Neoproterozoic Petroleum Systems of Central-West Africa

Proven Neoproterozoic petroleum systems are present in China, Oman, Russia, and Brazil, here they occur in Tonian (1000-850 Ma), Cryogenian (850-635 Ma) and Ediacaran (635-540 Ma) strata. Discoveries in these areas provide momentum for exploration in Precambrian strata of central-west Africa where research is underway. In many basins where there is a proven or potential hydrocarbon presence, deposits of the “Sturtian” and the “Marinoan” Cryogenian “snowball Earth”-style glaciations occur.

To understand the Neoproterozoic petroleum systems of central-west Africa, a collaborative research program is underway between the Royal Holloway University of London and the Royal Museum for Central Africa (MRAC, Belgium), the University of Namibia and the University of Zambia. The study area straddles the West Congo Belt, the Lufilian Belt (DRC, Zambia) and the Otavi Mountains (northern Namibia). In the Rodinia supercontinent configuration, the area was coterminous to the São Francisco Basin (Brazil), which contains a functioning petroleum system; this basin can be used as an analogue to the African counterpart of the Congo-São Francisco craton.

In the Lufilian and West Congo Belts, comparatively little is known about the stratigraphy of Neoproterozoic carbonates and/or diamictites. The majority of previous research has been conducted prior to 1980, before the development of modern concepts of carbonate ramp architecture. Fieldwork is thus being undertaken to improve this understanding, complemented with rock sample analyses and interrogation of MRAC archives. Stratigraphic correlation is aided with portable gamma-ray spectrometry at outcrops, which also aids recognition of potential source rock intervals. In this paper, we present data from northern Namibia and from the mines of the Copperbelt district of Zambia. Thick successions of Neoproterozoic carbonates are the best potential reservoirs and some also have source rock potential (“fetid” dolomites, stromatolites / microbialites).

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California