南黄海表层沉积物碎屑石榴石化学组成及物源示踪应用

Detrital Garnet Compositions of the Surface Sediments in the South Yellow Sea and Their Tracing Implications

通过对南黄海表层沉积物样品的单颗粒碎屑石榴石进行电子探针测试,确定其化学组成特征及2种主要的石榴石组合,即分布在中北部的低Mg高Mn的中低级变质岩和接触变质岩组合、中南部高Mg低Ca的中—高级变质岩组合,根据石榴石在物源端元三角形图解中的分布,探讨其物源组成,将研究区划分出3个物源相应区,分别是长江物源相应区、黄河物源相应区和二者之间的混合过渡区域。此外,近岸的山东半岛等近源物质对南黄海表层沉积物的石榴石组成也有影响。

By the microprobe analysis of the detrital garnets of the surface sediments in the South Yellow Sea,their composition characteristics and assemblages have been identified.According to garnet compositions distributions in the triangle and the sample locations,their internal relations can be inferred.Those samples in the north area poor in Mg,rich in Mn related to the medium low grade metamorphite and contact metamorphic rock are from Changjiang River,however,those rich in Mg,poor in Ca related to medium-to high-grade metamorphic rocks are from Huanghe River.And there is a source-mixing band area between the two main provenance corresponding areas.Additionally,the garnets carried by the coastal current from the granite of the Shandong Peninsula also affect the distribution.