Kwanza

Potential Source-Rocks

Transgressive Phase of the Continental Encroachment Cycle

In the conventional offshore, the condensed stratigraphic section associated with the major Meso-Cenozoic downlap surface (boundary between the transgressive and regressive phase of the post-Pangea continental encroachment cycle) is, often, an alternative generating petroleum sub-system to the Albian marine source rocks. The organic matter of this interval, which in tentative interpretation of a Canvas autotrace corresponds to the interface between the intervals colored in light blue and dark blue (Cenomanian-Turonian) is, often, immature in the proximal part of the offshore. However, in the more distal parts of the basin, the burial is, generally, sufficient for the organic matter of such a potential source rocks reach the oil window. As illustrated, the size of the rift-type basins is too small to prevent a lateral sand filling, i.e., to allow the development of a lake, in which organic matter can be originated and, later, preserved (lacustrine source-rocks). On the other hand, the seismic data of this area do not show, in the Atlantic-type margin (above the breakup unconformity), any infra-salt depocenter, as it is the case in other areas of the Angola offshore.

To see a more distal seismic line (autotrace) click here