Opodepe Project – Sonora, Mexico
The El Creston and Teocuitla Claims are separate operations but together they are known as The Opodepe Project.
The project represents a three-dimensional prospect for Starcore with possibilities as a moly deposit, as a property with gold showings, and thirdly as a project with the potential for copper porphyry at depth.
The El Creston property is comprised of nine claims covering approximately 11,364 hectares – Meztli, Meztli 1, Meztli 2, Meztli 3, Meztli 4, Meztli 6, Lorenia, Alma and Letty. It is a well-known and defined Molybdenum deposit, but the property had never been explored for precious metals.
The Teocuitla property is comprised of four claims covering approximately 3,087 hectares – Teocuitla, Teocuitla 2, Angel and Tlaloc 2. These are located beside the El Creston Meztli 4 claim in the northwest part of Starcore’s property. This particular property is more commonly known as the Teocuitla claims. These claims had not been previously explored for precious metals, presenting an opportunity for exploration, particularly for gold and silver.
Teocuitla – Sonora, Mexico
Geology & Mineralization
The geology of the Opodepe Project is focused on precious metals and is located in the north zone of Meztli 4 claims where the El Creston deposit is located. The host rock is a granite (Late Cretaceous – Early Tertiary). Within this lithology and distant to the Mo-Cu Porphyry deposit, there is an Epithermal Low Sulfidation deposit. The geological behavior is a shear zone.
The targets discovered in the Project are filon type. Each of these discovered targets were identified as a surface anomaly zone, however, the true potential is found in length of the structures and diversification of structures that are presented in the Starcore concessions.
The mineralization observed in the different Starcore structures is variable, but the behavior is always vein-type, and the mineralization occurs mainly on: silicification areas, oxides with gray quartz fragments zones, formal quartz veins and propylitic alteration zones.
Exploration Status
The Company conducted a six-month exploration plan in 2021 which included more than 1600 samples taken in the outcrops of nine new discovered veins in the Meztli 4 and Teocuitla claims, with a focus on gold and silver orebodies.
The first stage of drilling focused on the upper part of the veins of the zone and has been considered as recognition drilling. A total of 3,289.6 m was drilled in 25 short holes.
In 2022, drilling was focused on the zone of the veins which the geologists had considered as favorable zones to find economic reserves. These holes were longer than the first stage including two new veins, MIDAS and El ORO, both in the Teocuitla concession.
Since 2022 no further drilling has been completed on the Teocuitla claims. However, the Company continues to keep them in good standing.
El Creston – Sonora, Mexico
Overview
In February 2015, Starcore International Mining, through its acquisition of Creston Moly Corp, acquired a 100% interest in the El Creston Property, a large Molybdenum project in Sonora, Mexico. The El Creston Property hosts a 5.5 km long x up to 1.5km wide trend of hydrothermal alteration in which several zones of molybdenum +/- copper +/- silver mineralization occur.
Location
The El Creston Project is located in north-central Sonora State in north-western Mexico. The property is about 145 kilometres (“km”) by road north-northeast of Hermosillo, the capital of Sonora State, 5 km southwest of the village of Opodepe. Access from Hermosillo is via Highway 15 north from Hermosillo 70 km to Carbo junction. From the junction, a paved road is followed east for 52 km to Rayon, then north along a well-maintained gravel road for 21 km to the junction with a secondary unpaved road crossing the San Miguel River 5 km south of Opodepe that leads to the El Creston Project.
The Property occurs within the Sonoran Desert along the western foothills of the Sierra Madre Occidental Mountain Range. The eastern portion of the property overlies the San Miguel River Valley. Local elevations range from 650 metres at the valley floor to in excess of 1100 metres at some of the higher mountain peaks. Vegetation consists primarily of cactus and scrub timber.
Geology & Mineralization
Regionally, the area is part of the Basin and Range Province which is an extensional terrain of fault-bounded ranges and intervening valleys in the western United States that extends southward from Nevada and Utah southwards into the states of Sonora and Chihuahua, Mexico. In northern Mexico, this province is bifurcated by the Sierra Madre Occidental, a north-northwest-trending mountain range about 1,200 km long and 200 km to 300 km wide that forms the spine of northern Mexico. The Creston property lies in the western or Sonoran portion of the Basin and Range Province, close to the western flank of the Sierra Madre Occidental.
The predominant lithologies known at El Creston include metamorphic rocks of Precambrian and perhaps Paleozoic age, intrusions of various compositions, dikes, and breccias of Paleozoic and Tertiary age, and recent conglomerate, talus, and landslide deposits.
Phyllites, quartzite, gneisses, and metavolcanic rocks were intruded by the Creston granite, which has a weakly developed gneissic texture. The Creston granite has been altered and mineralized, hosting most of the presently defined molybdenum mineralization in the Main deposit, the older metamorphic rocks intruded by the Creston granite are only locally altered and mineralized.
There are two principal styles of mineralization at the Main deposit: predominantly subvertical quartz-molybdenite-pyrite veinlets hosted by the Creston granite and molybdenite-pyrite within the quartz matrix of magmatic-hydrothermal breccia of the East Breccia body, which cuts the Creston granite. While minor amounts of chalcopyrite accompany the molybdenite mineralization, more significant quantities of copper (“Cu”) occur as chalcocite replacements of pyrite within secondary enrichment blankets that parallel present-day topography. Some chalcocite also occurs below the enrichment blankets, primarily along permeable structural zones such as the Ordoñez fault zone.
Exploration Status
As of April 2025, the Company has expended its budgeted US$500,000 for El Creston, including annual concession fees, and continues to maintain the claims in good standing. In the next phase of exploration, the Company will endeavour to confirm the presence of a copper porphyry at depth, which will now include surveys, geophysical studies of magnetometry, and the development of new geological models from existing drillhole data.
Technical Reports
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Independent Technical Report for the El Creston Molybdenum Project, Sonora, Mexico as of September 30, 2022
The San Juan Nepomuceno (The Tortilla Project) – Queretaro, Mexico
Overview
In October, 2025 Starcore announced that through its wholly-owned Mexican subsidiary, Compañia Minera Peña de Bernal, it had finalized a ten-year lease on land holdings that included a historical past-producing silver mine located in Queretaro, Mexico. The lease encompasses six mineral claims and two properties comprising what is commonly known as the San Juan Nepomuceno Project (the “Tortilla Project”).
Location
The Tortilla Project includes a historical mine situated 150 km from the capital, Santiago de Queretaro, 40 km northeast of the San Martin Mining Unit and 5 km west of the La Negra Mine. Mining activity in the area dates back to 1557 with records of continuous operation until 1870 under Spanish control. During this period, the deposit was known as El Doctor Mine.
Towards the end of the 19th century, a British company, O. J. Braniff, resumed exploration activities and installed a processing plant to process minerals from the San Juan Nepomuceno and Santo Entierro mines. However, operations only lasted two years. There are no historical production records.
Geology & Mineralization
The average grades associated with the San Juan Nepomuceno structure are as follows: Au: 0.54–0.95 g/t, Ag: 590–1,200 g/t. The reported average widths range around 1.20 meters; however, there is physical evidence that the thickness may reach 5.0 or even more meters.
The San Juan Nepomuceno structure has a N290° orientation and a dip that varies between 15° and 30°, dipping southwest. The main structure was developed within the old mine, which shows an average geological thickness of 5 meters. The recorded longitudinal extension is 80 to 120 meters, while vertically it has been recognized to a depth of 700 meters, following the dip of the structure historical exploitation works were carried out partially and artisanal, leaving the potential and economic values at the extreme and basal part open as exploration targets.
The mineralized zone is hosted by the Soyatal Formation. The main potential of the San Juan Nepomuceno structure lies in the lateral extensions, which could reach up to 3 kilometers in length. In the deepest part of the workings, the structure continues to show high economic values, indicating a mineralizing system still open at depth. During the development of the main tunnel, a secondary structure parallel to the main vein was identified. This structure presents grades of up to 700 g/t silver (Ag) and an average thickness of 0.70 meters, reinforcing the interest in the deposit’s multiple structural system.
Another area with significant potential is the El Doctor thrust, located 500 m to the west and a geological, lithological, and structurally primed target for mineralization development. A second priority exploration target is also identified in the area known as La Cabalgadura hanging wall, corresponding to El Doctor Formation. This biological unit is considered more favorable for hosting larger ore bodies with economic potential, compared to the Soyatal Formation.
Exploration Status
The Company conducted metallurgical testing at its plant using cyanidation as the testing process. After a 72-hour testing period, the results indicated a recovery of 56.25% for gold and 78.23% for silver. Leaching with granular activated carbon significantly enhanced gold recoveries, increasing to 79.85%, while silver recoveries rose to 84.75%. This demonstrates that the mineral can be effectively processed using the CIL (carbon-in-leach) process. The San Martin mine is in a crucial location as the plan is to transport the mineral to the mine for processing.
Ongoing work has also resulted in two main mineralized zones being identified:
- Oxides Zone: Average silver grade: 424 g/t, average gold grade: 0.51 g/t, average sampling width: 1.45 m (width of gallery, not of the entire structure)
- Sulfide Zone: Average silver grade: 973 g/t, average gold grade: 0.43 g/t, average sampling width: 2.80 m
The grades tend to increase with depth, suggesting greater potential at lower levels which mirror what historical records have indicated.
Preliminary metallurgical tests were carried out by flotation on representative samples from the sulfide zone, with favorable results: silver recovery: 91.49% and gold recovery: 48.25%.
These results demonstrate that the ore is metallurgically treatable by conventional methods, representing a strong opportunity for economic development.
The Company is excited about the potential this initiative represents for sustained growth and long-term value creation. If the technical and metallurgical analyses are confirmed, we believe this investment will deliver significant returns for our shareholders.
