南海深海盆地沉积柱样中的浊流沉积

Fine-grained turbidite deposits from deep-sea basin in South China Sea

本文根据南海深海盆地三个沉积柱样的粒度结构、地球化学、微体古生物等特征分析,深讨了南海深海盆地细粒沉积物的浊积现象。结果表明,位于南海北部陆架斜坡上KL37孔的浊流沉积现象并不明显;位于陆架斜坡和深海盆地交界处的KL29孔存在着大量的浊积层,属于浊流沉积和半远洋沉积环境;位于南海盆地中部的KL91孔虽然已属于远洋性沉积环境,但除出现火山灰沉积外,浊流沉积作用仍然是相当活跃的。

Based on the grain-size texture, characteristics of geochemistry and microplaeontology of three cores in the South China Sea, the phenomena of fine grain turbidite in South China Sea are discussed. Turbidite deposits are not obvious in the Core KL37 situated in the northern slope of South China Sea continental shelf, however, study on Core KL29 situated in the juncture of the continental shelf slope and deep sea basin shows that the(hemi) pelagic and turbidite setting control the sedimentary process in this area,and that over half of sediments is deposited by turbidity currents, study on Core KL91 situated in the central area of the sea basin also shows that the sediments consisted of volcanic ash, pelagic setting and turbiditic setting make up over half of the sedimentary thickness.