Abstracts Earth and Environmental Sciences

Mineralogic controls on the infrared stimulated luminescence of feldspars: an exploratory study of the effects of Al,Si order and composition on the behavior of a modified post-IR IRSL signal

by JILLIAN Daniels

The luminescence characteristics of a variety of feldspars were investigated using the post-IR IRSL signal to facilitate the understanding of the origins and behavior of signals used in luminescence dating. These feldspars were characterized in terms of major composition, Al,Si ordering, and minor impurities, and compared to the luminescence decay parameters of brightness, bleachability, and kinetic order calculated from the pIRIR decay signal. The behavior of these parameters over varying preheat temperatures, pIRIR measurement temperatures, IR50 measurement times, and first IR measurement temperatures were analyzed. Correlations between the physical and the luminescence characteristics were noted, as well as the general behavior of similar feldspar samples over different dating protocol parameters. Variations in Al,Si order were found to have the largest effect on K-feldspars, although some luminescence parameters were surprisingly insensitive. It may be that <T-O> bond length has a fundamental effect on the luminescence origin of all feldspar species.