Churchill Craton

The Churchill Craton is the northwest section of the

magmatic events. The Western Churchill province is the part of the Churchill Craton that is exposed north and west of the Hudson Bay. The Archean (ca. 1.83 Ga) Western Churchill province contributes to the complicated and protracted tectonic history of the craton and marks a major change in the behaviour of the Churchill Craton with many remnants of Archean supracrustal and granitoid

rocks.

Major tectonometamorphic intervals

2.69 Ga: deformation in the northern Hearne Domain.

2.685 Ga: greenschist-grade metamorphism and deformation in the central Hearne Domain.
2.60 Ga: granitoid
plutonism
across the northern Hearne and Rae Domains.
2.50-2.55 Ga: metamorphism and deformation in the northern Hearne domain.
1.9 Ga: metamorphism and deformation in the northern Hearne Domain.
1.83 Ga: magmatism and deformation in the northern Hearne and Rae Domains.
1.755 Ga: plutonism in the western Hearne and eastern Rae Domains.

^[1]

Hearne Domain, Western Churchill province

A north-northwest-trending crustal segment transects from Kaminak Lake (central Hearne Domain) in the south to Yathkyed Lake (northern Hearne Domain) in the northwest, consisting of Archean supracrustal belts that preserve mostly Archean mafic to felsic volcanic rocks (greenschist-grade supracrustal and granitoids), metamorphic cooling of hornblende and Proterozoic biotite.

This section of the Churchill province was formerly called the Ennadai-Rankin

hydrothermal event accompanying a deformation along this contact area.^[2]

Murmac Bay Group, Western Churchill province

The Murmac Bay Group exposed in the southwestern half of the Western Churchill Craton, near

sedimentary rocks These rocks sit on ca. 3 Ga granitoids and have been affected by several deformational and metamorphic

events.

Taltson Magmatic Zone and Taltson basement

The

magmatic rocks

between 1.99 and 1.92 Ga.

Economic geology

There is aggressive diamond exploration drilling in the south Slave Province, NWT, Churchill Craton (at the northwest corner of the

Keewatin regions of Nunavut and the north-central region of Alberta are regions that are all underlain by diamond-friendly cratonic rocks of the Slave Craton, Churchill Craton and the Buffalo Head Craton. The diamonds being found in the NWT were created 50 to 600 mya during cataclysmic explosions of kimberlite

, a molten magma originating up to 400 kilometers beneath the Earth's surface.

Unlike the Slave Craton, which is covered with shallow lakes and swamp, the eastern part of the Churchill Craton is drier. Kimberlites may be obscured by foliage rather than water, therefore many targets may be drillable during the summer, not just during the short winter window when lakes are frozen and daylight is available. In comparison, drilling in the Eastern Arctic is too remote compared to the Slave Craton, which is serviced by the fully developed infrastructure of Yellowknife. The Eastern Arctic is serviced by the smaller town of Rankin Inlet, which in turn is serviced by barge during summer.

References

Notes

^ Sandeman 2001, pp. 3–4
^ Sandeman 2001, pp. 4–5

Sources

Sandeman, H. A. (2001). "⁴⁰Ar-³⁹Ar Geochronological Investigations of the Central Hearne Domain, Western Churchill Province, Nunavut: A Progress Report" (PDF). Geological Survey of Canada, Current Research. 2001-F4. Retrieved 28 May 2016.

[1] Sandeman 2001, pp. 3–4

[2] Sandeman 2001, pp. 4–5

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