太原西山地区石炭-二叠纪沉积环境演化

Sedimentary Environmental Evolution of Carboniferous-Permian in Taiyuan Xishan

利用野外露头、剖面、钻孔岩心等对太原西山地区石炭-二叠纪地层沉积相进行分析,识别并总结出台地-泻湖、障壁岛-泻湖-潮坪、浅水三角洲和河流4大沉积体系以及若干沉积相类型。该区晚石炭世本溪组沉积期主要发育台地-泻湖沉积体系;晚石炭世-早二叠世太原组沉积期以障壁岛-泻湖-潮坪的障壁海岸沉积体系为主,其次发育碳酸盐台地相和沼泽相。早二叠世山西组沉积期及以后,整个地区发生区域性海退,以浅水三角洲和河流沉积体系广泛发育为特征。沉积环境的演化经历了早期的陆表海、中期海陆过渡沉积和晚期的三角洲、陆相河流沉积,聚煤作用发生于太原组和山西组沉积期。

Based on the analysis of field outcrop, section, drilling core and other the sedimentary facies marks in the Carboniferous -Permian strata of Taiyuan Xishan area , four sedimentary systems and some sedimentary facies are identified, including platform - lagoon, barrier- lagoon -tidal flat, shallow water delta and fluval deposit. According to the study, Platform - lagoon depositional system is mainly developed in the Benxi Formation of the lat- er carboniferous epoch in this region. In the late carboniferous to the early Permian Taiyuan formation, barrier -la- goon -tidal flat on the barrier coast is given priority to, and the second is carbonate platform and swamp facies. Early Permian Shanxi formation and beyond, regional regression happens in the entire district with the shallow water delta and fluvial sedimentary system characterized by extensive development. The evolution of the sedimentary envi- ronment experienced the early epeiric sea, middle sea and land transition and late delta and continental fluvial sedi- ment. The coal accumulation occurred in the Taiyuan and Shanxi formation.