The Guanaceví silver-gold district comprises classic, high-grade silver-gold, epithermal vein deposits, characterized by low sulphidation mineralization and adularia-sericite alteration. The Santa Cruz mine property, which forms part of the main portion of the Guanaceví Mines Project, covers about a 3.0 km strike length of the Santa Cruz fault/vein system. The Santa Cruz vein itself has been traced for 5 km along trend, and averages approximately 3.0 m in width. High-grade mineralization in the system is not continuous but occurs in steeply northwest-raking shoots up to 200 m in strike length. A secondary mineralized vein is located subparallel and subjacent to the Santa Cruz vein, in the footwall, and while less continuous is economically significant in the Porvenir Dos and North Porvenir portions of the Project. The Santa Cruz vein is similar in many respects to other veins in the Guanaceví district, except that it is the only one to lie on the west side of the horst of Guanaceví Formation and associated facies, and it dips west instead of east. In the Porvenir Dos area and the Deep Santa Cruz mine workings, a low angle rhyolite crystal-lapilli tuff and andesitic contact occurs high in the hanging wall of the Santa Cruz vein indicating a fault contact with Guanaceví Formation, which obviously cuts the contact. The Santa Cruz vein is a silver-rich structure with lesser amounts of gold, lead and zinc. Mineralization has averaged 500 g/t silver and 1 g/t gold over 3 m t ........

Since 2013 long-hole stoping was introduced into the operations at Guanacevi. Over the last 2 years the Guanacevi mine has transitioned from an operation dominated by conventional cut and fill mining to one dominated by long hole stope methods.

The long-hole method increases production heights from typically 1.8m to up to 17m and at a reduced cost. Dilution and hanging wall failure is controlled using cemented 11m long fortifying cable bolts. Mining dilution has been estimated by Endeavour Silver Corp. (EDR) as variable with a minimum of 0.4m of over break dilution and a minimum operational width of 2.2m. Additional dilution is derived from the footwall especially in sill development, from occasional hanging wall failure and from re-mucking of floor fill. In general, dilution is estimated at being between 15% and 32%, while unrecoverable ore is estimated at approximately 5%. The dilution material in almost all cases is mineralized.

Cut-and-fill stope cuts are generally 15m long and 1.5 - 1.8m high, and long hole stopes are 15m long and 20m high (20m between levels measured floor to floor). Access to the stoping areas is provided by a series of primary and secondary ramps located in the footwall. The ramps have grades from minus 15% to plus 12%, with plus or minus 12% as standard. The crosscuts are 4 m by 4 m for the primary ramps and 3.5 m by 3.5 m for the secondary ramps.

In the upper parts of the mine, stope access is by short (10m to 40m) c ........

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