Lithology and features of Vendian deposits formation in the south­eastern part of West-Siberian geosyneclise

In recent years on the territory of the South-Eastern part of West-Siberian geosyneclise the distribution of Vendian deposits was determined at significantly greater territory than it was considered before. In this regard, the study of the conditions of Vendian formations accumulation becomes relevant because of possible association of oil and gas deposits to them. The aim of the research is to study the peculiarities of lithological composition of deposits based on the study of the faunal remnants and fair determination of Vendian deposits existence, and to identify the features of distribution of certain lithological type of rocks by the area of their distribution using the method of paleogeographic reconstructions. As a result, and based on the earlier analysis of the tectonic structure of the South-Eastern part of West-Siberian geosyneclise the authors have determined the widespread propagation of sedimentary Dolomites and limestones of the Vendian period of pure carbonate without admixture of terrigenous material composition. They are traced not only within Vezdekhodny and Tiysky structural-facial areas, as it was known before, but on the territory of Nurolsky and obviously Kolpashevsky structural-facial areas as well. It allows making conclusion on the existence of carbonate platform on the vast territory with the center near the Vezdekhodnaya ground. Its deposits become potentially hydrocarbon bearing at wide development of secondary transformation. The corresponding complex of works could promote the discover of new oil and gas fields in the Precambrian carbonate rocks.