The First Results of Comparative Analysis of Chemical Composition of Pleistocene Sediments from the Pacific and the Atlantic Oceans

The geochemical peculiarities of Pleistocene sediments from the Pacific and the Atlantic oceans have been compared. We used almost 20 000 determinations of elements for the Atlantic Ocean sediments and more than 47 000 determinations for the Pacific Ocean sediments to calculate their mean chemical composition. Pacific hemipelagic clays and volcanic sediments are rather similar in chemical composition and differ from those of the Atlantic Ocean. It has been revealed that Atlantic sediments are, on average, more calcareous than Pleistocene sediments of the Pacific Ocean (32.09 wt % of СаСО3 vs 18.18 wt % of СаСО3, respectively). They are enriched with MgO and P2O5 and the loss on ignition (LOI) in them is higher. Pleistocene deposits of the Pacific Ocean are enriched with oxides of other major elements (SiO2, TiO2, Al2O3, Fe2O3, MnO, Na2O, and K2O). Mass accumulation rates of all chemical components for main lithological types (except for hemipelagic clays) dominate in the Atlantic. We propose that these results are related to higher ratio of the watershed area to the accumulation basin area in the Atlantic Ocean.