Photon-stimulated luminescence of quartz from loess and effects of sensitivity change on palaeodose determination

In an attempt to improve the accuracy and precision of optical dating for l oess deposits, we have measured photon-stimulated luminescence (PSL) or opt ically stimulated luminescence (OSL) of fine-grain quartz extracted from lo ess using blue-green light stimulation. The luminescence signal of quartz i s shown to have three components which decay with markedly different rates upon stimulation The preheat procedures employed during the measurements ga ve rise to changes in luminescence sensitivity. The sensitivity changes mon itored by the 110 degreesC TL peak and OSL responses to a test dose are sho wn to be dependent on factors such as preheat temperature, number of cycles and radiation doses. The preheat-induced sensitivity changes occur in both single- and multiple-aliquot based methods. We show that with an OSL sensi tivity correction in the single-aliquot regeneration method, high-precision palaeodose values with uncertainty smaller than 5% can be obtained for fin e-grain quartz from loess. (C) 2000 Elsevier Science Ltd. All rights reserv ed.