NEOPROTEROZOIC EVENTS IN THE TCHOLLIRE AREA - PAN-AFRICAN CRUSTAL GROWTH AND GEODYNAMICS IN CENTRAL-NORTHERN CAMEROON (ADAMAWA AND NORTH PROVINCES)

The Rei Bouba Group is a sedimentary and volcanic sequence (750-?650 M a), regarded as a remnant of a Pan-African (back-are?) orogenic basin that separated a remobilized Paleoproterozoic crust from an accretiona ry area (Poll Complex: 800-650 Ma). The latter was subjected to early deformation (D1) and intruded by calc-alkalic plutons (670 Ma). Transp ressive tectonics and major thrusting, with emplacement of synkinemati c granite, occurred at cn 630 Ma (D2-3) and a late compression (D4), w ith emplacement of calc-alkalic granite, occurred at ar 570 Ma. The Tc hollire Shear Zone is regarded as part of the major boundary between a recently accreted crust and the remobilized margin of the Congo Crato n.