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震旦 寒武交变期是地史上一个重大转折期 ,亦是一个具有特殊意义的过渡时期。运用碳同位素地球化学方法 ,探讨扬子地台北缘四川南江地区晚震旦世 早寒武世交变期 ,碳同位素地球化学异常与环境变化和生物演化的相互联系。南江剖面沉积岩有机碳同位素组成在 - 35 .8‰～ - 30 .1‰间变化 ;碳酸盐碳同位素组成从 - 3.5‰～ +0 .5‰。在灯影组顶部、牛蹄塘组下部和上部 ,变化的碳、硫同位素组成和不同的黄铁矿与有机碳含量反映了有机碳埋藏量和环境的变化。下寒武统富有机碳和黄铁矿的黑色页岩沉积 ,暗示了早寒武世早期缺氧环境的存在。
The Aurora Cambrian alternation period is a major turning point in the history of the earth and is also a transitional period of special significance. Using the carbon isotope geochemical method, we discuss the interdependence of the Late Sinian pre-Cambrian alteration, carbon isotope geochemical anomalies, environmental changes and biological evolution in the southern part of the Yangtze River in the southern part of the Yangtze River. The organic carbon isotopic compositions of the sedimentary rocks in the Nanjiang section varied from -35.8 ‰ to -30.1 ‰, while the carbon isotopic compositions of carbonates varied from 3.5 ‰ to +0.5 ‰. The changes of carbon and sulfur isotopic compositions and the different pyrite and organic carbon contents at the top and bottom of the Dengying Formation and the upper part of the Niutotang Formation reflect the changes in the amount of buried organic carbon and the environment. The black shale deposits of the Lower Cambrian organic carbon and pyrite suggest the existence of anoxic environments in the early Early Cambrian.