The Bethania silver deposit is a polymetallic (Ag-Pb-Zn-Cu-Au) hydrothermal deposit whose mineralogy, mineralization, textures, and associated alteration phases are consistent with the intermediate sulphidation (IS) epithermal geological model for volcanic-hosted precious metal deposits.

The Santa Elena mining concession covers Tertiary volcanic rocks that include andesite, dacite, and tuff. Outcrop exposure is best in areas of higher elevation (high cliffs, hill tops etc.) and along road or stream cuts, with much of the region covered by vegetation and Quaternary deposits (overburden).

All of the mineralized veins discovered to date are hosted by altered andesite and/or dacite with some anomalous mineralization hosted by siliceous bodies of stockwork quartz-breccia. The attention of past on-vein exploitation focused on the east-northeast trending veins but there are numerous north-northwest trending veins that have seen little if any exploration and testing.

The total lengths of the vein systems are not clear for all the veins and there is evidence that the northeast-trending veins (e.g., Española and Carolina) could extend several hundred meters along strike. In addition, many of the veins continue at depth as evidenced from underground mine development and the recently completed Phase diamond drilling program.

Ausenco (2017), noted that geochemical results indicate the potential for an igneous body of the copper porphyry type ex ........

The UBC methodology was used to select the most suitable mining method for the Santa Elena mine, considering the shape of mineralization, review of geotechnical information (RMR and characteristics of the footwall and hanging wall), distribution of grades and the general characteristics of the mine (for example, width, dip and depth).

The UBC Method is a modification of Nicholas's (1981) approach. According to Nicholas, each extraction method is classified according to the parameters of geometric distribution, grade of mineralization, location (distance to surface) and the geomechanical characteristics of the hanging wall and footwall.

The steps in the selection process considered the following:
• Description of the geometry of the mineralized material.
• Geomechanical characteristics of the mineralization, hanging wall and foot wall.

The mining methods likely to be applicable at Santa Elena through the UBC assessment were:
• Sublevel stopping;
• Cut-and-fill;
• SquareSet;
• Open Pit;
• Top Slicing;
• Sublevel Caving;
• Shrinkage stopping;
• Block Caving;
• Room and Pillar;
• Longwall.

From the analysis developed by the UBC methodology, the results of the applicable mining methods are referential to the base parameters analysed. The Conventional Cut and Fill, Square Set and Shrinkage mining methods offer the best value for the deposit. The importance ........

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