SHRIMP U-Pb zircon geochronology of granites from the Central Zone, Limpopo Belt, southern Africa: Implications for the age of the Limpopo Orogeny

This paper presents new U-Pb (SHRIMP) data for zircons from syn- and post-tectonic granites in the western part of the Central Zone, Limpopo Belt, southern Africa. These data are used to assess constraints on the timing of collisional orogeny in the: Central Zone. The Selebi-Pikwe and Makowe Hills granites are Late Archaean in age. Field and fabric relationships indicate that these syntectonic granites intruded during the Limpopo Orogeny, thereby providing a minimum age constraint on the contractional stage of orogenesis. This interpretation suggests that recently published mineral ages of c. 2.0 Ga from the eastern part of the Central Zone date metamorphism during reworking of Archaean age shear zones, rather than collision between the Kaapvaal and Zimbabwe Cratons. The Mahalapye granite in the extreme western part of the Central Zone is a post-tectonic intrusion that crystallized at 2023 +/- 7 Ma. The granite is unconformably overlain by rocks of the Palapye Group for which it provides a maximum age.