Element geochemistry of Holocene sediment and paleoenvironmental change in the Changjiang Estuary

摘要

Analyses of 41 elements reveal that Holocene sediments in the Changjiang Estuary bear regular elemental compositions in different sedimentary environments, and Holocene sedi- mentscame mainly from the Changjiang River based on compositions of REEs and most trace elements. Some heavy metals are more enriched in the surface sediment than in the deltaic sedi- ments, reflecting human impact. Elemental compositions of the river channel sediment are related to the influence of proximal sediments. Sedimentary environments exert some influences on ele- mental compositions. Some chemical indices can be used to record chemical weathering under- gone by the Changjiang sediment and environmental change.