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峡东震旦系为缓坡型台地碳酸盐岩沉积序列。陡山沱组从下至上发育内缓坡相的潮上带 潮间带含膏盐塞卜哈、环潮坪碳酸盐岩和陆源碎屑岩混积以及中外缓坡相潮间带—潮下带和盆地相沉积。灯影组发育内缓坡相带内的各种沉积亚微相序列,沉积亚微相型复杂多样,为碳酸盐海滩沉积,垂向序列上发育“对偶砂滩坝”微相,即下部蛤蟆井段为潮间下—潮下碳酸盐鲕滩,中下部石板滩段为向上变浅、变细的滩后潮间澙湖沉积,中上部白马坨段为滨岸带碳酸盐砂滩坝与环潮坪沉积。碳酸盐岩地球化学研究表明,Mn/Sr比值从浅滩相(2.0到0.1～0.5),内缓坡塞卜哈(1.0)至滩后(0.4～0.8)和中外缓坡(0.1～0.5)具有双峰式分布特点。δ~(18)O、δ~(13)C和稀土元素组成分析表明,白云岩以准同生成因为主。潮间带以下的微相稀土总量最为丰富,近岸的浅滩、潮汐流浅滩和滩后澙湖等最低,变浅、暴露以及干燥蒸发微相中普遍表现Eu的亏损,随着环境由深到浅的微旋回变化表现着δCe的明显减少和δEu的相对减低。
Giandong Sinian is a gentle slope platform carbonate sedimentary sequence. The Doushantuo Formation developed from bottom to top in the tidal zone with intertidal facies, including the salt-bearing Sabha, tidal flat carbonate and terrigenous clastic rocks, Sedimentary and basin deposition. The Dengying Formation developed various sedimentary sub-micro-facies sequences in the intra-gentle ramp facies, and the sedimentary sub-micro-facies types are complex and diverse. They are carbonate beach deposits and vertical series of “dual sandbank” micro-facies, ie, the lower frog The segment is the intertidal-infratemporal carbonate oolitic beach, and the middle and lower part of the slate is upwardly shallow and thinning. The Baimao section in the middle and upper part is the carbonate sand beach dam with ring Tidal flat sediments. Carbonate geochemistry shows that the ratio of Mn / Sr is from double to shallow (2.0 to 0.1 ~ 0.5), the inner gentle slope Sabha (1.0) to the back of the beach (0.4 ~ 0.8) Peak distribution characteristics. The δ 18 O, δ 13 C and REE compositional analyzes show that the dolomites are mainly derived from the quasi - formation. The amount of rare earths below the intertidal zone is the most abundant, with the lowest, shallow, exposed and dry evaporimetric microfacies of the nearshore shoal, tidal shoal shoal and tundra shoal lake generally showing the depletion of Eu. As the environment goes deeper Microtary changes to shallow show a significant decrease in δCe and a relative decrease in δEu.