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赤道西太平洋作为全球变化关键海区,其沉积物组成对揭示古海洋、古环境变化具有重要意义.本文利用元素地球化学分析方法,对赤道西太平洋翁通爪哇海台WP7站位(3°56′S,156°00′E)柱状沉积物进行了研究.结果显示元素Al、Na、K、Be、Ga、Rb、Zr、Nb、Cs、Ce、Hf、Ta、Th、Fe和Mg经Ti标准化后,无法用单独的碎屑物质来源解释,而是分别同偏酸性和偏基性火山灰相关,指示了249.5ka以来,共发生了4次偏酸性火山灰输入(2.5～6.4ka、57.0～61.2ka、79.7～88.4ka和193.7～249.5ka)和4次偏基性火山灰输入(19.8～24.4ka、50.0～62.6ka、143.2～150.5ka和160.8～171.1ka).火山灰的输入使沉积物元素地球化学组成发生了相应变化,也使沉积物中碳酸钙产生了稀释效应,从而沉积物颜色相应加深,沉积速率显著提高.
As the key sea area of global change, the equatorial Pacific Ocean is of great importance in revealing paleoceanographic and paleoenvironmental changes.In this paper, elemental geochemical analysis is used to analyze the distribution of sediments in the WP7 station (3 ° 56 ’ S, 156 ° 00’E) columnar deposit.The results show that the elements Al, Na, K, Be, Ga, Rb, Zr, Nb, Cs, Ce, Hf, Ta, Th, Fe and Mg are normalized by Ti , It can not be explained by a separate source of clastic material, but separately related to the partial acidity and the partiality pozzolana, indicating that a total of four acidic volcanic ash inputs (2.5-6.4 ka, 57.0-61.2 ka) have occurred since 249.5 ka , 79.7 ~ 88.4 ka and 193.7 ~ 249.5 ka) and 4 times of partial volcanic ash input (19.8 ~ 24.4 ka, 50.0 ~ 62.6 ka, 143.2 ~ 150.5 ka and 160.8 ~ 171.1 ka). The input of volcanic ash made the sediment element geochemistry The composition of the corresponding changes have also made the sediment calcium carbonate dilution effect, so that the corresponding darker sediment, the deposition rate was significantly increased.