First Results of Comparative Analysis of the Chemical Composition of Pleistocene Sediments in the Indian and Atlantic Oceans

The geochemical features of Pleistocene sediments in the Indian and Atlantic oceans have been compared. We used 20 000 determinations of elements for sediments from each ocean to calculate their mean chemical composition. On average, Atlantic sediments are generally more carbonaceous than Pleistocene sediments in the Indian Ocean (32.17 wt % CaCO₃ vs. 24.51 wt % CaCO₃). They are more enriched with Fe₂O₃, Na₂O, P₂O₅, and Zr. The Pleistocene of the Indian Ocean is enriched with K₂O, Co, and Ni. The mass accumulation rates of all chemical components for the main lithological types prevail in the Atlantic. We propose that these results are due to a higher ratio of the watershed area to the accumulation basin area and higher primary productivity in the Atlantic Ocean. The geochemical specificity of Pleistocene sediments in the Indian Ocean can be largely explained by the specific composition of clay minerals and a larger distribution area of pelagic clays.