Trans-Saharan seaway connection between the South Atlantic and the Tethys Sea during the Coniacian–Turonian: Evidence from bibliographical synthesis, field mapping, and seismic interpretation

Abstract

This paper presents an up-to-date review of Nigerian geological evolution during the Upper Cretaceous to treat with in-depth knowledge gathered from previous literature, field geological mapping and 2D seismic interpretation, the contentions concerning possible pathways of entrance throughout transgressive episodes that guide the initiation of the Trans-Saharan seaway. Assessment of the economic potency of this portion, inclusive of the petroleum system and coal (fossil fuel) deposits, groundwater, and mineral resources. Two episodes of transgression connected large number of Upper Cretaceous basins of Nigeria. The first Trans-Saharan seaway between the South Atlantic and the Tethys was confirmed during the Turonian time and started flooding southwards from the Cenomanian, of which the first transgression was entrenched in the Bida and Yola Sub-basins. The connection pathway was probably east and westward, linking Tethys with the Gulf of Guinea along the Benue Trough and Bida Basin. These resulted in extensive marginal marine conditions in the Campanian-Maastrichtian favored the deposition of coal, ironstone, and clay of great economic value. This connection was put to a standstill by the Santonian epeirogenic event (inversion, reversal, etc.) made distinctive by folding, faulting, uplift, and intrusions. A second transgression, beginning in the Campanian to Maastrichtian, re-confirmed the Trans-Saharan seaway through a westward Bida Basin path in the Maastrichtian, coming to a climax globally. Mainly marginal marine environments in Benin, Anambra, Sokoto, and Bida basins as established in this paper. The inundation of oceanic waters from the Tethys, restricted in expanse by the edified region of the southern Benue Trough brought about marginal marine conditions in the northern, central Benue Trough, and Chad Basin. Extensive deposition of clay, coal, ironstone. Also, good to prolific aquiferous units occurred during this time.