Origin and dispersal of recent clay minerals in the Yellow Sea

Abstract

The clay minerals in the <2 μm fraction of 52 sediment samples from the Yellow Sea continental shelf have been determined by X-ray diffraction analysis. The results define the CYSM (central Yellow Sea mud) and the SEYSM (southern Yellow Sea mud) on the basis of clay mineral concentration and are interpreted in order to decipher the origin and dispersal of the recent clay minerals in the Yellow Sea. The CYSM is dominated by illite (av. 66%), smectite (av. 13%), chlorite (av. 12%) and kaolinite (av. 10%), whereas SEYSM is recognized as bearing illite (av. 71%), chlorite (av. 16%) and kaolinite (av. 14%) with a trace of smectite. By considering the clay minerals supplied by rivers in China (the old and present-day Huanghe River) and Korea (the Keum and Yeongsan) to the Yellow Sea continental shelf and the spatial variation in the distribution of clay minerals in the Yellow Sea, this study indicates that the provenance of the CYSM may be closely related to the old and present-day Huanghe River system, whereas the clay minerals in the SEYSM seem to be largely associated with the Keum and Yeongsan Rivers. In addition, smectite may be suggested as an important clay mineral in differentiating between CYSM and SEYSM and understanding the sources of these two mud categories.