Occurrence Details


Occurrence Number:
105F 141
Occurrence Name:
Garnet Greisen
Occurrence Type:
Hard-rock
Status:
Showing
Date printed:
4/29/2025 12:40:13 PM

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General Information
Capsule
Work History
References

General Information

Primary Commodities: rare earths
Secondary Commodities: niobium, zirconium
Aliases: Guano
Deposit Type(s): Skarn
Location(s): 61°30'10.32" N - -132°26'29.14" W
NTS Mapsheet(s): 105F08
Location Comments: Based on showing location in AR 095343
Hand Samples Available: No
Last Reviewed:

Capsule

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
 
The occurrence was first identified as Garnet Skarn in Archer, 1977 (AR 090269). The showing consists of very coarse crystals within the syenitic True Blue Pluton. The mineralization has been identified as greisen, an endoskarn. XRD mineral identification confirmed that the main minerals are subhedral, pale, clear, orange grossularite in a medium to fine grained matrix of mica, augite and kaolin. The adjacent syenite has also been altered, with a conspicuous red-altered phase primarily formed of plagioclase. The occurrence of grossularite and plagioclase indicates that the fluids were calcium-rich. A grab sample of the calcium-feldspar altered rock returned 1.24% TREO, 0.07% ZrO2 and 0.07% Nb2O5 (AR 095343).
 
Fluorite has been identified within the host syenite in the area.

Work History

Date Work Type Comment
12/13/2010 Geochemistry Contour soil sampling line downhill from the occurrence
12/13/2010 Airborne Geophysics Great Western Minerals options the claims from True North Gems
12/13/2010 Airborne Geophysics
12/13/2009 Geochemistry McEvoy Geosciences performed exploration work on behalf of True North Gems
12/13/2002 Other Restaked as Shark 1-94 claims in 2002 and 2003 by Archer Cathro on behalf of True North Gems
12/13/1987 Other Restaked as White 1-123 cl in Aug/87 by Mountain Province Mining Inc.
12/13/1977 Airborne Geophysics Contour line airborne radiometrics
12/13/1977 Geochemistry
12/13/1977 Ground Geophysics
12/13/1976 Geochemistry
12/13/1976 Geology
12/13/1976 Other Staked as Guano claims by Ukon Joint Venture (Chevron and Kerr Addison)

Related References

Number Title Page(s) Reference Type Document Type
YEG1979_80-pg55 Rare earth elements in the Guano-Guayes skarn property Pelly Mountains, Yukon Territory Indian & Northern Affairs Canada/Department of Indian & Northern Development: Exploration & Geological Services Division Annual Report Paper
MIR1976 Mineral Industry Report 1976 Indian & Northern Affairs Canada/Department of Indian & Northern Development: Geology Annual Report
1979Chronic Geology of the Guano-Guayes rare earth element bearing skarn property, Pelly Mountains, Yukon Territory University of British Columbia MSc Thesis