Global Neoproterozoic Petroleum Systems - Snowballs, Source Rocks and the search for “Old Oil” in North Africa and Middle East

Abstract

The Neoproterozoic eon, stretching from 1000 Ma to the base of the Cambrian at 542 Ma, is relatively poorly known from a petroleum perspective despite the existence of proven plays in many parts of the world including Oman, Mauritania, Siberia, India, Pakistan, Australia and the United States. Many of the proven “Infracambrian” (Neoproterozoic to Early Cambrian) hydrocarbon plays around the world depend on the presence of prolific “Infracambrian” source rocks. There is increasing evidence that deposition of many of these organic-rich units was triggered by strong post-glacial sea level rises, on a global scale, following the “Snowball Earth” type glaciations, coupled, in some areas at least, with basin development and rifting on a more local scale. Neoproterozoic to Early Cambrian organic-rich strata were deposited in both high latitudes (e.g. Mauritania) and low latitudes (e.g. Oman) along the North Gondwana Margin. Some of the black shales encountered on the West African Craton may be as old as 1000 Ma and clearly predate the Pan-African orogenic event. These are substantially older than the majority of the Infracambrian organic-rich units that occur across much of North Africa and the Middle East (including those in Oman) which predominantly range from c. 850 - c. 540 Ma in age.