TY - JOUR A1 - Rohrmüller, J. A1 - Kämpf, Horst A1 - Geiss, E. A1 - Grossmann, J. A1 - Grun, I. A1 - Mingram, Jens A1 - Mrlina, J. A1 - Plessen, Birgit A1 - Stebich, M. A1 - Veress, C. A1 - Wendt, A. A1 - Nowaczyk, Nobert T1 - Reconnaissance study of an inferred Quaternary maar structure in the western part of the Bohemian Massif near Neualbenreuth, NE-Bavaria (Germany) JF - International journal of earth sciences N2 - After a comprehensive geophysical prospecting the Quaternary MA 1/2 tina Maar, located on a line between the two Quaternary scoria cones Komorni could be revealed by a scientific drilling at the German-Czech border in 2007. Further geophysical field investigations led to the discovery of another geological structure about 2.5 km ESE of the small town Neualbenreuth (NE-Bavaria, Germany), inferred to be also a maar structure, being the fourth volcanic feature aligned along the NW-SE trending Tachov fault zone. It is only faintly indicated as a partial circular rim in the digital elevation model. Though not expressed by a clear magnetic anomaly, geoelectric and refraction seismic tomography strongly indicates a bowl-shaped depression filled with low-resistivity and low-velocity material, correlating well with the well-defined negative gravity anomaly of - 2.5 mGal. Below ca. 15 m-thick debris layer, successions of mostly laminated sediments were recovered in a 100 m-long sediment core in 2015. Sections of finely laminated layers, likely varves, rich in organic matter and tree pollen, were recognized in the upper (22-30 m) and lower (70-86 m) part of the core, respectively, interpreted as interglacials, whereas mostly minerogenic laminated deposits, poor in organic matter, and (almost) barren of tree pollen are interpreted as clastic glacial deposits. According to a preliminary age model based on magnetostratigraphy, palynology, radiocarbon dating, and cyclostratigraphy, the recovered sediments span the time window from about 85 ka back to about 270 ka, covering marine isotope stages 5-8. Sedimentation rates are in the range of 10 cm ka(-1) in interglacials and up to 100 cm ka(-1) in glacial phases. The stratigraphic record resembles the one from MA 1/2 tina Maar, with its eruption date being derived from a nearby tephra deposit at 288 +/- 17 ka, thus supporting the age model of the inferred Neualbenreuth Maar. KW - Eger Rift KW - Quaternary maar volcanism KW - Geophysical prospecting KW - Magnetostratigraphy KW - Palynology KW - Paleoclimate Y1 - 2018 U6 - https://doi.org/10.1007/s00531-017-1543-0 SN - 1437-3254 SN - 1437-3262 VL - 107 IS - 4 SP - 1381 EP - 1405 PB - Springer CY - New York ER - TY - JOUR A1 - Fohlmeister, Jens Bernd A1 - Arps, Jennifer A1 - Spoetl, Christoph A1 - Schroeder-Ritzrau, Andrea A1 - Plessen, Birgit A1 - Günter, Christina A1 - Frank, Norbert A1 - Trüssel, Martin T1 - Carbon and oxygen isotope fractionation in the water-calcite-aragonite system JF - Geochimica et cosmochimica acta : journal of the Geochemical Society and the Meteoritical Society N2 - The precise determination of the stable C and O isotope fractionation between water and calcite (CC) and water and aragonite (AR) is of special interest for climate reconstructions, e.g. paleotemperatures. Previous studies reported results from both laboratory and field experiments, but their results are only partly consistent. Here we present C and O isotope data of a stalagmite from the Swiss Alps, which shows CC-AR transitions along individual growth layers. Using detailed analyses both laterally and perpendicular to such layers we examined the difference in the C and O isotope fractionation factor of the HCO3- - CC and the HCO3- - AR system. For O this difference is similar to the water-CC and water-AR offset provided in experimental studies. The O isotope fractionation difference in the water-CC and water-AR system is comparable to those determined in laboratory studies but shows a statistically significant correlation with the CaCO3 precipitation rate. For C we found a fractionation difference, which is independent of CaCO3 precipitation rate and with slightly smaller values for the fractionation offset between HCO3- - CC and HCO3- - AR compared to literature values. However, we also found an unexpected decrease in delta C-13 along growth layers, which contradicts the widely used concept of Rayleigh fractionation during CO2 degassing and CaCO3 precipitation. The results of this study can be used e.g., to correct stable isotope time series of stalagmites showing CC-AR transitions along their growth axes. (C) 2018 Elsevier Ltd. All rights reserved. Y1 - 2018 U6 - https://doi.org/10.1016/j.gca.2018.05.022 SN - 0016-7037 SN - 1872-9533 VL - 235 SP - 127 EP - 139 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Liu, Qi A1 - Kämpf, Horst A1 - Bussert, Robert A1 - Krauze, Patryk A1 - Horn, Fabian A1 - Nickschick, Tobias A1 - Plessen, Birgit A1 - Wagner, Dirk A1 - Alawi, Mashal T1 - Influence of CO2 degassing on the microbial community in a dry mofette field in Hartoušov, Czech Republic (Western Eger Rift) JF - Frontiers in Microbiology N2 - The Cheb Basin (CZ) is a shallow Neogene intracontinental basin filled with fluvial and lacustrine sediments that is located in the western part of the Eger Rift. The basin is situated in a seismically active area and is characterized by diffuse degassing of mantle-derived CO2 in mofette fields. The Hartousov mofette field shows a daily CO2 flux of 23-97 tons of CO2 released over an area of 0.35 km(2) and a soil gas concentration of up to 100% CO2. The present study aims to explore the geo-bio interactions provoked by the influence of elevated CO2 concentrations on the geochemistry and microbial community of soils and sediments. To sample the strata, two 3-m cores were recovered. One core stems from the center of the degassing structure, whereas the other core was taken 8 m from the ENE and served as an undisturbed reference site. The sites were compared regarding their geochemical features, microbial abundances, and microbial community structures. The mofette site is characterized by a low pH and high TOC/sulfate contents. Striking differences in the microbial community highlight the substantial impact of elevated CO2 concentrations and their associated side effects on microbial processes. The abundance of microbes did not show a typical decrease with depth, indicating that the uprising CO2-rich fluid provides sufficient substrate for chemolithoautotrophic anaerobic microorganisms. Illumine MiSeq sequencing of the 16S rRNA genes and multivariate statistics reveals that the pH strongly influences microbial composition and explains around 38.7% of the variance at the mofette site and 22.4% of the variance between the mofette site and the undisturbed reference site. Accordingly, acidophilic microorganisms (e.g., OTUs assigned to Acidobacteriaceae and Acidithiobacillus) displayed a much higher relative abundance at the mofette site than at the reference site. The microbial community at the mofette site is characterized by a high relative abundance of methanogens and taxa involved in sulfur cycling. The present study provides intriguing insights into microbial life and geo-bio interactions in an active seismic region dominated by emanating mantle-derived CO2-rich fluids, and thereby builds the basis for further studies, e.g., focusing on the functional repertoire of the communities. However, it remains open if the observed patterns can be generalized for different time-points or sites. KW - geo–bio interaction KW - elevated CO2 KW - concentration KW - paleo-sediment KW - deep biosphere KW - acidophilic microorganisms KW - Acidobacteriaceae KW - Acidithiobacillus KW - Acidothermus Y1 - 2018 U6 - https://doi.org/10.3389/fmicb.2018.02787 SN - 1664-302X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Heinrich, Ingo A1 - Balanzategui, Daniel A1 - Bens, Oliver A1 - Blasch, Gerald A1 - Blume, Theresa A1 - Boettcher, Falk A1 - Borg, Erik A1 - Brademann, Brian A1 - Brauer, Achim A1 - Conrad, Christopher A1 - Dietze, Elisabeth A1 - Dräger, Nadine A1 - Fiener, Peter A1 - Gerke, Horst H. A1 - Güntner, Andreas A1 - Heine, Iris A1 - Helle, Gerhard A1 - Herbrich, Marcus A1 - Harfenmeister, Katharina A1 - Heussner, Karl-Uwe A1 - Hohmann, Christian A1 - Itzerott, Sibylle A1 - Jurasinski, Gerald A1 - Kaiser, Knut A1 - Kappler, Christoph A1 - Koebsch, Franziska A1 - Liebner, Susanne A1 - Lischeid, Gunnar A1 - Merz, Bruno A1 - Missling, Klaus Dieter A1 - Morgner, Markus A1 - Pinkerneil, Sylvia A1 - Plessen, Birgit A1 - Raab, Thomas A1 - Ruhtz, Thomas A1 - Sachs, Torsten A1 - Sommer, Michael A1 - Spengler, Daniel A1 - Stender, Vivien A1 - Stüve, Peter A1 - Wilken, Florian T1 - Interdisciplinary Geo-ecological Research across Time Scales in the Northeast German Lowland Observatory (TERENO-NE) JF - Vadose zone journal N2 - The Northeast German Lowland Observatory (TERENO-NE) was established to investigate the regional impact of climate and land use change. TERENO-NE focuses on the Northeast German lowlands, for which a high vulnerability has been determined due to increasing temperatures and decreasing amounts of precipitation projected for the coming decades. To facilitate in-depth evaluations of the effects of climate and land use changes and to separate the effects of natural and anthropogenic drivers in the region, six sites were chosen for comprehensive monitoring. In addition, at selected sites, geoarchives were used to substantially extend the instrumental records back in time. It is this combination of diverse disciplines working across different time scales that makes the observatory TERENO-NE a unique observation platform. We provide information about the general characteristics of the observatory and its six monitoring sites and present examples of interdisciplinary research activities at some of these sites. We also illustrate how monitoring improves process understanding, how remote sensing techniques are fine-tuned by the most comprehensive ground-truthing site DEMMIN, how soil erosion dynamics have evolved, how greenhouse gas monitoring of rewetted peatlands can reveal unexpected mechanisms, and how proxy data provides a long-term perspective of current ongoing changes. Y1 - 2018 U6 - https://doi.org/10.2136/vzj2018.06.0116 SN - 1539-1663 VL - 17 IS - 1 PB - Soil Science Society of America CY - Madison ER -