The Grenvillian Namaqua fold belt adjacent to the western Kaapvaal Craton: 2. Archaean Craton and supercontinent connections

Namaqua crust was thickened (20-25 km) by both structural stacking and sheeted intrusions (Namaqua tectogenesis) with clockwise PTt-paths in the west-central Namaqua sector (Olifantshoek, Grünau, Pofadder, Bladgrond Terranes). In the western part (Okiep/Garies Terrane), crust was dominantly thickened by massive sheetlike granitoid intrusions resulting in granulite grade and anti-clockwise PTt-paths. COLKAD-rooted inter/intra-terrane thrusts are subhorizontal except where rotated by subvertical (discrete) shear zones (e.g. Tantalite Valley and Brakbos-Doringberg-Dabep). Crustal thickening and granulite-uplift stimulated temperature rise with anatexis-palingenesis of early Columbian/supracrustal rocks. Kilometer-scale granitoid bodies, derived from predominantly Columbian crust (according to isotopic source rock models) that are emplaced along shear zones, caused a rise in the brittle to ductile transition zone (i.e. mid-crustal conditions) and low-pressure granulite facies.