南海北部铁锰结核成因及元素的赋存状态

发布时间：2018-06-30 04:33

本文选题：铁锰结核 + 赋存状态　；参考：《热带海洋学报》2017年02期

【摘要】：为了解南海北部不同海域铁锰结核中常微量、稀土元素的赋存特点及其富集机制,采用化学淋滤法提取南海北部上陆坡、下陆坡、深海盆3个区域铁锰结核的碳酸盐相、铁锰氧化相、残渣相组分,测定了常微量元素、稀土元素含量,揭示了不同相的元素赋存状态及其意义。Fe-Mn-(Cu+Co+Ni)判别图表明,上陆坡铁锰结核属于与冷泉流体相关的水成成因类型;下陆坡区和深海盆的铁锰结核形成环境相似,属于典型的水成成因类型。结核中K、Ca、Na、Mg、Sr主要富集在碳酸盐相,Fe、Mn、Ni、Cu、Zn、Pb主要赋存在铁锰氧化物相,Al、Ti和Mo主要出现在残渣相。常微量元素赋存状态变化受多种因素影响,钙质生物生产力的强弱和钙质生物碎屑的稀释作用是影响铁锰结核中碳酸盐相态元素变化的重要原因。铁锰结核的稀土元素主要富集在铁锰氧化物相,其次在碳酸盐相,而在残渣相的相对含量极少。不同海区铁锰结核稀土元素进入碳酸盐相的成因和机制基本相似,下陆坡和深海盆铁锰结核残渣相稀土元素配分模式相似,而与上陆坡铁锰结核的明显不同,残渣物质的来源、结核生长环境的氧化还原状态差异是主要影响因素。研究成果可为深入研究铁锰结核的元素迁移与转化、成矿作用与成矿物质来源及其相关的沉积环境、资源潜力评价等提供重要的基础资料。
[Abstract]:In order to understand the characteristics and enrichment mechanism of common trace and rare earth elements in ferromanganese nodules in different sea areas of the northern South China Sea, the carbonate facies of iron manganese nodules in three regions of the northern South China Sea were extracted by chemical leaching method, including upper and lower continental slopes and deep sea basins. The contents of trace elements and rare earth elements in iron and manganese oxidation phase and residue phase were determined, and the occurrence states of elements and their significance in different phases were revealed. The results of Fe-Mn- (Cu Co Ni) discriminant diagram showed that the contents of trace elements and rare earth elements in different phases were determined. The ferromanganese nodules on the upper slope belong to the hydrogenetic type related to the cold spring fluid, and the ferromanganese nodules in the lower slope area and the deep sea basin are similar in forming environment and belong to the typical hydrogenetic type. In the nodules, the K _ (+) Ca ~ (2 +) Na ~ (2 +) mg ~ (+) Sr is mainly enriched in the carbonate phase Fehmann\ +\%\? The change of the occurrence state of trace elements is affected by many factors. The strength of calcareous biological productivity and the dilution of calcareous bioclastic materials are the important factors influencing the changes of carbonate phase elements in ferromanganese nodules. The rare earth elements of ferromanganese nodules are mainly enriched in the ferromanganese oxide phase, then in the carbonate phase, and the relative content in the residual phase is very little. The origin and mechanism of rare earth elements entering carbonate facies in different sea areas are basically similar, and the REE distribution pattern of iron manganese nodule residue phase in lower continental slope and deep sea basin is similar, but is obviously different from that in upper continental slope, and the source of residual material is different from that of iron manganese nodule in upper continental slope. The difference of redox state in nodule growing environment is the main influencing factor. The results can provide important basic data for further study on element migration and transformation, metallogeny and source of ore-forming material and related sedimentary environment, and evaluation of resource potential of Fe-Mn nodules.
【作者单位】：中国科学院南海海洋研究所中国科学院边缘海地质重点实验室;中国科学院大学;
【基金】：国家自然科学基金项目(41376057;41676056;41306047)~~
【分类号】：P744.3

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