The Waterbury Lake property is owned by Denison (65.92%), Korea Waterbury Uranium Limited Partnership (“KWULP”) (34.06%), as limited partners, and Waterbury Lake Uranium Corporation (“WLUC”) (0.02%), as general partner, of the Waterbury Lake Uranium Limited Partnership (“WLULP”). Denison is the operator of the project and holds a 60% interest in WLUC. KWULP consists of a consortium of investors in which Korea Hydro & Nuclear Power ("KHNP") holds a majority position. Percentage interests were calculated as at October 31, 2018.
The J Zone uranium deposit was discovered during the winter 2010 drill program at Waterbury Lake. The second drill hole of the campaign, WAT10-063A, was an angled hole drilled from a peninsula extending into McMahon Lake. It intersected 10.5 metres of uranium mineralization grading 1.91% U3O8, including 1.0 metre grading 13.87% U3O8 as well as an additional four meters grading at 0.16% U3O8. The J Zone deposit discovery was made after Hathor Uranium had discovered the adjacent Roughrider Uranium deposit under the northern limb of McMahon Lake in 2008.
The J Zone deposit is currently defined by 268 drill holes intersecting uranium mineralization over a combined east-west strike length of up to 700 metres and a maximum north-south lateral width of 70 metres. Uranium mineralization is generally found within several metres of the sub-Athabasca unconformity at depth ranges of 195 to 230 metres below surface at the J Zone. Mineralization occurs in three distinct settings: (1) entirely hosted within the Athabasca sediments, (2) entirely within the metasedimentary gneisses or (3) straddling the boundary between them.
The deposit trends roughly east-west (080°) concordant with the basement metasedimentary corridor and a cataclastic graphitic fault zone. A 45 metre east-west intermittently mineralized zone occurs in the target area formerly known as Highland roughly separating the J Zone into two segments referred to as the eastern and western lenses which are defined over east-west strike lengths of 260 and 318 metres, respectively. A thin zone of unconformity uranium mineralization occurs to the north of intermittently mineralized zone which is interpreted to represent a mineralized block that has been displaced northwards by faulting and is referred to as the mid lens.
Mineralization thickness varies widely throughout the J Zone and can range from tens of centimetres to over 19.5 metres in vertical thickness. In cross section, J Zone mineralization is roughly trough shaped with a relatively thick central zone that corresponds with the interpreted location of the cataclasite and rapidly tapers out to the north and south. Locally, a particularly high-grade (upwards of 40% U3O8) but often thin lens of mineralization is present along the southern boundary of the metasedimentary corridor.
The Huskie uranium deposit was discovered by Denison during the summer of 2017 and is located approximately 1.5 kilometres to the northeast of the property's J Zone uranium deposit.
The Huskie deposit is entirely hosted within competent basement rocks below the sub-Athabasca unconformity primarily within a faulted, graphite-bearing pelitic gneiss (“graphitic gneiss”) which forms part of an east-west striking, northerly dipping package of metasedimentary rocks flanked to the north and south by granitic gneisses. The Athabasca Group sandstones that unconformably overlie the basement rocks are approximately 200 metres thick. The deposit comprises three stacked, parallel lenses (Huskie 1, Huskie 2 and Huskie 3) which are conformable to the dominant foliation and fault planes within the east-west striking graphitic gneiss unit. The drilling to date suggests the grade, thickness, and number of lenses present is controlled by the presence of northeast striking faults which cross-cut the graphitic gneiss unit. The northeast striking faults identified at the Huskie deposit are interpreted to be part of the regional Midwest structure.
The deposit occurs over a strike length of approximately 210 metres, dip length of approximately 215 metres and has an overall true thickness of approximately 30 metres (individual lenses vary in true thickness of between 1 metre and 7 metres). The deposit occurs at vertical depths ranging between 240 and 445 metres below surface and 40 to 245 metres below the sub-Athabasca unconformity. The high-grade mineralization within the lenses is comprised of massive to semimassive uraninite (pitchblende) and subordinate bright yellow secondary uranium minerals occurring along fault or fracture planes, or as replacement along foliation planes. Disseminations of lower grade mineralization occur within highly altered rocks proximal to fault planes. The mineralization is intimately associated with hematite, which both occur central to a broad and pervasive alteration envelope of white clays, chlorite and silicification.
Estimated Mineral Resources
Grade % U3O8
1000 Lbs U3O8
(1000 Lbs U3O8)
- Mineral resources are not mineral reserves and have not demonstrated economic viability. All figures have been rounded to reflect the relative accuracy of the estimates.
- The J Zone Mineral Resource estimate was prepared for the Company by GeoVector Management Inc. in accordance with CIM Definition Standards (2005) and NI 43-101 with an effective date of September 6, 2013.
- The audited Mineral Resource Statement for the Huskie deposit was prepared by Dr. Oy Leuangthong, PEng and Mr. Cliff Revering of SRK Consulting (Canada) Inc. with an effective date of October 17, 2018.
- Mineral resources for the J Zone deposit are reported above a cut-off grade of 0.1% U3O8.
- Mineral resources for the Huskie deposit are reported above a cut-off grade of 0.1% U3O8.
Technical Report with an Updated Mineral Resource Estimate for the Waterbury Lake Property, Northern Saskatchewan, Canada, dated December 21, 2018, by Serdar Donmez, P.Geo., E.I.T., Dale Verran, Pr.Sci.Nat., P.Geo., and Paul Burry, P.Geo. of Denison Mines Corp., Oy Leuangthong, P.Eng and Cliff Revering, P.Eng of SRK Consulting (Canada) Inc., Allan Armitage, P.Geo of SGS Geostat, and Alan Sexton, P.Geo of GeoVector Management Inc.