Tehery-Wager Geoscience Project - Canada

Tehery-Wager Geoscience Project:
Findings from the 2015 bedrock mapping campaign
Holly Steenkamp, Canada-Nunavut Geoscience Office
Natasha Wodicka, Geological Survey of Canada
Christopher Lawley, Geological Survey of Canada
Tony Peterson, Geological Survey of Canada
Carl Guilmette, Université Laval
The Tehery-Wager Project
Regional geoscience initiative:
• Targeted bedrock mapping
• Surficial geology mapping
• Targeted stream sediment surveys
Collaborative project:
• Geological Survey of Canada
(GEM 2 - South Rae Activity)
• Canada-Nunavut Geoscience Office
(SINED)
Contributions from:
• Université Laval
• Dalhousie University
• University of Victoria
• University of New Brunswick
• Université du Québec à Montréal
• Nunavut Arctic College
Duration:
• 2 field seasons (2015/2016), outputs through 2̴ 019
Project Location
Davis Strait
Hudson Bay
Mapping prior to 2015…
• Reconnaissance mapping
• Wright, 1955
• Lord and Wright, 1967
• Heywood, 1967
• Gordon and Heywood,
1988 Daly Bay complex
• Henderson et al., 1990
Wager Shear Zone
• Panagapko et al., 2003 –
RPM
• New reconnaissance
survey by the GSC in 2012
• McMartin et al., 2013
• Wodicka et al., in prep
Project Objectives
1) Characterize and define distinct units within the Archean gneiss
• Define their relationships with overlying supracrustal rocks
• Snow Island suite K-feldspar porphyritic monzogranite?
2) Document stratigraphy of supracrustal belts, determine
depositional ages and environments
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Correlations to other known sequences?
3) Determine the timing, extent and degree of metamorphism and
deformation in the area related to the Snowbird Tectonic Zone
and/or terminal collision of the Trans-Hudson Orogeny
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Peak pressure/temperature of metamorphism, spatial distribution
Development of trans-lithospheric fault systems
4) Evaluate the economic potential of the area
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Metal and carving stone potential? Diamond potential?
Do large-scale faults provide favourable environments for mineralization?
2015 Field Season
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June 30 – Aug 2
14 field crew
5 camp crew
1 Bell 206 LR
Turbo Otter supply
runs
2015 Mapping
Archean Tonalite to Granodiorite
• Biotite ± hornblende
• Granitic injections that cut foliation
and are subsequently deformed
• Pods, lenses, rafts of mafic rocks
(e.g. pyroxenite, diorite) and
supracrustal rocks (e.g. amphibolite,
calcsilicate)
• Van Breemen et al., 2007: U-Pb
zircon crystallization ages 2699 ± 11
Ma, 2701 ± 14 Ma
• Compositional complexity and
variability – likely more phases to
identify
Archean Monzo- to Syenogranite
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Contains biotite, magnetite, rare muscovite
Foliation defined by biotite, compositional layering
Cut by syenite dykelets that are subsequently transposed
Nature of contact with Archean tonalite-granodiorite is poorly exposed
Unknown age
K-Feldspar Porphyritic Monzogranite
K-Feldspar Monzogranite
Tonalite
• Rapakivi texture, coeval gabbro/diorite phases
• Similar characteristics to felsic plutonic rocks of the
2.6 Ga Snow Island suite
• Mylonitic zone at contact to underlying orthogneiss
Supracrustal Rocks
• Occur as panels between layers of Archean orthogneiss
• Granulite-facies mineral assemblages with partial retrogression
to amphibolite-facies phases
• Include:
• Sill-Bt quartzite (3.7-2.55 Ga detritus – Ferderber et al., 2013)
• Grt-Bt±Sill±melt semipelite with local psammite and pelite layers
• Grt-Cpx amphibolite
Supracrustal Rocks
• Includes:
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Garnetite
Iron formation
Ultramafic boudins
Calcsilicate
Rare marble
Ultrapotassic Intrusions
• Zoned, bimodal intrusions with magma mixing textures
• Well exposed plutonic bodies, only 1 minette dyke identified
• Correlative with Christopher Island formation and Martel syenite?
Cpx-Bt Syenite
Cpx Monzonite
Phlg Clinopyroxenite
Undeformed Granitic Rocks
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Monzogranite to syenogranite dykes and sills
Homogeneous texture and mineralogy
Rare fluorite
Contain xenoliths of orthogneiss and paragneiss
Possibly correlative with felsic rocks of the 1.85-1.81 Ga Hudson
suite
Economic Considerations
• Stream sediment and till sample findings of McMartin et al. (2013)
highlight locations for follow-up work:
• Gossanous metasedimentary rocks – anomalous Ag, Au, Bi, Cu and
presence of safflorite
• Ultrapotassic intrusions – REE potential in most fractionated parts
of the plutons
• Diamond potential
• Nanuq property (Peregrine Diamonds)
• Carving stone
Thank you!
• Hamlet of Chesterfield Inlet
• Hudson Bay Helicopters
• Ookpik Aviation
• Polar Continental Shelf Program
• Discovery Mining
Also See:
Wodicka et al., 2015 – GSC Open File 7970, 2015 field report
McMartin et al., 2015 – Poster Session at Arena – 2015 Surficial mapping
Coming Soon – Steenkamp et al., 2015 – CNGO Summary of Activities report