Optically stimulated luminescence ages for the Upper Palaeolithic site Krems-Wachtberg, Austria

The loess-paleosol profiles at Krems in central Europe (Lower Austria) are well known for the impressive output of Upper Palaeolithic remains as well as for their paleoclimate potential as terrestrial archives. Previous high-resolution sedimentological and environmental magnetic results documented a rather complex sedimentological setting at Krems-Wachtberg, an Early Gravettian site. The site has been previously dated by radiocarbon as well as luminescence methods. Here, optically stimulated luminescence dating (OSL) methods and sedimentological analyses are reported for new profiles previously not investigated. Continuous wave luminescence (CW-OSL) has been performed on 16 samples on fine (4-11 μm) and coarse (63-90 μm) quartz grains. Despite extensive sample preparation the quartz extracts proved to be highly contaminated with other minerals. The application of standard single aliquot regenerative (SAR) protocol intrinsic rigour tests (recycling, IR depletion and recuperation) resulted in almost half of the analysed aliquots being rejected. Albeit improving the precision of the equivalent doses, the application of these rejection criteria did not result in significantly different average values. Pulsed OSL (POSL) has been further employed in order to better separate quartz OSL signals, but resulted in no significant change in the determined equivalent doses. Obtaining a higher accuracy and precision for the chronology of the Krems-Wachtberg site using currently available luminescence dating methods remains a daunting task, despite the archaeological and paleoenvironmental significance of the site.