A high resolution optical dating study of the mostistea loess-palaeosol sequence (Se Romania) using sand-sized quartz

Abstract

We report on SAR-OSL dating of closely-spaced samples from the loess-palaeosol sequence near Mostistea lake (Danube Plain, SE Romania). We used sand-sized quartz and a SAR protocol that involved a preheat of 10s at 220°C and a test dose cutheat to 180°C. It is shown that these thermal pretreatments isolate a quartz OSL signal that is dominated by the fast component. The behaviour of this signal in the SAR protocol is then documented. The ratio of the measured to given dose tends to lie slightly but systematically above unity (~5% on average) and the recycling ratio below unity (~6% on average); for all samples, the recuperated signal is negligible. Within analytical uncertainty, the nineteen optical ages are internally consistent and agree with the predictions from a palaeomagnetic age-depth model. Although it may be possible to optimize the SAR measurement procedure, the optical ages already confirm the chronostratigraphic position of the uppermost welldeveloped palaeosol in that it formed during MIS 5.The established chronology allows correlating the sequence near Mostistea lake with that near Mircea Voda that we investigated earlier. © 2011 Silesian University of Technology.