Our oldest children: Age constraints for the Krems-Wachtberg site obtained from various thermoluminescence dating approaches

We present several approaches to directly date the prehistoric human activity of lighting a fire at the Early Gravettian infant burial site of Krems-Wachtberg (Austria) by thermoluminescence (TL) methods. Blue thermoluminescence (B-TL) from polymineral fine grain and orange-red thermoluminescence (R-TL) from fine-grained quartz separates, both extracted from the baked loess immediately underlying the hearth were employed. The B-TL dating followed the “classic” multiple aliquot-additive dose (MAAD) protocol. For R-TL dating, the multiple aliquot-regenerative (MAR) and a shortened single-aliquot-regeneration (SAR) protocol were tested. All thermoluminescence ages obtained agree within 1-σ uncertainties and assign a weighted mean age of 33.9 ± 2.3 ka to the last use of the hearth and by inference to the infant burial. Anomalous fading is precluded due to the agreement of results from all luminescence protocols as well as with independent dating methods. The TL ages are consistent with calibrated radiocarbon ages on associated charcoal, OSL dating of the sediment deposition and with age estimates obtained by two magnetic dating approaches.