The Association of Hydrocarbon with Basement Rock of Pre-Phanerozoic Age

Abstract

Until recently, the occurrence of oil and gas in rock of pre-Phanerozoic age was considered of insignificant importance, as demonstrated by published reports and the supposed lack of hydrocarbon source and reservoir rock of Precambrian age. Discoveries since 1956 of economic hydrocarbon deposits associated with Precambrian basement rocks have led to worldwide exploration for similar resources. Known associations of gas and oil with ancient basement rocks can be classified as either ascendant, descendant, or indigenous. The principal geology of economic hydrocarbon discoveries pertaining to each of these classifications is presented in this paper.