SEDIMENT PROVENANCE AND FLUXES IN THE NORTHERN OKINAWA TROUGH DURING THE LAST 88 KA

The history of terrigenous detritus accumulation and paleoenvironment since the last 88 ka was reconstructed using the results of rare earth elements (REEs) from 131 samples from the Northern Okinawa Trough. The results show that the contents of ∑REEs vary between 111~171.3 μg/g with an average value of 130.9 μg/g. The apex of ∑REEs occurs in MIS 2, while the low values exist in Holocene. Negative Cerium anomaly exists in MIS 4, which is mainly controlled by the ventilation of deep water. Provenance analysis suggests that the sediment components are dominated by terrigenous detritus during MIS 2 and MIS 5a, while the contribution of volcanic detritus significantly increases over the last 8 ka. There exists provenance difference between MIS 2-MIS4, and the early and late last deglacial periods. Both sea level and East Asian Summer Monsoon are the main controlling factors for terrigenous detritus accumulation in the northern Okinawa Trough.