Discrimination of geochemical compositions between the Changjiang and the Huanghe sediments and its application for the identification of sediment source in the Jiangsu coastal plain, China

Abstract

Concentrations of 25 elements in the fine-grained fraction (< 63 mum) of bottom sediments of the Changjiang and the Huanghe were determined to characterize the geochemical compositions of each riverine origin. Most of the elements, except for alkali and alkaline earth elements (Na, Ca, Sr and Ba), are highly enriched in the Changjiang sediments compared to those in the Huanghe sediments. Differences in source rocks and weathering mechanisms between the two drainage basins are the major factors controlling those compositional characteristics. The provenance index of core sediments from the northern Jiangsu coastal plain, calculated with nine elements with distinct compositional differences between both river sediments, indicates that the Changjiang had prevailed in the coastal plain sedimentation during the early stage of Holocene, while the Huanghe dominated over the area during the late Holocene. However, neither of the signatures of the modern Changjiang- and Huanghe-derived sediments is remarkable in the present-day coastal plain. (C) 2002 Elsevier Science B.V. All rights reserved.