ABSTRACT

Element accumulation rates for 19 elements in 11 sediment cores from the Southwestern Pacific Basin have been computed. Fe, Mn, V, Co, Ni, Cu, Zn and Pb show highest accumulation rates in sediments taken in the vicinity of the East Pacific Rise. These rates reflect a hydrothermal component in the sediments but are not as high as previously reported for other oceanic spreading centres. As expected, the deposition rate of the hydrothermal component shows a steep fall-off with distance from the crest of the East Pacific Rise. Accumulation rates for the authigenic elements are generally within the range found by other authors. Ignoring the sediments in the vicinity of the East Pacific Rise, the detrital component is seen to be the dominant component in the red clays form the Southwestern Pacific Basin. On average, these 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%).