DISTRIBUCIÓN DE ALTERACIÓN HIDROTERMAL Y MINERALIZACIÓN (Ag- Pb-Cu-Zn) EN LA SECCIÓN 5303350 DEL DEPÓSITO LOMA DE LA PLATA, DISTRINO MINERO NAVIDAD, CHUBUT

MAXIMILIANO MERCADO; JOSEFINA M. PONS; MARTA FRANCHINI; ANA LAURA RAINOLDI

Córdoba

Congreso; XIII CONGRESO DE MINERALOGÍA, PETROLOGÍA ÍGNEA Y METAMÓRFICA, Y METALOGÉNESIS; 2019

Asociación Mineralógica Argentina -AGA

Hydrothermal alteration and mineralization (Ag-Pb-Cu-Zn) in the section 5303350 of theLoma de la Plata deposit, Navidad district, Chubut. The mineralization of the epithermaldeposit Loma de la Plata is mainly hosted in permeable autobreccia and vesicle-rich andesitefacies of the Jurassic Cañadón Asfalto Formation. The analyzed section records the evolutionof the hydrothermal activity through three episodes, two of them are barren (E1 and E3) andone responsible for the Ag-Cu (Zn, Pb) mineralization (E2) possibly given by fluid mixing.Early hydrothermal alteration minerals suggest that oxidizing CO2-bearing neutral to alkalinefluids interacted with the host rock. Late illite-smectite to smectite zonation from fault zonesindicates a strong structural control for descending CO2-bearing near neutral steam heatedwaters. This deposit shares mineralogical and textural characteristics with Valle Esperanza,other example of distal mineralization style, and significant differences with Loma Galena,with proximal style mineralization.