Metal accumulation rates in sediments from the Southwestern Pacific Basin

Element accumulation rates for 19 elements in 11 sediment cores from the So uthwestern Pacific Basin have been computed. Fe, Mn, V, Co, Ni, Cu, Zn and Ph show highest accumulation rates in sediments taken in the vicinity of th e East Pacific Rise. These rates reflect a hydrothermal component in the se diments but are not as high as previously reported for other oceanic spread ing centres. As expected, the deposition rate of the hydrothermal component shows a steep fall-off with distance from the crest of the East Pacific Ri se. Accumulation rates for the authigenic elements are generally within the range found by other authors. Ignoring the sediments in the vicinity elf t he East Pacific Rise, the detrital component is seen to be the dominant com ponent in the red clays form the Southwestern Pacific Basin. On average, th ese clays consist of the following components (on a carbonate-free basis): detrital (92.0%), hydrothermal (0.0%), biogenic (4.9%), hydrogenous (1.6%) and residue (1.5%).