The regularities of formation of the porosity of Vendian-Cambrian terrigenous deposits in the southern Siberian Platform (from data of complex petrophysical research)

We have studied the main factors that affect the consolidation of terrigenous rocks. The porosity of mudstones of the Nepa Formation (Siberian Platform) is shown to reflect the maximum pressures under which the rocks existed throughout their geologic history. Thus, it can be used for regional paleotectonic analysis. At the same time, the porosity of sandstones depends on much more factors exerting their effect during sedimentation as well as during subsequent catagenesis of the rock. Most of them are depths of maximum burial of sediments, size of mineral grains, and intensity and time of secondary cementation of rocks.