【作者】 李学杰； 汪品先； 徐彩珍； 徐元爱；

【Author】 Li Xuejie Wang Pinxian Xu Caizhen Xu Yuanai Guangzhou Marine Geological Survey, Guangzhou 510760 State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092

【机构】 广州海洋地质调查局； 同济大学海洋地质国家重点实验室；

【摘要】 对南海西部进行表层沉积物进行系统取样分析表明,该区粘土矿物总体以伊利石为主, 平均含量超过50％,其次为蒙脱石,绿泥石和高岭石含量较低。伊利石和蒙脱石含量变化较大,两者呈负相关关系,而绿泥石和高岭石含量变化较小,两者呈正相关关系。根据粘土矿物组合及其分布特征,南海西部海域大致可以分为A、B、C、D、E五区, 其中A区以高伊利石和低蒙脱石含量为特征,B区伊利石含量明显下降,蒙脱石含量增多, C区以较高蒙脱石含量和低绿泥石、高岭石含量为特征,D区和E区,总体为低伊利石,高蒙脱石、绿泥石和高岭石,其中E区蒙脱石含量最高。与邻区粘土矿物组合对比研究表明,高伊利石含量的A区物源可能主要来自东北方向, 台湾海峡,包括台湾岛,甚至长江是其主要来源。越南岸外的陆坡区细粒沉积物与陆架区有明显的继承性,表明其物源主要来自中南半岛,而红河物源对陆坡及深海盆的影响相对较小。南部陆架-陆坡区的物源主要有湄公河和加里曼丹岛,但两者的混合明显。因此从区域分布来看,来自台湾海峡的细粒沉积物对南海深海盆影响可能最大,这可能主要是有由于表层环流所致。更多还原

【Abstract】 257 surface sediment samples were collected from the western South China Sea (SCS), covering the shelf, slope to the deep sea basin. They were analyzed for clay minerals. The result is predominant by illite, with average content of >50% in the all area, secondly is smetite and slight lower content of chlorite and kaolinite. The contents of illite and smetite change much larger than that of chlorite and kaolinite. The changes of illite content play a distinctly positive relationship with that of smetite, while changes of chlorite content are negative relationship with that of kaolinite. Based on the assemblages of clay minerals and their distribution, 5 provinces of A, B, C, D, E were classified in the research area. It is characteristic with very high content of illite and low content of smetite in Province A; the content of illite in Province is lower than Province A but content of smectite is higher. Relative higher content of smetite and lower content in Province C, while lower content of illite and higher content of smetite, chlorite and kaolinite in Province D and E as totally. By compared with adjacent areas, the assemblage of clay minerals in Province A is more similar to that in Taiwan Strait and Yangtse River and in the Estuary of the Peral River and Hanjiang River. It is suggested that the provenance of Taiwan Strait should be more important than that of the two rivers. The provenance of the Province C should be mainly from the Indo-China Peninshular, as the similar the assemblage of clay minerals similar with that in the Vietnam Shelf. The provenance of Southern shelf and slope should include the Mekong River and Kalimantan Islands. Therefore the provenance of clay from Taiwan Strait should be the most important for the Xisha Trough and its southeastern deep sea basin, while the provenance from the Red River should be in the shelf mainly.更多还原