A geochemical application of the ITRAX scanner to a sediment core containing eastern Mediterranean sapropel units

Abstract: The ITRAX micro-X-ray fluoresence (XRF) core scanner has been applied in a sediment geochemistry investigation. The core sections selected ontain examples of the organic-rich sedimentary units (sapropels) that form periodically in the eastern Mediter-ranean basin. Sapropels are visually obvious from their dark coloration, but the ITRAX X-radiograph also reveals physical property changes that result mainly from the high pore-water content of sapropels. A consideration of wavelength-dispersive XRF data from discrete samples of the most recent sapropel (S1) was made along with the set of elements reported by the ITRAX instrument's energy-dispersive XRF system over core sections containing S1. This allowed selection f a suite of eight inter-element ratios or element integrals through which characteristic features of sapropel development and geochemistry were revealed. While recognizing that the measured XRF element integrals from the ITRAX do not have an exact constant relationship with element concentration ver changing sediment types, this combination of ratios provides ignificant information for geochemical interpretation. These include evidence for: (i) the presence of high Corg contents in the visual sapropel from Ba/Ti and Br/C1 ratios; (ii) a thinning of the original sapropel thickness b