Mesoproterozoic intraplate magmatism in the Kalahari Craton: A review

Extensional and colisional magmatic records in the Apiaí Terrane, south-southeastern Brazil: integration of geochronological U-PB Zircon ages

“…This is also observed in once contiguous West Africa, such as the belts developed at the borders of the Congo Craton and south of the Kalahari Craton (Kaoko and Damara Belts: Tegtmeyer and Kröner, 1985;Chemale Jr. et al, 2003;Seth et al, 2005;Seth, Jung, Gruner, 2008;Kröner et al, 2004;Becker et al, 2006;Goscombe and Gray, 2007) , south of the Kalahari Craton (Hanson et al, 2004a(Hanson et al, , 2006, SE of the Congo Craton and the Central Africa-Kibaran Belts (Alonso and Theunissen, 1998;Kokonyangi et al, 2006), Kaapvaal Craton (Hanson et al, 2004b;Mapeo et al, 2004), W Anti-Atlas/Marocco (Gasquet et al, 2004), SE of the West Africa Craton (Caby, 2003) and Northern Zimbabwe Cráton (Oliver et al, 1998), Figure 1a.…”

The internal structure and geotectonic setting of the Xade and Tsetseng complexes in the western most part of the Kaapvaal Craton.

“…In this westernmost area the Umkondo magmatism is bimodal with felsic and mafic lavas and volcaniclastic sediments (Modie, 1996;Schwartz et al, 1996;Kampunzu et al, 2000;Singletary et al, 2003). This off-craton magmatism is interpreted as A-type, derived by partial melting of relatively juvenile crust (Kampunzu et al, 1998;Hanson et al, 2006). By contrast, the Xade and Tsetseng complexes are more typically wholly mafic which tends to confirm their cratonic setting.…”

“…Both the Xade and Tsetseng complexes are part of the Umkondo Igneous Complex or Large Igneous Province described by various authors (Hall et al, 2001;Bullen and Hall, 2002;Bullen et al, 2004;Singletary et al, 2003;Hanson et al, 2006). They have used geochemical, geochronological and palaeomagnetic data to identify widespread tholeiitic magma emplaced at ~1112-1106 Ma, over an area of about 2 x 10 6 km 2 , mostly across what is now southern Africa (Figure 1).…”

“…By contrast, the Xade and Tsetseng complexes are more typically wholly mafic which tends to confirm their cratonic setting. However, three distinct geochemical groups comprising calc-alkaline as well as more typical tholeiitic basaltic rocks have been identified from the Xade Complex (Bullen and Hall, 2002) and this is one line of evidence used to suggest that the Umkondo magmatism was caused by an upwelling mantle plume (Hanson et al, 2006).…”

“…Interpretations of primary airborne magnetic data indicate that this Complex is steeply dipping and may extend to considerable depths (Reeves, 1978;Meixner and Peart, 1984;Brett et al, 2000). A single borehole (CKP-8C) penetrated through overlying Kalahari beds and Karoo strata into 23m of deuterically altered, medium to coarse-grained gabbronorite and leucogabbronorite, locally with cumulate texture (Hanson et al, 2006). Samples from the core have yielded Rb-Sr and 40 Ar/ 39 Ar dates ranging from 1105±11 to 1021±86 Ma (Key and Mapeo, 1999;J.…”