南海中北部海域晚更新世以来沉积速率及其变化机制

Sedimentary rates and changing mechanism in northern and middle South China Sea since Late Pleistocene

本文根据沉积速率变化受沉积环境制约机理，计算了南海中北部海域晚更新世以来沉积速率的变化，分析该海域沉积环境的特征。通过7个柱状样沉积造车的计算与分析，认为晚更新世以来沉积达率明显高于典型的大洋沉积环境的沉积速率，平均为10．2cm／ka，北部海域平均沉积速率为11．3cm／ka，南部海域平均沉积达率为6．0cm／ka，表现为近陆区沉积速率高，远离大陆速率低的特点。另外，晚更新世沉积速率为28．9cm／ka，高于全新世沉积速率（9．3cm／ka）。这三个特点大反映南海中北部海域的沉积环境属于近海──深海的边缘海环境。

Based on the rnechanism that the sedimentary rates are controlled by the sedimentary ,this calculates the changes of the sedimentary rates and analyzes the characteristics of the sedimenlary environments in the southern and northern parts of the South China Sea since the Late Pleislocene. It is shown that the sedimentary rate in the study area (10. 2cm/ka in average ), according to the calculation and analysis of that in seven cores, is distinctly higher than that in the typical oceanic environments. The average sedimentary rate of 11. 3cm/ka in the northern and 6. 0cm/ka in the southern Parts of the study area indicates a seaward de creasing sedimentary rate. These two fcatures, together with higher sedimentary rate in the Late Pleistocene (28. 9cm/ka ) than that in the Holocene (9. 3cm/ka ) indicates a shallow-deepnlarginal sea enviTonment in the northern and middle South China Sea.