Optically stimulated luminescence (OSL) dating investigations of rock and underlying soil from three case studies

Abstract

Three rock samples and associated underlying surface (floor) soils of geoarchaeological significance from Greece, Sweden and a modern surface stone-sample from a Danish site were investigated using OSL dating. Thin slice, sub-samples, from drilled core surfaces were prepared. A single-aliquot regenerative-dose (SAR) protocol was used on whole rock slices to estimate the laboratory equivalent dose. Laboratory tests showed that the SAR protocol successfully corrected for sensitivity changes and that a known laboratory dose could be measured accurately. The luminescence signals from quartz and feldspar stimulated by blue light and from feldspar under IR stimulation were employed in equivalent dose calculations. Only IR signals showed measurable fading on a laboratory timescale. Laboratory tests showed that daylight bleaching of the rock surfaces is rapid, and that the light-exposed region extended into the solid rock. The geoarchaeological ages obtained for the rocks and soils were in satisfactory agreement with independent age estimates.