A SCANNING SYSTEM FOR MEASURING THE AGE-RELATED LUMINESCENCE OF SPLITSEDIMENT CORES

This article describes the development and performance of an integrate d optical sensor system that has been designed for rapid analysis of s plit sediment cores. The primary aim of the system is to obtain inform ation based on optically stimulated luminescence (OSL) techniques; the se provide a record of the accrued radiation dose of material since de position. Particularly after suitable normalization, the luminescence signal recorded along the length of the core will provide information on the relative age of the sediment. Two wavelengths of stimulation ar e used (infra-red and green) and these probe the feldspar, and combine d feldspar and quartz components of the sediment respectively; the rat io of the two signals can thus provide some indication of relative cha nges in the silicate mineralogy. A secondary use of the system is for optical reflectance measurements. With the addition of a monochromator , optical reflectance spectroscopy can be applied to obtain additional information on down-core mineralogical changes. In this article we de scribe technical aspects of the sensor system, discuss measurement tec hniques and consider the relevance of data obtained. Two examples of s ediment cores are presented, which demonstrate the applicability of th e instrument.