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-t ectonic granites in the western part of the Central Zone, Limpopo Belt, sou thern Africa. These data are used to assess constraints on the timing of co llisional orogeny in the: Central Zone. The Selebi-Pikwe and Makowe Hills g ranites are Late Archaean in age. Field and fabric relationships indicate t hat these syntectonic granites intruded during the Limpopo Orogeny, thereby providing a minimum age constraint on the contractional stage of orogenesi s. This interpretation suggests that recently published mineral ages of c. 2.0 Ga from the eastern part of the Central Zone date metamorphism during r eworking of Archaean age shear zones, rather than collision between the Kaa pvaal and Zimbabwe Cratons. The Mahalapye granite in the extreme western pa rt of the Central Zone is a post-tectonic intrusion that crystallized at 20 23 +/- 7 Ma. The granite is unconformably overlain by rocks of the Palapye Group for which it provides a maximum age.