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Stratigraphic Evolution of the Benue Trough and Its Implications for the Upper Cretaceous Paleogeography of West Africa

1978; University of Chicago Press; Volume: 86; Issue: 3 Linguagem: Inglês

10.1086/649693

1537-5269

Sunday W. Petters,

Geological formations and processes

The main stages of tectonic evolution of the Benue Trough are well documented in the stratigraphic succession, basically comprising three depositional sequences: an Albian-Cenomanian pyroclastic, paralic, shallow marine, and fluviatile sequence corresponding to the graben and transitional tectonic stages; a Turonian-Coniacian paralic, marine and fluviatile sequence that resulted from downwarping and a consequent widespread marine transgression; and a Campanian-Maastrichtian paralic, marine and fluviatile offlap sequence which followed the Santonian compressional deformation episode that displaced the depositional axis westward. Sedimentation in the trough was strongly influenced by the Late Cretaceous eustatic rise of sea level. The paleogeography of the Benue Trough in the Late Albian was similar to that of the Gulf of Tajura of the Afar triple junction. Thus, the equatorial and South Atlantic Oceans were open at that time and an embayment projected into the Benue Trough. Paleobiogeographic evidence and regional facies distribution in the Sahara and northeast Benue Trough do not support an open connection between the Late Cretaceous Saharan sea and the Benue Trough.