East Pacific Rise 13 ¡ã N. Sediment Elemental Geochemistry

Element analyses have been carried on the sediment cores from East Pacific Rise 13°N. Sediments are enrichment in Fe and Mn. Core E271 Fe contents from 8.5% to 13.8% and 5.7% to 13% in E272, Mn contents from 1.7 to 3.17% and 6 to 13% respectively, which indicate important sedimentation influence of hydrothermal plume at a distance of 25 to 45km west from EPR 13°N hydrothermal field. Carbonates also occupy an important component, E271 from 5.9% to 27.6% and E272 from 6.7% to 38.2%. A few foraminifer fossils were found in the sediment cores. The sediments enrich Cu, Pb and Zn which are fallout from hydrothermal plume with iron oxides. Cu/Fe, Pb/Fe and Zn/Fe ratio are lower than those in vent particles, besides Pb performs short transport distance or only few Pb transported with iron oxides particles. Sediments also enrich in Li, Mo and Ni as well. Further, plume supplies V to underlying sediment by scavenge from seawater. Ti and Al have a good correlation, Ti/Al ratio nearly at 0.05. A similar contains between sediments and pelagic for U.