Unravelling the along-strike variability of the Angola–Gabon rifted margin: a mapping approach
Gwenn Péron-Pinvidic, Gianreto Manatschal, Emmanuel Masini, Emilie Sutra, Jean Marie Flament, Isabelle Haupert, Patrick Unternehr, 2017. "Unravelling the along-strike variability of the Angola–Gabon rifted margin: a mapping approach", Petroleum Geoscience of the West Africa Margin, T. Sabato Ceraldi, R. A. Hodgkinson, G. Backe
Download citation file:
We summarize here observations from the South Atlantic Angola–Gabon rifted margin. Our study was based on the interpretation of a selection of deep penetration depth-migrated seismic reflection profiles. We describe here the large-scale dip architecture of the margin under five structural domains (proximal, necking, distal, outer and oceanic) and list their characteristics. We investigated the necking domain further and discuss the architecture of the distal domain as a combination of hyper-extended crust and possible exhumed mantle. The mapping and characterization of these domains, at the margin-scale, allow us to illustrate the along-strike structural and stratigraphic variability of the margin. We interpret this variability as the result of a shift from an upper plate setting to a lower plate setting. This shift is either sharp, typified by a major regional normal fault on the northern flank of a residual hanging-wall block, identified offshore Cabinda–Zaire, or more diffuse to the south. First-order screening of conjugate profiles confirmed the segmentation and structural characteristics of the transfer zones. The dataset studied also allowed the identification of key sections that can be considered as type examples of upper plate and lower plate margins and which allow us to discuss the characteristics of these end-member settings.
Figures & Tables
The West Africa margin, formed by the progressive separation of the South American and African continents, has enjoyed a rich and varied exploration history and become a significant hydrocarbon-producing region. The amalgamation of hydrocarbon exploration approaches and imaginative ideas, leveraged with modern technologies, is yielding significant scientific and economic successes within the region.
The main objective of this Special Publication is to provide an overview of the advancement in understanding of the crustal structure, tectonic evolution and Mesozoic to Cenozoic stratigraphy of the West Africa margin both onshore and offshore, with a particular focus on the petroleum geology.