The Bushmanland subprovince of the Namaqua Mobile Belt is characterised by HT/LP metamorphism around 1100 Ma over a 200- 300 km-wide zone with continuous N-S zoning from amphibolite to granulite facies terranes. The thermal peak of metamorphism is preceded by convergent tectonics with thrusting of previously thinned crust and major intrusions of synkinematic granitoids. While the granulite facies terrane shows an anticlockwise PT-path and isobaric cooling at a level corresponding to 5 kbar (Waters, 1990), the adjacent amphibolite facies zone is characterised by a clockwise PT-path. The PT-evolution may be generalised as follows: Pseudomorphs after andalusite in topazites indicate that the prograde path crossed its stability field. A further prograde relic is fibrolite that to some extent grew parallel to the stretching lineation of the major SW-directed thrust event. Fibrolitisation of feldspars, garnets, micas and spinel in contact with fibrolite indicate cation solution. It can be shown that this is an effect of prograde increase in temperature and pressure during continuous hydrous fluid flow. Relic inclusion phases in garnets of pelites and peraluminous rocks point to an equilibrium stage at 600°C/4 kbar after crustal stacking. Isobaric heating follows until the thermal maximum is reached at 680°C/4 kbar accompanied by anatexis. This is in contrast to the adjacent granulite terrane, where isobaric cooling follows the pressure peak. The early retrograde PT-path involves penetrative growth of coarse white mica and decompression of 1.5 kbar during cooling to 580°C. A late retrograde growth of low grade phases is caused by a penetrative infiltration of external fluids at 1.5 kbar/300-400°C. It is suggested that crustal stacking occurred in a warm thinned crust with basic magmatic underplating before and during convergence. The contrasting direction of the PT-paths of the amphibolite and the adjacent granulite terrane after reaching of the pressure maximum is interpreted as thermal relaxation towards a joint geotherm of about 45-50°C/km. This was the result of conductive heat transport after stacking of a crustal slice with an initially relatively lower geotherm over a slice with an initially relatively higher one. The convergence and related PT-evolution under elevated geotherms must have occurred in the inner part of a wide magmatic arc of a convergent Andean-type continental margin.