Geology and uranium metallogeny in the Acosta region, Guachipas Departament, Salta

The localization of several anomalous uranium levels in Acosta zone, associated to the Balbuena and Santa Bárbara Subgroups sediments in the Salta Group, have been found by the geologist working for the Northwest Department of the National Commission of Atomic Energy between 2008 and 2010. These findings are located stratigraphically at the base of Yacoraite Formation and the upper levels of the Maíz Gordo Formation. Other findings are reported in the abnormal and thin levels of the Lumbrera and Mealla Formations. The anomalies identified on the floor of Yacoraite Formation correlate with the ore and copper values of the regional uranium level. Uranium mineralization is hosted in gray micaceous shales, dark brown pelites and organic matter- rich black levels, particularly where banks are interbedded with parallel laminated fine sandstones. Two anomalous sections were identified in the Maíz Gordo Formation, the first one located in the basal part of the upper third part of the unit and the second, close to the top of the Formation. The anomalies of the first section have a large areal distribution and show greater interest from an economic point of view. (authors)