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): |
Old Sport; Coast Copper |
Political location(s): |
Canada; Province or state: British Columbia; Nearest community: Port McNeil (32 km SW) |
NTS map data: |
092L06 (Alice Lake) |
Deposit clan (type): |
Iron Skarn-type |
Deposit (sub) types: |
most of the ore is stratiform along thin limestone between underlying andesite and an interbedded flow within Quatsino limestone; the ore and skarn are strikingly banded; bands are 0.5 to 2.5 cm thick; 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. possible Cu-rich member of Fe-Cu skarn zonation in Benson Lake district; deposit rich in chalcopyrite and pyrrhotite; contains fibrous magnetite after hematite; may be Cloncurry-type; Reference: 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. |
Deposit status: |
past producer; Size category: 2.6 Mt |
Geologic province: |
Cordilleran Orogen |
Geologic subprovince: |
Insular Belt |
Geologic district: |
Wrangell Terrane |
Deposit object located: |
open pit |
Commodities: |
Cu; Au; Ag; Fe |
Mineralization styles: |
stratiform; replacement of carbonate matrix ; disseminated |
Geological ages: |
Late Triassic - Early Jurassic (host rocks) Middle Jurassic (related magmatics) Middle Jurassic (mineralization) |
Tectonic setting: |
continental marginal arc-fold belt; transpressive; Formal name: Bonanza magmatic arc (mineralization) |
Coincident features: |
carbonate horizon (host carbonate unit between flows at the boundary of Karmutsen and Quatsino formations); Coincident feature name: Old Sport horizon bedding in host strata (banding in ore is parallel to the host strata; indicative of replacement of favourable beds); Coincident feature name: Old Sport horizon |
Regional tectonic structure: |
broad open syncline, plunging southwest toward a monzogabbro intrusive (the Coast Copper stock intruded at the nose of the syncline; the Old Sport horizon dips 35° southwest toward the intrusive contact, which dips 70° out) Tectonic structure name: Coast Copper stock margin |
Host rocks: |
(1) volcanic; intermediate volcanic rocks (Flows and tuffs); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: greenschistExternal host rock forms: | massive, porphyritic to equigranular | Host rock protoliths: | andesite; Host rock protolith name: Karmutsen Formation of Vancouver Group | Internal host rock structures: | fine grained to porphyritic | Individual lithologies: | andesite (altered andesite near the ore body contains chlorite, albite, sericite and albite) | Host rock stratigraphy: | Karmutsen Formation of Vancouver Group |
(2) sedimentary; carbonate (thin ore-bearing 'Old Sport' interflow horizon near top of volcanics); Depositional setting: arc-back arc basin; Metamorphic grade: greenschistExternal host rock forms: | well bedded | Host rock protoliths: | carbonate (located at boundary of Karmutsen and Quatsino formations, which is locally referred to as 'Old Sport' horizon); Host rock protolith name: Old Sport horizon | Internal host rock structures: | banding | Individual lithologies: | skarn (ore and skarn are strikingly well banded at several places; pods of calcite may be remnants of original limestone) | Host rock stratigraphy: | Karmutsen Formation |
(3) volcanic; intermediate volcanic rocks (tabular body of fine grained volcanic rock); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: greenschistHost rock protoliths: | andesites (uppermost flow of Karmutsen Formation or interbedded lava flow near the base of Quatsino Formation); Host rock protolith name: Karmutsen Formation of Vancouver Group | Host rock stratigraphy: | Karmutsen Formation |
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Related igneous rocks: |
(1) intrusive; quartz monzonite-monzogabbro suite (Early to Middle Jurassic Island Plutonic Suite); Initials: Coast Copper or Benson Lake stock ; Magma series: calc-alkaline; Depositional setting: hypabyssalIndividual lithologies: | gabbro-diorite-quartz monzonite (eastern part of the stock near iron deposits is gabbroic, the western part is quartz monzonitic) |
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Metallogenic signatures: |
Cu-Au-Ag-Fe |
Alteration signatures: |
skarn: garnet, epidote, calcite; What was altered: host limestone and adjacent volcanic rocks chloritization: chlorite; What was altered: volcanic rocks albitization: albite; What was altered: volcanic rocks sericitization: sericite; What was altered: feldspar in volcanic rocks carbonatization: coarse calcite pods and irregular veins carrying s; What was altered: ore body |
Mineralogy: |
(alteration): garnet, pyroxene, amphibole, epidote (gangue): calcite (mineralization): chalcopyrite, pyrrhotite, magnetite, hematite |
Radiometric ages: |
Object dated: Alteration Signature; Age - Ma: 179.5; +8; -8; Dating method: K-Ar; Concentrate: phlogopite; Source rock: skarn; Formal name: skarnification; Event dated: contact metasomatism; Interpretive comment: skarn related to Coast Copper stock at Merry Widow deposit 3 km to SE; 2 runs: 181 and 178 Ma; 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: |
tabular |
Qualified comments: |
(Applies to: discovery and development) Deposit was originally exploited for its copper content, which averaged 2 %; magnetite recovered in milling was later shipped; deposit averaged 15 % Fe; contained notable amounts of Au, Ag, Co and Zn; production: 2657593 tonnes of ore, 3869 kg Au, 11731 kg Ag, 41 193 t Cu and unknown t Fe;
(Applies to: location and access) Near Merry Widow Mine |
Links to other databases: |
BC MINFILE; Key value: 092L 035 |
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 |
Hudson, R., 1997 |
A Field Guide to Gold, Gemstones and Mineral Sites of British Columbia, Volume I, Vancouver Island |
Orca Book Publishers, PO Box 5626, Station B, Victoria, British Columbia, Canada, 214 p. |
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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