a detailed isotope study (O, C). One shell remain derives from a so far unidentified specimen, the second one from an orthoconic nautiloid which was tentatively assigned to Hebetorthoceras unicamera. Hebetorthoceras is characterized by preservation of two chambers of the phragmocone with nicely preserved cameral and siphuncular deposits. Before samples were prepared the shell remains were intensively studied by using SEM, EDX, XRD-GADDS, and by a series of thin sections. As expected, original shell microstructure and material were still preserved accompanied by parts influenced by diagenetic alteration. Anyhow, both altered and unaltered shell material and both, cameral deposits and shells were sampled with high resolution. Primary isotope signals were used to recalculate local paleotemperatures (unidentified remain: 28-31°C; Hebetorthoceras: 14-15°C) for the sea covering the area of the Buckhorn Asphalt Quarry. Samples exhibiting diagenetic alteration were used to reconstruct diagenetic pathways within the cephalopod remains. So far so good, if there weren't two distinct oval marks on the outside of Hebetorthoceras and the rather abnormal formation and mineralogy of the cameral deposits of this specific specimen. In a subsequent study both, the oval marks and the cameral deposits were examined and it turned out, that a) Hebetorthoceras was victim of a predator, b) this attack was sublethal, c) the specimen was able to precipitate further cameral deposits after the assault, d) it precipitated high magnesium-calcitic cameral deposits during lifetime, and e) the HMC was not a reaction to the heavy injury caused by the attack, but was even formed before. Please download the supplementary material for details on this presented stud

Study on operation management of borehole heat exchangers for a large-scale hybrid ground source heat pump system in China - Luo, Jin; Zhao, Haifeng; Jia, Jia; Wei, Xiang; Rohn, Joachim; Blum, Philipp (Energy, 2017)
For large-scale Ground Source Heat Pump (GSHP) systems, the numerous Borehole Heat Exchangers (BHEs) are generally managed in units. The simultaneous operation of BHEs consume huge amount of energy by operating water-circulating-pumps. However, such an operation condition may waste energy when no peak thermal load is needed. Hence, operation management should be optimized according to timely energy demand to ensure efficient performance with minimum maintenance. In this paper, three operation conditions for a cooling load dominated GSHP system in China are studied. First, specific ground conditions of the BHE field are investigated. The GSHP system operation under intermittent heating and cooling conditions is simulated by Thermal Performance Test (TPT). In order to examine performance of the BHEs and ground temperature migration, a numerical heat transport model is developed. Modeling results indicate similar thermal performance of BHEs and ground temperature disturbance among the three operation alternatives over a 25-year period. Finally, economic performance and operating savings are analyzed. The optimized operation condition in which the operating numbers of BHEs was designed with monthly energy demand of the building could save around 25,000 CNY (∼3000 EUR) annually. © 2017 Elsevier L
Keywords: Energy management; Heat exchangers; Heat pump systems; Pumps; Borehole heat exchangers; Economic performance; Intermittent heating; Minimum maintenances; Operation conditions; Simultaneous operation; Thermal Performance; Water circulating pumps; Geothermal heat pumps; borehole; cooling; fuel consumption; ground conditions; heat transfer; heating; optimization; performance assessment; China

Stylolites and stylolite networks as primary controls on the geometry and distribution of carbonate diagenetic alterations - Gomez-Rivas, Enrique; Martin-Martin, Juan Diego; Bons, Paul D.; Köhn, Daniel; Griera, Albert; Trave, Anna; Llorens, Maria-Gema; Humphrey, Elliot; Neilson, Joyce (Marine and Petroleum Geology, 2022)
There is ongoing debate on whether stylolites act as barriers, conduits, or play no role in fluid transport. This problem can be tackled by examining the spatial and temporal relationships between stylolites and other diagenetic products at multiple scales. Using the well-known Lower Cretaceous Benic`assim case study area (Maestrat Basin, E. Spain), we provide new field and petrographic observations of how bedding-parallel stylolites can influence different diagenetic processes during basin evolution. The results reveal that stylolites can serve as baffles or inhibitors for different carbonate diagenetic reactions, and act as fronts for dolomitization, dolomite recrystallization and dolomite calcitization processes. Anastomosing stylolites that pre-date burial dolomitization probably acted as a collective baffle for dolomitization fluids in the study area, resulting in stratabound replacement geometries at the metre-to-kilometre scale. The dolomitization front coincides with stylolites, and can be traced along consecutive anastomosing ones. Such anastomosing stylolites are typical of mud-dominated facies that characterize limestone-dolostone transition zones. Conversely, dolostone bodies tend to correspond to more grain-dominated facies characterized by parallel (non-anastomosing) stylolites. Stylolites subsequently acted as fluid flow conduits and barriers when the burial and stress conditions changed. Stylolitic porosity enhanced by dissolution within dolostones close to faults appears filled with saddle dolomite riming the stylolite pore, and high-temperature blocky calcite cements filling the remaining porosity. The fluids responsible for these reactions were likely released from below at high pressure, causing hydraulic brecciation, and were channelised through stylolites, which acted as fluid conduits. Stylolites are also found acting as baffles for subsequent dolomite calcitization reactions during meteoric diagenesis and occasionally appear filled with iron oxides likely released by calcitization. This example demonstrates how the same type of stylolites (bedding-parallel) can act as barriers/inhibitors and/or conduits for different types of diagenetic reactions through time, and how important it is to consider their collective role when they form networks.
CRIS-Team WoS Importer:2022-02-11

Subaqueous rock-avalanche deposits exposed by post-glacial isostatic rebound, Innfjorddalen, Western Norway - Schleier, Markus; Hermanns, Reginald L.; Gosse, John C.; Oppikofer, Thierry; Rohn, Joachim; Tonnesen, Jan F. (Geomorphology, 2017)
This paper presents a detailed description of deposits and landforms of multiple rock avalanches in Western Norway, one of which fell onto water-saturated sediments in Innfjorddalen below the former water level. Deposits of the latter are now exposed on the valley floor due to post-glacial isostatic rebound. At least three rock avalanches from the same source at Gråfonnfjellet Mountain have occurred during late glacial and post-glacial time, and their deposits are distributed over an area of 1.44 km2 in the valley. These rock avalanches have volumes of 15.1 × 106 m3, 5.4 × 106 m3 and 0.3 × 106 m3 and yielded cosmogenic radionuclide 10Be ages of 14.3 ± 1.4 ka, 8.79 ± 0.94 ka and 1.028 ± 0.380 ka, respectively. The youngest event dates, within uncertainty limits to a historic rock avalanche in the year 1611–12 CE. The rock avalanches formed a stratified succession of deposits. The rock-avalanche deposits (1.38 m2) have lobate forms, have frontal rims and parallel ridges, extend across the valley floor and up the opposite slope, and form dams on the valley floor. Isolated hills comprised of rock boulders (0.61 km2), interpreted to be ‘toma hills’, are disconnected from the main rock-avalanche deposits by a 520-m-wide zone of deformed, valley-fill sediments. Trenches and a ground penetrating radar survey of these deposits indicate large-scale deformation or liquefaction. Numerical runout modeling of the rock avalanches with the code DAN3D supports the interpretation of their landforms and sources, and highlights their runout behavior. © 2016 Elsevier B.V.
Keywords: cosmogenic radionuclide; dating method; fjord; landform; mountain region; numerical model; Postglacial; rock avalanche; Norway

Subarctic Holocene climatic and oceanographic variability in Stjernsund, Northern Norway: evidence from benthic foraminifera and stable isotopes - Joseph, Nina; López Correa, Matthias; Schönfeld, Joachim; Rüggeberg, Andres; Freiwald, André (Boreas, 2013)
A high-resolution record, covering 9.3-0.2ka BP, from the sub-arctic Stjernsund (70°N) was studied for benthic foraminiferal faunas and stable isotopes, revealing three informally named main phases during the Holocene. The Early- to Mid-Holocene (9.3-5.0ka BP) was characterized by the strong influence of the North Atlantic Current (NAC), which prevented the reflection of the Holocene Climatic Optimum (HCO) in the bottom-water temperature. During the Mid-Holocene Transition (5.0-2.5ka BP), a turnover of benthic foraminiferal faunas occurred, Atlantic Water species decreased while Arctic-Polar species increased, and the oxygen isotope record showed larger fluctuations. Those variations correspond to a period of global climate change, to spatially more heterogeneous benthic foraminiferal faunas in the Nordic Seas region, and to regionally diverging terrestrial temperatures. The Cool Late Holocene (2.5-0.2ka BP) was characterized by increased abundances of Arctic-Polar species and a steady cooling trend reflected in the oxygen isotopes. In this period, our record differs considerably from those on the SW Barents Sea shelf and locations farther south. Therefore, we argue that regional atmospheric cooling triggered the late Holocene cooling trend. Several cold episodes centred at ∼8.3, ∼7.8, ∼6.5, ∼4.9, ∼3.9 and ∼3.3ka BP were identified from the benthic foraminiferal faunas and the δ18O record, which correlated with marine and atmospherically driven proxy records. This suggests that short-term cold events may result from reduced heat advection via the NAC or from colder air temperatures. © 2012 The Authors. Boreas © 2012 The Boreas Collegium.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LP.subarc

Subduction and exhumation mechanisms of ultra-high and high-P oceanic and continental crust at Makbal (Tianshan, Kazakhstan and Kyrgyzstan) - Meyer, Melanie; Klemd, Reiner; Hegner, E.; Konopelko, Dmitry (Journal of Metamorphic Geology, 2014)
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.c3geoc.subduc

Subduction channel fluid–rock interaction and mass transfer: Constraints from a retrograde vein in blueschist (SW Tianshan, China) - Li, Jilei; John, Timm; Gao, Jun; Klemd, Reiner; Wang, Xin-Shui (Chemical Geology, 2017)
One widely neglected part of the subduction zone fluid cycle is the retrograde fluid flow along the plate interface. This fluid flow may facilitate the exhumation of slab-derived rocks within the subduction channel. However, our understanding on the nature and behavior of these retrograde fluids is still insufficient. Retrograde veins preserved in HP–UHP rocks can provide valuable information about fluid activities and mass transfer at the plate interface and exhumation processes. In this study, we present a petrological and geochemical investigation of a typical retrograde vein and its blueschist host rock, which occurs throughout the whole Akeyazi (U)HP terrane in the Chinese southwestern Tianshan. The magnetite-bearing albite–calcite vein, representing an external fluid pathway, crosscuts the host blueschist that mainly consists of glaucophane, garnet, epidote and titanite. Along the fluid conduit the immediate wall-rock experienced greenschist-facies overprinting as displayed by an albite-rich selvage that grades into a chlorite–biotite selvage towards the host rock. The replacements of garnet by chlorite and glaucophane by albite are thought to have occurred due to an interface-coupled dissolution-precipitation mechanism. Mass balance calculations show that during fluid–rock interaction large amounts of LILE (K–Rb–Ba–Cs and Pb), Cu and CO2 were added to the selvages (mass gain > 200%), whereas the altered wall-rock released significant amounts of Ca, Li, Sr, REE and transition metal elements (V–Mn–Co–Ni–Zn) (mass loss mainly between 40 and 100%) due to the dissolution of glaucophane, garnet and epidote. The chlorite–biotite selvage experienced additional SiO2 and Na2O mass losses as well as FeO, MgO and H2O mass gains, whereas the albite-rich selvage underwent exactly the opposite mass transfer with respect to these components. The Al, Ti, Nb, Ta and Cr contents were constant during the alteration. Therefore, the retrograde fluid causing greenschist-facies overprinting of the blueschist host in the subduction channel (at ca. 30 km depth) is proposed to be oxidized and enriched in LILE, Cu and CO2components, whereas Ca, Li, Sr, REE, Y and transition metal elements (V–Mn–Co–Ni–Zn) are thought to have been mobilized during fluid-rock interaction. In addition, the main fluid sources (sediments, oceanic crust or serpentinites) diversely contribute to retrograde fluids at different depths in the subduction channel.<br
Keywords: Element mobility; Fluid–rock interaction; Retrograde fluid flow; Albite vein; Blueschist; Tianshan

Subduction initiation of the Neo-Tethys oceanic lithosphere by collision‐induced subduction transference - Wang, Xuhui; Lang, Xinghai; Klemd, Reiner; Deng, Yulin; Tang, Juxing (Gondwana Research, 2022)
Collision-induced subduction transference may have triggered subduction of the Neo-Tethys oceanic lithosphere. To verify this proposition, we present an integrated geochemical and geochronological studies of new and published data of the Permian-Triassic magmatism in the Lhasa Terrane. The newly identified Chongni mafic intrusions (gabbros and diorites) in the North Lhasa Terrane (NLT) were emplaced during the Early Permian (ca. 275 Ma). The mafic rocks have (87Sr/86Sr)t ratios between 0.7037 and 0.7042, and εNd(t) values between + 5.2 and + 5.8. The zircons of the Chongni mafic rock samples have εHf(t) values from + 9.1 to + 12.9. The isotopic data in conjunction with trace element features suggest that the Chongni mafic intrusions have been derived mainly by partial melting of a metasomatized mantle wedge source. The newly identified Quxu granodiorites and hornblende gabbros in the South Lhasa Terrane (SLT) were emplaced in the Late Triassic (ca. 228–203 Ma). The granodiorites are characterized by (87Sr/86Sr)t ratios of 0.7036–0.7037 and εNd(t) values of +6.6 to +6.7, while the hornblende gabbro samples have (87Sr/86Sr)t ratios of 0.7033–0.7035 and εNd(t) values of +7.3 to +7.4. The zircons of the granodiorite and hornblende gabbro samples revealed εHf(t) values of +10.3 to +14.0 and +10.8 to +16.4, respectively. The isotopic data in combination with trace element signatures suggest that the granodiorites were derived from a juvenile basaltic lower crust with a minor input of mantle components, while the hornblende gabbros are interpreted to have formed during partial melting of a formerly metasomatized depleted mantle wedge source. The Early Permian and Late Triassic magmatic rocks consistently show arc-related signatures, which probably record the northward subduction of the Sumdo Paleo-Tethys and the Neo-Tethys oceanic slabs, respectively. This evidence, in combination with that of other studies on the Permian-Triassic magmatism across the Lhasa Terrane, indicates that arc magmatism within the NLT switched to collisional magmatism at ca. 260 Ma due to the collision of oceanic islands/plateaus and, further on, the collision of the SLT with the NLT. Furthermore, the change from ca. 265–255 Ma alkaline magmatism to ca. 240–200 Ma calc‐alkaline magmatism within the SLT may reflect the geodynamic transition from lithospheric extension to Andean-style orogenesis. Therefore, we propose that subduction initiation of the Neo-Tethys oceanic lithosphere in the Tibetan Plateau resulted from the southward transference of the Sumdo Paleo-Tethys subduction zone, involving the collision of oceanic islands/plateaus and, subsequently, the collision of the SLT with the NLT. Additionally, the geological records of the Tethyan orogenic system suggest that the subduction initiation of the Neo-Tethys oceanic lithosphere is a uniform response to the collision between Cimmeria and Eurasia.
CRIS-Team Scopus Importer:2022-05-06
Keywords: Lhasa Terrane; Neo-Tethys; Plate tectonics; Subduction initiation; Subduction transference

Subduction of the oceanic Hikurangi Plateau and its impact on the Kermadec arc - Timm, Christian; Davy, Brian; Haase, Karsten; Hoernle, Kaj; Graham, Ian; De Ronde, Cornel; Woodhead, Jon; Bassett, Dan; Hauff, Folkmar; Mortimer, Nick; Seebeck, H.; Wysoczanski, Richard; et al. (Nature Communications, 2014)

Subglacial bedrock welding associated with glacial earthquakes - Bestmann, Michel; et al. (Journal of the Geological Society, 2006)

Sub log-scale heterogeneity of fine-grained sediments - Implications for effective permeability and top seal risking - Drews, Michael; Aplin, Andrew; Kurtev, Kuncho; Ma, Jingsheng (2nd International Fault and Top Seals Conference: From Pore to Basin Scale, 2009)

Submarine palaeoenvironments during Emeishan flood basalt volcanism, SW China: Implications for plume-lithosphere interaction during the Capitanian, Middle Permian ('end Guadalupian') extinction event - Jerram, Dougal A.; Widdowson, Mike; Wignall, Paul B.; Sun, Yadong; Lai, Xulong; Bond, David P. G.; Torsvik, Trond H. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2016)
Keywords: Extinction; Large igneous province; Plume; Submarine volcanism

Sub-Milankovitch paleoclimatic and paleoenvironmental variability in East Africa recorded by Pleistocene lacustrine sediments from Olduvai Gorge, Tanzania - Colcord, Devon E.; Shilling, Andrea M.; Sauer, Peter E.; Freeman, Katherine H.; Njau, Jackson K.; Stanistreet, Ian G.; Stollhofen, Harald; Schick, Kathy D.; Toth, Nicholas; Brassell, Simon C. (Palaeogeography, Palaeoclimatology, Palaeoecology, 2018)
Over the past century, numerous discoveries throughout East Africa have advanced our understanding of hominin evolution and provided substantive evidence that climatic and environmental variability played a critical role in evolutionary developments. Stratigraphic records with high temporal resolution aid in testing evolutionary hypotheses that invoke changes in climate and environment at various timescales as drivers of hominin evolution. Olduvai Gorge, Tanzania has a rich history of hominin fossil discoveries from its 2.0 Ma sedimentary sequence, which includes multiple deep lake intervals. In 2014, the Olduvai Gorge Coring Project (OGCP) recovered a sequence of sediment cores that provide an extensive record of the Pleistocene sedimentary history, including paleolacustrine systems in this area. With>94% core recovery, these cores are ideally suited for high resolution analyses of organic geochemical proxies and provide an exceptional opportunity to build on previously published outcrop-based paleoenvironmental data from Olduvai. The OGCP core 2A section between 76.6 and 86.9m depth is considered as a time-stratigraphic equivalent of strata that host the hominin fossils OH24 and OH56 at the Olduvai DK archaeological site. This depositional interval age-bracketed between 1.88 Ma (Bed I Basalt) and 1.85 Ma (Tuff IB) was sampled for organic geochemical analyses. The carbon isotopic composition of organic matter (δ13CTOC) from this section varies between values representative of more forested and open grassland ecosystems over 21 kyr. This observation is consistent with the Milankovitch precession cycle driving the availability of water, which was previously observed in lower resolution studies of outcrop samples. Complementary organic geochemical proxies provide further evidence of these shifts in environmental conditions and record sub-Milankovitch scale changes superimposed on the precession cycle. This suggests the occurrence of short-term fluctuations in the environments inhabited by hominins, which opens new lines of investigation on how environmental scenarios may affect particular evolutionary mechanisms that drove various evolutionary responses.
Keywords: Compound-specific isotope analysis; n-Alkane; Sediment core

Subsurface Fe (II) affects concentrations of dissolved O2 in streamwater - Parra-Suarez, Silvia; Wild, Romy; Gilfedder, Benjamin S.; Geist, Juergen; Barth, Johannes; Frei, Sven; Peiffer, Stefan (Water Research, 2025)
The interface between groundwater and surface water is a critical zone influencing ecohydrological and biogeochemical cycles within surface water ecosystems. It is characterized by complex redox gradients, with groundwater-mediated inflow of reduced substances affecting the oxygen budget of stream water. In this study, we have experimentally simulated the inflow of Fe(II)-rich groundwater into the open stream water of a flume system to quantify its effect on dissolved oxygen concentration in both the stream water and the hyporheic zone. The experimental setup consisted of 12 flumes, half used for input of groundwater augmented with Fe(II), while the other half served as a control. We studied the effects of coarse (6% fine sediment content) sediment vs. fine (28 % fine sediment content) sediment as well as and moderate (3 L s-1) vs. low (0.5 L s-1) flow rate in a fully-crossed, 3-way-replicated design. Weekly sampling campaigns were performed to analyze Fe(II), Fe(III), DOC, and dissolved oxygen (DO) concentrations in the pore water (hyporheic zone) and in the open water over five consecutive weeks. Our results indicate that Fe(II) inflow substantially decreased DO concentrations in both the pore and open waters. Oxygen uptake rates increased from 7.4 up to 8.6 g O2 m-2 d-1 at a moderate flow rate and from 1.7 to 1.9 g O2 m-2 d-1 at a low flow rate. This corresponds to a contribution of the Fe(II) input to the overall oxygen uptake rate in the flumes of 21 and 17%, respectively. Treatment with FeCl2 also led to a substantial increase in DOC from ∼ 55 mg L-1 in the control flumes to > 60 mg L-1 suggesting a linkage between Fe(II) mobilization and the occurrence of DOC. In conclusion, this study highlights the need to consider the effects of hyporheic and riparian redox processes and subsequent inflow of Fe(II) into streams on the oxygen budget and the health of stream ecosystems.
CRIS-Team Scopus Importer:2025-03-21
Keywords: Dissolved organic carbon; Dissolved oxygen; Ferrous iron; Hyporheic zone; Oxygen uptake rate; Redox potential

Subsurface granites in the Franconian Basin as the source of enhanced geothermal gradients: a key study from gravity and thermal modeling of the Bayreuth Granite - de Wall, Helga; Schaarschmidt, Anna; Kämmlein, Marion; Gabriel, Gerald; Bestmann, Michel; Scharfenberg, Lars (International Journal of Earth Sciences, 2019)
The Franconian Basin in NE Bavaria is a region of gravity low between the Bohemian Massif in the east and the Kraichgau Terrane in the west. Borehole measurements have identified the northern part of the Franconian Basin as a regional geothermal anomaly and new heat flow calculations give values of > 100 mW/m2. Distinct negative Bouguer anomalies observed in this basin are modeled as granitic intrusions in the Saxothuringian basement that underlies the Permo-Mesozoic units. The interpretation of gravity gradients, in combination with the filtering of gravity data, gives the possible depth constraints of the intrusive bodies. The resulting depths were cross-checked using microstructural studies of quartz veins in the basement rocks (at > 1341 m depth). The quartz shows structures typical for low-temperature plasticity and we infer a deformation temperature of ca. 300 °C. This indicates a considerable pre-Permian uplift of at least 7 km for parts of the Saxothuringian basement and supports depth estimates from gravity data. The heat supply of granitic intrusions by radiogenic decay is modeled considering several scenarios for the geological conditions recovered by the Obernsees borehole (model for conductive heat transfer). The 1390 m-deep drillhole is in a marginal position to the most-pronounced negative Bouguer anomaly. It could be shown that the Saxothuringian basement, including heat-producing granites (heat production rates: 4–6 μW/m3), covered by the insulating sedimentary rocks (1.35 km of Permian to Lower Jurassic units), can account for the enhanced geothermal gradient (38 °C/km) that were measured in the borehole.
CRIS-Team Scopus Importer:2019-07-09
Keywords: Gravity anomalies; Quartz microfabric; Radiogenic heat; Thermal modeling; Variscan granites

Subsurface Microbial Colonization at Mineral-Filled Veins in 2-Billion-Year-Old Mafic Rock from the Bushveld Igneous Complex, South Africa - Suzuki, Yohey; Webb, Susan J.; Kouduka, Mariko; Kobayashi, Hanae; Castillo, Julio; Kallmeyer, Jens; Moganedi, Kgabo; Allwright, Amy J.; Klemd, Reiner; Roelofse, Frederick; Mapiloko, Mabatho; Hill, Stuart J.; et al. (Microbial Ecology, 2024)
Recent advances in subsurface microbiology have demonstrated the habitability of multi-million-year-old igneous rocks, despite the scarce energy supply from rock-water interactions. Given the minimal evolution coupled with exceedingly slow metabolic rates in subsurface ecosystems, spatiotemporally stable igneous rocks can sustain microbes over geological time scales. This study investigated a 2-billion-year-old mafic rock in the Bushveld Igneous Complex, South Africa, where ultradeep drilling is being executed by the International Continental Scientific Drilling Program (ICDP). New procedures were successfully developed to simultaneously detect indigenous and contaminant microbial cells in a drill core sample. Precision rock sectioning coupled with infrared, fluorescence, and electron microscopy imaging of the rock section with submicron resolution revealed microbial colonization in veins filled with clay minerals. The entry and exit of microbial cells in the veins are severely limited by tight packing with clay minerals, the formation of which supplies energy sources for long-term habitability. Further microbiological characterization of drilled rock cores from the Bushveld Igneous Complex will expand the understanding of microbial evolution in deep igneous rocks over 2 billion years.
CRIS-Team Scopus Importer:2024-10-11
Keywords: Bushveld Drilling Project (BVDP); Deep biosphere; Life detection; Rock-hosted life; Subsurface microbes

Subsurface thermal conductivity assessment in Calabria (southern Italy): a regional case study - Di Sipio, Eloisa; Galgaro, Antonio; Destro, Elisa; Teza, Giordano; Chiesa, Sergio; Giaretta, Aurelio; Manzella, Adele (Environmental Earth Sciences, 2014)
Keywords: Shallow geothermal energy; Thermal conductivity; GIS; Geological formations; Southern Italy

Suitability of Screened Monitoring Wells for Temperature Measurements Regarding Large-Scale Geothermal Collector Systems - Bertermann, David; Rammler, Mario (Geosciences, 2022)
Groundwater temperature (GWT) is usually measured using screened monitoring wells (MWs). The aim of this study was to investigate whether MWs are suitable for monitoring the effects of large-scale geothermal collector systems (LSCs) on GWT, focusing on possible vertical flows within the MWs due to both natural and forced convection. Comparative temperature depth profiles were therefore recorded over a period of nine months in both shallow MWs and in small-diameter, non-screened temperature monitoring stations (TMSs), each of which was installed in a single borehole. Particularly high temperature deviations were measured in MWs in the upper part of the water column where the GWT reached up to 1.8 K warmer than in the surrounding subsurface. These deviations correlate unambiguously with the prevailing positive thermal gradients and are caused by thermal convection. Where forced convection occurred, the GWT was measured to be up to 0.8 K colder. Potential temperature deviations must be considered when monitoring very shallow GWT as thermal gradients can be particularly high in these zones. For monitoring concepts of LSCs, a combination of MW and TMS is proposed for GWT measurements decoupled by the effects of convection and in order to enable further investigations such as pumping tests.
CRIS-Team Scopus Importer:2022-05-06
Keywords: convection; groundwater temperature; hydrogeology; large-scale geothermal collector (LSC); monitoring well; subsurface

Sulfur and He-Ar isotopic constraints on the origin of alkalic-type epithermal Au-Ag-Te deposits: Insights from the Golden Sunlight deposit, Montana, USA - Zhao, Gang; Zhai, Degao; Keith, Manuel; Voudouris, Panagiotis; Tombros, Stylianos; Zhang, Hongyu; Liu, Jiajun (Ore Geology Reviews, 2025)
Alkalic-type epithermal Au-Ag-Te deposits are economically significant but remain genetically controversial. Debates center on whether ore-forming fluids and sulfur are primarily magmatic or involve substantial contributions from meteoric water or crustal materials. The Golden Sunlight Au-Ag-Te deposit in southwest Montana, USA, is unusual because the mineralization is concentrated within and around the hydrothermal Mineral Hill breccia pipe, which is hosted in the lower Mesoproterozoic Belt Supergroup and is spatially and genetically associated with a Late Cretaceous alkaline to subalkaline porphyry system. The mineralization, which constitutes a gold reserve >100 t, occurs either as disseminated or as structurally controlled veins within faults and joints, predominantly in the sulfide-rich matrix of the breccia pipe, the latite porphyry, and in Proterozoic sedimentary rocks. Alteration in and around the breccia pipe is principally composed of quartz and sericite, and is associated with four discrete stages of hypogene mineralization, in which stage I, represented by a quartz-pyrite-precious metal assemblage, is the most critical and economic stage. Throughout these mineralization stages, pyrite plays a pivotal role in the formation and stabilization of Au-Ag-Te minerals, and its association with native Au and tellurides suggests that pyrite not only acted as a physical host for the Au-Ag-Te mineralization, but also provided a favorable chemical environment for mineralization. Here, we combine the S isotope composition of pyrite, determined in-situ and on separates from micro-drilling, with its noble gas isotope composition to constrain the S and fluid sources, and the evolution of ore fluids during magmatic-hydrothermal processes. The light δ34S values of pyrite from the different mineralization stages, ranging from −13.57 to +0.30 ‰, along with the presence of oxides in stage I, suggest that mineralization is originated from oxidized-alkaline magmatic-hydrothermal fluids. By contrast, pyrite from the surrounding sedimentary rocks yielded significantly heavier δ34S values (+3.73 to +10.95 ‰), indicating a limited contribution of S from the Proterozoic sedimentary rocks to the magmatic-hydrothermal fluids. The obtained pyrite He-Ar isotopic compositions, specifically the 3He/4He ratios that range from 0.23 to 1.01 Ra, revealed a mixing trend between mantle (up to 13 %) and crustal components, confirming the contribution of mantle-derived fluids to the shallow low-temperature ore system. Our study emphasizes that combined S and He-Ar isotope analyses of pyrite within a robust geological and mineralogical framework could constrain the sources of ore-forming fluids, provide insights into the processes of mineralizing events, and offer valuable clues for deep mineral exploration.
CRIS-Team Scopus Importer:2025-01-31
Keywords: Alkalic-type epithermal mineralization; Au-Ag telluride deposit; Golden Sunlight; He-Ar isotope; SIMS sulfur isotope

Superimposed structures, incremental strain and deformation path from field data to modelling: A case study from the Alpi Apuane metamorphic core complex (NW Tuscany, Italy). - Molli, G.; Köhn, Daniel; Allacorta, L.; Danese, L.; Zampelli, S.; Zazzeri, M. (Journal of Structural Geology, 2022)
In this study, superimposed folds and antitaxial strain fringes are investigated to unravel the deformation path of the core zones of the Alpi Apuane metamorphic complex (northwest Tuscany Italy). Detailed field mapping combined with microstructural analyses is used together with computer-modelling of a complex strain fringe system to disclose the main steps of the Alpi Apuane syn-metamorphic deformation history. A comparison between natural investigated fibres and those produced by paraffine wax experiments provides details of the relative core-object-fringe rotation allowing new insight on the growth kinematics of strain fringes. The results of our analyses show that our composite fringe system is characterized by a first set of fibres to be related with the main composite axial planar foliation of regional scale isoclinal non-cylindric folds. This first set of fibre fringes records a local non-coaxial strain with an absolute core-object rotation (relative to an external reference frame represented by the main foliation) of 140° and a calculated shear strain (γ) of about 4. The second set of fringes, developed after the tilting of the main foliation and the first fringe-set in a sub-vertical orientation, records a lower absolute rotation of the core-object (25°), a lower shear strain (γ) of about 1.4 and a coaxial strain associated with the vertical shortening. This part of the composite fringe system and the related structures may relate to the switch from the crustal scale contractional regime to the extensional one, which characterized the development of the inner northern Apennines orogen.
CRIS-Team Scopus Importer:2022-09-09
Keywords: Alpi Apuane; Modelling incremental strain; Northern Apennines; Strain fringes; Superimposed folds; Tectonics

Superplume mantle tracked isotopically the length of Africa from the Indian Ocean to the Red Sea - O'Connor, John; Jokat, Wilfried; Regelous, Marcel; Kuiper, Klaudia; Miggins, Dan P.; Koppers, Anthony A P (Nature Communications, 2019)
Seismological findings show a complex scenario of plume upwellings from a deep thermo-chemical anomaly (superplume) beneath the East African Rift System (EARS). It is unclear if these geophysical observations represent a true picture of the superplume and its influence on magmatism along the EARS. Thus, it is essential to find a geochemical tracer to establish where upwellings are connected to the deep-seated thermo-chemical anomaly. Here we identify a unique non-volatile superplume isotopic signature ('C') in the youngest (after 10 Ma) phase of widespread EARS rift-related magmatism where it extends into the Indian Ocean and the Red Sea. This is the first sound evidence that the superplume influences the EARS far from the low seismic velocities in the magma-rich northern half. Our finding shows for the first time that superplume mantle exists beneath the rift the length of Africa from the Red Sea to the Indian Ocean offshore southern Mozambique.

Surface water freshening and high-latitude river discharge in the Eocene North Sea. - Zacke, Anne; Voigt, Silke; Joachimski, Michael; Gale, Andrew S.; Ward, David J.; Tuetken, Thomas (Journal of the Geological Society, 2009)
A shark-tooth apatite δ18O record of the early Palaeogene North Sea reflects changes in regional hydrography by showing variable temperatures and salinities. A 2-4 Ma period in the early Eocene was particularly influenced by substantial surface-water freshening, indicated by a 3-4‰ reduction of δ18O values. The magnitude of the δ18O decrease indicates a depletion in 18O of surface waters by 2-3‰ relative to Eocene mean ocean water. This value is lower than that of coeval lakes reconstructed from freshwater gastropod δ18O values from the Paris Basin, suggesting that large rivers with high-latitude catchment areas drained into the North Sea. The period of surface-water freshening began close to the Palaeocene - Eocene thermal maximum, when relative sea-level fall, tectonic uplift and basaltic volcanism caused a temporary isolation of the North Sea. North Atlantic and North Sea surface waters became reconnected during a series of early Eocene transgressions. © 2009 Geological Society of London.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.LG.surfac

Survivorship dynamics of the flora of Devonian Angarida - Dowding, Elizabeth; Akulov, Nikolay Ivanovich; Mashchuk, Irina Mikhailovna (Proceedings of the Royal Society of London, Series B: Biological Sciences, 2023)
Devonian plants in Siberia present protracted pioneer succession. Research into the survivorship dynamics of early plant communities upon the palaeocontinent Angarida have demonstrated that transgression and volcanogenic nutrient influx were key to the survival of colonizing plants. Taxic proportions show that migrating taxa entered Angarida from the southwest, Kuznetsk and Minusinsk basins, dispersing across the continent in waves through central areas northwards. The patterns of dispersal are consistent throughout the Devonian. Increased nutrient load from the active pulses of the Viluy-Yakutsk Large Igneous Province, biogeomorphic ecosystem engineering and the increased biomass of Angaridan plants are assisted by Late Devonian transgression. These cumulative factors can be linked to the Late Devonian marine extinctions observed in Siberia.
CRIS-Team Scopus Importer:2023-01-20
Keywords: Devonian; Large Igneous Province; phytogeography; Siberia

Susceptibility analysis for slides and rockfall: an example from the Northern Calcareous Alps (Vorarlberg, Austria) - Ruff, Michael; Rohn, Joachim (Environmental Geology, 2008)
In this paper a tool for semi-quantitative susceptibility assessment at a regional scale is presented which is applicable at areas with complex geological setting. At a study area within the Northern Calcareous Alps geotechnical mappings were implemented into a Geographical Information System and analysed as grid data with a cell size of 25 m. The susceptibility to sliding and falling processes was considered according to five classes (very low, low, medium, high, very high). Susceptibility to sliding was analysed using an index method. The layers of lithology, bedding conditions, tectonic faults, slope angle, slope aspect, vegetation and erosion were combined iteratively. Dropout zones of rockfall material were determined with help of a Digital Elevation Model. The movement of rolling rock samples was modelled by a cost analysis of all potential rockfall trajectories. These trajectories were also divided into five susceptibility classes. The susceptibility maps are presented in a general way to be used by communities and spatial planners. Conflict areas of susceptibility and landuse were located and can be presented destinctively. © 2007 Springer-Verlag.
UnivIS-Import:2015-03-09:Pub.2008.nat.dgeo.IGM.profes_3.suscep
Keywords: Austria; GIS; Landslides; Northern Calcareous Alps; Rockfall; Susceptibility; Vorarlberg

Sweet home Lophelia: A multicolour journey into the microcosm of bioeroders from the Propeller Mound, Porcupine Seabight - Beuck, Lydia; Schulbert, Christian; Freiwald, André (Erlanger Geologische Abhandlungen, Sonderband 4, 2003)
Bioerosion (Neumann, 1966) describes the disintegration processes of hard substrates such as calcareous skeletons through the activity of organisms by mechanical removal of carbonates (bioabrasion) or by chemical dissolution (biocorrosion) and is a well-known process in the alteration of shallow-water coral reefs. Endolithic organisms live within the skeleton either for protection or nourishment. The different bioerosional processes result in a destruction of reefal frameworks. The study of these ichnocoenoses (endolithic trace communities) allows to reconstruct (paleo-)environments and applicable depth zonations of neritic environmental settings through the Phanerozoic era. The ichnodiversity in the course of time also forms integrals for the understanding of the longevity and fossilisation potential and will lead to the definition of ecologic "health conditions" of deep-water corals for a rapid large-scale assessment. In this presentation, the prevalent aphotic bioeroder community found within the skeleton of the cosmopolitan coral Lophelia pertusa from the Propeller Mound, Porcupine Seabight, sampled in 629 to 780 m water depth, is demonstrated using the vacuum-cast-embedding method with subsequent SEM analysis: Shown are coloured SEM pictures of resin casts with an accentuation of different boring organism group
Keywords: Lopheloa; Bioerosion; Propeller Mound; Porcupine Seabight

Synchronous Monitoring of Cement Hydration and Polymer Film Formation Using 1H-Time-Domain-NMR with T2Time-Weighted T1Time Evaluation: A Nondestructive Practicable Benchtop Method - Jansen, Daniel; Ectors, Dominique; Kong, Xiangming; Schmidtke, Christian; Deschner, Florian; Pakusch, Joachim; Jahns, Ekkehard; Neubauer, Jürgen (ACS Omega, 2021)
The interactions between latex and cement are still not completely understood. In this work, we would like to address the temporal changes in cement hardening and latex film formation. For this reason, the hydration process and the film formation were simultaneously monitored. This scientific issue is even more challenging as a nondestructive quantitative analysis of the film formation process is not available yet. Here, we report on simultaneous monitoring of the latex film formation and the phase development in cementitious systems via 1H-time-domain-NMR for the first time. The obtained results were validated using classical analytical methods, such as in situ X-ray diffraction, X-ray fluorescence (Rietveld analysis), and confocal laser scanning microscopy.
CRIS-Team Scopus Importer:2021-04-16

Synchronous motion of the Easter mantle plume and the East Pacific Rise - O’Connor, John M.; Regelous, Marcel; Haase, Karsten; Hemond, Christophe; Koppers, Anthony A.P.; Miggins, Daniel P.; Heaton, Daniel E. (Nature Communications, 2024)
The Easter mantle plume has produced one of the longest hotspot tracks in the Pacific Ocean. While previous studies have focused on the eastern side extending across the Nazca Plate, we use 40Ar/39Ar isotopic and geochemical data to investigate the less explored western side around the Easter Microplate. We propose a dynamic model in which a deeper (600 km-depth), less buoyant mantle exerts a westward force on the East Pacific Rise (EPR), while a more buoyant plume region drives Easter hotspot volcanism and a localised acceleration in seafloor spreading. Our findings suggest that the Easter hotspot is the more focused surface expression of the most buoyant region of a vast, deep-seated mantle plume extending from the Pacific Large Low Shear Velocity Province (LLSVP). This challenges the traditional view of hotspots as isolated phenomena and suggests they are part of broader LLSVP-related mantle structures. Our results imply a more intricate, large-scale relationship between hotspots, mantle plumes, spreading ridges, and mantle dynamics.
CRIS-Team Scopus Importer:2024-11-29

Syndepositional Tectonic Controls and Palaeo-Topography of a Permian Tight Gas Reservoir in NW Germany - Vackiner, Anna Alexandra; Stollhofen, Harald; Antrett, Philipp; Back, Stefan; Kukla, Peter; Bärle, Claudia (Journal of Petroleum Geology, 2011)
A combined tectonic-stratigraphic interpretation of three-dimensional seismic reflection, wireline log and core data is presented in this study focussing on a tight gas field in East Frisia, NW Germany. Upper Rotliegend reservoir rocks in the study area are of fluvio-aeolian origin and include dune, minor sandflat and wet to dry interdune deposits. Source rocks are Westphalian coals and a top seal is provided by Zechstein evaporites. Detailed analyses of palaeo-topography, fault activity and accommodation space development for strata of Permian age (Rotliegend and Zechstein groups) indicate that local depocentres developed within small-scale fault-controlled transtensional sub-basins. Synsedimentary half-graben development and fault activity occurred during Upper Rotliegend II (mainly Elbe Subgroup) deposition. Many Upper Rotliegend structures were then reactivated during the Triassic, Jurassic and Cretaceous, often with enhanced offsets and increased lateral extent. As a consequence, Rotliegend structures and stratigraphy were significantly displaced resulting in the relocation of former Rotliegend depocentres and associated tight gas reservoir facies. This tectonic overprint hampers the prediction of potential Rotliegend reservoirs, and shows that palaeo-environmental restoration is required in areas which have undergone multi-phase deformation histories. Exploration strategies in the study area have favoured drilling locations in present-day structural highs. This study suggests that sediment traps were controlled by synsedimentary Upper Rotliegend II to Zechstein palaeo-topography, defining a new concept for future tight gas exploration. © 2011 The Authors. Journal of Petroleum Geology © 2011 Scientific Press Ltd.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LG.syndep
Keywords: Isopach map analysis; Palaeo-topography; Rotliegend; Southern Permian Basin; Tectonics and sedimentation; Tight gas

Syn-kinematic inversion in an intracontinental extensional field? A structural analysis of the Waterberg Thrust, northern Namibia - Granath, James; Wanke, Ansgar; Stollhofen, Harald (Journal of Structural Geology, 2022)
A structural analysis of a key area along the Waterberg Thrust in northern Namibia clarifies its geometric and timing relationships to the deposition of rift-related Karoo sediments. The fault brings late Precambrian crystalline rocks up against Permo-Triassic and Lower Jurassic Karoo clastic sediments of the Waterberg Basin between two of the major regional basement-rooted lineaments that cut across northern Namibia, using those subparallel lineaments as transfer faults. Detailed mapping and kinematic analysis have been used to construct and restore several sections across the thrust that put initiation of reverse offset as a thrust in Triassic time. Thinskinned footwall deformation created several unconformities in a footwall cutoff system. The unconformities were subsequently folded during continued motion on the fault. Various dating techniques constrain the initiation of contractional deformation to the Triassic to Jurassic (Karoo time) with episodic progression during the development of the basin, followed by major further reactivation during regional uplift related to the Atlantic margin rifting and subsequent continental breakup. This early phase is linked in time so closely to the basin development that we attribute the driver of inversion to be kinematically linked to the displacement field of Neoproterozoic basement blocks themselves. Hence, we term this relationship as ‘syn-kinematic’ to distinguish it from wholly external, superimposed driving mechanisms (‘allo-kinematic’).<br
Keywords: Waterberg thrust; Karoo tectonics; Namibia geology; Inversion tectonics; Intraplate tectonics

Synsedimentary faults and amalgamated unconformities : Insights from 3D-seismic and core analysis of the Lower Triassic Middle Buntsandstein, Ems Trough, north-western Germany. - Radies, Dirk; Stollhofen, Harald; Hollmann, Gregor; Kukla, Peter (International Journal of Earth Sciences, 2005)
The Late Permian/Early Triassic succession of the Central European Basin (CEB) was repeatedly affected by the tectonic pulses associated with the earliest phases of Tethyan and Arctic-North Atlantic rifting. Effects of the differential tectonic subsidence are particularly well recorded by unconformities, which form widespread sequence boundaries. Such unconformities are most obvious in areas occupied by fault-controlled intra-basinal highs (swells). In that areas, stratigraphic loss may comprise entire Lower and Middle Buntsandstein formations and in places remnant Middle Buntsandstein successions directly rest on Permian strata. Analysis of 3D-seismic data and well logs combined with high-resolution sedimentological logging of drillcores at the western margin of the Ems Trough (NW Germany) reveals details of synsedimentary tectonic control on sequence development. Early Triassic extensional faulting of basement blocks provided stepwise addition of accommodation space for continental sequences by growth faulting along north-south oriented fault zones blocks on the flanks of the East Netherlands High. This process is most evident during the development of the Hardegsen Unconformity, which is characterised by an amalgamation of succeeding unconformity surfaces in areas of structurally controlled intrabasinal highs. © Springer-Verlag 2005.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LG.synsed
Keywords: Buntsandstein; Continental sequences; Early Triassic; Synsedimentary tectonics; Unconformities

Syn-tectonic generation of potential reservoir-sandstones in arid low-gradient depositional systems - the Lower Triassic Middle Buntsandstein at the western margin of the Ems Trough, NW Germany. - Radies, Dirk; Stollhofen, Harald; Hollmann, Gregor; Kukla, Peter (Oil Gas-European Magazine, 2005)
Effects of the earliest Tethyan and Arctic-North Atlantic rifting phases on the Early Triassic succession of the Central European Basin are particularly well recorded by unconformities, which form widespread sequence boundaries. Stratigraphic loss related to these unconformities may comprise entire Lower and Middle Buntsandstein formations most obviously developed in areas occupied by fault-controlled intra-basinal highs (swells). Analysis of 3D-seismic data and well logs combined with high-resolution sedimentological logging of drillcores at the western margin of the Ems Trough (NW Germany) reveals details of synsedimentary tectonic control on sequence development. Early Triassic extensional faulting of basement blocks provided stepwise addition of accommodation for continental sequences by growth faulting along north-south trending fault zones blocks on the flanks of the East Netherlands High. This process is most evident during the development of the Hardegsen Unconformity, which is characterized by an amalgamation of succeeding unconformity surfaces in areas of structurally controlled intrabasinal highs. The mainly aeolian toplaya-type sedimentary facies of the Middle Buntsandstein succession suggests very low intrabasinal relief and implies a constant reworking and levelling of the palaeo-surface. Consequently, the development and preservation of stratigraphic units is primarily determined by the potential accommodation provided by synsedimentary tectonics. © 2005 URBAN-VERLAG Hamburg/Wien GmbH.
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LG.syntec

Syn-tectonic sequence generation in low gradient desert margin systems - the Lower Triassic Middle Buntsandstein at the western margin of the Ems Basin, NW Germany. - Radies, Dirk; Stollhofen, Harald; Hollmann, Gregor; Kukla, Peter (DGMK Tagungsbericht, 2005)
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LG.syntec_3

Synthese und Rietveldverfeinerung der Gehlenit-Mischkristallreihe - Schmid, Markus; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; Göbbels, Matthias (European Journal of Mineralogy, 2003)
UnivIS-Import:2015-03-09:Pub.2003.nat.dgeo.IGM.LM.synthe

Synthese von Alinit, Hauptbestandteil im Alinitzement - Neubauer, Jürgen; Oberste-Padtberg, Rüdiger; Pöllmann, Herbert (European Journal of Mineralogy, 1991)
UnivIS-Import:2015-03-05:Pub.1991.nat.dgeo.IGM.LM.synthe

Synthese von Fe3+-substitutierten Tricalciumaluminaten und Auswirkungen auf deren Hydratationsverhalten - Kemethmüller, Stefan; Neubauer, Jürgen; Götz-Neunhoeffer, Friedlinde (2001)
UnivIS-Import:2015-03-09:Pub.2001.nat.dgeo.IGM.LM.synthe

Synthesis and characterization of cellular apatite-whitlockite composites for bone substitution - Götz-Neunhoeffer, Friedlinde; Enderle, Ralph; Göbbels, Matthias (Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften, 2005)
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LM.synthe_2

Synthesis and characterization of chloride bearing silico - sulfate apatite - Neubauer, Jürgen; Pöllmann, Herbert (Neues Jahrbuch für Mineralogie-Abhandlungen, 1992)
UnivIS-Import:2015-03-05:Pub.1992.nat.dgeo.IGM.LM.synthe

Synthesis and mineralogical characterization of calcium ferrate hydrates and their application as reservoir minerals in waste dumps - Götz-Neunhoeffer, Friedlinde; Pöllmann, Herbert (Applied Mineralogy in Research, Economy, Technology, Ecology and Culture, 2000)
UnivIS-Import:2015-03-09:Pub.2000.nat.dgeo.IGM.LM.synthe
Keywords: Angewandte Mineralogie; Applied Mineralogy

Synthesis and Rietveld refinement of Ferri-Gehlenite solid solution series - Schmid, Markus; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; Göbbels, Matthias (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 2005)
UnivIS-Import:2015-03-09:Pub.2005.nat.dgeo.IGM.LM.synthe

Synthesis and Structure Refinement of Zinc-Doped Beta-Tricalcium Phosphate Powders - Kannan, Surekka; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; da Fonte Ferreira, José Maria (Journal of the American Ceramic Society, 2009)
Zinc substituted β-tricalcium phosphate [β-Ca3(PO 4)2] was formed by substituting a zinc precursor in calcium-deficient apatite through aqueous precipitation technique. Heat treatment at 1000°C led to the formation of well crystalline β-Ca 3(PO4). Refinement technique was used to determine the influence of incorporated zinc in the β-Ca3(PO4) structure. The structural data for all the four different zinc substituted β-Ca3(PO4) ranging from 0-9 mol% of zinc investigated in the present study confirmed the rhombohedral structure of β-Ca 3(PO4) in the hexagonal setting (space group R3c). The incorporation of lower sized Zn2+ (0.745 Å for sixfold coordination with O) at the higher sized Ca2+ (1.00 Å for sixfold coordination with O) site in the β-Ca3(PO4) structure led to the contraction of unit cell parameters. The added zinc prefers to occupy the Ca(5) site of β-Ca3(PO4) structure. © 2009 The American Ceramic Society.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.LM.synthe

Synthesis an structural characterization of strontium- and magnesium-co-substituted beta-tricalcium phosphate - Kannan, Surekka; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen; Pina, Sandra; Torres, Paula M. C.; da Fonte Ferreira, José Maria (Acta Biomaterialia, 2010)
The synthesis of five different Sr2+- and Mg2+-co-substituted β-tricalcium phosphate (β-TCP) has been obtained by heating the calcium-deficient apatites above 800 °C. With the investigated concentrations of Sr2+ and Mg2+ from the present study, no additional phases other than β-TCP have been detected. The synthesized powders have been characterized by X-ray diffraction, Fourier transform infrared spectrometry, elemental analysis and Rietveld refinement studies. The co-substitution of Sr2+ and Mg2+ in the β-TCP has resulted in the formation of crystalline β-TCP at hexagonal setting (space group R3c). The reduction of lattice a- and c-axis parameters with the combined substitution of Sr2+ and Mg2+ in the β-TCP has been found evident from the present results. Sr2+ has been found occupying the Ca(1,2,3,4) sites and Mg2+ was found at the sixfold coordinated Ca(5) site of β-TCP structure. © 2009 Acta Materialia Inc.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LM.synthe
Keywords: β-TCP; Co-substitution; Magnesium; Rietveld refinement; Strontium

Synthesis, characterization, antibacterial properties, and in vitro studies of selenium and strontium co-substituted hydroxyapatite - Maqbool, Muhammad; Nawaz, Qaisar; Ur Rehman, Muhammad Atiq; Cresswell, Mark; Jackson, Phil; Hurle, Katrin; Detsch, Rainer; Goldmann, Wolfgang; Shah, Asma Tufail; Boccaccini, Aldo R. (International Journal of Molecular Sciences, 2021)
In this study, as a measure to enhance the antimicrobial activity of biomaterials, the selenium ions have been substituted into hydroxyapatite (HA) at different concentration levels. To balance the potential cytotoxic effects of selenite ions (SeO32−) in HA, strontium (Sr2+) was co-substituted at the same concentration. Selenium and strontium-substituted hydroxyapatites (Se-Sr-HA) at equal molar ratios of x Se/(Se + P) and x Sr/(Sr + Ca) at (x = 0, 0.01, 0.03, 0.05, 0.1, and 0.2) were synthesized via the wet precipitation route and sintered at 900 °C. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and cell viability were studied. Xray diffraction verified the phase purity and confirmed the substitution of selenium and strontium ions. Acellular in vitro bioactivity tests revealed that Se-Sr-HA was highly bioactive compared to pure HA. Se-Sr-HA samples showed excellent antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus carnosus) bacterial strains. In vitro cell–material interaction, using human osteosarcoma cells MG-63 studied by WST-8 assay, showed that Se-HA has a cytotoxic effect; however, the co-substitution of strontium in Se-HA offsets the negative impact of selenium and enhanced the biological properties of HA. Hence, the prepared samples are a suitable choice for antibacterial coatings and bone filler applications.
CRIS-Team Scopus Importer:2021-04-30
Keywords: Antibacterial; Co-substituted hydroxyapatite; Cytocompatibility; Selenium; Strontium

Synthesis of Camphor-Derived Bis(pyrazolylpyridine) Rhodium(III) Complexes: Structure-Reactivity Relationships and Biological Activity - Petrovic, Angelina; Milutinovic, Milan M.; Petri, Edward T.; Zivanovic, Marko; Milivojevic, Nevena; Puchta, Ralph; Scheurer, Andreas; Korzekwa, Jana; Klisuric, Olivera R.; Bogojeski, Jovana (Inorganic Chemistry, 2019)
Two novel rhodium(III) complexes, namely, [Rh III (X)Cl 3 ] (X = 2 2,6-bis((4S,7R)-7,8,8-trimethyl-4,5,6,7-tetrahydro-1H-4,7-methanoindazol-3-yl)pyridine or 2,6-bis((4S,7R)-1,7,8,8-tetramethyl-4,5,6,7-tetrahydro-1H-4,7-methanoindazol-3-yl)pyridine), were synthesized from camphor derivatives of a bis(pyrazolylpyridine), tridentate nitrogen-donor chelate system, giving [Rh III (H 2 L∗)Cl 3 ] (1a) and [Rh III (Me 2 L∗)Cl 3 ] (1b). A rhodium(III) terpyridine (terpy) ligand complex, [Rh III (terpy)Cl 3 ] (1c), was also synthesized. By single-crystal X-ray analysis, 1b crystallizes in an orthorhombic P2 1 2 1 2 1 system, with two molecules in the asymmetric unit. Tridentate coordination by the N,N,N-donor localizes the central nitrogen atom close to the rhodium(III) center. Compounds 1a and 1b were reactive toward l-methionine (l-Met), guanosine-5′-monophosphate (5′-GMP), and glutathione (GSH), with an order of reactivity of 5′-GMP > GSH > l-Met. The order of reactivity of the Rh III complexes was: 1b> 1a > 1c. The Rh III complexes showed affinity for calf thymus DNA and bovine serum albumin by UV-vis and emission spectral studies. Furthermore, 1b showed significant in vitro cytotoxicity against human epithelial colorectal carcinoma cells. Since the Rh III complexes have similar coordination modes, stability differences were evaluated by density functional theory (DFT) calculations (B3LYP(CPCM)/LANL2DZp). With (H 2 L∗) and (terpy) as model ligands, DFT calculations suggest that both tridentate ligand systems have similar stability. In addition, molecular docking suggests that all test compounds have affinity for the minor groove of DNA, while 1b and 1c have potential for DNA intercalation.
CRIS-Team Scopus Importer:2019-05-09

Synthesis of Eu-doped SrAl2O4 nanophosphors by CO2 laser vaporization - Zollfrank, Cordt; Gruber, Sabine; Batentschuk, Miroslaw; Osvet, Andres; Götz-Neunhoeffer, Friedlinde; Dittrich, Sebastian; Grabow, Janet; Kurland, Heinz-Dieter; Müller, Frank A. (Acta Materialia, 2013)
A new method of synthesizing spherical nanoparticles with photoluminescent spinel structures using a CO2 laser co-vaporization technique (CoLAVA) is presented. The method applies homogeneous mixtures of oxidic precursors such as Al2O3, SrO and Eu2O 3 and allows the fabrication of quantities exceeding 10 g h -1. During the CoLAVA process, the educt oxides are reacted by a gas phase condensation yielding amorphous spherical particles with diameters ranging from 10 to 100 nm. The as-prepared materials exhibit red emission at 625 nm (1.98 eV) due to the incorporated Eu3+. Temperature treatment up to 1200 C under a reducing atmosphere yielded crystalline particles of the same size, which were slightly sintered. These particles consisted of >90 wt.% SrAl2O4 with minor fractions of Sr3Al 2O6 and SrCO3. The amount of the SrAl 2O4 spinel increased with increasing temperature, whereas the accompanying phases were decreased. A strong green emission centered at 525 nm (2.36 eV) detected at RT was observed at an onset temperature of 900 C, which is due to the presence of Eu2+ in the crystal lattice of SrAl 2O4. The red emission was not observed at higher annealing temperatures. The CoLAVA method represents a fast and facile route for the fabrication of nano- to microstructured phosphor materials for a variety of engineering applications. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LM.synthe
Keywords: Laser vaporization; Nanoparticles; Photoluminescence

Synthesis of monocrystalline Ca3SiO5 using the optical floating zone method - Naber, Christoph; Götz-Neunhoeffer, Friedlinde; Göbbels, Matthias; Rößler, Christiane; Neubauer, Jürgen (Cement and Concrete Research, 2016)
Alite (CaSiO/CS with low concentrations of foreign ions) is the main constituent of Ordinary Portland Cement. Normally it forms during sintering but with quite low crystal sizes (ca. 30 μm). For experiments on alite hydration behavior monocrystalline grains are required. Due to its incongruent melting behavior and its thermodynamic instability below 1250 °C it is very challenging to obtain large alite single crystals. In the present study, the floating zone method was used for annealing polycrystalline rods of monoclinic and triclinic CS just below the melting point of the phase. Large monocrystalline grains (> 500 μm) of the monoclinic (Al, Mg-doped) and triclinic polymorphs could successfully be obtained. Monocrystallinity was demonstrated by electron backscatter diffraction (EBSD). The chemical composition regarding incorporation of foreign ions and thus the resulting crystallographic modification of the CS can easily be adjusted. Chemical homogeneity of the synthesized monocrystalline grains was proven by electron probe microanalysis (EPMA).
Keywords: Ca3SiO5 (D); Crystal size (B); Floating zone method; SEM (B)

Syn-vivo bioerosion of Nautilus by endo- and epilithic foraminiferans (New Caledonia and Vanuatu) - Seuß, Barbara; Wisshak, Max; Mapes, Royal H.; Landman, Neil (PLoS ONE, 2015)
A variety of syn-vivo bioerosion traces produced by foraminiferans is recorded in shells of Nautilus sampled near New Caledonia and Vanuatu. These are two types of attachment scars of epilithic foraminiferans and two forms of previously undescribed microborings, a spiral-shaped and a dendritic one, both most likely being the work of endolithic 'naked' foraminiferans. Scanning electron microscopy of epoxy-resin casts of the latter revealed that these traces occur in clusters of up to many dozen individuals and potentially are substrate-specific. The foraminiferan traces are the sole signs of bioerosion in the studied Nautilus conchs, and neither traces of phototrophic nor other chemotrophic microendoliths were found. While the complete absence of photoautotrophic endoliths would be in good accordance with the life habit of Nautilus, which resides in aphotic deep marine environments and seeks shallower waters in the photic zone for feeding only during night-time, the absence of any microbial bioerosion may also be explained by an effective defence provided by the nautilid periostracum. Following this line of reasoning, the recorded foraminiferan bioerosion traces in turn would identify their trace makers as being specialized in their ability to penetrate the periostracum barrier and to bioerode the shell of modern Nautilus.
UnivIS-Import:2015-07-08:Pub.2015.nat.dgeo.IGM.LP.synviv

Synvulkanische Sedimentation in einem fluviatilen Ablagerungsraum: Das basale "Oberrotliegend" im permokarbonen Saar-Nahe-Becken - Stollhofen, Harald (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 1994)
Mächtige basaltisch-andesitische Laven und rhyolithisch-dazitische Tuffe wechsellagern in den Profilen des basalen "Oberrotliegend" mit fluviatilen Ablagerungen. Innerhalb eines durch die Leithorizonte Tuffserie I und II definierten Profilteils werden sowohl die während des beckeninternen Vulkanismus auftretenden Sedimentationsprozesse untersucht, als auch die Fazies und Architektur, die Förderorte und die Eruptionsmechanismen der Vulkanite diskutiert. Verbreitung, Fragmentierungsgrad und die Position der proximalen Faziesbereiche deuten an, daß die Hauptmasse der sauren Pyroklastika durch phreatoplinianische Eruptionen an Tuffringen (Tuffserie I) und durch den Kollaps von intrusiv/extrusiven Domen (Tuffserie II) während der Platznahme der Intrusionen von Donnersberg, Kuhkopf und Holbornerhof-Kuppel gefördert wurden. Andesitische Tuffe weisen meist deutlich höhere Nebengesteinsanteile auf und werden surtseyanischen Eruptionen von Maaren zugeordnet. Aufgrund der Horizontbeständigkeit der beteiligten Gesteinskörper wird angenommen, daß die basischen Laven des Donnersberg- und des Olsbrücken Lagers an Spalten eruptiert wurden, zumal Hinweise auf ausgeprägte Vulkanbauten fehlen. Während aktiver Eruptionsphasen wurde die Sedimentation maßgeblich durch beckeninterne Prozesse gesteuert. Von mehreren, teilweise zeitgleich aktiven Förderorten erfolgte die Eruption von Laven, Aschenfällen, Surges, heißen und kühlen Aschenströmen. Die während oder kurz nach den Eruptionen einsetzende Umlagerung großer Mengen lockeren und leicht erodierbaren pyroklastischen Materials wird durch Ablagerungen von Schichtfluten neben Schutt- und Schlammströmen repräsentiert. Während langer vulkanischer Ruhepausen dominierte im medialen und distalen Faziesbereich hingegen ein mäandrierendes Flußsystems, das siliziklastische Sedimente ablagerte. Hierbei wurde die Sedimentation insbesondere durch beckenexterne Prozesse gesteuert. Eine bevorzugte Erhaltung primärer pyroklastischer Ablagerungen erfolgte auf der ausgedehnten Überflutungsebene dieses nach Norden entwässernden, transversalen Flußsystems, wurde aber auch durch intensive synsedimentäre Tektonik kontrolliert.
Keywords: Intramontane basin; geological sections; Saxonian (Upper Rotliegend); lithofacies; fluvial sedimentation; siliciclastic sediments; eruptions; lavas basaltic-andesitic composition; tuffs; rhyolitic-dacitic composition; key beds; sedimentary cycle; explosive eruptions

Systematic and Temporal Geochemical Changes in the Upper Deccan Lavas: Implications for the Magma Plumbing System of Flood Basalt Provinces - Hoyer, Patrick; Haase, Karsten; Regelous, Marcel; Fluteau, F. (Geochemistry Geophysics Geosystems, 2023)
Large Igneous Provinces (LIPs) are unusual volcanic events in which massive amounts of melt (∼106 km3) erupt in relatively short time periods (<106 years). Most LIP magmas have undergone extensive fractional crystallization and crustal contamination, but the crustal magmatic plumbing systems and the processes triggering eruptions are poorly understood. We present new major and trace element and radiogenic isotope data for 43 individual lava flows from a continuous 1,200 m thick stratigraphic profile through the upper, most voluminous part of the Deccan LIP (Bushe to Mahabaleshwar Formations). Eruption rates for this section are constrained by published paleomagnetic directions and absolute U-Pb ages for zircons from weathered flow tops exposed in the profile. We find four magmatic sequences each lasting ∼104–∼105 years during which major and trace element compositions change systematically, followed by an abrupt change in geochemistry at the start of a new sequence. Within each sequence, the MgO content and proportion of crustal contamination decrease progressively, indicating a continuous replenishment of the associated magma reservoirs with less contaminated but more evolved melts. These geochemical signatures are best explained by repeated episodes of melt recharge, mixing, and eruption of variably evolved magmas originating from relatively small magma reservoir located in different crustal levels.
CRIS-Team Scopus Importer:2023-03-03
Keywords: intraplate processes; magma chamber processes; magma genesis and partial melting; major and trace element geochemistry; radiogenic isotope geochemistry

Systematic occurrences of malformed (teratological) acritarchs in the run-up of Early Palaeozoic δ13C isotope excursions - Munnecke, Axel; Delabroye, Aurélien; Servais, Thomas; Vandenbroucke, Thijs R.A.; Vecoli, Marco (Palaeogeography, Palaeoclimatology, Palaeoecology, 2012)
The Late Ordovician and Silurian are characterised by several strong, global positive δC excursions. Some of them exceed +5‰ and thus belong to the strongest perturbations of the carbon cycle in the Phanerozoic. The onset of the excursions is characterised by extinction and/or turnover events of several groups of marine invertebrates. The causal mechanisms of the carbon cycle perturbations, however, are still unknown and currently a matter of vigorous scientific debate. Our own investigations in the Hirnantian (latest Ordovician) have shown that the onset of the major δC excursion (HICE) is characterised by very high abundances of acritarchs showing abnormal, teratological forms. A critical review of published reports of abnormal acritarchs from the Late Ordovician to Early Devonian, and a correlation of their occurrences with the global stable carbon isotope curve, show that high abundances of teratological forms of acritarchs are often coeval to the run-up of δC excursions. High abundances of teratological forms in modern marine protists are commonly observed in environments with a high degree of environmental stress. In the fossil record, the challenge is to attribute abnormal forms of organisms to specific environmental circumstances. Our study implies that they are somehow related to the global carbon cycle, i.e., to carbon isotopic composition of the ambient sea water, and that they share a common extrinsic cause with the contemporaneous extinction and/or turnover events in other fossil groups. © 2012 Elsevier B.
Keywords: Acritarchs; Anticosti; Gotland; Heavy metals; Ordovician; Silurian; Teratology

Systematic variations in magmatic sulphide chemistry from mid-ocean ridges, back-arc basins and island arcs - Keith, Manuel; Haase, Karsten; Klemd, Reiner; Schwarz-Schampera, Ulrich; Franke, Henrike (Chemical Geology, 2017)
Immiscible sulphide liquids preserved as magmatic sulphide globules are hosted in igneous rocks of highly variable composition formed during magmatic processes at different tectonic settings. Here we report on compositional in situ data of magmatic sulphides from mid-ocean ridge, back-arc and island arc magmatic systems. Iron-Ni-rich monosulphide solid solutions (mss) that mainly consist of pyrrhotite and pentlandite are the dominant phases in magmatic sulphide globules. In subduction-related magmas mss are most abundant in relatively evolved melts and characterised by low Ni and high Fe contents, as well as low Ni/Cu ratios (< 1). In contrast, mss from mid-ocean ridges and back-arcs without subduction input occur in mafic rocks and have high Ni/Cu ratios (> 1). Thus, mss chemistry varies systematically in lavas from the different tectonic settings in terms of their Fe-Ni distribution and Ni/Cu ratio. The observed mineralogical and chemical variations between mss from the different settings reflect early S saturation accompanied by olivine fractionation along mid-ocean ridges compared to later stage S saturation in arc systems associated with Fe-Ti oxide fractionation. These systematics are probably related to the relatively oxidised character of subduction zone magmas opposed to more reduced mid-ocean ridge melts. Large Ni/Cu variations in mss from the same locality and in individual samples suggest that S saturation is a multistage or continuous process leading to inclusions of magmatic sulphides that represent different fractionation stages in the ascending magm
Keywords: Chalcophile elements; Magmatic sulphides; Monosulphide solid solutions; Oxygen fugacity; Sulphur saturation

Systematic variations of trace element and sulfur isotope compositions in pyrite with stratigraphic depth in the Skouriotissa volcanic-hosted massive sulfide deposit, Troodos ophiolite, Cyprus - Keith, Manuel; Haase, Karsten; Klemd, Reiner; Krumm, Stefan; Strauss, Harald (Chemical Geology, 2016)

System controls of coastal and open ocean oxygen depletion - Pitcher, Grant C.; Aguirre-Velarde, Arturo; Breitburg, Denise; Cardich, Jorge; Carstensen, Jacob; Conley, Daniel J.; Dewitte, Boris; Engel, Anja; Espinoza-Morriberón, Dante; Flores, Georgina; Garçon, Véronique; Graco, Michelle; et al. (Progress in Oceanography, 2021)
The epoch of the Anthropocene, a period during which human activity has been the dominant influence on climate and the environment, has witnessed a decline in oxygen concentrations and an expansion of oxygen-depleted environments in both coastal and open ocean systems since the middle of the 20th century. This paper provides a review of system-specific drivers of low oxygen in a range of case studies representing marine systems in the open ocean, on continental shelves, in enclosed seas and in the coastal environment. Identification of similar and contrasting responses within and across system types and corresponding oxygen regimes is shown to be informative both in understanding and isolating key controlling processes and provides a sound basis for predicting change under anticipated future conditions. Case studies were selected to achieve a balance in system diversity and global coverage. Each case study describes system attributes, including the present-day oxygen environment and known trends in oxygen concentrations over time. Central to each case study is the identification of the physical and biogeochemical processes that determine oxygen concentrations through the tradeoff between ventilation and respiration. Spatial distributions of oxygen and time series of oxygen data provide the opportunity to identify trends in oxygen availability and have allowed various drivers of low oxygen to be distinguished through correlative and causative relationships. Deoxygenation results from a complex interplay of hydrographic and biogeochemical processes and the superposition of these processes, some additive and others subtractive, makes attribution to any particular driver challenging. System-specific models are therefore required to achieve a quantitative understanding of these processes and of the feedbacks between processes at varying scales.
CRIS-Team Scopus Importer:2021-09-24
Keywords: Deoxygenation; Eutrophication; Global warming; Respiration; Stratification; Ventilation

Tales from a shale - taxonomy and analysis of life habits of bivalves from the Pennsylvanian Finis Shale (Virgilian) of North Central Texas - Friedel, Julia C.; Amler, Michael R.W.; Seuß, Barbara (Kölner Forum Geol. Paläont. 23, 2019)

Taphonomic and diagenetic implications of reduction spot formation in Cretaceous red beds from the Jiaolai Basin, Eastern China - Fu, Wenzhao; Turner, Peter; Clements, Thomas; Spencer, Alan R.T.; Yu, Jifeng; Yang, Yu; Guo, Bangjie; Ning, Zhenguo; Zhuo, Xizhun; Riley, Michael S.; Hilton, Jason (Journal of Asian Earth Sciences, 2023)
Green-grey coloured reduction spots are common in continental red beds through geological history and occur in a range of different lithologies and depositional environments, but their timing and mode of formation remain controversial. We investigate the Late Cretaceous to earliest Paleogene Jiaozhou Formation using borehole data from the Jiaolai Basin in Shandong province of eastern China, and consider the distribution, morphology, and geochemistry of reduction spots in these continental red beds to evaluate how the reduction spots formed. Here, we report a novel application of three-dimensional X-ray Computed Tomography (XCT) to analyse reduction spot morphology, composition and density. Our data show that individual reduction spots are spheroidal, tubular or irregular shaped, and often contain small, grey, dark brown or black organic cores, referred to as loci. Typically, reduction spots have a similar chemical composition to the host red beds, but with elevated levels of vanadium (V), lower levels of iron (Fe), and lower density. Isolated, small refractory fossils (e.g., charcoal) in the sediment alongside reduction spots but not within them indicates that microbial decay of organic labile (reactive) tissues in early diagenesis is an important control in reduction spot formation. We propose a new taphonomic model of reduction spot formation: post burial, during the primary sedimentary cycle in the groundwater zone, vanadium is released by intrastratal oxidation of titanomagnetite. Decay of organic matter creates localised reducing conditions resulting in the reduction of Fe3+ and the eventual depletion or removal of the resulting Fe2+ (altering the colour of the reduction spot). Simultaneously, the reduction of V4+ and the consequent lowering of the concentration of V as V2+ minerals occur in the reduction spot, explaining their lower density than the host sediment.
CRIS-Team Scopus Importer:2023-01-20
Keywords: 3D X-ray Computed Tomography analysis; Continental red beds; Diagenesis; Redox; Taphonomy; Vanadium

Taphonomic bias in limestones and marls – a quantitative palaeontological approach to the genesis of limestone-marl alternations - Nohl, Theresa; Munnecke, Axel; Jarochowska, Emilia (87th Annual Conference of the Paläontologische Gesellschaft, 2016)

Taphonomic bias in limestones and marls – a quantitative palaeontological approach to the genesis of limestone-marl alternations - Nohl, Theresa; Munnecke, Axel; Jarochowska, Emilia (8th Meeting on Taphonomy and Fossilization, 2019)

Taphonomy of backshore versus deep-marine collected nautilus macromphalus conchs (New Caledonia) - Seuß, Barbara; Hembree, Daniel I.; Wisshak, Max; Mapes, Royal H.; Landman, Neil (Palaios, 2015)

Taxonomical diversity and palaeobiogeographical affinity of belemnites from the Pliensbachian–Toarcian GSSP (Lusitanian Basin, Portugal) - Costa Rita, Patrícia; Duarte, Luís V.; Weis, Robert; de Baets, Kenneth (Papers in Palaeontology, 2021)
High‐resolution analysis of the late Pliensbachian – early Toarcian belemnite assemblages from the Peniche section (Lusitanian Basin) has enabled, for the first time, recognition of eight taxa of the suborder Belemnitina, previously reported from contemporaneous north‐west Tethyan and Arctic sections. The presence of Bairstowius amaliae sp. nov. in the late Pliensbachian (emaciatum Zone) represents a novelty given that hitherto the genus Bairstowius was known only from late Sinemurian and early Pliensbachian deposits. Additionally, the replacement of Bairstowius amaliae by Catateuthis longiforma, during the latest Pliensbachian, suggests an evolutionary relationship between the two taxa. This relationship suggests a new scenario for the subsequent development of endemic Toarcian Boreal–Arctic faunas, characterized by the occurrence of Catateuthis. Comparison of the Peniche belemnite fauna with coeval faunas from the Mediterranean/Submediterranean and Euro‐Boreal domains indicates taxonomic uniformity during the late Pliensbachian and early Toarcian (emaciatum and polymorphum Zones), in the north‐west Tethys. Despite the lack of a marked taxonomic turnover, the Pliensbachian–Toarcian boundary corresponds to a slight decrease in diversity observed not only in the Lusitanian Basin but also in coeval north‐western European basins. Ordination and cluster analyses indicate that the largest changes in belemnite diversity and palaeogeographical distribution occurred rather during the Toarcian Oceanic Anoxic Event (base of the levisoni Zone). This event is marked by the extinction of taxa, affecting more severely the Mediterranean/Submediterranean domain and resulting in a more pronounced provincial differentiation among north‐western European and Arctic belemnite faunas.<br

Taxonomic and ecologic transitions in Triassic marine bivalve communities - Miao, Xue; Tong, Jinnan; Huang, Yunfei; Zhang, Shiyan; Li, Peishan; Cao, Yiran; Chu, Daoliang; Kießling, Wolfgang (PeerJ, 2025)
The Permian–Triassic mass extinction was a pivotal event in shaping marine benthic ecosystems, leading to the rise of mollusks such as bivalves and gastropods as representatives of the Modern Evolutionary Fauna. However, the detailed changes in the ecological structure of marine benthic communities throughout the Triassic remain underexplored, particularly the interrelationship between taxonomic and ecological diversities. Here, we present a study on the Triassic bivalve communities from the typical shallow marine facies in South China to document regional evolutionary patterns and explore how these patterns connect to the global trends. Broad congruence in the timing of taxonomic and ecological changes was observed through the Triassic in South China. However, both the South China materials and global data revealed a decoupling of taxonomic and ecological diversities. Substantial variability in taxonomic richness was observed alongside stable ecological diversity. Taxonomic recovery occurred early in the Early Triassic, whereas ecological diversity fully recovered only in the Middle Triassic. The Carnian stage represents a significant transition in ecosystem structure, characterized by a shift towards infaunal dominance and the expansion of habitat depth.
CRIS-Team Scopus Importer:2025-05-23
Keywords: Biotic recovery; Bivalves; South China; Taxonomic and ecological diversity; Triassic

Taxonomy and diversity of slit-band gastropods (OrderPleurotomariida) and some slit bearing Caenogastropodafrom the Pennsylvanian of the USA - Karapunar, Baran; Nützel, Alexander; Seuß, Barbara; Mapes, Royal H. (Papers in Palaeontology, 2022)

Taxonomy, palaeoecology and palaeobiogeography of upper Cenomanian (Upper Cretaceous) oysters and plicatulids from southern Algeria - Benyoucef, Madani; Ghenim, Asma-Fethia; Ferre, Bruno; Ayoub-Hannaa, Wagih; Koci, Tomas; Adaci, Mohammed; Guendouz, Mohamed-Lassad; Zaoui, Djamila; Bendella, Mohamed; Bensalah, Mustapha (Historical Biology, 2021)
Palaeontological investigation of four lithostratigraphic sections documenting the upper Cenomanian shallow marine carbonates of three palaeogeographic domains of southern Algeria (western Saharan Atlas, Guir Basin and Tinrhert Hamada) has produced a comprehensive collection of large bivalve assemblages for taxonomic purposes. A first inventory list of late Cenomanian oysters and plicatulids from southern Algeria is now available and consists of 15 taxa as follows: Lopha syphax, Ostreidae gen. et sp. indet., Curvostrea rouvillei, Flemingostreidae gen. et sp. indet., Costagyra olisiponensis, Amphidonta obliquata, Ceratostreon flabellatum, Ilymatogyra africana, Rhynchostreon suborbiculatum, Gyrostrea delettrei, Gyrostrea sp. indet., Pycnodonte (Phygraea) vesicularis vesiculosa, Plicatula (Plicatula.) auressensis, Plicatula (Plicatula) batnensis, and Chondrodonta? sp. indet. These taxa build five distinctive oyster-facies patterns, all purportedly recognisable in the field for stratigraphic assignment and regional correlation. Scarce sclerobiontic assemblage (borings: Entobia, Gastrochaenolites and Oichnus; and epibionts: juvenile oysters, serpulid tubes and Berenicean-type bryozoa) observed within these oyster shell assemblages is also identified, briefly described and adressed. This first taxonomic analysis highlights three main palaeogeographic components within these oyster- and plicatuloid-assemblages: endemic Mediterranean, Tethyan-Atlantic and cosmopolitan taxa. Moreover, the present study on these late Cenomanian oyster assemblages provides a first inventory list and stratigraphical baseline data towards further datation and correlation at the regional scale.
CRIS-Team Scopus Importer:2021-11-05
Keywords: ichnology; Ostreoidea; Plicatuloidea; systematics; taphonomy

Technological and functional analysis of Upper Palaeolithic backed micro-blades from southern Oman Technologische und funktionale Analyse jungpaläolithischer Mikroklingen aus dem südlichen Oman - Hilbert, Yamandú; Clemente-Conte, Ignacio; López Correa, Matthias; al-Fudhaili, Najat; Mazzoli, Claudio (Hugo Obermaier-Society for Quaternary Research and Archaeology of the Stone Age, 2022)
While a considerable amount of information on the Pleistocene human occupation of South Arabia has been gathered by archaeologists over the course of the last decades, little is known about the Upper Palaeolithic period and its local specificities. This is evidently a function of the still poor archaeological record for this period and the difficulties in finding stratified and therefore datable occurrences in general. Here, we present the traceological and technological analysis of the stone tools from one of the few archaeological sites in Oman dating between 33,000 to 30,000 years ago, which has yielded a small but important assemblage of backed tools initially suggested to be projectiles. The bi-pointed backed micro-blades from Mutafah 1 share specific technological and morphological features making it germane to suggest comparable operational sequences for the manufacture of these pieces. Our analysis, which identified specific traces of use related to both hunting and domestic activities, as well as microscopic residues on the backed micro-blades, indicates that the Mutafah 1 tools were part of a toolkit with wide applications reflecting the highly opportunistic nature of the Upper Palaeolithic human occupation of South Arabia.
CRIS-Team Scopus Importer:2024-12-16
Keywords: hunting; South Arabia; Stone tools; technology; traceology

Tectonic and crustal evolution of the Shackleton Range, East Antarctica: Geochemical and isotope contraints - Will, T. M.; Frimmel, H. E.; Zeh, A.; Le Roux, Petrus; Schmädicke, Esther (Precambrian Research, 2010)
UnivIS-Import:2017-03-24:Pub.2010.nat.dgeo.IGM.profes_1.texton

Tectonic and volcanic controls on Early Jurassic rift-valley lake deposits interleaved with Karoo flood basalts, Southern Namibia. - Stollhofen, Harald; Gerschütz, Stephan; Stanistreet, Ian G.; Lorenz, Volker (Palaeogeography, Palaeoclimatology, Palaeoecology, 1998)
The Karoo Igneous Province of southern Africa is one of the classic Mesozoic flood basalt provinces of the world. In the case of the early Jurassic Kalkrand Formation of Namibia the succession comprises three major flood basalt units that are separated by two stratigraphically important fluvio-lacustrine interlayers. These horizons preserve a record of the complex interplay between sedimentation, effusion of Karoo flood basalts and extensional tectonics that predated and accompanied the break-up of Gondwanaland. Both sediment layers start with the dominantly local derivation of weathered and eroded lava debris, followed by the emplacement of subaqueous mass flows and subsequent deposition of chemical sediments. The latter are characterised by interbedded stromatolitic carbonates, grass-like structured gypsum, and plane-bedded sandstones and mudstones containing euhedral displacive gypsum crystals that grew in the subsurface as well as rosettes which nucleated on the sediment surface. The central parts of the lacustrine units are overlain by thin deltaic sandstones showing bottomset, foreset, and topset layering and, finally, braided fluvial, trough cross-bedded sandstones. Evidence of subsidence synchronous with the formation of lake bodies can be explained by two principal mechanisms. The first acted in localised areas only and is reflected by the development of small, centrally subsiding basins. From the repeated occurrence of onlapping geometries within such a pool, a multiphase history of sagging is deduced, being most likely related to periodic magma withdrawal and reduction in magmatic pressures in subsurface lava feeders beneath the basin floor. Abundant syn-subsident fracture features at lava–sediment contacts, such as sediment-, hydrothermal calcite-, and sometimes basic lava-filled fissure systems indicate the pronounced interaction between the underlying volcanics and these small areas of pronounced subsidence. Fluids passing through the volcanic pile exhaled into the lake, giving it the characteristics of alkaline lake systems described from more recent flood basalt areas associated with the modern African Rift System. On the regional scale, however, northerly trending extensional fault systems controlled half-graben basin geometries and both facies and thickness variations across faults indicate that tectonism operated contemporaneously with volcanism and lacustrine sedimentation. The analysis of faults and associated structures, such as regularly aligned sediment-filled fissures, sets of micro-faults, folds and basaltic dykes constrains the extensional opening direction for the Karoo graben structures in this area that heralded the opening of the South Atlantic and thus provides a basis to discuss the extensional history of the Namibian coastal margin within the regional tectonic framework.
UnivIS-Import:2015-03-05:Pub.1998.nat.dgeo.IGM.LG.tecton
Keywords: Gondwana; Namibia; Karoo; Drakensberg Group; flood basalts; lakes; palaeolimnology

Tectonic blocks and molecular clocks - de Baets, Kenneth; Antonelli, Alexandre; Donoghue, Philip C. J. (Philosophical Transactions of the Royal Society B-Biological Sciences, 2016)
This article is part of the themed issue 'Dating species divergences using rocks and clocks'.
Keywords: molecular clock; calibration; fossil record; biogeography; tectonics

Tectonic control of ocean island basalt sources on São Miguel island, Azores? - Haase, Karsten; Beier, Christoph (Geophysical Research Letters, 2003)
The calderas of the two isotopically distinct volcanoes Sete Cidades and Agua de Pau on São Miguel are only 30 km apart. Sete Cidades lavas generally have 87Sr/86Sr < 0.7038 while Agua de Pau lavas have 87Sr/86Sr > 0.7040. Two overlapping rift zones exist between the two volcanoes and the lava compositions show that each rift zone is connected to the neighbouring volcano. Limited mixing between the volcanic systems implies separate ascent paths and magma sources with diameters of ∼20 km. The two volcanic systems follow contrasting directions; the Sete Cidades volcanic rift strikes NW parallel to the extensional Terceira Rift, while the Agua de Pau volcanic rift zone strikes E-W. The covariation of magma sources and lithospheric tectonics may suggest that the tectonic structure of the lithosphere controls the mantle upwelling beneath São Miguel.
UnivIS-Import:2015-03-09:Pub.2003.nat.dgeo.IGM.legeo.tecton
Keywords: Basalt; Geochemistry; Isotopes; Magma reservoir; Rift zones

Tectonic control on the genesis of magmas in the New Hebrides arc (Vanuatu) - Beier, Christoph; Brandl, Philipp; Martins Lima, Selma Sofia; Haase, Karsten (Lithos, 2018)
Keywords: Vanuatu; Silicic melt; Structural control; Island arc; Geodynamics; New Hebrides; Magma evolution

Tectonic events, continental intraplate volcanism and mantle plume activity in northern Arabia: constraints from geochemistry and Ar-Ar dating of Syrian lavas. - Krienitz, Marc-Sebastian; Haase, Karsten; Mezger, Klaus; van den Bogaard, Paul; Thiemann, Viola; Shaikh-Mashail, M.A. (Geochemistry Geophysics Geosystems, 2009)
[1] New 40Ar/39Ar ages combined with chemical and Sr, Nd, and Pb isotope data for volcanic rocks from Syria along with published data of Syrian and Arabian lavas constrain the spatiotemporal evolution of volcanism, melting regime, and magmatic sources contributing to the volcanic activity in northern Arabia. Several volcanic phases occurred in different parts of Syria in the last 20 Ma that partly correlate with different tectonic events like displacements along the Dead Sea Fault system or slab break-off beneath the Bitlis suture zone, although the large volume of magmas and their composition suggest that hot mantle material caused volcanism. Low Ce/Pb (<20), Nb/Th (<10), and Sr, Nd, and Pb isotope variations of Syrian lavas indicate the role of crustal contamination in magma genesis, and contamination of magmas with up to 30% of continental crustal material can explain their 87Sr/86Sr. Fractionation-corrected major element compositions and REE ratios of uncontaminated lavas suggest a pressure-controlled melting regime in western Arabia that varies from shallow and high-degree melt formation in the south to increasingly deeper regions and lower extents of the beginning melting process northward. Temperature estimates of calculated primary, crustally uncontaminated Arabian lavas indicate their formation at elevated mantle temperatures (Texcess ̃ 100-200°C) being characteristic for their generation in a plume mantle region. The Sr, Nd, and Pb isotope systematic of crustally uncontaminated Syrian lavas reveal a sublithospheric and a mantle plume source involvement in their formation, whereas a (hydrous) lithospheric origin of lavas can be excluded on the basis of negative correlations between Ba/La and K/La. The characteristically high 206Pb/204Pb (̃19.5) of the mantle plume source can be explained by material entrainment associated with the Afar mantle plume. The Syrian volcanic rocks are generally younger than lavas from the southern Afro-Arabian region, indicating a northward progression of the commencing volcanism since the arrival of the Afar mantle plume beneath Ethiopia/Djibouti some 30 Ma ago. The distribution of crustally uncontaminated high 206Pb/204Pb lavas in Arabia indicates a spatial influence of the Afar plume of ̃2600 km in northward direction with an estimated flow velocity of plume material on the order of 22 cm/a. © 2009 by the American Geophysical Union.
UnivIS-Import:2015-03-09:Pub.2009.nat.dgeo.IGM.legeo.tecton
Keywords: Afar; Intraplate volcanism; Mantle plume; Syria

Tectonic evolution of the central steep zone, axum area, Northern Ethiopia: Inferences from magnetic and geochemical data - de Wall, Helga; et al. (2011)

Tectonic focusing of voluminous basaltic eruptions in magma-deficient backarc rifts - Anderson, Melissa; Hannington, Mark; Haase, Karsten; Schwarz-Schampera, Ulrich; Augustin, Nico; McConachy, Tim; Allen, Katie (Earth and Planetary Science Letters, 2016)
The Coriolis Troughs of the New Hebrides subduction zone are among the youngest backarc rifts in the world. They reach depths of >3 km, despite their small size (<100 km in length and only 25-45 km wide) and their proximity to the arc front ( 50 km). The narrow, deep graben morphology is characteristic of magma-deficient arc rifts in the early stages of backarc extension, where the rate of extension and subsidence exceeds the magmatic input. Unexpectedly, the youngest graben, the Vate Trough, contains a centrally-located 1000-tall and 14-km wide shield volcano with a large, 5×8 km breached summit caldera. The Nifonea axial volcano has a volume of 126 km, reflecting unusually high extrusion rates, given its young age (<3 Ma), and the summit caldera hosts the remnants of a large lava lake, the first described from a submarine backarc setting. Extensive diffuse hydrothermal venting and several clusters of black smoker chimneys, with the highest recorded fluid temperatures (368C) in the SW Pacific, occur on the youngest lava flows. Comparison with similar axial volcanoes on the mid-ocean ridges suggests that the 46×10 m of sheet flows in the caldera could have been erupted in <30 hours. The focusing of voluminous basaltic eruptions into an otherwise magma-deficient backarc has been linked to strong left-lateral transtension caused by clockwise rotation and segmentation of the southern portion of the arc after collision with d'Entrecasteaux ridge. This study shows that the upper plate stresses can result in dramatic variability in magma supply and hydrothermal activity at the earliest stages of arc rifting and could explain the wide range of melt compositions, volcanic styles and mineral deposit types found in nascent backarc rifts.
Keywords: Backarc magmatism; Lava lake; Nifonea; Ridge collision; Seafloor sulfides; Vate Trough

Tectonic impact on sediment routing systems of evolving rift basins: A case study from the Cenozoic Kerimbas Graben, offshore northern Mozambique - Eberts, Andreas; Kaufmann, Dirk; Stollhofen, Harald; Franke, Dieter (17th Symposium of Tectonics, Structural Geology and Crystalline Geology (TSK), 2018)
Knowledge of the submarine channel architecture and of related tectonosedimentary processes is crucial to assess sediment influx and to locate potential hydrocarbon reservoirs. Such systems are highly sensitive to changes of seabed topography, often strongly linked to tectonic uplift, faulting and seismicity. To reveal the impact of tectonic activity on channel pathways, we carried out a morphotectonic analysis of the Kerimbas Graben, an active rift basin situated in the Mozambique Channel. This area is highly influenced by the Cenozoic to recent tectonic evolution of the East African Rift System. Three high-quality geophysical datasets including high-resolution bathymetric, multichannel reflection seismic and Parasound data were acquired during two cruises of the research vessel SONNE in early 2014. By combining these datasets, we were able to map the lateral and vertical extent of topographic features such as fault scarps and channel incisions, and to interpret them in terms of their relation to tectonic activity. Our results show that the study area is divided into two distinct parts, comprising differences in both morphotectonic characteristics and in the evolution of channel pathways. The northern part, occupied by the Kerimbas Graben, shows N-S trending fault scarps the most pronounced of which are associated with the eastern and western border faults of the rift basin. Farther south, an area of “diffuse extension” is accompanied by horst-and-graben structures, acting as right-stepping transfer zones for the southward impinging eastern border fault. The observed spatial variations are also represented by differences in fault throw, revealing that fault scarps in the southern part of the study area show significantly lower vertical offsets. By assuming a roughly coherent age of the corresponding faults this suggests higher uplift rates in the Kerimbas Graben area, which in turn would imply differences in the impact of tectonics on sediment routing systems along strike of the rift. Concerning this, two basic types of interactions in the downstream parts of submarine channel systems can be inferred: (1) a complete blocking of the channel pathway occurred in areas where the rate of rift shoulder uplift exceeded the rate of channel incision. Uplifted channel remnants on the eastern rift flank of the Kerimbas Graben are indicative for this process. Since they were formed at least during the Late Miocene, they confirm Cenozoic tectonics to be responsible for the formation of the rift basin; (2) In contrast, active incision into the rift shoulder occurred in areas where the uplift rate of the shoulder is substantially lower than the downward erosion of the channel system. This is most likely the case for the southern part of the study area where a channel has incised deeply into the eastern rift shoulder. Based on these results, we established an evolutionary model for the interaction of tectonic activity and sediment routing systems of the Kerimbas Graben and adjacent southern areas, ranging from the Late Miocene to recent time

Tectonic implications for the German Continental Deep Drilling Program (KTB) derived from paleomagnetic studies on lamprophyres - de Wall, Helga; et al. (Zentralblatt für Geologie und Paläontologie, Teil I, Geologie, 1995)
UnivIS-Import:2015-03-05:Pub.1995.nat.dgeo.IGM.c3tekt.tecton

Tectonics and kinematics of an Alpine shear zone near As Sifah (NE Oman) - Al Harthy, Salima; Bauer, Wilfried; Handoniaina, Jean Aline Nadia; Al Maawali, Hanan; Wischer, Joschka; Tamas, Dan M. (Arabian Journal of Geosciences, 2022)
The Saih Hatat Dome forms a tectonic window under the overlying allochthonous Samail ophiolite and nappes composed of sediments from the Neotethyan Hawasina Basin. In this window, high- to ultra-high pressure/low-temperature eclogites and blueschists of the so-called lower plate are tectonically overlain by metamorphic rocks, forming the so-called upper plate. In 2018, the footwall of the discontinuity became exposed in a 650-m-long and up to 37-m-deep road cut which gave an insight to structural elements in these highly sheared blueschists. Kinematic indicators point to a top-to-north simple shear movement along low-angle discrete shear zones of decimeter to meter thickness, alternating with low-strain zones that are occupied by folded competent rocks. Fold axes are aligned parallel to the mineral stretching lineations and were formed by simple shear-related shortening of a steep limb of a pre-existing N-S oriented syncline. The structural inventory of the outcrop can be interpreted as the result of the Late Cretaceous exhumation of the NE corner of the Arabian Plate.
CRIS-Team WoS Importer:2022-04-08

Tectonic structures in the Stumsnäs 1 core from the southern Siljan Ring, central Sweden: Ordovician sediments sandwiched between Proterozoic basement slivers. - Arslan, Arzu; Meinhold, Guido; Lehnert, Oliver (Gff, 2013)
UnivIS-Import:2015-03-09:Pub.2013.nat.dgeo.IGM.LG.tecton

Tellurium and selenium systematics in mafic VMS from Cyprus: mineral, mound and regional scale controls - Martin, Andrew J.; Mcdonald, Lain; Mcfall, Katie A.; Macleod, Christopher J.; Keith, Manuel; Jenkin, Gawen R. T.; Boyce, Adrian J. (LIFE WITH ORE DEPOSITS ON EARTH, PROCEEDINGS OF THE 15TH SGA BIENNIAL MEETING, 2019, VOLS 1-4, 2019)
CRIS-Team WoS Importer:2020-01-10

Tellurium in Late Permian-Early Triassic Sediments as a Proxy for Siberian Flood Basalt Volcanism - Regelous, Marcel; Regelous, Anette; Grasby, Stephen E.; Bond, David P.G.; Haase, Karsten; Gleißner, Stefan; Wignall, Paul B. (Geochemistry Geophysics Geosystems, 2020)
We measured the concentrations of trace elements in Late Permian to Early Triassic sediments from Spitsbergen. High mercury concentrations in sediments from the level of the Permo-Triassic Mass Extinction (PTME) at this location were previously attributed to the emplacement of the Siberian Traps Large Igneous Province and used to link the timing of volcanism with the record of environmental change and extinction in these sediments. We investigated the use of the moderately to highly volatile, siderophile elements Ni, Zn, Cd, Sb, Te, Re, and Tl as proxies for the intensity of Siberian volcanism. These trace elements, like Hg, have high concentrations in volcanic gas compared to crustal rocks. Tellurium is highly enriched at the PTME, and Te/Th ratios increase by a factor of ∼20 across the PTME, similar to the variation in Hg/total organic carbon (TOC) in the same samples. Te/Th and Hg/TOC values imply that Siberian volcanism initiated at the onset of the PTME, coincident with the start of the δ13Corganic excursion and abrupt warming. Based on Te and Hg, most Siberian volcanism occurred between the two phases of the PTME boundary (a period of less than 100 ky), but also continued into the Early Triassic. The duration of Siberian volcanism inferred from Te/Th and Hg/TOC is shorter than that indicated by recent high-precision U-Pb ages of Siberian intrusive and extrusive rocks. Te concentrations and Te/Th ratios in sediments represent a useful new proxy for volcanism, which can be used to link the marine sedimentary record with large volcanic events on land.
CRIS-Team Scopus Importer:2020-11-27

Temperature-controlled Se-S isotope fractionation during seawater mixing and sulfide precipitation in black smoker chimneys - Grosche, Anna; Keith, Manuel; Klemd, Reiner; Strauss, Harald; Rosca, Carolina; König, Stephan (Geochimica Et Cosmochimica Acta, 2024)
Submarine hydrothermal venting leads to the formation of black smoker chimneys with complex internal zoning. These emerge through mineral precipitation under changing fluid conditions caused by variable degrees of fluid-seawater mixing. This study explores the potential of selenium (Se) isotopes as a novel tool to understand the enrichment processes and identify the sources of chalcophile elements in seafloor hydrothermal systems. In-situ trace element analysis of hydrothermal sulfides combined with high-precision Se and S isotope analysis of micro-domains through the wall of black smoker chimneys from the Nifonea vent field (New Hebrides back-arc, SW Pacific) revealed variations in sulfide chemistry at small spatial resolution. The δ82/76Se values (deviation of 82Se/76Se relative to NIST SRM 3149) of the sulfide micro-domains range from +0.6 to −3.7 ‰ ± 0.2 ‰ (2 s.d.) with a general decrease from the inner chalcopyrite lining towards the outer chimney wall. The highest δ82/76Se values overlap with the mean value of fresh basaltic glass from Nifonea caldera (+0.6 ± 0.4 ‰, n = 4), indicating that Se is primarily leached from the surrounding back-arc basalts. The trace element contents of sulfides revealed systematic variations between vent sites, linked to differences in fluid vapor content induced by sub-seafloor boiling, which did not cause any Se isotope fractionation. Instead, decreasing Se/Tl ratios of pyrite together with decreasing δ82/76Se values of sulfide micro-domains and calculated δ34SH2S fluid values towards the outer chimney wall are indicative of temperature-dependent Se and S isotope fractionation at 370 to <200 °C during fluid-seawater mixing within the chimney wall. This study presents Se isotopes as a new robust instrument to unravel the sources of chalcophile elements and related fluid processes in seawater-diluted hydrothermal systems, enhancing our understanding of their geochemical complexities.
CRIS-Team Scopus Importer:2024-04-05
Keywords: Black smoker; Hydrothermal vent; Metal sources; Selenium; Stable isotopes

Temperature dependent grain boundary migration in deformed-then-annealed material: Observations from experimentally deformed synthetic rocksalt - Bestmann, Michel; et al. (Tectonophysics, 2006)
Keywords: Annealing; Grain boundary migration; Heating experiments; Post-deformational annealing; Rocksalt

Temperature-dependent late hydration of calcium aluminate cement in a mix with calcite – Potential of G-factor quantification combined with GEMS-predicted phase content - Goergens, Julian; Götz-Neunhoeffer, Friedlinde (Cement, 2021)
In continuation of earlier work on early hydration, this study evaluates the late hydration of CAC and CaCO3 using QXRD and thermodynamic modelling at different temperatures. Experiments were performed at 5, 23, 40 and 60 °C for up to one year. As stated in the preceding study, C2AHX might act as a precursor for monocarbonate in early hydration, and thus no or only little monocarbonate should form at temperatures below 20 °C. At 5 °C, monocarbonate starts precipitating after 7 d and remains alongside CAH10. At all other investigated temperatures, monocarbonate is the dominant hydrate phase. Primarily formed CAH10 at 23 °C is visible up to 14 d but then becomes unstable with respect to monocarbonate. At 23 °C and 40 °C the thermodynamically stable phase assemblage is reached within one year. However, the precipitation of C3AH6 is detected in all samples at 60 °C, which results from an insufficient w/CAC ratio for carbonate-AFm in the paste due to the inevitable evaporation of mixing water for this condition. However, C3AH6 can partly be “re-converted” at 60 °C when the sample is subsequently stored under water and monocarbonate is stable again.
Keywords: Hydration (A); Temperature (A); Thermodynamic calculations (B); X-ray diffraction (B); Calcite (D); Calcium aluminate cement (D)

Temperature Effects on the Distribution of Aragonitic and Calcite-Secreting Epifaunal Bivalves - Eichenseer, Kilian; Balthasar, Uwe; Smart, Christopher W; Kießling, Wolfgang (Journal of Biogeography, 2024)
Aim: To test if temperature significantly influences the global biogeographic distribution of marine epifaunal bivalves via their skeletal mineralogy. Location: Global. Taxa: Marine, epifaunal bivalves. Methods: The skeletal mineralogy of 45,789 epifaunal bivalve occurrences from 669 species from the Ocean Biodiversity Information System (OBIS) was related to sea surface temperatures from Bio-ORACLE. Binomial regression was used to assess the influence of temperature and seasonality on the distribution of aragonitic and calcite-secreting bivalve occurrences, aggregated in equal-area grid cells. Results: The proportion of aragonitic bivalve occurrences significantly increases with mean annual temperature in our global analysis and most marine biogeographic realms. A greater prevalence of calcite-secreting bivalves in seasonal climates could be shown at low mean annual temperatures at the global scale but not within biogeographic realms. Main Conclusions: The global biogeographic distribution of epifaunal bivalves is significantly influenced by water temperature via their skeletal mineralogy. The mechanism driving this pattern is best explained by the temperature modulation of the effect of Mg2+ on calcite growth. Although this Mg2+ effect predicts an advantage for aragonite secretion at higher temperatures, poleward migration in response to higher temperature extremes will expose tropical taxa to cooler temperatures in the cold season, which may impede aragonite secretion in taxa not adapted to these climates. Significance: Our results suggest that skeletal mineralogy is likely to influence ocean warming-induced migration patterns.
CRIS-Team Scopus Importer:2024-11-15
Keywords: aragonite; bivalves; calcite; climate change; macroecology; shell mineralogy

Temporal offset between precipitation and water uptake of Mediterranean pine trees varies with elevation and season - Juhlke, Tobias; van Geldern, Robert; Barth, Johannes; Bendix, J.; Bräuning, Achim; Garel, E.; Häusser, Martin; Huneau, F.; Knerr, I.; Santoni, S.; Szymczak, Sonja; Trachte, K. (Science of the Total Environment, 2021)
For climate models that use paleo-environment data to predict future climate change, tree-ring isotope variations are one important archive for the reconstruction of paleo-hydrological conditions. Due to the rather complicated pathway of water, starting from precipitation until its uptake by trees and the final incorporation of its components into tree-ring cellulose, a closer inspection of seasonal variations of tree water uptake is important. In this study, branch and needle samples of two pine species (Pinus pinaster and Pinus nigra subsp. laricio) and several water compartments (precipitation, creek, soil) were sampled over a two-year period and analyzed for the temporal variations of their oxygen and hydrogen stable isotope ratios (δ18O and δ2H) at five sites over an elevation gradient from sea level to around 1600 m a.s.l. on the Mediterranean island of Corsica (France). A new model was established to disentangle temporal relationships of source water uptake of trees. It uses a calculation method that incorporates the two processes mostly expected to affect source water composition: mixing of waters and evaporation. The model results showed that the temporal offset from precipitation to water uptake is not constant and varies with elevation and season. Overall, seasonal source water origin was shown to be dominated by precipitation from autumn and spring. While autumn precipitation was a more important water source for trees growing at mid- ( 800–1000 m a.s.l) and high-elevation ( 1600 m a.s.l.) sites, trees at coastal sites mostly took up water from late winter and spring. These findings show that predicted decreases in precipitation amounts during the wet season in the Mediterranean can have strong impacts on water availability for pine trees, especially at higher elevations.
CRIS-Team Scopus Importer:2020-10-16
Keywords: Hydrogen isotopes; Mediterranean; Oxygen isotopes; Pine trees; Soil water; Water uptake

Temporal variations in the incompatible trace element systematics of Archean TTGs: Implications for crustal growth and tectonic processes in the early Earth - Sotiriou, Paul; Polat, Ali; Windley, Brian; Kusky, Timothy (Earth-Science Reviews, 2023)
In this study, we applied classification and tectonic setting diagrams, N-MORB-normalised trace element and incompatible element temporal variation diagrams, Nb/Nb*, Pb/Pb*, La/Smn, La/Nbn, Th/Nbn and Pb/Cen ratios and field-structural relationships to Archean tonalites, trondhjemites and granodiorites (TTGs) and Phanerozoic arc-generated TTGs. Geochemical analyses were compiled from the literature to elucidate how Archean continental crust formed, whether plate tectonics operated in the Archean, if this Archean form of plate tectonics resembled modern-style plate tectonics, and when plate tectonics commenced in the early Earth. The Archean TTGs used for this study were not noticeably influenced by alteration or crustal contamination; therefore, their geochemistry is indicative of their original juvenile sources and the tectonic environments in which they were generated. These rocks are predominantly calcic to calc-alkalic and magnesian granitoids derived from low-K mafic/tholeiitic sources. Most Archean TTGs have high La/Ybcn and Sr/Y ratios and low Ybcn values and Y contents characteristic of adakites and formed by partial melting of subducting oceanic crust or the lower arc crust. However, some Archean TTGs resemble modern arc andesites, dacites and rhyolites that have low La/Ybcn and Sr/Y ratios and high Ybcn values and Y contents and formed by fractional crystallisation of basaltic magmas derived from partial melting of the sub-arc mantle wedge. Archean TTGs overlap with their Phanerozoic counterparts and mainly plot in the arc fields of tectonic setting discrimination diagrams. The N-MORB-normalised trace element patterns of Archean TTGs from well-studied cratons bear a striking resemblance to those of TTGs from modern active arcs (e.g., Izu-Bonin-Mariana, Andean) and from older Phanerozoic arcs (e.g., Sierra Nevada, Gangdese), consistent with their formation in arcs. The temporal variations in the trace element geochemistry of Archean TTGs underwent a noticeable change on a global scale at ca. 3500–3200 Ma. The vast majority (99%) of Archean TTGs have Nb/Nb* and Pb/Pb* anomaly ratios of <1 and >1, respectively, and are interpreted to have formed in arc settings; the remainder had non-arc origins. The La/Smn, La/Nbn, Th/Nbn and Pb/Cen ratios of these TTGs suggest that 99% of these rocks formed in supra-subduction zone settings, namely arcs, forearcs and back-arcs, the remainder being derived from mantle plumes and mid-ocean ridges. This study suggests that throughout the Archean TTGs were generated in subduction zones by modern-style plate tectonic processes, beginning in the Hadean (>4000 Ma). TTGs began to form in intra-oceanic arcs at ca. 4020 Ma prior to a global-scale switch to Andean-style continental arc magmatism at ca. 3500–3200 Ma, which led to the genesis of TTGs in continental arcs worldwide in the Paleoarchean. Modern-style plate tectonic processes predominantly contributed to the formation of Archean continental crust. As such, global-scale vertical tectonic processes did not play a significant role in the formation of Archean continental crust. Most plutons are emplaced vertically into the crust, as exemplified by modern arcs. Vertical tectonic processes are locally observed in Archean cratons, leading many researchers to erroneously conclude that vertical tectonic processes were predominant in the early Earth.
CRIS-Team Scopus Importer:2023-01-06
Keywords: Archean tectonics; Early Earth processes; Incompatible trace element systematics; TTG petrogenesis; TTGs

Temporal variations in the incompatible trace element systematics of Archean volcanic rocks: Implications for tectonic processes in the early Earth - Sotiriou, Paul; Polat, Ali; Windley, Brian F.; Kusky, Timothy (Precambrian Research, 2022)
Temporal variations in the incompatible trace element geochemistry of volcanic rocks in Archean greenstone belts have major implications for the style of tectonics that operated in the early Earth, and if and when plate tectonic processes occurred in the Archean, which are still subjects of substantial debate. Comparing the geochemistry of Archean volcanic rocks with that of Phanerozoic arc volcanic rocks has the potential to shed light on these questions. Geochemical data from 8,249 Eoarchean to Neoarchean volcanic rocks and 20,099 Phanerozoic arc volcanic rocks were compiled from the literature to address the above questions through the application of temporal incompatible trace element ratio variations, N-MORB-normalised trace element diagrams, and tectonic setting discrimination diagrams. The sampled rocks range in composition from ultramafic through basaltic and andesitic to dacitic/rhyolitic. Most of the incorporated Archean volcanic rocks were deemed to have been unaffected by significant alteration or crustal contamination in the literature and, therefore, to reflect their provenance, a feature that was corroborated by this study. Most of these Archean volcanic rocks plot in the plate margin, oceanic arc and continental arc fields in classification and tectonic setting discrimination diagrams, with the remainder plotting in the alkaline arc, mid-ocean ridge and oceanic island fields. Comparison between N-MORB-normalised trace element diagrams of volcanic rocks from well-studied Archean greenstone belts in Greenland, Canada, South Africa, China, Australia, India, Brazil and Finland and volcanic rocks from well-studied modern arcs demonstrates that their trace element patterns are remarkably similar. This indicates that the former formed in arc-related settings by modern-style plate tectonic processes that operated throughout the Archean. The Pb and Nb anomalies of most Archean volcanic rocks are fully consistent with an arc-related setting. The temporal variations in the incompatible trace element ratios of Archean volcanic rocks, coupled with their lithological associations, demonstrate that intra-oceanic arc magmatism was prominent in the Eoarchean before a shift in these ratios in the Paleoarchean signified the beginning of Andean-style continental arc magmatism between 3500 and 3200 Ma. Modern-style plate tectonic processes were a far more important contributor to Archean crustal growth and evolution than sagduction-driven vertical tectonic processes.
CRIS-Team Scopus Importer:2021-12-17
Keywords: Archean tectonics; Archean volcanic rocks; Modern arc volcanic rocks; Temporal variation; Trace element systematics

Testing for the effects of depositional rates in multiproxy models of environmental and faunal change: the Silurian Lau δ13C excursion - Grohganz, Madleen; Jarochowska, Emilia; Hohmann, Niklas; Munnecke, Axel (11th North American Paleontological Convention, 2019)

Testing the limits of Paleozoic chronostratigraphic correlation via high-resolution (<500 kyr) integrated conodont, graptolite, and carbon isotope (d13C-carb) biochemostratigraphy across the Llandovery-Wenlock (Silurian) boundary: Is a unified Phanerozoic timescale achievable? - Cramer, Bradley D.; Loydell, David K.; Samtleben, Christian; Munnecke, Axel; Kaljo, Dimitri; Maennik, Peep; Martma, Tonu; Jeppsson, Lennart; Kleffner, Mark A.; Barrick, James E.; Johnson, Craig A.; Emsbo, Poul; et al. (Geological Society of America Bulletin, 2010)
<p style="box-sizing: border-box; margin: 0px 0px 1rem; padding: 0px; border: 0px; font-variant-numeric: inherit; font-stretch: inherit; font-size: medium; line-height: 1.7em; font-family: Lato, sans-serif; vertical-align: baseline; color: rgb(51, 51, 51);"> The resolution and fidelity of global chronostratigraphic correlation are direct functions of the time period under consideration. By virtue of deep-ocean cores and astrochronology, the Cenozoic and Mesozoic time scales carry error bars of a few thousand years (k.y.) to a few hundred k.y. In contrast, most of the Paleozoic time scale carries error bars of plus or minus a few million years (m.y.), and chronostratigraphic control better than ±1 m.y. is considered “high resolution.” The general lack of Paleozoic abyssal sediments and paucity of orbitally tuned Paleozoic data series combined with the relative incompleteness of the Paleozoic stratigraphic record have proven historically to be such an obstacle to intercontinental chronostratigraphic correlation that resolving the Paleozoic time scale to the level achieved during the Mesozoic and Cenozoic was viewed as impractical, impossible, or both. <p style="box-sizing: border-box; margin: 0px 0px 1rem; padding: 0px; border: 0px; font-variant-numeric: inherit; font-stretch: inherit; font-size: medium; line-height: 1.7em; font-family: Lato, sans-serif; vertical-align: baseline; color: rgb(51, 51, 51);"> Here, we utilize integrated graptolite, conodont, and carbonate carbon isotope (δ<span style="box-sizing: border-box; margin: 0px 0.2em; padding: 0px; border: 0px; font-style: inherit; font-variant: inherit; font-weight: bold; font-stretch: inherit; font-size: 13px; line-height: inherit; font-family: "Source Sans Pro", sans-serif; vertical-align: baseline; position: relative; top: -0.75em;">13C<sub style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit;">carb) data from three paleocontinents (Baltica, Avalonia, and Laurentia) to demonstrate chronostratigraphic control for upper Llandovery through middle Wenlock (Telychian–Sheinwoodian, ∼436–426 Ma) strata with a resolution of a few hundred k.y. The interval surrounding the base of the Wenlock Series can now be correlated globally with precision approaching 100 k.y., but some intervals (e.g., uppermost Telychian and upper Sheinwoodian) are either yet to be studied in sufficient detail or do not show sufficient biologic speciation and/or extinction or carbon isotopic features to delineate such small time slices. Although producing such resolution during the Paleozoic presents an array of challenges unique to the era, we have begun to demonstrate that erecting a Paleozoic time scale comparable to that of younger eras is achievable.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LG.testin
Keywords: chronostratigraphy; Paleozoic; chronostratigraphic correlation; conodont; graptolite; carbon isotope; dC13; stratigraphy; chemostratigraphy; Llandovery; Wenlock; boundary; time scale

Testing the role of biological interactions for the evolution of mid-Mesozoic marine benthic ecosystems - Aberhan, Martin; Kießling, Wolfgang; Fürsich, Franz (Paleobiology, 2006)
Evaluating the relative importance of biotic versus abiotic factors in governing macro-evolutionary patterns is a central question of paleobiology. Here, we analyzed patterns of changes in global relative abundances and diversity of ecological groups to infer the role of biological interactions as driving evolutionary forces in mid-Mesozoic macrobenthic marine ecosystems. Specifically, we tested the hypothesis of escalation, which states that macroevolutionary patterns were controlled by an increasing pressure exerted by enemies on their victims. Associated with evidence of increasing levels of predation and biogenic sediment reworking (bulldozing) is an increasing representation of predation- and disturbance-resistant groups in the fossil record. In particular, we observe increasing proportions of mobile organisms; a decline of vulnerable epifauna living freely on the substrate; and a trend toward infaunalization of the benthos. These trends were most pronounced in the paleotropics, i.e., the region where biological activity is thought to have been highest. The observation that these changes affected several biotic traits and occurred within independent clades argues against the overriding role of a single key adaptive innovation in causing shifts in ecological abundance. Also, changes in the abiotic environment cannot explain these faunal patterns because of lacking cross-correlations with physico-chemical parameters such as global sea level, climate, and seawater chemistry. We conclude that in marine benthic ecosystems of the mid Mesozoic, enemy-driven evolution, or escalation, was a plausible and important factor. © 2006 The Paleontological Society. All rights reserved.
UnivIS-Import:2015-04-14:Pub.2006.nat.dgeo.IGM.LP.testin

Tethysocarnia cautica n. gen. n. sp., a sessile foraminifer from Late Ladinian and Carnian reefs of the western and southern Tethys - Senowbari-Daryan, Baba; Flügel, Erik; Preto, Nereo (Geologica et palaeontologica, 2001)
UnivIS-Import:2017-11-07:Pub.2001.nat.dgeo.IGM.LP.tethys

Texture analysis of (Bi,Pb)-2212 in cold isostatic pressed bulk material using the Rietveld method - Risch, Alexander; Gäberlein, Peter; Neubauer, Jürgen; Göbbels, Matthias (European Journal of Mineralogy, 1999)
UnivIS-Import:2015-03-05:Pub.1999.nat.dgeo.IGM.LM.textur

The 2014 water release into the arid Colorado River delta and associated water losses by evaporation - Daessle, L. W.; van Geldern, Robert; Orozco-Duran, A.; Barth, Johannes (Science of the Total Environment, 2016)

The age of the Early Palaeozoic deformation and metamorphism in the Argentine Precordillera - evidence from K/Ar-data - Buggisch, Werner; von Gosen, Werner; Henjes-Kunst, Friedhelm; Krumm, Stefan (Zentralblatt für Geologie und Paläontologie, Teil I, Geologie, 1994)
UnivIS-Import:2015-03-05:Pub.1994.nat.dgeo.IGM.LG.theage

The apparent exponential radiation of Phanerozoic land vertebrates is an artefact of spatial sampling biases - Close, Roger; Benson, Roger; Alroy, John; Carrano, Matthew; Cleary, Terri; Mannion, Phillip; Dunne, Emma; Uhen, Mark; Butler, Richard (Proceedings of the Royal Society of London, Series B: Biological Sciences, 2020)
There is no consensus about how terrestrial biodiversity was assembled through deep time, and in particular whether it has risen exponentially over the Phanerozoic. Using a database of 60 859 fossil occurrences, we show that the spatial extent of the worldwide terrestrial tetrapod fossil record itself expands exponentially through the Phanerozoic. Changes in spatial sampling explain up to 67% of the change in known fossil species counts, and these changes are decoupled from variation in habitable land area that existed through time. Spatial sampling therefore represents a real and profound sampling bias that cannot be explained as redundancy. To address this bias, we estimate terrestrial tetrapod diversity for palaeogeographical regions of approximately equal size. We find that regional-scale diversity was constrained over timespans of tens to hundreds of millions of years, and similar patterns are recovered for major subgroups, such as dinosaurs, mammals and squamates. Although the Cretaceous/Palaeogene mass extinction catalysed an abrupt two- to three-fold increase in regional diversity 66 million years ago, no further increases occurred, and recent levels of regional diversity do not exceed those of the Palaeogene. These results parallel those recovered in analyses of local community-level richness. Taken together, our findings strongly contradict past studies that suggested unbounded diversity increases at local and regional scales over the last 100 million years.<br

THE APPLICABILITY OF TAPHONOMIC BIAS IN LIMESTONES AND MARLS FOR ASSESSING DIAGENETIC LOSS - Nohl, Theresa; Munnecke, Axel; Jarochowska, Emilia (20th International Sedimentological Congress, 2018)

The assembly of Rodinia: The correlation of early Neoproterozoic (ca. 900 Ma) high-grade metamorphism and continental arc formation in the southern Beishan Orogen, southern Central Asian Orogenic Belt (CAOB) - Zong, Keqing; Klemd, Reiner; Yuan, Yu; He, Zhenyu; Guo, Jingliang; Shi, Xiaoli; Liu, Yongsheng; Hu, Zhaochu; Zhang, Zeming (Precambrian Research, 2017)
An early extensive Neoproterozoic (ca. 900 Ma) continental magmatic arc system covering hundreds of kilometers has been reported to occur in the South Beishan Orogenic Belt (SBOB) and the Central Tianshan (CTA) in the southern Central Asian Orogenic Belt (CAOB). However, evidence for coeval high-grade metamorphism and thus the formation of an accretionary orogen in the framework of Rodinia is ambiguous or absent. This study provides new petrological, geochemical and geochronological data for garnet-bearing schists (quartz + garnet + biotite + plagioclase ± muscovite) from the SBOB in order to constrain its Neoproterozoic metamorphic history. The metamorphic zircon rims are either unzoned or display sector zoning in CL-images and reveal REE patterns with flat HREE patterns and negative Eu anomalies, which are interpreted to be in chemical equilibrium with garnet and plagioclase. The zircon U-Pb dating yields concordant U-Pb ages of 900 ± 3 Ma, 897 ± 2 Ma and 898 ± 4 Ma for the metamorphic zircon rims. The inherited detrital zircon cores of one sample display a concordant U-Pb age of 1397 ± 5 Ma that is consistent with the timing of formation for the extensive Mesoproterozoic continental arc in the SBOB and CTA. Based on phase equilibrium geothermobarometry and average P-T thermobarometric calculations, minimum amphibolite-facies P-T conditions are estimated to be >600 °C at pressure >0.6 GPa, which is thought to have been overprinted by subsequent Paleozoic metamorphism. However, the Ti-in-zircon thermometer still reveals temperatures of up to 840 °C using the composition of metamorphic zircon rims, suggesting former ca. 900 Ma granulite-facies peak metamorphic temperatures. The combined petrological and geochronological evidence in conjunction with the continental affinity of the regional metamorphic rocks suggests that the SBOB and the eastern CTA experienced an early Neoproterozoic accretionary orogenesis during the final assembly stage of Rodinia.<br
Keywords: South Beishan Orogenic Belt (SBOB); Central Asian Orogenic Belt (CAOB); Early Neoproterozoic; Continental magmatic arc; Rodinia assembly

The Berill fault and its relation to a Deep Seated Gravitational Slope Deformation (DSGSD) - Krieger, Ingvar; Hermanns, Reginald L.; Schleier, Markus; Yugsi Molina, Freddy Xavier; Oppikofer, Thierry; Rønning, Jan Steinar; Eiken, Trond; Rohn, Joachim (Italian Journal of Engineering Geology and Environment, 2013)
Keywords: Kinematic analyses; Lidar; Normal fault; Rock slope instability; Western norway

The biogeographical imprint of mass extinctions - Kocsis, Ádám; Reddin, Carl James; Kießling, Wolfgang (Proceedings of the Royal Society of London, Series B: Biological Sciences, 2018)
Mass extinctions are defined by extinction rates significantly above background levels and have had substantial consequences for the evolution of life. Geographically selective extinctions, subsequent originations and species redistributions may have changed global biogeographical structure, but quantification of this change is lacking. In order to assess quantitatively the bio-geographical impact of mass extinctions, we outline time-traceable bioregions for benthic marine species across the Phanerozoic using a compositional network. Mass extinction events are visually recognizable in the geographical depiction of bioregions. The end-Permian extinction stands out with a severe reduction of provinciality. Time series of biogeographical turnover represent a novel aspect of the analysis of mass extinctions, confirming concentration of changes in the geographical distribution of benthic marine life.
Keywords: benthic; palaeobiology; mass extinctions; bioregions; networks

The Bongará-Mina Grande (Amazonas, Peru) Zn-nonsulphide deposit - Arfè, Guiseppe; Boni, Maria; Mondillo, Nicola; Ballasone, Pina; Joachimski, Michael; Mormone, Angela (Transactions of the Institutions of Mining and Metallurgy, Section B: Applied Earth Science, 2017)

The Brenzhöhle (Brenz cave) in Königsbronn on the eastern Swabian Alb Die Brenzhöhle in Königsbronn auf der östlichen Schwäbischen Alb - Eckert, Christian; Kempf, Thomas; Eckert, Sabine; López Correa, Matthias (Mitteilungen des Verbandes der Deutschen Höhlen- und Karstforscher, 2021)
The spring of the river Brenz in Königsbronn on the eastern Swabian Alb in Southern Germany presents with a medium discharge of 1336 l/s one of the strongest karstic springs of the Swabian Alb. Just like behind the Aachtopf and Blautopf with their extensive cave systems, a similar underwater cave has long been suspected behind the Brenztopf and was the key target of Germany’s first speleological society, the „Swabian Speleological Society“. Founded in 1889, they built an artificial tunnel to reach the underground lake feeding the Brenz source, but failed. Some 130 years later in 2018, cave divers of the HFGOK could find below a labile entrance an extensive underwater tunnel, with some 300 m explored so far and reaching down to almost 40 m depth below the spring lake. This remarkable cave „Brenzhöhle (7226/63)“is described, along with a first cave map and information on the geological background and karst hydrology.
CRIS-Team Scopus Importer:2024-12-16

The Buckhorn Asphalt deposit – An unique fossil Lagerstätte from the Pennsylvanian of Oklahoma - Seuß, Barbara; Nützel, Alexander; Mapes, Royal H.; Yancey, Thomas E. (GSA, 2008)
The Pennsylvanian Buckhorn Asphalt in Southern Oklahoma contains the best-preserved Palaeozoic mollusc fauna in the world. Early impregnation of mixed carbonatic-siliciclastic rocks (mudstones, pack- to grainstones, shell beds, and conglomerates,) with hydrocarbons prevented aragonite destruction (“Impregnation Fossil Lagerstätte”). 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 Late Palaeozoic deposits. The deposition of the Buckhorn sediments occurred close to a coastal area partly involving mass flow processes (density currents) triggered by storms. Shells of benthic molluscs yield the most diverse known Palaeozoic microboring assemblage, indicating euphotic conditions prior to final deposition. The invertebrate fauna comprises about 155 species and at least 120 genera. The assemblage is strongly dominated by molluscs which is unusual for a Palaeozoic deposit and corroborates that aragonite dissolution produces a major bias in the fossil record. However, most mollusc genera are also known from other Pennsylvanian occurrences (replaced shells). This shows that preservation bias via preferential aragonite dissolution may be overestimate

The Central-Sudetic ophiolites – Remnants of the SSZ-type Devonian oceanic lithosphere in the European part of the Variscan Orogen - Wojtulek, Piotr Marian; Schulz, Bernhard; Klemd, Reiner; Gil, Grzegorz; Dajek, Michał; Delura, Katarzyna (Gondwana Research, 2021)
The Variscan Central-Sudetic Ophiolites (CSO) are located in the Sudetes, the NE segment of the Bohemian Massif. The Devonian CSO display highly depleted, harzburgite mantle sections containing gabbroic dykes and local occurrences of mostly isotropic, large gabbroic bodies as well as volcanic rocks. The ultramafic rocks locally show melt percolation-derived clinopyroxene-olivine aggregates and chromitites. The low REE composition and depletion in LREE relative to HREE of the clinopyroxene as well as the chromite Cr# and Mg# values are typical for phases formed from refractory melts occurring in the supra-subduction zone environment. The gabbroic bodies consist of differently evolved, mostly cumulate rocks, while the volcanic rocks form a relatively monotonous basalt sequence. The trace element compositions of both the plutonic and volcanic rocks display depleted N-MORB affinities, their derivation from a refractory mantle source is further reflected by previously published depleted mantle-like Sr-Nd isotopic compositions. The ultramafic and mafic members of the CSO show greenschist- to lower amphibolite-facies metamorphic overprints. The occurrence of depleted harzburgites and isotropic gabbros forming the mantle and the crustal sections of the CSO, respectively, indicate intermediate- to slow-spreading conditions and a heterogeneous structure of the oceanic lithosphere, untypical for layered ophiolites. The geochemical characteristics of the melt-percolation phases of the ultramafic rocks, the bulk-rock compositions of the mafic rocks and the homogeneous volcanic sequences suggest a formation of the CSO in a mature back-arc basin setting, lacking subduction-derived contamination. Spreading rate conditions and geochemical affinities of the CSO are similar to those of other Devonian ophiolites localized along the Variscan Belt, for instance the Upper Ophiolitic Units in the NW Iberian Massif (Spain), thereby confirming the general absence of N-MORB type lithosphere in the European Variscan Orogen.
CRIS-Team Scopus Importer:2021-10-22
Keywords: Bohemian Massif; Oceanic lithosphere; Ophiolite; Sudetes; Supra-subduction zone; Variscan Orogen

The Central Tianshan Block: A microcontinent with a Neoarchean-Paleoproterozoic basement in the southwestern Central Asian Orogenic Belt - Wang, Xin-Shui; Gao, Jun; Klemd, Reiner; Jiang, Tuo; Li, Jilei; Zhang, Xi; Xue, Shengchao (Precambrian Research, 2017)
The Central Tianshan Block (CTB) is one of the major continental constituents of the western Central Asian Orogenic Belt (CAOB). Its nature and origin is essential for understanding the accretionary processes and the reconstruction of the architectural framework of the CAOB. The Wuwamen Metamorphic Complex (WMC), which is believed to represent the basement of the CTB, was incorporated into the Wuwamen ophiolitic mélange during the Paleozoic evolution of the South Tianshan Ocean. The WMC is mainly composed of amphibolite-facies volcano-sedimentary rocks, including migmatites, orthogneisses, amphibolites, schists and locally marbles. Zircon U–Pb geochronology suggests that the protoliths of the interlayered biotite-two feldspar and biotite-plagioclase-hornblende gneisses in the Yangjuan area were formed between 2529 and 2513 Ma and overprinted by amphibolite-facies metamorphism between 1815 and 1809 Ma. Subsequently, the gneisses were intruded by ∼1724 Ma meta-mafic dykes and ∼787 Ma leucogranite dykes/veins. Geochemical data reveal that the biotite-two feldspar gneisses have high-silica adakite affinities with high SiO2 and Na2O contents as well as high Sr/Y ratios (61–117) and slightly evolved zircon Hf isotopic compositions. Consequently, they are interpreted to be the products of partial melting of relatively old subducted oceanic crust. In contrast, the interlayered biotite-plagioclase-hornblende gneisses have high MgO, Cr, Co and Ni contents and prominent negative Nb–Ta–Ti anomalies, indicating derivation from partial melting of an ancient sub-continental lithospheric mantle in a continental arc setting. The ∼1.72 Ga meta-mafic dykes have geochemical similarities of typical Fe-Ti basalts and are characterized by incompatible element enrichments and primitive Sr–Nd–Hf isotopic signatures ((87Sr/86Sr)i = 0.703446 − 0.703535); ɛNd(t) = +6.49 to +6.90; zircon ɛHf(t) = +0.57 to +10.6), which is consistent with partial melting of a relatively fertile, isotopically depleted asthenospheric mantle in a post-collisional extensional setting. In addition, the ∼787 Ma leucogranites are trondhjemitic in composition and display extremely low total REE contents and highly evolved Nd–Hf isotopic signatures (ɛNd(t) = −4.71 to −4.53; zircon ɛHf(t) = −19.4 to −13.0). They are thought to have no petrogenetic relationship with the host orthogneisses and to be products of a foreign melt injection. Our new data provide robust evidence for a Neoarchean–Paleoproterozoic basement of the CTB. Comparison of the tectono-thermal-magmatic events reveals that the CTB and the Tarim Craton have a partly overlapping Precambrian crustal evolution, and thus the CTB could have originated from the Tarim Craton. However, a major difference between both is the presence of juvenile Mesoproterozoic magmatism in the CTB and its absence in the Tarim Craton and, therefore, further geological and geochronological research is required to determine the precise origin of the CTB and its tectonic affinity with adjacent terranes in the western CAOB.<br
Keywords: Central Tianshan Block; Crustal evolution; Precambrian basement; Tarim Craton; Central Asian Orogenic Belt

The Chicxulub asteroid impact and mass extinction at the Cretaceous-Paleogene boundary - Kießling, Wolfgang; et al. (Science, 2010)
The Cretaceous-Paleogene boundary ∼65.5 million years ago marks one of the three largest mass extinctions in the past 500 million years. The extinction event coincided with a large asteroid impact at Chicxulub, Mexico, and occurred within the time of Deccan flood basalt volcanism in India. Here, we synthesize records of the global stratigraphy across this boundary to assess the proposed causes of the mass extinction. Notably, a single ejecta-rich deposit compositionally linked to the Chicxulub impact is globally distributed at the Cretaceous-Paleogene boundary. The temporal match between the ejecta layer and the onset of the extinctions and the agreement of ecological patterns in the fossil record with modeled environmental perturbations (for example, darkness and cooling) lead us to conclude that the Chicxulub impact triggered the mass extinction.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LAG.thechi

The collision between the Yili and Tarim blocks of the Southwestern Altaids: Geochemical and age constraints of a leucogranite dike crosscutting the HP-LT metamorphic belt in the Chinese Tianshan Orogen. - Gao, Jun; Klemd, Reiner; Qian, Qing; Zhang, Xi; Li, Jilei; Jiang, Tuo; Yang, Yongqiang (Tectonophysics, 2011)
A ca. 600m-long, 0.5-20m-wide NW-SE trending granite dike crosscuts the high pressure-low temperature (HP-LT) Tianshan metamorphic belt, the foliation of which is parallel to the main ENE regional trend in the Chinese South Tianshan Orogen. It is mainly composed of plagioclase, K-feldspar, quartz, muscovite, biotite and secondary chlorite, while fluorite, zircon and xenotime occur as accessories. The immediate country rock is a quartz-biotite-plagioclase schist, which grades several tens of meters away from the granite dike into a chlorite-mica-albite schist. The latter schist is intimately intercalated with blueschist layers and boudins. The A/CNK value of the granite dike samples varies from 1.15 to 1.27 indicating a strongly peraluminous composition. CaO/Na2O ranges from 0.06 to 0.17 and Al2O3/TiO2 from 240 to 525, similar to the ratios of strongly peraluminous (SP) granites exposed in 'high-pressure' collision zones such as the Himalayas. A zircon U-Pb age of 285Ma was obtained for the granite dike, thus constraining the upper limit for the age of HP-LT metamorphism. The petrological and geochemical data suggest that the SP leucogranite dike intruded during the exhumation of overthickened crust in the post-collisional setting between the Yili (-Central Tianshan) and Tarim blocks. The dataset presented here in conjunction with previously published data corroborate that the HP-LT metamorphism must have occurred earlier than the Permian in the Tianshan Orogen. Therefore, the collision between the Yili (-Central Tianshan) and Tarim blocks and the final amalgamation of the Southwestern Altaids must have been terminated in Late Paleozoic and not in Triassic times as previously suggested. © 2011 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.c3geoc.thecol
Keywords: Collision; Leucogranite dike; Southwestern Altaids; Tarim block; Tianshan; Yili block

The cono-dos and cono-dont's of phosphatic microfossil preparation and microanalysis - Shirley, Bryan; Bestmann, Michel; Jarochowska, Emilia (Micron, 2020)
Scanning electron microscope (SEM) imaging of fossils allows unlocking ultrastructural information about their skeletal tissues, but sample preparation of biominerals forming their skeletons requires time, patience, and knowledge. SEM and associated analytical methods allow the observation of internal microstructure, shedding light on function, growth and chemistry. Sample preparation is the process by which material is fixed within a medium (e.g. epoxy resin), a transect created and surface defects removed. This step is arguably the most important in any SEM-based analysis, allowing for the acquisition of reliable, high quality data sets. When conducting any SEM-based technique, the presence of a flat surface is needed to collect consistent and reliable data. Surfaces with topography will both induce charging effects but will also compromise the reliability of data acquired. Techniques from material science are continuously adapted to palaeontological applications, in particular with respect to calcareous microfossils. However, similar studies have not been extensively conducted on bioapatite, owing in part to the difficulties faced in sample preparation alongside its susceptibility to electron beam damage. This case study focuses on conodonts, a marine vertebrate group ranging from the late Cambrian to the Late Triassic. They have been chosen as a model due to the abundance of material, complexity of internal tissues and previous work focused on histological features. With these phosphatic microfossils, we attempt to outline the process of sample preparation and provide information on how to avoid and overcome common pitfalls.
CRIS-Team Scopus Importer:2020-09-04
Keywords: Conodont; Microanalysis; Preparation; Scanning electron microscopy; Ultrastructure

The contexts and early Acheulean archaeology of the EF-HR paleo-landscape (Olduvai Gorge, Tanzania) - de la Torre, Ignacio; Albert, Rosa M.; Macphail, Richard; McHenry, Lindsay J.; Pante, Michael C.; Rodríguez-Cintas, Ágata; Stanistreet, Ian G.; Stollhofen, Harald (Journal of Human Evolution, 2017)
Renewed fieldwork at the early Acheulean site of EF-HR (Olduvai Gorge, Tanzania) has included detailed stratigraphic studies of the sequence, extended excavations in the main site, and has placed eleven additional trenches within an area of nearly 1 km2, to sample the same stratigraphic interval as in the main trench across the broader paleo-landscape. Our new stratigraphic work suggests that EF-HR is positioned higher in the Bed II sequence than previously proposed, which has implications for the age of the site and its stratigraphic correlation to other Olduvai Middle Bed II sites. Geological research shows that the main EF-HR site was situated at the deepest part of an incised valley formed through river erosion. Archaeological excavations at the main site and nearby trenches have unearthed a large new assemblage, with more than 3000 fossils and artefacts, including a hundred handaxes in stratigraphic position. In addition, our test-trenching approach has detected conspicuous differences in the density of artefacts across the landscape, with a large cluster of archaeological material in and around the main trench, and less intense human activity at the same level in the more distant satellite trenches. All of these aspects are discussed in this paper in the light of site formation processes, behavioral contexts, and their implications for our understanding of the early Acheulean at Olduvai Gorge.
Keywords: Bed II chrono-stratigraphy; Early Pleistocene; Early Stone Age; East Africa; Landscape archaeology; Large Cutting Tools

The COSC-2 drill core and its well-preserved lower Palaeozoic sedimentary succession – an unexpected treasure beneath the Caledonian nappes - Lehnert, Oliver; Almqvist, Bjarne; Anderson, Mark; Andersson, Jenny; Cuthbert, Simon; Calner, Mikael; Carter, Isabel; Callegari, Riccardo; Juhlin, Christopher; Lorenz, Henning; Madonna, Claudio; Meinhold, Guido; et al. (Estonian Journal of Earth Sciences, 2024)
The Collisional Orogeny in the Scandinavian Caledonides (COSC) project focuses on processes related to the closure of the Iapetus Ocean, causing the Ordovician–Silurian continent– continent collision between Baltica and Laurentia. The rock succession in the second drill core (COSC-2) from the Jämtland County, central Sweden, provides the base for detailed sedimentological, stratigraphic, geophysical, geochemical, geothermal and structural studies. The basement, comprising 1.66–1.65 Ga Transscandinavian Igneous Belt porphyries intruded by 1.47 Ga and 1.27–1.26 Ga mafic dykes and sills, is heavily weathered towards the top. Here it grades into typical saprock and saprolite (including immature soil reflecting the sub-Cambrian peneplain). The overlying sedimentary sequence starts with basal conglomerates and heterogeneous sediments with shell fragments, indicating an early Cambrian rather than a Neoproterozoic age for the marine transgression in the area. The developing early Cambrian basin was rapidly filled, initially by mostly coarse-grained sediment gravity flows. These strata are covered by sandstone turbidites that show an upward transition into the Alum Shale Formation, representing a tectonically quieter period (mid-Cambrian/Maolingian to Early Ordovician/Tremadocian). The upper part of the Alum Shale Formation is overlain by a late Early Ordovician turbidite succession. Local sources of sediments below the Alum Shale Formation and the extended deposition period may indicate continuous sedimentation in a pull-apart basin preserved in a window beneath the Caledonian thrust sheets.
CRIS-Team Scopus Importer:2024-11-22
Keywords: Baltica; Caledonian Orogen; Cambrian; ICDP; Ordovician; Scandinavian Caledonides (COSC); Sweden

The Cretaceous world: plate tectonics, palaeogeography and palaeoclimate - Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám (Geological Society of London, 2025)
The tectonics, geography and climate of the Cretaceous world were very different from the modern world. At the start of the Cretaceous, the supercontinent of Pangaea had just begun to break apart and only a few small ocean basins separated Laurasia, West Gondwana and East Gondwana. Unlike the modern world, there were no significant continent–continent collisions during the Cretaceous, and the continents were low-lying and easily flooded. The transition from a Pangaea-like configuration to a more dispersed continental arrangement had important effects on the global sea level and climate. During the Early Cretaceous, as the continents rifted apart, the new continental rifts were transformed into young ocean basins. The oceanic lithosphere in these young ocean basins was thermally elevated, which boosted sea level. Sea level, on average, was c. 70 m higher than that of the present day. Sea level was highest during the mid-Cretaceous (90–80 Ma), with a subsidiary peak occurring c. 120 Myr ago (early Aptian). Overall, the Cretaceous was much warmer than the present-day climate (>10°C warmer). These very warm times produced oceanic anoxic events (OAEs), and the high temperatures in equatorial regions sometimes made terrestrial and shallow-marine ecosystems uninhabitable (temperatures >40°C). This is unlike anything we have seen in the last 35 Myr and may presage the eventual results of man-made global warming. This mostly stable, hot climate regime endured for nearly 80 Myr before dramatically terminating with the Chicxulub bolide impact 66 Myr ago. Temperatures plummeted to icehouse levels in the ‘impact winter’ as a result of sunlight-absorbing dust and aerosols being thrown into the atmosphere. As a consequence of the collapse of the food chain, c. 75% of all species were wiped out. The effect of this extinction event on global ecosystems was second only to the great Permo-Triassic Extinction.
CRIS-Team Scopus Importer:2025-04-04

The Cristal Zinc prospect (Amazonas region, northern Peru). Part I: New insights on the sulfide mineralization in the Bongará province - Mondillo, Nicola; Arfè, Giuseppe; Boni, Maria; Ballasone, Pina; Boyce, A; Joachimski, Michael; Kang, J.S.; Villa, I.M. (Ore Geology Reviews, 2018)

The Cristal Zn prospect (Amazonas region, Northern Peru). Part II: An example of supergene enrichments in tropical areas - Arfè, G.; Mondillo, N.; Boni, M.; Joachimski, Michael; Balassone, G.; Mormone, A.; Santoro, L.; Medrano, E. Castro (Ore Geology Reviews, 2018)
Keywords: Bongará; Cristal; Nonsulfides; Paleoclimate; Stable isotopes; Supergene

The Cyclostratigraphy Intercomparison Project (CIP): consistency, merits and pitfalls - Sinnesael, Matthias; De Vleeschouwer, David; Zeeden, Christian; Batenburg, Sietske J.; Da Silva, Anne-Christine; de Winter, Niels J.; Dinarès-Turell, Jaume; Drury, Anna Joy; Gambacorta, Gabriele; Hilgen, Frederik J.; Hinnov, Linda A.; Hudson, Alexander J. L.; et al. (Earth-Science Reviews, 2019)
Cyclostratigraphy is an important tool for understanding astronomical climate forcing and reading geological time in sedimentary sequences, provided that an imprint of insolation variations caused by Earth’s orbital eccentricity, obliquity and/or precession is preserved (Milankovitch forcing). Numerous stratigraphic and paleoclimate studies have applied cyclostratigraphy, but the robustness of the methodology and its dependence on the investigator have not been systematically evaluated. We developed the Cyclostratigraphy Intercomparison Project (CIP) to assess the robustness of cyclostratigraphic methods using an experimental design of three artificial cyclostratigraphic case studies with known input parameters. Each case study is designed to address specific challenges that are relevant to cyclostratigraphy. Case 1 represents an offshore research vessel environment, as only a drill-core photo and the approximate position of a late Miocene stage boundary are available for analysis. In Case 2, the Pleistocene proxy record displays clear nonlinear cyclical patterns and the interpretation is complicated by the presence of a hiatus. Case 3 represents a Late Devonian proxy record with a low signal-to-noise ratio with no specific theoretical astronomical solution available for this age. Each case was analyzed by a test group of 17-20 participants, with varying experience levels, methodological preferences and dedicated analysis time. During the CIP 2018 meeting in Brussels, Belgium, the ensuing analyses and discussion demonstrated that most participants did not arrive at a perfect solution, which may be partly explained by the limited amount of time spent on the exercises (∼4.5 hours per case). However, in all three cases, the median solution of all submitted analyses accurately approached the correct result and several participants obtained the exact correct answers. Interestingly, systematically better performances were obtained for cases that represented the data type and stratigraphic age that were closest to the individual participants’ experience. This experiment demonstrates that cyclostratigraphy is a powerful tool for deciphering time in sedimentary successions and, importantly, that it is a trainable skill. Finally, we emphasize the importance of an integrated stratigraphic approach and provide flexible guidelines on what good practices in cyclostratigraphy should include. Our case studies provide valuable insight into current common practices in cyclostratigraphy, their potential merits and pitfalls. Our work does not provide a quantitative measure of reliability and uncertainty of cyclostratigraphy, but rather constitutes a starting point for further discussions on how to move the maturing field of cyclostratigraphy forward.<br

The development of nutrient pools along two holocene chronosequences with contrasting bedrocks in the Swiss Alps - Greinwald, Konrad; Musso, Alessandra; Scherer-Lorenzen, Michael; Weiler, Markus; Egli, Markus (Catena, 2023)
Climate change accelerates glacial retreat worldwide, leaving large areas of unconsolidated terrain. Glacial retreat opens the possibility to study the temporal development of ecosystems, their functions and services by use of a space-for-time-approach. Nutrient pools are important indicators of various ecosystem services as they are critical in supporting the establishment and growth of plant communities, which in turn support the food webs and ecological processes that sustain the ecosystem and downstream communities. In this study, we examined the temporal development of nutrient pools in soils and vegetation communities over a period of more than 10,000 years. We analyzed a comprehensive dataset that embraces repeated measurements of carbon (C), nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg) and phosphorous (P) pools in above- and belowground biomass, litter and soil across alpine chronosequences from two glacier forelands with contrasting bedrocks (silicate vs carbonate). We found that total nutrient pools of C and N, being closely linked to the biomass, increased rapidly along both chronosequences, whereas nutrient pools of K, Ca, Mg, and P were large at first and decreased steadily with time, though at different rates related to the two parent materials. We also observed a remarkable difference in the P pool development between the two glacier forelands. The calcareous soils started out with much more P than the siliceous locations. The plant availability of P was, however, higher in the siliceous soils due to the neutral pH, but decreased with acidification. In the calcareous soils, plant P availability was low at the beginning due to a high pH, but improved as decalcification progressed and pH lowered to slightly acidic conditions. The results of this work highlight that assessing the temporal development of ecosystems services using long-term proglacial chronosequences enhances our understanding of landscape evolution.
CRIS-Team Scopus Importer:2023-10-06
Keywords: Chronosequence; Glacier foreland; Nutrients; Pedogenesis; Primary succession; Swiss Alps

The Devonian Nekton Revolution - Kießling, Wolfgang; et al. (Lethaia, 2010)
Traditional analyses of Early Phanerozoic marine diversity at the genus level show an explosive radiation of marine life until the Late Ordovician, followed by a phase of erratic decline continuing until the end of the Palaeozoic, whereas a more recent analysis extends the duration of this early radiation into the Devonian. This catch-all approach hides an evolutionary and ecological key event long after the Ordovician radiation: the rapid occupation of the free water column by animals during the Devonian. Here, we explore the timing of the occupation of the water column in the Palaeozoic and test the hypothesis that ecological escalation led to fundamental evolutionary changes in the mid-Palaeozoic marine water column. According to our analyses, demersal and nektonic modes of life were probably initially driven by competition in the diversity-saturated benthic habitats together with the availability of abundant planktonic food. Escalatory feedback then promoted the rapid rise of nekton in the Devonian as suggested by the sequence and tempo of water-column occupation. Devonian, diversity, ecology, food webs, nekton, plankton, radiation. © 2009 The Authors, Journal compilation © 2009 The Lethaia Foundation.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.LP.thedev

The diagenetic destruction of porosity in plutoniclastic petrofacies: The Miocene Diligencia and Eocene Maniobra formations, Orocopia Mountains, southern California, USA - Caracciolo, Luca; et al. (Geological Society of London, 2014)

The Digital Integrated Stratigraphy Project (DISP) - Munnecke, Axel; Cramer, Bradley D.; Boon, David P.; Kharwat, Ranyah; Aiken, Carlos L.; Schofield, David I. (Bulletin of Geosciences, 2012)
The Digital Integrated Stratigraphy Project (DISP) aims to eliminate the stratigraphical ambiguity associated with sam-ple position within a stratigraphical section. For example, it is often impractical or impossible to compare one author's measured section and data precisely against another author's geographically identical measured section and data due to discrepancies in the measured thicknesses of units, variations in the assignments of litho- and chronostratigraphical terms, and/or the precise line of measured sections between authors. The DISP will provide a solution to this problem by producing a precise 3-D digital rendering of the exposure using Terrestrial Laser Scanning (TLS) LiDAR, Real-Time Kinematic (RTK) Global Navigation Satellite Systems (GNSS), overlain digital photography, and GIS software to pro-duce a cm to mm-scale accurate digital version of a given exposure. Once available online as a permanent web-based digital resource for stratigraphy, researchers will be able to access the program and digital models of scanned exposures where they will have the means to log their sample positions directly onto the digital exposure while in the field, thus allow-ing unambiguous stratigraphical reference for future comparison. The Digital Integrated Stratigraphy Project represents the next generation of stratigraphical standard and can serve as the protocol for the future of high-resolution Palaeozoic Earth history research.
Keywords: GSSP; High-resolution; LiDAR; Palaeozoic; Silurian; Stratigraphy; Telychian

The early diversification of ray-finned fishes (Actinopterygii): hypotheses, challenges and future prospects - Henderson, Struan; Dunne, Emma; Fasey, Sophie A.; Giles, Sam (Biological Reviews, 2022)
Actinopterygii makes up half of living vertebrate diversity, and study of fossil members during their Palaeozoic rise to dominance has a long history of descriptive work. Although research interest into Palaeozoic actinopterygians has increased in recent years, broader patterns of diversity and diversity dynamics remain critically understudied. Past studies have investigated macroevolutionary trends in Palaeozoic actinopterygians in a piecemeal fashion, variably using existing compendia of vertebrates or literature-based searches. Here, we present a comprehensive occurrence-based dataset of actinopterygians spanning the whole of the Palaeozoic. We use this to produce the first through-Palaeozoic trends in genus and species counts for Actinopterygii. Diversity through time generally tracks metrics for sampling, while major taxonomic problems pervading the Palaeozoic actinopterygian record obscure diversity trends. Many described species are concentrated in several particularly problematic 'waste-basket' genera, hiding considerable morphological and taxonomic diversity. This taxonomic confusion also feeds into a limited understanding of phylogenetic relationships. A heavy sampling bias towards Europe and North America exists in both occurrence databases and available phylogenetic matrices, with other regions underrepresented despite yielding important data. Scrutiny of the extent to which spatial biases influence the actinopterygian record is lacking, as is research on other forms of bias. Low richness in some time periods may be linked to geological biases, while the effects of taphonomic biases on Palaeozoic actinopterygians have not yet been investigated. Efforts are already underway both to redescribe poorly defined taxa and to describe taxa from underrepresented regions, helping to address taxonomic issues and accuracy of occurrence data. New methods of sampling standardisation utilising up-to-date occurrence databases will be critical in teasing apart biological changes in diversity and those resulting from bias. Lastly, continued phylogenetic work will enable the use of phylogenetic comparative methods to elucidate the origins of actinopterygian biogeography and subsequent patterns of radiation throughout their rise to dominate aquatic faunas.
CRIS-Team WoS Importer:2022-10-21

The early hydration of OPC investigated by in-situ XRD, heat flow calorimetry, pore water analysis and 1H NMR: Learning about adsorbed ions from a complete mass balance approach - Jansen, Daniel; Naber, Christoph; Ectors, Dominique; Lu, Z.; Kong, X. M.; Götz-Neunhoeffer, Friedlinde; Neubauer, Jürgen (Cement and Concrete Research, 2018)
In-situ XRD, heat flow calorimetry, pore water analysis and 1H NMR were used in order to gain more detailed understanding for cement hydration within the first hours of hydration. All methods used show very satisfying accordance. All information gained from the different methods were used in order to calculate absolute mass balance for several ions in order to get an idea about ionic reservoirs adsorbed on surfaces during cement hydration. Sulfate and aluminum adsorption show impact on sulfate depletion, calcium does not.<br
Keywords: Hydration; Calcium silicate; hydrate C-S-H

The early hydration of Ordninary Portland Cement (OPC): An approach comparing measured heat flow with calculated heat flow from QXRD - Jansen, Daniel; Götz-Neunhoeffer, Friedlinde; Lothenbach, Barbara; Neubauer, Jürgen (Cement and Concrete Research, 2011)
Heat flow was calculated from XRD data and compared with measured heat flow from calorimetric experiments. It was shown that the heat released during the hydration of a commercial Ordinary Portland Cement can be assigned mainly to three mechanisms, the silicate reaction (sum of dissolution of alite and precipitation of C-S-H-phase and portlandite), the dissolution of C3A, and the precipitation of ettringite. The contributions made by anhydrite dissolution and gypsum dissolution to the heat released during hydration turned out to be quite small. It is possible to explain, on the basis of the data produced, the origin of the heat flow curve of the cement used.
UnivIS-Import:2015-03-09:Pub.2011.nat.dgeo.IGM.LM.theear
Keywords: X-ray diffraction B; Calorimetry A; Hydration A; Kinetics A; Thermodynamic calculations B

The Early Jurassic Kalkrand Formation. - Stollhofen, Harald; Lorenz, Volker; Gerschütz, Stephan; Stanistreet, Ian G. (IAVCEI Int. Volcanol. Congress Field Excursion C6: Jurassic-Tertiary Volcanism in Southern Namibia,, 1998)
UnivIS-Import:2015-04-20:Pub.1998.nat.dgeo.IGM.LG.theear

The early Katian (Late Ordovician) reefs near Saku, northern Estonia and the age of the Saku Member, Vasalemma Formation. - Kroger, Bjorn; Hints, Linda; Lehnert, Oliver; Mannik, Peep; Joachimski, Michael (Estonian Journal of Earth Sciences, 2014)
Reefs developed simultaneously during the latest Sandbian/earliest Katian global Guttenberg Isotopic Carbon Excursion (GICE) in several places across Baltoscandia. Latest Sandbian/earliest Katian patch reefs are also described from the Vasalemma Formation of northern Estonia. The Saku Member of the Vasalemma Formation was previously considered as a proximal facies related to the reefs. However, the Saku Member clearly post-dates the GICE interval and ranges from the latest Keila to Rakvere in terms of regional stages. Some small reefs occur in direct proximity to the stratotype of the Saku Member. New δ13C data from the stratotype section and the adjacent reefs indicate that these reefs developed before the deposition of the Saku Member during the GICE interval. The chemostratigraphic data support the hypothesis of a short-time Baltoscandian reef growth event that terminated during the GICE interval.
UnivIS-Import:2015-03-09:Pub.2014.nat.dgeo.IGM.LG.theear_6
Keywords: Carbon isotopes; Estonia; GICE excursion; Kope excursion; Oandu Stage; Ordovician reefs

The effect of climate legacies on extinction dynamics: A systematic review - Mathes, Gregor H.; Pimiento, Catalina; Kießling, Wolfgang; Svenning, Jens Christian; Steinbauer, Manuel J. (Cambridge Prisms: Extinction, 2025)
One of the main objectives of ecological research is to enhance our understanding of the processes that lead to species extinction. A potentially crucial extinction pattern is the dependence of contemporary biodiversity dynamics on past climates, also known as climate legacy. However, the general impact of climate legacy on extinction dynamics is unknown. Here, we conduct a systematic review to summarize the effect of climate legacies on extinction dynamics. We find that few works studying the relationship between extinction dynamics and climate include the potential impact of climate legacies (10%), with even fewer studies reaching beyond merely discussing them (3%). Among the studies that quantified climate legacies, six out of seven reported an improved fit of models to extinction dynamics, with most also describing substantial impacts of legacy effects on extinction risk. These include an increase in extinction risk of up to 40% when temperature changes add to a long-term trend in the same direction, as well as substantial effects on species' adaptations, population dynamics and juvenile recruitment. Various ecological processes have been identified in the literature as potential ways in which climate legacies could affect the vulnerability of modern ecosystems to anthropogenic climate change, including niche conservatism, physiological thresholds, time lags and cascading effects. Overall, we find high agreement that climate legacy is a crucial process shaping extinction dynamics. Incorporating climate legacies in biodiversity assessments could be a key step toward a better understanding of the ecological consequences arising from climate change.
CRIS-Team Scopus Importer:2025-06-06
Keywords: Anthropogenic Climate Change; Biodiversity Loss; Climate Legacies; Ecological Mechanisms; Extinction Dynamics

The effect of Cu2+ doping in β-tricalcium phosphate on the hydration mechanism of a brushite cement - Späth, Karla; Götz-Neunhoeffer, Friedlinde; Hurle, Katrin (Materials Today Chemistry, 2023)
Brushite cements show excellent biocompatibility and are therefore an often-used material for bone repair. However, methods to prevent inflammations after surgery are needed. As Cu2+ was proven to provide antibacterial properties, as well as other application relevant features, it is a promising additive. Concerning these factors, a brushite cement containing Cu2+-doped β-tricalcium phosphate, monocalcium phosphate monohydrate, and phytic acid as setting retarder was investigated with powder and in situ X-ray diffraction, isothermal heat flow calorimetry, in situ 1H-time domain – nuclear magnet resonance, and pore solution analysis. The influence of Cu2+ ions on the hydration kinetics of the brushite cement and the locations of the Cu2+ ions after completion of the hydration were the main questions of interest. Heat flow calorimetry showed a significant retardation and deceleration of the hydration with increasing Cu2+ content in β-tricalcium phosphate. This effect can be directly correlated to the Cu2+ ions, as it was also shown for cements without phytic acid. X-ray diffraction showed brushite as main hydrate phase. Additionally, Cu2+-doped cements formed a hydrate phase not assignable by X-ray diffraction, which is assumed to be Cu2+ containing. Furthermore, Cu2+ was detected in the pore solution after the hydration, and no signs of Cu2+ incorporation in the crystal structure of brushite were found.
CRIS-Team Scopus Importer:2022-12-23
Keywords: Copper; Heatflow calorimetry; Phytic acid; X-ray diffraction

The effect of small-scale topography on patterns of endemism within islands - Cutts, Vanessa; Katal, Negin; Löwer, Caroline; Algar, Adam C.; Steinbauer, Manuel; Irl, Severin D. H.; Beierkuhnlein, Carl; Field, Richard (Frontiers of Biogeography, 2019)
Topography influences evolutionary and ecological processes by isolating populations and enhancing habitat diversity. While the effects of large-scale topography on patterns of species richness and endemism are increasingly well documented, the direct effect of local topography on endemism is less understood. This study compares different aspects of topographic isolation, namely the isolating effect of deep barrancos (ravines) and the effect of increasing isolation with elevation in influencing patterns of plant endemism within a topographically diverse oceanic island (La Palma, Canary Islands, Spain). We collected plant presence-absence data from 75 plots in 8 barrancos on the northern coast of La Palma, spanning an elevation gradient from 95 to 674m a.s.l. Using mixed-effects models, we assessed the effect of barranco depth and elevation on the percentage of single-island endemics, multi-island endemics, and archipelago endemics. We found that percent endemism was not significantly correlated with barranco depth and correlated negatively with elevation within barrancos (rather than the expected positive relationship). The topographic barriers associated with the deep island barrancos thus appear insufficient to drive speciation through isolation in oceanic island plants. The decrease in endemism with elevation contradicts findings by previous broader-scale studies and it may reflect local influences, such as high habitat heterogeneity at low elevations.
CRIS-Team Scopus Importer:2021-04-20
Keywords: Barranco; Elevation; Endemism; Islands; Isolation; La palma; Ravine; Topography

The effects of spatial scale and isoscape on consumer isotopic niche width - Reddin, Carl James; Bothwell, John; O'Connor, Nessa; Harrod, Chris (Functional Ecology, 2018)
1. The mean and variance of ecological variables are dependent on sampling attributes such as the coverage of environmental heterogeneity (sampling extent) and spatial scale. Trophic niche width is often approximated by bulk tissue stable isotopes of C and N, that is, the population isotopic niche. However, recent studies suggest that environmental heterogeneity (experienced by individuals) may be more important in defining the isotopic niche width than trophic variability. We hypothesised that isotopic niche width will increase monotonically with spatial scale, largely produced by environmental variation, for example, nutrient source.2. To refine this hypothesis, by describing the shapes of isotope scaling curves, we explored a previously published dataset describing three Chilean intertidal species representing different feeding guilds (grazing snails, suspension-feeding mussel). We tested these hypotheses on a new, larger dataset describing three functionally analogous intertidal species from Northern Ireland. We generated isotopic variance-area curves from a spatially explicit bootstrap and investigated the scale dependency of environment-isotope relationships, including wave exposure and sub-habitat heterogeneity.3. Spatial scale explained 50% of the variance in population isotopic niche widths (bivariate C-N ellipse area) by simple, nonlinear relationships. Finer scales (< 1-10 km lag) accounted for most variance. Scale dependence was strong for delta N-15 variance, of which > 40% was explained by modelling linear coefficients. A delta N-15 baseline gradient, or isoscape, dominated delta N-15 variance scaling patterns, from sheltered, terrestrially influenced embayments to exposed, pelagic-dominated coastline. Consumer delta C-13 variance had a weaker scale dependence, plateauing at mesoscales (> 20 km lag).4. We show that isotopic niche width is strongly dependent on sampling spatial extent, which controls the environmental heterogeneity experienced by individual consumers. Environmental heterogeneity must be accounted for before isotopic niche width can be considered to accurately represent trophic niche width. Studies conducted at different spatial scales are likely to identify different environmentisotope relationships.5. We recommend that spatial scale should be incorporated into sampling designs explicitly, easiest by maintaining a consistent lag distance or area within which populations are sampled. Identified isoscapes can be de-trended, where necessary.
Keywords: ellipse; limpets; marine; mussels; niche space; scale dependence; stable isotope ecology; trophic ecology

The effects of taxonomic standardization on occurrence-based estimates of diversity - Wagner, Peter; Aberhan, Martin; Hendy, Austin; Kießling, Wolfgang (Proceedings of the Royal Society of London, Series B: Biological Sciences, 2007)
UnivIS-Import:2015-03-09:Pub.2007.nat.dgeo.IGM.LP.theeff

The environmental factors limiting the distribution of shallow-water terebratulid brachiopods - Garcia-Ramos, Diego A.; Coric, Stejpan; Joachimski, Michael; Zuschin, Martin (Paleobiology, 2020)

The Evolution and Fossil Record of Parasitism: Coevolution and Paleoparasitological Techniques - de Baets, Kenneth; Huntley, John Warren (Springer, 2021)
This two-volume edited book highlights and reviews the potential of the fossil record to calibrate the origin and evolution of parasitism, and the techniques to understand the development of parasite-host associations and their relationships with environmental and ecological changes. The book deploys a broad and comprehensive approach, aimed at understanding the origins and developments of various parasite groups, in order to provide a wider evolutionary picture of parasitism as part of biodiversity. This is in contrast to most contributions by parasitologists in the literature that focus on circular lines of evidence, such as extrapolating from current host associations or distributions, to estimate constraints on the timing of the origin and evolution of various parasite groups. This approach is narrow and fails to provide the wider evolutionary picture of parasitism on, and as part of, biodiversity. Volume two focuses on the importance of direct host associations and host responses such as pathologies in the geological record to constrain the role of antagonistic interactions in driving the diversification and extinction of parasite-host relationships and disease. To better understand the impact on host populations, emphasis is given to arthropods, colonial metazoans, echinoderms, mollusks and vertebrates as hosts. In addition, novel techniques used to constrain interactions in deep time are discussed ranging from chemical and microscopic investigations of host remains, such as blood and coprolites, to the statistical inference of lateral transfer of transposons and host-parasite coevolutionary dynamics using molecular divergence time estimation.
Keywords: Identifying parasitism in the fossil record; viral fossils; Protistan parasites; Insects as parasitoids and parasites; extinct lineages of parasites; Evolutionary history; Co-divergence; host response; Paleoparasitology techniques; Parasite-induced traces; Molecular perspectives

The Evolution and Fossil Record of Parasitism: Identification and Macroevolution of Parasites - de Baets, Kenneth; Huntley, John Warren (Springer, 2021)
This two-volume edited book highlights and reviews the potential of the fossil record to calibrate the origin and evolution of parasitism, and the techniques to understand the development of parasite-host associations and their relationships with environmental and ecological changes. The book deploys a broad and comprehensive approach, aimed at understanding the origins and developments of various parasite groups, in order to provide a wider evolutionary picture of parasitism as part of biodiversity. This supplements contributions by parasitologists that mostly focus on extrapolating from current host associations or distributions, to estimate constraints on the timing of the origin and evolution of various parasite groups. This approach allows a wider evolutionary picture of parasitism on, and as part of, biodiversity. Volume one focuses on identifying parasitism in the fossil record, and sheds light on the distribution and ecological importance of parasite-host interactions over time. In order to better understand the evolutionary history of parasites and their relationship with changes in the environment, emphasis is given to viruses, bacteria, protista and plants as parasites. Particular attention is given to metazoans such as molluscs, cnidarians, crustaceans and insects as parasites. Researchers, specifically parasitologists, interested in the evolutionary history of parasite-host interactions, as well as students studying parasitism will find this book appealing. <br
Keywords: Bacteria as pathogens; Coprolites; Host responses; Identifying parasitism in the fossil record; Metazoa as parasites; Molecular perspectives; Paleoparasitology techniques; Parasite-induced traces and pathologies; Plants as parasites: Viral fossils

The Evolution of Central Volcanoes in Ultraslow Rift Systems: Constraints From D. João de Castro Seamount, Azores - Romer, René; Beier, C.; Haase, Karsten; Eberts, Andreas; Hübscher, C. (Tectonics, 2021)
The Dom João de Castro seamount in the Hirondelle Basin (Azores) is a central volcano on the ultraslow diverging Terceira Rift axis. The combination of structural and geochemical data provides insights into the evolution of central volcanoes in oceanic rift systems above the Azores melting anomaly. The orientation of fault scarps and volcanic structures at D. João de Castro and the adjacent Castro fissure zone indicate that the regional SW-NE extending stress field dominates the morphology of the NW Hirondelle Basin. The regional tectonic stress field controls the crustal melt pathways and leads to dike emplacement along fissure zones and the prevalent eruption of mafic lavas. The occurrence of mafic to felsic lavas at D. João de Castro gives evidence for both a deep and a shallow crustal melt reservoir generating a subordinate local stress field at the seamount. New Sr-Nd-Pb isotope data along with incompatible trace element ratios indicate that D. João de Castro and the Castro Ridges originated from similarly heterogeneous mantle source but did not form simultaneously. Our new model implies that central volcanoes along the Terceira Rift form by the growth of volcanic ridges and transitioned into circular edifices after magmatic systems generate local changes in the regional lithospheric stress field. The geometry of D. João de Castro and other magmatic systems along the Terceira Rift combined with the alkaline nature of the erupted lavas, and the large lithosphere thickness indicates that young oceanic rifts are more similar to continental rifts rather than mid-ocean ridges.
CRIS-Team Scopus Importer:2021-08-06
Keywords: Azores; central volcano; intraplate volcanism; melt transport; rifting; Terceira Rift

The evolution of the Arabian lower crust and lithospheric mantle - geochemical constraints from southern Syrian mafic and ultramafic xenoliths - Krienitz, Marc-Sebastian; Haase, Karsten (Chemical Geology, 2011)
Geochemical compositions of lower crustal and lithospheric mantle xenoliths found in alkali basaltic lavas from the Harrat Ash Shamah volcanic field in southern Syria place constraints on the formation of the Arabian-Nubian Shield in northern Arabia. Compositions of lower crustal granulites are compatible with a cumulate formation from mafic melts and indicate that they are not genetically related to their host rocks. Instead, their depletion in Nb relative to other incompatible elements points to an origin in a Neoproterozoic subduction zone as recorded by an average depleted mantle Sm-Nd model age of 630. Ma.Lithospheric spinel peridotites typically represent relatively low degree (< 10%) partial melting residues of spinel lherzolite with primitive mantle compositions as indicated by major and trace element modelling of clinopyroxene and spinel. The primary compositions of the xenoliths were subsequently altered by metasomatic reactions with low degree silicate melts and possibly carbonatites. Because host lavas lack these signatures any recent reaction of the lherzolites with their host magma can be ruled out. Sm-Nd data of clinopyroxene from Arabian lithospheric mantle lherzolites yield an average age of 640. Ma suggesting that the lithosphere was not replaced since its formation and supporting a common origin of the Arabian lower crustal and lithospheric mantle sections.The new data along with published Arabian mantle xenolith compositions are consistent with a model in which the lithospheric precursor was depleted oceanic lithosphere that was overprinted by metasomatic processes related to subduction and arc accretion during the generation of the Arabian-Nubian Shield. The less refractory nature of the northern Arabian lithosphere as indicated by higher Al, Na and lower Si and Mg contents of clinopyroxenes compared to the more depleted nature of the south Arabian lithospheric mantle, and the comparable low extent of melt extraction suggest that the northern Arabian lithosphere formed in a continental arc system, whereas the lithosphere in the southern part of Arabia appears to be of oceanic arc origin. © 2010 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2010.nat.dgeo.IGM.legeo.theevo
Keywords: Arabian-Nubian Shield; Continental arc; Granulite; Metasomatism; Peridotite

The explosive-effusive transition within the Miocene Fataga suite, Gran Canaria - Baumann, Nils; Ellis, B. S.; Cortes-Calderon, E. A.; Szymanowski, D.; Harris, C.; Bachmann, O. (Chemical Geology, 2023)
Many volcanoes show transitions between explosive and effusive eruptive styles both through the history of the volcano as a whole and occasionally within the course of a single eruption. These differing eruptive styles have vastly different implications for hazard assessments in surrounding regions and so understanding such changes is important. Here, we investigate the intercalated lavas and ignimbrites of the Miocene Fataga Group on the island of Gran Canaria, Spain. Ignimbrites reflect the products of explosive events from the Tejeda caldera, while lavas found within the pyroclastic succession were erupted from extra-caldera sources some 5–10 km from the caldera margin. The ignimbrites exhibit textural complexity containing both crystal-poor juvenile pyroclasts and late-erupted crystal-rich juvenile clasts interpreted to reflect interaction between cumulates and recharge magmas. The lavas meanwhile are almost phenocryst-free, with the exception of few large (cm-scale), unzoned sanidine crystals. Despite their textural differences, the lavas are geochemically similar (in terms of bulk rock and feldspar compositions) to the crystal-poor juveniles in the ignimbrites. Oxygen and lead isotopic compositions of the lavas and surrounding ignimbrites reveal that the magmas shared a deeper source and that petrographic variability is imprinted upon the magmas at shallow levels. We interpret the lavas as originating from peripheral magmatic pockets, on the edges of the main caldera-feeding reservoir. These peripheral magma chambers felt the effects of recharge only as slight thermal fluctuations that fostered the production of the large sanidine crystals. Our findings highlight the potential for storage of magmas aside from the main magmatic system that may represent an underappreciated hazard at volcanoes worldwide.
CRIS-Team Scopus Importer:2023-01-06
Keywords: Explosive-effusive transition; Gran Canaria; Megacryst; Oxygen isotopes; Pb isotopes

The famous fish beds of Lebanon: the Upper Cretaceous Lagerstätten of Haqel, Hjoula, Nammoura and Sahel Aalma - George, Hady; Bazzi, Mohamad; ElHossny, Tamara; Ashraf, Nida; Abi Saad, Pierre; Clements, Thomas (Journal of the Geological Society, 2024)
The fossils of the Lebanese Upper Cretaceous Lagerstätten, especially the articulated fish, are world renowned. Famous for their soft tissue preservation and highly sought after by fossil collectors, Lebanese fossils provide key information concerning the evolution of several major extant and extinct groups ofMesozoic organisms including cephalopods, crustaceans, hagfish, sharks, marine reptiles and pterosaurs. In fact, fossils from Lebanon are so exceptional that historical documentation describing them extends back to the Roman Empire. However, despite over 1600 years of knowledge of these fossils, a thorough understanding of the depositional environments, taphonomy and palaeoecology of the four main sites, Haqel, Hjoula, Nammoura (each Cenomanian in age) and Sahel Aalma (Santonian), is lacking. Here we compile a review of the palaeoenvironments, fauna and flora of these four Lebanese Lagerstätten. Our synthesis outlines the history of fossil discovery, and describes the current understanding of the geology, ages, mode of preservation and organisms found at these four sites.We also undertake a bibliometric and holotype analysis to investigate the impact that scientific colonialism has had on Lebanon. Our data confirm that local Lebanese researchers are typically not included in publications pertaining to Lebanese fossils and that the majority of Lebanese type material is stored in large historical collections outside Lebanon, predominantly in institutions within the northern hemisphere. Here, we recommend some basic practices for researchers utilizing historical collections that can help develop local Lebanese fossil collections and establish more research opportunities for local palaeontologists.
CRIS-Team Scopus Importer:2024-11-01

The Fermi-LAT Lightcurve Repository - Abdollahi, S.; Ajello, M.; Baldini, Luca; Ballet, J.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Berretta, A.; Bissaldi, E.; Bonino, R.; Brill, A.; Bruel, P.; et al. (Astrophysical Journal Supplement Series, 2023)
The Fermi Large Area Telescope (LAT) lightcurve repository (LCR) is a publicly available, continually updated library of gamma-ray lightcurves of variable Fermi-LAT sources generated over multiple timescales. The Fermi-LAT LCR aims to provide publication-quality lightcurves binned on timescales of 3, 7, and 30 days for 1525 sources deemed variable in the source catalog of the first 10 yr of Fermi-LAT observations. The repository consists of lightcurves generated through full likelihood analyses that model the sources and the surrounding region, providing fluxes and photon indices for each time bin. The LCR is intended as a resource for the time-domain and multimessenger communities by allowing users to search LAT data quickly to identify correlated variability and flaring emission episodes from gamma-ray sources. We describe the sample selection and analysis employed by the LCR and provide an overview of the associated data access portal.
CRIS-Team WoS Importer:2023-05-26

The field-dependence of AC susceptibility in titanomagnetites: Implications for the anisotropy of magnetic susceptibility - de Wall, Helga (Geophysical Research Letters, 2000)

The first Miocene fossils from coastal woodlands in the southern East African Rift - Bobe, René; Aldeias, Vera; Alemseged, Zeresenay; Anemone, Robert L.; Archer, Will; Aumaître, Georges; Bamford, Marion K.; Biro, Dora; Bourlès, Didier L.; Doyle Boyd, Melissa; Braun, David R.; Capelli, Cristian; et al. (iScience, 2023)
The Miocene was a key time in the evolution of African ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here, we report the first Miocene fossil teeth from the shoulders of the Urema Rift in Gorongosa National Park, Mozambique. We provide the first 1) radiometric ages of the Mazamba Formation, 2) reconstructions of paleovegetation in the region based on pedogenic carbonates and fossil wood, and 3) descriptions of fossil teeth. Gorongosa is unique in the East African Rift in combining marine invertebrates, marine vertebrates, reptiles, terrestrial mammals, and fossil woods in coastal paleoenvironments. The Gorongosa fossil sites offer the first evidence of woodlands and forests on the coastal margins of southeastern Africa during the Miocene, and an exceptional assemblage of fossils including new species.
CRIS-Team Scopus Importer:2023-09-15
Keywords: Evolutionary biology; Forestry; Geochemistry

The first record of Early Devonian ammonoids from Belgium and their stratigraphic significance - de Baets, Kenneth; Goolaerts, Stijn; Jansen, Ulrich; Klug, Christian; Rietbergen, Tim (Geologica Belgica, 2013)
The first ammonoids from the Lower Emsian (Devonian) of Belgium are described. They belong to the Anetoceratinae, which show the most plesiomorphic characters of all ammonoids. This is the second report of Early Emsian ammonoids within the Rhenish facies of the Rhenish Slate Mountains (Belgium, Germany), in this case from the Belgian part of the Eifel (Burg Reuland). It highlights the possible importance of ammonoids for the correlation of the Emsian in its traditional German sense and the Emsian in the global sense as delimited by the GSSPs. Newly collected, age-significant brachiopods of the genera Arduspirifer and Euryspirifer and other previously reported fossils indicate a middle or late Early Emsian (Singhofen or Vallendar) age (in German sense) for this locality. We extend the range of Ivoites schindewolfi outside of the Hunsruck Basin and further corroborate an age younger than Ulmen for parts of the Hunsruck Slate.
Keywords: Ammonoidea; Brachiopoda; Early Devonian; Anetoceratinae; Systematics; biostratigraphy