The silver–gold epithermal mining district, Manantial Espejo, is located southwest of the Deseado Massif, Patagonia. The district is set into Jurassic volcaniclastic rocks of the Bahía Laura Group. A geological map of the district, at a scale of 1:50,000 drawn over a base map prepared from the fusion of satellite imagery and aerial photographs, is included. A suite of andesitic to rhyolitic eruptive units was identified, with prevailing high-grade rhyolitic ignimbrites. Travertine levels show the beginning of a hot-spring system in the region. Quartz veins, with typical crustiform–colloform banded structures, fill WNW, sub-vertical, normal faults, originating from extensional tectonics. The silicification of travertines, tuffs and breccia is the most common hydrothermal alteration.Facultad de Ciencias Naturales y Muse
