IsoEnergy Intersects Strongly Elevated Radioactivity in Multiple Holes Immediately Along Strike of Hurricane and In Step-Out Target Area D, 2.8 km East
Press Release
Toronto, ON, April 23, 2025 – IsoEnergy Ltd. (“IsoEnergy” or the “Company”) (TSX: ISO; OTCQX: ISENF) is pleased to announce the completion of its winter drilling program at the Larocque East Project (the “Project”), located in the eastern Athabasca Basin. The Company successfully completed 17 diamond drill holes, totaling 6,396 m, along the Larocque Trend (“Larocque Trend”), an important regional structure that hosts the Hurricane Deposit (“Hurricane” or the “Deposit”) containing a current Indicated Mineral Resource of 48.6 Mlbs at 34.5% U3O8 and an Inferred Mineral Resource of 2.7 Mlbs at 2.2% U3O8 (See “Qualified Person Statement” below). The Larocque Trend also hosts other notable high-grade occurrences including those on Cameco and Orano’s Dawn Lake joint venture. The Company’s drilling intersected strongly elevated radioactivity, in five holes, along the eastern extensions of the Hurricane Deposit main and south trends, as well as at Area D, 2.8 km east of Hurricane, highlighting the potential for additional zones of uranium mineralization both immediately on strike of Hurricane and regionally along the 9 km of the Larocque Trend on the Project.
Highlights
- Strong Radioactivity Intersected Along Hurricane Main and South Trends Confirm Structural Continuity and Supports Resource Expansion Potential (Figure 1)
- Main Trend – Drilling along the projected extension of the H and I faults intersected strong radioactivity, confirming potential continuity east of Hurricane. Hole LE25-194, located 80 m east of Hurricane, returned an average RS-125 reading on core of 3,100 cps over 0.5 m (Table 1) with a corresponding downhole probe maximum reading of 30,829 cps (Table 2). LE25-198 intersected up to 625 cps on core and 26,503 cps downhole probe 180 m east of Hurricane.
- South Trend – Drilling along the projected extension of the J and K faults intersected strong radioactivity, confirming potential continuity east of Hurricane. Hole LE25-207, located 240 m east of Hurricane, returned an average RS-125 reading on over 0.5 m on core of 8,800 cps and a corresponding downhole probe maximum reading of 30,096 cps, while LE25-210, drilled 480 m east of Hurricane, intersected up to 3,700 cps averaged over 0.5 m on core and a corresponding downhole probe maximum reading of 20,280 cps.
- Best Radioactivity Intercept to Date in Area D Outside of Hurricane Confirms Regional Potential
- Hole LE25-202 returned an average RS-125 reading on over 0.5 m on core of 6,200 cps and up to 28,782 cps downhole probe within that interval in Area D, a standalone zone located 2.8 km east of Hurricane (Figure 2).
- Geochemical Results Pending as IsoEnergy Prepares for Summer Drilling
- All core samples from the winter drill holes have been submitted, with results pending.
- Summer drilling will look to build on winter results as well as testing Target Areas E and F, 6 to 9 km east of Hurricane. Details of the summer program will be provided in due course.
- New Geophysical Interpretation Expands Larocque Trend Target Inventory
- A new geophysical model generated from joint inversion of historic electromagnetic and resistivity survey data has highlighted a previously underexplored conductive trend 800 m north of the main Hurricane conductor. The 2,500 m trend has only been tested by two historic drill holes, highlighting a compelling target for future testing (Figure 3).
Dr. Dan Brisbin, Vice President Exploration, commented, “The intersection of significantly elevated radioactivity, and associated alteration, along two of the targeted Hurricane trends east of the resource footprint and at Target Area D 2.8 km along trend from the Deposit highlight the potential for discoveries both along extensions to structures that control high grade mineralization at Hurricane and in additional target zones along the Larocque Trend. We look forward to resuming drilling this summer near Hurricane and in greenfield target areas along a six-kilometre prospective segment of the Larocque Trend – including at target areas E and F, where we decided to defer drilling until summer due to difficult ground conditions this winter”.
Figure 1– Location of winter 2025 drill holes with respect to the Deposit resource footprint (blue) and the ANT seismic low velocity zone in which the Deposit occurs, and projected Hurricane mineralization-controlling fault zones. RS-125 values are highest averages over 0.5 m intervals.
Figure 2 – Location of 2025 target areas and winter drill holes along the Larocque Trend, including drill holes in Target Area D, located 2.8 km east of the Deposit. In addition to targets near the Deposit, greenfield potential will be tested this summer in areas D, E and F along a six-kilometre segment of the Larocque Trend. RS-125 values are highest averages over 0.5 m intervals.
Table 1: Drill hole summary and RS-125 spectrometer results for holes with >350 cps.
Figure 3 – Joint resistivity – electromagnetic inversion model of the Larocque East project completed by Convolutions Geoscience and Computational Geosciences that highlights an untested 2,500m northern conductivity trend.
Hurricane Resource Expansion Drilling
A total of 13 holes were completed to test three interpreted structural trends at Hurricane (Figure 1). Four holes (LE25-194, 195, 198, 203) were drilled to test the projected eastern extension of the faults that control the main high-grade portion of Hurricane (the “Main Trend”). Seven holes (LE25-197, 199, 200, 201, 207, 208, 210) were drilled to test the projected extension of faults that control the Hurricane southern high-grade lens (the “South Trend”). Two holes (LE25– 196, 205A) were drilled to test a structure intersected in historic drill holes in the middle sandstone north of the Deposit at the unconformity (the “North Trend”).
Main Trend Highlights
Hole LE25-194 tested down-dip of structure and anomalous geochemistry intersected in LE21-89 and LE21-95A (Figure 4). Hole LE25-194 intersected widespread moderate to strongly bleached core through most of the sandstone. Strong pervasive bleaching, clay alteration and desilicification were intersected below 295 m. Moderate hematite and grey alteration, typical of Hurricane were intersected immediately above the unconformity associated with strongly elevated radioactivity over 3.5 m from 316.0 to 319.5 m which included a 0.5 m long interval with an average RS-125 spectrometer value of 3,100 cps and a corresponding 2PGA probe value of 30,829 cps. Mineralization styles include worm-rock replacement, fault-controlled and disseminated.
Hole LE25-198 drilled 100 m east of hole LE25-194, intersected widespread bleaching throughout the sandstone. Clay and limonite alteration, centered on a fault, were intersected from 259 to 263 m. A broad structural zone with continuous strong bleaching, desilicification, and clay alteration is present below 287 m. Fault-controlled hydrothermal hematite and weak grey alteration were intersected approximately 10 m above the unconformity, indicating the hole overshot the ideal target. Strong pervasive limonite and clay alteration continued to the unconformity at 316.5 m. The basement rock immediately below the unconformity is moderately argillitized and chloritized, with above-background radioactivity as measured on core and by downhole gamma probing extending from 314.0 m in sandstone down to 321.1 m in basement. Peak values recorded on drill core with the RS-125 spectrometer and with the 2PGA downhole probe are 625 cps average over a 0.5 m interval and 26,503 cps respectively. Hole LE25-198 is interpreted to have overshot the target, and potential for mineralization remains high to the north.
Hole LE25-203 tested north of hole LE25-194 and intersected strong bleaching, moderate clay and desilicification centred on structural zones below 283 m. Fault-controlled hematite alteration was intersected at 320.3 m. A peak of 4,809 cps was recorded on the 2PGA probe at 325.0 m, one metre below the unconformity.
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