Granitic affinity mineralization in the central portion of the Colangüil batholith. Province of San Juan, Argentina

The central portion of the Batholith of Colangüil belongs to the Frontal Range and is located in the northwest of San Juan province, Argentina. It includes different granite units of Permian in age: Romo, Conconta, and Agua Blanca. These intrude the Cerro Agua Negra Formation, an Upper Carboniferous - Asselian sedimentary unit. These units are partially covered by volcaniclastic rocks of the Choiyoi Group, lower Permian-Triassic in age. The region was characterized by mineral extractions during the last century. Metalliferous mineralization has been recognized in the higher elevation areas of the Conconta and Agua Blanca plutons, with an early paragenesis of wolframite, fluorite, niobium, and quartz, and later deposition of scheelite, in quartz gangue. The latter was observed in the Agua Blanca pluton. The tectonic of the Cisuralian Permian San Rafael phase, compressive in nature, affected mainly the Cerro Agua Negra Formation. An oriented NW-SE fault array on the aforementioned igneous and sedimentary units stands out. Two regional fracturing axes limit laterally this sector of the batholith and match the location of the mineral deposits. A greater ascent of granite basement blocks can be seen to the south of the Conconta pluton and in the surroundings of the Agua Blanca pluton, based both on the intense erosion of its sedimentary host rock and by the little development of mineralization in the Romo sector. The fluid inclusion assemblages present in the veins of the Conconta and Romo sectors are linked with saline and carbonic fluid types, typical of the tungsten deposition cycle.