The loess-palaeosol sequence of Datthausen, SW Germany: Characteristics, chronology, and implications for the use of the Lohne Soil as a marker soil

A new loess-palaeosol sequence from the westernmost loess area along the upper Danube River in SW Germany is presented. The profile Datthausen comprises a sequence of Middle Pleniglacial (MPG) and Upper Pleniglacial (UPG) palaeosols, separated by a prominent erosional discontinuity. The uppermost MPG palaeosol consists of two olive-brown horizons, showing morphological characteristics of the “Lohne Soil” that represents the uppermost MPG palaeosol in many loess-palaeosol profiles in the humid loess regions of central Europe. Sedimentological, palaeopedological and micromorphological analyses, combined with luminescence dating, were carried out. Compared to the profiles Nussloch and Schwalbenberg II in the Rhine River region, the profile Datthausen shows more intense pedogenesis, mainly due to its position in a depression and lower loess-accumulation rates. Further, the MPG/UPG transition at Datthausen seems to date later in time, likely matching Greenland interstadial (GIS) 4 and/or GIS 3, rather than GIS 7 to GIS 5. We conclude that the Lohne Soil is a reliable pedostratigraphic marker, whereas its use as a chronometric marker sensu stricto (which should have formed during one well-defined phase of soil formation) is impeded as it evolved during several interstadials. Its use as a chronometric marker sensu lato (which may have formed over several phases of soil formation) is impeded, too, as its chronological position in different loess-palaeosol profiles may not be specific enough. The differences in pedogenesis and chronology between the profiles Nussloch and Schwalbenberg II on one side and the profile Datthausen on the other side are attributed to site-specific factors such as topography. The influence of these factors on pedogenesis at the local scale may prevail over the general climatic regime controlling soil formation at the regional level. Therefore, spatial diversity of palaeosols needs to be considered when matching loess-palaeosol profiles with marine and ice-core records for evaluating the impact of climate forcing on terrestrial palaeoenvironments.