摘要: |
受加里东运动影响,湖南下志留统地层主要分布在湘西北和湘中-湘南地区。随着构造运动、盆地演变和海平面下降,湖南早志留世岩相古地理也发生了巨大的变化。综合露头剖面、钻井岩心和岩石薄片的观察,结合数据分析和前人研究成果,在下志留统识别出比较典型的沉积相:湘西北主要发育陆棚、潮坪、三角洲等浅海相,湘中-湘南主要为深水浊积岩相。文中恢复了下志留统沉积演化,分析了龙马溪组黑色页岩发育特征及其受控因素,建立了页岩沉积模式。 |
关键词: 早志留世 沉积相 沉积演化 龙马溪组 黑色页岩 沉积模式 |
DOI: |
附件 |
投稿时间:2016-09-15修订日期:2016-11-18 |
基金项目:中国地质科学院地质力学研究所研究项目《南方地区构造演化与页岩气分布调查》(12120115007301) |
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Sedimentary evolution and shale gas exploration potential of the Lower Silurian strata in Hunan |
Xiao-Pan, GUO Jian-hua, LI Jie, WANG Zhang-hu, WANG Xi-kai |
(1. Key Laboratory of Metallogenetic Prognosis of Nonferrous Metallic Deposits, Central South University, Changsha 410083, Hunan, China; 2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, Hunan, China) |
Abstract: |
The Lower Silurian strata are developed in the northwestern and central-southern parts in Hunan. The representative sedimentary facies may be classified into the shelf, tidal-flat and delta facies in the northwestern part, and the deep-water turbidite facies in the central-southern parts in Hunan. Controlled by the tectonic movements, sea-level changes and sediment supply, the black shales in the basal part of the Silurian strata are restricted only in the shallow-sea environments in the northwestern part of Hunan, where the shales, sandy shales and argillaceous sandstones are observed. The organic carbon contents generally vary between 0.12% and 3.86%, and maximum organic carbon contents occur in the Longshan-Yongshun zone. The organic carbon contents and the thickness of the source rocks sharply decrease toward the southeastern part of Hunan. |
Key words: Early Silurian sedimentary facies sedimentary evolution Longmaxi Formation black shale sedimentary model |