中太平洋富钴结壳Co元素地球化学特征

Cobalt geochemistry features in Co-rich crust in the central Pacific Ocean

对在中太平洋研究区5座海山调查时获取的38个富钴结壳样品中主要金属元素的含量进行了化学分析,探讨了不同海山富钴结壳中Co元素含量的变化规律及结壳中元素间的相关关系,结果表明:(1)5座海山富钴结壳中的各主要金属元素含量相近,38个富钴结壳样品中Co元素的平均含量为0.67%,具有一定的开发前景。(2)不同海山富钴结壳中Co元素含量有一定变化,其变化与富钴结壳的类型、海水水深、地形地貌以及成矿作用等有密切的关系。Co元素在板状结壳中的含量为最高,在钴结核中的含量次之,而在砾状结壳中的含量为最低;富钴结壳中Co元素含量与海水水深呈负相关,浅水区富钴结壳中Co元素的含量明显高于深水区;海山地形地貌对Co元素的含量及富钴结壳的发育有一定影响,海山的椭圆状分支、支脉及边缘部分,Co元素的含量相对较高,富钴结壳发育得较好;Co元素富集成矿作用还主要受锰、铁水成成矿作用的控制。(3)富钴结壳中金属元素之间存在不同程度的相关性。Mn元素分别与Co、Ni、Cu、Zn、Mg、Na、Ba、Ti等元素呈强烈的正相关,而分别与Al、Si、Ca、P、Fe、Sr等元素呈负相关;Co元素分别与Cu、Al、P、Ca等元素呈负相关;Ca元素与P元素呈强烈正相关。

The paper discussed the content of main mineralizing metals of the crusts in the research areas and relations between the content of cobalt, type of crust, water depth and other elements, by comparing with the content of cobalt from various seamounts. The results indicate: (1)In the Co\|rich crust from different seamounts, the concentration of cobalt varies in a wide rang. (2) Based on the statistical analysis, changes in the content of cobalt from different crusts indicate: slabby crust>nodulous crust>gravel crust. (3) The concentration of Co is related to water depth, topography and mineralization. (4) In the crust, Mn is obviously positively correlated to Ni, Zn, Mg, Na, Co, and negatively to Al, Si, Ca, P, Fe. Ca is clearly positively correlated to P.