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报道了贵州江口桃映深水相剖面陡山沱组碳酸盐岩δ13C值的变化特征,结合其他已报道的数据,分析了华南扬子地区埃迪卡拉纪陡山沱海洋不同沉积环境,包括盆地相、斜坡相、台地相、台地边缘相碳酸盐岩中δ13C变化趋势及绝对值的异同,发现浅水区剖面记录的δ13C漂移次数多于深水区剖面,且不同相区δ13C值也有差异。δ13C值的差异与埃迪卡拉纪陡山沱海洋的阶段性演化密切相关。基于不同相区的δ13C值变化,埃迪卡拉纪陡山沱海洋的演化历史可分为3个时期:1)陡山沱组1段盖帽白云岩沉积期华南扬子地区很可能为一个开阔台地,白云岩中δ13C值可能继承于幔源CO2的碳同位素特征,深水区和浅水区碳酸盐中δ13C值无显著差异;2)陡山沱组2段和陡山沱组3段下部沉积时期盆地深水区中δ13C值显著低于浅水区,且深水区δ13C值与陡山沱组1段时期无显著差异,浅水区的δ13C值则显著升高;3)陡山沱组3段上部和陡山沱组4段沉积时期陡山沱盆地中δ13C值均显著下降,且不同沉积环境中的δ13C值差异度降低。盖帽后埃迪卡拉纪陡山沱海洋阶段性演化主要与不同时期深水区DOC库的逐步氧化有关。
This paper reports the δ13C values of the Doushantuo carbonate rocks in the Taoying deep water facies section of Jiangkou, Guizhou. Based on the other reported data, the different sedimentary environments of the Doushantuo Edicarca in the Yangtze River Basin, including the basin facies , Δ13C variation trend and absolute value of carbonate rocks in the margin facies, platform facies and platform marginal facies, and found that the δ13C drifts recorded in the shallow water section are more than those in the deepwater section, and the δ13C values in different facies are also different. The difference of δ13C value is closely related to the stage evolution of the Doushantuo Ediacaran Ocean. Based on the variations of δ13C values in different facies zones, the evolution history of the Edoukaragami Doushantuo ocean can be divided into three periods: 1) the Doushantuo Formation 1 cap dolomite sedimentary period may be an open platform in the Yangtze area, The δ13C value of dolomite may inherit the carbon isotopic characteristics of mantle source CO2. There is no significant difference in the δ13C values of carbonates in deep-water and shallow-water areas. (2) The sediments of Lower Doushantuo Formation 2 and Doushantuo Formation 3 The δ13C value of the deep-water area is significantly lower than that of the shallow water area, and the δ13C value of the deep-water area is not significantly different from that of the Doushantuo Formation and the δ13C value of the shallow water area is significantly increased. 3) The δ13C values of the Doushantuo basin during the depositional stage of the 4th member of Tuoji Formation decreased significantly, and the δ13C values in different depositional environments decreased. The marine stage evolution of Ediacaran Jiu Doushan Tuo after the cap is mainly related to the gradual oxidation of the DOC reservoir in different periods of deep water.