Database name: |
Uranium Deposits, Athabasca Basin |
Custodial agency: |
Geological Survey of Canada |
Compilers: |
Sunil S. Gandhi |
Release date: |
2007-03-02 |
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Deposit group name(s): |
McClean Lake Uranium Deposits (occurrence name); McClean Lake Project (mine name) |
Political location(s): |
Canada; Province or state: Saskatchewan; Nearest community: La Ronge (400 km N) |
NTS map data: |
064L05 (Cunning Bay) |
Deposit clan (type): |
Unconformity-associated |
Deposit (sub) types: |
Unconformity-associated - Proterozoic - clay-bound; the deposits are podiform, located along graphitic horizons in the basement at the sub-Athabasca Group unconformity; they are polymetallic and have clay alteration characteristic of this deposit-type; Reference: Wheatley, K.; Williamson, A.; Tourigny, G.; Wilson, S.; Breton, G., 2006: Geology of the McClean Lake/Sue Deposits; C, Section Athabasca Basin Uranium Deposits, In Abstracts Volume for the 2006 CIM Uranium Field Conference, September 11-12, Saskatoon; Uranium: Athabasca Deposits & Analogues, Edited by Quirt, D., Abstracts Volume, Canadian Institute of Mining and Metallurgy, Saskatoon Section, CIM Geological Society, 164 p., p. 1 - 16 |
Deposit group status: |
producer; Size category: medium; Status comments: The group includes McClean North (9 pods), South (2 pods), Sue A, B, C, D, E and Caribou deposits, in a triangular area 4 km to a side, pointing NE; Sue C mined during 1997-2001; Sue A started in 2005 |
Geologic province: |
Churchill - Hearne Craton |
Geologic subprovince: |
Wollaston Domain (Fold Belt) |
Geologic district: |
Eastern Athabasca Basin |
Deposit object located: |
deposit centre (surface proj.) |
Commodities: |
U; Ni; Co |
Geological ages: |
Late Paleoproterozoic - Early Mesoproterozoic (host rocks) Early Mesoproterozoic - Middle Mesoproterozoic (mineralization) |
Coincident features: |
fold(s) (Folding of the Paleoproterozoic Wollaston Group strata with domal uplift of the Archean basement during the Hudsonian thermotectonic event ca. 1850 Ma); Coincident feature name: Wollaston Fold Belt unconformity (Erosion and lateritic weathering before deposition of the Athabasca Group continental siliciclastic beds ca. 1670 Ma on basement with graphitic strata); Coincident feature name: Sub-Athabasca Group Unconformity |
Host rocks: |
(1) metamorphic; paragneiss; Component: mineralizationHost rock stratigraphy: | Wollaston supergroup |
(2) surficial; laterite (sub-Athabasca unconformity); Component: mineralizationHost rock stratigraphy: | Wollaston supergroup |
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Metallogenic signatures: |
U-Ni-Co-As |
Qualified comments: |
(Applies to: discovery and development) During 1968-'74 Gulf Minerals Canada Ltd., held the area of McClean deposit group under Permit 8, and conducted airborne radiometric survey and the reconnaissance and ground level surveys. Later In 1974 the permit was acquired by Canadian Occidental Petroleum Ltd. (CanOxy). A reconnaissance survey over it was flown in that year, and also claims were staked over 260 km sq area of the Wolly property, which was later split into the Wolly and McClean Lake properties. CanOxy operated the project till 1985, in partnership with Inco Ltd. starting from 1977. Initial exploration comprised geochemical and ground radiometric surveys, but in 1977 airborne magnetic and EM surveys were conducted over the property. The new surveys defined conductors, and led to interpretation of the domal structure in basement beneath the Athabasca Group strata, which are 160 m thick over the McClean deposits to the west and 75 m thick over the Sue deposits to the east. First significant indication of mineralization was found in 1978 along a conductor, which prompted emphasis on geophysical rather than geochemical or radiometric targets. This led to discoveries of McClean North deposits in 1979, McClean South deposits in 1980, Candy Lake zone in 1981 and the JEB deposit 10 km to the north in 1982. In 1985, Minatco entered into a joint venture with CanOxy and Inco to become operator of the project. Further exploration better defined McClean zones, and in 1988 the Sue A and B deposits were discovered, followed-up of their trend led to the discovery of Sue C and CQ in 1989, Sue D in 1990 and Sue E in 1991. In 1990 the CanOxy-Inco Joint Venture sold out to Minatco. In 1992 Denison Mines Ltd. exhanged with Minatco 70 % interest in Midwest Lake project for 22.5 % interest in the McClean Lake project. OURD Canada Ltd., a Denison partner obtained 7.5 % interest in McLean project. Then in 1993 Cogema Resources Inc., now Areva Resources Canada Inc., acquired the uranium assets of Minatco in Canada (held by TOTAL of France). The company continued exploration from 1994 on, and discovered the Caribou Zone in 2002. In 1995, construction of McLean Lake facilities began. JEB pit was mined during 1995-'97, the Sue C pit during 1997-'01. The mill began production in 1999. Sue A was mined in 2005. Stripping at the Sue E pit started in 2006.
(Applies to: reserve/resource descriptions) Resource data from Wheatley et al. (2006): McClean North + South: 13.0 million lbs U3O8 @ grade of 2.25 % U3O8 Sue A: 1.2 million lbs U3O8 @ grade of 1.90 % U3O8 Sue B: 1.5 million lbs U3O8 @ grade of 0.67 % U3O8 Sue C: 24.5 million lbs U3O8 @ grade of 4.50 % U3O8 Sue D: 4.0 million lbs U3O8 @ grade of 0.80 % U3O8 Sue E: 9.0 million lbs U3O8 @ grade of 0.90 % U3O8 Caribou: 2.7 million lbs U3O8 @ grade of 2.60 % U3O8
(Applies to: regional structure) Deposits of this group occur within a 5x5 km are at the boundary of the Wollaston and Mudjatik domains. The Wollaston Group here forms the 'Telegraph Lake synformal pericline' between elongate Archean basement domes, namely the Wollaston Lake dome to the southeast and the McLean Lake dome to the southwest, and the circular Torwalt Dome to the north. Three phases of Hudsonian deformation are recognized in the strata: the ductile D1 event of isoclinal to asymmetrical folding that resulted in east-trending, elongate overturned synforms; the ductile D2 event contorted the strata into a series of NE-trending tight isoclinal to asymmetrical overturned folds; and the D3 brittle event resulted in the wrapping of the strata around the Archean domes. Other brittle structures of different age and form occur in the crystalline basement, but none of these appear to be major dislocations and most appear to be pre-Athabasca Group in age. However, some may have been reactivated at the time of mineralization. The Athabasca sandstones also have a series of joint and fracture sets. These and the paleotopographic highs played part in fluid flow through the nearly horizontal beds. Superimposed on these pre-existing fractures, in the basement and the sandstone, are the structures associated with mineralization. Synchronous with early mineralization stage there appears to a dilational-extensional phase: the open spaced veins and fracures, the rotational block breccias, 'Rabbit Ears' mineralization, and disruption of conglomerate unit. This was followed by quartz-illite-siderite-hematite-pyrite infilling of the fractures. Later post-mineralization corrosion of fracture walls and breccia blocks and a resulting collapse led to widespread brecciation, slickensiding of illite clay - even on horizontal surfaces, and the brecciation of early formed ore. The late stage brecciation, which can be quite spectacular, caused permeability and allowed reactions to continue long after the primary events. |
Links to other databases: |
SMDI; Key value: 2529 |
References: |
Boudemont, D.; Piquard, J. P.; Ey, F.; Zimmerman, J., 1993 |
The Sue Uranium Deposits, Saskatchewan, Canada |
Exploration and Mining Geology, Volume 2, p. 179 - 202 |
Boudemont, D.; Pacquet, A., 1996 |
The Sue D and E Uranium Deposits, Northern Saskatchewan: Evidence for Structurally Controlled Fluid Circulation in the Athabasca Basin |
C, Section Uranium Deposit Studies and Exploration Techniques, In Advances in Saskatchewan Geology and Mineral Exploration: Proceedings of a Symposium held in Saskatoon, November 21 and 22, 1996 (MinExpo '96 Symposium), Edited by Ashton, K. E.; Harper, C. T., Special Publication, Saskatchewan Geological Society, Saskatchewan Geological Society, 14, 163 p., p. 85 - 94 |
Tremblay, L. P., 1982 |
Geology of the Uranium Deposits Related to the Sub-Athabasca Unconformity |
Paper, Geological Survey of Canada, Publication code 81-20, 56 p.. |
Wallis, R. H.; Saracoglu, N.; Brummer, J. J.; Golightly, J. P., 1883 |
Geology of the McClean Uranium Deposits |
Section Introductory Papers, In Uranium Exploration in Athabasca Basin, Edited by Cameron, E. M., Paper, Geological Survey of Canada, Geological Survey of Canada, 82-11, 310 p., 8 maps, p. 71 - 110 |
Wallis, R. H.; Saracoglu, N.; Brummer, J. J.; Golightly, J. P., 1985 |
The Geology of the McClean Uranium Deposits, Northern Saskatchewan |
Chapter 2, Section Unconformity-type Deposits in Saskatchewan, In Geology of Uranium Deposits, Edited by Sibbald, T. I. I.; Petruk, W., Special Volume, The Canadian Institute of Mining and Metallurgy, The Canadian Institute of Mining and Metallurgy, 32, 268 p., p. 101 - 131 |
Wallis, R. H.; Saracoglu, N.; Brummer, J. J.; Golightly, J. P., 1986 |
The Geology of the McClean Uranium Deposits, Northern Saskatchewan |
Chapter 4, Section Saskatchewan Unconformity-associated and Sedimentary-hosted Deposits of Helikian Age, In Uranium Deposits of Canada, Edited by Evans, E. L., Special Volume, The Canadian Institute of Mining and Metallurgy, The Canadian Institute of Mining and Metallurgy, 33, 323 p., p. 193 - 217 |
Wheatley, K.; Williamson, A.; Tourigny, G.; Wilson, S.; Breton, G., 2006 |
Geology of the McClean Lake/Sue Deposits |
C, Section Athabasca Basin Uranium Deposits, In Abstracts Volume for the 2006 CIM Uranium Field Conference, September 11-12, Saskatoon; Uranium: Athabasca Deposits & Analogues, Edited by Quirt, D., Abstracts Volume, Canadian Institute of Mining and Metallurgy, Saskatoon Section, CIM Geological Society, 164 p., p. 1 - 16 |
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Associated deposit(s): |
McClean Lake North Uranium Deposits (40012), McClean Lake South Uranium Deposits (40013), Sue Uranium Deposits (40014), Caribou Zone (40015) |