摘要
通过生物地层、年代地层、岩石地层的研究,对四川盆地二叠系进行重新划分。四川盆地生物组合与中国南方海相生物具有可对比性,同属一个生物大区,但生物地层发育不全。下二叠统仅在龙门山局部地区残存,厚度较小,盆地内普遍缺失;中二叠统下部缺失第一个蜓带,冷坞阶在盆地内大部分地区缺失。与原划分方案相比,P/C界线由原不整合接触变为连续沉积,P1/P2及P2/P3之间均为区域不整合接触,P/T之间为连续沉积。从岩石地层与年代地层的关系看,栖霞组包含了栖霞阶及祥播阶下部,茅口组包含了祥播阶上部、茅口阶及冷坞阶,龙潭组对应于吴家坪阶,长兴组对应于长兴阶。
With study on biological stratigraphy, geochron stratigraphy, and lithologic stratigraphy, Permian is re-divided in Sichuan Basin. The biological composition in Sichuan basin is comparable with the marine biological composition in south China. They belong to the same big biological region. But the biological strata develop incompletely in Sichuan Basin. The lower Permian exists only in the local area of Longmenshan and its thickness is small. It is missing commonly in the basin. The first fusulinid belt is missing in the down of Middle Permian. Lengwu stage is missing in most areas of the basin. Comparing with the original dividing program, P/C boundary becomes continuous deposition from the original unconformity, both boundaries of P_1/P_2 and P_2/P_3 are regional unconformity, and P/C boundary is continuous deposition. According to the relationship between geochron stratigraphy, and lithologic stratigraphy, Xixia Formation includes Xixia stage and down Xiangbo stage; Maokou Formation includes up Xiangbo stage, Maokou stage and Lengwu stage; Longtan Formation is corresponding to Wujiaping stage and Changxing Formation is corresponding to Changxing stage.
出处
《天然气勘探与开发》
2005年第3期20-25,共6页
Natural Gas Exploration and Development
基金
中国石油天然气股份有限公司"十五"重点科技攻关项目<四川油气区石炭-二叠系划分对比
古环境研究及含油气远景评价>部分成果。
