IT has been widely believed that no relatively young faulting has taken place in Sudan since the Mesozoic. The national Geological Map of Sudan, scale 1:4 million, 1963 edition, and the International Tectonic Map of Africa, scale 1:5 million, 1968 edition, show no faults in the territory and indeed the most recent comprehensive reviews of the structure of Sudan1,2 indicate that the late Phanerozoic formations are not significantly affected by faults.