Mineralogy, structural control and age of the Incachule Sb epithermal veins, the Cerro Aguas Calientes collapse caldera, Central Puna

SALADO PAZ, NATALIA; PETRINOVIC, IVÁN; DO CAMPO, MARGARITA; BROD, JOSÉ AFFONSO; NIETO, FERNANDO; DA SILVA SOUZA, VALMIR; WEMMER, KLAUSS; PAYROLA, PATRICIO; VENTURA, ROBERTO

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2017

0895-9811

The Incachule Sb epithermal veins is located near to the N-E rim of the Cerro Aguas Calientes collapsecaldera (17.5e10.8 Ma), in the geologic province of Puna, Salta- Argentina. It is hosted in Miocene felsicvolcanic rocks with continental arc signature. The district includes twelve vein systems with mineralizationof Sb occurring in hydrothermal breccias and stockwork. The veins are composed of quartz-sulfidewith pyrite, stibnite and arsenopyrite. All around the veins, wall rocks are variably altered to clayminerals and sulfates in an area of around 2.5 km wide by more than 7 km long. The hydrothermalalterations recognized are: silicic, phyllic and argillic.The veins are characterized by high contents of Sb, As, and Tl and intermediate contents of Pb-Zn-Cu,and traces of Ag and Au. Homogenization and ice-melting temperatures of fluid inclusions vary from125 C to 189 C and 2.4 C to 0.8 C. The isotopic data indicated a range of d34S 3.04? to þ0.72?consistent with a magmatic source for sulfur.We present the firsts K-Ar ages for hydrothermal illite/smectite mixed layers (I/SR1, 60% illite layers)and illite that constrain the age of the ore deposit (8.5e6.7 ± 0.2 Ma).The data shown here, let characterized the Incachule district as a shallow low sulfidation epithermalsystem hosted in a collapse caldera. Our data also indicate that mineralization is structurally controlledby a fault system related to the 10.3 Ma collapse of Aguas Calientes caldera. The interpreted local stressfield is consistent with the regional one.