Discovery and geological significance of high quality hydrocarbon source rocks in interglacial of Neoproterozoic in the eastern part of the southern margin of North China

Abstract

A conglomerate of glacial deposits from Neoproterozoic Sinian is generally developed in the southern margin of the North China Plate. However, whether the hydrocarbon source rock exists in a conglomerate of glacial deposits is still undeterminable as it has not been studied previously. The developmental characteristics of the conglomerate were systematically observed and measured. The conglomerate was subsequently divided into four sets, and the gray-black shale was discovered in between them. The said shale has the thickness of 36 m, 46 m, and 7 m, respectively from top to bottom. The study presents the highly-abundant organic matter in the shale, which belong to the high-quality hydrocarbon source rock. The organic matters are derived from lower organisms. The discovery of thick and high-quality hydrocarbon source rocks in conglomerates opens up new exploration areas for conventional natural gas, as well as provides a powerful basis for shale gas exploration. The dropstones that appeared in hydrocarbon source rocks and conglomerates are cogent evidence of glaciation. The findings provide an important guiding significance for the genesis of the conglomerate. Keywords: Southern margin of North China plate, Neoproterozoic, Moraine conglomerate, Hydrocarbon source rocks, Significance