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Contrasting modes of rifting: The Benue Trough and Cameroon Volcanic Line, West Africa
Author(s) -
Okereke C. S.
Publication year - 1988
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/tc007i004p00775
Subject(s) - geology , rift , trough (economics) , cretaceous , lithosphere , bouguer anomaly , volcano , east african rift , seismology , paleontology , rift valley , tectonics , gravity anomaly , oil field , economics , macroeconomics
The Benue trough of west Africa is commonly believed to be a rift feature that originated in the Cretaceous at about the time that Africa and South America began to separate. Bouguer gravity and available geological data in the trough indicate that its formation was probably the result of regional horizontal stresses in the lithosphere, causing crustal extension and surface subsidence. By contrast, the data for the adjoining Cameroon volcanic line suggests that the associated tensional stresses relate to mantle upwarp causing thinning of the lithosphere and regional crustal uplift similar to that associated with the Kenya rift. Thus the association of passive and active rifts seen in the Afro‐Arabia rift system is also a feature of the Cretaceous rift system in west Africa.