Late Quaternary pelagic aragonite preservation in the Arabian Sea and its paleoceanographic implications

Abstract

In the course of the Quaternary the carbon dioxide concentrations of the atmosphere showed large fluctuations related to the oceanic carbon cycle and carbonate system. The production, accumulation, and dissolution of pelagic aragonite constitutes a considerable part of the oceanic carbonate system. Variations in water mass properties, atmospheric and oceanic circulation, which lead to changes in bioproductivity in the upwelling areas influence the preservation of aragonite and therefore the preservation of pteropod shells. This project is concerned with Late Quaternary preservation of pteropods in sediments of the Arabian Sea. To this purpose 15 surface sediment samples and two high resolution sediment cores from the Arabian Sea have been analysed by means of the pteropod shell preservation index LDX (Limacina inflata dissolution index, Gerhard and Henrich, 2001) in respect to the aragonite preservation state. One objective was to test and apply the newly developed LDX on sediments from the Arabian Sea and to trace spatial and temporal variations in pteropod preservation.