Queen Maud block: A newly recognized Paleoproterozoic (2.4–2.5 Ga) terrane in northwest Laurentia
- Michael E.J. Schultz1,
- Thomas Chacko1,
- Larry M. Heaman1,
- Hamish A. Sandeman2,
- Antonio Simonetti3 and
- Robert A. Creaser3
- 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
- 2Northwest Territories Geoscience Office, Yellowknife, Northwest Territories X1A 2R3, Canada
- 3Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
Abstract
The Queen Maud block of Arctic Canada is central to understanding the Proterozoic tectonic history of northwestern Laurentia, but its crustal history is largely unknown. Results of an in situ U-Pb zircon, monazite, and whole-rock Sm-Nd study through the central and eastern Queen Maud block indicate: (1) widespread 2.46–2.50 Ga magmatism derived from Neoarchean source rocks, (2) an extensive NE-trending 2.44–2.39 Ga sedimentary belt characterized by 2.45–2.50 Ga detritus, and (3) regional ca. 2.39 Ga granulite metamorphism. There is no evidence of metamorphic or magmatic activity at 1.9–2.0 Ga, concurrent with orogenesis in the adjacent Taltson-Thelon belt. We propose that the eastern Queen Maud block was the site of an incipient continental rift ca. 2.5 Ga. Exhumation of 2.46–2.50 Ga granitoids produced in the early stages of rifting provided detritus to a short-lived basin that underwent granulite metamorphism ca. 2.39 Ga.
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- Accepted 23 March 2007.
- Received 18 December 2006.
- Revision received 21 March 2007.
- Geological Society of America
