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): |
Shamrock; Blackjack; Empire |
Political location(s): |
Canada; Province or state: British Columbia; Nearest community: Port McNeil (30 km SW) |
NTS map data: |
092L06 (Alice Lake) |
Deposit clan (type): |
Iron Skarn-type |
Deposit (sub) types: |
scattered outcrops of Bonanza rocks at margin of Coast copper stock host vugs carrying quartz and botryoidal magnetite, and nearby Quatsino limestone has some layers selectively replaced by magnetite; 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: |
unknown; Size category: very small; Status comments: prospect near open pits of Merry Widow, Kingfisher and Raven deposits |
Geologic province: |
Cordilleran Orogen |
Geologic subprovince: |
Insular Belt |
Geologic district: |
Wrangell Terrane |
Commodities: |
Fe |
Mineralization styles: |
selective replacement of carbonate layers; vuggy |
Geological ages: |
Late Triassic - Early Jurassic (host rocks) Early Jurassic - Middle Jurassic (mineralization) |
Tectonic setting: |
continental marginal arc-fold belt; transpressive; Formal name: Bonanza magmatic arc (mineralization) |
Coincident features: |
intrusive contact (scattered outcrops of limestone and of Bonanza volcanic rocks host magnetite and botryoidal magnetite, respectively ); Coincident feature name: Quatsino limestone-Coast Copper stock |
Regional tectonic structure: |
wedge of host volcanic rock between limestone and intrusion (margin of intrusion dips 45° west, and limestone beds dip vertical or toward the intrusion) Tectonic structure name: Coast Copper stock margin |
Host rocks: |
(1) sedimentary; carbonate (Late Triassic, well-bedded, gently dipping to west); Magma series/sedimentary package/metamorphic group: carbonate; Depositional setting: arc-back arc basin; Metamorphic grade: lower amphiboliteHost rock protoliths: | limestone (gently folded; recrystallized near Coast Copper stock with destruction of bedding features); Host rock protolith name: Quatsino Formation of Vancouver Group | Host rock stratigraphy: | Quatsino Formation of Vancouver Group |
(2) volcanic; mafic-intermediate volcanic rocks (Early Jurassic; small outcrops); 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-basalt (volcanic and volcaniclastic rocks; located between Coast Coper stock and Quatsino limestone); Host rock protolith name: Bonanza Group | Internal host rock structures: | fine grained to porphyritic | Individual lithologies: | basalt-andesite (variable in composition; hornfelsed and skarnified near Coast Copper pluton) | Host rock stratigraphy: | Bonanza Group |
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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: |
Fe |
Alteration signatures: |
skarn: garnet and diopside; What was altered: volcanic host rocks |
Mineralogy: |
(gangue): quartz (mineralization): magnetite, magnetite, botryoidal |
Deposit shape: |
irregular - veins |
Links to other databases: |
BC MINFILE; Key value: 092L 040 |
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 |
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 |
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. |
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