Characterization of Arroyo Verde epithermal deposit: paragenesis, mineral geochemistry, geochronology and fluid inclusions in Lower Chon Aike volcanism, Argentin

PAVÓN PIVETTA, CECILIA; BENEDINI, LEONARDO; MARCOS, PAULO; CÓCOLA, MA. AGUSTINA; BARROS, MERCEDES V.; GREGORI, DANIEL A.; STRAZZERE, LEONARDO; COSTA DOS SANTOS, ANDERSON;; GERALDES, MAURO;

JOURNAL OF EARTH SCIENCE

CHINA UNIV GEOSCIENCES

Lugar: Pekin; Año: 2024 vol. x

1674-487X

Arroyo Verde epithermal deposit, in the North Patagonia region of Argentina, is located withinthe Lower Chon Aike Volcanism and is developed between 192.6 ± 2.5 Ma (mineralization hostrock) and 189.5 ± 2.6 Ma (overlying lava). Marifil Volcanic Complex is the host rock for theseveins, veinlets and breccias. This particular small deposit has developed low to intermediate sulphidation characteristics, with gangue mineral textures associated with several ore minerals.Electron probe microanalysis determines electrum, silver minerals such as acanthite, andtetrahedrite, related Ag-Cu minerals like jalpaite, mckinstryite, stromeyerite, and base metals likechalcopyrite, sphalerite, galena and pyrite. Fluid inclusions in quartz of two out of five events indicate that these low Jurassic veins were formed due to subtle boiling and dilution mechanisms and by low-salinity (3.4 to 6.7 wt% NaCl Eq) magmatic-hydrothermal fluid at 225 to 310 °C.The fluid inclusion measurements that indicate boiling (Event 3) were plotted, and based on thisdata, we interpret that the Arroyo Verde deposit has been eroded between 550 and 700 m. This particular character has not been previously recorded for other sectors of the eastern north