The East African margin and SW Indian Ocean represents a rift-drift part of Gondwana. Compared to the West African margin, this part of Gondwana is relatively less studied and explored in terms of its hydrocarbon prospectivity; moreover, this region has undergone a more complex tectonic evolution with multiple rift-drift events since the Permian, which offers attractive opportunities for hydrocarbon exploration, but also poses a formidable challenge to construct the history of basin formation, fill and deformation.
Given the significance of the region for further exploration and the need for a regional synthesis and presentation of data on an ArcGIS platform, this research work was conducted as an industry consortium during 2011–2012.
This study involved systematic data mining, quality check, coherent synthesis and interpretation of data relevant to regional geology, stratigraphy (litho-, bio-, chrono- and stratigraphy), basin structure, and paleofacies evolution together with relevant information on petroleum systems and plays of the various basins and sub-basins.
Scope of Work
Research covers the East African Margin from Somalia through Ethiopia, Kenya and Tanzania to Mozambique (both onshore and offshore), Madagascar onshore and offshore, and Seychelles platform. The East African margin and SW Indian Ocean basins evolved from the rift-drift tectonics of Gondwana. The study region has been divided into 24 Mesozoic-Cenozoic sedimentary basins. The intervening oceanic basins (Somali, Mozambique Channel, and Mascarene) were also covered incorporating data from DSDP-ODP drilling and seismic data.
The final report provides a rapid assessment tool on tectonostratigraphy, paleofacies evolution, and petroleum plays of the East African Margin, Madagascar and Seychelles. Systematic data mining, quality check, coherent synthesis and interpretation of data relevant to regional geology, stratigraphy (litho-, bio-, chrono- and stratigraphy), basin structure, and paleofacies evolution together with relevant information on petroleum systems and plays of the various basins and sub-basins are integrated to produce the primary deliverables.
- Regional maps including surface geology, bathymetry, structures, gravity, on ArcGIS
- Integrated chrono-litho-tectonostratigraphic charts (with information on relevant petroleum plays)
- Biostratigraphic charts for distribution of microfossils from wells and outcrops available in the literature
- Structural transects onshore to deepwater for various basins (as data permitted)
- Regional paleogeographic maps from the Permian through the Pleistocene with a focus on intervals of major tectonic events and deposition of source or reservoir rocks
- Geochronology of igneous activities. Given the multiple igneous events related to continental rifting, plume activity and ocean-floor spreading and the implications of these events on rift basin formation and thermal history of the basins, we synthesized the geochronology data of the igneous activities in the study region and reviewed the data in terms of the tectonic and basin evolution
- Spreadsheets for well data as available in the literature and used for the project
- Collected the available data on source and reservoir rocks
- Bibliographic database for various basins
ArcGIS 9.2 serves as the platform for the project deliverables. An overview of the scope and findings of the research can be seen on the project summary.
Paleofacies maps for 19 stratigraphic horizons covering the Late Carboniferous-Pliocene, and recognition of 6 megasequences through tectonostratigraphic correlation of the basins shed light on potential hydrocarbon plays in the region, some already well explored, while others bypassed or little investigated.
Four major tectonostratigraphic events in the study region are examined and described in the full Report. A detailed overview is is available in the Project Summary PDF.
The Project Report provides a rapid assessment tool on tectonostratigraphy, paleofacies evolution, and petroleum plays of the East African Margin, Madagascar and Seychelles.