中太平洋WM1和WX海山富钴结壳元素相关性及其层间变化研究  

A study of elemental correlation and elemental variation in different layers of the Co-rich crusts from the Mid-Pacific WM1 and WX seamounts

作　　者：佟景贵[1] 王吉中[2] 初凤友[3] 李胜荣[1] 方念乔[1] 吴敏[1] 牛花朋[1] 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室 [2]石家庄经济学院资源学院,河北石家庄050031 [3]国家海洋局第二海洋研究所海底科学重点实验室,浙江杭州310012

出　　处：《岩石矿物学杂志》2007年第2期155-163,共9页Acta Petrologica et Mineralogica

基　　金：国家大洋专项重点研究课题(DY105-01-01-01;DY105-01-04-14)

摘　　要：在结壳矿物学等基本特征分析的基础上,对中太平洋WM1和WX海山富钴结壳中的主量元素、微量元素、稀土元素和铂族元素含量、层间变化及其相关性进行了研究,结果表明:本区结壳从下层到上层,粘土矿物和石英等碎屑矿物逐渐增多,很可能与青藏高原的隆升和剥蚀以及亚洲季风演化有关;TFe/Fe2+从结壳下层到上层逐渐增高,反映了结壳的氧化性由下层到上层增强,海山的沉降可能是造成结壳生长后期环境氧化性增强的重要原因;Ti、Co、Pb、As、Mn、TFe等元素与TFe/Fe2+呈正相关,反映结壳中这些元素的富集与氧化环境有关,而Ca、P、Pt和∑REE等元素与TFe/Fe2+呈负相关,反映结壳中这些元素的富集与还原环境有关;Fe与Co显著正相关是本区结壳的重要特点;结壳的Co与(Fe+Mn)的相关性大于Co与Fe的相关性及Co与Mn的相关性;P含量小于1%时,Co与P相关性不明显,当P含量大于1%时,Co与P呈明显负相关,磷酸盐化的过程对铁锰结壳吸附Co的能力起到抑制作用。聚类分析将Pt、∑REE与P和Ca分为一组,说明在结壳中Pt和∑REE主要赋存在碳氟磷灰石中,结壳的磷酸盐化的过程对Pt和∑REE的富集起到了重要的作用。The elemental correlation in Co-rich crusts from the Mid-Pacific WM1 and WX searnounts and elemental variation in different layers of the crusts were studied in this paper. Some conclusions have been reached： 1） the amount of hydrosyalite and quartz increases gradually from the lower layer to the upper layer, which is probably related to the evolution of Asian monsoons and the uplift of the Himalayan-Tibetan plateau; 2） the increase of the ratio of TFe/Fe^2＋ from the lower layer to the upper layer indicates that the oxidation of the crusts also increases correspondingly, which may be caused by the sinking of the seamounts;3） the positive correlation between the values of TFe/Fe^2＋ and the contents of Co, Pb, As, Mn and Fe shows that these elements occur in an oxidization enviroument, whereas the negative correlation between the values of TFe/Fe^2 ＋ and the contents of Ca, P, Pt and ∑ REE suggests that these elements occur in a reduction environment; 4） the remarkable positive correlation between Fe and Co in these crusts is different from things of the crusts in other places, which is an unique crustal feature of this zone;5） the correlation between Co and （Fe ＋ Mn） is greater than that between Co and Fe as well as Co and Mn; 6） P and Co almost have no correlation when the content of P in the crusts is below 1%, but they are notably negatively correlated with each other when the content of P is above 1%, which means that the enrichment of P restrains the adsorption of Co by crusts; 7） the elements of Pt, ∑REE, and Ca are assigned to the same group by cluster analysis, suggesting that Pt and ∑REE occur in carbonate fluorapatite, and that phosphatization plays an important role in the enrichment of Pt and ∑REE.

关 键 词：中太平洋 富钴结壳 元素相关性 层间变化 

分 类 号：P578.4[天文地球—矿物学] P595[天文地球—地质学]