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Occurrence Details


Occurrence Number
105F 134
Occurrence Name
Ukon Showing 4
Occurrence Type
Hard-rock
Status
Showing


General Information

Primary Commodities: rare earths
Secondary Commodities: zirconium, niobium
Aliases: Guano
Deposit Type(s): Unknown
Location(s): 61.491780 N, -132.4206 W
NTS Mapsheet(s): 105F08
Location Comments: Georeferenced from Map 14 in AR 095343 (p. 625).
Hand Samples Available at YGS: No

Capsule

Work History

Staked as Guano, etc. cl (YA00242) in Jul-Sep/76 by Ukon Joint Venture (Chevron and Kerr Addision), which explored with mapping, geochem and radiometric surveys in 1976 and rock sampling in 1979. Restaked as PS cl (YB00978) in Aug/87 by Mountain Province Mining Inc, which took one rock sample from the claim block in an undisclosed location. In 2010, chip sampling was carried out near the occurrence and a helicopter radiometric survey was flown over the entire property.

Regional Geology
 
The occurrence is located on the Cassiar Platform, a curvilinear shelf that formed in the early Paleozoic, roughly parallel to the western margin of the North American craton but separated from it by the Selwyn Basin. Shallow marine miogeoclinal sediments were emplaced on the platform until Late Devonian time. Block faulting and local uplift during the Late Devonian and Mississippian resulted in deposition of carbonaceous shale and chert pebble conglomerate in the Selwyn Basin and across the platform. Local explosive volcanism produced volcaniclastic material and flows of the Pelly Mountains volcanic belt. The belt comprises localized submarine volcanic centres generated in an extensional environment that are separated by basins in-filled with sediments and volcaniclastic rocks. Several cogenetic syenite and trachyte domes and small stocks are the remains of vent areas. Subsequent deformation is a result of Mesozoic thrust faulting related to the Cordilleran orogeny, emplacement of Cretaceous intrusions and Tertiary strike-slip movement along the major northwest-trending Tintina Fault, 30 km to the northeast.
 
 
Property Geology
 
In 1976, a chip sample 230 m northeast of the occurrence assayed 300 ppm beryllium, but the occurrence was first identified as a showing (#4 in AR 090269) in 1977. Property mapping places the showing within the Devonian syenitic True Blue pluton.  Work in 1977 located a swarm of small dykes crosscutting volcanic rocks at the syenite pluton contact. The dykes are fine-grained, dark to light green with pinkish tinges, and are up to 1 m thick. Although the dykes are strongly radioactive, uranium assays are low.
 
A grab sample taken at the occurrence in 2010 as part of a rare earth exploration program returned 0.73% TREO, 0.38% ZrO2, 0.01% U3O8 and 0.25% Nb2O5.

Location Map

Last Updated: Mar 12, 2020

Work History

Year Work Type Comment
2010 Airborne Geophysics: Gamma-Ray Spectrometry
2010 Geochemistry: Rock
1987 Geochemistry: Rock
1979 Geochemistry: Rock
1976 Airborne Geophysics: Gamma-Ray Spectrometry
1976 Geochemistry: Rock
1976 Geology: Detailed Bedrock Mapping

Regional Geology - Terrane

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Regional Geology - Bedrock

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Related References

Number Title Page(s) Document Type
YEG1979_80-pg55 Rare earth elements in the Guano-Guayes skarn property Pelly Mountains, Yukon Territory Annual Report Paper
MIR1976 Mineral Industry Report 1976 Annual Report
1979Chronic Geology of the Guano-Guayes rare earth element bearing skarn property, Pelly Mountains, Yukon Territory MSc Thesis
Citations

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