岩石矿物学杂志2017，Vol.36Issue(2)：213-226,14.
扬子板块北缘下志留统龙马溪组重晶石结核特征及其成因机制分析
An analysis of barite concretions from lower Silurian Longmaxi Formation on the northern margin of the Yangtze block and their genetic mechanism
摘要
Abstract
Barite concretions were found in siliceous rocks and mudstones in the lower Silurian Longmaxi Formation on the northern margin of the Yangtze block.Their mineral compositions are barite crystals,pyrite,clay or quartz.Based on an analysis of the macroscopic and microscopic morphology of barite and strontium isotopes,the authors hold that barite deposits precipitated from the enclosed pore water in sedimentary column.The high productivity and anoxic bottom water provided the environment for the formation of barite.Bio-barite could be formed by biological effect in the seawater.Afterwards,bio-barite was dissolved by sulfate bacteria (BSR) in the sulfate depleted zones.Sulfate in pore water was evolved from the penecontemporaneous seawater.The host mudstone indicates high preservation potential in an anoxic depositional environment.This study has provided some implications for the further understanding of the paleoenvironment of the northern margin of the Yangtze block in early Silurian.关键词
扬子板块/下志留统/龙马溪组/重晶石结核Key words
Yangtze block/lower Silurian/Longmaxi Formation/barite concretions分类
天文与地球科学引用本文复制引用
昝博文,刘树根,冉波,叶玥豪,杨迪,黄瑞,夏国栋,焦堃..扬子板块北缘下志留统龙马溪组重晶石结核特征及其成因机制分析[J].岩石矿物学杂志,2017,36(2):213-226,14.基金项目
中国地质调查项目(121220115003801-04)China Geological Survey Project(121220115003801-04) （121220115003801-04）
