关键词: 晚更新世, 沉积物, 常量元素, 地质意义, 东海陆架

Abstract:

Based upon analysis of lithology，grain-size，major elements and dating data for core SFK-1，which is located in the depression area of Xihu on the continental shelf of East China Sea，this contribution studied the geochemical characteristics of sediments since the Last Pleistocene. The results showed that geochemical information of elements has good indicator significances to stratigraphical division．The mean of each major element was respectively SiO₂ 65.35%，Al₂O₃ 12.12%，FeO 1.75%，CaO 3.88%，MgO 2.04%， K₂O 2.63%，Na₂O 2.04%，TiO₂ 0.66%，P₂O₅ 0.12%，MnO 0.065%，TFe₂O₃ 4.74%，CaCO₃ 5.38%，with less coefficient of variation，indicated a smaller divergent extent of major element. The variations of CaCO₃/TiO₂, CaO/TiO₂ and P₂O₅/TiO₂ ratios can reflect the intensity of weathering；The TiO₂/Al₂O₃ ratio can be used as a paleo-stream energy indicator to reflect the intensity of stream hydrodynamic conditions；The variations of SiO₂/TiO₂, Na₂O/TiO₂ ratios can be used as proxies to reconstruct the sedimentary hydrodynamic conditions for the whole core sediment. The divisions of the 8 layers are respectively connected with the grain size of sediment，climate change boundary, strata boundaries according to the vertical variation characteristics of major elements，which reflect the change of sediment environment in East China Sea since the late last interglacial cycle ( warm period).

Key words: Late Pleistocene, sediments, major elements, geological significance, continental shelf of the East China Sea