Quantification of aeolian dust (Kosa) contribution to the Japan Sea sediments and its variation during the last 200 ky

In order to reconstruct past variations in the aeolian dust (Kosa) contribu tion to the japan Sea, and to establish a direct link between terrestrial a nd marine climatic records, we have applied statistical procedures to disti nguish and quantify detrital subcomponents within the detrital fraction of the late Quaternary hemipelagic sediments in the Japan Sea. Q-mode factor a nalysis with varimax and oblique rotation of the factors followed by multip le-regression analysis between mineral composition and factor loadings was conducted using six "detrital" elements. Four detrital subcomponents were d efined, which are attributed to Kosa derived from "typical" loess, Kosa fro m "weathered" loess, and fine and coarse are-derived detritus, respectively , based on comparisons with the chemical and mineral compositions of probab le source materials. Using these detrital subcomponents, the variation in K osa fraction was reconstructed for the last 200 ky. The results reveal mill ennial-scale as well as glacial-interglacial scale variations in Kosa contr ibution. Especially, millennial-scale variability of Kosa contribution sugg ests the presence of high frequency variation in summer monsoon precipitati on in the central to east Asia during the last 200 ky.