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.

Published whole-rock Sm-Nd and zircon Lu-Hf data from the Limpopo Complex and adjoining areas of the Zimbabwe and Kaapvaal Cratons provide insight into the regional crustal evolution and tectonic processes that shaped the complex. The Northern Marginal Zone of the complex, and the Francistown area of the Zimbabwe craton, represent an accretionary margin (active at 2.6–2.7 Ga) at the southern edge of that craton, at deep and shallow crustal levels, respectively. The Southern Marginal Zone represents a deep crustal level of the northern Kaapvaal Craton and was not an accretionary margin at the time of high-grade metamorphism (2.72–2.65 Ga). The syntectonic Matok granite was produced by crustal anatexis. In the Central Zone, the presence of ca. 3.5–3.3 Ga crust is indicated throughout its E-W extent by T Nd,DM model ages of metapelites and by zircon xenocrysts and their T Hf,DM model ages. The ca. 2.65 Ga granitoids in the Central Zone (the Singelele-type quartzofeldspathic gneisses in the Musina area, granitoids in the Phikwe Complex, Botswana, the so-called gray gneisses, and the Bulai charnockite) were formed by anatexis of such old crust, whereas 2.6 Ga juvenile (arc-related?) magmatism produced the Bulai enderbite, and may be a component in the Zanzibar gneiss. The Mahalapye granitoid complex in Botswana was formed by crustal anatexis at 2.0 Ga, but mafic and hybrid rocks of this age have a mantle-derived component. The data do not prohibit a collisional model for the Neoarchean high-grade metamorphic event in the Central Zone and Southern Marginal Zone of the Limpopo Complex.