Abstract:

The Termit Basin and its adjacent areas are the typical MesozoicCenozoic rift basin of West African Rift System (WARS), and they are also the most potential risk exploration area for CNPC overseas. However, because of the complex tectonic movement, the study area is lack of system analysis in paleogeographic evolution of the Upper Cretaceous. In this article, we take the Termit Basin and its adjacent areas as our study area. On the basis of tectonic evolution, we comprehensively utilize geochemistry, stratigraphy and geophysics to analyze the paleosedimentary environment and Paleogene provenance in the study area. The study suggested that during the early Cenomanian in the study area the transgression began to occur, and it achieved maximum transgression in the Santonian, then the sea level began to descend. Because of the regional tectonics, the uplifting movements occurred in the Termit Basin and the west part. The geochemical, lithological and seismic data show that the Termit Basin and its adjacent areas were in shallow shelf deposition during the CenomanianSantonian period, and the provenance mainly came from the NE direction; during the second period, the sedimentary facies of marine deposit transited to transitional facies, and the provenance came from the NE and SW directions; and all of this had provided the theoretical basis for the analysis of sedimentary systems and sand body prediction.

Key words: tectonic evolution, sedimentary environment, palaeogeographic evolution, Upper Cretaceous, Termit Basin, West and Central Rift System