K-AR DATING OF RING COMPLEXES AND FAULT SYSTEMS IN NORTHERN KORDOFAN,SUDAN - EVIDENCE FOR INDEPENDENT MAGMATIC AND TECTONIC ACTIVITY

From an area of brittle shearing and ring complexes in Northern Kordof an, Sudan 28 K - Ar ages were calculated to determine the geochronolog y of tectonic and magmatic events. The age results for deformational e pisodes are 560, 340 and 255 Ma, whereas alkaline magma was intruded a t 280, 220 and 165 Ma. The incompatibility of age marks leads to the c onclusion that magmatic and tectonic activity in this area have to be regarded as independent events. This holds true even when all dated in trusions from the entire region are compared with post-Pan-African con tinental tectonic features.