Don Mario Geology

The Don Mario property is located within one of approximately 20 Lower to Middle Proterozoic schist belts in the Bolivian Shield. The Bolivian Shield forms the south-western edge of the Brazilian Precambrian Shield and has been subdivided into a Middle Proterozoic Paragua Craton, which is up to 270 kilometres wide and is bordered by two parallel orogenic belts of Middle to Upper Proterozoic age: the Sunsas Mobile Belt along its western edge and the Aguapei Mobile Belt along its eastern margin.

The Don Mario property lies within the southeast margin of the Sunsas Mobile Belt of the Bolivian Shield in a region characterized by highly deformed and metamorphosed Lower Proterozoic rocks of the Aventura Complex. The property covers a series of northwest-trending schist belts (Cristal and Eastern), orthogneiss (Patuju Domain) and a granite intrusive within an area of approximately 25 kilometres by 25 kilometres.

The UMZ copper-gold-silver deposit lies in the hanging wall of the LMZ shear zone within the Cristal Schist Belt. The UMZ Mine has been divided into 9 main rock types dominated by diopside-tremolite rock and massive tremolite rock. Other important rock types are dolomite/ophicalcite and talc schist. Part of the magnesio-silicate alteration and UMZ mineralization is weathered and is divided into four mineralization zones based on mineralogy: (i) the porous zone characterized by vuggy cavities left by the dissolution of calcite and locally abundant masses of white and orange-brown amorphous zinc carbonates and hydroxides including smithsonite; (ii) the oxide zone characterized by abundant malachite with lesser chrysocolla, azurite, native copper, cuprite, pitch limonite and silver sulfosalts; (iii) the transition zone featuring traces of pyrite, bornite, sphalerite and galena with weathered limonite and chalcocite coatings as well as minor copper oxides; and (iv) the sulphide zone consisting of dark-green tremolite with bornite, chalcopyrite, and sphalerite. Gold and silver grades are associated with chalcopyrite and bornite mineralization.

Location Map

Longitudinal Mine Plan Click to enlarge