Structural tectonic evolution of the Buffels river shear zone, Namaqua sector, Namaqua-natal metamorphic province, South Africa
Abstract
The Buffels River shear zone is located in north-western Namaqualand within the
Bushmanland Subprovince, approximately 50 km south of the town of Springbok in the
Namaqua Metamorphic Province in South Africa. The Buffels River shear zone has an overall
ENE-WSW orientation and spans approximately 95 kilometres from the West Coast belt to the
Bushmanland plateau in the east where it is further masked by Cenozoic cover. The trace of
the supracrustal belt is defined by a steep NNW-dipping, 4 km-wide zone consisting of mainly
sheared supracrustal sequences and streaky augen gneiss which have a regionally consistent
ENE-WSW trend of about 260°. The rocks of the supracrustal belt occur as sheet-like bodies
generally concordant to the regional gneissic foliation and are bordered on either side by a wallrock
of less deformed coarse-grained augen gneiss which has the same penetrative foliation
trend as the supracrustal belt.