The Avino concession is located within a 12 km (north–south) by 8.5 km (east–west) caldera. The Property contains numerous low-sulphidation epithermal veins, breccias, stockwork, and silicified zones that grade into a “near porphyry” environment, particularly in the Avino Mine area. The caldera has been uplifted by regional north-trending block faulting (a graben structure), exposing a window of andesitic pyroclastic rocks of the lower volcanic sequence within the caldera. The Lower Volcanic Sequence is overlain by the Upper Volcanic Sequence, consisting of rhyolite to trachyte flows and extensive ignimbrites and intruded by monzonite bodies.
AVINO VEIN
Geology and mineralization of the Avino Vein are summarized from Slim (2005d).
The Avino Vein is 1.6 km long and 60 m wide on the surface. The Avino Vein is the most striking and important example of the epithermal mineralization of the district whose structures are normally weathered and leached in their upper section as a result of contact with atmospheric waters producing a band of oxide minerals and zones of supergene enrichment to a depth of about 70 m.
In the oxide portion of the Avino Vein, the common minerals encountered include hematite, limonite, anglesite, and copper carbonate in white or green, somewhat chloritized, quartz zones. The common primary and secondary minerals encountered are argentite, bromargyrite, chalcopyrite, chalcocite, galena sphalerite, bornite, native silv ........
