摘要
通过对"世界硒都"恩施地区出露广泛的31个岩石地层单位(组)岩石采样检测发现,最富硒地层为二叠系孤峰组—大隆组,主要出露于恩施中东部和北部,其次为寒武系牛蹄塘组和奥陶—志留系龙马溪组,主要出露于恩施中南部;岩石硒元素与有机碳含量呈明显正相关,不同岩性岩石中硒元素富集规律为黑色岩系(碳硅质页岩)>煤层>碳酸盐岩(灰岩、白云岩)>泥岩>砂岩。探讨了富硒地层分布的控制因素,认为拉张性的大地构造背景下,深部硒元素易沿深大断裂或火山活动来到地表,并被同期浅海滞留盆地或深水陆棚等还原环境下沉积的大量有机碳吸附,完成主要富硒地层中硒元素沉积—同生阶段的源与汇。
Through rock sampling and testing of 31 lithostratigraphic units(formations)widely exposed in Enshi area of"Se Capital"in the world,it is found that the most selenium-rich formations are Permian Gufeng-Dalong formations,mainly exposed in the central and northern part of Enshi.Next are the Cambrian Niujitang Formation and the Ordovician-Silurian Longmaxi Formation,which mainly occur in the south-central part of Enshi.Selenium content in rocks is positively correlated with organic carbon content.Selenium enrichment regularity in rocks of different lithologies is as follows:black rock series(carbonaceous siliceous shale)>coal bed>carbonate rock(limestone,dolomite)>mudstone>sandstone.The controlling factors of selenium-rich strata distribution are discussed.It is considered that deep selenium is easy to come to the surface along deep faults or volcanic activities in extensional tectonic setting,and is adsorbed by a large amount of organic carbon deposited in reductive environments such as shallow-sea detained basins or deep-water continental shelves at the same time,thus completing source and sink of selenium deposition in the main selenium rich formations.
作者
李明龙
徐辉
许克元
陈发俊
唐成
杨登银
Li Minglong;Xu Hui;Xu Keyuan;Chen Fajun;Tang Cheng;Yang Dengyin(Second Geological Brigade of Hubei Geological Bureau,Enshi,Hubei 445000)
出处
《资源环境与工程》
2018年第4期557-562,共6页
Resources Environment & Engineering
基金
恩施州科技计划项目"恩施州富硒地层分布规律研究"(项目编号:2013014)资助
关键词
富硒地层
富集规律
控制因素
孤峰组
恩施
Se-rich strata
enrichment regularity
controlling factors
Gufeng Formation
Enshi
