Facies analysis, hydrocarbon potential, palynology and geochemistry of Massoumbou sediments, Douala sub-basin, Central Africa

Abstract

Several analytical techniques including facies analysis, mineralogy, major and trace elements, palynology and Rock-Eval were used to reconstruct paleo-depositional environments, to determine the hydrocarbon potential and to propose the age of the deposits. The study is focused on a sedimentary outcrop in Massoumbou area, Eastern part of the Douala sub-basin (Central Africa). Lithologies mainly consist of claystones, siltstone and sandstones that were identified and grouped under seven facies. The mineralogical suite mainly comprises of quartz and kaolinite in association with pyrite, microcline, goethite and muscovite. Major and trace elements indicate intense weathering of the felsic and mafic sediment source rocks, and show that these sediments are immature to mature. Rock-Eval pyrolysis data indicate that most of the samples are thermally immature and are. organically rich in gas-prone kerogen Type III and IV. Morever, palynological data show palynofacies corresponding to gas prone. The organic matter consists of terrestrial components associated with organic matter of marine origin. Massoumbou deposits are poor to fairly rich in organic matter and have the potential to be a poor to good source rock liable to generate gas. Palynomorph species in occurence Retitricolpites simplex, Proxapertites spilatus, Momipites africanus, Kallosphaeridium yorubaense and the others one indicate Upper Paleocene age deposits in continental shallow marine environment. Some taxa such as Apectodinium spp. indicate climatic control during this period. This study reveals new data and the economic potential of this part of Central Africa.