Silver Dollar Resources Inc. reported underground sample assay results and preliminary geologic modeling of existing high-grade drill results in support of an exploration and mining strategy shift from open pit to underground at its 100%- owned La Joya Silver (Cu-Au) Project (the ?Property?) in the state of Durango, Mexico. A total of 16 channel samples were collected from the historic La Embotelladora mine workings, showing mineralization localized in ENE and NNE structural zones. Sample R-300 returned 2,753 grams per tonne (g/t) silver equivalent (AgEq) over 0.4 metres (m) representing the NNE trending zone.
Sample R-291 returned 328 g/t AgEq over 0.4m representing the ENE structural zone. These data combined with existing drilling results are aiding in the Company's ongoing strategy of transitioning La Joya from an open pit to an underground project by confirming high grade mineralization localization in a network of prospective structures. Ongoing geologic modeling will focus on validating this thesis through re-focused exploration planning.
Silver equivalent is calculated using the following metal prices in USD: Au $1,750/oz, Ag $22/oz, Pb $1.25/lb, Zn $1.50/lb, Cu $4.30/lb. Recoveries of Au 66%, Ag 93%, Pb 87%, Zn 84%, Cu 70% historically reported from Pan American Silver's La Colorada mine and Southern Silver's Cerro Minitas mine (Cu only) have been used in the AgEq calculation, and are assumed to be comparable to anticipated recoveries at La Joya. Silver Dollar has also completed preliminary numerical modeling of existing drillhole assay data to identify additional high-grade mineralization.
Numerical models were trended using preliminary vein modeling, which focused on a series of emerging E-W trends. Ongoing geologic modeling will incorporate other local trends, including a NNE structural trend, and the impact of stratigraphic-structural intersections on plunging mineral trends. Procedure, quality assurance/quality control and data verification: All rock samples were collected, described, photographed, and bagged on-site.
The samples were delivered by Silver Dollar staff to ActLabs in Zacatecas, Mexico for analysis. ActLabs is ISO 9001:2015 certified. Rock samples were crushed, pulverized and screened to -80 mesh at the lab, prior to analysis.
Gold is analyzed by a 30g Fire Assay with AA (atomic absorption spectroscopy) finish, then gravimetric finish if greater than 10ppm Gold. Silver and 34 other elements were analyzed using a four-acid digestion with an ICP-OES (Inductively Coupled Plasma Optical Emission spectroscopy) finish. Silver, lead, zinc, and copper over limits were re-assayed using an ore-grade four-acid digestion with ICP-AES (Inductively coupled plasma atomic emission spectroscopy) finish.
Control samples comprising certified reference samples and blank samples were systematically inserted into the sample stream and analyzed as part of the Company's quality assurance and quality control protocol.
