U-PB AND HF ISOTOPE CONSTRAINTS FOR EMPLACEMENT OF THE NKANDLA GRANITE, SOUTHEASTERN KAAPVAAL CRATON, SOUTH AFRICA

We report zircon ages and Hf isotopic compositions for the Nkandla Granite of the Ilangwe Granitoid/Gneiss Suite exposed to the southeast of Nkandla in northern KwaZulu-Natal, South Africa. The Ilangwe Granitoid/Gneiss Suite is intrusive into the Ilangwe Greenstone Belt along the southeastern margin of the Kaapvaal Craton. Zircons obtained from the Nkandla Granite yielded an upper intercept age of 3254 +/- 8 Ma, interpreted to be the age of intrusion, with evidence of lead loss events at 3086 17 Ma and in the Phanerozoic. The similar to 3.25 Ga age is consistent with late Palaeoarchaean ages obtained from similar granitoid units throughout the southeastern Kaapvaal Craton. The intrusive relationship with the adjacent Ilangwe Greenstone Belt provides a minimum age for the, as yet undated, greenstone succession. Initial hafnium isotopic compositions range from epsilon(Hf) = -2 to +7, indicating a role for both mantle input and crustal reworking.