Formation of the epithermal Sn-Ag-(Zn) mineralization at the Pirquitas deposit, Jujuy Province, NW Argentina - Fluid inclusion and isotopic constraints.

DESANOIS, LOUIS; LÜDERS, VOLKER; TRUMBULL, R.B.; CAFFE, P.J.

Quebec

Conferencia; 14th Biennial SGA Conference; 2017

SGA

The Pirquitas epithermal Sn-Ag deposit is located near the Bolivian border in the Argentinian Puna Plateau and used to be historically a great source of Sn and Ag in the country. The Pirquitas deposit is considered to be an analogue to the Bolivian Sn-Ag epithermal deposits but the origin of the ore-bearing fluids is still controversial. Fluid inclusions studies in quartz, Sn-Ag minerals and sphalerite from e.g. the Oploca vein system in transmitted and near infrared light show variable salinity from 10.6 to 0.8 wt.% NaCl equiv. and homogenous temperature from 274° to 190° C probably due to mixing of saline metal-rich fluids with meteoric water. Sulfur and lead isotopes analysis were performed in sulphides and sulfosalts. All results obtained are in agreement with data from Bolivian Polymetallic epithermal Ag deposits and suggest an mixture of magmatic and sedimentary sources.