Carbonate mineralogy and faunal relationship in tropical shallow water marine sediments: Cape Comorin, India

Abstract

The carbonate mineralogy of Recent sediments from the western and eastern continental shelves around Cape Comorin off the southern tip of India was determined by X-ray diffraction analyses. The results show that in the sediments where benthic foraminifera are the most abundant component, as on the extreme western side and on a narrow strip between the depths of 40 and 50 m, on the eastern side (Gulf of Mannar), the carbonate mineralogy is dominated by high magnesium calcite. In sediments where molluscs exceed other components, as on the eastern shelf between 10 and 40 m, the most abundant mineral is aragonite. Low-magnesium calcite does not appear to be related to depth or carbonate components