Characterization of luminescence properties of insoluble mineral grains extracted from the Greenland Summit GRIP ice core, and their potential for luminescence dating

We describe several optically stimulated luminescence (OSL) and thermoluminescence (TL) properties of insoluble mineral grains extracted from the Greenland summit GRIP ice core in order to examine the potential of these techniques for age determination of these materials. Since the dust grains examined in this work were exposed to natural and artificial light at many stages prior to luminescence analysis, the purpose of the experiments reported herein was not to make age determinations, but rather to evaluate the general suitability of dust grains extracted from ice cores for luminescence dating. The measurements indicate that the fine-grained dust has a wide dynamic dose response range, with limited saturation effects being seen until absorbed doses of ∼1000Gy. Furthermore, the sample's TL and OSL signals were stable over the time intervals evaluated in this study and readily susceptible to bleaching by exposure to sunlight. These three properties form a stable base for the development of luminescence dating procedures for insoluble mineral grains recovered from ice cores. The experiments demonstrate that such procedures can be carried out on sample masses of less than 1mg.