CANADIAN AND WORLD MINERAL DEPOSIT DATABASES
Geological Survey of Canada


Deposit number Country Location Names Commodities
776 Canada (British Columbia) 50.21.20 N -- 127.15.07 W Merry Widow; Empire Fe
 
Database name: World Fe-oxide+/-Cu-Au-U (IOCG) deposits
Compilers: Sunil S. Gandhi
Release date: 2015-03-04
   
Deposit name(s): Merry Widow; 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: stacked lenses hosted mainly by andesite near limestone; located just above the intrusive contact of Coast Copper or Benson Lake stock, which dips 55° to the east; ore lenses parallel to the contact; 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; Size category: 3 Mt
Geologic province: Cordilleran Orogen
Geologic subprovince: Insular Belt
Geologic district: Wrangell Terrane
Deposit object located: open pit
Commodities: Fe
Mineralization styles: stacked lenses; marginal disseminations
Geological ages: Late Triassic - Early Jurassic (country rocks)
Early Jurassic - Middle Jurassic (mineralization)
Tectonic setting: continental marginal arc-fold belt; transpressive; Formal name: Bonanza magmatic arc (mineralization)
Coincident features: intrusive contact (ore lenses parallel to the intrusive contact and discordant to the host strata); Coincident feature name: Coast Copper stock
northeast-trending faults (faults dip steeply to the south; displacement of a few metres; Merry Widow and Kingfisher deposits on the Kingfisher fault); Coincident feature name: northeast faults
Regional tectonic structure: broad open syncline, plunging southwest toward a monzogabbro intrusive (near deposit the strata and the intrusive contact trend north; the former dip west and the latter dips east) 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: shallow marine; Metamorphic grade: lower amphibolite
External host rock forms:well bedded
Host rock protoliths:limestone (gently folded; recrystallized near Coast Copper stock with destruction of bedding features); Host rock protolith name: Quatsino Formation of Vancouver Group
Internal host rock structures:fine grained
Individual lithologies:limestone (white to grey, high in calcium grading 52 to 54 % CaO and less than 2.5 % MgO)
Host rock stratigraphy:Quatsino Formation of Vancouver Group

(2) intrusive; gabbro-diorite suite (subvolcanic dykes and small bodies); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: hypabyssal; Metamorphic grade: lower amphibolite
External host rock forms:massive
Host rock protoliths:andesite-basalt (dykes, sills and irregular small intrusives; equivalents of Bonanza Group volcanics overlying Quatsino Formation); Host rock protolith name: Greenstone
Internal host rock structures:fine grained to porphyritic
Individual lithologies:basalt-andesite (variable in composition; hornfelsed and skarnified; pre-ore)
Host rock stratigraphy:Bonanza Group equivalents

(3) volcanic; unclassified volcanic rocks; Metamorphic grade: greenschist
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: hypabyssal
Individual lithologies:gabbro-diorite-quartz monzonite (eastern part of the stock near iron deposits is gabbroic, the western part is quartz monzonitic)

(2) intrusive; granite/tonalite-gabbro suite (post-ore dykes of diabase, alaskite and granodiorite); Initials: Post-ore dykes; Magma series: calc-alkaline; Depositional setting: hypabyssal
Individual lithologies:diabasic and granitic (age of various dykes not certain)
Metallogenic signatures: Fe-Cu-Au-Ag-Co-Zn
Alteration signatures: skarn: dioside, garnet, phlogopite; What was altered: limestone and volcanic rocks
Mineralogy: (alteration): cuprite, erythrite
(gangue): calcite
(mineralization): magnetite, arsenopyrite, pyrite, marcasite, pyrrhotite, chalcopyrite, cobaltite, sphalerite
Radiometric ages: Object dated: Alteration Signature(1); 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; 2 runs: 181 and 178 Ma; oldest age for the Island intrusions; 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: stacked lenses
Deposit dimensions:long axis: 225 metres
width: 100 metres
depth: 200 metres
Qualified comments: (Applies to: discovery and development) Magnetite in the area known since late 1890s; explored in 1950s; combined production from Merry Widow and nearby Kingfisher and Raven mines during 1957-1967 totalled 3,371,015 t ore averaging 58 % Fe
Links to other databases: BC MINFILE; Key value: 092L 044
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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