THERMOLUMINESCENCE PROPERTIES OF FINE-GRAIN MINERALS IN LOESS

Abstract

The age of deposition of an aeolian deposit such as loess may be found using thermoluminescence (TL) measurements to obtain the radiation dose that the deposit has received since that time. The radiation dose received by unseparated 4− to 11-micrometer grains extracted from a late Devensian loess is found to be the same as that received by 4− to 11-±m quartz grains extracted from the same sample. This confirms that the polymineral TL, which is dominated by the feldspar TL, is not subject to anomalous fading. The quartz response is linear up to about 20 kilorads, which allows the dating of samples younger than about 30 kiloyears. However, for larger doses the response appears to saturate, which precludes the use of fine-grain quartz for dating older samples.