Canadian Journal of Earth Sciences Long-lived deformation history recorded along the Precambrian Thelon and Judge Sissons faults, northeast Thelon Basin, Nunavut Journal: Canadian Journal of Earth Sciences Manuscript ID cjes-2020-0108.R2 Manuscript Type: Article Date Submitted by the 08-Nov-2020 Author: Complete List of Authors: Hunter, Rebecca; Laurentian University, Harquail School of Earth Sciences; British Columbia Geological Survey Branch Lafrance, Bruno; Laurentian University, Harquail School of Earth Sciences Draft Heaman, Larry; University of Alberta, Earth and Atmosphere Sciences Thomas, David; Cameco Corp Aberdeen Lake, strike-slip fault, U-Pb zircon geochronology, Rae domain, Keyword: Thelon fault, Judge Sissons fault Is the invited manuscript for consideration in a Special Not applicable (regular submission) Issue? : © The Author(s) or their Institution(s) Page 1 of 82 Canadian Journal of Earth Sciences 1 Long-lived deformation history recorded along the Precambrian Thelon and Judge Sissons 2 faults, northeast Thelon Basin, Nunavut 3 4 R.C. Hunter, B. Lafrance, L.M. Heaman, and D. Thomas 5 6 R.C. Hunter (corresponding author): Mineral Exploration Research Centre, Harquail School of 7 Earth Sciences, Goodman School of Mines, Laurentian University, Sudbury, ON, Canada P3E 8 2C6; e-mail: [email protected]; phone: 306-371-0020 9 10 Present address: British Columbia Geological Survey, 1810 Blanshard Street, Victoria, BC Canada 11 V8T 4J1; e-mail: [email protected]; phone: 250-419-8744 12 13 B. Lafrance: Mineral Exploration Research Centre, Harquail School of Earth Sciences, Goodman 14 School of Mines, Laurentian University, Sudbury, ON, Canada P3E 2C6; e-mail: 15 [email protected]; phone: 705-675-1151 16 17 L.M. Heaman: Department of Earth and Atmospheric Sciences, University of Alberta, AB, 18 Canada T6G 2E3; e-mail: [email protected]; phone: 780-492-2778 19 20 D. Thomas: 760 Trent Crescent, Saskatoon, SK, Canada S7H 4S5; e-mail: 21 [email protected]; phone: 306-291-6093 22 23 24 1 © The Author(s) or their Institution(s) Canadian Journal of Earth Sciences Page 2 of 82 25 Abstract 26 27 The ENE-striking Thelon and Judge Sissons faults of south-central Nunavut are well-preserved, and 28 record long-lived dextral transcurrent movement with complex reactivation and fluid flow 29 histories. The faults cut across Archean gneisses, Paleoproterozoic plutons, and a Mesoproterozoic 30 sedimentary basin in the Rae domain of the western Churchill Province. They formed and were 31 reactivated during multiple deformation events beginning with an initial faulting event at 1830- 32 1760 Ma, followed by an epithermal faulting event at 1760-1750 Ma and late reactivation events 33 at 1600-1300 Ma. The initial faulting event produced the core-damage zone architecture of the 34 faults. Damage zones are characterized by multiple fracture sets, quartz veins and hydrothermal 35 crackle breccias, surrounding core zonesDraft defined by multiple mosaic to chaotic breccias and 36 cataclasites with dextral slip indicators. The epithermal faulting event is expressed by the presence 37 of crosscutting comb, crustiform-cockade and lattice-bladed quartz hematite carbonate veins, 38 and is likely associated with a magmatic event of similar age. The late reactivation events resulted 39 in the formation of irregular, non-cohesive crackle to mosaic breccias and gouges, which became 40 the primary pathways for uranium-bearing hydrothermal fluids and the formation of unconformity- 41 type uranium deposits. The Thelon and Judge Sissons faults are similar to other major continental 42 faults in the Rae domain (e.g. McDonald fault, Wager Bay shear zone), which formed during the 43 Paleoproterozoic Taltson-Thelon and Trans-Hudson orogenies, and to modern analogues, such as 44 the Karakorum, Altyn Tagh, and Hunan-Jaingxi faults, which formed during the Himalayan- 45 Tibetan orogeny and experienced prolonged hydrothermal and even hot spring activity. 46 47 Key words: Aberdeen Lake, strike-slip fault, U-Pb zircon geochronology, Rae domain, Thelon fault, 48 Judge Sissons fault. 2 © The Author(s) or their Institution(s) Page 3 of 82 Canadian Journal of Earth Sciences 49 1. Introduction 50 51 Studies on the architecture, kinematics, and alteration history of long-lived, strike-slip faults and 52 their related fracture networks provide important insights into the structural and hydrothermal 53 evolution of fault zones. Strike-slip faults are important crustal-scale continental structures that 54 accommodate horizontal movement as transform faults along tectonic plate boundaries and as 55 major transcurrent faults during collisional tectonics (Woodcock 1986; Sylvester 1988). 56 Continent-continent collision between the Indian and Eurasian plates led to the creation of the 57 Himalayan-Tibetan orogenic belt, which is bordered within its hinterland regions by a vast network 58 of transcurrent, right- and left-lateral, strike-slip faults (Molnar and Tapponnier 1975; Tapponnier 59 and Molnar 1977; Armijo et al. 1989). In such collisional tectonic settings, older pre-existing 60 structures including transcurrent faults (WoodcockDraft 1986) may be reactivated and undergo changes 61 in their slip kinematics over time, adding structural complexities to these long-lived structures. As 62 noted by Faulkner et al. (2003), the study of brittle fault rock products developed in the upper crust 63 is commonly impeded by their poor preservation as non-cohesive gouge, fractured rocks and 64 breccias, which are typically lost to erosion and weathering. As a result, the best studied faults are 65 relatively young structures (Eocene to Miocene) and located in arid climates where weathering is 66 minimal, for example, the individual faults of the large San Andreas fault system (Chester et al. 67 1993; Schultz and Evans 2000; Faulkner et al. 2003; Wibberley and Shimamoto 2003; Cembrano 68 et al. 2005; Jeffries et al. 2006; Faulkner et al. 2008; Bradbury et al. 2011). The challenges are even 69 greater for Precambrian strike-slip faults, including well-exposed examples such as the McDonald 70 and Bathurst faults, and Wager Bay shear zone of the northwest Canadian Shield, which are not 71 only affected by erosion and weathering but are also modified by multiple post-faulting tectonic, 72 magmatic, metamorphic, and hydrothermal events. Although, studies of these faults have provided 3 © The Author(s) or their Institution(s) Canadian Journal of Earth Sciences Page 4 of 82 73 detailed timing and tectonic constraints with respect to their ductile evolution (Thomas et al. 1976; 74 Henderson and Broome 1990; Therriault et al. 2017; Ma et al. 2020), the late brittle deformation 75 events remain much more difficult to resolve. 76 77 Brittle fault zones comprise three main components: (1) a core zone that accommodates 78 displacement along discrete slip surfaces; (2) a fractured damage zone that surrounds the core zone 79 and forms in response to repeated slip events; and (3) the undeformed protolith, which may be 80 preserved as lozenges between higher strain domains (Sibson 1977; Chester and Logan 1986; 81 Caine et al. 1996; Faulkner et al. 2003, 2010). Paleoseismic studies suggest that earthquake events 82 occur more frequently along strike-slip faults than along normal or reverse dip-slip faults (Sylvester 83 1988). Thus, large-scale strike-slip faultsDraft typically form during multiple slip and aftershock events 84 over periods of tens of millions of years. Crustal ruptures enhance fluid flow (Cox et al. 1986; 85 Sibson 1987; Micklethwaite and Cox 2006) and may result in the formation of ore deposits along 86 the faults (Henley 1985). 87 88 In this paper we describe the formation of internal structures along two well-exposed, 89 Paleoproterozoic faults named the Thelon and Judge Sissons faults that formed in the hinterland 90 regions of the Taltson-Thelon and Trans-Hudson orogenies. High crustal levels of these faults are 91 well-exposed at surface and their 3D geometry is constrained by multiple drill holes. The 92 investigation into the age and tectonic history of the Thelon and Judge Sissons faults provides 93 additional insights into how fractures, veins, and breccias formed and changed through time, 94 eventually creating the conditions that drove and focused hydrothermal fluid flow during 95 reactivation events. 4 © The Author(s) or their Institution(s) Page 5 of 82 Canadian Journal of Earth Sciences 96 97 2. Regional Geology 98 99 The western Churchill Province is divided into three Archean lithotectonic domains, namely, the 100 Rae and Hearne domains and the Chesterfield block, separated by a Paleoproterozoic suture zone 101 named the Snowbird tectonic zone (Fig. 1, Hoffman 1988; Ross et al. 2000; Mahan and Williams 102 2005; Berman et al. 2007; Martel et al. 2008). The Rae and Hearne domains consist of ca. 2750- 103 2650 Ma Neoarchean greenstone belts that were intruded by ca. 2667 Ma granitic plutons (Hinchey 104 et al. 2011) and invaded by a large number of ca. 2610-2580 Ma granitic and gabbroic plutons of 105 the Snow Island Suite. Snow Island Suite magmatism is further manifested as subvolcanic sills and 106 volcanic flows of the Pukiq Lake FormationDraft (Roddick et al. 1992; Peterson et al. 2015a). 107 108 The Archean Hearne and Rae cratons were reworked and metamorphosed to amphibolite-granulite 109 grade during four major Paleoproterozoic orogenies, including the Arrowsmith (ca. 2550-2300 110 Ma), Taltson-Thelon (ca. 2000-1930 Ma), Snowbird (ca. 1900 Ma), and Trans-Hudson (ca. 111 1870-1800 Ma) orogenies (Ashton 1988; Hrabi et al. 2003; Zaleski 2005; Berman et al. 2007). 112 During rifting of the cratons following the Arrowsmith orogeny, fluvial, marine, and lacustrine 113 sediments of the ca. 2300-1910 Ma Amer and Ketyet River groups were deposited in rift basins 114 unconformably overlying the greenstone belts (Heywood 1977; Tippett and Heywood 1978; 115 Patterson 1986; Rainbird et al. 2010; Calhoun et al. 2011, 2012; Pehrsson et al. 2013; Jefferson et 116 al.