RARE EARTH ELEMENTS IN SEDIMENTS OF WEST PHILIPPINE SEA AND THEIR IMPLICATIONS FOR SEDIMENT PROVENANCE

The composition of rare earth elements (REE) in sediments, which are effective in revealing the geochemical characters and sources of sediments, is used as a clue to understand the complex geological processes of the West Philippine Sea from the east Luzon Island to the Kyushu-Palau Ridge. Major and minor elements are analyzed. By comparing the concentrations of major and rare earth elements in addition to the REE distribution patterns in different parts of the studying area, we found that REE mainly occur with clay minerals, authigenic Fe-Mn oxide particles and apatite. The sediments in the basin between the Luzon Island and the Benham rise may contain some materials derived from ophiolites from the east of Luzon Island. The sediments in the basin to the west of the central rift and the area covered by nodules containing clays are comprised of the eolian dust from the continent,submarine volcanoes and authigenic materials.