Zech M.,University of Bayreuth |
Rass S.,University of Bayreuth |
Buggle B.,University of Bayreuth |
Loscher M.,Max Reger Weg 3 |
Zoller L.,University of Bayreuth
Quaternary Research (United States) | Year: 2012
This study contributes to the paleoenvironmental reconstruction of the loess-paleosol sequence of Nussloch, Germany, by using n-alkanes as plant leaf-wax-derived lipid biomarkers. We found that n-alkane patterns and concentrations in the Saalian loess and the last interglacial Eemian paleosol of Nussloch point to very strong degradation and prevailing deciduous vegetation. Degradation effects in the overlying paleosols and loess layers are less pronounced and allow for the application of an end-member mixing model to estimate vegetation changes semi-quantitatively. Our findings highlight the potential for the interpretation of degradation-corrected n-alkane ratios. n-Alkane modelling results for loess layers, paleosols and an in-filled paleochannel dated to ~60-32 ka suggest that up to ~50% of the n-alkanes were derived from deciduous trees or shrubs. This finding is in agreement with the abundant occurrence of wood fragments and indicates a highly variable and dynamic landscape dominated by tundra shrubland. On the other hand, deciduous trees or shrubs did not contribute significantly to the soil organic matter in the late Weichselian loess layers and the intercalated Gelic Gleysols (~32-18 ka). © 2012 University of Washington.
Gocke M.,University of Bayreuth |
Pustovoytov K.,University of Hohenheim |
Kuhn P.,University of Tubingen |
Wiesenberg G.L.B.,University of Bayreuth |
And 2 more authors.
Chemical Geology | Year: 2011
Loess-paleosol sequences are important terrestrial archives for studying Quaternary climate changes. They often contain secondary carbonates including e.g. rhizoliths (calcified roots). These secondary carbonates are precipitated in isotopic equilibrium with root-derived CO2 and are therefore used to reconstruct the vegetation present during their formation based on stable carbon isotopic composition (δ13C). Usually, the chronological context of secondary carbonates in general is not mentioned, because it is assumed that they are formed synsedimentary with loess deposition. The loess-paleosol sequence at Nussloch, SW Germany, contains in its youngest part (Upper Würmian) large carbonate rhizoliths with diameters of up to 5cm and lengths of up to 1m and more, which have not been described in this profile so far. We investigated rhizoliths as well as loess adjacent to and distant from rhizoliths for carbonatic carbon (Ccarb) and organic carbon (Corg) contents, as well as their isotopic composition (δ13C, radiocarbon dating), to identify the rhizolith origin and the time frame of their formation. Considering the 13C fractionation by carbonate precipitation, the δ13Ccarb values (-10.9±0.1‰) revealed C3 plant origin of the rhizolith carbonate and the absence of large amounts of occluded primary loess carbonate. Similar 14C ages of rhizolith Ccarb and Corg (3788±59years BP and 3150±59years BP, respectively) argued for the absence of postsegregational alteration. Therefore they are suitable for the reconstruction of paleoenvironmental conditions after loess sedimentation. The 14C ages clearly indicate that rhizoliths did not form synsedimentary. Roots penetrated the loess at Nussloch after the deposition had ceased at ~15ka BP. Even in the loess adjacent to the rhizoliths (up to a distance of 5cm), δ13Ccarb values indicate the presence of secondary carbonate deriving from postsedimentary organic matter of origin other than that of the reference loess material. Hence, this postsedimentary input of younger root biomass might have masked the initial plant signal in loess-paleosol sequences, which could cause uncertainties for paleoenvironmental reconstructions based solely on loess organic matter. © 2011 Elsevier B.V.
Wagner G.A.,University of Heidelberg |
Maul L.C.,Senckenberg Forschungsinstitute und Naturmuseen |
Loscher M.,Max Reger Weg 3 |
Schreiber H.D.,Staatliches Museum fur Naturkunde Karlsruhe
Quaternary Science Reviews | Year: 2011
The mandible of Homo heidelbergensis was found 1907 in the sand pit Grafenrain at Mauer in coarse fluvial sands 24 m below the surface, deposited in a former course of the Neckar River. These 'Mauer sands' are overlain by a series of glacial-climate loess deposits with intercalated interglacial palaeosols, which can be correlated with Quaternary climate history, thus indicating an early Middle Pleistocene age for H. heidelbergensis. The 'Mauer sands' are famous for their rather rich mammal fauna, which clearly indicates interglacial climate conditions. The faunal evidence - in particular the micromammals - place the 'Mauer sands' into MIS 15 or MIS 13 although most stratigraphic arguments favour correlation to MIS 15 and therefore to an age of ca 600 ka. © 2010 Elsevier Ltd.
Schreiber H.D.,Staatliches Museum of Naturkunde Karlsruhe |
Loscher M.,Max Reger Weg 3
Neues Jahrbuch fur Geologie und Palaontologie - Abhandlungen | Year: 2011
The Grafenrain sand pit N of Mauer near Heidelberg (SW Germany) became famous for the find of the lower jaw of Homo heidelbergensis in October 1907 (SCHOETENSACK 1908). Until the termination of the extractions in 1962 the sand pit yielded a rich and diverse mammalian faunal assemblage. In 2007 new preparation activities connected to the celebrations of the centenary of the hominid lower jaw discovery of Homo heidelbergensis produced samples of sediment (medium gravel) in which an isolated lower cheek tooth of a macaque has been found. The find adduces the presence of Macaca sylvanus in the faunal assemblage of Mauer and represents the second find of a primate from this Pleistocene hominid site. © 2011 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany.