Tectonic evolution of the southern Kaoko belt, Namibia

Abstract The tectonic evolution at the junction of the Panafrican Kaoko and Damara belts is well recorded in the siliciclastic and carbonate successions of the Neoproterozoic Zerrissene turbidite system, metamorphosed to the biotite zone of the greenschist facies. The structures in the turbidites are attributed to two main deformational events. The older one generated two continuous folding phases, D1 and D2, and the younger one resulted in D3 deformation. D1, of dominant E–W shortening, caused upright kilometre-scale folds with well-developed axial planar cleavage, N–S trending axial planes and subhorizontal axes. This phase graded into D2 that refolded the first folds coaxialy and developed a crenulation cleavage at a high angle to the first cleavage. D2 is interpreted as a phase associated with shear movement to the north and minor continuing E–W shortening. The third phase, D3, of apparently sinistral transpression caused localised fold trains on a metre to kilometre scale with NE to NNE trending subvertical axial planes. The first two phases predate intrusion of a 530 Ma syenite and probably correlate with the main deformation in both the Kaoko and Damara belts. D2 is likely coeval with motion of the sinistral strike-slip Purros lineament in the central part of the Kaoko belt. D3 postdates the syenite intrusion and is restricted in occurrence to the Damara and southern Kaoko belts. Deformation in the Damara belt therefore outlasted that in the central and northern parts of the Kaoko belt.