3.7 Ma以来西菲律宾海XT-4孔沉积物元素特征及其古环境指示意义

对西菲律宾海盆南部XT-4孔柱状沉积物进行了元素地球化学分析，利用常量元素上地壳标准化图解和R型因子分析方法进行了物源探究，利用因子分析得出的陆源因子得分变化探讨了物源区的古环境演化。结果表明：XT-4常微量元素垂向上变化主要受控于亚洲内陆的风尘物质和周边火山物质的输入，海洋自生物质也有一定的贡献。以TiO₂和K₂O等元素为代表的陆源因子得分自3.7 Ma BP以来表现出阶段性上升的变化趋势，与中国黄土和北太平洋ODP 885/886站沉积物记录的东亚冬季风演化记录有着良好的对比性，同时与青藏高原主要的阶段性隆升时间相对应，响应了晚新生代以来青藏高原隆升对东亚冬季风加强的作用。本研究丰富了西菲律宾海盆的风尘沉积研究，为后续研究提供一定的认识基础。

Elemental geochemistry of Core XT-4 sediments from the western Philippines Sea since 3.7 Ma and its paleoenviron-mental implications

Elemental geochemical analysis was performed on core XT-4 sediments in the southern part of the Western Philippines basin; with the help of standardized crustal normalization diagrams and R-type factor analysis methods, the provenance of the source was investigated; and by factor analysis, the change of the terrestrial factor scores obtained and the evolution of the paleoenvironment in the provenance area are discussed. The results show that the vertical change of XT-4 normal trace elements is mainly controlled by the input of wind and dust materials and surrounding volcanic materials in Asia, and in addition, the marine biomass also contributes to this change. The terrestrial factor scores represented by elements such as TiO₂ and K₂O have shown a gradual upward trend since 3.7 Ma Bp, and have formed a obvious contrast with the evolution of the East Asian winter monsoon recorded in the sediments of the Loess and North Pacific ODP 885/886 stations. In addition, these trends correspond to the major periodic uplift times of the Qinghai-Tibet Plateau, and respond to the strengthening of the East Asian winter monsoon since the late Cenozoic.