The results of 50 years of geochronological work in the Limpopo Complex are reviewed. The data define three main age clusters. The oldest, at ca. 3.3 Ga, exists in the Central and Southern Marginal Zones and is defined by magmatic zircon dates. The second, with a genuine spread between 2.7 and 2.55 Ga, occurs in all three zones. It was a period of high-grade regional metamorphism with intense deformation and widespread anatexis, dated also mainly (but not exclusively) by zircon U-Pb. The third cluster is well constrained at 2.02 ± 0.02 Ga in the Central Zone by zircon overgrowths, sparse magmatic zircons, monazite, apatite, Sm-Nd and Lu-Hf garnet dating, Pb/Pb discrete phase and stepwise leaching dating of garnet and titanite, and hornblende Ar/Ar dating. The Paleoproterozoic dates from metamorphic minerals are particularly associated with zones of intense transcurrent shearing at high-grade metamorphism. In the Northern Marginal Zone this event is more protracted, from 2.08 to 1.94 Ga, and defined in medium- to low-grade shear zones. In the Southern Marginal Zone it is absent. The evidence for both Neoarchean and Paleoproterozoic mineral ages, both defining high-grade tectono-metamorphic events, is in part paradoxical and has led to controversies as to the age of a proposed collisional orogeny. Studying the mineral dates in their tectonic context leads to the conclusion that fluid access in deformation, rather than mere reheating, mainly caused their partial resetting in the Paleoproterozoic event. This allows the controversy to be resolved.

We report new petrological data for granulites from the Central Zone of the Limpopo Complex, southern Africa, and construct a prograde P-T path that traverses from high-pressure granulite-facies metamorphism to peak ultrahigh-temperature (UHT) metamorphism by rapid decompression, which was followed by further decompression and cooling. Mg-rich ( X Mg ~0.58) staurolite enclosed within poikiloblastic garnet in an Mg-Al-rich rock from the Beit Bridge area is rarely mantled by a sapphirine + quartz corona, suggesting the progress of the prograde dehydration reaction: staurolite + garnet → sapphirine + quartz + H 2 O. The symplectic sapphirine + quartz developed around staurolite probably implies decompression from P >14 kbar toward the stability of sapphirine + quartz at T ~1000 °C along a clockwise P-T path. The orthopyroxene + sillimanite + quartz assemblage mantled by cordierite aggregates in a pelitic granulite from the same area also suggests extreme metamorphism and subsequent further decompression. Various corona textures such as kyanite + sapphirine, sapphirine + cordierite, and orthopyroxene + cordierite were probably formed as a result of decompression cooling events. The prograde high-pressure metamorphism and the following UHT event relate to the collisional tectonics of the Zimbabwe and Kaapvaal Cratons, which are associated with the amalgamation of microcontinents during the Neoarchean.