南海东部柱样沉积物锶同位素变化特征及其地质意义

Sr同位素比值可提供有关物质来源的重要信息,南海东部海域的3个柱样沉积物采用二端元组分混合模型,得到南部陆坡区69柱中陆源物质质量分数为42．48％～92．95％,平均为78．33％;中部深海区149柱中陆源物质质量分数为74．29％～85．04％,平均为81．63％;南部深海区294柱中陆源物质质量分数为53．55％～76．74％,平均为67．01％,3个柱样中陆源组分质量分数变化表明南海东部海域沉积物中陆源物质由北至南逐渐减少,而幔源物质逐渐增多,结合沉积柱样的δ^13C、δ^18O同位素数据分析反映南海15万年来经历了2次较大规模的冰期和3次间冰期。

Characteristics and geological significance of 87Sr/86Sr ratio in core sediments from eastern South China Sea

The ~(87)Sr/~(86)Sr ratio and the concentration of Rb and Sr of <100 mesh noncarbonate fractions of sediments taken from cores of 69,149 and 294 vary systematically.The concentration of terrigenous and basaltic component were calculated by a two-component mixing model.69 core has terrigenous content between 42.48 % and 92.95 % while 149 core contains from 74.29 % to 85.04 %,and 294 core has between 53.55 % and 76.74 %.Layers of sediment were defined with the carbon-13 and oxygen-18 data of the carbonate fractions.Sediments record in core sediments the Quaternary history of South China Sea.There are three interglacials and two glacials from 150 000 a in eastern South China Sea.