|
Limpopo Belt |
  
|
|
Limpopo Belt |
|
Introduction The 250 km wide Limpopo belt of southern Africa is an east-northeast trending zone of granulite facies tectonites separating the granitoid-greenstone terranes of the Kaapvaal and Zimbabwe cratons. Large scale ductile shear zones are an integral part of Limpopo belt architecture. They define the boundaries between the belt and the adjacent cratons and separate internal zones within the belt. The shear zones forming the external (northern, southern and western) margins of the belt are interpreted as uplift structures of the overthickened crust. The crustal evolution of the Limpopo Central Zone can be summarized into three main periods: 3.2-2.9 Ga, ~2.6 Ga, and ~2.0 Ga. The two first periods are mainly characterized by magmatic activity leading to the formation of Archaean Tonalite-Trondhjemite-Granodiorite (TTG) such as the Sand River Gneisses or the Bulai Granite intrusion. The Early Proterozoic event took place under high-grade metamorphic conditions during which partial melting formed large amount of granitic melt. The Limpopo Central Zone shows relics of late Archean high grade metamorphism. In the Northern (NMZ) and Southern Marginal Zones (SMZ) that adjoin the Zimbabwe and Kaapvaal cratons, respectively, the last high grade metamorphic episodes were late Archean. Geohydrology No information
Source: http://www.kruger2canyons.com |
