Occurrence Details


Occurrence Number:
105N 003
Occurrence Name:
Plata
Occurrence Type:
Hard-rock
Status:
Deposit
Date printed:
4/26/2025 1:34:28 PM

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General Information
Capsule
Work History
Assessment Reports
References
Resource / Reserve
Production
Drill Core

General Information

Primary Commodities: gold, lead, silver
Secondary Commodities: cobalt, copper, zinc
Deposit Type(s): Vein Polymetallic Ag-Pb-Zn+/-Au
Location(s): 63°35'9" N - -132°1'55" W
NTS Mapsheet(s): 105N09
Location Comments: 1 Kilometres
Hand Samples Available: No
Last Reviewed:

Capsule

Work History

Staked as Greg cl (Y32767) in Jul/69 by Atlas Exploration Ltd for the Hess Project (Atlas, Quebec Cartier Mining Company, Phillip Brothers (Canada) Ltd) which carried out prospecting and geochemical sampling later in the year.

Restaked as Plata cl 1-280 (Y68588) and Inca cl 1-32 (Y68955) in August and Sep/72 following detailed prospecting by a joint venture between Dynasty Exploration Ltd (80%) and Atlas Exploration Ltd (20%), which carried out grid soil sampling, geological mapping, geophysical test surveying, hand trenching and drilled 6 holes (400.8 m) in 1972; construction of a winter road, a bush airstrip 10 km to the south, and 25 km of tote road on the claims plus grid soil sampling, detailed mapping and bulldozer trenching in 1973; staked Plata cl 281-288 (Y85186) in Sep/73; and further trenching in 1974. Atlas changed its name to Cima Resources Ltd in 1974 and Dynasty changed to Cyprus Anvil Mining Corporation in 1975.

A. Harman and Z. Lavoie, under an agreement with Cyprus Anvil, mined and shipped about 81.6 tonnes of hand cobbed ore to the Trail smelter in 1976. The Spis cl (YA42179) was tied on to the northeast in Aug/80 by the Argent Project (Rio Alto Exploration Ltd, Radex Resources Ltd, ABM Mining Group Inc, Ebony Resources Ltd and Welcome North Mines Ltd), which carried out geochemical soil sampling later in the year.

Control of the Plata property was acquired by Dome Petroleum Ltd in 1981. In 1983, the property was sold to Dawson Eldorado Gold Exploration Ltd and Silvercrest Resources Corporation, which mined 450 tonnes from open cuts and shipped it to a smelter. Most of the 1 360 tonnes mined and smelted in 1984 was mined from the Plata 2 Vein, while the remainder came from the nearby Inca vein system.

Between Nov/84 and Feb/85, Dawson Eldorado drove a 260 m crosscut about 100 m vertically below the 2 Vein open pit in a joint venture with AVF Group (Primary Exploration Ltd and Royal Bank Venture Capital Ltd) and drilled 13 holes in 1985. Dawson Eldorado changed its name to Dawson Eldorado Mines Ltd in 1985 and optioned the property to Pacific Trans-Ocean Resources Ltd, which drilled holes (670 m) on the #4 Vein and mined 74 tonnes from the Plata #6 Vein and 40 tonnes from the Plata #4 Vein in 1987. Dawson Eldorado transferred the Plata claims to Gold City Resources Inc in Aug/91. Gold City transferred the Plata claims to Avanti Minerals Ltd in Aug/93 and in Dec/94 Avanti Minerals Ltd transferred the Plata claims to Avanti Minerals (1994) Inc.

A private company, Big Blackfoot Mine Inc, subsequently acquired control of the claims and optioned a 70% interest in the property to Yukon Gold Corporation in Jul/96 and drilled 6 holes (750 m) later in the year. Big Blackfoot Resources Ltd acquired Big Blackfoot Mines in Oct/96. Yukon Gold changed its name to Alliance Pacific Gold Corporation in Jun/97, which drilled 16 percussion holes (200 m) over the following winter. The company later changed its name to International Alliance Resources, before dropping the option in Dec/2000.

Big Blackfoot then optioned the property to Copper Ridge Explorations Inc in May/2001 and after Copper Ridge dropped the option, to First Star Innovations Inc. in Apr/2003.

Strategic Metals acquired the property in 2007. Strategic Metals flew and airborne magnetic and VTEM survey over the entire property in 2007. Rockhaven Resources Ltd. bought the Plata and Inca properties from Strategic Metals in exchange for stock in Rockhaven's company in 2008. Rockhaven's 2008 exploration program included diamond drilling (4113 m in 51 holes), excavator trenching and a VTEM geophysical survey primarily targeting the Plata thrust fault. Drilling expanded the area of known mineralization within the Plata thrust fault 500 m down-dip and 850 m along strike. A new surface showing of gold and silver rich material was also discovered through trenching.

Rockhaven's 2009 program consisted of excavator trenching and diamond driling (346.6 m). The drilling tested an area between the P-3 and P-4 veins, located 300 m apart, which confirmed the continuity of mineralization between the two veins.

In March 2011, Silver Predator Corporation optioned the property from Rockhaven and drilled 2565.56 m in 17 holes. Seven holes were directed toward the P-6 Zone, five holes targeted the Aho Zone, four holes were directed toward the P-2 Zone, and one hole was collared at the P-12 Zone. Drilling at the P-6 Zone returned encouraging results, including 1655 g/t silver over 1.0 m, 846.5 g/t silver over 1.3 m and 699.0 g/t silver and 0.72 g/t Au over 1.53 m. Drill holes targeting the P-2 Zone yielded intercepts of up to 1060 g/t silver and 3.86% zinc over 0.87 m and 110 g/t silver and 39.77% zinc over 0.93 m. Silver Predator later dropped the option.

In October 2015, the Plata property was transferred back to Strategic Metals. In 2017, Strategic did some road upgrading at the site.

Capsule Geology

The more than 14 veins comprising the Plata occurrence occur over a 2 by 5 km area. Two types of veins are present, both hosted in fault or fracture zones cutting the structural fabric in Proterozoic and/or Lower Cambrian limestone, quartzite and shale and unconformably overlying Devonian shale and chert. The Plata 1,2,3,5 and 6 Veins, and many other minor occurrences, occupy NE or NW-striking fracture sets in the structural hanging wall of a major thrust fault. The mineralized veins consist of galena and sphalerite in a siderite gangue. Silver occurs in tetrahedrite-rich sections associated with galena. Silver to lead ratios are highly variable, ranging from 1:1 to 10:1 over short distances on a single vein.

Most of the exploration, development and production has been concentrated on a galena-rich section of the 2 Vein. This deposit occurs along the southwest-plunging contact between Late Proterozoic limestone and overlying Devonian shale. The exploration adit intersected the vein about 100 m below and some distance to the northeast of the mining bench. The adit and subsequent underground drilling intersected five weak vein zones mineralized with siderite and sphalerite.

The 4 Vein occupies a major gently southwest-dipping thrust fault that is associated with a 1 to 3 m wide quartz feldspar porphyry dyke of probable mid Cretaceous age. Mineralization consists of disseminated pyrite, arsenopyrite, tetrahedrite and other sulphosalts in a massive white quartz gangue. Lenses of massive pyrite-pyrrhotite-galena-sulphosalt are also present. Specimens of the latter material range up to 20.9 g/t Au and about 6800 g/t Ag.

The 1983 shipments, which were mined mainly from the 2 Vein and partly from material stockpiled in 1973 from 5 and 6 Veins, averaged 4 050 g/t Ag and 59.3% Pb. The 1984 shipments from the 2 Vein averaged 5656 g/t Ag and 70% Pb while the 1987 shipment graded about 6 900 g/t Ag. The 1976 shipment was mined from Veins 1, 22, 6 and reportedly averaged about 7 700 g/t Ag and 80% Pb. Metallurgical testing showed the flotation of the galena-rich mineralization in the 2 Vein would produce a 92% recovery but that the complex Ag-Au ore in the 4 Vein was not amenable to flotation.

Drilling in 1996 on the 4 Vein and its downdip extension, intersected quartz-sulphide mineralization in hole Plata-2 that assayed 17.14 g/t Au and 4.5 g/t Ag over 2.1 m. Reserves for the 4 Vein in Nov/96 were reported as 453 592 tonnes grading 3.77 g/t Au, 376.71 g/t Ag and 10% combinded Pb-Zn.

In 2009, one of two drill holes completed between the P3 and P4 veins returned an assay of 360.00 g/t Ag, 3.29 g/t Au, 1.98% Pb and 4.17% Zn over 1.64 m.

Various historical resource estimates are quoted in reports, probably from internal company reports, none of which are NI 43-101 compliant.

Work History

Date Work Type Comment
7/1/2020 Pre-existing Data
7/1/2017 Development, Surface
7/1/2011 Drilling 17 holes, 2,565.00 m
7/1/2011 Geochemistry
7/1/2009 Geochemistry
7/1/2009 Geochemistry
7/1/2008 Airborne Geophysics
7/1/2007 Airborne Geophysics
7/1/2007 Studies
7/1/2007 Remote Sensing
7/1/2001 Geology
7/1/1974 Development, Surface
7/1/1974 Development, Surface
7/1/1972 Geochemistry
7/1/1968 Geochemistry
7/1/1968 Geology
7/1/1967 Geochemistry
12/31/2009 Drilling Two holes, 346.6 m.
12/31/2009 Trenching
12/31/2008 Drilling Fifty-one holes, 4,113 m.
12/31/2008 Ground Geophysics VTEM survey.
12/31/2008 Trenching
12/31/2007 Airborne Geophysics Also VTEM survey.
12/31/1998 Drilling Sixteen holes, 200 m.
12/31/1996 Drilling Six holes, 750 m.
12/31/1987 Drilling Fifteen holes, 670 m.
12/31/1987 Development, Underground Shipped 114 t of ore.
12/31/1985 Drilling Thirteen underground drill holes, 260 m.
12/31/1984 Development, Underground Shipped 1,360 tonnes to smelter.
12/31/1983 Trenching Shipped 450 t to smelter.
12/31/1976 Trenching
12/31/1974 Trenching
12/31/1973 Development, Surface
12/31/1973 Geology
12/31/1973 Geochemistry
12/31/1973 Trenching
12/31/1973 Development, Surface Twenty-five km Tote road.
12/31/1972 Drilling Six holes, 401 m.
12/31/1972 Geochemistry
12/31/1972 Trenching
12/31/1972 Other
12/31/1969 Geochemistry Also rock and silt sampling.
12/31/1969 Other
12/13/1985 Development, Underground Continued mining.
12/13/1972 Ground Geophysics Horizontal Shootback method. Test survey.
12/1/1987 Lab Work/Physical Studies
10/1/2021 Geochemistry

Assessment Reports that overlap occurrence

Report Number Year Title Worktypes Holes Drilled Meters Drilled
096200 2011 Assessment Report on the 2011 Diamond Drilling at the Plata Project Diamond - Drilling 17 2565
095669 2009 Assessment Report Describing Diamond Drilling, Excavator Trenching, Geochemical Sampling and Prospecting at the Plata Project Diamond - Drilling, Rock - Geochemistry, Soil - Geochemistry, Prospecting - Other, Backhoe - Trenching 2 346.55
095668 2008 Assessment Report Describing Diamond Drilling, Excavator Trenching, Geophysical Surveys, Geochemical Sampling, Prospecting and Water Surveys at the Plata Project Magnetic - Airborne Geophysics, VTEM - Airborne Geophysics, Diamond - Drilling, Silt - Geochemistry, Soil - Geochemistry, Backhoe - Trenching 51 4113
095607 2007 Assessment Report Describing Geophysical Surveys, Geochemical Sampling, Prospecting and Water Surveying at the Plata Project Magnetic - Airborne Geophysics, VTEM - Airborne Geophysics, Environmental Assessment/Impact - Studies, Photogrammatic - Studies
091705 1976 Bulk Sampling and Preliminary Economic Evaluation of the Plata and Inca Mineral Claim Groups Located in Bostock Range, Hess Mountains Northeast, Yukon Territory Bulk Sample - Lab Work/Physical Studies, Preliminary Economic Assessment - Studies
061153 1974 Application For Mineral Assistance Grant Plata Mineral Claims Group Air Strip - Development, Surface, Winter Road - Development, Surface, Rock - Geochemistry, Detailed Bedrock Mapping - Geology, Mechanical - Trenching
061152 1973 Application for Northern Mineral Assistance Grant Proposed Exploration Plata Mineral Claims Orthophoto - Airphotography, Diamond - Drilling, Soil - Geochemistry, Line Cutting - Other, Handblast - Trenching 6 400.80
019829 1973 Northern Mineral Assistance Grant Geochemical, Geological, Cat Trenching and Engineering Evaluation Report on the Plata Group Soil - Geochemistry, Regional Surficial Mapping - Geology, Line Cutting - Other, Hydraulic - Trenching
019828 1972 Geological, Geochemical, Geophysical, Hand Trenching and Diamond Drilling Report on the Plata Group Rock - Geochemistry, Silt - Geochemistry, Soil - Geochemistry, Regional Bedrock Mapping - Geology, EM - Ground Geophysics, Line Cutting - Other, Hand - Trenching 6 400.80
061864 1972 Application For Northern Mineral Assistance Grant Plata Mineral Claim Group Rock - Geochemistry, Detailed Bedrock Mapping - Geology
019809 1968 Hess Area Project Proposed Property Follow-Up 1968 Field Season Research/Summarize - Pre-existing Data
019033 1968 Atlas Explorations Limited Project Report 1968 Hess River Area Silt - Geochemistry, Soil - Geochemistry, Regional Bedrock Mapping - Geology
018947 1967 Hess River Project Report Rock - Geochemistry, Soil - Geochemistry, Detailed Bedrock Mapping - Geology
019032 1967 Hess River Project Report Data Compilation - Pre-existing Data

Related References

Number Title Page(s) Reference Type Document Type
YEG1996 Yukon Exploration and Geology 1996 25 Indian & Northern Affairs Canada/Department of Indian & Northern Development: Exploration & Geological Services Division Annual Report
1986GeolVol1_12 Geology of the Plata-Inca gold-silver veins, Yukon Indian & Northern Affairs Canada/Department of Indian & Northern Development: Exploration & Geological Services Division Annual Report Paper
ARMC016486 Geological overlay map - 105N/9 Property File Collection Geoscience Map (Geological - Bedrock)
ARMC016487 Geochemical overlay map - 105N/9 Property File Collection Geochemical Map
ARMC018079 Geochemical results and claim group map of sheet 105N/9 Property File Collection Geochemical Map
ARMC018080 Geochemical results map of 105N/9 Property File Collection Geochemical Map
ARMC018087 Geochemical field sheet map showing key map of Plata group as well as additional notations Property File Collection Geochemical Map
ARMC018088 Geochemical field map - 105N/9 Property File Collection Geochemical Map
ARMC018091 Geological field map of 105N/9 Property File Collection Geoscience Map (Geological - Bedrock)
ARMC018092 Geological field map of 105N/9 Property File Collection Geoscience Map (Geological - Bedrock)
ARMC018094 Geological field map of 105N/9 Property File Collection Geoscience Map (Geological - Bedrock)
ARMC018097 Geochemical field map - Mt. Aho area Property File Collection Geochemical Map
ARMC017711 Assay results and geochem results - 1972 - Plata project Property File Collection Assays
ARMC018128 Geology field sheet - 105N/9 Property File Collection Geoscience Map (Geological - Bedrock)
ARMC018131 Air photo overlays and stream sediment data sheets - A12321-77, 78, 74. 76, 71, 45, 72, A12251-404, 403, 406, 431, 432, 321, 322, 429, 405, A12260-48, 47 Property File Collection Geoscience Map (General)
BROCK000076 Scatter diagram and assay plan - Ag:Pb ratios - Plata project Property File Collection Geoscience Map (General)
01-073 Plata Project, Report on 2001 Field Program, Mayo Mining District Yukon Government: Energy, Mines and Resources YMEP Report

Resource/Reserve

Year Zone Type Commodity Grade Tonnage Amount Reported Amount 43-101 Compliant Cut-off
1996 PLATA - 4 VEIN (OPEN PIT) Historical Estimate gold 3.77 g/t 453,592 No No Unknown
Reported figure indicates proven and probable reserves but figures are not National Instrument 43-101 compliant. Reported for historical purposes.; From Canadian Mines Handbook 2002-03, p. 63 listed under Big Blackfoot Resources Ltd. Also reported 10% combined lead zinc but not calculations explaining breakdown of minerals reported. Uncertain where original figures came from.
1996 PLATA - 4 VEIN (OPEN PIT) Historical Estimate silver 377 g/t 453,592 No No Unknown
Reported figure indicates proven and probable reserves but figures are not National Instrument 43-101 compliant. Reported for historical purposes.; From Canadian Mines Handbook 2002-03, p. 63 listed under Big Blackfoot Resources Ltd. Also reported 10% combined lead zinc but not calculations explaining breakdown of minerals reported. Uncertain where original figures came from.
1996 Plata-P4? (Open pit) Historical Estimate silver 294.85 g/t 206,000 No No unknown
Lueck and Pudar, 1996, reported in Carlson and Fields, 2001.
1996 Plata- P4? (Open Pit) Historical Estimate gold 3.63 g/t 206,000 No No Unknown
Lueck and Pudar, 1996, reported in Carlson and Fields, 2001.
1987 Plata Thrust (Undetermined) Historical Estimate silver 340 g/t 450,000 No No unknown
YEG 1996, p.25. Probably taken from Van Angeren, 1986?
1987 Plata Thrust (Undetermined) Historical Estimate gold 8 g/t 450,000 No No unknown
YEG 1996, p.25. Probably taken from Van Angeren, 1986?

Production

Date Commodity Amount Comment
1/1/1976 Ag 9020 kilograms intermittent high-grade mining since 1976 to 1984, 290,000oz Ag in 2041 tonnes of hand-sorted material

Drill core at YGS core library

Number Property Year Drilled Core Size Photos Data
PL-08-16 Plata 2008 HQ 0 2
PL-08-17 Plata 2008 HQ 0 2
PL-08-19 Plata 2008 HQ 0 2
PL-08-20 Plata 2008 NQ2 0 2
PL-08-25 Plata 2008 NQ2 0 2
PL-08-33 Plata 2008 NQ2 0 2
PL-08-37 Plata 2008 NQ2 0 2
PL-08-47 Plata 2008 HQ 0 1