Lithological and structural setting of structurally controlled gold mineralization in the Wilding Lake region, central Newfoundland

Abstract

The structurally controlled central Newfoundland gold belt is emerging as one of the next significant mining jurisdictions in Canada. Gold mineralization is associated with crustal-scale faults that preserve synorogenic conglomerates, similar to the setting of orogenic gold in the Archean Abitibi greenstone belt. Recent exploration in the Wilding Lake region exposed a system of auriferous quartz veins hosted within sedimentary and volcanic rocks. Detailed lithological and structural documentation of these newly exposed zones was conducted to examine controls on gold mineralization and place the vein system into a regional context. Field data demonstrate that the main 'Elm' quartz vein extends for approximately 230 m along strike, is up to 2 m wide and cuts the conglomerate host within an oblique sinistral shear zone that accommodated north-northeast-directed thrusting. An early set of moderately dipping extensional quartz veins, consistent with oblique sinistral shear, emanate from the main vein. A later, more steeply dipping set of extensional quartz veins crosscut the main vein and the earlier vein set, and are consistent with a component of horizontal extension. Chalcopyrite and malachite occur locally in the early vein set, but are more abundant overall within the younger vein set. A nearly conjugate set of steeply dipping extension fractures crosscut the main vein and the two vein sets. These fractures are filled typically with vuggy quartz and unaltered and altered sulphides. Field data are consistent with progressive deformation characterized by early oblique compressional sinistral shear and subsequent components of subhorizontal extension and minor dextral strike-slip.

Reply to the discussion by van Staal et al. on “The northern Appalachian terrane wreck model”

“…van Staal and Barr 2012). The western Exploits subzone may contain an additional subdivision due to the Cape Ray -Victoria Lake shear system (CRVLSS) (e.g., Brown 1973;Dubé et al 1996;Honsberger et al 2019aHonsberger et al , 2019b) inferred here to continue into the northern Newfoundland offshore.…”

“…The TW model removes a need to infer Salinic, Acadian, or Neoacadian oceans and interprets Western Ganderia, Eastern Ganderia, Avalonia, and Meguma terranes as one accreted terrane subsequently deformed (Keppie and Keppie 2014;Landing et al 2022). Documented faults crossing Newfoundlandmainly here the Cape Ray -Victoria Lake shear system (CRVLSS; Valverde-Vaquero and van Staal 2001van Staal , 2002Honsberger et al 2019aHonsberger et al , 2019b, and faults crossing southeastern New Brunswickmainly here the Norumbega fault system (e.g., Ludman 1998;West 1999), are linked to the inferred duplication and reversal. Causal movements probably started in the Devonian, and continued into the Late Paleozoic (cf.…”

Latest Silurian syntectonic sedimentation and magmatism and Early Devonian orogenic gold mineralization, central Newfoundland Appalachians, Canada: Setting, structure, lithogeochemistry, and high-precision U-Pb geochronology

“…The Rogerson Lake Conglomerate structural corridor hosts a highly prospective orogenic gold system, which includes an approximately four to five million ounce gold deposit in Neoproterozoic rocks at Valentine Lake (Lincoln et al, 2018) and numerous gold showings and prospects hosted within the conglomerate (e.g., Wilding Lake prospect; Figs. 1 and 2; Evans, 1996;Honsberger et al, 2019aHonsberger et al, , 2019bHonsberger et al, , 2020b. The gold-mineralized Neoproterozoic rocks at Valentine Lake include trondhjemite, tonalite, gabbro, and mafic dikes of the Valentine Lake Intrusive Suite (Fig.…”

“…Northeast and along-strike of Valentine Lake, orogenic gold mineralization is hosted in the Rogerson Lake Conglomerate and associated felsic volcanic and volcaniclastic rocks that comprise the Wilding Lake pros-pect (Honsberger et al, 2019a(Honsberger et al, , 2019b. In this area of central Newfoundland (Fig.…”

“…One such fault corridor that extends for more than 200 km southwest to northeast across central Newfoundland is remarkably similar to Archean orogenic gold-bearing fault systems with respect to geology, structure, and distinct geologic processes (Figs. 1 and 2; Tuach et al, 1988;Tuach, 1992;Evans, 1996;Dubé and Lauzière, 1997;Wardle, 2005;Lincoln et al, 2018;Honsberger et al, 2019aHonsberger et al, , 2020a. This fault corridor includes the Cape Ray Fault Zone in southwestern Newfoundland (Dubé et al, 1996;van Staal et al, 1996) and the Wood Brook fault and Victoria Lake Shear Zone in central Newfoundland (Figs.…”