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Herbertingen, Germany

Waas D.,Leibniz Institute for Applied Geophysics | Kleinmann A.,Ritter Eccart Str. 5 | Lepper J.,Ahldener Str. 10 E
Quaternary International | Year: 2011

Peat and other terrestrial sediments are important archives of climate forcing. This study discusses the numerical age determination of stratigraphically important Quaternary sequences from clay pit Nachtigall near Holzminden in northern Germany, which have been the subject of debate concerning their chronological classification since they were first described by Grupe in 1929. Uranium-series dating ( 230Th/U) of different organic horizons as well as sedimentology, including loss-on-ignition (LOI) and palynology was carried out to set up a more reliable chronological framework for the Weser river area. 230Th/U ages were calculated using an isochron approach with the leachate/leachate method for chemical preparation. Open system requirements and specification of sample selection criteria for organic samples are investigated by determination of uranium and thorium composition of the rim layers. Different organic sediments are investigated. The organic deposits from Nachtigall show Middle Pleistocene 230Th/U ages ranging from 227 +9 -8ka to 201 +15 -13ka and appear to represent a warm temperate phase preceding the Eemian Interglacial (MIS 5e) and the Drenthe Stadial (MIS 6), indicating a correlation with marine isotope substage MIS 7c. These results are in good agreement with the investigation of the pollen spectra indicating a correlation with a warm stage within the Lower Saalian Complex. © 2010 Elsevier Ltd and INQUA. Source

Kleinmann A.,Ritter Eccart Str. 5 | Muller H.,Federal Institute for Geosciences and Natural Resources | Lepper J.,Ahldener Str. 10 E | Waas D.,Leibniz Institute for Applied Geophysics
Quaternary International | Year: 2011

The Nachtigall clay pit near Holzminden, northern Germany, is located in a subrosional basin filled with 43 m of interglacial, interstadial and stadial deposits adjacent to the Weser River. The succession separates the Older Middle Terrace from the Younger Middle Terrace of the Weser River. Nachtigall core KB1 (1998) mainly contains silt and clay with intercalated peat layers. The layers of fen peat and intercalated humic silt are between 36 and 22.5 m depth. According to palynological studies, the peat layers and some humic silts were deposited during interglacial and interstadial periods marked by forest vegetation, termed Nachtigall 1 and Nachtigall 2. They are subdivided by a stadial, termed Albaxen. The peat of Nachtigall 1 is interrupted twice by silt and clay strata (Allochthonous Unit I, II) which are reworked sediments of older glacial periods, possibly of late Elsterian or early Holsteinian age. The palynological sequences of Nachtigall and Göttingen/Ottostrasse show the same pattern. Moreover, the contemporaneous pollen profiles of Nachtigall and Göttingen/Ottostrasse can be compared with the Velay pollen sequence (France). The Nachtigall core section 36-26.02 m corresponds to Bouchet 2 - Bonnefond - Bouchet 3 in Velay. The profiles of Velay and Nachtigall are independently correlated to the MIS-timescale and correspond to MIS 7c, 7b, and 7a. TIMS 230Th/U-dating shows ages ranging from 227 + 9/-8 to 201 + 15/-13 ka, which are in good agreement with the inferred MIS 7 age. © 2010 Elsevier Ltd and INQUA. Source

Dorfler W.,University of Kiel | Feeser I.,University of Kiel | van den Bogaard C.,Leibniz Institute of Marine Science | Dreibrodt S.,University of Kiel | And 4 more authors.
Holocene | Year: 2012

The annually laminated record of Lake Belau offers an exceptional opportunity to investigate with high temporal resolution Holocene environmental change, aspects of climate history and human impact on the landscape. A new chronology based on varve counts, 14C-datings and heavy metal history has been established, covering the last 9400 years. Based on multiple varve counting on two core sequences, the easily countable laminated section spans about 7850 varve years (modelled age range c. 9430 to 1630 cal. BP). Not all of the record is of the same quality but approximately 69% of the varves sequence is classified to be of high quality and only c. 5% of low quality. The new chronology suggests dates generally c. 260 years older than previously assumed for the laminated section of the record. The implications for the vegetation and land-use history of the region as well as revised datings for pollen stratigraphical events are discussed. Tephra analysis allowed the identification of several cryptotephra layers. New dates for volcanic eruptions are presented for the Lairg B event (c. 6848 cal. BP, 2σ range 6930-6713 cal. BP), the Hekla 4 event (c. 4396 cal. BP, 2σ range 4417-4266 cal. BP), and Hekla 3 eruption (c. 3095 cal. BP, 2σ range 3120-3068 cal. BP). © The Author(s) 2012. Source

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