Abstract
Chemical, spectrographic, and isotopic analyses are presented for the Franzfontein alkali granite and constituent minerals. This rock has the chemical character of granties produced by liquid ⇌ crystal equilibrium. Dated at 1, 700±70m.y. by the constituent zircon, its crystallization formed part of a major period (the Huabian episode) of batholithic granite emplacement in northern South-West Africa. The occurrence of these crystalline rocks in the core of the Huab anticline defines the maximum possible age of the overlying Otavi Facies sediments, precluding their correlation with the Transvaal System of South Africa.