Formation Conditions of Hydrocarbon Deposits in Granite Massifs of the Provenozoic Basement of the Kyulong Basin (Vietnam)

Abstract

The problems of the origin of the hydrocarbon deposits located within the limits of the Protonozoic basement of the Vietnam shelf are considered. It is shown that the formation of hydrocarbon deposits is confined to the protrusive massifs of granites that underwent structural-tectonic processing at the stage of prototectonics and postmagmatic tectonics. The totality of postmultiplicative processes has led to a change in the viscosity properties of rocks, to their tectonic and material heterogeneity and stratification, and as a result to vertical and lateral redistribution in space with the formation of specific geostructures-granitic protrusions. Mechanisms of formation of a void space and traps of oil and gas within the limits of protrusions are considered. Based on the similarity of the geochemical characteristics and biomarker parameters of the oils and organic matter in the Oligocene-Miocene sediments of the cover and in the basement rocks, a conclusion has been made about the organic nature of the oils in the basement of the shelf of Vietnam.