WEST MCARTHUR UPDATE April 17, 2018. Table 1: Winter 2018 Drill Hole Summary
WMA044: Sooty pyrite alteration is disseminated along local beds and coats local fractures between 401.2 m and 724 metres. A brittle fault zone from 717.0 m to 720.0 m is characterized by strong quartz dissolution and increased matrix clay in the bleached wallrock. In the basement, between 855.7 m and 876.1 m, a moderately to strongly chloritized and bleached anatectic granite is intruded by three intervals of strongly chloritized mafic dyke from 861.2 m to 862.1 m, 866.8 m to 870.2 m, and 871.6 m to 872.2 metres. Along the margins of the dykes, reactivated faults are characterized by clayhealed chaotic breccias with isolated reactivated clay gouge. WMA045: Below 761.1 m, bleached sandstone is overprinted by patchy red-brown secondary hematite to 768.6 m and transitions to strongly bleached sandstone with increasing weak to moderate pervasive sooty pyrite to 781.0 metres. The grey sandstone below 774.7 m has weak disseminated uranium (200-300 cps SPP2) with elevated radioactivity along select sooty pyrite coated fractures (600-1,000 cps SPP2). Table 1 summarizes the U 3 O 8 geochemical assay results. Moderately to strongly bleached sandstone with weak patchy sooty pyrite and hematite is intersected to 802.4 metres, below which the sandstone is pervasively bleached with weak pervasive sooty pyrite and weak patchy red-brown hematite to the sub-athabasca unconformity at 808.7 metres. Table 2: WMA045 U 3 O 8 Assay Grades (0.1% U 3 O 8 cut-off) Depth From (m) Depth To (m) Length (m) Average Grade (%U 3 O 8 ) Max Grade (%U 3 O 8 ) Hole Number WMA045 775.2 778.0 2.8 0.10 0.17 0.28 WMA045 780.0 781.0 1.0 0.13 0.14 0.13 GT (m%) WMA046: Several brittle fault zones are intersected from 329.3 m to 331.9 m, 351.5 m to 354.3 m and 357.4 m to 363.1 metres, characterized by steeply dipping limonite coated fractures, sandy clay gouges and quartz dissolution resulting in intervals of broken to unconsolidated core. Numerous 50 cm to 2 m wide fractured and broken zones are observed between 450.4 m and 548.4 m, largely coincident with desilicification and enhanced matrix clay. Weak sooty pyrite alteration is observed sporadically along select beds from 593.7 m to 721.6 metres. WMA047: Brittle fault zones characterized by structurally controlled quartz dissolution and clay alteration with intense adjacent silicification are intersected from 270.6 m to 272.7 m and 317.9 m to 319.0 metres. Strong pervasive bleached sandstone extends into the MFb to 555.7 m. A brittle fault zone from 554.0 m to 557.0 m is coincident with strong quartz dissolution (~50 cm lost core). WMA048: A fault zone from 381.5 m to 382.9 m is characterized by fracture-controlled quartz dissolution, limonite- and clay-coated fractures, dravitic gouge and adjacent silicification. Moderately to strongly bleached and weakly silicified sandstone with weak, patchy red-brown remobilized hematite, weak disseminated sooty pyrite, and localized limonite- and sooty pyrite-coated fractures is intersected from 557.0 m to 575.4 metres. In the basement, within the graphitic pelite, a 10 cm graphitic clay gouge overlies a narrow cataclasite at 828.2 metres. The graphitic pelite is associated with moderate
pervasive chlorite and sericite alteration, mineral type-controlled saussurite alteration and spaced sulfide stringers. WMA049-1: this hole continued WMA049, lost at 326 m. In WMA049-1, from 326.5 m to 334.2 m, the sandstone is moderately silicified leading up to a fault zone from 334.2 m to 335.5 m that is characterized by fracture-controlled quartz dissolution, unconsolidated core, limonite- and clay-coated fractures, and a 4 cm mosaic breccia. Several intervals of broken core, most notably between 358.8 m and 359.2 m and 365.0 m to 371.6 m, are characterized by weak to locally moderate fracture-controlled quartz dissolution, isolated sandy-clay gouge, and limonite- and clay-coated fractures. A fault zone from 523.8 m to 527.3 m is characterized by broken core with fracture-controlled quartz dissolution and limonite-coated fractures. An additional fault zone from 632.2 m to 638.0 m is characterized by broken core with moderate to strong fracture-controlled quartz dissolution resulting in unconsolidated and lost core, limonite-coated fractures, and localized sandy-clay gouge. Increased quartz dissolution and matrix clay content is associated with brittle fault zones from 724.4 m to 727.1 m, 730.5 m to 732.7 m and 735.5 m to 740.0 metres. Rare bedding-controlled sooty pyrite and patchy siderite staining are evident from 779.0 m to 819.0 metres. Elevated radioactivity (60-150 cps SPP2) is coincident with weak quartz dissolution from 792.8 m to 795.1 m and 812.8 m to 813.5 metres. In the basement, a metre wide section of silicification with a pitted desilicified overprint is centered on a fracture at 834.9 metres. Alteration intensity increases with depth, leading up to a ductile deformational zone from 850.5 m to 852.1 metres. This structural zone is characterized by banded strong hydrothermal hematite, sericite and chlorite alteration that obscures the protolith. A semi-brittle fault zone from 857.4 m to 862.4 m is hosted in pelitic diatexite, characterized by strong structurally controlled graphite and chlorite replacement, clay gouge and broken/friable core intervals. The lowermost 30 cm of the fault zone is associated with weakly elevated radioactivity (65-90 cps SPP2). WMA050: Structure in the MFd is limited to a 5 cm wide sandy-clay gouge at 173.8 m, and broken core with strong limonite along fractures from 231.6 m to 233.4 metres. In the upper MFc, from 419.0 m to 422.0 m, a fracture zone is characterized by structurally-controlled quartz dissolution with increased limonite and clay alteration. Below 455.2 m, the sandstone is variably bleached with irregular bands of weak to occasionally moderate bedding- and fracture-controlled sooty pyrite to 529.3 metres. Downhole Probing Data The downhole probing data below shows the mineralization in WMA045 some 25 metres above the unconformity, with a secondary peak close to the unconformity. A smaller peak is present at the inconformity. In WMA048, a broad peak of elevated gamma from 555 to 575 metres is interpreted as a probable zone of uranium enrichment related to an off-hole structure. A small gamma peak marks the unconformity. The gamma peak at 840 metres in WMA050 corresponds to a radioactive pegmatoid contact in the basement. Two small gamma peaks occur at the unconformity.
WMA045 Gamma 2,500 2,000 Gamma, cps 1,500 1,000 500 U/C 0 0 100 200 300 400 500 600 700 800 900 1,000 1,100 Depth, metres
WMA048 Gamma 350 300 250 Gamma, cps 200 150 100 50 0 0 100 200 300 400 500 600 700 800 900 1000 Depth, metres UC
WMA050 Gamma 350 300 250 Gamma, cps 200 150 100 50 0 0 100 200 300 400 500 600 700 800 900 1000 Depth, metres UC