中国石油大学学报（自然科学版）2017，Vol.41Issue(1)：34-41,8.DOI:10.3969/j.issn.1673-5005.2017.01.004
焦石坝五峰组-龙马溪组页岩硅质生物成因的证据及其地质意义
Evidences of biogenic silica of Wufeng-Longmaxi Formation shale in Jiaoshiba area and its geological significance
摘要
Abstract
Based on the elemental content of the ground outcrop samples and the drilling cutting samples,combined with the observation of core and thin section,the evidences of biogenic silica of Wufeng-Longmaxi Formation shale in Jiaoshiba area were analyzed,and the geological significance was discussed as well.The results show that there are a lot of paleontological fossils,such as graptolite,oncoceras,coral,and a lot of microfossils,such as radiolarian,in Wufeng-Longmaxi Formation shale.The content of SiO2 is between 40％ and 80％,about 63％ on average.The content of the assess SiO2 is between 2.6％ and 55.31％,and the contents in Wufeng Formation and the lower member of Longmaxi Formation shale are higher,which are up to 41.3％ and 25.5％ on average respectively.The value of Al/(Al+Fe+Mn) is between 0.62 and 0.87,which is close to the value of pure biogenic siliceous rocks.In the triangular Al-Fe-Mn diagram,most of the samples locating in the biogenic silica area indicate the silica of Wufeng-Longmaxi Formation shale is biogenic.High content of biogenic silica indicates deep-water shelf,hypoxic or anaerobic sedimentary environments is beneficial of enrichment of organic material and formation of organic pores,which shows important significance to the formation of natural fracture and the later artificial fracturing.关键词
焦石坝/五峰组-龙马溪组/页岩/硅质生物成因/地质意义Key words
Jiaoshiba area/Wufeng-Longmaxi Formation/shale/biogenic silica/geological significance分类
天文与地球科学引用本文复制引用
刘江涛,李永杰,张元春,刘双莲,蔡英杰..焦石坝五峰组-龙马溪组页岩硅质生物成因的证据及其地质意义[J].中国石油大学学报（自然科学版）,2017,41(1):34-41,8.基金项目
中国石化重点科技攻关项目(P13012) （P13012）
