Summary: The following ages determined by the complete lead method have been accepted for minerals from a number of localities: uraninite, Nkana, Northern Rhodesia, 522±15 m.y. ; brannerite, Kansanshi, Northern Rhodesia, 503±15 m.y. ; uraninite, Shinkolobwe, Katanga, 642±20 m.y. ; davidite, Mavuzi, Mozambique, 578±15 m.y.; monazite, Monkey Bay, Nyasaland, 597±25 m.y.; samarskite, north-west Kenya, 635±25 m.y. The significance of the results is briefly considered.