Oroco Resource estimates Santo Tomas at 487.3 Mt of 0.36% CuEq, Mexico

Oroco Resource Corp. [OCO-TSXV; ORRCF-OTCQB; OR6-BF] released a mineral resource estimate (MRE) for its Santo Tomas porphyry copper project in Sinaloa state, Mexico, prepared by SRK Consulting (U.S.) Inc. of Denver, Colorado.

Commenting on the MRE, Richard Lock, CEO, stated: “This mineral resource estimate represents a key milestone for the company, and the culmination of extensive legal property work and geological investigation and analysis. We are very pleased with the results, which confirm our belief that we have a substantial resource at Santo Tomas that is exposed at or near surface and has robust potential to support a large, low-cost, open-pit mining operation.”

Highlights of the MRE include: Total indicated sulphide resources of 487.3 million tonnes (Mt) of 0.36% equivalent copper (CuEq) at a cut-off grade of 0.1%  copper, factoring in recovery parameters for a flotation copper concentrate product based on metal recoveries of 84.3% copper, 66% molybdenum, 57% gold and 54% silver. The indicated resource, all contained within an economic pit shell, results in contained metal of 3,864 million pounds (Mlb) of CuEq.

Total inferred sulphide resources of 599.9 Mt of 0.36% CuEq at a cut-off of 0.15% Cu, factoring in the recovery parameters. The inferred resource, all contained within an economic pit shell, results in contained metal of 4,697 Mlb of CuEq.

Total contained metals. The indicated resource CuEq is calculated from total contained metals of 3,400 Mlb Cu, 91.9 Mlb of molybdenum, 392,800 troy ounces gold and 32.719 million oz of silver. The inferred resource CuEq is calculated from total contained metals of 4.171 billion lb Cu, 95.6 Mlb of molybdenum, 500,600 oz gold and 38.458 Moz of silver.

Significant expansion from the historical resource. The MRE has returned a current resource that is significantly larger than the historical resource discussed in the company’s April 2020, technical report.

Significant potential to expand the resource. The MRE confirms the high potential of the project, which remains open to the north and south, with clear potential for further expansion of the resource and further conversion of MRE inferred resources to an indicated resource classification.

Mineralization has been identified outside the current economic pit shell. Further exploration drilling and associated work programs will be needed to define additional mineral resources.

A total of 62,678 metres of drilling in 156 holes has been completed at the Santo Tomas Project. The drilling data represents a combination of historical holes and holes drilled by Oroco from 2021 to 2023.

The MRE is broken down by the two primary mineralization zones identified at the Santo Tomas project: North Zone and South Zone. These zones display similar mineralization styles but are physically separated by localized post-mineralization faults. The MRE is inclusive of mineralization that partially projects under the Huites Reservoir. It is not anticipated that the upcoming mine plans will access this material. Approximately 10% of the indicated and inferred resource is contained within a pit shell that would make incursion upon the reservoir when compared with a pit shell prepared to avoid incursion upon the reservoir zone.

As a result of the robust MRE, the company plans to proceed with a Preliminary Economic Assessment. Ausenco Engineering USA South Inc. has undertaken preliminary metallurgical work on drill core samples collected from representative lithologies and mineralized intervals at North Zone which were used in the MRE, CuEq calculation and pit optimization parameters. Preliminary recovery parameters to date are 84.3% Cu, 66% Mo, 57% Au, and 54% Ag. The company plans additional drilling programs to further define mineral resources, geotechnical parameters, and metallurgical recoveries. Additional work is required to evaluate a possible oxide copper resource.

The company holds a net 85.5% interest in the collective 1,172.9-hectare Core Concessions of the Santo Tomas project in northwestern Mexico. The company also holds an 80% interest in 8,154.3 hectares of mineral concessions surrounding and adjacent to the Core Concessions (for a total project area of 23,048 acres).

The property is reached by a 32-km access road, part of which was originally built to service Goldcorp’s El Sauzal Mine in Chihuahua State.