The talc deposits of the San José Belt (Colonia, Uruguay): a synthesis of their structural controls and geoeconomic potential

Depósitos de talco do Cinturão San José (Colonia, Uruguai): uma síntese de seus controles estruturais e potencial geoeconômico

Abstract

The present study reviews the main geological features, with emphasis on structural controls, affecting the geoeconomic potential of the green schist-hosted talc deposits of the western sector of the San José Belt (Colonia Department, Uruguay) located in the Narancio, Dante Ramos and Zafiro Sector mines. The analysis of the regional geology allows us to define two complementary genetic models for the talc deposits: i) hydrothermal alteration of basic volcanic rocks rich in magnesium, and ii) metasomatic processes in the contact between dolomites and acidic intrusive rocks. Finally, the productive history of the Narancio Mine is synthesized and the geometry, the volume of the lenticular bodies and the quality of the talc deposits of the Zafiro Sector are discussed with the purpose of allowing a better evaluation of its economic potential.