About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Special Volumes



Copyright copy2012 by The American Association of Petroleum Geologists.

Cross-regional Intraslope Lineaments on the Lower Congo Basin Slope, Offshore Angola (West Africa): Implications for Tectonics and Petroleum Systems at Passive Continental Margins

Dengliang Gao,1 Jeff Milliken2

1Department of Geology and Geography, West Virginia University, 98 Beechurst Ave., Morgantown, West Virginia, 26506, U.S.A. (e-mail: [email protected])
2Marathon Oil Corporation, Houston, 5555 San Felipe St., Texas, 77056, U.S.A. (e-mail: [email protected])


A part of this chapter was presented at the 2007 Gulf Coast Associate of Geologic Societies (GCAGS) annual conference. We thank Marathon Oil Corporation for permission to publish the chapter. Marathon technology services generated 3-D depth-migrated data used in this study. Paradigm Geophysical Inc., and Midland Valley Inc., provided software for 3-D and two-dimensional (2-D) structure modeling. We also thank Shankar Mitra, Dozith Abeinomugisha, and Maria Jose R. Oliveira for their peer reviews. Colin P. North served as the guest editor for this chapter, and Suzanne Beglinger and Mike Sweet provided additional peer reviews that helped to further improve the quality of the chapter. This chapter is a contribution to the West Virginia University Advanced Energy Initiatives program.


Approximately 20,000 km2 (7900 mi2) of three-dimensional (3-D) seismic data, along with the Bouguer gravity and bathymetry, show a series of intraslope lineaments that extend more than tens of kilometers (miles) in the Lower Congo Basin, offshore Angola (west Africa). Most of these lineaments trend to the northeast at approximately 45deg, crossing the regional northwest-trending folds and thrusts. Geometric relationships and distribution patterns of folds and faults shown in the postsalt Tertiary section suggest that many of the lineaments might have a significant strike-slip component. Seismic structures, facies, and prospects indicate that the lineaments have been associated with the allochthonous salt bodies, turbidite sands, and oil and gas fields. We interpret that the lineaments are primarily related to the postsalt regional gravitational sliding of the Tertiary sediments. They could provide fairways for turbidite flow and pathways for salt emplacement and hydrocarbon migration. We infer that many cross-regional lineaments are the expression of the presalt basement transfer faults formed during the rifting phase of the continental crust in the Early Cretaceous have influenced the locus and orientation of the lineaments in the postsalt sediments. The obliquity of the continental lineaments (45deg) to the oceanic fracture zones (80deg) is consistent with and supportive of the previously recognized plate tectonic model depicting the counterclockwise rotation of the west African continent associated with the southward opening of the South Atlantic Ocean. These findings provide important insights to the nature of the cross-regional lineaments and their implications for tectonics, sedimentation, and petroleum systems at the west African passive continental margin.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24