The Late Pleistocene loess deposits and palaeosols of eastern Belgium: new TL age determinations

Abstract

Fourteen samples from the Pleistocene loess exposures at Kesselt (Belgian Limbourg) have been dated with the thermoluminescence method. Using the regeneration technique and a double analysis with two types of blue transmittant filters, reproducible age estimates were obtained up to about 130–140 ka. For the basal part of the late Weichselian (Brabant) loess and the underlying cryorurbated Nagelbeek Horizon we arrived at ages of 20–22 ka, which is consistent with the radiocarbon age of this horizon (22.3 ka). Our TL dates further constrain the formation of a lower luvisol profile, the Bt horizon of which has been correlated with the Rocourt palaeosol, to the period 50–60 ka. These dates, however, may overstimate the true age of the sediment because they were obtained on reworked loess. They indicate that this palaeosol was formed during a Middle Weichselian interstadial and not during the Eemian as is generally accepted. The boundary between the Weichselian and the older loess is situated at a lower level in the Kesselt profile. The loess bracketing the deeper tundra gleysols yielded TL ages up to 130–140 ka and the ages further rapidly increased with depth, indicating that the sediments may even be much older than Saalian. © 1998 John Wiley & Sons, Ltd.