长江口及邻近海域悬浮颗粒重晶石特征与成因探讨

发布时间：2018-12-20 21:54

【摘要】：海洋环境中重晶石的形成和保存是元素Ba生物地球化学过程的重要环节,在反演海洋古生产力领域具有重要价值。但是多年来该方面的研究主要集中在深海海域,而对河口及近海海域很少涉及。本研究使用SEM和EDX等方法对长江口及邻近海域5个断面36个站位的悬浮体中的重晶石矿物进行了系统的观察,对重晶石颗粒类型、空间分布和影响因素进行了研究。结果表明:该区重晶石颗粒包含自形晶体、长条状晶体、不规则形态晶体和集合体等4种类型,含少量Sr元素,大部分重晶石颗粒表面出现溶蚀现象;重晶石颗粒粒径主要分布在0.5~3μm。通过研究发现,长江口及邻近海域悬浮体中重晶石的形成主要受到微环境中生物作用的控制,该区初级生产力的发育状态和重晶石颗粒的沉降差异造成重晶石空间分布具有表层含量较多、由岸向外增加的现象。
[Abstract]:The formation and preservation of barite in marine environment is an important link in the biogeochemical process of element Ba, which is of great value in the field of inversion of marine paleoproductivity. However, for many years, the research has focused on the deep sea area, but rarely on the estuary and offshore area. In this study, the barite minerals in 36 suspensions of 5 sections in the Changjiang Estuary and its adjacent waters were systematically observed by means of SEM and EDX, and the types, spatial distribution and influencing factors of barite particles were studied. The results show that there are four types of barite particles in this area, such as self-shaped crystals, long stripe crystals, irregular crystals and aggregates, with a small amount of Sr elements, and the surface of most barite particles is dissolved. The particle size of barite is mainly distributed at 0.5 渭 m. It is found that the formation of barite in the suspension of the Changjiang Estuary and its adjacent waters is mainly controlled by the biological action in the microenvironment. The development state of primary productivity and the difference of barite particle settlement in this area result in the spatial distribution of barite with more surface content and increase from shore to outside.
【作者单位】：中国海洋大学海洋地球科学学院海底科学与探测技术教育部重点实验室;
【基金】：国家自然科学基金项目(41376055) 国家重点基础研究发展计划(973计划)项目(2010CB951202)~~
【分类号】：P736.4

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