Reimer, Andreas

[["dc.bibliographiccitation.journal","Meteoritics & Planetary Science"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Simon, Klaus"],["dc.contributor.author","Sturm, Sebastian"],["dc.contributor.author","Wilk, Jakob"],["dc.contributor.author","Kruppa, Corina"],["dc.contributor.author","Hecht, Lutz"],["dc.contributor.author","Hansen, Bent T."],["dc.contributor.author","Pohl, Jean"],["dc.contributor.author","Reimold, Wolf Uwe"],["dc.contributor.author","Kenkmann, Thomas"],["dc.contributor.author","Jung, Dietmar"],["dc.date.accessioned","2019-07-22T14:26:25Z"],["dc.date.available","2019-07-22T14:26:25Z"],["dc.date.issued","2019"],["dc.description.abstract","The 26 km diameter Nördlinger Ries is a complex impact structure with a ring structure that resembles a peak ring. A first research drilling through this “inner crystalline ring” of the Ries was performed at the Erbisberg hill (SW Ries) to better understand the internal structure and lithology of this feature, and possibly reveal impact‐induced hydrothermal alteration. The drill core intersected the slope of a 22 m thick postimpact travertine mound, before entering 42 m of blocks and breccias of crystalline rocks excavated from the Variscan basement at >500 m depth. Weakly shocked gneiss blocks that show that shock pressure did not exceed 5 GPa occur above polymict lithic breccias of shock stage Ia (10–20 GPa), with planar fractures and planar deformation features (PDFs) in quartz. Only a narrow zone at 49.20–50.00 m core depth exhibits strong mosaicism in feldspar and {102} PDFs in quartz, which are indicative of shock stage Ib (20–35 GPa). Finally, 2 m of brecciated Keuper sediments at the base of the section point to an inverse layering of strata. While reverse grading of clast sizes in lithic breccias and gneiss blocks is consistent with lateral transport, the absence of diaplectic glass and melt products argues against dynamic overthrusting of material from a collapsing central peak, as seen in the much larger Chicxulub structure. Indeed, weakly shocked gneiss blocks are rather of local provenance (i.e., the transient crater wall), whereas moderately shocked polymict lithic breccias with geochemical composition and 87Sr/86Sr signature similar to Ries suevite were derived from a position closer to the impact center. Thus, the inner ring of the Ries is formed by moderately shocked polymict lithic breccias likely injected into the transient crater wall during the excavation stage and weakly shocked gneiss blocks of the collapsing transient crater wall that were emplaced during the modification stage. While the presence of an overturned flap is not evident from the Erbisberg drilling, a survey of all drillings at or near the inner ring point to inverted strata throughout its outer limb. Whether the central ring of the Ries represents remains of a collapsed central peak remains to be shown. Postimpact hydrothermal alteration along the Erbisberg section comprises chloritization, sulfide veinlets, and strong carbonatization. In addition, a narrow zone in the lower parts of the polymict lithic breccia sequence shows a positive Eu anomaly in its carbonate phase. The surface expression of this hydrothermal activity, i.e., the travertine mound, comprises subaerial as well as subaquatic growth phases. Intercalated lake sediments equivalent to the early parts of the evolution of the central crater basin succession confirm a persistent impact‐generated hydrothermal activity, although for less time than previously suggested."],["dc.identifier.doi","10.1111/maps.13293"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61828"],["dc.language.iso","en"],["dc.relation.issn","1086-9379"],["dc.relation.issn","1945-5100"],["dc.title","The Erbisberg drilling 2011: Implications for the structure and postimpact evolution of the inner ring of the Ries impact crater"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1125"],["dc.bibliographiccitation.issue","7-8"],["dc.bibliographiccitation.journal","Geological Society of America Bulletin"],["dc.bibliographiccitation.lastpage","1145"],["dc.bibliographiccitation.volume","125"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Blumenberg, Martin"],["dc.contributor.author","Hansen, Bent Tauber"],["dc.contributor.author","Jung, Dietmar"],["dc.contributor.author","Kolepka, Claudia"],["dc.contributor.author","Lenz, Olaf"],["dc.contributor.author","Nolte, Nicole"],["dc.contributor.author","Poschlod, Klaus"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2018-11-07T09:22:43Z"],["dc.date.available","2018-11-07T09:22:43Z"],["dc.date.issued","2013"],["dc.description.abstract","Scientific drilling conducted at the inner slope of the Miocene central Ries impact crater recovered a partial section of crater lake sediments. Four sequences were recovered, composed of suevite-derived sandstones, thin lignite seams, bituminous shales, and marlstones to claystones. These flooding-evaporation sequences reflect the impact of short-term climatic fluctuations on a hydrologically closed basin. The superimposed trend from sequences rich in bituminous shales in the lower parts of the section to sequences dominated by organic-poor claystones and intercalated lignites in the upper parts of the section resembles that of the 300-m-thick central crater basin succession, which has previously been considered to reflect a climate-controlled development from an alkaline saline lake to a freshwater lake with temporary coal swamps. In the sediment core of Enkingen, however, the change from bituminous shales to organic-poor claystones with intercalated lignites is associated with a general increase in salinity, as indicated by (1) palynomorphs, (2) increase in delta C-13 of the lipid biomarker archaeol (bis-O-phytanylglycerol), and (3) the occurrence of C-13-enriched C-20/C-25-archaeol (O-phytanyl-O-sesterterpanylglycerol) specific to halophilic Archaea. In addition, the unidirectional trend in Sr-87/Sr-86 of carbonates, declining from ratios of Variscan basement rocks toward marine ratios, indicates a change from (1) weathering of crystalline rocks and suevite to (2) ejected Jurassic sediments (Bunte Breccia) in the catchment area as the major source of ion influx to the lake. From that trend, a change in lake water composition and a general increase in ion concentrations are inferred. These new results can be applied to a reassessment of major parts of the lacustrine succession of the Ries crater. We use these data to propose a new hypothetical model for the chemical and ecological evolution of the Ries crater lake: (1) After the establishment of a stratified brackish eutrophic soda lake due to silicate weathering and evaporation, the increasing influx of waters from the Bunte Breccia carbonate and authigenic silicate precipitation led to a mesotrophic halite lake with marine-like ion ratios and concentrations. (2) Further increase in ions, among them Mg2+ and Sr2+, resulted in hypersaline conditions with gypsum precipitation, low primary production, and phreatic Sr-rich do-lomitization in marginal carbonates. (3) The final, sudden change to oligotrophic freshwater conditions is explained by the formation of an outlet late in the lake history. We conclude that the chemical and ecological evolution of the Ries lake therefore appears to have been mainly controlled by the weathering history of the catchment area, with climate fluctuations causing superimposed cycles. Similarly, changes in terrestrial palynomorph associations may at least partly reflect a change in soil types in the catchment area, from fertile, moist soils on suevite to dry karst soils and soils on Bunte Breccia. These interpretations imply that the initial suevite blanket of the Ries crater was much more continuous and widespread than previously assumed."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [AR 335/5, BL 971/1, BL 971/3, Th 713/3]"],["dc.identifier.doi","10.1130/B30731.1"],["dc.identifier.isi","000323270800005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29418"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1943-2674"],["dc.relation.issn","0016-7606"],["dc.title","Chemical and ecological evolution of the Miocene Ries impact crater lake, Germany: A reinterpretation based on the Enkingen (SUBO 18) drill core"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","sed.12888"],["dc.bibliographiccitation.firstpage","2965"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Sedimentology"],["dc.bibliographiccitation.lastpage","2995"],["dc.bibliographiccitation.volume","68"],["dc.contributor.affiliation","Zeng, Lingqi; 1Georg‐August‐Universität Göttingen Geowissenschaftliches Zentrum, Goldschmidtstrasse 3 Göttingen 37077 Germany"],["dc.contributor.affiliation","Ruge, Dag B.; 1Georg‐August‐Universität Göttingen Geowissenschaftliches Zentrum, Goldschmidtstrasse 3 Göttingen 37077 Germany"],["dc.contributor.affiliation","Berger, Günther; 2\r\nSudetenstraße 6 Pleinfeld Germany"],["dc.contributor.affiliation","Heck, Karin; 3Staatliche Naturwissenschaftliche Sammlungen Bayerns ‐ RiesKraterMuseum Nördlingen Eugene‐Shoemaker‐Platz 1 Nördlingen 86720 Germany"],["dc.contributor.affiliation","Hölzl, Stefan; 3Staatliche Naturwissenschaftliche Sammlungen Bayerns ‐ RiesKraterMuseum Nördlingen Eugene‐Shoemaker‐Platz 1 Nördlingen 86720 Germany"],["dc.contributor.affiliation","Reimer, Andreas; 1Georg‐August‐Universität Göttingen Geowissenschaftliches Zentrum, Goldschmidtstrasse 3 Göttingen 37077 Germany"],["dc.contributor.affiliation","Jung, Dietmar; 4Bayerisches Landesamt für Umwelt Geologischer Dienst, Hans‐Högn‐Straße 12 Hof/Saale 95030 Germany"],["dc.contributor.affiliation","Arp, Gernot; 1Georg‐August‐Universität Göttingen Geowissenschaftliches Zentrum, Goldschmidtstrasse 3 Göttingen 37077 Germany"],["dc.contributor.author","Zeng, Lingqi"],["dc.contributor.author","Ruge, Dag B."],["dc.contributor.author","Berger, Günther"],["dc.contributor.author","Heck, Karin"],["dc.contributor.author","Hölzl, Stefan"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Jung, Dietmar"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.editor","Arenas, Concha"],["dc.date.accessioned","2021-08-12T07:45:26Z"],["dc.date.available","2021-08-12T07:45:26Z"],["dc.date.issued","2021"],["dc.date.updated","2022-03-21T04:00:20Z"],["dc.description.abstract","Abstract The identification and distinction of fluvial from lacustrine deposits and the recognition of catchment changes are crucial for the reconstruction of climate changes in terrestrial environments. The investigated drill core succession shows a general evolution from red–brown claystones to white–grey marlstones and microcrystalline limestones, which all have previously been considered as relict deposits of an impact ejecta‐dammed lake, falling within the mid‐Miocene Climate Transition. However, recent mammal biostratigraphic dating suggests a likely pre‐impact age. Indeed, no pebbles from impact ejecta have been detected; only local clasts of Mesozoic formations, in addition to rare Palaeozoic lydites from outside of the study area. Lithofacies analysis demonstrates only the absence of lacustrine criteria, except for one charophyte‐bearing mudstone. Instead, the succession is characterized by less diagnostic floodplain fines with palaeosols, palustrine limestones with root voids and intercalated thin sandstone beds. Carbonate isotope signatures of the mottled marlstones, palustrine limestones and mud‐supported conglomerates substantiate the interpretation of a fluvial setting. Low, invariant δ18Ocarb reflects a short water residence time and highly variable δ13Ccarb indicates a variable degree of pedogenesis. Carbonate 87Sr/86Sr ratios of the entire succession show a unidirectional trend from 0.7103 to 0.7112, indicating a change of the solute provenance from Triassic to Jurassic rocks, identical to the provenance trend from extraclasts. The increase in carbonate along the succession is therefore independent from climate changes but reflects a base‐level rise from the level of the siliciclastic Upper Triassic to the carbonate‐bearing Lower to Middle Jurassic bedrocks. This study demonstrates that, when information on sedimentary architecture is limited, a combination of facies criteria (i.e. presence or absence of specific sedimentary structures and diagnostic organisms), component provenance, and stable and radiogenic isotopes is required to unequivocally distinguish between lacustrine and fluvial sediments, and to disentangle regional geological effects in the catchment and climate influences."],["dc.description.sponsorship","China Scholarship Council http://dx.doi.org/10.13039/501100003398"],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659"],["dc.identifier.doi","10.1111/sed.12888"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/88466"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-448"],["dc.relation.eissn","1365-3091"],["dc.relation.issn","0037-0746"],["dc.rights","This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes."],["dc.title","Sedimentological and carbonate isotope signatures to identify fluvial processes and catchment changes in a supposed impact ejecta‐dammed lake (Miocene, Germany)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Journal of Geophysical Research. E, Planets"],["dc.bibliographiccitation.volume","126"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Dunkl, István"],["dc.contributor.author","Jung, Dietmar"],["dc.contributor.author","Karius, Volker"],["dc.contributor.author","Lukács, Réka"],["dc.contributor.author","Zeng, Lingqi"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Head, James W."],["dc.date.accessioned","2021-06-01T09:41:37Z"],["dc.date.available","2021-06-01T09:41:37Z"],["dc.date.issued","2021"],["dc.identifier.doi","10.1029/2020JE006764"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/84979"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["dc.relation.eissn","2169-9100"],["dc.relation.issn","2169-9097"],["dc.title","A Volcanic Ash Layer in the Nördlinger Ries Impact Structure (Miocene, Germany): Indication of Crater Fill Geometry and Origins of Long‐Term Crater Floor Sagging"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","57"],["dc.bibliographiccitation.journal","Zitteliana: an International Journal of Palaeontology and Geobiology"],["dc.bibliographiccitation.lastpage","94"],["dc.bibliographiccitation.volume","95"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Gropengießer, Sebastian"],["dc.contributor.author","Schulbert, Christian"],["dc.contributor.author","Jung, Dietmar"],["dc.contributor.author","Reimer, Andreas"],["dc.date.accessioned","2022-06-07T14:56:42Z"],["dc.date.available","2022-06-07T14:56:42Z"],["dc.date.issued","2021"],["dc.description.abstract","Extensive construction work at the canal cutting of the Ludwigskanal near Dörlbach, Franconian Alb, provided the opportunity to re-investigate a scientific-historical and biostratigraphically important reference section of the South-German Toarcian. The 16 m thick section, described bed by bed with respect to lithology and macrofossils, starts within the Upper Pliensbachian Amaltheenton Formation, covers the Toarcian Posidonienschiefer and Jurensismergel Formation, and ends in basal parts of the Opalinuston Formation. Carbonate contents are high in the Posidonienschiefer and successively decline within the Jurensismergel to basal parts of the Opalinuston. The high carbonate contents in the Posidonienschiefer are associated with comparatively low organic carbon contents. However, organic carbon contents normalized to the silicate fraction are similarily high if compared to other regions in Germany. Only the persistence of high organic carbon levels into middle parts of the Upper Toarcian differs from those of most regions in central Europe. Ammonite biostratigraphy indicates a thickness of >9 m for the Upper Pliensbachian, 1.15–1.20 m for the Lower Toarcian, 5.04 m for the Upper Toarcian, and >0.5 m for the Lower Aalenian. Despite the low sediment thickness, all Toarcian ammonite zones and almost all subzones are present, except for major parts of the Tenuicostatum Zone and the Fallaciosum Subzone. On the basis of discontinuities, condensed beds, and correlations with neighbouring sections in Southern Germany, a sequence stratigraphic interpretation is proposed for the Toarcian of this region: (i) The Posidonienschiefer Formation corresponds to one 3rd order T-R sequence, from the top of the Hawskerense Subzone to a fucoid bed at the top of the Variabilis Subzone, with a maximum flooding surface at the top of the Falciferum Zone. (ii) The Jurensismergel Formation exhibits two 3rd order T-R sequences: The first ranges from the basis of the Illustris Subzone (i.e., the Intra-Variabilis-Discontinuity) to the top of the Thouarsense Zone, with a maximum flooding surface within the Thouarsense Zone. The “belemnite battlefield” reflects a transgressive “ravinement surface” within the first Jurensismergel Sequence, not a maximum regression surface at its basis. The second sequence extents from the erosive basis of the Dispansum Zone to the top of the Aalensis Subzone, with a maximum flooding surface at the Pseudoradiosa-Aalensis Zone boundary. Finally, the Opalinuston starts with a new sequence at the basis of the Torulosum Subzone. Transgressive system tracts of these 3rd order T-R sequences are commonly phosphoritic, while some regressive system tracts show pyrite preservation of ammonites. The maximum regression surfaces at the basis of the Toarcian and within the Variabilis Zone reflect a significant submarine erosion and relief formation by seawater currents, while this effect is less pronounced at the basis of the Dispansum Zone and basis of the Torulosum Subzone (i.e., the boundary Jurensismergel-Opalinuston Formation)."],["dc.identifier.doi","10.3897/zitteliana.95.56222"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/108749"],["dc.language.iso","en"],["dc.relation.issn","2747-8106"],["dc.relation.issn","2512-5338"],["dc.rights","CC BY 4.0"],["dc.title","Biostratigraphy and sequence stratigraphy of the Toarcian Ludwigskanal section (Franconian Alb, Southern Germany)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Facies"],["dc.bibliographiccitation.volume","63"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Hansen, Bent T."],["dc.contributor.author","Pack, Andreas"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Schmidt, Burkhard C."],["dc.contributor.author","Simon, Klaus"],["dc.contributor.author","Jung, Dietmar"],["dc.date.accessioned","2018-06-28T09:11:52Z"],["dc.date.available","2018-06-28T09:11:52Z"],["dc.date.issued","2016"],["dc.description.abstract","Lacustrine sediments of impact craters form valuable climate archives, although chemical evolution and changes in the catchment area potentially superimpose, distort, or obliterate primary climate signals. The 15 Ma Nördlinger Ries in southern Germany, one of the most intensively studied terrestrial impact structures, harbors a well-preserved but controversially interpreted lacustrine sedimentary fill. While earlier studies proposed a climate-driven development from a playa to a mesosaline soda lake (Units A and B), which then decreased in salinity (Units C and D), new investigations suggest a chemical evolution from a playa and soda lake (Units A–C) to a mesosaline halite lake (Unit D), which then turned into a hypersaline halite lake, until an outlet formed. However, problems in the stratigraphic correlation of basin center and margin sediments impeded the recognition of the hypothetical soda to halite lake transition to date. A new drilling in the central crater now provides a solution for the problem. Unit C still comprises analcime-rich dolomite marl with reversely correlated δ13C and δ18O values, thereby reflecting a shallow, highly alkaline, saline meromictic lake (Na–Mg–CO3–SO4). In turn, Unit D is characterized by a change to cycles composed of lignite, diatomite, claystone, marl, and limestone. Gypsum pseudomorphs at the cycle tops indicate saline lake water (Na–Mg–Cl–SO4) with increased Ca2+ concentrations. Reworked, previously aragonitic, green algal tubes prove that early parts of Unit D sediments formed contemporaneously to basin margin green algal bioherms, contrary to previous assumptions. Therefore, the change from a highly alkaline soda lake to a mesosaline halite lake reflects increasing influx of waters from the Bunte Breccia into the lake, while suevite-derived weathering solutions decreased. Low-salinity conditions during Unit D are temporary phases during lake-level rise at the beginning of short-term cycles, whereas stable oxygen isotope ratios indicate meso- to hypersaline conditions at cycle tops. However, the long-term increase in salinity leading to continuous hypersaline conditions is only preserved in carbonates at the crater rim."],["dc.identifier.doi","10.1007/s10347-016-0483-7"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/15154"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.title","The soda lake—mesosaline halite lake transition in the Ries impact crater basin (drilling Löpsingen 2012, Miocene, southern Germany)"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]