Carbon and oxygen isotopic composition of the Vendian-Cambrian carbonate rocks and paleoecological reconstructions

The carbon isotopic composition of carbonate rocks is widely used for the reconstruction of sedimentation paleoenvironment. Of special interest is the study of the Upper Proterozoic-Cambrian interval—the turning point in the Earth’s geological evolution. Rocks of this age show the widest variations in the carbon isotopic composition of carbonates typically correlated with epochs of global glaciations and change in the CO 2 regime. In this paper, we attempted to show that carbon isotopic variations often indicate postsedimentary alterations of carbonates and reflect the specific geochemical transformations of the rocks. Study of variations of carbon and oxygen isotopic compositions in the Vendian-Cambrian rocks provide insight into lithogenetic processes.