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 ........

Avino is currently mining on the Avino Vein using sublevel stoping and room and pillar mining methods. Levels are spaced 20 m apart and accessed via crosscuts from the main ramp. Access into the Avino Vein is through the ET Mine.

The room and pillar mining method is used on each sublevel to mine out each level to the extents of the mineralization. Long holes are then drilled between the sublevels to facilitate blasting of the mineralization between the sublevels. In 2020, Avino reported it will transition from development-style mining to full-scale production mining to feed all four circuits using the long hole retreat mining method, which is anticipated to incur lower mining costs.

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The processing plant consists of conventional crushing, grinding, flotation, and dewatering circuits. After upgrading, the plant now has a total capacity of 2,500 t/d for processing the materials from the Avino Veins.

The four circuits include the following:
- Circuit #1 was used to process materials from the San Gonzalo Mine, which has been stopped since the end of 2019. The circuit was used to produce a lead concentrate containing gold and silver, as well as a zinc concentrate. The circuit has now been modified to process materials from the ET Mine and produces a copper flotation concentrate containing silver and gold. The processing rate is 250 t/d.
- Circuit #2 is used to process mill feed from the ET Mine and produces a copper flotation concentrate containing silver and gold. The processing rate is 250 t/d.
- Circuit #3 is used to process materials from the ET Mine and produces a copper flotation concentrate containing silver and gold. The processing rate ........