EXTECH IV ATHABASCA URANIUM DEPOSIT DATABASE
Geological Survey of Canada, Saskatchewan Industry and Resources, and Alberta Geological Survey


DEPNO COUNTRY LOCATION ALLNAMES COMMODITIES
40029 Canada (Saskatchewan) 58.22.23 N -- 109.29.24 W N Deposit; Cluff Lake N Uranium Deposit U

Database name: Uranium Deposits, Athabasca Basin
Custodial agency: Geological Survey of Canada
Compilers: Sunil S. Gandhi
Release date: 2007-03-02
   
Deposit name(s): N Deposit (occurrence name); Cluff Lake N Uranium Deposit (occurrence name)
Political location(s): Canada; Province or state: Saskatchewan; Nearest community: Cluff Lake Mine-Mill Complex (2.5 km ENE)
NTS map data: 074K06 (Jolley Lake)
Deposit clan (type): Unconformity-associated
Deposit (sub) types: Unconformity-associated - Proterozoic - fracture-bound; veins and breccia-fillings in paragneisses near the unconformity with basal Athabasca siliciclastic sediments, with characteristic alteration; Reference: Lainé, R. T., 1986: Uranium Deposits of the Carswell Structure; 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. 155 - 169
Deposit status: advanced prospect; Size category: medium; Status comments: Reported measured resources in the N deposit, located 2.5 km northeast of Cluff Lake, are 505000 tonnes averaging 0.34 % U as of 1984 (Lainé, 19886)
Geologic province: Churchill - Rae Craton
Geologic subprovince: Taltson-Thelon Magmatic Zone
Geologic district: Western Athabasca Basin / Carswell Impact Crater
Deposit object located: drill hole
Commodities: U
Mineralization styles: veins and stringers (mineralization zone); shear zone(s) (mineralization zone); aggregates in quartz vein (mineralization zone); impact crater breccia-hosted (mineralization zone)
Geological ages: Middle Paleoproterozoic - Late Paleoproterozoic (host rocks)
Middle Mesoproterozoic - Late Mesoproterozoic (mineralization)
Tectonic setting: continental marginal basement thrust faults-intracratonic; multiple regimes; Formal name: Earl River Gneiss and Granitoids (host rocks)
Coincident features: fracture(s) (mainly an outcropping set of N-S fractures with a 40° dip to the west; a 040° fault dipping 60° to the NW and 135-150° fractures parallel to foliation); Coincident feature name: North-South Fault Zone
fault(s) (the 040° fault zone has dextral movement, and hosts uranium veins over a 200 m length from 50 to 150 m depth; it is filled with bleached fault gauge); Coincident feature name: Northeast Fault
fault reactivation by meteorite impact (the Cluff breccia formed by post-impact relaxation were injected into the structure; later uranium was redistributed into veinlets and disseminations); Coincident feature name: Carswell meteorite crater
Regional tectonic structure: thrust fault (the subvertical fault separates a dome of the Earl River Gneiss from the younger Peter River Gneiss to the east; their boundary is locally mylonitized) Tectonic structure name: North-South Fault
uplift of core of meteorite crater (a meteorite impact ca. 450 Ma caused the 39 km diameter structure, a post-impact 1 km uplift of the basement core, faults and dyke-like Cluff breccias) Tectonic structure name: Carswell circular structure
Host rocks: (1) metamorphic; orthogneiss-paragneiss (highly altered mixed quartzofeldspathic gneiss and granitoids thrust eastward on Peter River gneiss); Depositional setting: mesozonal; Metamorphic grade: amphibolite - upper; Component: mineralization zone
External host rock forms:gneissic
Host rock protoliths:arkose (mainly meta-arkosic and some more mafic rocks, in part granitized and intruded by granitoid plutons ); Host rock protolith name: Unnamed
Internal host rock structures:foliated
Individual lithologies:arkose (a part of the gneissic complex dervied mainly from mafic volcanic and plutonic rocks)
Host rock stratigraphy:Earl River Metamorphic Suite

(2) metamorphic; paragneiss (metapelitic gneiss on the east side of the deposit; drilling shows that it overlies the Earl River Gneiss); Depositional setting: platform-shelf; Metamorphic grade: amphibolite (upper) - granulite; Component: basement
External host rock forms:unknown
Host rock protoliths:psammite-pelite (metapelitic and meta-arkosic gneisses on east side of the deposit; layering inherited from bedding); Host rock protolith name: Peter River Gneiss
Internal host rock structures:banding
Individual lithologies:metasediment (layered metapelitic and meta-arkosic gneisses on east side of the deposit; layering inherited from bedding)
Host rock stratigraphy:Peter River Metamorphic Suite
Metallogenic signatures: U-Bi-Mo-Se-Au-Ti-Cu-Pb
Alteration signatures: lateritic alteration: illite-kaolinite; What was altered: sub-Athabasca basement
illite alteration: illite; What was altered: host rocks of mineralized veins
chlorite alteration: chlorite; What was altered: host rocks of mineralized veins
sericitization: sericite; What was altered: host rocks of mineralized veins
silicification: quartz, replacive and open space fillings; What was altered: host fractures
Mineralogy: (alteration - undifferentiated / mineralization zone): quartz, hematite
(alteration - undifferentiated / alteration halo): thucolite, sericite, secondary U minerals, uranophane, ilsemannite
(alteration - wall rock / alteration halo): illite, chlorite - Mg-rich, organic matter
(mineralization - vein / mineralization zone): uraninite - ribboned, brannerite, pitchblende, coffinite, marcasite, chalcopyrite, covellite, galena, clausthalite
(mineralization - vein / alteration halo): jordisite
(mineralization - vein / mineralization zone): selenide, gold
(vein mineralization / mineralization zone): pyrite
Radiometric ages: Object dated: Mineralogy(1); Age - Ma: 1,180; Dating method: U-Pb; Concentrate: uraninite; Source rock: uranium ore (high grade); Formal name: vein mineralization; Event dated: mineralization (early); Interpretive comment: one of the oldest ages obtained from the uranium deposits of the Carswell structure; Reference: Lainé, R. T., 1986: Uranium Deposits of the Carswell Structure; 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. 155 - 169
Deposit shape: lensoid
Deposit dimensions:length: 1,200 metre
width: 250 metre
thickness: 90 metre
Qualified comments: (Applies to: discovery and development) Intensive exploration in the Cluff Lake area followed the 1967 airborne radiometric survey. In 1969 a scintillometer survey was carried out that outlined anomalies in more detail. Ground follow-up led to pitchblende boulders and their distribution was studied. Radon survey was conducted in the boulder region but no anomalies were found. Bedrock mineralization was however located in a brecciated zone in the basement rocks approximately 2.5 km ENE of the north end of Cluff Lake, and about 1.5 km NE of the D deposit. It was explored by 5 Winkie drill holes, two of which intersected mineralization. Further work in 1970 included resistivity survey in the N deposit area, which revealed a resistant plug. Several trenches blasted in the area exposed mineralized bedrock. This was tested with diamond drilling in 41 holes totalling 13142 feet (4007 m). Additional drilling to assess resources in the deposit was carried out in 1976. It included 7625 feet (2324 m) of diamond drilling and 610 feet (186 m) of percussion drilling. In 1985 Amok Limited released a revised reserves estimate.

(Applies to: mineralization) Mineralization is localized in faults, fractures and shear zones in Paleoproterozoic granitoid rocks intrusive into the Earl River and Peter River gneisses. They occur just west of a N-S fault that separates the Earl River complex dome to the west from the Peter River gneiss to the east. There are two mineralized structures: an outcropping set of N-S fractures dipping 40° W in a zone 160x20x60 m, and a N40°E mineralized breccia zone dipping 60° to the NW and more than 200 m long at depth between 50 and 100 m (Lainé, 1986, p. 165). Wall rock alteration is very intense throughout the mineralized zone. The host rocks are essentially pale green with replacement of feldspar by sericite and of ferromagnesium minerals by Mg-rich chlorite and sericite (Pacquet, 1983). Chlorite replaces illite. Close to mineralization the original rock textures are obliterated by alteration. Three main uranium assemblages have been recognized (Reyx, 1983; Ruhlmann, 1983): (i) ribboned uraninite with titanium minerals, Cu, Pb and Mo sulphides, and minor selenides, (ii) pitchblende with hematite, and (iii) late disseminations of coffinite. Organic matter, where present, is at the core of the veins. Similar but lower grade mineralization is also seen in the R showing, about 500 m to the east-southeast

(Applies to: discovery and development) The N, R and F zones are in an area 1500 x 600 m, located 2.5 km NE of the north end of Cluff Lake. This area was explored in 1969 by trenching the overburden that led to mineralized boulders and bedrock. During 1970-1973 detailed geochemical and geophysical surveys, and drilling of 700 holes at 20 m interval along lines 25 and 50 m apart, outlined the N deposit and smaller R and F zones to its SE and S. No mining or development work were undertaken.

(Applies to: reserve/resource descriptions) Estimated reserves announced in 1985: 505000 t of ore averaging 0.34 % U, or the resources of 1729 t of uranium.
Links to other databases: SMDI; Key value: 1173a
References:
Harper, C. T., 1983
The Geology and Uranium Deposits of the Central Part of the Carswell Structure, Northern Saskatchewan, Canada
Ph. D. Thesis, Colorado School of Mines, Golden, Colorado, U.S.A., 337 p..

Koning, E., 2006
The Cluff Lake Deposits, West Athabasca Basin, Saskatchewan, Canada
In Field Trip 3: Cluff Lake and Shea Creek Deposits; September 13-14; 2006 CIM Field Conference; Uranium: Athabasca Deposits and Analogues, Edited by Koning, E.; Robbins, J.; Carroll, J., Field Trip Guidebook, Canadian Institute of Mining and Metallurgy, CIM Geogolical Society, Saskatoon Section, 48 p., p. 1 - 32

Lainé, R. T., 1986
Uranium Deposits of the Carswell Structure
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. 155 - 169

Pacquet, A., 1983
Zone N, R, F, Rapport Pétrographique
Internal Report, Amok Ltd., formerly Mokta Ltd. (consortium of COGEMA, Mokta and Pechiney of France)

Reyx, J., 1983
Zone N, R, F, Rapport Metallogénie
Internal Report, Amok Ltd., formerly Mokta Ltd. (consortium of COGEMA, Mokta and Pechiney of France)

Ruhlmann, F., 1983
Zone N Rapport Metallogénie
Internal Report, Amok Ltd., formerly Mokta Ltd. (consortium of COGEMA, Mokta and Pechiney of France)

Saskatchewan Geological Survey, 2003
Geology, and Mineral and Petroleum Resources of Saskatchewan
Miscellaneous Report, Saskatchewan Industry and Resources, Publication code 2003-7, 173 p., 4 maps.

Saskatchewan Industry and Resources, 2001
Saskatchewan Mineral Deposits Index
Government of Saskatchewan, Geological Atlas of Saskatchewan, Internet

Tona, F.; Alonso, D.; Svab, M., 1985
Geology and Mineralization in the Carswell Structure - A General Approach
In The Carswell Structure Uranium Deposits, Saskatchewan, Edited by Lainé, R.; Alonso, D.; Svab, M., Special Paper, Geological Association of Canada, Geological Association of Canada, 29, 230 p., p. 1 - 18

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..

Resource data:
Disclaimer - Reserves/Resource Data

Her Majesty the Queen in Right of Canada, represented by the Minister of Natural Resources (NRCan) does not warrant or guarantee the accuracy, completeness or fitness for any purpose of Reserve and Resource information (Data) contained in this database, including whether the Data is compliant with any securities regulations or standards, and NRCan does not assume any liability with respect to any damage or loss incurred as a result of the use made of the Data.

Resource and reserve figures are historical in nature. The Data source provided with each set of figures should be cited if the Data are re-reported.

Estimate date: 1985; 0.505 million metric tons ore; Combined with production?: no; Provisional entry?: no; Resource category: Estimated Additional
Grade-commodity information:U: 0.3424 percent
weight-commodity information:U: 1,729 metric ton
Reference: Lainé, R.; Alonso, D.; Svab, M. (Editor(s)), 1985: The Carswell Structure Uranium Deposits, Saskatchewan; Special Paper, Geological Association of Canada, Geological Association of Canada, 29, 230 p..
Percent weights allocated to deposit: 100.0%
Associated group(s): Cluff Lake deposits (40002)

Generated 2007-03-02 2:36:36 PM with GQuery -- 3.7 ADO (3.19/3.20/3.21 -- 2006-02-24)
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