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Occurrence Details


Occurrence Number
105N 003
Occurrence Name
Plata
Occurrence Type
Hard-rock
Status
Deposit


General Information

Primary Commodities: lead, gold, silver
Secondary Commodities: zinc, cobalt, copper
Deposit Type(s): Vein Polymetallic Ag-Pb-Zn+/-Au
Location(s): 63.585830 N, -132.031940 W
NTS Mapsheet(s): 105N09
Location Comments: 1 Kilometres
Hand Samples Available at YGS: No

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.

Location Map

Last Updated: Jul 4, 2022

Work History

Year Work Type Comment
2020 Pre-existing Data: Data Compilation
2017 Development, Surface: Access Road
2011 Drilling: Diamond 17 holes, 2,565.00 m
2011 Geochemistry: Drill Core
2009 Drilling: Diamond Two holes, 346.6 m.
2009 Trenching: Mechanical
2009 Geochemistry: Rock
2009 Geochemistry: Soil
2008 Drilling: Diamond Fifty-one holes, 4,113 m.
2008 Ground Geophysics: EM VTEM survey.
2008 Trenching: Mechanical
2008 Airborne Geophysics: VTEM
2007 Airborne Geophysics: Magnetic Also VTEM survey.
2007 Airborne Geophysics: VTEM
2007 Remote Sensing: Photogrammetry
2007 Studies: Environmental Assessment/Impact
2001 Geology: Bedrock Mapping
1998 Drilling: Percussion Sixteen holes, 200 m.
1996 Drilling: Diamond Six holes, 750 m.
1987 Development, Underground: Drifting/Raising Shipped 114 t of ore.
1987 Drilling: Diamond Fifteen holes, 670 m.
1987 Lab Work/Physical Studies: Bulk Sample
1985 Drilling: Diamond Thirteen underground drill holes, 260 m.
1985 Development, Underground: Drifting/Raising Continued mining.
1984 Development, Underground: Drifting/Raising Shipped 1,360 tonnes to smelter.
1983 Trenching: Mechanical Shipped 450 t to smelter.
1976 Trenching: Hand
1974 Trenching: Mechanical
1974 Development, Surface: Air Strip
1974 Development, Surface: Winter Road
1973 Development, Surface: Access Road Twenty-five km Tote road.
1973 Development, Surface: Air Strip
1973 Geochemistry: Soil
1973 Geology: Bedrock Mapping
1973 Trenching: Mechanical
1972 Drilling: Diamond Six holes, 401 m.
1972 Geochemistry: Soil
1972 Other: Prospecting
1972 Trenching: Hand
1972 Ground Geophysics: EM Horizontal Shootback method. Test survey.
1972 Geochemistry: Rock
1969 Geochemistry: Soil Also rock and silt sampling.
1969 Other: Prospecting
1968 Geochemistry: Silt
1968 Geology: Regional Bedrock Mapping
1967 Geochemistry: Silt

Regional Geology - Terrane

Group: Ancestral North America
Affinity: W Laurentia
Name: North America - basinal strata
Realm: Laurentia


Regional Geology - Bedrock

Supergroup:
Group/Suite: Earn
Formation: Portrait Lk/Prevost/L Devonian beds?
Member:
Terrane: Laurentia
Period Max: Devonian
Age Max: 410 MA
Period Min: Devonian
Age Min: 359 MA
Rock Major: chert/shale/argillite
Rock Minor: barite/limestone
Reference: Roots et al. (1995) - YGS OF 1995-7(G)
Geological Unit (1M): DME
Geological Unit (250K): DME2

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
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
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
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
061864 1972 Application For Northern Mineral Assistance Grant Plata Mineral Claim Group Rock Geochemistry, Detailed Bedrock Mapping Geology
019033 1968 Atlas Explorations Limited Project Report 1968 Hess River Area Silt Geochemistry, Soil Geochemistry, Regional Bedrock Mapping Geology
019809 1968 Hess Area Project Proposed Property Follow-Up 1968 Field Season Research/Summarize Pre-existing Data
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) Document Type
YEG1996 Yukon Exploration and Geology 1996 25 Annual Report
091705 Bulk Sampling and Preliminary Economic Evaluation of the Plata and Inca Mineral Claim Groups Located in Bostock Range, Hess Mountains Northeast, Yukon Territory Assessment Report
1986GeolVol1_12 Geology of the Plata-Inca gold-silver veins, Yukon Annual Report Paper
ARMC016486 Geological overlay map - 105N/9 Geoscience Map (Geological - Bedrock)
ARMC016487 Geochemical overlay map - 105N/9 Geochemical Map
ARMC018079 Geochemical results and claim group map of sheet 105N/9 Geochemical Map
ARMC018080 Geochemical results map of 105N/9 Geochemical Map
ARMC018087 Geochemical field sheet map showing key map of Plata group as well as additional notations Geochemical Map
ARMC018088 Geochemical field map - 105N/9 Geochemical Map
ARMC018091 Geological field map of 105N/9 Geoscience Map (Geological - Bedrock)
ARMC018092 Geological field map of 105N/9 Geoscience Map (Geological - Bedrock)
ARMC018094 Geological field map of 105N/9 Geoscience Map (Geological - Bedrock)
ARMC018097 Geochemical field map - Mt. Aho area Geochemical Map
ARMC017711 Assay results and geochem results - 1972 - Plata project Assays
ARMC018128 Geology field sheet - 105N/9 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 Geoscience Map (General)
BROCK000076 Scatter diagram and assay plan - Ag:Pb ratios - Plata project Geoscience Map (General)
01-073 Plata Project, Report on 2001 Field Program, Mayo Mining District YMEP Report
095607 Assessment Report Describing Geophysical Surveys, Geochemical Sampling, Prospecting and Water Surveying at the Plata Project Assessment Report
019032 Hess River Project Report Assessment Report
018947 Hess River Project Report Assessment Report
019829 Northern Mineral Assistance Grant Geochemical, Geological, Cat Trenching and Engineering Evaluation Report on the Plata Group Assessment Report
019809 Hess Area Project Proposed Property Follow-Up 1968 Field Season Assessment Report
019033 Atlas Explorations Limited Project Report 1968 Hess River Area Assessment Report
061152 Application for Northern Mineral Assistance Grant Proposed Exploration Plata Mineral Claims Assessment Report
095668 Assessment Report Describing Diamond Drilling, Excavator Trenching, Geophysical Surveys, Geochemical Sampling, Prospecting and Water Surveys at the Plata Project Assessment Report
095669 Assessment Report Describing Diamond Drilling, Excavator Trenching, Geochemical Sampling and Prospecting at the Plata Project Assessment Report
097213 Assessment Report Describing Road Construction at the Plata Property Assessment Report
061864 Application For Northern Mineral Assistance Grant Plata Mineral Claim Group Assessment Report
061153 Application For Mineral Assistance Grant Plata Mineral Claims Group Assessment Report
096200 Assessment Report on the 2011 Diamond Drilling at the Plata Project Assessment Report
019828 Geological, Geochemical, Geophysical, Hand Trenching and Diamond Drilling Report on the Plata Group Assessment Report
Citations
Canadian Mines Handbook 2002-03, p. 63 listed under Big Blackfoot Resources Ltd.
Carlson, G. and Fields, M., 2001. Plata Project, Report on 2001 Field Program, YEIP 01-073.
Eaton, D.W., Assessment report describing geophysical surveys, geochemical sampling, prospecting and water surveys at the Plata project , Assessment report 095607, http://yma.gov.yk.ca/095607/
Lueck, B A , and Pudar, Z , 1996 Geological Assessment Report for the Plata-lnca Property, Internal company report, 21 p
Van Angeren, P , 1986 Plata-lnca Property Summary, Internal company report
Last Updated: Oct 1, 2018

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
1996 PLATA - 4 VEIN (OPEN PIT) Historical Estimate silver 377 g/t 453,592 No No Unknown
1996 Plata-P4? (Open pit) Historical Estimate silver 294.85 g/t 206,000 No No unknown
1996 Plata- P4? (Open Pit) Historical Estimate gold 3.63 g/t 206,000 No No Unknown
1987 Plata Thrust (Undetermined) Historical Estimate silver 340 g/t 450,000 No No unknown
1987 Plata Thrust (Undetermined) Historical Estimate gold 8 g/t 450,000 No No unknown
Last Updated: Oct 1, 2018

Production

Date Commodity Amount Comment
1976-01-01 Ag 9,020 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

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