Hydrothermal leaching in the Virginia mining district, New Mexico

The tourmaline-copper deposits of the Virginia mining district, New Mexico, lie along veins that were plugged and reopened repeatedly during the process of mineral deposition. At some time between the second and third stages of deposition the solutions removed calcite, sericite, and chlorite from interstitial and included fragments of altered wall-rock in the veins and thereby produced honeycombed box-works of first- and second-stage minerals, chiefly specularite, quartz, and chalcopyrite, on the walls of which minerals of later stages were deposited. It is suggested that the leaching solutions may have been acid and that the leaching was done by the fresh solutions of the third stage before their acidity was neutralized through reactions along their channelways. A mechanism is suggested to account for their presence at places previously traversed by alkaline or neutral solutions.