东太平洋深海沉积物元素地球化学特征及影响因素

Elementary Geochemical Characters of DeepSea Sediments and Influencing Factors in the East Pacific Ocean

本文对东太平洋ＣＣ区沉积物中的化学元素分析结果表示，该区为铝硅酸盐沉积，主要由ＳｉＯ２和Ａｌ２Ｏ３及其他金属氧化物组成，与陆源和火山源有关。东、西两区Ｍｎ的含量在柱状样和表层样中呈现相反的结果，表明了南极底层流对西区表层影响较大。两个岩芯沉积物多种元素含量的垂向变化的跃变，几乎同时发生在岩芯某一相同层位，这表明了在地质时期中曾发生过地质环境明显的变化，可能是地层界线的重要标志。火山作用加大了轻重稀土的分异程度，也就是说对轻稀土影响较大。

lementary analysis of the sediments of the cc area in the east Pacific Ocean indicates that they are aluminosilicates, mainly composed of SiO2,Al2O3 and other metallic oxides, and are related to terrigenous and volcanic sources.The spatial distribution of the Mn in the surficial sediments of the western area was different from that of the eastern area, which indicated that the Antarctic bottom current had a great influence on the surface sediments of the western area.The abrupt change of the vertical variation of the multielement in the sediments of the two cores which occurred nearly at the same horizon showed that marked geological environment must have changed during the geological epoch, which might be an important mark of stratiigraphic boundary.The vertical variations of rare earth elements concentrations in the core increased with the depth and this change in the western area was lower than that in the east. However, the rate of LREE/HREE decreased with the increase in depth and this rate in the west area was higher than that in the east. Volcanic action had strengthened the partition between LREE/HREE, i.e.LREE had been much more affected.