SHRIMP U-Pb zircon ages of granitoids from the Western Domain of the Kaapvaal Craton, Southeastern Botswana: Implications for crustal evolution

SHRIMP U-Pb zircon dating of granitoids from borehole cores from the Amalia-Kraaipan granite-greenstone terrain of southeast Botswana yielded dates of: 2939±9 Ma for the biotite granite gneiss, 2943±9 Ma for the pink granite and 2782±6 Ma for the red granite. These dates define two main granite magmatic events in the Western Domain of the Kaapvaal Craton at ∼2.96 to ∼2.94 Ga and ∼2.78 Ga. In the Kaapvaal Shield the main magmatic events are dated at ∼3.5 to ∼3.3, ∼3.2 to ∼3.1, ∼2.96 to ∼2.94 and ∼2.78 Ga. The two domains were therefore affected by coeval igneous events at ∼2.96 to ∼2.94 Ga and ∼2.78 Ga and therefore the age of ∼2.96 to ∼2.94 Ga is taken to date their amalgamation along the Colesberg lineament. The ages of ∼2.78 Ga correspond to the emplacement of the Gaborone Igneous Complex of southeast Botswana, which is possibly related to the reactivation of or renewed igneous activity along the Colesberg lineament.