Database name: |
World Fe-oxide+/-Cu-Au-U (IOCG) deposits |
Compilers: |
Sunil S. Gandhi |
Release date: |
2015-03-04 |
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Deposit name(s): |
Jackpot; Jackpot Claim Group; JEN Claim Group (JEN1-15); U Claim Group (U1-20) |
Political location(s): |
Canada; Province or state: Northwest Territories; Nearest community: Yellowknife (380 km NNW) Canada; Province or state: Northwest Territories; Nearest community: Port Radium / Great Bear Lake (65 km E) |
NTS map data: |
086F09 (Bishop Lake) |
Deposit clan (type): |
Cloncurry-type |
Deposit (sub) types: |
subparallel lensoid zones ; Uraninite and chalcopyrite in magnetite-rich lenses and pods, up to15 m long, in biotitic granitoid paragneiss; U-Th ratio up to 1; Ag and rare earths present; some magnetite-apatite-actinolite veins; Reference: McGlynn, J. C., 1971: Metallic Mineral Industry, District of Mackenzie; Paper, Geological Survey of Canada, Publication code 70-17, 194 p. |
Deposit status: |
prospect; Size category: very small |
Geologic province: |
Wopmay Orogen |
Geologic subprovince: |
Great Bear Magmatic Zone |
Geologic district: |
Northern Wopmay Fault Zone |
Deposit object located: |
shaft |
Commodities: |
U; Cu; Fe; REE |
Mineralization styles: |
stratiform magnetite-rich lenses in paragneiss; paragenetically younger sulphides and uraninite |
Geological ages: |
Middle Paleoproterozoic (host rocks) Middle Paleoproterozoic (mineralization) |
Tectonic setting: |
continental marginal deformation zone-major fault zone; convergent; Formal name: Wopmay Faut (or Medial) Zone (host rocks) continental marginal deformation zone-major fault zone; convergent; Formal name: Hottah Terrane-Slave Craton Collision Zone (country rocks) |
Coincident features: |
lenses and pods in layered gneisses (metasedimentary remnant of the Paleoproterozoic Hottah terrane near the west boundary of the Wopmay fault zone); Coincident feature name: Treasure Lake Group lenses and pods in layered gneisses (15 m wide zone trends northerly; variable steep dips; local minor folds and crenulations in the magnetite-biotite-rich paragneiss); Coincident feature name: Treasure Lake Group |
Regional tectonic structure: |
general north trend parallel to Wopmay Fault Zone (a remnant of metasedimentary strata in the Paleoproterozoic Hotah terrane that collided with the Slave craton to the east ca. 1883 Ma) Tectonic structure name: Treasure Lake Group |
Host rocks: |
(1) metamorphic; paragneiss (biotite-rich granitoid paragneisses); Depositional setting: continental; Metamorphic grade: amphiboliteExternal host rock forms: | gneissic | Host rock protoliths: | iron-rich siltstone (possibly magnetite-rich placer or iron-rich tuffaceous siltstones); Host rock protolith name: Treasure Lake Group | Internal host rock structures: | foliated to layered; crenulated | Individual lithologies: | biotitic quartzo-feldspathic gneiss (varies from massive granitic to layered gneisses; bedding and lamination seen in thin sections; locally garnet and cordierite) | Host rock stratigraphy: | Treasure Lake Group |
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Related igneous rocks: |
(1) intrusive; granite suite (gradational boundary with paragneiss); Initials: Porphyritic granite; Magma series: calc-alkaline; Depositional setting: continentalIndividual lithologies: | potassic granite (perthitic microcline phenocrysts in matrix of quartz, plagioclase, biotite and opaque minerals) |
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Country rocks: |
(1) paragneiss; (grades into granitic gneiss); Country rock name: Treasure Lake Group; Metamorphic grade: amphiboliteCountry rock protoliths: | iron-rich siltstones (possibly magnetite-rich placer or iron-rich tuffaceous siltstones); Country rock protolith name: Treasure Lake Group | Individual lithologies: | biotitic quartzo-feldspathic gneiss (zone of granitized metasedimentary rocks 3 x 1.5 km; grades into granitic gneiss; trend NNE) |
(2) felsic volcanic assemblage; (unconformably overlying paragneisses); Country rock name: Sloan Group ; Metamorphic grade: noneCountry rock protoliths: | felsic volcanics (extrusives of the Great Bear magmatic zone ca. 1875-1865 Ma old); Country rock protolith name: Sloan Group | Individual lithologies: | dacite-rhyolite (volcanic textures preserved) |
(3) granite; (grades into paragneiss); Country rock name: porphyritic granite; Metamorphic grade: noneCountry rock protoliths: | granite (no sharp boundaries with the paragneiss ); Country rock protolith name: porphyritic granite | Individual lithologies: | granite (perthitic microcline phenocrysts 35%, 20 % plagioclase, close to 40% quartz, 5% green biotite, accessory opaque minerals) |
(4) diabase; (intrusive sheet dipping gently to south); Country rock name: Hottah diabase sheet; Metamorphic grade: noneCountry rock protoliths: | diabase (ENE-trending sheets dated at 780 Ma; one covers the area north of mineralized paragneiss of the Jackpot showing); Country rock protolith name: Hottah diabase sheet |
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Metallogenic signatures: |
Fe-U-Th-Cu-Ag-REE |
Alteration signatures: |
tourmalinization: tourmaline, schorl; What was altered: host mafic paragneiss hematization: hematite after primary magnetite; What was altered: magnetite |
Mineralogy: |
(alteration): hematite (gangue): quartz (mineralization): magnetite, uraninite, zircon, allanite, xenotime, apatite, pyrite, chalcopyrite, tourmaline, fluorite, ilmenite, pseudobrookite, galena |
Radiometric ages: |
Object dated: Mineralogy(2); Age - Ma: 1,872; +8; -8; Dating method: U-Pb; Concentrate: uraninite; Source rock: magnetite-rich paragneiss; Formal name: redistribution of syngenetic uranium; Event dated: mineralization; Interpretive comment: mineralization interpreted by Miller (1982) as slightly older than the Great Bear magmatic activity; Reference: Miller, R. G., 1982: The Geochronology of Uranium Deposits in the Great Bear Batholith, Northwest Territories; Canadian Journal of Earth Sciences, Volume 19, p. 1428 - 1448
Object dated: Mineralogy(2); Age - Ma: 1,849; +10; -10; Dating method: U-Pb; Concentrate: uraninite; Source rock: magnetite-rich paragneiss; Event dated: mineralization; Interpretive comment: this age may reflect resetting of isotopic equilibrium in the mineralization dated at 1872 ± 8 Ma; Reference: Miller, R. G., 1982: The Geochronology of Uranium Deposits in the Great Bear Batholith, Northwest Territories; Canadian Journal of Earth Sciences, Volume 19, p. 1428 - 1448 |
Deposit shape: |
lensoidDeposit dimensions: | strike length: 15 metres width: 2 metres length down-dip: 10 metres |
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Qualified comments: |
(Applies to: discovery and development) First staked in 1953; 3 mineralized zones about 1 km apart; drilling on the main zone to the north in 1954-'55 totalled 810 m in 16 holes; best assay: 0.17% U over 0.6 m; a 10 m inclined shaft in 1957; surface exploration intermittentlly after 1950s; airborne magnetic anomaly is 1000 nT; ground magnetic relief is 6000 nT; main anomaly about 1 km long; trends SSE; coincident spectrometric anomalies; second zone 1 km to the SSW; a trench sampled in 1972 ran 1.4% Cu and 6 g/t Ag over 6 m; a third radioactive zone is located 1 km east of the second zone and is relatively little explored |
References: |
Gandhi, S. S., 1992 |
Magnetite Deposits in Metasiltstones of the Snare Group at Hump Lake, Northwest Territories |
in Current Research 1992, Part A, Edited by Geological Survey of Canada, Paper, Geological Survey of Canada, 92-1A, p. 225 - 235 |
Gandhi, S. S., 1994 |
Geological Setting and Genetic Aspects of Mineral Occurrences in the Southern Great Bear Magmatic Zone, Northwest Territories |
in Studies of Rare-Metal Deposits in the Northwest Territories, Edited by Sinclair, W. D.; Richardson, D. G., Bulletin, Geological Survey of Canada, 475, 96 p, p. 63 - 96 |
McGlynn, J. C., 1971 |
Metallic Mineral Industry, District of Mackenzie |
Paper, Geological Survey of Canada, Publication code 70-17, 194 p. |
Miller, R. G., 1982 |
The Metallogeny of Uranium in the Great Bear Batholith Complex, Northwest Territories |
Ph. D. Thesis, University of Alberta, Edmonton, Alberta, University of Alberta, Edmonton, Alberta, 271 p. |
Miller, R. G., 1982 |
The Geochronology of Uranium Deposits in the Great Bear Batholith, Northwest Territories |
Canadian Journal of Earth Sciences, Volume 19, p. 1428 - 1448 |
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