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): |
Klaanch; Nimpkish Iron |
Political location(s): |
Canada; Province or state: British Columbia; Nearest community: Port McNeil (25 km SSW) |
NTS map data: |
092L07 (Nimpkish) |
Deposit clan (type): |
Iron Skarn-type |
Deposit (sub) types: |
tabular ore body at boundary of Karmutsen volcanics and Quatsino limetone; contact with limestone is sharp; with the volcanics obscured by skarn; ore body narrows to the southeast and is vertical; Reference: Sangster, D. F., 1969: The Contact Metasomatic Magnetite deposits of Southwestern British Columbia; Bulletin, Geological Survey of Canada, Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa, Canada, Publication code 172, 85 p., 9 maps. magnetite ore with little skarn or other minerals, except for post-ore irregualr veins and pods of coarse calcite, which locally make up 50% of ore; they contain chalcopyrite, pyrite and sphalerite; Reference: Sangster, D. F., 1969: The Contact Metasomatic Magnetite deposits of Southwestern British Columbia; Bulletin, Geological Survey of Canada, Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa, Canada, Publication code 172, 85 p., 9 maps. |
Deposit status: |
past producer; Status comments: discovered in 1897; dip-needle survey in 1910; limited drilling in 1954; prduction from 1959 to 19...; |
Geologic province: |
Cordilleran Orogen |
Geologic subprovince: |
Insular Belt |
Geologic district: |
Wrangell Terrane |
Commodities: |
Fe |
Mineralization styles: |
massive; disseminated |
Geological ages: |
Late Triassic - Middle Jurassic (host rocks) Middle Jurassic (mineralization) Middle Jurassic (related magmatics) |
Tectonic setting: |
continental marginal arc-fold belt; transpressive; Formal name: Bonanza magmatic arc (mineralization) |
Coincident features: |
formational boundary (ore body has sharp contact with the Quatsino limestone to the southwest and diffused one to the northeast with volcanics obscured by skarn); Coincident feature name: Karmutsen-Quatsino boundary folding (near the southeast end of the ore body there is minor tight fold that has caused widening of the ore zone in the open pit); Coincident feature name: Ore zone fold fault trending northeast (a fault near south end dips steeply SE; it has 30 m dip-slip; a breccia zone along it is 1 to 1.5 m wide; fragments are slicken-sided); Coincident feature name: northeast faults |
Regional tectonic structure: |
contact zone of limestone, andesite and diorite-quartz monzonite intrusion (nearly vertical, northwest-trending zone of Karmutsen Formation, with Quatsino Formation to the west and Nimpkish intrusion to the east) Tectonic structure name: Nimpkish batholith margin |
Host rocks: |
(1) volcanic; intermediate volcanic rocks (intruded by dioritic phase of Nimpkish intrusion ); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: greenschistExternal host rock forms: | flows | Host rock protoliths: | andesite (fine grained, massive, black or dark grey, amygdaloidal flows) | Internal host rock structures: | fine grained, ophitic amygdaloidal | Individual lithologies: | andesite (plagiclase laths, interstitial biotite-hornblende; epidote, calcite, actinolite in amygdules; laumontite-calcite veins; scattered sulphide clusters) | Host rock stratigraphy: | Karmutsen Formation |
(2) sedimentary; carbonate (pure calcium carbonate, massive, recrystallized); Depositional setting: carbonate platform; Metamorphic grade: greenschistExternal host rock forms: | massive | Host rock protoliths: | limestone (pure limestone, massive; contains thin discontinuous dark bands that may be shaly layers); Host rock protolith name: Quatsino Formation of Vancouver Group | Internal host rock structures: | coarsely crystalline | Individual lithologies: | marble (bedding rare or absent; dark bands may be flow bands; they are undulatory, nearly horizontal, but are vertical near ore body parallel to contact) | Host rock stratigraphy: | Quatsino Formation of Vancouver Group |
(3) volcanic; intermediate volcanic rocks (flows, volcaniclastics, dykes and sills); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: greenschistHost rock protoliths: | andesites (early to mid-Jurassic pre-ore volcanics; overlie the Quatsino Formation; occur in and near the deposit); Host rock protolith name: Bonanza Group | Host rock stratigraphy: | Bonanza Group |
(4) intrusive; quartz monzonite-monzogabbro suite (outcrops extensively south of open pit); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: noneExternal host rock forms: | crystalline, coarse | Host rock protoliths: | quartz monzonite (one of the Island intrusions, mid- to late Jurassic in age; dioritic intrusion in volcanics at ore body regarded as a marginal phase of the batholith); Host rock protolith name: Nimpkish batholith | Internal host rock structures: | hypidiomorphic | Individual lithologies: | quartz monzonite (a phase of the larger hornblende and/or biotite granodiorite batholith, which is similar to other batholiths of northeastern Vancouver Island) | Host rock stratigraphy: | Nimpkish batholith |
(5) intrusive; quartz monzonite-monzogabbro suite (post-ore dykes; affected by post-ore faults); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: noneExternal host rock forms: | massive, porphyritic to equigranular | Host rock protoliths: | intermediate porphyry (occur as isolated bodies bound by faults; not affected by skarnification); Host rock protolith name: Feldspar porphyry dykes | Internal host rock structures: | porphyritic | Individual lithologies: | intermediate porphyry (sericitized plagioclase phenocrysts in sericitized and chloritized plagioclase laths in matrix; calcite, epidote and opacite as accessory minerals) | Host rock stratigraphy: | Feldspar porphyry dykes |
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Metallogenic signatures: |
Fe-Cu |
Alteration signatures: |
skarn: garnet and diopside; What was altered: andesitic host rocks carbonatization: irregular veins and pods of coarse calcite in magn; What was altered: ore zone chloritization: chlorite-rich matrix in breccia zone of post-ore f; What was altered: ore and wall rock |
Mineralogy: |
(alteration): garnet, diopside, epidote (mineralization): magnetite (vein mineralization): calcite, chalcopyrite, pyrite, sphalerite |
Radiometric ages: |
Object dated: Host Rocks(4); Age - Ma: 151; +14; -14; Dating method: K-Ar; Concentrate: biotite; Source rock: granodiorite; Formal name: Nimpkish batholith; Event dated: intrusive event; Interpretive comment: age is consistent with middle to late Jurassic geological age; slightly older than hornblende age; Reference: Carson, D. J. T., 1973: The Plutonic Rocks of Vancouver Island, British Columbia: Their Petrography, Chemistry, Age and Emplacement; Paper, Geological Survey of Canada, Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa, Canada, Publication code 72-44, 70 p.
Object dated: Host Rocks(4); Age - Ma: 143; +60; -60; Dating method: K-Ar; Concentrate: hornblende; Formal name: Nimpkish batholith; Event dated: intrusive event; Interpretive comment: age is younger and less reliable than the biotite age of 151 ± 14 Ma noted in Rank 1; Reference: Carson, D. J. T., 1973: The Plutonic Rocks of Vancouver Island, British Columbia: Their Petrography, Chemistry, Age and Emplacement; Paper, Geological Survey of Canada, Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa, Canada, Publication code 72-44, 70 p. |
Deposit shape: |
tabularDeposit dimensions: | length: 300 metres width: 60 metres depth: 150 metres |
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Qualified comments: |
(Applies to: discovery and development) Discovered in 1897; dip-needle survey in 1910; limited drilling in 1954; prduction from 1959 to 19...; |
Links to other databases: |
BC MINFILE; Key value: 092L 123 |
References: |
British Columbia Mines and Energy, 2001 |
British Columbia MINFILE Database |
Government of British Columbia, MINFILE Mineral Inventory, Internet |
Carson, D. J. T., 1973 |
The Plutonic Rocks of Vancouver Island, British Columbia: Their Petrography, Chemistry, Age and Emplacement |
Paper, Geological Survey of Canada, Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa, Canada, Publication code 72-44, 70 p. |
Eastwood, G. E. P., 1965 |
Replacement Magnetite on Vancouver Island, British Columbia |
Economic Geology, Volume 60, p. 124 - 148 |
Ettlinger, A. D.; Ray, G. E., 1990 |
Precious Metal Enriched Skarns in British Columbia: An Overview and Geological Study |
Paper, Geological Survey Branch, Mineral Resources Division, British Columbia Ministry of Energy, Mines and Petroleum Resources, Province of British Columbia, Canada, Publication code 1989-3, 128 p., 1 maps. |
Gross, G. A., 1996 |
Skarn Iron |
20. Skarn Deposits, Section 20.4 Skarn Iron, in Geology of Canadian Mineral Deposit Types, Edited by Eckstrand, O. R.; Sinclair, W. D.; Thorpe, R. I., Geology of Canada, Decade of North American Geology (DNAG), Geological Survey of Canada, Geological Society of America, Volume 8, 640 p, p. 489 - 495 |
Hoadley, J. W., 1953 |
Geology and Mineral Deposits of the Zeballos-Nimpkish Area, Vancouver Island, British Columbia |
Memoir, Geological Survey of Canada, Geological Survey of Canada, Publication code 272 |
Meinert, L. D., 1984 |
Mineralogy and Petrology of Iron Skarns in Western British Columbia, Canada |
Economic Geology, Volume 79, p. 869 - 882 |
Meinert, L. D., 1992 |
Skarns and Skarn Deposits |
Geoscience Canada, Volume 19, p. 145 - 162 |
Muller, J. E., 1977 |
Geology of Vancouver Island |
Open File Report, Geological Survey of Canada, Geological Survey of Canada, Publication code 463, 1 maps. |
Sangster, D. F., 1969 |
The Contact Metasomatic Magnetite deposits of Southwestern British Columbia |
Bulletin, Geological Survey of Canada, Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa, Canada, Publication code 172, 85 p., 9 maps. |
Southerland-Brown, A., 1966 |
Tectonic History of the Insular Belt of British Columbia |
in A Symposium on the Tectonic History and Mineral Deposits of the Western Cordillera in British Columbia and Neighbouring Parts of the United States, Edited by Anonymous, Special Volume, Geological Society, Canadian Institute of Mining and Metallurgy, Canadian Institute of Mining and Metallurgy, 8, 353 p, p. 83 - 100 |
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