中国多金属结核开辟区沉积物中微量元素地球化学特征

Geochemistry of trace elements in sediments from the China Pioneer Area, northeast equatorial Pacific Ocean

分析了中国多金属结核开辟区沉积物中Ba、Ce、Co、Cr、Cu、Mo、Ni、Sr、V、Y和Zn等11个微量元素的含量。研究表明,开辟区沉积物中微量元素在不同沉积单元中的分布特征存在明显差异,反映了地质历史上沉积环境的不同。沉积物中的Zn、Ni与Mn具有共同来源,反映铁锰氧化物、氢氧化物对这些元素的吸附控制作用;Sr、Ba以及Ce和Y等元素在东区主要与岩源碎屑有关,而西区则主要来自生物碎屑;Cu具有多种来源,东区主要与生物组分和岩源碎屑有关,西区则主要与自生铁锰氧化物的吸附有关。而通常认为与有机物有关的Cr、V等元素在研究区内则主要来自岩源碎屑。

Deep sea sediment samples from the China Pioneer Area for ferromanganese nodules in the northeast equatorial Pacific are analyzed for elements Ba, Ce, Co, Cr, Cu, Mo, Ni, Sr, V, Y and Zn. There are remarkable differences of the distribution of these elements in the different sediments units and different areas. This perhaps suggests that the sediment environment is different in history. The concentration depth profiles of Cu, Co, Ni and Zn are very similar to the MnO2 depth profiles in the research zones. Combined to the correlation analysis, it is found that Zn, Ni and Mn have a common origin, and are influenced by the adsorption of iron manganese oxides. However, copper perhaps has several sources in the research zones, and presents different features in the East Area and the West Area, respectively. It mainly is correlated with biogenic debris and terrigenous component in the East Area. But it is correlated with iron manganese oxides remarkably in the West Area. Sr, Ba, Ce and Y are mainly correlated with terrigenous components in the East Area, nevertheless biogenic debris controls their distributions in the West Area. The distribution of Cr and V is controlled by the weathering of terrigenous debris, and has no correlation with organic matter in sediments.