东太平洋CC区多金属结核铂族元素(PGE)地球化学及其意义  

Platinum group elements (PGE) geochemistry of polymetallic nodules in CC zone, east Pacific Ocean

作　　者：何高文[1,2] 孙晓明[1,3] 杨胜雄[4] 薛婷[1] 宋成兵[4] 石贵勇[1] 张美[1] 韩喜球[5] 

机构地区：[1]中山大学地球科学系 [2]国土资源部广州海洋地质调查局,广东广州510075 [3]中国科学院广州地球化学研究所南海海洋研究所边缘海地质重点实验室,广东广州510640 [4]国土资源部广州海洋地质调查局 [5]国家海洋局第二海洋研究所

出　　处：《矿床地质》2006年第2期164-174,共11页Mineral Deposits

基　　金：中国大洋协会国际海底区域研究开发"十五"计划项目(DY105_01_02_1和DY105_2_01_13);国家自然科学基金(40343019和40473024);中科院广州地球化学研究所南海海洋研究所边缘海地质重点实验室开放基金(MSGLCAS03_4);高等学校博士点基金(20040558049);国土资源部百名优秀青年科技人才计划的联合资助

摘　　要：文章采用火试金分离富集法和等离子发射光谱(ICP_MS)测定了东太平洋CC区多金属结核中PGE和Au元素的含量,结果显示:结核中PGE相对于洋壳明显富集,尤其是Pt含量较高,wPt平均值为100.90×10-9。各种类型的多金属结核PGE和Au的球粒陨石配分曲线及有关参数非常一致,均表现为Pt正异常和Pd负异常,显示其中PGE和Au具有相似的来源。多金属结核与海底海山富钴结壳PGE配分模式及特征元素比值对比表明,两者PGE可能具有相同的来源,可能主要来源于海底玄武岩的水岩反应,部分来源于铁陨石,而并非主要来自海底热液及正常海水。The platinum-group elements and Au concentrations of polymetallic nodules from the CC zone of East Pacific Ocean were determined by a combined NiS fire assay and ICP-MS method, in which PGE were preconcentrated and then measured by ICP-MS. The nodules are enriched with more PGEs than the oceanic crust. Pt, in particular, reaches a high concentration with an average of 100.90 ×10^-9 in nodules. Different types of nodules have quite similar PGE and Au chondrite-normalized patterns and related parameters, with positive Pt and negative Pd anomalies, indicating that PGE and Au in different types of nodules have the same sources. Besides, the similar PGE chondrite-normalized patterns and element ratios between seamounts cobaltrich crusts and nodules suggest that they may also have similar sources of PGE, perhaps derived mainly from seawater-rock interaction in submarine basalt and partially from iron meteorite, but not directly from submarine hydrothermal sulfides and seawater.

关 键 词：地球化学 多金属结核 铂族元素(PGE)和Au 富钴结壳 成矿物质来源 东太平洋CC区 

分 类 号：P618.53[天文地球—矿床学]