Abstract

The Neoproterozoic Kaoko belt of northwestern Namibia, to the west of the Congo craton, consists of basement gneisses and a sequence of highly deformed metasedimentary and metavolcanic rocks. The metasedimentary rocks are interpreted as the infill of a narrow north-trending basin floored by attenuated continental crust. Similar basins are represented by the western continuation of the Kaoko belt—the Dom Feliciano and Ribeira belts of eastern Brazil. On the basis of consideration of data from these belts, the Kaoko belt rocks indicate the absence of a large Neoproterozoic oceanic basin between the Congo and southwestern American cratons. Deformation structures in the Kaoko belt show transpressional kinematics with strain partitioning at around 550 Ma. North-northwest–south-southeast, sinistral transcurrent shear in the west passes eastward into east-southeast–directed thrusting. The transcurrent shear component dominates temporally and in strain intensity. Dextral transcurrent motion at 550 Ma is recorded in the east-northeast–trending Schlesien-Mwembeshi shear zone, bordering the Congo craton to the south. Accordingly, the Congo craton extruded northeastward along the Kaoko belt and the Schlesien-Mwembeshi shear zone relative to the Kalahari craton in the southeast and the South American cratons to the west. This extrusion probably resulted from a final phase of convergence between east and west proto-Gondwana.

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