Congo

Potential Source-Rocks

Transgressive Phase of the Continental Encroachment Cycle

In the Congo offshore (north of Angola), the major downlap surface between the transgressive and regressive stratigraphic phases of the post-Pangea continental encroachment cycle is indicated on this Canvas autotrace by the continuous red/white marker. Locally, its burial exceeds 3 seconds (t.w.t.), which is sufficient for the organic matter of the associated potential source-rocks deposited during the Cretaceous marine ingression to reach maturity. On this tentative geological interpretation, if there are rift-type basins, with lacustrine source-rocks, they are included in the infrastructure of the Atlantic-type divergent margin (infra-salt strata), which can comprise, also, infra-salt margin sediments, SDRs (post- breakup lava flows), oceanic crust and basement Probably, in this area of the Angola offshore, the principal generated petroleum sub-system is located between the Cenomanian/Turonian downlap surface and the top of the salt interval (colored in violet), i.e., in the transgressive phase of the post-Pangea continental encroachment cycle. The presence of a dispersive Cenozoic generating petroleum sub-system cannot be exclude in the regressive phase of the continental cycle.