论文部分内容阅读
南海北部ODP1146站第四纪粘土矿物学分析表明,伊利石、绿泥石和高岭石含量在冰期时增高,而蒙脱石含量在间冰期时增高.蒙脱石/(伊利石+绿泥石)比率和蒙脱石丰度变化可以作为东亚季风演化的矿物学标志.在万年时间尺度上,间冰期盛行的西南表层洋流将更多的蒙脱石由南部和东部向北搬运,表现为加强的夏季风;冰期盛行的逆时针表层洋流将大量伊利石和绿泥石由台湾以及流经吕宋海峡的长江物源搬运至南海北坡,表现为强盛的冬季风.就10万年时间尺度而言,蒙脱石/(伊利石+绿泥石)比率与沉积速率的对应关系,指示2000～1200和400-0 ka期间南海北部盛行冬季风,而1200-400ka期间表现为加强的夏季风.夏季风演化的强弱与北半球夏季目射量基本呈线性关系,表明东亚季风演化的天文驱动机制.
Quaternary clay mineralogical analysis of ODP1146 station in the northern South China Sea shows that the contents of illite, chlorite and kaolinite increase during the glacial period, while the montmorillonite content increases during the interglacial period.Montmorillonite / (illite + chlorite ) Ratio and montmorillonite abundance can be used as a mineralogical indicator of the evolution of the East Asian monsoon.On thousands of year time scales, more montmorillonite transported in the southwestern surface currents prevailing in the interglacials migrated from the south and the east to the north, Intensified summer monsoon; counter-clockwise surface currents in the ice age carried a large amount of illite and chlorite from Taiwan and the Yangtze River source flowing through the Luzon Strait to the northern slope of the South China Sea, showing a strong winter monsoon. On the 100,000-year time scale , The correspondence between the ratio of montmorillonite / (illite + chlorite) and sedimentation rate indicates that the winter monsoon prevailed in the northern South China Sea during 2000 ~ 1200 and 400 ~ ka, while the intensified summer monsoon over 1200-400 ka The strong correlation between the summer monsoon and the northern hemisphere summer has basically linear relationship, indicating the astronomical driving mechanism of the evolution of the East Asian monsoon.