Год издания: 1991

In the last 25 years, oil and gas pools have been discovered in Upper Proterozoic deposits aged 1000 to 570 million years, initially in the regions of the Siberian platform in the U.S.S.R. and then in China and Oman. The most important results were obtained in the Siberian platform, where more than 30 fields have been discovered, including a number of giant ones. Oil shows in Precambrian deposits have been detected in the East European, North American and Australian platforms. The most ancient source rock formations (1400 to 1600 million years) and oil shows have been recognized in the McArthur basin in Australia. Oil geochemistry on Precambrian source rocks shows that their composition is similar to that of black shale bitumoids and associated Phanerozoic oils, suggesting the unity of living matter biochemistry at least over 1600 million years. Some features of the most ancient oil composition have been detected. The authors estimate the amount of unmetamorphosed sedimentary rocks at 39000 km2. 95 to 150 billion tonnes of in situ resources of oil and 35 to 70 trillion m3 of gas are predicted to be in them. The Precambrian deposits of ancient platforms will be a new prospective stratigraphic level for oil and gas exploration during the next decades. The idea that oil potential declines with increase of sedimentary rock age, which is widely accepted by geologists, has not been substantiated.