Petro-Structural Characterizations of the Hypovolcanic Formations of the Pan-African Basement and the Cretaceous Sedimentary Basins of Figuil (North Cameroon) and Léré (South-West Chad): Geodynamic Implication of the Pan-African Range of Central Afri

The localities of Figuil (Northern Cameroon) and Lr (Southwest Chad) belong to the northern domain of the Pan-African Range of Central Africa (CPAC).Field observations and petrographic and structural studies have revealed the existence of two categories of dolerites depending on the nature of the surrounding rock: (1) dolerites of the Pan-African base (DSP) made up of dolerites with pyrite and calcite , dolerites with pyrite and basement enclaves, dolerites with amphibole and titanite and dolerites with pyrite and dolerites from the Cretaceous sedimentary basins (DBSC) composed of amphibole dolerites, biotite and pyroxene dolerites, pyroxene dolerites, gabbros with fine grain and trachytes.The textures of these rocks are intergranular to granophyre, doleritic, sub-ophitic, ophitic to granophyre, ophitic and subdoleritic.The installation of these magmatic rocks is probably linked to major accidents in the study area in NNW-SSE, NE-SW, E-W and ESE-WNW directions, similar to those of the Pan-African faults which would be close to the direction affecting the base of the Pan-African Chain of Central Africa (CPAC).