Abstract
The complex interplay of dust sedimentation, pedogenesis, and erosion/reworking in the formation of loess-paleosol sequences (LPS) challenges paleoenvironmental proxies. Here we show that color and grain size are essential parameters characterizing loess profiles and support robust stratigraphies as a basis for reconstructions in the context of local geo-ecological and large-scale paleoclimatic evolution. Detailed paleoenvironmental records from the period since the arrival of anatomically modern humans to the last glacial maximum are scarce in the Alpine surroundings. The c. 7.5 m thick LPS Krems-Wachtberg, NE Austria, known for its well-preserved Upper Paleolithic context at a depth of 5.5 m, formed between 40 and 20 ka BP by quasi-continuous dust-sedimentation, interrupted by phases of incipient pedogenesis and local reworking. The new KW2015 composite is based on three sections studied and sampled at 2.5 cm resolution. Color and grain size data support a robust stratigraphy for reconstructions of the pedosedimentary evolution. The marked transition from oxidized to reduced paleosols of KW2015 around 34–35 ka corresponds to the Middle-to Upper Pleniglacial transition as part of a general cooling trend from marine isotope stage (MIS) 3 to 2, intensely modulated by millennial-scale climatic fluctuations as recorded in the Greenland ice core data. The distinct response of KW2015 to these trends highlights that reconstructing LPS evolution based on a robust stratigraphy is a prerequisite to paleoenvironmental proxy interpretation.
Highlights
Silty yellowish loess horizons with variable sand contents, partly accompanied by more brownish colors are repeatedly intercalated by pale horizons
Two weak brownish horizons divided by loess are present in the superimposed unit IX
To date there are no unified routines for loess colorimetry to provide robust color tuning as a tool to facilitate loess stratigraphy, but our results indicate a high potential for this approach
Summary
Meyer-Heintze et al.2011; Zech et al, 2013; Ha€ggi et al, 2014; Prud’homme et al, 2016; Moine et al, 2017). Few studies provide detailed stratigraphic information and evaluate the formation processes of LPS, which is prerequisite to interpreting their parameter variations (Antoine et al, 2013; Meszner et al, 2013; Sprafke, 2016; Meyer-Heintze et al, 2018). The tight chronology for the last glacial reference LPS Nussloch (Moine et al, 2017) demonstrates strong links between millennial climatic events and paleosol types/intensities in Central European LPS (Rousseau et al, 2017a). Interpretations of LPS can be complicated by reworking and erosion events (Lehmkuhl et al, 2016; Sprafke, 2016)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call