Summary:
Tthe Heldeth Túé
The Tthe Heldeth Túé is primarily comprised by an east-west trending faulted package of variably graphitic and pyritic metasediments bounded by orthogneiss to both the north and south. The pelitic metasedimentary assemblage, which ranges in thickness from 90 to 120 m and is moderately steep dipping to the north includes, from north to south, a roughly 50 m thick pelitic gneiss underlain by 20 m thick graphitic pelitic gneiss, underlain by a 10 to 15 m thick quartz-feldspar wedge underlain by 20 m thick graphitic pelitic gneiss, underlain by a 15 to 25 m thick pelitic gneiss, then back into orthogneiss. There are discontinuous offsets at the unconformity that range from a few metres to as much as ten metres.
The Tthe Heldeth Túé deposit is currently defined by 268 drill holes intersecting uranium mineralization over a combined east-west strike length of up to 700 m and a maximum northsouth lateral width of 70 m. The deposit trends roughly east west (080°) in line with the metasedimentary corridor and cataclastic graphitic fault zone. A 45 m east-west intermittently mineralized zone occurs in the target area formerly known as Highland roughly separating the Tthe Heldeth Túé into two segments referred to as the eastern and western lenses which are defined over east-west strike lengths of 260 and 318 m, 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
Huskie 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 east-west trending faulted package of pelitic gneisses ranges in thickness from 40 to 60 metres and is moderately steep dipping to the north. There are discontinuous offsets at the unconformity that range from a few metres to as much as fourteen metres.
The Huskie deposit mineralization is entirely basement-hosted comprising 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 high-grade mineralization within the lenses is comprised of massive to semi-massive 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.
Sub-Athabasca Crystalline Metamorphic Basement
The Waterbury Lake project is located over the Mudjatik-Wollaston Transition Zone (MWTZ). This zone is currently host to all of the producing uranium deposits in the Athabasca Basin. The basement beneath the Waterbury Lake project is comprised of approximately northeast trending corridors of metasediments wrapping around orthogneissic domes and locally in the Discovery Bay trend an east-west trending corridor of metasediments bounded to the north and south by thick zones of orthogneiss that, based on interpretation of aeromagnetic images, may represent two large dome structures.
The metasedimentary corridor is interpreted as the steeply north-northwest dipping limb of an antiformal fold structure wrapping around the southern orthogneiss dome. The north and south Archean orthogneiss bodies are typically composed of 25 % quartz, 65 % plagioclase and alkali feldspar combined and approximately 10 % biotite with trace garnet. The orthogneiss commonly contains thin pegmatite intrusions and lenses of non-foliated quartz-feldspar granofels. No significant structures or fault zones have been intersected in the orthogneiss bodies.
Athabasca Group Sandstone
The Athabasca Group sandstone, ranging from 200 to 370 m in thickness in the Waterbury Lake Project area, is comprised of Manitou Falls Formation sandstones and conglomerates of the MFb (Bird) Member. The upper 100 to 140 m of sandstone is typically bleached to a buff colored, and is medium- to coarse-grained, quartz-rich, and cemented by quartz overgrowths, clay minerals (kaolin, illite), and/or hematite. Bleaching of the sandstone (removal of diagenetic hematite) is noted along much of the Tthe Heldeth Túé and Huskie zone trends.
Quaternary Geology
The surficial sediments in the Waterbury Lake Project area consist of a thin layer of Quaternary till and glaciofluvial sand and gravel. Low relief drumlins and eskers are the dominant surficial feature in the area. The till is typically brown, variably compact to dense and is composed of silt, sand, gravel, and boulders.
The Athabasca Basin is one of the principal uranium producing districts in the world (Jefferson, et al., 2007b) and it contains the world’s largest high-grade unconformity-type (also called unconformity-related) uranium deposits (McArthur River and Cigar Lake). The Midwest uranium deposits (Midwest Main and Midwest A) are classified as typical egress-style unconformity-type uranium deposits that formed through diagenetic-hydrothermal basementsandstone interaction (Hoeve & Sibbald, 1978); (Hoeve & Quirt, 1984); (Hoeve & Quirt, 1987). The IAEA definition of this type of deposit is: “Unconformity-related deposits comprise massive pods, veins, and/or disseminations of uraninite spatially associated with major unconformities that separate Paleoproterozoic metamorphic basement from overlying PaleoproterozoicMesoproterozoic siliciclastic basins” (IAEA, 2009)
The deposits range from egress-style polymetallic lenses at and above the unconformity, with variable Ni, Co, As, and Pb contents and elevated amounts of Cu, Mo, Zn, Au, S, Pt, and REEs, to ingress-style near-monometallic basement-hosted vein sets, with low base metal and REE contents.