湘南地区寒武系沉积环境分析

湘南地区寒武系自下而上依次发育香楠组、茶园头组、小紫荆组。岩石类型主要以碎屑岩为主,碳酸盐岩、硅岩次之。其中,砂岩与泥(页)岩常构成典型的复理石韵律。通过对岩性、古生物、沉积构造等相标志的分析,认为研究区寒武系沉积环境主要为深水斜坡至盆地环境,建立了沉积模式并分析了其沉积演化。区内寒武纪经历了3次海侵,第一次海侵始于早寒武世晋宁期,结束于南皋期;第二次海侵始于都匀期,结束于王村期;第三次海侵出现于古丈期,至牛车河期结束。

An analysis of the Cambrian sedimentary environment in southern Hunan Province

The Cambrian strata in southern Hunan can be divided from bottom to top into Xiangnan Formation, Chayuantou Formation and Xiaozijing Formation. The rock types are mainly clastic rock and subordinately carbonate rock and siliceous rock, in which sandstone and mudstone(shale)often form typical flysch rhythms. Based on a comprehensive study of such facies indicators such as lithologic character, palaeobiologic fossils and sedimentary structure, the authors hold that the Cambrian sedimentary environment of the study area was a deep-water slope to basin environment. The sedimentary environment evolution was analyzed and the sedimentary model was set up. The area experienced three transgression events during Cambrian. The first transgression began in the Jinning stage and ended in the Nangao stage. The second transgression began in the Duyun stage and ended in the Wangcun stage. The third transgression began in the Guzhang stage and lasted until the Niuchehe Age.