鄂西地区陡山沱组页岩段有机质富集的差异性

摘要

This paper discusses the differences about the organic matter enrichment in the shale section of the Ediacaran Doushantuo Formation in West Hubei and analyses the outcrops, geology and geochemistry. The results show that the main sedimentary environment includes tidal flats, shelf lagoon, shelf margin and slope. The black shale develops in the shelf lagoon, and the dolomite in the tidal flats. The black shale of the Doushantuo Formation in West Hubei region develops in Segment B and D, and the TOC value (mass fraction) is mostly higher than 2% , and the TOC value in Segment D higher than segment B. The differences about TOC value depend on different sedimentary environments. The water power, paleosalinity and oxidation reduction environment can reflect the differences of the sedimentary environment. The results can guide the exploration of shale gas.%探讨鄂西地区下震旦统陡山沱组黑色页岩段有机质富集的差异性.通过鄂西地区陡山沱组野外露头、地质、地球化学综合研究分析,结果表明鄂西地区陡山沱组沉积环境主要为潮坪、台内盆地、台缘浅滩和斜坡.黑色页岩段主要发育于台内盆地,而潮坪主要发育白云岩；鄂西地区陡山沱组黑色页岩发育于B段和D段,其TOC的质量分数大多数＞2％,D段TOC的质量分数高于B段,两者相差3％,这种差异与页岩形成的沉积环境密切相关.环境的差异性表现为水体动力条件、古盐度环境和氧化-还原环境的地球化学指标差异.