Geology of Elu Inlet and Melville Sound, Nunavut, Arctic Canada

The north–northwest-striking Bathurst fault in the northeastern Slave craton displaced the 1.9 Ga Kilohigok basin and the ca. 2.02–1.96 Ga Thelon tectonic zone, and projects beneath the 1.7 Ga Thelon basin where unconformity-associated uranium deposits are spatially associated with basement faults. Here we investigate the deformation–temperature–time history of the Bathurst fault rocks using structural and microstructural observations paired with U–(Th–)Pb and 40Ar/39Ar geochronology. Highly strained hornblende-bearing granitoid rocks, the predominant rock type on the northeastern side of the Bathurst fault in the study area, show ambiguous sense of shear suggesting flattening by coaxial deformation. Quartz and feldspar microstructures suggest ductile deformation occurred at ≥500 °C. Along the main fault trace, brittle features and hydrothermal alteration overprint the pervasive ductile flattening fabric. In situ U–Th–Pb dating of synkinematic monazite suggests ductile fabric formation at ca. 1933 ± 4 Ma and ca. 1895 ± 11 Ma, and zircon from a cross-cutting dyke constrains the brittle deformation to ≤1839 ± 14 Ma. 40Ar/39Ar dating of fabric-defining minerals yield cooling ages of ca. 1920–1900 Ma and ca. 1900–1850 Ma for hornblende and muscovite, respectively, and a maximum cooling age of ca. 1840 Ma for biotite. We suggest the ca. 1933–1895 Ma ductile flattening fabric developed during orthogonal collision and indentation of the Slave craton into the Thelon tectonic zone and Rae craton. Brittle deformation on the Bathurst fault was localised parallel to the ductile flattening fabric after ca. 1840 Ma and preceded Thelon basin deposition. Brittle deformation features in Bathurst fault rocks preserve evidence for fluid–rock interaction and enhanced basement permeability, suggesting the fault is a possible conduit structure for mineralising fluids.

show abstract

Localisation of the brittle Bathurst fault on pre-existing fabrics: a case for structural inheritance in the northeastern Slave craton, western Nunavut, Canada

Svieda

Kellett

Godin

et al. 2020

Can. J. Earth Sci.

View full text Add to dashboard Cite

show abstract

Extent and significance of the Racklan–Forward Orogen in Canada: far-field interior reactivation during Nuna assembly

Pehrsson

Eglington

Rainbird

et al. 2023

View full text Add to dashboard Cite

Mesoproterozoic orogenesis is well established on the western and southern flanks of Laurentia in the well-known Racklan-Forward and Mazatzal Orogens, but its significance within the previously assembled interior of the supercontinent Nuna has not been established. We examine regional isotopic and structural evidence for Mesoproterozoic deformation in the ca . 1.7-1.63 Ga Hornby Bay, Elu, Thelon and Athabasca intracontinental basins, and present evidence for Mesoproterozoic reactivation of Paleoproterozoic structures in Wopmay and Trans-Hudson orogens. Racklan-Forward Orogeny in the interior of north Laurentia comprises north-south trending, high angle, east-vergent folds and thrusts that occur across a region 1660 kilometers wide and over 1000 kilometers long, stretching from the Yukon to near Hudson Bay and from Banks Island to below the Western Canada Sedimentary Basin. The structures progress from ductile amphibolite and greenschist facies in the Racklan type area to subgreenschist facies and ultimately brittle or brittle-ductile in the far foreland, showing a predominant thick-skinned style typical of many intracontinental orogens. We present compiled low-temperature thermochronologic data, including ages of spatially associated uraninite mineralization, to characterize the scope of reactivation of basement structures in the Archean Rae craton in Nuna's interior. We compare the nature of widespread far-field reactivation in Racklan-Forward Orogen with other orogens of Nuna's assembly to show it is unusual for Nuna's peripheral margin. We suggest that ca. 1.6 Ga continent-continent collision of North Australia with northwest Laurentia propagated stresses far into the interior as a result of combined favourable pre-existing structural grain and a weak subcontinental lithosphere mantle in Rae craton due to repeated episodes of refertilization across 500 Ma of accretion and intrusion. Cratons that experience the complex, two-sided collision and protracted upper plate setting during supercontinent assembly noted herein may be particularly susceptible to extensive foreland propagation of peripheral orogens.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Geology of Elu Inlet and Melville Sound, Nunavut, Arctic Canada

Cited by 2 publications

References 27 publications

Localisation of the brittle Bathurst fault on pre-existing fabrics: a case for structural inheritance in the northeastern Slave craton, western Nunavut, Canada

Localisation of the brittle Bathurst fault on pre-existing fabrics: a case for structural inheritance in the northeastern Slave craton, western Nunavut, Canada

Extent and significance of the Racklan–Forward Orogen in Canada: far-field interior reactivation during Nuna assembly

Contact Info

Product

Resources

About