Heim, Christine N.

[["dc.bibliographiccitation.firstpage","715"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","European Journal of Neuroscience"],["dc.bibliographiccitation.lastpage","725"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Heim, Christine"],["dc.contributor.author","Zhang, J."],["dc.contributor.author","Lan, J."],["dc.contributor.author","Sieklucka, M."],["dc.contributor.author","Kurz, Thomas"],["dc.contributor.author","Riederer, Peter"],["dc.contributor.author","Gerlach, M."],["dc.contributor.author","Sontag, K. H."],["dc.date.accessioned","2018-11-07T10:21:47Z"],["dc.date.available","2018-11-07T10:21:47Z"],["dc.date.issued","2000"],["dc.description.abstract","Sixty minutes of cerebral oligaemic hypoxia, induced by bilateral clamping of the carotid arteries (BCCA) in pentobarbital-anaesthetized normotensive rats, induces a late progressive cognitive decline when compared with sham-operated controls. Analysis at BCCA of hippocampal metabolism using microdialysis showed increased release of glutamate, aspartate and gamma-aminobutyric acid, followed by a progressive rise in the formation of hydroxyl free radicals measured as 2,3-dihydroxybenzoic acid (2,3-DHBA), their reaction product with salicylate, though only in the re-perfusion phase. In the striatum increased dopamine release occurred during BCCA, whereas glutamate and aspartate showed an increase only during the late re-perfusion phase. gamma-Aminobutyric acid (GABA) concentration increased during BCCA and early re-perfusion. An increase in 2,3-DHBA was seen during BCCA, and persisted over 2 h of re-perfusion. Six and 13 months after surgery, though not as early as 3 months, BCCA-treated rats perform worse than sham-operated controls in a water-maze, where decreased swimming speed reveals striatal dysfunction, while hippocampal dysfunction manifested as diminished spatial bias. These results show that cerebral oligaemia, similarly to cerebral ischaemia, leads to increased extracellular dopamine, aspartate and glutamate, and the production of hydroxyl radicals in structures associated with learning and memory processes. Unlike cerebral ischaemia, in cerebral oligaemia the appearance of spatial memory deficits is delayed."],["dc.identifier.doi","10.1046/j.1460-9568.2000.00916.x"],["dc.identifier.isi","000085927900031"],["dc.identifier.pmid","10712651"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42158"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Blackwell Science Ltd"],["dc.relation.issn","0953-816X"],["dc.title","Cerebral oligaemia episode triggers free radical formation and late cognitive deficiencies"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","13"],["dc.bibliographiccitation.journal","Geochimica et Cosmochimica Acta"],["dc.bibliographiccitation.volume","73"],["dc.contributor.author","Heller, C."],["dc.contributor.author","Blumenberg, Martin"],["dc.contributor.author","Dreier, Anne"],["dc.contributor.author","Wrede, Christoph"],["dc.contributor.author","Zilla, Thomas"],["dc.contributor.author","Kokoschka, Sebastian"],["dc.contributor.author","Heim, C."],["dc.contributor.author","Hoppert, Michael"],["dc.contributor.author","Taviani, M."],["dc.contributor.author","Reitner, Joachim"],["dc.date.accessioned","2018-11-07T08:29:13Z"],["dc.date.available","2018-11-07T08:29:13Z"],["dc.date.issued","2009"],["dc.identifier.isi","000267229901266"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16598"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.publisher.place","Oxford"],["dc.relation.conference","19th Annual VM Goldschmidt Conference"],["dc.relation.eventlocation","Davos, SWITZERLAND"],["dc.title","First results of geo- and biochemical analyses of terrestrial methane-emittingen mud volcanoes in Italy"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","237"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Geobiology"],["dc.bibliographiccitation.lastpage","251"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Reinhardt, Manuel"],["dc.contributor.author","Duda, Jan-Peter"],["dc.contributor.author","Blumenberg, Martin"],["dc.contributor.author","Ostertag-Henning, Christian"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Heim, Christine N."],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2019-07-22T14:14:22Z"],["dc.date.available","2019-07-22T14:14:22Z"],["dc.date.issued","2018"],["dc.description.abstract","Fossil derivatives of isorenieratene, an accessory pigment in brown-colored green sulfur bacteria, are often used as tracers for photic zone anoxia through Earth's history, but their diagenetic behavior is still incompletely understood. Here, we assess the preservation of isorenieratene derivatives in organic-rich shales (1.5-8.4 wt.% TOC) from two Lower Jurassic anoxic systems (Bächental oil shale, Tyrol, Austria; Posidonia Shale, Baden-Württemberg, Germany). Bitumens and kerogens were investigated using catalytic hydropyrolysis (HyPy), closed-system hydrous pyrolysis (in gold capsules), gas chromatography-mass spectrometry (GC-MS) and gas chromatography combustion isotope ratio-mass spectrometry (GC-C-IRMS). Petrography and biomarkers indicate a syngenetic relationship between bitumens and kerogens. All bitumens contain abundant isorenieratane, diverse complex aromatized isorenieratene derivatives, and a pseudohomologous series of 2,3,6-trimethyl aryl isoprenoids. In contrast, HyPy and mild closed-system hydrous pyrolysis of the kerogens yielded only minor amounts of these compounds. Given the overall low maturity of the organic matter (below oil window), it appears that isorenieratene and its abundant derivatives from the bitumen had not been incorporated into the kerogens. Accordingly, sulfur cross-linking, the key mechanism for sequestration of functionalized lipids into kerogens in anoxic systems, was not effective in the Jurassic environments studied. We explain this by (i) early cyclization/aromatization and (ii) hydrogenation reactions that have prevented effective sulfurization. In addition, (iii) sulfide was locally removed via anoxygenic photosynthesis and efficiently trapped by the reaction with sedimentary iron, as further indicated by elevated iron contents (4.0-8.7 wt.%) and the presence of abundant pyrite aggregates in the rock matrix. Although the combined processes have hampered the kerogen incorporation of isorenieratene and its derivatives, they may have promoted the long-term preservation of these biomarkers in the bitumen fraction via early defunctionalization. This particular taphonomy of aromatic carotenoids has to be considered in studies of anoxic iron-rich environments (e.g., the Proterozoic ocean)."],["dc.identifier.doi","10.1111/gbi.12284"],["dc.identifier.pmid","29569335"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61823"],["dc.language.iso","en"],["dc.relation.eissn","1472-4669"],["dc.relation.issn","1472-4677"],["dc.relation.orgunit","Abteilung Geobiologie"],["dc.title","The taphonomic fate of isorenieratene in Lower Jurassic shales-controlled by iron?"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1353"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Biological Invasions"],["dc.bibliographiccitation.lastpage","1363"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","Nielsen, Charlotte"],["dc.contributor.author","Heimes, Christine"],["dc.contributor.author","Kollmann, Johannes"],["dc.date.accessioned","2018-11-07T11:08:21Z"],["dc.date.available","2018-11-07T11:08:21Z"],["dc.date.issued","2008"],["dc.description.abstract","Many invasive alien plants occur in large populations with abundant flowers which are highly attractive to pollinators, and thus might affect pollination of co-occurring native species. This study focuses on the invasive Heracleum mantegazzianum and distance-dependent effects on pollination of Mimulus guttatus in abandoned grassland over 2 years. First, we examined pollinator abundance in yellow traps at 0, 10, 30 and 60-200 m from H. mantegazzianum. We then placed M. guttatus plants at the same distances to monitor effects of the invasive species on pollinator visitation and seed set of neighbouring plants. Finally, we conducted a garden experiment to test if deposition of H. mantegazzianum pollen reduces seed set in M. guttatus. No distance effect was found for the number of bumblebees in traps, although the invasive species attracted a diverse assemblage of insects, and visitation of M. guttatus was enhanced close to H. mantegazzianum. This positive effect was not reflected by seed set of M. guttatus, and heterospecific pollen decreased seed set in these plants. Overall there is little evidence for negative effects of the invasive species on pollination of neighbouring plants, and flower visitation even increases close to the invaded patches. The functional role of the invader and suitable control strategies need further clarification, since removal of H. mantegazzianum may actually damage local pollinator populations."],["dc.description.sponsorship","University of Copenhagen; Paul + Maria Kremer-Stiftung"],["dc.identifier.doi","10.1007/s10530-007-9210-1"],["dc.identifier.isi","000260306700016"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52755"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","1387-3547"],["dc.title","Little evidence for negative effects of an invasive alien plant on pollinator services"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","207"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Geomicrobiology Journal"],["dc.bibliographiccitation.lastpage","220"],["dc.bibliographiccitation.volume","32"],["dc.contributor.author","Ionescu, Danny"],["dc.contributor.author","Heim, Christine"],["dc.contributor.author","Polerecky, Lubos"],["dc.contributor.author","Ramette, Alban"],["dc.contributor.author","Haeusler, Stefan"],["dc.contributor.author","Bizic-Ionescu, Mina"],["dc.contributor.author","Thiel, Volker"],["dc.contributor.author","De Beer, Dirk"],["dc.date.accessioned","2018-11-07T09:59:33Z"],["dc.date.available","2018-11-07T09:59:33Z"],["dc.date.issued","2015"],["dc.description.abstract","Processes of iron mineralization are of great significance to the understanding of Early-Earth geochemistry. Of specific interest are processes at circumneutral pH, where chemical oxidation of Fe can outcompete biological oxidation. To better understand microbially-induced mineral formation and the composition of the involved microbial communities, we set up a series of flow-reactors in the aspo Hard Rock Laboratory, a 3.6km tunnel that runs under the Baltic Sea. Various aquifers of Fe2+-rich brackish to saline waters penetrate the tunnel through a series of fractions. The reactors were set up with different combinations of light and aeration conditions, and were connected to three aquifers of differing chemical composition and age. Using a combination of 454 pyrosequencing and CAtalyzed Reporter Deposition Fluorescent In Situ Hybridization we analyzed the bacterial community from these reactors in two consecutive seasons half a year apart. A general decrease in diversity was observed towards the deep part of the tunnel. Multivariate modeling of the community composition and environmental parameters shows that the overall diversity of the microbial community is controlled by salinity as well as carbon and nitrogen sources. However, the composition of iron oxidizing bacteria is driven by pH, O-2 and the availability of Fe2+. The latter is mostly supplied by Fe3+ reduction in the reactors. Thus the reactors form a self-sustained ecosystem. Several genera of known aerobic and anaerobic iron oxidizing bacteria were found. Mariprofundus sp. was found to be dominant in many of the samples. This is the first detection of this marine species in groundwater. The microbial community in the reactors is unique in each site, while that in the exposed tunnel is more homogenous. Therefore we suggest that the flow reactors are a good model system to study the nonaccessible microbial communities that are likely present in cracks and crevices of the surrounding bedrock."],["dc.description.sponsorship","German Research Foundation (DFG)"],["dc.identifier.doi","10.1080/01490451.2014.884196"],["dc.identifier.isi","000352349600003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37617"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1521-0529"],["dc.relation.issn","0149-0451"],["dc.title","Diversity of Iron Oxidizing and Reducing Bacteria in Flow Reactors in the aspo Hard Rock Laboratory"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","23"],["dc.bibliographiccitation.journal","Organic Geochemistry"],["dc.bibliographiccitation.lastpage","33"],["dc.bibliographiccitation.volume","57"],["dc.contributor.author","Leefmann, Tim"],["dc.contributor.author","Heim, Christine"],["dc.contributor.author","Kryvenda, Anastasiia"],["dc.contributor.author","Siljestrom, Sandra"],["dc.contributor.author","Sjovall, Peter"],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2018-11-07T09:26:25Z"],["dc.date.available","2018-11-07T09:26:25Z"],["dc.date.issued","2013"],["dc.description.abstract","Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a surface sensitive MS technique that offers a new way of studying lipid biomarkers at the microscopic level, without the need to destroy the physical integrity of the sample by extraction. We applied ToF-SIMS to a cryosection of a microbial mat and compared the results with ToF-SIMS and gas chromatography-MS (GC-MS) analysis of extracts from the same material. A wide range of lipid biomarkers was identified with ToF-SIMS in the microbial mat cryosection. Spectra and ion images revealed that individual biomarkers, including fatty acids, mono-, di- and triacylglycerols, carotenoids and chlorophyll were localized with diatom cells identified as Planothidium lanceolatum using optical microscopy. This diatom species can thus be regarded as a major lipid source within the microbial mat system. The results underpin the idea that ToF-SIMS has the potential to become an important technique for future biomarker studies, in particular for the clear cut assignment of biomarkers to distinctive morphological structures and specific microorganisms within complex biogeochemical samples. (c) 2013 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.orggeochem.2013.01.005"],["dc.identifier.isi","000318074500004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/30294"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0146-6380"],["dc.title","Biomarker imaging of single diatom cells in a microbial mat using time-of-flight secondary ion mass spectrometry (ToF-SIMS)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","221"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Geomicrobiology Journal"],["dc.bibliographiccitation.lastpage","230"],["dc.bibliographiccitation.volume","32"],["dc.contributor.author","Ionescu, Danny"],["dc.contributor.author","Heim, Christine"],["dc.contributor.author","Polerecky, Lubos"],["dc.contributor.author","Thiel, Volker"],["dc.contributor.author","De Beer, Dirk"],["dc.date.accessioned","2018-11-07T09:59:34Z"],["dc.date.available","2018-11-07T09:59:34Z"],["dc.date.issued","2015"],["dc.description.abstract","Oxidation and reduction of iron can occur through abiotic (chemical) and biotic (microbial) processes. Abiotic iron oxidation is a function of pH and O-2 concentration. Biotic iron oxidation is carried out by a diverse group of bacteria, using O-2 or NO3 as terminal electron acceptors. At circumneutral pH, both processes occur at similar rates and compete with each other. Abiotic iron reduction is catalyzed by iron-sulfur minerals or different types of organic compounds, whereas biotic iron reduction is carried out by a diverse group of microorganisms, often using chemical agents to dissolve solid iron minerals. We used iron oxidizing microbial mats to assess the potential impact of microbial activity on the deposition of banded iron formations (BIF). The mats were collected during several years from experimental tanks connected to groundwater aquifers with different Fe2+ concentrations. To separate between biotic and abiotic iron oxidation, live and killed mats were incubated with Fe-57(2+). Separate analyses of the water and solid phase revealed that the iron oxidation and reduction rates per mL of solid matter (biomass and iron precipitates) were 0.4-73mmol L-1 d(-1) and 30-280mmol L-1 d(-1), respectively. No significant differences in iron oxidation rates were observed between the live and killed samples. The iron reduction rates, however, were higher in the live samples in mats from 3 out of 4 environments. We suggest that in natural systems, in the presence of organic matter, biotic and abiotic iron oxidation and reduction are not separable processes. Fe2+ will be biotically and abiotically oxidized as well as bind to exposed charged groups of organic substances. Either way, this iron may serve as a nucleation matrix for further abiotic iron precipitation. The oxidized iron is then susceptible to iron reduction, which can likewise be a direct metabolic or an abiotic process. Nevertheless, it is important to note the significance of organic matter, since both the abiotic oxidation and reduction of iron are often mediated by substrates of biological origin."],["dc.description.sponsorship","German Research Foundation (DFG)"],["dc.identifier.doi","10.1080/01490451.2014.887393"],["dc.identifier.isi","000352349600004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37619"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1521-0529"],["dc.relation.issn","0149-0451"],["dc.title","Biotic and abiotic oxidation and reduction of iron at circumneutral pH are inseparable processes under natural conditions"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2741"],["dc.bibliographiccitation.issue","17"],["dc.bibliographiccitation.journal","Rapid Communications in Mass Spectrometry"],["dc.bibliographiccitation.lastpage","2753"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Heim, Christine"],["dc.contributor.author","Sjovall, Peter"],["dc.contributor.author","Lausmaa, Jukka"],["dc.contributor.author","Leefmann, Tim"],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2018-11-07T11:25:28Z"],["dc.date.available","2018-11-07T11:25:28Z"],["dc.date.issued","2009"],["dc.description.abstract","In recent years, time-of-flight secondary ion mass spectrometry (ToF-SIMS) with cluster ion sources has opened new perspectives for the analysis of lipid biomarkers in geobiology and organic geochemistry. However, published ToF-SIMS reference spectra of relevant compounds are still sparse, and the influence of the chemical environment (matrix) on the ionisation of molecules and their fragmentation is still not well explored. This study presents ToF-SIMS spectra of eight glycerolipids as common target compounds in biomarker studies, namely ester- and ether-bound phosphatidylethanolamine, ester- and ether-bound phosphatidylcholine, ester-bound phosphatidylglycerol, ester- and ether-bound diglycerides and archaeol, obtained with a Bi(3)(+) cluster ion source. For all of these compounds, the spectra obtained in positive and negative analytical modes showed characteristic fragments that could clearly be assigned to e.g. molecular ions, functional groups and alkyl chains. By comparison with the reference spectra, it was possible to track some of these lipids in a pre-characterised organic extract and in cryosections of microbial mats. The results highlight the potential of ToF-SIMS for the laterally resolved analysis of organic biomarkers in environmental materials. The identification of the target compounds, however, may be hampered by matrix effects (e.g. adduct formation) and often require careful consideration of all spectral features and taking advantage of the molecular imaging capability of ToF-SIMS. Copyright (C) 2009 John Wiley & Sons, Ltd."],["dc.identifier.doi","10.1002/rcm.4183"],["dc.identifier.isi","000269280300019"],["dc.identifier.pmid","19639617"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/56629"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0951-4198"],["dc.title","Spectral characterisation of eight glycerolipids and their detection in natural samples using time-of-flight secondary ion mass spectrometry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","13"],["dc.bibliographiccitation.journal","Geochimica et Cosmochimica Acta"],["dc.bibliographiccitation.volume","73"],["dc.contributor.author","Heim, Christine"],["dc.contributor.author","Lausmaa, Jukka"],["dc.contributor.author","Sjovall, Peter"],["dc.contributor.author","Simon, Klaus"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2018-11-07T08:29:13Z"],["dc.date.available","2018-11-07T08:29:13Z"],["dc.date.issued","2009"],["dc.identifier.isi","000267229901256"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16597"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.publisher.place","Oxford"],["dc.relation.conference","19th Annual VM Goldschmidt Conference"],["dc.relation.eventlocation","Davos, SWITZERLAND"],["dc.title","Traces of a fossil deep biosphere in fracture fillings of the Aspo Diorite (Sweden)"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","556"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Geobiology"],["dc.bibliographiccitation.lastpage","574"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Drake, Henrik"],["dc.contributor.author","Whitehouse, Martin J."],["dc.contributor.author","Heim, Christine"],["dc.contributor.author","Reiners, Peter W."],["dc.contributor.author","Tillberg, Mikael"],["dc.contributor.author","Hogmalm, K. Johan"],["dc.contributor.author","Dopson, Mark"],["dc.contributor.author","Broman, Curt"],["dc.contributor.author","Astrom, Mats E."],["dc.date.accessioned","2019-07-22T14:49:06Z"],["dc.date.available","2019-07-22T14:49:06Z"],["dc.date.issued","2018"],["dc.description.abstract","In the deep biosphere, microbial sulfate reduction (MSR) is exploited for energy. Here, we show that, in fractured continental crystalline bedrock in three areas in Sweden, this process produced sulfide that reacted with iron to form pyrite extremely enriched in 34 S relative to 32 S. As documented by secondary ion mass spectrometry (SIMS) microanalyses, the δ34 Spyrite values are up to +132‰V-CDT and with a total range of 186‰. The lightest δ34 Spyrite values (-54‰) suggest very large fractionation during MSR from an initial sulfate with δ34 S values (δ34 Ssulfate,0 ) of +14 to +28‰. Fractionation of this magnitude requires a slow MSR rate, a feature we attribute to nutrient and electron donor shortage as well as initial sulfate abundance. The superheavy δ34 Spyrite values were produced by Rayleigh fractionation effects in a diminishing sulfate pool. Large volumes of pyrite with superheavy values (+120 ± 15‰) within single fracture intercepts in the boreholes, associated heavy average values up to +75‰ and heavy minimum δ34 Spyrite values, suggest isolation of significant amounts of isotopically light sulfide in other parts of the fracture system. Large fracture-specific δ34 Spyrite variability and overall average δ34 Spyrite values (+11 to +16‰) lower than the anticipated δ34 Ssulfate,0 support this hypothesis. The superheavy pyrite found locally in the borehole intercepts thus represents a late stage in a much larger fracture system undergoing Rayleigh fractionation. Microscale Rb-Sr dating and U/Th-He dating of cogenetic minerals reveal that most pyrite formed in the early Paleozoic era, but crystal overgrowths may be significantly younger. The δ13 C values in cogenetic calcite suggest that the superheavy δ34 Spyrite values are related to organotrophic MSR, in contrast to findings from marine sediments where superheavy pyrite has been proposed to be linked to anaerobic oxidation of methane. The findings provide new insights into MSR-related S-isotope systematics, particularly regarding formation of large fractions of 34 S-rich pyrite."],["dc.identifier.doi","10.1111/gbi.12297"],["dc.identifier.pmid","29947123"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61836"],["dc.language.iso","en"],["dc.relation.eissn","1472-4669"],["dc.relation.issn","1472-4677"],["dc.title","Unprecedented 34 S-enrichment of pyrite formed following microbial sulfate reduction in fractured crystalline rocks"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]