Provenance Study of Holocene Sediments in Subei Coastal Plain ——Comparison between elemental geochemistry and heavy mineral methods

Key words: 
• provenance /
• Subei coastal plain /
• Holocene /
• elemental geochemistry /
• heavy mineral

Abstract: Element geochemical and heavy mineral methods are applied to study provenance of Holocene sediments in Subei coastal plain. Based on core analyses, that sedimentary strata developed in Subei coastal plain during Holocene mainly include littoral facies, offshore-neritic facies and tidal flat facies from the lower part to the upper part. The authors firstly resarched elemental and heavy mineral compositions of the Changjaing and the Huanghe sediemnts, and study shows there are obvious differences between both sediments. Some elements and heavy minerals can be applied to trace the Changjiang and the Huanghe sediments and study the diffusions and mixture of both rivers in coastal zones. And then, elemental and detrital mineral compositions of Holocene sediments from four drilling cores in Subei coastal plain are determined in detail. Analyses reveal that the Huanghe River is the dominant provenance and supplied more matters for formation of Holocene sediments than the Changjiang River. During early Holocene, influence of the Changjiang matter exceeded that of the Huanghe matter. After the maximal transgression in Holocene, the Huanghe River arrived the South Yellow Sea and carried abundant sediment, and the Changjiang River supplied limited matter by a narrow distributary and its influence was small. During the last two thousand years, sediments of this area were mainly from the Huanghe River. Study also shows that elemental geochemical method is more useful than heavy mineral method in provenance discrimination because the former can effectively avoid the influence of hydraulic sorting.