Abstract: In 1957 uranium was discovered in the Vilcabamba district on the north flank of the Cordillera Vilcabamba, part of the Cordillera Oriental. This district contains principally small copper-nickel veins. Small lenses of uraninite occur in calcite veins cutting Permian Copacabana limestone. Uranium is most abundant marginal to centers of strongest copper-nickel mineralization. Leaching and oxidation are virtually absent because of Pleistocene glaciation. Four separate areas in which uranium has been identified are Huamanapi, Calderon, Minasmayo, and Negrillas. The Puntarayoc area, near Pampaconas, is considered a separate district. The deposits have been tested by trenching, drilling, and sampling concurrently with geologic reconnaissance mapping of the surrounding region.

Introduction: From the inception of the effort to utilize atomic energy Perú has been of interest as a possible source of radioactive raw materials because of its great variety and abundance of metals. Because of this and a desire at that time to develop additional supplies of uranium, a cooperative program to search for uranium deposits was initiated in 1953 by the Junta and the USAEC.