PROVENANCE OF SURFICIAL SEDIMENTS OF THE EAST PHILIPPINE SEA: EVIDENCE FROM RARE EARTH ELEMENTS

To further understand the provenance of the surficial sediments in the East Philippine Sea, 30 samples have been analyzed for rare earth elements (REE) compositions and clay mineral assemblages. Based on the REE data and a simplified two end-member mixing model, we quantitatively calculated the contributions of the eolian dust and the local volcanic debris to the study area. It shows that the contribution of the eolian dust to the study area is decreasing with the distance from the source area of the dust (i.e., the Asian continent), while the contribution of the local volcanic matter shows a converse trend, with high values near the Parece Vela Trench. The results are very consistent with the conclusion from clay mineral assemblages and ⁸⁷Sr/⁸⁶Sr data of the studied samples and the conclusions from the two end-member mixing equation provided by published literatures. It suggests that the simplified calculation model is valid for provenance study in this region.