Mineral Resource Update For The Trixie Deposit

Mineral Resource Update For The Trixie Deposit

MONTREAL – Osisko Development Corp. reports on mineral resource estimate (MRE) for the underground Trixie deposit within the wider Tintic Project, located in central Utah. The 2024 Trixie MRE incorporated an additional 1,674 underground chip samples over 1,678 meters (m) (5,507 feet (ft)) of underground development, and 7,385 m of drilling (24,229 ft) in 122 holes completed by the Company since the release of the initial Trixie MRE (2023 Trixie MRE).

Relative to the 2023 Trixie MRE, contained gold ounces in measured and indicated resources decreased by 29% and inferred resources decreased by 79% primarily due to lower estimated grades that incorporated an updated geologic model interpretation and conversion of inferred resources. Drill results and underground mapping from the 2023 exploration program improved the knowledge of the extent and distribution of mineralization, resulting in modeling improvements to both mineralization and the historical mine shape model.

Chris Lodder, President, said, “The 2024 Trixie MRE incorporates changes to our interpretation of the main mineralized structures and reflects better understanding of the structural controls of the deposit and realistic mining parameters following our exploration and test mining work in 2023. To date exploration and mining occurred on less than 10% of known mineralized structures in the west Tintic district and thus, we see significant precious metal potential at depth, on parallel structures to Trixie, along the Trixie and Sioux Ajax faults to the north and south, as well as around all historic high-grade gold mines in the West Tintic District. These high-grade gold targets, combined with the copper-gold porphyry potential where drilling is underway, and a large area of polymetallic carbonate replacement potential, illustrate that we have only scratched the surface in understanding the overall metal endowment potential of the Tintic district.”

In 2023, the Company completed a total of 6,028 m (19,776 ft) of underground drilling in 73 diamond drill holes at Trixie. Assays were finalized up to hole TRXU-DD-23-069 and were included in the 2024 Trixie MRE. The new drilling, mapping and historical data compilation improved the interpretation and revealed that there is significant potential for parallel high-grade gold fissure zones similar to T2 and adjacent to the existing mine development. Much of the Trixie area remains unexplored.

At Trixie, exploration potential remains highly prospective at depth near historical stopes that ceased mining at the water table. The Trixie deposit remains open to the north, along strike of T2, down dip below the historical 756, down plunge to the Survey Vein and additional, parallel structures are highly possible within the epithermal system. The Company continues to explore for additional high-sulphidation epithermal Au and Ag targets along the 4 km strike length of historical mines and has identified at least a dozen new drill ready targets from extensive data compilation and regional field work in 2023. Further work is recommended to test these targets (see Figure 3 for property wide historical deposits and exploration targets).

Copper-gold-molybdenum porphyry potential remains an exploration priority for the Company. One diamond drill rig is currently active at surface testing a porphyry target at Big Hill and is at a current depth of 1,180 m (3,872 ft). Assays are pending for this drillhole. One drill hole tested a copper-gold-porphyry target below Trixie and was drilled to a depth of 759.6 m (2,492 ft) when it crossed the Eureka Lily Fault to the east and out of the prospective alteration zone. Further drill testing of a copper-gold porphyry target at depth below the Trixie deposit is recommended to the west.

The development of the 1,390 m decline ramp at Trixie, completed in September 2023, significantly improving access to the underground workings for exploration development and drilling beyond the 625 level. The Company has advanced rehabilitation at the 750 level to allow for further underground diamond drilling to test for the down dip extent of the 756 zone and the porphyry target below Trixie.