Walliser, Eric-Otto

[["dc.bibliographiccitation.firstpage","532"],["dc.bibliographiccitation.journal","Marine and Petroleum Geology"],["dc.bibliographiccitation.lastpage","541"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Blumenberg, Martin"],["dc.contributor.author","Walliser, Eric-Otto"],["dc.contributor.author","Taviani, Marco"],["dc.contributor.author","Seifert, Richard"],["dc.contributor.author","Reitner, Joachim"],["dc.date.accessioned","2018-11-07T09:52:07Z"],["dc.date.available","2018-11-07T09:52:07Z"],["dc.date.issued","2015"],["dc.description.abstract","Carbonates are widespread at methane and petroleum seeps and are often precipitated as consequence of an alkalinity increase due to the anaerobic oxidation of methane (AOM) or, less often reported, of higher hydrocarbons. These carbonates are taphonomic windows into Earth's history, because they excellently protect the in situ formed microbial signatures (e.g. lipid biomarkers) from diagenetic destruction. A complication for paleoreconstructions, however, is that seep carbonates also encapsulate variable amounts of allochthonous organic matter, sometimes even completely obscuring authigenic microbial signatures. Seep carbonates from the Holocene Black Sea, the Pleistocene Enza River and the Pliocene San Lorenzo (both Northern Apennines, Italy) provide hints to better understand (i) the importance of processes other than AOM for the formation of seep carbonates and (ii) the controls of allochthonous and autochthonous contribution of biomarkers to organic matter in seep carbonates. Biomarker distributions in different parts of a Black Sea carbonate clearly demonstrate that high allochthonous organic matter is entrapped if AOM carbonates are formed intrasedimentary, particularly if methane supply is relatively low and external organic matter input high. High allochthonous contributions were also found in the biomarker inventory of ancient seep carbonates from the Italian Northern Apennines (Enza River and San Lorenzo) pointing at their precipitation within the sediment. Specific and complex conditions were indicated from our data for the Enza River location. Carbonate facies and particularly biomarker compositions, with abundant signatures of sulfate reducing bacteria, suggest that sulfate reduction using alkaline, and eventually sulfate- and higher hydrocarbon-enriched fluids triggered the growth of these seep carbonates. Our and other data suggest that this process has to be more considered if interpreting seep settings, particularly where microbial processes rely on rising fluids from deep petroleum reservoirs. (C) 2015 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.marpetgeo.2015.05.013"],["dc.identifier.isi","000365056000004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36049"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1873-4073"],["dc.relation.issn","0264-8172"],["dc.title","Authigenic carbonate formation and its impact on the biomarker inventory at hydrocarbon seeps - A case study from the Holocene Black Sea and the Plio-Pleistocene Northern Apennines (Italy)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","631"],["dc.bibliographiccitation.journal","Marine and Petroleum Geology"],["dc.bibliographiccitation.lastpage","640"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Wiese, Frank"],["dc.contributor.author","Kiel, Steffen"],["dc.contributor.author","Pack, Andreas"],["dc.contributor.author","Walliser, Eric Otto"],["dc.contributor.author","Agirrezabala, Luis M."],["dc.date.accessioned","2018-11-07T09:52:08Z"],["dc.date.available","2018-11-07T09:52:08Z"],["dc.date.issued","2015"],["dc.description.abstract","An extensive pockmark field with associated methane-seep carbonates has recently been reported from the late Albian (Lower Cretaceous) Ubidepea Mudstone of the Black Flysch Group in the Basque Country, northern Spain, but the exact pathways of the migrating methane-rich fluids remained elusive. Here we provide petrographic, stable carbon and oxygen isotope evidence that abundant crustacean burrows in the surrounding mudstone, preserved as the trace fossil Thalassinoides, and the seep carbonates themselves have acted as long-lasting fluid conduits in this system. The Thalassinoides infill generations show a diagenetic parasequence often starting with a distinctive lining, followed by one to several phases of cementing of the burrow walls and burrow infills, and finally late diagenetic sparry calcite that filled the remaining open cavities and conduits. The micrite cementing the burrow walls shows negative delta C-13 values similar to those reported from the seep carbonates, indicating that methane oxidation was involved in their precipitation, rather than (or in addition to) the oxidation of other organic matter. Even the late diagenetic sparry calcite shows delta C-13 values as low as -30.4 parts per thousand (versus PDB), providing evidence that these burrows served as fluid conduits for an extended period of time. Our study supports the growing body of evidence that crustacean burrows play an important role in channeling seeping fluids in such systems. We anticipate that this phenomenon is much more widespread than currently appreciated, especially in examples where other types of fluid conduits are absent. (C) 2015 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.marpetgeo.2015.03.004"],["dc.identifier.isi","000365056000012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36051"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1873-4073"],["dc.relation.issn","0264-8172"],["dc.title","The beast burrowed, the fluid followed - Crustacean burrows as methane conduits"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","641"],["dc.bibliographiccitation.journal","Marine and Petroleum Geology"],["dc.bibliographiccitation.lastpage","652"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Blumenberg, Martin"],["dc.contributor.author","Walliser, Eric-Otto"],["dc.contributor.author","Schaefer, Nadine"],["dc.contributor.author","Duda, Jan-Peter"],["dc.date.accessioned","2018-11-07T09:52:08Z"],["dc.date.available","2018-11-07T09:52:08Z"],["dc.date.issued","2015"],["dc.description.abstract","Peculiar carbonate bodies occur in distinct marl layers of the Marnes Bleues Formation (Aptian-Albian, Vocontian Basin, Southern France). The carbonate conduits exhibit pipe- or sausage-like forms and a central channel. Their sizes range between 30 and 60 cm in length and 5-10 cm in diameter. The conduit carbonates consist of automicrite authigenically formed within the sediment. Millimeter-sized aggregates of framboidal pyrite are abundant within the conduit automicrites, probably representing former colonies of sulfate reducing bacteria. The central channel reflects former pathways of reduced fluids in the carbonate conduit. Ni-enrichments at the margins of the central cavity are may be due to the activity of methane-related metabolism as Ni is an important bio-element for respective microbes. Light stable carbon isotope ratios of the conduit automicrites (-25.86 parts per thousand, to -23.10 parts per thousand, VPDB) point to carbonate precipitation linked to anaerobic oxidation of methane (AOM), while less depleted stable carbon isotope ratios of microspar in marginal zones of the central opening (-8.96 parts per thousand VPDB) are in line with microbial sulfate reduction. A methane-related origin of the conduit carbonates is confirmed by the presence of authigenic lipid biomarkers tentatively sourced by archaea most of which are characterized by strong C-13 depletions (delta C-13 values down to -104 parts per thousand). The presence of organically bound sulfur is well in line with microbial sulfate reduction. Isorenieratane potentially point to the presence of brown pigmented green sulfur bacteria. The methane was probably sourced by older OAE black shales which are known to contain isotopically (delta C-13) heavy biomarkers of archaea as reported elsewhere. (C) 2015 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.marpetgeo.2015.05.029"],["dc.identifier.isi","000365056000013"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36052"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1873-4073"],["dc.relation.issn","0264-8172"],["dc.title","Methane-derived carbonate conduits from the late Aptian of Salinac (Marne Bleues, Vocontian Basin, France): Petrology and biosignatures"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","542"],["dc.bibliographiccitation.journal","Marine and Petroleum Geology"],["dc.bibliographiccitation.lastpage","554"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Angeletti, L."],["dc.contributor.author","Canese, S."],["dc.contributor.author","Franchi, Fulvio"],["dc.contributor.author","Montagna, Pasquale"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Walliser, Eric Otto"],["dc.contributor.author","Taviani, Marco"],["dc.date.accessioned","2018-11-07T09:52:07Z"],["dc.date.available","2018-11-07T09:52:07Z"],["dc.date.issued","2015"],["dc.description.abstract","A spectacular field of columnar carbonates has been discovered on the Montenegrin margin in the southern Adriatic Sea at a depth of about 450 m. The site exposes many columnar carbonates protruding from the substrate or abated on the bottom. Such carbonates attain maximum visible lengths of ca. 60 cm with diameters up to 20 cm; display an annular growth, and are either hollow or plugged by indurated sediment. Petrographic and geochemical analyses document the pervasive presence of dolomite, and delta C-13 values as low as -30%(0) VPDB. These 'chimneys' are therefore interpreted as former conduits related to hydrocarbon expulsion in this sector of the Adriatic basin. However, available data suggest that hydrocarbon flows at this site have ceased. Our results show that chimneys formed inside the local depositional units, glacial Pleistocene shelf shelly-rich muddy sediment and were successively exhumed from the host sediment. Today, the chimneys offer substrate to benthic life, including cold water corals and sponges. The U-series dating of these carbonate concretions is complicated by the presence of a significant fraction of detrital sediment, which represents a major source of initial Th-230. AMS-C-14 and Sr-87/Sr-86 dating of shells embedded in one of the chimney provided ages beyond the range of radiocarbon dating and <600 kyrs, indicating a Pleistocene age of the host sediment. Uncorrected U-series dating of the carbonate chimneys yielded and age of ca. 250-270 kyrs, providing a temporal upper limit for conduit formation driven by lithification caused by the degradation of seeping hydrocarbons. In addition, U/Th dating of cold water coral bases settled on chimneys indicates a Holocene age for their first exposure after exhumation and subsequent function as hard substrate for benthic organisms. The Montenegrin 'chimney forest' is a rare case where many such carbonate columnar concretions are still in their original vertical position. (C) 2015 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.marpetgeo.2015.04.001"],["dc.identifier.isi","000365056000005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36050"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1873-4073"],["dc.relation.issn","0264-8172"],["dc.title","The \"chimney forest\" of the deep Montenegrin margin, south-eastern Adriatic Sea"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]