Regional paleogeographic evolution of west Africa: Implications for hydrocarbon exploration

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5802103

Hempton, M R; Rosen, M A; Coughlin, R M; Scardina, A D; Hagen, E S; Nordstrom, P J ^[1]

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1. Pecten International Co., Houston, TX (United States)

New paleogeographic reconstructions of west African continental margins provide a regional framework to contrast differences in hydrocarbon habitat and tectonostratigraphic style. Five regional provinces are delineated: (1) Northwest Africa margin from mauritania to Sierra Leone, (2) Transform margin from Liberia to Benin, (3) Niger delta of Nigeria, Cameroon, and Equatorial Guinea, (4) South Atlantic Salt basin margin from Cameroon to Angola, and (5) Southwest Africa margin of Namibia and South Africa. Computer-constrained paleogeographic reconstructions based on exploration data depict the separation of west Africa from South and North America during the Late Triassic to the present along three rift systems. In northwest Africa rifting began in the Late Triassic associated with the opening of the Central Atlantic. In southwest Africa rifting began between the southern tips of Africa and South America in the Early Cretaceous (Valanginian) and propagated northward to the Benue Trough, a broad zone of left-lateral shear and extensional basins that began to open in the Aptian. Between these two rift systems, the Transform margin rift system initiated in the Early Cretaceous (Barremain) as a wrench-fault dominated eastward extension of the Proto-Caribbean ocean that propagated to the Benue Trough by the middle Albian. The most important variables affecting the tectonostratigraphic and hydrocarbon evolution of the west African margins include (1) the geometry, kinematics, and duration of rifting; (2) distribution of rift basins relative to paleoclimate zones (which affects the deposition of lacustrine source rocks and evaporites while influencing the type and quantity of sediment derived from land); (3) sea-level fluctuations; and (4) distribution of deltaic and turbiditic depocenters.

• OSTI ID: 5802103
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
58 GEOSCIENCES
BENIN
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
CAMEROON
LIBERIA
MAURITANIA
NAMIBIA
EXPLORATION
NIGERIA
SIERRA LEONE
SOUTH AFRICA
GEOLOGIC HISTORY
GEOLOGIC MODELS
PLATE TECTONICS
RESOURCE POTENTIAL
RIFT ZONES
STRATIGRAPHY
AFRICA
DEVELOPED COUNTRIES
DEVELOPING COUNTRIES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
MINERAL RESOURCES
RESOURCES
TECTONICS
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration
580000 - Geosciences