LGM erosion and subsequent rapid loess deposition in Trzebnica (SW Poland)

Abstract The 7.7-m loess–paleosol sequence in Trzebnica records a short (ca. 3 ka) but intense phase of loess accumulation that preceded the onset of the Weichselian Late Glacial (MIS 2). The stratigraphy contains a well-defined erosional unconformity, marking a hiatus prior to the deposition of the youngest loess unit (L1LL1). The Trzebnica loess contains numerous signals of slope redeposition, as evidenced by lithological indicators. In this paper, we present optically stimulated luminescence (OSL) and radiocarbon data for the Trzebnica site, as well as granulometric analyses and end-member modeling of grain-size data. Our findings refine the regional loess stratigraphy and challenge an earlier hypothesis regarding the age of the Trzebnica 2 archeological site, which pointed to its evolution beginning around MIS 11. Limitations of 14 C dating and its comparison to OSL dates are discussed.