南海琼东南海域沉积物的微量元素地球化学特征及其对天然气水合物的指示意义

发布时间：2018-02-28 01:30

本文关键词： 微量元素海洋沉积物硫化氢天然气水合物琼东南海域　出处：《海洋地质与第四纪地质》2017年05期 　论文类型：期刊论文

【摘要】：天然气水合物已成为重要的战略资源。为探讨天然气水合物富集区的微量元素特征及其指示意义,对琼东南海域沉积物进行系统采样,分析了样品主、微量元素和TOC地球化学特征,并采用氧化还原状态以及氧化还原敏感元素与TOC相关关系的分析方法进行探讨。结果显示:沉积物相较于上地壳更为富集Sr、Pb、Th、U、Zn、Cu和Mo元素,Th/U和V/Sc比值在纵向上呈系统的变化,表层沉积物处于还原的沉积状态,大量富集Mo和U。初步推断研究区部分沉积物可能处于硫化带,使其出现氧化还原敏感元素(Mo和U)的富集,这些特征或由下部天然气水合物分解释放大量的甲烷所导致。表层沉积物孔隙水中出现的硫化带以及Mo和U元素异常,可作为新的地球化学指标以识别下部可能存在的天然气水合物资源。
[Abstract]:Natural gas hydrate has become an important strategic resource. In order to study the trace element characteristics of gas hydrate rich area and its indicative significance, the sediment of southeast Hainan was sampled systematically, and the main samples were analyzed. Trace elements and TOC geochemical characteristics, The relationship between the redox state and the relationship between the redox sensitive elements and TOC is discussed. The results show that the ratios of Th / U and V / SC in the sediments are more enriched than those in the upper crust. The surface sediments are deoxidized and enriched with Mo and U.The preliminary conclusion is that some of the sediments in the study area may be in the sulphide zone, resulting in the enrichment of redox sensitive elements such as Mo and U). These characteristics may be caused by the decomposition and release of a large amount of methane from the lower part of the gas hydrate. The sulphide zone and the anomalies of Mo and U elements in the pore water of the surface sediments, It can be used as a new geochemical index to identify the potential gas hydrate resources in the lower part.
【作者单位】：国土资源部海底矿产资源重点实验室;中国地质调查局广州海洋地质调查局;南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室;中山大学海洋科学学院;
【基金】：国土资源部海底矿产资源重点实验室项目(KLMMR-2015-A-03,KLMMR-2013-A-24) 中国地质调查局项目(GZH201100303) 科技部“973”项目(2013CB835004)
【分类号】：P736.2;P744.4

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