Deposit number | Country | Location | Names | Commodities |
798 | Canada (British Columbia) | 49.03.00 N -- 125.26.00 W | Brynnor | Fe |
Database name: | World Fe-oxide+/-Cu-Au-U (IOCG) deposits | ||||||||||||||||||||||||||||||||||||||||
Compilers: | Sunil S. Gandhi | ||||||||||||||||||||||||||||||||||||||||
Release date: | 2015-03-04 | ||||||||||||||||||||||||||||||||||||||||
Deposit name(s): | Brynnor | ||||||||||||||||||||||||||||||||||||||||
Political location(s): | Canada; Province or state: British Columbia; Nearest community: Ucluelet, Vancouver Island (14.5 km NE) | ||||||||||||||||||||||||||||||||||||||||
NTS map data: | 092F03 (Effingham River) | ||||||||||||||||||||||||||||||||||||||||
Deposit clan (type): | Iron Skarn-type | ||||||||||||||||||||||||||||||||||||||||
Deposit (sub) types: | massive lensoid magnetite body 500 m long; strike NNE; plunge to south; sharp boundaries with host limestone; some veins and disseminations near ore body; serpentine along post-ore faults and shears; 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. host strata were folded prior to mineralization into two synclines separated by an anticline, and the ore body is affected by later folding, faulting and shearing, marked by serpentine-lined fractures; 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: 4.5 Mt | ||||||||||||||||||||||||||||||||||||||||
Geologic province: | Cordilleran Orogen | ||||||||||||||||||||||||||||||||||||||||
Geologic subprovince: | Insular Belt | ||||||||||||||||||||||||||||||||||||||||
Geologic district: | Wrangell Terrane | ||||||||||||||||||||||||||||||||||||||||
Deposit object located: | open pit | ||||||||||||||||||||||||||||||||||||||||
Commodities: | Fe | ||||||||||||||||||||||||||||||||||||||||
Mineralization styles: | massive; veins; disseminations around massive bodies | ||||||||||||||||||||||||||||||||||||||||
Geological ages: | Late Triassic - Early Jurassic (host rocks) Early Jurassic (mineralization) | ||||||||||||||||||||||||||||||||||||||||
Tectonic setting: | continental marginal arc-fold belt; transpressive; Formal name: Bonanza Magmatic Arc (host rocks) | ||||||||||||||||||||||||||||||||||||||||
Coincident features: | limestone-andesite contact (north pod near surface has replaced limestone; it plunges southwest and meets ); Coincident feature name: Quatsino Formation folding (ore apparently localized in axial zone of a syncline); Coincident feature name: Kennedy Lake sequence | ||||||||||||||||||||||||||||||||||||||||
Regional tectonic structure: | folded host strata trending northeast (pre-ore folds, truncated by granodiritic stock, and post-ore deformation) Tectonic structure name: Quatsino Formation | ||||||||||||||||||||||||||||||||||||||||
Host rocks: | (1) sedimentary; carbonate (Late Triassic bedded limestone); Depositional setting: arc-back arc basin; Metamorphic grade: lower amphibolite
(2) volcanic; intermediate-felsic volcanic rocks (andesite intruive into limestone); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: lower amphibolite
(3) volcanic; intermediate volcanic rocks (Lower Jurassic andesitic tuffs and flows ); Depositional setting: arc-back arc basin; Metamorphic grade: lower amphibolite
(4) intrusive; granodiorite-tonalite-diorite suite (Early to Middle Jurassic pluton); Magma series/sedimentary package/metamorphic group: calc-alkaline; Depositional setting: arc-back arc basin; Metamorphic grade: none
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Related igneous rocks: | (1) intrusive; quartz monzonite-monzogabbro suite (early Jurassic; likely source of mineralization); Initials: Island Plutonic suite; Magma series: calc-alkaline; Depositional setting: hypabyssal
(2) intrusive; gabbro suite (small pre-ore dykes, serpentinized); Initials: Pre-ore dykes; Magma series: calc-alkaline; Depositional setting: hypabyssal
(3) intrusive; gabbro suite (small basic dykes, slightly serpentinized); Initials: Pre-ore mafic dykes; Magma series: calc-alkaline; Depositional setting: hypabyssal
(4) intrusive; gabbro-diorite suite (youngest dyke in the deposit area); Initials: Diabase dyke; Magma series: calc-alkaline
(5) intrusive; gabbro-diorite suite (post-ore dykes, up to 10 m wide); Initials: Leucodiorite dykes; Magma series: calc-alkaline; Depositional setting: hypabyssal
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Metallogenic signatures: | Fe | ||||||||||||||||||||||||||||||||||||||||
Alteration signatures: | skarn: garnet and diopside; What was altered: limestone and andesitic host rocks serpentinization: serpentine; What was altered: iron ore and andesitic intrusives epidotization: epidote; What was altered: mafic silicates chloritization: chlorite; What was altered: mafic silicates sericitization: sericite; What was altered: fledspar in andesitic rocks carbonatization: calcite, recrystallized; What was altered: limestone | ||||||||||||||||||||||||||||||||||||||||
Mineralogy: | (alteration): garnet, serpentine, epidote, chlorite, sericite (gangue): calcite (mineralization): magnetite, pyrite, pyrrhotite | ||||||||||||||||||||||||||||||||||||||||
Radiometric ages: | Object dated: Related igneous rocks(1); Age - Ma: 167; +10; -10; Dating method: K-Ar; Concentrate: biotite; Source rock: granodiorite; Formal name: Island Intrusion; Event dated: intrusive event; Interpretive comment: the radiometric age is consistent with the middle Jurassic age deduced from the geological relations; 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: | elongate plunging lens
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Qualified comments: | (Applies to: discovery and development) A strong magnetic anomaly reported in 1902; explored in 1960; open pit production during 1962- 1968 totalled 4,480,940 tonnes of ore from which 3,011,306 tonnes of Fe recovered; traces of Fe sulphides. 250 000 tonnes of limestone were gathered from the dumps and shipped in 1998. | ||||||||||||||||||||||||||||||||||||||||
Links to other databases: | BC MINFILE; Key value: 092F 001 | ||||||||||||||||||||||||||||||||||||||||
References: |
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