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。
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.
出处
《沉积与特提斯地质》
CAS
CSCD
2017年第1期79-87,共9页
Sedimentary Geology and Tethyan Geology
基金
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)
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
Early Silurian
sedimentary facies
sedimentary evolution
Longmaxi Formation
black shale
sedimentary model
