东经90°海岭远洋沉积物非碳酸盐组分的粒度特征及环境指示意义

The Characteristics of the Non-CaCO_3 Grain Size of Pelagic Sediment from the Ninetyeast Ridge and Its Indicated Significance of Environment

对东经90°海岭北部ODP758站位远洋沉积物进行了粒度分析，得到了3．6Ma以来非碳酸盐组分的粒度变化曲线，得出在3．6～2．8Ma之间，非碳酸盐组分的粒度以2bLm为主；2．8Ma至今，粒度增大至3μm左右，并且比较稳定地保持增大趋势的结论，这与南亚冬季风的爆发和加强密切相关。印证了青藏高原的隆升对亚州季风的影响。

The sediments of ODP758 in the north of the Ninetyeast Ridge were analysed by grain. By the curve of non-CaCOa grain size in Site 758 during past 3.5 Ma ,some significant signals of the non-CaCO3 grain size tell us the variable ocean environment. The granularity gives priority to 2μm from 3.6 Ma to 2.8 Ma, and gives priority to 3 μm from 2.8 Ma to present, also holding the enlarged trend. These data show their response to the enhanced Asiasouth winter monsoon and it is correlation with uplift of the Tibet plateau.