OSL dating on the quartz of Late Quaternary sediments

Abstract

This paper introduces the optical luminescence dating method: SAR-OSL (Single Aliquot Regenerative Dose
Optically Stimulated Luminescence) of sand-sized quartz grains. This is the method used by the Geological Institute of
Hungary. It gives the age of burial of sediments (mainly sands, and silt or loess), and pays strict attention to their last
exposure to sunlight, up to about 100 ka.
OSL age-dating focuses on that luminescence which occurs during stimulation of the minerals by light when their
absorbed and stored energy from radioactive radiation is released. Therefore this method needs special sampling and
sample preparation to enclose light exposure. Based on the measurement of the natural luminescence signal of the quartz
grains, and then the response of these luminescence signals to different artificial radioactive doses given under laboratory
conditions, it is possible to calculate the dose (equivalent dose) which was absorbed by the sediment from the time of its
burial. The equivalent dose, divided by the dose which is absorbed by the covered sediment in a time unit (dose rate), gives
the OSL age. For luminescence measurement and irradiation the Geological Institute of Hungary uses a RISØ TL/OSL
DA-15C/D reader to determine the equivalent doses. Dose rate calculation, based on high resolution gammaspectrometry
measurements of sediments around the OSL samples, were carried out in the Eötvös Loránd eophysical Institute.