Unconformity-associated uranium deposits typically consist of uranium concentrations at the base of a Proterozoic sandstone sequence where it unconformably overlies pre- Middle Proterozoic metamorphic basement rocks, which commonly include graphitic pelitic units. The deposits are associated with faults or fracture zones.

The principal commodity is uranium. It is commonly accompanied by other metals, particularly Ni, Co, and As, but none of these constitute significant recoverable byproducts at present. Examples of important deposits of this type in Canada are Cigar Lake, Key Lake, Rabbit Lake, McArthur River (also known as P2 North), and Eagle Point, all in Saskatchewan (Fig. 7-1). The most notable foreign examples are the Australian deposits Ranger I and III, and Jabiluka I and II in the Pine Creek Geosyncline, Northern Territory (Ruzicka, 1993).