Metallogenic Evolution of the Mackenzie and Eastern

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Geoscience Canada

Metallogenic Evolution of the Mackenzie and Eastern Selwyn Mountains of Canada’s Northern Cordillera, Northwest Territories: A Compilation and Review Luke Ootes, Sarah A. Gleeson, Elizabeth Turner, Kirsten Rasmussen, Steve Gordey, Hendrick Falck, Edith Martel and Kelly Pierce

Volume 40, Number 1, 2013 Article abstract The Mackenzie and eastern Selwyn Mountains, Northwest Territories, Canada, URI: https://id.erudit.org/iderudit/geocan40_1art02 are the northeast expression of the Cordilleran orogen and have a geologic history that spans the last one billion years. The region has undergone a See table of contents diverse tectonic evolution, which is reflected in an equally diverse collection of mineral deposits and prospects. More than 300 of these deposits and prospects have been documented in this area of the Northwest Territories and here they Publisher(s) are categorized into mineral deposit types and their mode of formation evaluated and highlighted. Stratiform/stratabound Cu–Ag occurrences are The Geological Association of Canada hosted in the Neoproterozoic Coates Lake Group, generally preserved in the hanging wall of the Cretaceous Plateau fault, and define a belt through the ISSN central part of the Mackenzie Mountains. Low-grade phosphatic stratiform iron (47.5% Fe) occurs as iron formation in the Neoproterozoic Rapitan Group 0315-0941 (print) in the very northwest of the Mackenzie Mountains. Sedimentary exhalative 1911-4850 (digital) Zn–Pb (± Ba) deposits are preserved in Cambrian through Devonian strata of the Selwyn Basin in the eastern Selwyn Mountains. Numerous Explore this journal carbonate-hosted Zn–Pb (± base-metals) occurrences are located in the Paleozoic strata of the Mackenzie Platform in the Mackenzie Mountains. Cretaceous felsic-intermediate plutons, which occur throughout the eastern Cite this article Selwyn Mountains, are associated with tungsten skarn (proximal to intrusions), base-metal skarn (distal from intrusions), rare metals, semi-precious Ootes, L., Gleeson, S. A., Turner, E., Rasmussen, K., Gordey, S., Falck, H., Martel, tourmaline related to pegmatites, and vein-hosted emeralds. Other resources of E. & Pierce, K. (2013). Metallogenic Evolution of the Mackenzie and Eastern potential interest include coal deposits, placer gold, and possible Carlin-type Selwyn Mountains of Canada’s Northern Cordillera, Northwest Territories:: A gold deposits that have recently been identified farther west in the Yukon. Compilation and Review. Geoscience Canada, 40(1), 40–69.

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5Geological Survey of Canada sions), base-metal skarn (distal from 625 Robson Street intrusions), rare metals, semi-precious Vancouver, BC, Canada, V6B 5J3 tourmaline related to pegmatites, and vein-hosted emeralds. Other resources SUMMARY of potential interest include coal The Mackenzie and eastern Selwyn deposits, placer gold, and possible Car- Mountains, Northwest Territories, lin-type gold deposits that have recent- Canada, are the northeast expression ly been identified farther west in the of the Cordilleran orogen and have a Yukon. geologic history that spans the last one billion years. The region has undergone SOMMAIRE Metallogenic Evolution of a diverse tectonic evolution, which is Les monts Mackenzie et ceux de la reflected in an equally diverse collec- chaîne orientale de Selwyn, dans les the Mackenzie and Eastern tion of mineral deposits and prospects. Territoires du Nord-Ouest, au Canada, Selwyn Mountains of More than 300 of these deposits and sont l'expression au nord-est de prospects have been documented in l'orogène de la Cordillère, et leur his- Canada’s Northern this area of the Northwest Territories toire géologique s’étale sur le dernier milliard d’années. La région a été and here they are categorized into min- Cordillera, Northwest l’hôte d’une évolution tectonique diver- eral deposit types and their mode of sifiée, et cela se reflète par une suite Territories: A Compilation formation evaluated and highlighted. tout aussi diversifiée de gisements and Review Stratiform/stratabound Cu–Ag occur- minéraux et d’indices prometteurs. rences are hosted in the Neoprotero- 1 2 Plus de 300 de ces dépôts et indices Luke Ootes , Sarah A. Gleeson , zoic Coates Lake Group, generally pre- 3 prometteurs ont été documentées dans Elizabeth Turner , Kirsten Ras- served in the hanging wall of the Cre- 4 5 cette région des Territoires du Nord- mussen , Steve Gordey , Hendrik taceous Plateau fault, and define a belt 1 1 Ouest, et le présent article ils sont Falck , Edith Martel , and Kelly through the central part of the Pierce1 classés en types de gîtes minéraux, et Mackenzie Mountains. Low-grade l’attention est portée sur leur mode de 1Northwest Territories Geoscience Office phosphatic stratiform iron (47.5% Fe) formation. Les gisements de Cu-Ag Box 1500, Yellowknife, NT, Canada, occurs as iron formation in the Neo- stratiformes ou stratoïdes sont encais- X1A 2R3 proterozoic Rapitan Group in the very sés dans le Groupe néoprotérozoïque E-mail: [email protected] northwest of the Mackenzie Moun- de Coates Lake, et ils sont générale- tains. Sedimentary exhalative Zn–Pb (± 2 ment préservés dans l'éponte Department of Earth and Atmospheric Sci- Ba) deposits are preserved in Cambrian supérieure de la faille du plateau cré- ences, University of Alberta, 1-26 Earth through Devonian strata of the Selwyn tacé, et ils forment une bande qui tra- Sciences Building, Edmonton, AB, Canada, Basin in the eastern Selwyn Mountains. verse la partie centrale des monts T6G 2E3 Numerous carbonate-hosted Zn–Pb (± Mackenzie. Le fer se retrouve dans des 3Department of Earth Sciences base-metals) occurrences are located in gisements phosphatées stratiformes à Laurentian University, 935 Ramsey Lake the Paleozoic strata of the Mackenzie faible teneur (47,5% Fe) qui provient Road, Sudbury, ON, Canada, P3E 2C6 Platform in the Mackenzie Mountains. de formations de fer dans le Groupe Cretaceous felsic-intermediate plutons, néoprotérozoïque de Rapitan situé 4Department of Earth and Ocean Sciences which occur throughout the eastern dans la pointe nord-ouest des monts University of British Columbia, 6339 Stores Selwyn Mountains, are associated with Mackenzie. Des gisements sédimen- Road, Vancouver, BC, Canada, V6T 1Z4 tungsten skarn (proximal to intru- taires exhalatifs de Zn-Pb (± Ba) sont

8 60°N 60 40°W 0°W préservés dans des strates cambriennes °W 160°W à dévoniennes du bassin de Selwyn 140°W 20°W 1 100°W dans la portion est des monts Selwyn. De nombreux indices de Zn-Pb (± 0°N métaux communs) dans des roches car- 6 bonatées des strates paléozoïques de la plate-forme de Mackenzie, des monts Mackenzie. Des plutons felsiques intermédiaires crétacés, qui pointent Mackenzie tout au long de la chaîne est de Selwyn, Mountains sont associées à des skarns de tungstène (proximaux), à des skarns de 40°N métaux communs (distaux), à des concentrations de métaux rares, de tour- RM maline semi-précieuses liés aux peg- Canada matites, et à des émeraudes filoniennes.

Parmi d’autres ressources d'intérêt, on USA 40°N retrouve des gisements de charbon, d'or alluvionnaire, et d’éventuels gisements d'or de type Carlin qui ont été découverts récemment plus à l'ouest au Yukon.

INTRODUCTION Mineral deposits record evidence of 20°N lithospheric-scale processes and thus Mexico provide important constraints on the °N tectonic evolution of a region. The 20 Mackenzie and eastern Selwyn Moun- tains (MSM) of Canada’s Northwest Territories are the easternmost sub- province (Foreland belt) of the Cordilleran orogen. The MSM region 120°W 100°W 80°W is the northern extent of the Canadian Rocky Mountains and the Sevier fold- Figure 1. Geographic relief map of North America with the location of the thrust belt, the now deformed ancient Mackenzie Mountains in the Cordillera of northern Canada. Transparent grey is margin of western North America ancient North American margin, now preserved as the Rocky Mountains (RM) in (Fig. 1; Gabrielse and Yorath 1991; Canada and Sevier fold and thrust belt in the US. Thick black line with teeth on the Gabrielse et al. 1991; Cecile et al. 1997; hanging wall side indicates the frontal thrust of the Cordilleran orogen. The map is DeCelles 2004). The geologic evolution modified after DeCelles (2004). of the southern parts of the Foreland belt has been well-studied and the rela- 2009; Turner and Long 2008; Martel et for a review of the metallogenic evolu- tionship between rock units and ore al. 2011; Rasmussen et al. 2011). tion of this vast area and a summary deposits is well-documented (e.g., Whereas many recent publications have of our current understanding of min- Gabrielse and Yorath 1991; Dawson et focused on the metallogenic evolution eral deposits in the context of sedi- al. 1991; Gabrielse et al. 1991; Burch- of North American geological mentary, intrusive, and tectonic events. fiel et al. 1992; Hutchinson and Albers provinces, commodity-specific mineral The deposits and prospects are 1992; Cecile et al. 1997; DeCelles 2004; deposit types, or mineral deposits as a grouped into deposit types based on Ross et al. 2005; Colpron et al. 2007; function of particular geological events host-rock lithology, age, structural Lund 2008; Wells and Hoisch 2008). (e.g., Hart et al. 2004a, b; Dickinson style, and ore mineralogy and are The broad-scale geologic evolution of 2006; Goodfellow 2007; Goodfellow defined using overviews on similar the MSM has also been well-docu- and Lydon 2007; Hart 2007; Nelson deposit types in the literature (e.g., mented and some of the mineral and Colpron 2007; Lund 2008), the Hitzman et al. 2005; Goodfellow and deposits or deposit groups have been metallogenic evolution of the MSM Lydon 2007). This synthesis will help studied (e.g., Aitken et al. 1982; area has not been synthesised compre- guide future mineral deposit research, Delaney et al. 1982; Jefferson and hensively in such a context. allow comparison with southern equiv- Ruelle 1986; Yeo 1986; Gordey et al. There are more than 300 pub- alents (southern Canada, United States, 1991; Narbonne and Aitken 1995; licly reported mineral deposits and and Mexico), and assist in searching Cecile et al. 1997; Goodfellow 2007; prospects in the MSM region. In this for, and classifying, new discoveries. Wright et al. 2007; Pyle and Jones paper, these are collated as the basis 42

REGIONAL GEOLOGY tains Supergroup (Long and Turner Formation, deep water shale and tur- An overview of the geologic evolution 2012; Turner and Long 2012) and the bidites of the Sheepbed Formation, of the Mackenzie and eastern Selwyn younger Windermere Supergroup (Fig. platformal carbonate strata of the Mountains is provided and summa- 3A; Narbonne and Aitken 1995). The 4 Gametrail Formation, thick shallow- rized in Figures 2 and 3 (also see to 6 km-thick Mackenzie Mountains water, terrigenous, clastic strata of the Wright et al. 2007; Pyle and Jones Supergroup consists of, from oldest to Blueflower Formation, and the poorly 2009; Martel et al. 2011 and references youngest, sedimentary rocks of the exposed, shallow-water, carbonate- therein). This study draws significantly “H1-unit” (now Tobacco Formation; dominated rocks of the Risky Forma- upon numerous individual and group Turner and Long 2012), the Tsezotene tion (Fig. 3A; Narbonne and Aitken research conclusions; key references Formation, and the Katherine and Lit- 1995; MacNaughton et al. 2008). are provided and should be consulted tle Dal Groups (Fig. 3A; Long et al. for more detail. 2008; Martel et al. 2011). Uranium-lead Paleozoic The geological evolution of detrital zircon populations with ca. The Neoproterozoic–Cambrian bound- the MSM region spans about one bil- 1083 Ma and 1010 Ma dates from the ary is preserved in the main ranges of lion years, with the oldest recognized Katherine Group provide a maximum the Mackenzie Mountains, but sub- unit being a sequence of <1083 Ma age of deposition (Rainbird et al. 1996; Cambrian erosion has cut progressively sedimentary rocks (Fig. 3; Rainbird et Leslie 2009). A 778 Ma gabbro plug downward east to the mountain front, al. 1996). All of the metamorphic south of Coates Lake (Jefferson and where Cambrian strata directly overlie rocks in the study area belong to the Parrish 1989) and the cross-cutting ca. lower units of the Mackenzie Moun- greenschist or sub-greenschist facies 780 Ma Tsezotene sills (Harlan et al. tains Supergroup. The Cambrian except for contact metamorphic aure- 2003) provide a minimum age for the through Devonian (with minor Permi- oles around Cretaceous plutons, where Mackenzie Mountains Supergroup. The an) strata were deposited on the Neo- andalusite-bearing pelitic rocks indicate Tsezotene sills are associated with the proterozoic strata in an evolving pas- local amphibolite facies conditions “Little Dal basalts” and are part of the sive margin. In general, the sedimenta- (Gordey and Anderson 1993). Recog- Gunbarrel event (Dudás and Lustwerk ry rocks are preserved as platformal nized structures include syn-sedimenta- 1997; Harlan et al. 2003). Stratigraphy, facies in the northeast (Mackenzie Plat- ry extensional faults (Aitken and Cook sedimentology, and regional correla- form) and basinal facies to the south- 1974; Eisbacher 1981; Jefferson 1983; tions indicate that the overall deposi- west (Selwyn Basin; Figs. 2 and 3B; Pyle and Jones 2009; Turner and Long tional setting for the Mackenzie Moun- Morrow 1991; Gordey and Anderson 2008; Martel et al. 2011) and Creta- tains Supergroup was likely an epicra- 1993; Cecile et al. 1997). ceous-Tertiary folds and thrust faults tonic basin (Narbonne and Aitken Paleozoic platformal sedimen- (Morris and Nesbitt 1998; Mair et al. 1995; Long et al. 2008; Turner and tation was complex and influenced by 2006a; Pyle and Jones 2009; Martel et Long 2008). variations in crustal thicknesses inherit- al. 2011). Post-Berriasian to Campanian The Coates Lake Group is a ed from sub-Windermere and Cambri- strata (ca. 120 to 70 Ma) in the sequence of sabkha- and lagoon-relat- an extension (Cecile et al. 1997; Had- Mackenzie Mountains are tightly folded ed sedimentary rocks that were lari et al. 2012). This led to sedimenta- (Martel et al. 2011) indicating later deposited in a terrestrial rift environ- tion on a number of segmented plat- deformation. This is supported by radi- ment (Jefferson and Parrish 1989). The forms, arches, and basins, resulting in ogenic Ar cooling ages on micas from Coates Lake Group is positioned numerous formations with complex ca. 95 Ma plutonic rocks indicating unconformably above the Little Dal lateral thickness variations and facies that uplift and unroofing persisted until Group and Little Dal basalt and is relationships. For simplicity, this is at least 60 Ma (Barnes et al. 2007; Ras- unconformably overlain by the Rapitan referred to collectively as the Macken- mussen et al. 2007). Recent earth- Group of the Windermere Supergroup zie Platform (Fig. 2; Morrow 1991; quakes in the area indicate on-going (e.g., Eisbacher 1978; Jefferson and Gordey and Anderson 1993; Cecile et deformation (Hyndman et al. 2005). Ruelle 1986; Dudás and Lustwerk al. 1997; Martel et al. 2011). The oldest 1997). Cambrian strata in the Mackenzie Plat- Neoproterozoic The 5 to 7 km-thick, rift-relat- form consist of shallow-marine to flu- In the MSM area, Neoproterozoic suc- ed Windermere Supergroup uncon- vial quartz sandstone (Backbone cessions were deposited in extensional formably overlies the Coates Lake Ranges Formation). This is overlain by regimes (Narbonne and Aitken 1995; Group and the Mackenzie Mountains shallow-water Cambrian to Devonian Turner and Long 2008), possibly in the Supergroup (Fig. 3A; Eisbacher 1978; dolostone and limestone assigned to vicinity of what is now Australia, Narbonne and Aitken 1995). From the various formations (e.g., Sekwi, Rock- Siberia, South China, Antarctica, or base upward, the Windermere Super- slide, Broken Skull, Sunblood, Franklin West Africa (Hoffman 1991; Park et al. group in the MSM includes the <755 Mountain, Mount Kindle, Tsetso, Cam- 1995; Rainbird et al. 1996; Harlan et al. Ma glacial marine/rift-related Rapitan sel, Sombre, Arnica, and Bear Rock 2003; Sears and Price 2003; Li et al. Group (Yeo 1981; Ross and Villeneuve Formations; Fig. 3B), and capped by 2004; Li et al. 2007; Nelson and Col- 1997), the deep-water, shaly Twitya Middle Devonian open-marine fossilif- pron 2007; Evans 2009). The Neopro- Formation, shallower-water carbonate erous limestone (e.g., Landry, Grizzly terozoic strata can be divided into two and siliciclastic strata of the Keele For- Bear, Headless, Nahanni, and Hume groups; the older Mackenzie Moun- mation, the glacial-related Ice Brook Formations; see Morrow 1991; Gordey GEOSCIENCE CANADA Volume 40 2013 43

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Figure 2. Generalized geological map of the Mackenzie Mountains draped on a digital elevation model. Geology is simplified from Wheeler et al. (1996) with modifications following Martel et al. (2011) and D. Irwin and A. Okulitch (unpublished data). The approximate transition between the Lower Paleozoic Mackenzie Platform (MP) and Selwyn Basin (SB) is shown by a solid white line, modified after Gordey and Anderson (1993) and Martel et al. (2011). This transition shifted in position over time during the Paleozoic, so this is simply a generalized reference. Mineral occurrences are derived from the NORMIN.db (available at www.ntgomap.nwtgeoscience.ca). ARR – Arctic Red River; GR – Gayna River; KR – Keele River; LR – Liard River; MR – Mackenzie River; MtR – Mountain River; NNR – North Nahanni River; NWT – Northwest Territories; RR – Redstone River; RTR – Ravensthroat River; SNR – South Nahanni River; YT – Yukon Territory. 44 c. Simplified and c. 1999) and Pyle and Jones (2009). 1999) and Pyle Jones therein. Paleozoic Selwyn Basin therein. Paleozoic Stratigraphy of and eastern Selwyn Mountains with mineral occurrencesB) Phanerozoi the Mackenzie indicated. A) Neoproterozoic. modified after Narbonne and Aitken (1995), Dewing et al. (2006), Pyle and Jones (2009), and Martel et al. (2011) and references (1995), Dewing et al. (2006), Pyle and Jones modified after Narbonne and Aitken ( units after Dixon Cretaceous-Tertiary and Earn Groups. River and the Road Formation strata typically include the Rabbitkettle grey-shade(Note, record is preserved.) in sections A and B represents regions where no rock Figure 3. GEOSCIENCE CANADA Volume 40 2013 45 and Anderson 1993; Pyle and Jones Mesozoic tion scheme that is based on extensive, 2009; Martel et al. 2011). A significant Triassic and Cretaceous sedimentary recent, and internally consistent field feature of the Mackenzie Platform is units are only preserved locally (Figs. 2 observations. the Mackenzie Arch, a northwest- and 3B). The Cretaceous strata are Five mineral deposit types are trending locus of coalescing unconfor- foredeep deposits that reflect the colli- recognized and discussed in this paper. mities and formational thinning. East sional evolution of the continental Assignment of deposits to mineral of the arch, formation thicknesses margin to the west (Coney et al. 1980; deposit types was based on published increase, but only modestly, and then Mair et al. 2006a; Martel et al. 2011). reports on the deposits themselves or farther east units thin again to merge Mesozoic igneous rocks are dominated on related deposits elsewhere. Key ref- with unfolded Paleozoic platform by intermediate to felsic, ca. 110 to 90 erences to this literature are included in cover of the craton (Interior Platform; Ma Cretaceous plutons that intruded the text. Where necessary, overviews of e.g., Cecile et al. 1997). West of the Proterozoic and Paleozoic Selwyn each type are discussed in the context arch the platformal units increase sub- Basin strata within the Selwyn Moun- of their host geology. In some cases stantially in thickness to the facies tran- tains (Figs. 2 and 3B; Hart et al. 2004a, our classification scheme is straight sition into the Selwyn Basin (Morrow b; Rasmussen et al. 2007). The plutons forward (e.g., iron formation contains 1991). represent the southeastern extent of stratiform Fe). However, individual The relatively deeper water the Tombstone–Tungsten Suite (Hart occurrences of carbonate-hosted, Selwyn Basin strata were deposited et al. 2004a), and are interpreted to SEDEX, and intrusion-related deposits concomitantly with the sedimentary have formed in a distal, back-arc set- may be far more complex than this rocks on the Mackenzie Platform. The ting in response to collision of the simple classification indicates. Finally, oldest exposed units in the Selwyn Peninsular–Alexander–Wrangellia the intrusion-related deposits include a Basin are thick, turbiditic, clastic rocks Superterrane with the western margin diverse set of styles such as multiple of the Neoproterozoic through Cam- of North America (Mair et al. 2006a). skarn types and semi-precious gem- brian Hyland Group. Lower and Mid- stones. The mineral deposit types are dle Cambrian shales are sparsely pre- METHODS AND MATERIALS discussed chronologically in their served beneath the sub-Upper Cambri- The mineral prospects and deposits in tectono-stratigraphic context to illumi- an unconformity. The Upper Cambrian the MSM area are documented in the nate the metallogenic evolution of this is marked by basinal limestone of the Northern Minerals database vast region. Rabbitkettle Formation (Fig. 3B). (NORMIN), which is available through In Canada, since 2001, valid Ordovician to Devonian strata are the NWT Geoscience Office’s GoMap ore resource calculations must have dominated by siltstones, shales, and web portal (http://www.nwtgeo- employed the methodology set out by cherts of the older Road River Group science.ca). Mineral occurrence data in National Instrument 43-101 of the and younger Earn Group (Fig. 3B; Yukon are available through the Yukon Canadian Institute of Mining and Met- Gordey and Anderson 1993; Pyle and Geological Survey’s website allurgy (http://web.cim.org/stan- Jones 2009; Martel et al. 2011). (http://www.geology.gov.yk.ca), and dards/MenuPage.cfm?sec- During the Late Devonian to are not discussed further. The data in tions=177&menu=178) and developed Mississippian there was an abrupt NORMIN are derived from the sub- by the Canadian Securities Administra- change in deposition style, reflecting mission of assessment reports on min- tion. Therefore, resource estimates that complex tectonic events (e.g., Colpron eral claims (publicly available assess- predate this, or have not been pub- et al. 2007; Lemieux et al. 2011). The ment reports can be obtained through lished under these guidelines, are con- lack of evidence of compressional the NWT Geoscience Office website), sidered herein as ‘historical’ resource deformation, the presence of local syn- and from published maps or written estimates, indicating they do not meet sedimentary normal faults and of local publications. Other supplementary data NI-43-101 standards, and the reported felsic volcanic rocks are interpreted to are from Wright et al. (2007), Ootes et data may not accurately represent the reflect extension or transtension. As al. (2007), Mercier et al. (2008), Ootes mineral deposits in question. Devono–Mississippian tectonism and Martel (2010), and Martel et al. waned, clastic sedimentation was suc- (2011). METALLOGENIC EVOLUTION ceeded by lower Mississippian mixed NORMIN was used as a guide carbonate and siliclastic strata likely for classifying all of the documented Red-bed or Kupferschiefer-type Cu deposited on a muddy, shallow-marine mineral occurrences from the Macken- (± Ag) shelf (Tsichu Group, Cecile 2000; zie and eastern Selwyn Mountains. The oldest recognized mineral deposit Mattson Formation, Potter et al. 1993; Classification involved comparing host type in the MSM is stratabound copper Fig. 3B). Preservation of Carbonifer- rocks, structural style (e.g., stratiform hosted by the <780 Ma Coates Lake ous to Permian strata is fragmentary versus fault-hosted), commodities Group (Fig. 3A). This region is com- and limited to the westernmost and recorded (e.g., Zn–Pb versus Cu–Ag), monly referred to as the Redstone cop- southern parts of the Mackenzie and geographic location (e.g., Macken- per belt, and the mineralization is gen- Mountains (Fig. 3B; Gordey and zie Platform versus Selwyn Basin). erally preserved in the hanging wall of Anderson 1993; Martel et al. 2011). Many of the significant prospects and the Plateau fault (Fig. 4). The Coates deposits have been visited by the Lake Group is divided into three for- authors since 2003, yielding a classifica- mations; alluvial-fan and playa-lake 46

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Figure 4. Distribution of Neoproterozoic Coates Lake Group and associated copper occurrences preserved in the hanging wall of the Plateau fault. Green circles represent known locations of Kupferschiefer-type copper prospects. Embayments, denoted as yellow lines, are defined by the thickness and lithofacies of the Coates Lake Group. CLE – Coates Lake embayment; HLE – Hayhook Lake embayment; HCE – Hay Creek embayment; KRE – Keele River embayment; MRE – Mountain River embayment; TRE – Thundercloud Range embayment. Embayments are defined after Jefferson (1983) and Jefferson and Parrish (1989). Geographical abbreviations are in Figure 2. GEOSCIENCE CANADA Volume 40 2013 47

Table 1. Significant mineral deposits in the Mackenzie and eastern Selwyn Mountains. Time of Tectonic Environment of Deposit Name Deposit Type Commodity *Resource Host Unit Mineralization Formation

Transition zone Neoproterozoic Stratabound/stratiform 18.6 million tonnes between Redstone <780 Ma and >685 Ma Early rift sequence - shallow water in a Coates Lake Redbed-associated Cu- Cu +/- Ag @ 4.2% Cu and River and Coppercap (unconformably restricted basin-rifting margin Ag (Kupferschiefer-like) 9.62g/t Ag formations in Coates underlies Rapitan Lake Group Group)

Crest-IF / Rapitan Sayunei-Shezal Glacio-marine - subglacial rift Stratiform iron - hematite- 5.6 billion tonnes Neoproterozoic iron formation / Fe formations in Rapitan environment, possibly during glacial jasper iron formation @ 47.5% Fe <755 Ma and >685 Ma Snake River Group hiatus

^185.57 million Selwyn Howard's Stratiform SEDEX Deep water basin fill off shelf edge in rift Zn-Pb tonnes @ 5.20 Duo Lake Formation Early Silurian Pass region Zn-Pb (+/- Ba) environment Zn% & 1.79% Pb

3 styles - A) stratabound Zn; B) ^5.8 million tonnes structurally-hosted Zn-Pb; and C) vein- Carbonate-hosted @ >20% combined Rabbit Kettle Prairie Creek Zn-Pb-Ag Cambrian to Tertiary hosted Pb-Zn-Ag. B and C formed Zn-Pb Pb-Zn and 161 Formation during deformation but timing of g/tonne Ag mineralization remains unknown

50 million tonnes Structurally-hosted (breccia and vein- Carbonate-hosted Gayna River Zn-Pb-Ga @ 5% combined Little Dal Group Cambrian to Tertiary type) but timing of mineralization Zn-Pb Zn-Pb remains unknown

^2.9 million tonnes Intrusion-related (skarn) Lower Cambrian Proximal to felsic-intermediate intrusions Selwyn Cantung W-Cu @ 1.21% WO 95 Ma tungsten 3 limestone and marble in a distal back arc post-collision (PRODUCER)

Intrusion-related (skarn) ^33 million tonnes Lower Cambrian Proximal to felsic-intermediate intrusions Selwyn Mactung W-Cu 95 Ma tungsten @ 0.88% WO3 limestone and marble in a distal back arc post-collision

NOTE: * historical resource estimate unless otherwise indicated by ^NI-43-101 (2011 numbers) which only include indicated mineral resource (does not include inferred resources). deposits of the Thundercloud Forma- sitional normal faulting that formed a stratabound or stratiform lenses in the tion grade into the overlying sabkha series of half-grabens (Eisbacher 1981; “Transition Zone” between the Red- deposits of the Redstone River Forma- Jefferson and Ruelle 1986; Jefferson stone River and Coppercap Formations tion, which is overlain by marine car- and Parrish 1989). This extensional (Figs. 3A, 5A, and 6; Jefferson and bonate rocks of the Coppercap For- activity was probably related to incipi- Ruelle 1986). The relationship between mation (Figs. 3 to 6; Jefferson 1983; ent opening of the paleo-Pacific Ocean ore bodies and host rocks indicates Jefferson and Ruelle 1986). and the first stage of Rodinia break-up that these deposits are of the Kupfer- Exposures of the Coates Lake (e.g., Colpron et al. 2002; Li et al. schiefer-type (Hitzman et al. 2005). Group are restricted to the central part 2007). Ore mineralization in the district is of the Mackenzie Mountains and this At least 25 Cu (± Ag) occur- believed to be the result of fluid mobi- unit is thickest at Coates Lake (Fig. 4; rences are recognized (Fig. 4), of lization in an actively extending basin Aitken 1977; Jefferson and Ruelle which the deposit at Coates Lake is the (Fig. 6; Jefferson and Ruelle 1986; 1986; Colpron and Jefferson 1998; Jef- most significant. Historic resource esti- Chartrand et al. 1989), a concept that is ferson and Colpron 1998). In the mates suggest that it contains 33.6 mil- supported by sedimentary and ore tex- northern Mackenzie Mountains, the lion tonnes grading 3.9% Cu and 9 g/t tures, which suggest that mineralization succession pinches out rapidly and may Ag (Table 1; Hitzman et al. 2005). A took place during very early diagenesis have been eroded prior to deposition thorough review of the deposit geolo- (Jefferson and Ruelle 1986; Chartrand of the overlying Rapitan Group; scat- gy is provided by Chartrand and et al. 1989). Copper and associated tered remnants are found as far north Brown (1985), Jefferson and Ruelle metals were liberated by oxidation of as 64º45’ N (Fig. 4; Eisbacher 1981; (1986), and Chartrand et al. (1989). metals present in aquifer rocks, trans- Jefferson and Parrish 1989; Martel et The Jay prospect to the north is cur- ported in either compaction-derived or al. 2011). South of Coates Lake, the rently the second-most-significant meteoric, recharge-related chloride Coates Lake Group may be present in deposit, with a historic resource esti- brines through sulphate-bearing red- the subsurface, but its extent is mate of 1.2 million tonnes at 2.7% Cu beds, which then interacted with a unknown. Thickness and lithofacies (Hitzman et al. 2005). reducing interface to precipitate sul- patterns in the Coates Lake Group Very low-grade disseminated phides (Fig. 6; Chartrand et al. 1989; define a series of depositional embay- copper sulphide mineralization is wide- Brown 2005; Hitzman et al. 2005). ments (Fig. 4; Jefferson 1983; Jefferson spread, but the most noteworthy cop- This interface is the Transition Zone and Parrish 1989) caused by syn-depo- per occurrences are generally between the Redstone River and Cop- 48

A RG B

TZ CCF

RRF

Jp Hem

Sph

E Qtz

10 cm F

Po + Sch

G Aplite

limestone skarn

Figure 5. A) Exposure of the Coates Lake Group at Fortress Mountain in the Keele River embayment (see Fig. 4). View is northwest. CCF – Coppercap Formation; RG – Rapitan Group; RRF – Redstone River Formation; TZ – Transition Zone. Sig- nificant copper concentrations are generally restricted to the Transition Zone. B) Hand sample of nodular iron formation from the Rapitan iron formation in the northwestern Mackenzie Mountains. Nodules are chert and jasper with minor carbonate (Jp) and groundmass is laminated hematite (Hem). Tip of scribe, (bottom left of the photo), is 0.5 cm long. C) Mineralized drill core from the Howard’s Pass region. Core includes shale with 15% combined Zn–Pb. D) Sphalerite (Sph) and quartz (Qtz) cement in breccia at the Gayna River Zn–Pb deposit (photograph courtesy of R.J. Sharp). E) Zn-Pb mineralized boulder adjacent to the Prairie Creek Zn–Pb–Ag deposit. F) Skarn-related tungsten in massive pyrrhotite-scheelite (Po+Sch) at the Cantung Mine. Aplite dyke cuts, but is associated with the mineralization. G) Vanadium-rich green beryl (emerald) from the Lened emerald prospect. GEOSCIENCE CANADA Volume 40 2013 49

interbedded tuff from correlated rocks in Yukon (Macdonald et al. 2010). On a grand scale, these glacial marine rocks are associated with the contested Sturtian snowball Earth episode (e.g., Hoffman and Schrag 2002; Young 2002; Eyles and Januszczak 2004; Har- land 2007; Macdonald et al. 2010), the nature of which has been questioned as the result of recent radiometric age- dating (e.g., Lund et al. 2003; Kendall et al. 2006; Azmy et al. 2008). The Rapitan Group consists Figure 6. A) Schematic illustration of the development of red-bed-associated Cu of three formations. Diamictite of the mineralization. Modified after Brown (2005) with Coates Lake Group stratigraphy Mount Berg Formation is overlain by added from Jefferson and Ruelle (1986). B) Mineral zonation in the Transition the Sayunei Formation, a dominantly Zone between the Redstone River and Coppercap Formations at the Coates Lake maroon-weathering siltstone with less- deposit, modified after Jefferson and Ruelle (1986). er conglomerate, sandstone, and diamictite. The uppermost Shezal For- percap Formations, and an upward cal constraints on the Zambian Cop- mation is dominated by green-weather- zoning from copper-rich to copper- perbelt, and possible constraints pre- ing (with lesser maroon) diamictite poor ore minerals indicates sub-vertical sented in this study, indicate that it may (Fig. 3; Eisbacher 1981; Yeo 1981, fluid flow (Fig. 6B; Jefferson and be ca. 50–100 million years older than 1986; Klein and Beukes 1993). Eis- Ruelle 1986). The copper source is the Coates Lake Group (Johnson et al. bacher (1981), Klein and Beukes suggested by Chartrand et al. (1989) to 2007). (1993), and Hoffman and Halverson be the now red and oxidized evaporitic (2011) place the iron formation at the beds of the Redstone River Formation, Stratiform Iron Formation top of the Sayunei Formation (Fig. or the volcaniclastic conglomerates of In the MSM, stratiform iron deposits 3A), whereas Yeo (1981, 1986) and the underlying Thundercloud Forma- consist of hematite-jasper layers (Fig. Baldwin et al. (2012) place this unit tion. It is likely that the underlying 5B; e.g., Clout and Simonson 2005; predominantly within the Shezal For- “Little Dal basalt” (Dudás and Lust- Bekker et al. 2010) within the Neopro- mation. It is possible that the thick werk 1997) provided most of the cop- terozoic Rapitan Group, a glacial- iron formation in the northern per, which was either leached directly marine sedimentary succession near Mackenzie Mountains may not be from the basalt, or liberated from vol- the base of the Windermere Super- stratigraphically equivalent to other, canic detritus in overlying units (e.g., group (Fig. 3A; Eisbacher 1978, 1981; thinner iron-formation exposures far- Thundercloud Formation; Figs. 3A and Yeo 1981, 1986; Klein and Beukes ther south (Fig. 7) within the Sayunei 6A). 1993; Hoffman and Halverson 2011; Formation. Numerous red-bed or Kupfer- Hoffman et al. 2011; Baldwin et al. Although some iron forma- schiefer-type copper deposits are 2012). The Rapitan Group uncon- tion is locally present along the strike known globally (Hitzman et al. 2005), formably overlies either the Coates length of the exposed Rapitan Group but North American deposits that are Lake Group, or Little Dal Group and (Fig. 7; Eisbacher 1981; Yeo 1986; temporal equivalents of the Coates was deposited after 750 Ma, the age of Klein and Beukes 1993; Hoffman and Lake Group copper deposits remain a granitic dropstone in tillite (Ross and Halverson 2011; Baldwin et al. 2012), unrecognized. On a global scale, the Villeneuve 1997) and prior to 685 Ma, the thickest and most exciting expo- most similar occurrence may be the deduced by correlation to glacial equiv- sure, from a mineral deposit perspec- Zambian Copperbelt (e.g., Hitzman et alents in Idaho (Lund et al. 2003; Fan- tive, is located in the very northwest al. 2005). This copper belt is Neopro- ning and Link 2004). Park (1997) used part of the Mackenzie Mountains in terozoic, has a similar rift-like environ- paleomagnetic poles and ages of the both Yukon and NWT (Fig. 7), in the ment of deposition and mineralization, Franklin Sills to indicate deposition at Cranswick River–Iron Creek sub-basin. and is overlain by glaciogenic rocks low paleolatitudes at ca. 725 Ma for the In this area, the iron formation is (e.g., Hitzman et al. 2005; Selley et al. Rapitan Group. Using regional correla- exposed over a strike length of 40 km, 2005). A recent paleo-reconstruction tions with the Shaler Supergroup, with thicknesses up to 100 m (Yeo of Rodinia by Evans (2009), an alter- Young (1992) suggested that the iron 1986; Klein and Beukes 1993), and is native to that of Li et al. (2007), places formation is younger than 723 Ma referred to as ‘Crest-IF’, ‘Rapitan iron Africa adjacent to northwestern Lau- (also see Rainbird et al. 1996), which is formation’, or the ‘Snake River rentia at 780 Ma; according to this supported by U–Pb zircon ages of deposit’. The iron formation is com- model, the Zambian Copperbelt may interbedded tuffs and dropstones in posed of rhythmically bedded hematite have formed adjacent to the Coates correlative strata in Idaho (<717 Ma; containing chert-jasper nodules (Fig. Lake Group, on the opposite side of a >685 Ma; Lund et al. 2003; Fanning 5B) with lesser interbedded and band- rift. Conversely, recent geochronologi- and Link 2004) and a ca. 716 Ma ed hematite-jasper (i.e., banded iron 50

Figure 7. Distribution and location of the Neoproterozoic Rapitan Group and associated Rapitan iron formation in the hanging wall of the Plateau fault. Note that the thick and extensive iron formation is restricted to the northwestern part of the mountains. Inset map shows the outcrop extent of the iron formation in the Rapitan Group (after Klein and Beukes 1993). Geographical abbreviations are in Figure 2. GEOSCIENCE CANADA Volume 40 2013 51 formation). Sedimentological and geochemical data were used by Yeo (1986) to attribute the source of iron to rift- related hydrothermal plumes. That study suggested that, although glaciers were present, deposition of the iron formation was not related to glaciation (Fig. 8A). This view is supported by Young (2002) who pointed out that the thick glacial deposits of the Shezal Formation overlie the iron formation. Klein and Beukes (1993), on the basis Figure 8. Schematic illustrations of two competing models for the evolution of of Eu and other rare-earth elements, the Rapitan iron formation. A) The iron and its deposition are related to basinal trace elements, and stable isotope data rifting where glacial cover is coincident with, but not the cause of iron formation. inferred deposition of the Rapitan iron Diagram developed using information in Yeo (1986) and Young (2002). B) Iron formation in water chemically more build-up in an ice-covered, reducing ocean during the Sturtian snowball Earth similar to modern ocean water, than episode. Iron deposition occurred during glacial retreat and ocean oxygenation. was the case for earlier Proterozoic and Modified after Klein and Beukes (1993). See text for discussion. Archean iron formations (Klein and Beukes 1993; Klein and Ladeira 2004; the source of iron and its mechanism ford and Orchard 1983; Goodfellow Klein 2005). This suggests that of deposition may require further 2007), and the Late Devonian MacMil- although rift-related hydrothermal study. lan Pass district that hosts the Tom and plumes may have been the source of The Crest iron formation has Jason deposits (Fig. 9; Ansdell et al. the iron, the iron was concentrated and a drilled historical resource estimate of 1989; Turner 1991; Gordey and Ander- then diluted in ocean water due to sub- 5.6 billion tonnes of ~47% Fe (Iron son 1993; Goodfellow 2007; Goodfel- glacial anoxic conditions during the Creek area, Yukon; Fig. 7; Table 1), low and Lydon 2007; Fernandes 2011). Sturtian snowball Earth (Fig. 8B). Cou- with a regional resource estimated at The Howard’s Pass deposits pled with sedimentological insights, >10 billion tonnes (Gross 1970). This are hosted by the Early Silurian Road Klein and Beukes (1993) suggest that iron deposit is probably the largest in River Group (Norford and Orchard the iron was then precipitated during western North America and the largest 1983; Figs. 5C and 9), a regionally glacial retreat and subsequent oxygena- undeveloped deposit in North America extensive succession of shale, chert, tion of the ocean (Fig. 8B). A more (Gross 1970; Klemic 1970). It remains and minor limestone. These Selwyn complex mechanism of iron formation uneconomic to exploit due to the cur- Basin strata are deeper water succes- precipitation is suggested by Baldwin rent lack of infrastructure in the sions than the laterally equivalent slope et al. (2012). Using REE+Y and Mo–U region. Possible analogues to the Rapi- and platform facies of the Mackenzie geochemical constraints and bedrock tan iron formation are summarized by Platform to the east (Gordey and observations they suggest that the iron Yeo (1986), Young (2002), Klein Anderson 1993; Goodfellow 2007; was derived from glacier-related, ter- (2005), and Hoffman et al. (2011). Martel et al. 2011). Howard’s Pass con- rigenous sediment rather than from tains an overall drill-indicated resource hydrothermal fluids. In this model dis- SEDEX Zn–Pb (± Ag, Ba) of 185.57 Mt @ 5.20 Zn% and 1.79% solved iron created increasingly ferrugi- Stratiform sedimentary exhalative Pb from >10 individual deposits (Sel- nous conditions in an ice-capped semi- (SEDEX; Leach et al. 2005) Zn–Pb wyn Chihong Mining Ltd. 2012; Table restricted basin. Iron precipitation deposits are present in Cambro–Siluri- 1). The ore mineralogy is mostly spha- occurred during glacial retreat and was an and Devonian siliciclastic rocks lerite and galena with little to no iron related to upwelling of dissolved iron, (shale) in the Selwyn Basin (Fig. 9). sulphide. The ore mineralogy and geol- which interacted with the top layer of These SEDEX deposits have been ogy suggest that the Howard’s Pass progressively oxygenated waters (Bald- thoroughly reviewed by Leach et al. deposit was formed in a hydrothermal win et al. 2012). We have observed (2005), Goodfellow (2007), and Good- vent-distal mineralizing environment dropstones in the iron formation as fellow and Lydon (2007), and are only (Fig. 10A; Goodfellow 2007; Goodfel- well as in an underlying glacially- briefly discussed here. In addition to low and Lydon 2007). Most of the derived diamictite and the overlying these reviews, Fernandes (2011) pres- well-defined deposits of this district Shezal tillite. This likely indicates a ents new data on barite-rich SEDEX are in the Yukon but straddle the bor- more dynamic ice environment of gla- deposits in this region. Three tempo- der with the Northwest Territories; the cial retreat and advance, including rally distinct SEDEX districts are rec- laterally equivalent deposits in the meltout from calved icebergs and pos- ognized; the Cambrian-hosted Anvil Northwest Territories are relatively sibly multiple periods of open water district in Yukon (Pipage 2004; not dis- under explored. The only larger and water column overturning. Overall, cussed further), the Early Silurian SEDEX deposits in North America it seems unquestionable that the iron Howard’s Pass district (Godwin and are the past-producing Mesoprotero- formation was related to glaciation, but Sinclair 1982; Godwin et al. 1982; Nor- zoic Sullivan deposit in British Colum- 52

132°W 130°W 66°N

ARR 128°W

MRnm GR

MtR 65°N 126°Wnm

NWT YT

KR 64°N 124°W

MP SB RTR nm 0#Tom/ Jason 63°N 0# 0#

0#0#0#0#Howard's Pass 0#0#0#0#0# 0# NNR 0#0#0#0#0# 0# 0# 0# 0# MR 0# 122°W 0#0# 62°N 0#0#0# 0# 0#0#0#0#0# nm nm SNR

0#0# MP 0# SB

LR nm 0# 0# 61°N 0# 0# 0#0# NWT YT

Geology Road River Group Other nm Mineralization nm Community 0 20406080100 0' SEDEX Canol Heritage Trail Kilometres

Figure 9. Distribution of the Ordovician to Devonian Road River Group in the Selwyn Basin and associated SEDEX Zn–Pb mineral occurrences (Road River Group shale hosts the Howard’s Pass SEDEX deposit). The Tom and Jason deposits are hosted by Devonian strata in Yukon Territory. MP – Mackenzie Platform; SB – Selwyn Basin; all other geographical abbreviations are as in Figure 2. GEOSCIENCE CANADA Volume 40 2013 53

The SEDEX mineralization is thought to have resulted from mixing of chloride-rich, oxidized, metallifer-

ous fluids with H2S-bearing (reducing) fluids in both vent-distal (Howard’s Pass; vent not yet discovered) and vent-proximal settings (MacMillan Pass; Fig. 10; Turner 1991; Goodfellow 2007). Based on stable and radiogenic isotopic constraints, the ore-bearing fluids were likely derived from fluids circulating through North American basement (Godwin and Sinclair 1982; Goodfellow 2007; see radiogenic Pb data in Fig. 11 for SEDEX deposits) that were focused and discharged along syngenetic extensional faults, and were vented into the water column (Fig. 10; Bailes et al. 1986; McClay and Bidwell 1986; Goodfellow and Rhodes 1991; Turner 1991; Goodfellow 2007; Good- fellow and Lydon 2007). The overall tectonic setting for SEDEX deposits in the Selwyn Basin is described as a reac- tivated rift for the Early Silurian Howard’s Pass vent-distal Zn–Pb and a back-arc setting for the Late Devonian MacMillan Pass vent-proximal Zn–Pb–Ag-Ba deposits (Nelson et al. 2002, 2006; Goodfellow and Lydon 2007). Although the Howard’s Pass deposits have many features similar to Figure 10. Generalized models of A) vent-distal SEDEX mineralization in the other large SEDEX deposits (see Howard’s Pass region and B) vent-proximal SEDEX mineralization at Tom and Leach et al. 2005; Goodfellow and Jason deposits in the MacMillan Pass region. Modified after Goodfellow and Lydon Lydon 2007), there does not appear to (2007). be a temporal relationship with any of these globally (see Table 1 in Goodfel- bia and the producing Mississippian Jason deposits 14.1 Mt @ 7.1% Zn, low and Lydon 2007). The MacMillan Red Dog deposit in Alaska (Goodfel- 6.6% Pb, and 80 g/tonne Ag (Bailes et Pass deposit has similarities consistent low and Lydon 2007). Howard’s Pass al. 1986). Unlike Howard’s Pass, this with typical stratiform Zn–Pb–Ba currently is the single largest, undevel- area does contain significant Ba and Ag deposits (e.g., Ansdell et al. 1989) and oped zinc district in the world and is (Bailes et al. 1986; McClay and Bidwell are temporally similar to other Ba-rich second only to Red Dog in total zinc 1986; Ansdell et al. 1989; Goodfellow Devonian–Mississippian prospects in (e.g., Leach et al. 2005). and Rhodes 1991; Turner 1991). Tom the Selwyn Basin (e.g., Fernandes The Tom and Jason SEDEX and Jason contain tetrahedrite (carrying 2011), the Cirque SEDEX deposit in deposits are hosted in the Devonian Ag) in addition to extensive pyrite, northern British Columbia (Goodfel- Earn Group in the MacMillan Pass dis- pyrrhotite, galena, sphalerite, and lesser low and Lydon 2007), and possibly to trict near the Yukon – NWT border arsenopyrite, a result of a complex and the Pine Point and Robb Lake Missis- (Fig. 9; Bailes et al. 1986; McClay and laterally zoned vent facies mineralizing sippi Valley-type (MVT) deposits (Nel- Bidwell 1986; Ansdell et al. 1989; environment (Fig. 10B; Bailes et al. son et al. 2002). Previous studies imply Goodfellow and Rhodes 1991; Turner 1986; McClay and Bidwell 1986), ver- that the Selwyn Basin-hosted SEDEX 1991; Gordey and Anderson 1993; sus the vent distal environment for and Mackenzie Platform-hosted Zn–Pb Goodfellow and Lydon 2007). This Howard’s Pass (Goodfellow and Lydon deposits may have formed contempo- region appears to be significantly less 2007). At Tom and Jason, the mineral- raneously (e.g., Nelson et al. 2002). enriched in Zn and Pb than Howard’s ization more distal from the vent con- Precise age data are not available for Pass; historical resource estimates for tains less Pb–Zn–Ag, but higher Ba in most of the carbonate-hosted Zn–Pb the Tom deposit indicate 15.7 Mt @ interbedded barite-chert beds (e.g., occurrences in the MSM area, and 7% Zn, 4.6% Pb, and 49 g/tonne Ag Bailes et al. 1986; McClay and Bidwell therefore it is not currently possible to (McClay and Bidwell 1986), and for the 1986; Turner 1991). evaluate this concept. 54

are Gayna River, Bear–Twit, Prairie Creek, and potentially Wrigley–Lou (Figs. 5D-E and 12; Heal 1976). Gayna River is in the northern Mackenzie Mountains (Fig. 12), and is character- ized by breccia-cemented, gallium-rich sphalerite (Fig. 5D) with lesser pyrite and hematite, hosted in the Neopro- terozoic Little Dal Group (Hewton 1982; Dewing et al. 2006; Wallace 2009). An historical resource estimate of 50 million tonnes with over 5% combined Zn–Pb is reported by Hew- ton (1982; Table 1), although the overall tonnage is probably exaggerated (Wallace 2009). The Bear–Twit prospect, southeast of Gayna River (Fig. 12), contains Zn–Pb–Cu–Ag (sphalerite, galena, tetrahedrite) in veins that cross-cut Paleozoic strata (Dewing et al. 2006). Bear–Twit has an historical resource estimate of 7 million tonnes @ 5.4% Zn, 2.6% Pb, and 17.1 g/t Ag, although the overall tonnage may be over-estimated (Dewing et al. 2006). Prairie Creek, in the southern Macken- zie Mountains (Fig. 12), contains stratabound, sphalerite-galena-bearing ore (Fig. 5E) hosted in the Ordovician Whittaker Formation as well as late, Ag-rich, Pb–Zn veins that crosscut early Paleozoic carbonate rocks and shale (Paradis 2007). Canadian Zinc Figure 11. Lead isotopic data from the Mackenzie Mountains. A) 206Pb/204Pb versus Corporation is in the process of devel- 207Pb/204Pb. B) 206Pb/204Pb versus 208Pb/204Pb. The “Cordilleran Carbonate-lead” oping a mine plan for the Prairie Creek region is derived from Nelson et al. (2002) and Paradis et al. (2006); the Pine Point Zn–Pb–Ag deposit, and report a meas- region is from Godwin et al. (1982) and data in Paradis et al. (2006); Cretaceous ured resource of 5.8 million tonnes @ pluton K-feldspar data are from Rasmussen et al. (2007); Devonian SEDEX, 20% Zn–Pb and 212 g/t Ag (Table 1). Ordo-Silurian SEDEX, and Cambrian SEDEX fields from Godwin and Sinclair Comparisons among the (1982), Godwin et al. (1982), Cousens (2007), and Paradis (2007); the shale curve is deposits and prospects in the MSM from Godwin and Sinclair (1982); and the Stacey & Kramers curve is from Stacey area are difficult owing to differences and Kramers (1975). All other data sources are in the legend. Ages on curves are in in host-rock age (Fig. 3B), mineralogy, Ma. Plotted data from Godwin et al. (1982) includes only galena data from and alteration. There is an array of dif- prospects in the Mackenzie Mountains. ferent mineralization styles, even within individual occurrences (cf. Nelson et al. Carbonate-hosted Zn–Pb (± Cu, Ag, Carrière and Sangster 1999; Gleeson 2002; Lund 2008). An emerging Ba, Sb, Ga) 2006; Paradis 2007; Wallace 2009). hypothesis is that some of the carbon- Over 230 Zn–Pb (± Cu, Ag, Ba, Sb, Such deposits are referred to here as ate-hosted Zn–Pb occurrences, such as Ga) prospects and deposits are present ‘carbonate-hosted’ rather than MVT Gayna River, were influenced by north- throughout the MSM area in the Paleo- due to these elevated temperatures of east-trending faults (present co-ordi- zoic Mackenzie Platform that formed formation (cf. Hewton 1982; Nelson et nates) that were active during deposi- east of the Selwyn Basin (Fig. 12; Mar- al. 2002; Goodfellow 2007; Leach et al. tion of Neoproterozoic strata (Aitken tel et al. 2011). The mineralogy within 2005; Paradis et al. 2007; Lund 2008). and Cook 1974; Turner and Long this ‘Mackenzie Mountains Zinc Dis- As Paradis (2007) and Wallace (2009) 2008. Later fluids may have used these trict’ commonly includes sphalerite, point out, however, many other aspects structures to access favourable struc- smithsonite, and galena, with variable of these mineralized zones are consis- tural or lithostratigraphic depot-zones amounts of barite and copper-sul- tent with the MVT classification (Turner and Long 2008). This relation- phide/sulphosalts. Fluid-inclusion data (Leach et al. 2005; Paradis et al. 2007). ship may be similar to that of the Pine indicate temperatures of formation The key carbonate-hosted, Point MVT – MacDonald Fault rela- from 160° to >200°C (Fraser 1996; base-metal deposits in the MSM area tionship to the east (Hannigan 2007). GEOSCIENCE CANADA Volume 40 2013 55

Figure 12. Geographic distribution of Paleozoic strata and Mackenzie Platform-hosted Zn–Pb (+ base-metal) occurrences. Note that some prospects near the platform-basin boundary may be related to the SEDEX occurrences in Figure 8. MP – Mackenzie Platform; SB – Selwyn Basin; all other geographical abbreviations are as in Figure 2. 56

In contrast, the Prairie Creek 1998; Dewing et al. 2006; Wallace Prairie Creek data, or between them deposit contains a stratabound Zn–Pb 2009). However, deformation may dif- (Fig. 11A). The galena Pb isotopic data component, hosted by the Ordovi- fer in timing from one deposit to from the Wrigley–Lou prospects are cian–Silurian Whittaker Formation, another and may have taken place in a too radiogenic to plot on Figure 11 overprinted by both MVT-like style few pulses over a ~100 m.y. interval (Heal 1976), but fall within the and later, Ag-rich vein style mineraliza- (e.g., Morris and Nesbitt 1998; Mair et Cordilleran carbonate-lead trend. tion (Fraser 1996; Paradis 2007). Prairie al. 2006a; Martel et al. 2011). Other Notably, the signature from the Pine Creek, therefore, embodies several of workers have suggested a mineraliza- Point MVT deposit is significantly less the various carbonate-hosted Zn–Pb tion event during the Devonian to Mis- radiogenic than that of lead from the types present throughout the MSM sissippian (e.g., Nelson et al. 2002), carbonate-hosted Zn–Pb prospects in area. The MVT-like mineralization at possibly related to SEDEX deposits in the MSM area, likely indicating distinct Prairie Creek and the main stage ore the Selwyn Basin (Goodfellow 2007), and separate mineralizing events, fluid minerals at Gayna River do, however, which Nelson et al. (2002, 2006) sug- pathways, and/or fluid sources (Fig. have very similar fluid chemistries gest took place in a distal back-arc set- 11; Hannigan 2007). (Wallace 2009). The common threads ting. The precise timing and regional Regional relationships and Pb within this diverse group of prospects relationships are outstanding problems isotopic data suggest that a minimum and deposits are a similarity in Zn–Pb in linking deposit types, a subject also of two generations, but more likely metal budget (± Ba and other base raised by Hannigan (2007) with respect three or four, of carbonate-hosted metals), and their location in Neopro- to the Pine Point MVT deposit. Zn–Pb (+ other base-metal) deposits terozoic or Paleozoic carbonate rocks. Radiogenic Pb isotope data are present in the MSM area. These The depositional setting for the Paleo- from galena in a number of carbonate- include: (1) stratabound ore at Prairie zoic carbonate rocks was a passive hosted Zn–Pb occurrences shed some Creek that is similar to, and possibly margin (Mackenzie Platform), with the light on the evolution of these deposits related to, the Cambrian–Mississippian Selwyn Basin marking the transition to when compared with the shale curve SEDEX type in the Selwyn Basin to the proto-Pacific Ocean and peri-cra- for SEDEX deposits (Fig. 11: Godwin the west (Figs. 10 and 12); (2) vein and tonic terranes to the west. The tectonic et al. 1982; Godwin and Sinclair 1982; breccia-hosted Zn–Pb deposits, such as environment of mineralization, howev- Morrow and Cumming 1982; Fraser those at Gayna River and Bear–Twit, er, is more complex, as discussed 1996; Gleeson et al. 2007; Paradis which may or may not be related to below. 2007). The Pb isotopic data indicate a SEDEX mineralization (Figs. 10 and The main difficulty in linking range of mineralizing styles. At Prairie 12); (3) possible MVT deposits, and; these diverse deposits to a tectonic Creek, the Pb isotopic data mimics (4) ca. 250 to 60 Ma, vein-hosted, Ag- ‘event’ is the lack of age constraints lead from Silurian through Devonian Zn–Pb deposits, such as those at (cf. Nelson et al. 2002; Goodfellow SEDEX deposits (Fig. 11). Paradis Prairie Creek (Figs. 10 and 12). 2007; Lund 2008), and controversy (2007) used this to indicate that the persists over the timing of mineraliza- stratabound deposits at Prairie Creek Intrusion-Related Deposits tion at many of the occurrences. Gen- formed simultaneously with SEDEX At least 100 mineral occurrences in the erally, the arguments revolve around deposits in the Selwyn Basin. The study area have been shown to be Cambrian to Mississippian versus Cre- homogeneity is taken to infer either a directly related to intermediate to fel- taceous–Tertiary metal emplacement, similar fluid source, or significant mix- sic, ca. 100 to 90 Ma (mid-Cretaceous) or possibly both (also see Fraser 1996; ing of Pb (Morrow and Cumming, plutons and batholiths that are wide- Morris and Nesbitt 1998; Nelson et al. 1982). Data in Morrow and Cumming spread throughout the northern 2002; Paradis et al. 2006; Paradis 2007; (1982), Fraser (1996), and Paradis Cordillera (Lang 2000; Selby et al. Wallace 2009). Considering the ages of (2007) have been used to suggest that 2003; Hart et al. 2004a, b; Hart 2007; the sedimentary units that host these the Ag-bearing veins at Prairie Creek Rasmussen et al. 2007). In particular, Zn–Pb deposits, their mineralizing are related to Cretaceous deformation tungsten skarn (e.g., Meinert et al. events must be younger than Cambrian (referred to as the ‘Cadillac’ deposit), 2005) has historically been the most for Gayna River and a number of although the lead isotopic data collec- significant source of mining-generated other occurrences in the northern tively cross the shale curve suggesting revenue in this area (e.g., Dick and Mackenzie Mountains, younger than a Triassic age (Fig. 11). In contrast, Hodgson 1982; Hart et al. 2004b). The Silurian for Prairie Creek, and younger data from Gayna River (Gleeson et al. plutons were emplaced in the Selwyn than Devonian for a number of other 2007) do not match either style of Basin area near a lithological transition prospects. Field relationships indicate mineralization at Prairie Creek, and to shallower-water platformal, sedi- that the deposits are structurally con- may represent the less radiogenic end- mentary rocks (Mackenzie Platform; strained, generally as breccias or veins. member on a mixing line with the Fig. 13; e.g., Gordey and Anderson Cretaceous–Tertiary deformation pro- more radiogenic, previously defined, 1993); contiguous with a belt of plu- vides a minimum age for carbonate- “Cordilleran carbonate-lead” trend tons that extends from central Alaska hosted Pb–Zn, and some of the other (Fig. 11A; Nelson et al. 2002; Paradis et through to British Columbia (Hart et base-metal occurrences may also be al. 2006). Isotopic Pb data on galena al. 2004a, b; Hart 2007). These intru- related to this event (Godwin et al. from a variety of other prospects fall sions are mainly high-K, calc-alkaline 1982; Fraser 1996; Morris and Nesbitt within the range of Gayna River or to alkaline, biotite ± hornblende ± GEOSCIENCE CANADA Volume 40 2013 57

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GG GGGGG GGG GGG GG G GGG G LR GG G G nm GGG 61°N Cretaceous Plutonic Suites G Tay River - Tungsten G

Tomb ston e NWT Tungsten YT Undifferentiated Mineralization Other nm G Intrusion-related Skarn Mineralization nm Community 0 20406080100 Intrusion-hosted Rare Element and ^_ Gemstone Mineralization Canol Heritage Trail Kilometres

Figure 13. Intrusion-related deposits associated with the Cretaceous Tombstone-Tungsten plutonic suite. Plutonic suites are modified after Rasmussen et al. (2007). Precious mineral prospects associated with plutons within the Yukon Territory are not shown. Geographical abbreviations are as in Figure 2. 58 clinopyroxene ± muscovite-bearing granitoids comprising mainly granitic (senso stricto) to granodioritic compositions, with minor diorite to quartz diorite dykes. These are separated into four geographically, temporally, petro- logically, and metallogenically distinct suites. These subdivisions are the older Tay River suite (99–96 Ma), the Tung- sten suite (98–96 Ma), the Mayo suite (97–93 Ma), and the Tombstone suite (93–89 Ma; Lang 2000; Hart et al. 2004a, b; Rasmussen et al. 2007, 2010). Most of the Tombstone suite intrusions, and many of the Mayo suite intrusions, follow an alkalic to sub- alkalic, monzonitic to monzogranitic compositional trend that contrasts with the dioritic-granodioritic-granitic trend exhibited by the majority of ‘mid’-Cre- taceous plutons in the MSM area (Ras- mussen et al. 2010). Regional geologic reconstructions (Nelson and Colpron 2007) and geochemical profiles (e.g., Figure 14. Schematic illustration incorporating all intrusion-related deposit styles in Lang 2000; Hart et al. 2004b; Ras- the Mackenzie and eastern Selwyn Mountains. Adapted from Lang et al. (2000). mussen et al. 2007) indicate that the magmatism occurred in an area under- proximal to, and typically genetically Intrusion-Related Skarn Deposits going dextral transpression, with local- related with, mainly the Tungsten suite Currently and historically, the most ized extension, hundreds of kilometres and highly evolved phases of the Tay economically important deposits in the inboard of a post-collisional continen- River suite. These skarns are mostly study area are intrusion-related, tung- tal margin (Hart et al. 2004b; Ras- tungsten-rich (± minor Cu and/or Zn, sten-bearing skarns (± Cu, Zn, Mo, mussen et al. 2010). The overall trend Mo, Bi, and/or Au; Dick and Hodgson Au, Bi; Fig. 13; Dawson and Dick of the mid-Cretaceous plutonic belts is 1982; Bowman et al. 1985; Selby et al. 1978; Dick and Hodgson 1982; Daw- thought to parallel the North American 2003; Hart et al. 2004a, b; Rasmussen son 1996; Hart et al. 2004a). Two Neoproterozoic rifted margin, the et al. 2007; Yuvan et al. 2007; Ras- exemplary examples are: 1) The past- Paleozoic passive margin, and perhaps mussen et al. 2010), although Au-(Ag)-, producing Cantung Mine; and 2) Mac- the transition from the Mackenzie Plat- or Sb-rich skarns are also associated tung, North America’s second largest form to the Selwyn Basin (Cecile et al. with some Mayo and Tombstone suite tungsten deposit; Sisson Brook, New 1997; Hart et al. 2004b; Hart 2007). intrusions. More distal base metal-rich Brunswick, is recognized as Canada’s The distinctive metal budgets of each deposits (e.g., Cu, Zn, Pb, Ag, Au) largest tungsten deposit and its devel- plutonic suite, as defined by Hart et al. associated with all of the intrusive opment will surpass Cantung as the (2004b) and Rasmussen et al. (2007) suites occur in the form of replace- largest tungsten producer in North are interpreted to reflect their magmat- ments or mantos and veins (Lang America. Cantung has been an “on ic sources. Magmatic segregation and 2000; Hart et al. 2004a; Rasmussen et again/off again” producer of tungsten differentiation processes may have also al. 2007). The second category of since the early 1960s and has an indi- played a role in the formation of tung- deposits associated with mid-Creta- cated resource of 2.9 million tonnes @ sten skarns (Rasmussen et al. 2011). ceous plutons consists of pegmatite 1.2% WO3 (Table 1; Intrusions in the MSM area and quartz vein-hosted gemstones http://www.natungsten.com). Mactung belong to the Tay River suite and the (emerald, Marshall et al. 2004; Tomb- is currently in the feasibility stages and southeast Tombstone–Tungsten belt stone suite-hosted, semi-precious tour- has an indicated resource of 33 million (TTB) that comprises the Tungsten, maline, Ercit et al. 2003). Pegmatite- tonnes @ 0.88 WO3 (Table 1; Mayo, and Tombstone suites (Fig. 13; hosted, rare-element deposits in the http://www.natungsten.com). Lang 2000; Selby et al. 2003; Hart et al. Little Nahanni Pegmatite Group (Li, The Cantung and Mactung 2004a, b; Rasmussen et al. 2007, 2010). Cs, Ta, Nb, and Sn; Figs. 13 and 14) deposits are both hosted in Lower The predominant forms of intrusion- are included here, although no direct Cambrian, calcareous strata proximal related deposits associated with these link with the mid-Cretaceous plutons to small, slightly peraluminous, monzo- plutonic rocks are divided into two has been established and the peg- granitic intrusions of the Tungsten broad categories (Figs. 13 and 14; Hart matites may be younger (Groat et al. suite (Dick and Hodgson 1982; Math- et al. 2004a, b). The first group con- 2003; Barnes et al. 2007). ieson and Clark 1984; Bowman et al. sists of skarn-related deposits that are 1985; Gerstner et al. 1989; Selby et al. GEOSCIENCE CANADA Volume 40 2013 59

2003; Hart et al. 2004a, b; Rasmussen indicate mineralization occurred at T = western Sierra Nevada (e.g., the Pine et al. 2007, 2011; Yuvan et al. 2007). 400 to 540°C and P = 2 to 3.8 kbar Creek Mine; Newberry 1982; Brown et Scheelite is the most important tung- (greater than 6 km depth; Marshall et al. 1985). Other possible correlatives sten mineral, accompanied by varying al. 2003). Yuvan et al. (2007) conclude include ca. 95 to 90 Ma intrusions with amounts of pyrrhotite, chalcopyrite, that the high-grade quartz-scheelite associated pyrrhotite-rich, Cu-Au-bear- sphalerite, and molybdenite, and traces veins are the distal expression of the ing skarn deposits in the Carlin trend, of bismuthinite and native bismuth mineralized skarn-forming event relat- Nevada (Groff et al. 1997). (Fig. 5F; Rasmussen et al. 2011). The ed to magmatism. scheelite and pyrrhotite are most com- The Mactung deposit, which is Intrusion-hosted, Rare-Element and monly components of the hydrous hosted in limestone, can be divided Gemstone Deposits skarn facies (typically amphibole-rich, into anhydrous (pyroxene–garnet) and Other intrusion-related deposits in the although biotite-rich varieties occur at hydrous (amphibole–biotite–pyrrhotite MSM area (Figs. 13 and 14) include Cantung). These minerals also occur ± scheelite) skarn types (Dick and pegmatite-hosted, rare-element (Li, Cs, less commonly in the anhydrous skarn Hodgson 1982; Gerstner et al. 1989). and Ta; e.g., Černý et al. 2005) show- facies (garnet–hedenbergite), and local- This deposit is adjacent to a small, ings and vein-hosted, semi-precious ly in high-grade tungsten deposits asso- medium-grained, K-feldspar-phyric, gemstones (beryl and tourmaline; Ercit ciated with coeval aplite dykes or late biotite monzogranite with associated et al. 2003; Marshall et al. 2004; Groat cross-cutting quartz–scheelite veins aplite and pegmatite dykes. Fluid-inclu- et al. 2007). Eighty kilometres north of (Dick and Hodgson 1982; Bowman et sion results from both skarn facies Cantung, the Little Nahanni Pegmatite al. 1985; Gerstner et al. 1989; Hart et indicate that mineralization and anhy- Group is a cluster of over 200, subpar- al. 2004b; Rasmussen et al. 2011). drous alteration began around allel, up to two-metres-wide, pegmatite The ore-bearing skarn at Can- 410–470°C and evolved to a hydrous dykes exposed over an area of 5 by 11 tung Mine is adjacent to a medium- skarn at 360–415°C, between 5 and 10 km (Fig. 13; Groat et al. 2003; Barnes grained, weakly K-feldspar-phyric, km depth (Gerstner et al. 1989). These et al. 2007). U–Pb columbite dating biotite-bearing monzogranite stock that conditions are similar to, although indicates that the pegmatites crystal- underlies the ore zones and has multi- slightly cooler than, the estimates for lized at ca. 81 Ma (Mauthner et al. ple phases of associated aplitic and, Cantung. 1995), 15 m.y. younger than the age of more rarely, pegmatitic dykes (Figs. 5F Based on the criteria of Mein- recognized Cretaceous plutons in the and 14; Rasmussen et al. 2011). Two ert et al. (2005), Cantung and Mactung region (Barnes et al. 2007; Rasmussen types of ore are distinguished: 1) skarn can be considered reduced tungsten et al. 2007). The pegmatites are weakly dominated by a relatively pyrrhotite- skarns (Bowman et al. 1985; Gerstner deformed. K–Ar (mica) and 40Ar/39Ar poor anhydrous pyroxene-garnet et al. 1989), which is consistent with (muscovite) ages indicate they were assemblage in the ‘Open Pit’ orebody; the highly reduced nature of the reheated at ca. 65 Ma (Mauthner et al. this orebody is located on the surface inferred source of mineralizing fluids 1995; Barnes et al. 2007). about 300 metres above the roof of (e.g., the Tungsten plutonic suite; Hart The pegmatites are divided the underlying stock and is cut by high- et al. 2004b), a favourable condition into spodumene-bearing and spo- grade, quartz–scheelite veins (Yuvan et for magmatic tungsten enrichment. dumene-free varieties, the latter having al. 2007); and 2) anhydrous garnet- This also could account for the paucity more abundant lepidolite (Groat et al. hedenbergite skarn, overprinted by a of gold associated with these intru- 2003). Barnes et al. (2007) report up to more pervasive and pyrrhotite-rich, sions, unlike the younger and more 1.4% Li in the pegmatites, with the hydrous, amphibole skarn facies and a oxidized Tombstone suite that has highest concentrations in spodumene- less pervasive biotite ± pyrrhotite been interpreted to have incorporated bearing varieties that have low Ta-Sn skarn in the underground E-Zone ore- significant amounts of enriched, man- values. Cesium concentrations range body, located immediately above the tle-derived melt (Hart et al. 2004b). For from 46–497 ppm (up to 0.05% Cs) roof of the underlying stock (Math- this reason the Tungsten Suite is con- and Ta ranges from 5.3–188 ppm (up ieson and Clark 1984). Fluid inclusion sidered the most likely to contain tung- to 0.019% Ta; Barnes et al. 2007). and stable isotope data on the quartz– sten skarn and associated ore in the Rare-element concentrations suggest scheelite veins from the Open Pit ore- study area (Rasmussen et al. 2007). that the pegmatites were derived from body indicate the ore was deposited at The intrusion-related skarn deposits in evolved crustal melts, similar to eco- temperatures of 400–595°C and pres- the MSM area are coeval with other nomically exploited pegmatites else- sures of 2–4 kbar (about 6–10 km Cretaceous examples in the Cordillera, where (Černý et al. 2005; Barnes et al. depth), from primary fluids of mag- such as the Scheelite Dome deposit in 2007). The Little Nahanni Pegmatite matic origin (up to 90 mol%), with the Yukon (Mair et al. 2006b), and the Group fits the classification of only minor input from a country rock Northern Dancer/Logtung deposit in Li–Cs–Ta pegmatites (Černý et al. to meteoric source (Bowman et al. southern Yukon and northern British 2005; Barnes et al. 2007) in that they 1985; Yuvan et al. 2007). This is con- Columbia (Noble et al. 1984, 1986). are commonly hosted by metasedimen- sistent with mineralogical, fluid inclu- Possible North American correlatives tary rocks, rarely occur in their source sion, stable isotope, and biotite-apatite to Cantung and Mactung include tung- granites, and are generally syn- to post- thermometry data from the under- sten skarn deposits associated with ca. orogenic, filling fractures related to ground ‘E-Zone’ biotite skarn that 94 Ma quartz monzonite plutons in the post-collisional stresses (Černý et al. 60

2005). This is consistent with the Other Deposit Types of which is smoking as a result of regional dynamic setting at ca. 80 Ma, spontaneous combustion (i.e., coal in which localized extension was relat- Coal fires; Tveten 2007). Coal seams up to 6 ed to increased obliquity to NNE-ori- Coal is interbedded in the Carbonifer- m thick are reported, but the majority ented compression in a post-collisional ous Mattson Formation in the south- are 1–2 m thick, with ‘clean coal’ layers setting (e.g., Hart et al. 2004a, b; Mair ern Mackenzie Mountains (Figs. 3A being slightly thinner. The coal seams et al. 2006a; Rasmussen et al. 2007). and 15; Ricketts 1984; Potter et al. are interbedded in a 200 m-thick suc- Semi-precious gemstones 1993; Cameron et al. 1994). The coal cession of Tertiary shale, clay, siltstone, include green beryl (variety: emerald; forms three seams with an average sand, and conglomerate related to allu- Fig. 5E; Marshall et al. 2004; Groat et thickness of 1.5 m (Cameron et al. vial fan formation (see Tveten 2007). al. 2007) and elbaite tourmaline (Figs. 1994) and is described as being sapro- 13 and 14; Ercit et al. 2003). Green pelic, high-bituminous, and inertinite- Placer Gold beryl was discovered in 1997, 75 km and liptinite-rich (Potter et al. 1993). Minor amounts of placer gold have northwest of Cantung, at the Lened The environment of deposition was a been reported in the very southwest skarn deposit (Fig. 13; Marshall et al. lagoonal setting in a prograding delta and southeast of the Mackenzie Moun- 2004). The Lened vanadium-rich beryl with little precipitation in an area of tains (Fig. 15). These occurrences were is hosted within quartz-carbonate veins minimal tectonic activity (Potter et al. investigated by Rasmussen et al. (2006), that formed in conjunction with, 1993; Cameron et al. 1994). Cameron who recognized two styles of placer although they cross-cut, a tungsten– et al. (1994) document a number of gold, based on geography and gold copper mineralized pyroxene–garnet possible global analogues to the Car- grain morphology; ‘Chuck’ and ‘isolat- skarn (Marshall et al. 2004; Groat et al. boniferous coal. ed’ gold types. Both gold types are rel- 2007). The vanadium is interpreted to Cretaceous–Tertiary coal has atively pure, with fineness have been sourced from Devonian been reported from the Mackenzie ([Au/Au+Ag]*1000) ranging from 700 shales in the immediate footwall. Fluid Mountains interior (Ricketts 1984; to 975, in a wide range of grain mor- inclusion and stable isotope data indi- Martel et al. 2011), the southern phologies. Using the Cailleux grain- cate that the fluids responsible for Mackenzie Mountains (Ricketts 1984), flattening index, Rasmussen et al. beryl formation were derived from the north of the Mackenzie Mountains (2006) show that both of these styles proximal, ca. 95 Ma felsic intrusion (Pyle and Jones 2009), and on the east- of placer gold were transported less (Fig. 14; Marshall et al. 2004). A similar ern edge of the Mackenzie Mountains, than 10 km. They speculate that the magmatic origin has been suggested by south of the community of Tulita gold source could either be intrusion- Groat et al. (2002) for emeralds at (Fort Norman Coal Field; Fig. 15; related, or yet undefined Carlin-type Regal Ridge, Yukon (now called Tsa da Ricketts 1984; Dixon 1999; Tveten deposits. Both the recent discoveries of Glisza). 2007). The coal within the Mackenzie Carlin-type gold in the eastern Yukon, Semi-precious, Li–bearing gem Mountains (Fig. 15) forms thin seams and the identification of gold grains in tourmaline is hosted in lithium-rich, (40–50 cm) in laterally discontinuous, stream sediments in the Arctic Red pegmatitic zones in the composite steeply dipping, highly sheared, mud- River watershed to the north (Day et hornblende-bearing granitic to gran- stone-rich, post-Berriasian to Campan- al. 2009) are encouraging that yet- odioritic of the ca. 92 Ma O’Grady ian strata (Martel et al. 2011). It is unidentified gold deposits may be pres- batholith (Fig. 13; Gordey and Ander- described as low-bituminous to semi- ent in the Mackenzie Mountains. son 1993; Ercit et al. 2003; Rasmussen anthracitic (Martel et al. 2011) and, due et al. 2007), interpreted to be part of to the sparse amount preserved, is con- Diamonds and Other Gemstones the Tombstone Suite (Rasmussen et al. sidered non-economic. Sub-bituminous Historical exploration for diamonds in 2007). The gemmy tourmaline is in coal hosted by the Cretaceous Wapiti the MSM area has generally focussed lithium-rich zones and exhibits pink, Formation in the very southernmost on Ordovician alkaline diatremes and red, yellow-brown, and rare fluorine- Mackenzie Mountains (Fig. 15), has an associated volcanic rocks (Godwin and rich green colors; outside these zones historical resource estimate of 240 mil- Price 1986; Goodfellow et al. 1995; the tourmaline is black schorl–dravite lion tonnes (Ricketts 1984). Coal Leslie 2009). Unfortunately, the dia- (Ercit et al. 2003). The host pegmatites deposits on the northern edge of the mond reports in Godwin and Price have a Nb–Y–F signature (Černý et al. Mackenzie Mountains occur as <2 cm- (1986) have not been reproducible. A 2005), in contrast to the Li–Cs–Ta sig- thick seams in Albian strata (Pyle and discovery of green beryl (emerald) near nature of the previously discussed Lit- Jones 2009). the Mountain River in 2007 (Fig. 15; tle Nahanni Pegmatite Group (Ercit et Tertiary coal on the eastern Mercier et al. 2008; Hewton et al. al. 2003; Barnes et al. 2007), consistent edge of the Mackenzie Mountains and 2011a, b; Hewton 2012) has opened up with the composition of the metalumi- adjacent to the Mackenzie River (Fig. the northern Mackenzie Mountains to nous O’Grady pluton (i.e., hornblende- 15) is the most economically significant the possibility of finding more emer- bearing, A-type pluton; Gordey and and is being examined for potential alds. The beryl is hosted in extensional Anderson 1993; Ercit et al. 2003). gasification. An historical resource esti- quartz–carbonate veins that cut Neo- mate of 1.544 billion in-place tonnes proterozoic sandstone, and yield a Re– of high-moisture, low-ash, 6500–8000 Os pyrite crystallization age of ca. 345 Btu/lb lignitic coal is reported, some Ma (Hewton 2012). Unlike the green GEOSCIENCE CANADA Volume 40 2013 61

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Y# Y# Y# Y# LR Y# Y#Y# Y# $T nm Y# $T Y#Y#61°N Y#Y# $T$T Y# Y# Y#Y#Y# #Y Geology Y#Y#Y#YY# NWT Mesozoic Foreland Basin YT Upper Paleozoic Siliciclastic/Carbonate Shelf Mineralization % Other $TnmY# Mountain River Beryl $T *# Coal nm Community 0 20406080100 G! Placer Canol Heritage Trail Kilometres

Figure 15. Distribution of known coal occurrences and associated strata, placer gold, and a new green beryl discovery (Mercier et al. 2008; Hewton 2012; Hewton et al. 2011b) in the Mackenzie and eastern Selwyn Mountains. 62 beryl at Lened (Fig. 13) and Regal Ridge (Groat et al. 2002; Marshall et al. 2004) the Mountain River beryl cannot be linked to a Cretaceous pluton; the nearest pluton is about 85 km to the southwest and it appears unlikely that one exists in the subsurface (Figs. 13 and 15; Mercier et al. 2008; Hewton et al. 2011a, b; Hewton 2012). This beryl more closely resembles Columbian or schist-type (Hewton et al. 2011a, b; Hewton 2012), rather than the predominantly igneous-related emeralds at Lened and Regal Ridge (Groat et al. 2002; Marshall et al. 2004).

CONCLUSIONS Many recent papers and publications have focused on the metallogenic evolution of distinct geological provinces, commodity-specific mineral deposit types, or mineral deposits related to particular geological events. The metallogenic evolution of the MSM area of the Cordilleran orogen has been, as a whole, overlooked. We have used the Northern Minerals database (NORMIN; www.nwtgeoscience.ca), which hosts all publicly reported commodity occurrences in the Northwest Territories, to identify mineral prospects and deposits that were then evaluated as part of targeted field investigations (e.g., Dewing et al. 2006; Rasmussen et al. 2007; Mercier et al. 2008; Leslie 2009; Wallace 2009; Fer- Figure 16. nandes 2011; Hewton et al. 2011b) and Summary diagram for the Mackenzie and eastern Selwyn Mountains regional bedrock investigations and metallogenic evolution in the context of western North America’s tectonic history. See text for discussion. mapping (e.g., Wright et al. 2007; Mar- tel et al. 2011). Classification of the known mineral commodities in the <750 Ma glacial marine-related Rapitan structurally-controlled carbonate-host- database by mineral deposit types has Group unconformably overlies the ed Zn–Pb (+ other base-metals; Fig. established the predominance of five Coates Lake Group and in the north- 16), preserved as a diverse collection of types and the limited presence of west hosts a massive stratiform iron mineral deposits and prospects. The other, less economically significant deposit in the form of hematite-jasper, mineralization styles and Pb isotopic commodities (Fig. 16). Each type nodular iron formation with lesser data indicate three to four carbonate- formed as a result of distinct geologic banded iron formation, interpreted to hosted deposit types. The timing of events. The combination of temporal, have been deposited during continued carbonate-hosted Zn–Pb deposits is geographic, stratigraphic, and tectonic rifting and Neoproterozoic glaciation only broadly constrained and any controls delineates districts and out- (Fig. 16). During the Paleozoic evolu- regional correlations should be consid- lines the metallogenic evolution of the tion of the western margin of North ered provisional. Finally, during the region (Fig. 16). America, a number of Zn–Pb SEDEX Cretaceous, in a distal, post-collision The oldest recognized deposit deposits formed during shale deposi- environment, melting of the mantle type is the rift-related, Kupferschiefer- tion in the Selwyn Basin; this includes and lower crust resulted in the forma- type Cu (±Ag) hosted by the <780 Ma the giant Howard’s Pass Zn district, tion of the Tombstone–Tungsten Suite Coates Lake Group (Fig. 16). Similari- which may be the world’s largest unde- of granitoid plutons (Fig. 16). Associ- ties with the African copper belt allow veloped zinc deposit. Also during the ated with the Tungsten Suite plutons in the speculation that there may be yet- Paleozoic, and possibly extending into the MSM area are intrusion-related unrecognized, large-tonnage deposits the Cenozoic and Mesozoic, the tungsten skarn deposits, of which the to be found in the MSM area. The Mackenzie Platform was the locus of Mactung and Cantung deposits are the GEOSCIENCE CANADA Volume 40 2013 63 largest tungsten deposits in North structure, Mackenzie Arc: Geological nomic Geologists, v. 105, p. 467–508, America. Some of the Cretaceous plu- Survey of Canada, Paper 74-1B, p. http://dx.doi.org/10.2113/gsecon- tons also have semi-precious and pre- 259–264. geo.105.3.467. cious gemstones, along with pegmatite- Aitken, J.D., Cook, D.G., and Yorath, C.J., Bowman, J.R., Covert, J.J., Clark, A.H., and hosted rare-elements. Other deposits 1982, Upper Ramparts River (106G) Mathieson, G.A., 1985, The CanTung and Sans Sault Rapids (106H) map E Zone scheelite skarn orebody, include Carboniferous and Cretaceous– Areas, District of Mackenzie: Geologi- Tungsten, Northwest Territories; oxy- Tertiary coal and minor modern placer cal Survey of Canada, Memoir 388, 48 gen, hydrogen, and carbon isotope gold occurrences (Fig. 16). The metal- p. studies: Economic Geology and The logeny of the Mackenzie and eastern Ansdell, K.M., Nesbitt, B.E., and Bulletin of the Society of Economic Selwyn Mountains has evolved over Longstaffe, F.J., 1989, A fluid inclu- Geologists, v. 80, p. 1872–1895, 700 million years, through a panoply of sion and stable- isotope study of the http://dx.doi.org/10.2113/gsecon- tectonic regimes, resulting in a diverse Tom Ba-Pb-Zn deposit, Yukon Terri- geo.80.7.1872. array of mineral deposits (Fig. 16), tory, Canada: Economic Geology and Brown, A., 2005, Refinements for footwall many of which may contain significant The Bulletin of the Society of Eco- red-bed diagenesis in the sediment- current and future natural resources. nomic Geologists, v. 84, p. 841–856, hosted stratiform copper deposits http://dx.doi.org/10.2113/gsecon- model: Economic Geology and The geo.84.4.841. Bulletin of the Society of Economic ACKNOWLEDGEMENTS Azmy, K., Kendall, B., Creaser, R.A., Hea- Geologist, v. 100, p. 765–771, Our ability to visit many of the man, L., and de Oliveira, T.F., 2008, http://dx.doi.org/10.2113/gsecon- deposits and prospects in the Macken- Global correlation of the Vazante geo.100.4.765. zie and eastern Selwyn Mountains was Group, São Francisco Basin, Brazil: Brown, P.E., Bowman, J.R., and Kelly, facilitated by the Sekwi Mountain Map- Re–Os and U–Pb radiometric age W.C., 1985, Petrologic and stable iso- ping project (NTGO–GSC), Peel constraints: Precambrian Research, v. tope constraints on the source and Plateau and Plain project (NTGO– 164, p. 160–172, http://dx.doi.org/ evolution of skarn-forming fluids at GSC–YGS), and the Nahanni MERA 10.1016/j.precamres.2008.05.001. Pine Creek, California: Economic project (GSC–Parks Canada). Discus- Bailes, R. J., Smee, B. W., Blackadar, D. W., Geology and The Bulletin of the Soci- sions with colleagues on these various and Gardner, H. D., 1986, Geology of ety of Economic Geologists, v. 80, p. the Jason lead-zinc-silver deposits, 72–95, http://dx.doi.org/10.2113/ operations, along with C. Jefferson and Macmillan Pass, eastern Yukon, in gsecongeo.80.1.72. T. Hadlari have greatly enhanced our Morin, J.A., ed., Mineral Deposits of Burchfiel, B.C., Cowan, D.S., and Davis, knowledge of the area. We are grateful Northern Cordillera Symposium: G.A., 1992, Tectonic overview of the to Canadian Zinc, Chevron Canada, Canadian Institute of Mining and Cordilleran orogen in the western North American Tungsten, Pacifica Metallurgy, Special Volume 37, p. United States, in Burchfiel, B.C., Resources (now Selwyn Chihong Min- 87–99. Limpan, P.W., and Zoback, M.L., eds., ing Ltd.), and Phelps Dodge (now Baldwin, G.J., Turner, E.C., and Kamber, The Cordilleran Orogen: Contermi- Freeport-McMoran) for access to their B.S., 2012, A new depositional model nous U.S.: Geological Society of properties and we are indebted to for glaciogenic Neoproterozoic iron America, The Geology of North Eagle Plains Resources, particularly R.J. formation: insights from the America, v. G-3, p. 407–479. chemostratigraphy and basin configu- Cameron, A.R., Goodarzi, F., Potter, J., Sharp working on their behalf, for col- ration of the Rapitan iron formation: 1994, Coal and oil shale of Early Car- laboration, support, and enthusiasm Canadian Journal of Earth Sciences, v. boniferous age in northern Canada; regarding the region. Comments on a 49, p. 455–476, http://dx.doi.org/ significance for paleoenvironmental preliminary version of this manuscript 10.1139/e11-066. and paleoclimatic interpretations: by Dan Kontak, Scott Cairns, and Barnes, E.M., Groat, L.A., and Falck, H., Palaeogeography, Palaeoclimatology, David Watson helped improve aspects 2007, A review of the late Cretaceous Palaeoecology, v. 106, p.135–155, of this paper. Reviews by Charlie Jef- Little Nahanni Pegmatite Group and http://dx.doi.org/10.1016/0031- ferson and Maurice Colpron helped associated rare-element mineralization 0182(94)90007-8. further clarify this contribution and we in the Selwyn Basin area, Northwest Carrière, J.J., and Sangster, D.F., 1999, A are grateful to Geoscience Canada Edi- Territories, in Wright, D.F., Lemkow, multidisciplinary study of carbonate- tor Brendan Murphy and Editorial D., and Harris, J., eds., Mineral and hosted zinc-lead mineralization in the Energy Resource Potential of the Pro- Mackenzie Platform (a.k.a. Blackwater Manager Cindy Murphy for their assis- posed Expansion to the Nahanni and Lac de Bois platforms), Yukon tance. This is NWT Geoscience Office National Park Reserve, North and Northwest Territories, Canada: contribution #0046. Cordillera, Northwest Territories: Geological Survey of Canada, Open Geological Survey of Canada, Open File 3700, 146 p., http://dx.doi.org/ REFERENCES File 5344, p.191–202. 10.4095/210821. Aitken, J.D., 1977, Redstone River Forma- Bekker, A., Slack, J.F., Planavsky, N., Cecile, M.P., 2000, Geology of the north- tion (Upper Proterozoic) in Mount Krapez, B., Hofmann, A., Konhauser, eastern Niddery Lake map area, east- Eduni and Bonnet Plume Lake map - K.O., and Rouxel, O.J., 2010, Iron central Yukon and adjacent Northwest Areas, District of Mackenzie: Geologi- Formation: The sedimentary product Territories: Geological Survey of cal Survey of Canada, Paper 77-01A, of a complex interplay among mantle, Canada, Bulletin 553, 122 p. p. 137–138. tectonic, oceanic, and biospheric Cecile, M.P., Morrow, D.W., and Williams, Aitken, J.D., and Cook, D.G., 1974, Effect processes: Economic Geology and G.K., 1997, Early Paleozoic (Cambrian of antecedent faults on “Laramide” The Bulletin of the Society of Eco- to Early Devonian) tectonic frame- 64

work, Canadian Cordillera: Bulletin of ries: Geological Survey of Canada, http://dx.doi.org/10.2113/gsecon- Canadian Petroleum Geology, v. 45, p. Open File 5344, 14 p. geo.77.4.845. 54–74. Dawson, K.M., 1996, Skarn deposits, in Dickinson, W.R., 2006, Geotectonic evolu- Černý, P., Blevin, P.L., Cuney, M., and Lon- Eckstrand, O.R., Sinclair, W.D., and tion of the Great Basin: Geosphere, v. don, D., 2005, Granite-related ore Thorpe, R.I. eds., Geological Survey of 2, p. 353–368, http://dx.doi.org/ deposits: Society of Economic Geolo- Canada, Geology of Canada 8, p. 10.1130/GES00054.1. gists, Economic Geology 100th 447–502. Dixon, J., 1999, Mesozoic-Cenozoic stratig- Anniversary Volume, p. 337–370. Dawson, K.M., and Dick, L.A., 1978, raphy of the northern Interior Plains Chartrand, F.M., and Brown, A.C., 1985, Regional metallogeny of the northern and Plateau, Northwest Territories: The diagenetic origin of stratiform Cordillera: tungsten and base metal- Geological Survey of Canada, Bulletin copper mineralization, Coates Lake, bearing skarns in southeastern Yukon 536, 56 p. Redstone copper belt, N.W.T., Canada: and southwestern Mackenzie: Geolog- Dudás, F.Ö., and Lustwerk, R.L., 1997, Economic Geology and The Bulletin ical Survey of Canada, Paper 78-1A, p. Geochemistry of the Little Dal of the Society of Economic Geolo- 287–292. basalts: continental tholeiites from the gists, v. 80, p. 325–343, Dawson, K.M., Panteleyev, A., Sutherland Mackenzie Mountains, Northwest Ter- http://dx.doi.org/10.2113/gsecon- Brown, A., and Woodsworth, G.J., ritories, Canada: Canadian Journal of geo.80.2.325. 1991, Regional metallogeny, Chapter Earth Sciences, v. 34, p. 50–58, Chartrand, F.M., Brown, A.C., and 19, in Gabrielse, H., and Yorath, C.J., http://dx.doi.org/10.1139/e17-004. Kirkham, R.V., 1989, Diagenesis, sul- eds., Geology of the Cordilleran Oro- Eisbacher, G.H., 1978, Two major Protero- phides, and metal zoning in the Red- gen in Canada: Geological Survey of zoic unconformities, Mackenzie stone copper deposit, Northwest Ter- Canada, Geology of Canada No. 4, p. Mountains: Geological Survey of ritories, in Boyle, R.W., Brown, A.C., 707–768. Canada, Paper 78-1A, p. 53–58. Jefferson, C.W., Jowett, E.C., and Day, S., Falck, H., Friske, P., Pronk, A., Eisbacher, G.H., 1981, Sedimentary tecton- Kirkham, R.V., eds., Sediment-Hosted McCurdy, M., McNeil, R., Adcock, S., ics and glacial record in the Winder- Stratiform Copper Deposits: Geologi- Grenier, A., 2009, Regional stream mere Supergroup, Mackenzie Moun- cal Association of Canada, Special sediment and water geochemical data, tains, northwestern Canada: Geologi- Paper 36, p. 189–206. Mount Eduni area, northern Macken- cal Survey of Canada, Paper 80-27, 40 Clout, J.M.F., and Simonson, B.M., 2005, zie Mountains NT (NTS 106A and p. Precambrian iron formations and part of 106B): Northwest Territories Ercit, T.S., Groat, L.A., and Gault, R.A., iron-formation-hosted iron ore Geoscience Office, NWT Open 2003, Granitic pegmatites of the deposits: Society of Economic Geolo- Report 2009-004, digital files. Avail- O’Grady batholith, N.W.T., Canada: A gists, Economic Geology 100th able from http://gateway.nwtgeo- case study of the evolution of the Anniversary Volume, p. 643–679. science.ca. elbaite subtype of rare-element Colpron, M., and Jefferson, C.W., 1998, DeCelles, P.G., 2004, Late Jurassic to granitic pegmatite: The Canadian Min- Geology of the Mount Kraft area, Eocene evolution of the Cordilleran eralogist, v. 41, p. 117–137, Mackenzie Mountains, Northwest Ter- thrust belt and foreland basin system, http://dx.doi.org/10.2113/gscan- ritories (NTS 95L/15): Northwest western U.S.A.: American Journal of min.41.1.117. Territories Geoscience Office, EGS Science, v. 304, p. 105–168, Evans, D.A.D., 2009, The palaeomagneti- 1998-02, 1 map, 1:50,000 scale. Avail- http://dx.doi.org/10.2475/ajs.304.2.1 cally viable, long-lived and all-inclusive able from http://gateway.nwtgeo- 05. Rodinia supercontinent reconstruc- science.ca. Delaney, G.D., Jefferson, C.W., Yeo, G.M., tion, in Murphy, J.B., Keppie, J.D., and Colpron, M., Logan, J.M., and Mortensen, McLennan, S.M., Bell, R.T. and Hynes, A.J., eds., Ancient Orogens and J.K., 2002, U-Pb zircon age constraint Aitken, J.D., 1982, Some Proterozoic Modern analogues: Geological Society, for late Neoproterozoic rifting and ini- sediment-hosted metal occurrences of London, Special Publication, v. 327, p. tiation of the lower Paleozoic passive the northeastern Canadian Cordillera, 371–404. margin of western Laurentia: Canadi- in Reid, R.R., and Williams, G.A., eds., Eyles, N., and Januszczak, N., 2004, “Zip- an Journal of Earth Sciences, v. 39, p. Society of Economic Geologists per-rift”: a tectonic model for Neo- 133–143, Couer d’Alene Field Conference 1977, proterozoic glaciations during the http://dx.doi.org/10.1139/e01-069. Idaho Bureau of Mines and Geology, breakup of Rodinia after 750 Ma: Colpron, M., Nelson, J.L., and Murphy, Bulletin 24, p. 97–116. Earth-Science Reviews, v. 65, p. 1–73, D.C., 2007, Northern Cordilleran ter- Dewing, K., Sharp, R.J., Ootes, L., Turner, http://dx.doi.org/10.1016/S0012- ranes and their interactions through E.C., and Gleeson, S., 2006, Geologic 8252(03)00080-1. time: GSA Today, v. 17, 7 p. assessment of known Zn-Pb show- Fanning, C.M., and Link, P.K., 2004, U-Pb Coney, P.J., Jones, D.L., and Monger, ings, Mackenzie Mountains, North- SHRIMP ages of Neoproterozoic J.W.H., 1980, Cordilleran suspect ter- west Territories: Geological Survey of (Sturtian) glaciogenic Pocatello For- ranes: Nature, v. 288, p. 329–333, Canada, Current Research 2006-A4, mation, southeastern Idaho: Geology, http://dx.doi.org/10.1038/288329a0. 12 p., http://dx.doi.org/10.4095/ v. 32, p. 881–884, http://dx.doi.org/ Cousens, B.L., 2007, Radiogenic isotope 222108. 10.1130/G20609.1. studies of Pb-Zn mineralization in the Dick, L.A., and Hodgson, C.J., 1982, The Fernandes, N.A., 2011, Geology and geo- Howard’s Pass area, Selwyn Basin, in MacTung W-Cu (Zn) contact metaso- chemistry of late Devonian-Mississip- Wright, D.F., Lemkow, D., and Harris, matic and related deposits of the pian sediment-hosted barite sequences J., eds., Mineral and Energy Resource northeastern Canadian Cordillera: of the Selwyn Basin, NWT and Potential of the Proposed Expansion Economic Geology and The Bulletin Yukon, Canada: Unpublished M.Sc. to the Nahanni National Park Reserve, of the Society of Economic Geolo- thesis, University of Alberta, Edmon- North Cordillera, Northwest Territo- gists, v. 77, p. 845–867, ton, AB, 98 p. GEOSCIENCE CANADA Volume 40 2013 65

Fraser, S.C., 1996, Geology and geochem- genesis of carbonate-hosted Zn-Pb, R.A., Mattey, D.P., Schwarz, D., Malus- istry of the Prairie Creek Zn, Pb, Ag shale-hosted Ba-Zn-Pb, and silver-rich ki, H., Wise, M.A., Wengzynowski, W., deposits, southern Mackenzie Moun- deposits in the northern Canadian and Eaton, D.W., 2002, Mineralogical tains, N.W.T.: Unpublished M.Sc. the- Cordillera: Economic Geology and and geochemical study of the Regal sis, University of Alberta, Edmonton, The Bulletin of the Society of Eco- Ridge emerald showing, southeastern Alberta, 146 p. nomic Geologists v. 77, p. 82–94, Yukon: The Canadian Mineralogist, v. Gabrielse, H., and Yorath, C.J., 1991, Intro- http://dx.doi.org/10.2113/gsecon- 40, p. 1313–1338, http://dx.doi.org/ duction, Chapter 1, in Gabrielse, H., geo.77.1.82. 10.2113/gscanmin.40.5.1313. and Yorath, C.J., eds., Geology of the Goodfellow, W.D., 2007, Base metal metal- Groat, L.A., Mulja, T., Mauthner, M.H.F., Cordilleran Orogen in Canada: Geo- logeny of the Selwyn Basin, in Good- Ercit, T.S., Raudsepp, M., Gault, R.A., logical Survey of Canada, Geology of fellow, W.D., ed., Mineral Deposits of and Rollo, H.A., 2003, Geology and Canada Series No. 4, p. 3–11, Canada: A Synthesis of Major Deposit mineralogy of the Little Nahanni rare- http://dx.doi.org/10.4095/134069. Types, District Metallogeny, the Evo- element granitic pegmatites, North- Gabrielse, H., Monger, J.W.H., Wheeler, lution of Geological Provinces, and west Territories: The Canadian Miner- J.O., and Yorath, C.J., 1991, Part A, Exploration Methods: Geological alogist, v. 41, p. 139–160, morphogeological belts, tectonic Association of Canada, Mineral http://dx.doi.org/10.2113/gscan- assemblages and terranes, Chapter 2, Deposits Division, Special Publication min.41.1.139. in Gabrielse, H., and Yorath, C.J., eds., No. 5, p. 553–581. Groat, L.A., Guiliani, G., Marshall, D.D., Geology of the Cordilleran Orogen in Goodfellow, W.D., and Lydon, J.W., 2007, and Turner, D., 2007, Emerald, in Canada: Geological Survey of Canada, Sedimentary Exhalative (SEDEX) Groat, L.A. ed., The Geology of Gem Geology of Canada No. 4, p. 15–28, deposits, in Goodfellow, W.D., ed., Deposits: Mineralogical Association of http://dx.doi.org/10.4095/134069. Mineral Deposits of Canada: A Syn- Canada, Short Course Series Volume Gerstner, M.R., Bowman, J.R., and Pasteris, thesis of Major Deposit Types, Dis- 37, p. 79–110. J.D., 1989, Skarn formation at the trict Metallogeny, the Evolution of Groff, J.A., Heizler, M.T., McIntosh, W.C., MacMillan Pass tungsten deposit Geological Provinces, and Exploration and Norman, D.I., 1997, 40Ar/39Ar dat- (MacTung), Yukon and Northwest Methods: Geological Association of ing and mineral paragenesis for carlin- Territories; I, P-T-X-V characteriza- Canada, Mineral Deposits Division, type gold deposits along the Getchell tion of the methane-bearing, skarn- Special Publication No. 5, p. 163–184. Trend, Nevada: Evidence for Creta- forming fluids: The Canadian Mineral- Goodfellow, W.D., and Rhodes, D., 1991, ceous and Tertiary gold mineraliza- ogist, v. 27, p. 545–563. Geology, geochemistry and origin of tion: Economic Geology and The Bul- Gleeson, S., 2006, A microthermometric the TOM stratiform Zn-Pb-Ag letin of the Society of Economic study of fluid inclusions in sulfides deposits, in Abbot, J.G. and Turner, Geologists, v. 92, p. 601–622, and carbonates from Gayna River and R.J., eds., Mineral Deposits of the http://dx.doi.org/10.2113/gsecon- the Bear-Twit base metal prospects, Northern Canadian Cordillera, Yukon geo.92.5.601. Mackenzie Mountains, NWT: North- - Northeastern British Columbia, Gross, G.A., 1970, Iron ore deposits of west Territories Geoscience Office, (Field Trip 14): Geological Survey of Canada and the West Indies: Survey of NWT Open Report 2006-005, 9 p. Canada, Open File 2169, p. 177–242. World Iron Ore Resources, United Available from www.nwtgeoscience.ca. Goodfellow, W.D., Cecile, M.P., Leybourne, Nations, New York, p.237–269. Gleeson, S.A. Sharp, R.J., Dewing, K., M.I., 1995, Geochemistry, petrogene- Hadlari, T., Davis, W.J., Dewing, K., Hea- Krstic, D., Turner, E.L., and Ootes, L., sis, and tectonic setting of lower Pale- man, L.M., Lemieux, Y., Ootes, L., 2007, A regional S and Pb isotope ozoic alkalic and potassic volcanic Pratt, B.R., and Pyle, L.J., 2012, Two study of carbonate hosted Zn-Pb rocks, Northern Canadian Cordilleran detrital zircon signatures for the Cam- mineralization, Mackenzie Mountains, Miogeocline: Canadian Journal of brian passive margin of northern Lau- NT, Canada (abstract): Proceedings of Earth Sciences v. 32, p. 1236–1254, rentia highlighted by new U-Pb results the 9th SGA conference, Dublin, Ire- http://dx.doi.org/10.1139/e95-101. from northern Canada: Geological land, p. 315–319. Gordey, S.P., and Anderson, R.G., 1993, Society of America Bulletin, v. 124, p. Godwin, C.I., and Price, B.J., 1986, Geolo- Evolution of the northern Cordilleran 1155–1168, , gy of the Mountain diatreme kimber- miogeocline, Nahanni map area http://dx.doi.org/10.1130/B30530.1. lite, north-central Mackenzie Moun- (105I), Yukon and Northwest Territo- Hannigan, P., 2007, Metallogeny of the tains, District of Mackenzie, North- ries: Geological Survey of Canada, Pine Point Mississippi Valley-type west Territories, in Morin, J.A., ed., Memoir 428, 214 p. zinc-lead district, southern Northwest Mineral Deposits of Northern Gordey, S.P., Geldsetzer, H.H.J.., Morrow, Territories, in Goodfellow, W.D., ed., Cordillera Symposium; Canadian Insti- D.W., Bamber, E.W., Henderson, C.M., Mineral Deposits of Canada: A Syn- tute of Mining and Metallurgy, Special Richards, B.C., McGugan, A., Gibson, thesis of Major Deposit Types, Dis- Volume 37, p. 87–99. D.W., and Poulton, T.P., 1991, Part A, trict Metallogeny, the Evolution of Godwin, C.I., and Sinclair, A.J., 1982, Aver- Ancestral North America, in Upper Geological Provinces, and Exploration age lead isotope growth curves for Devonian to Middle Jurassic assem- Methods: Geological Association of shale-hosted zinc-lead deposits, Cana- blages, Chapter 8, in Gabrielse, H., Canada, Mineral Deposits Division, dian Cordillera: Economic Geology and Yorath, C.J., eds., Geology of the Special Publication No. 5, p. 609–632. and The Bulletin of the Society of Cordilleran Orogen in Canada: Geo- Harlan, S.S., Heaman, L., LeCheminant, Economic Geologists, v. 77, p. logical Survey of Canada, Geology of A.N., and Premo, W.R., 2003, Gunbar- 675–690, http://dx.doi.org/10.2113/ Canada No. 4, p. 219–327. rel mafic magmatic event: A key 780 gsecongeo.77.3.675. Groat, L.A., Marshall, D.D., Giuliani, G., Ma time marker for Rodinia plate Godwin, C.I., Sinclair, A.J., and Ryan, B.D., Murphy, D.C., Piercey, S.J., Jambor, reconstructions: Geology, v. 31, p. 1982, Lead isotope models for the J.L., Mortensen, J.K., Ercit, T.S., Gault, 1053–1056, http://dx.doi.org/ 66

10.1130/G19944.1. Hitzman, M., Kirkham, R., Broughton, D., zircon ages, and rift tectonics, Harland, W.B., 2007, Origin and assess- Thorson, J., and Selley, D., 2005, The Mackenzie Mountains, northwestern ment of snowball Earth hypotheses: sediment-hosted stratiform copper ore Canada: Canadian Journal of Earth Geological Magazine, v. 144, p. system: Society of Economic Geolo- Sciences, v. 26, p. 1784–1801, 633–642, http://dx.doi.org/10.1017/ gists, Economic Geology 100th http://dx.doi.org/10.1139/e89-151. S0016756807003391. Anniversary Volume, p. 609–642. Jefferson, C.W., and Reulle, C.W., 1986, Hart, C.J.R., 2007, Reduced intrusion-relat- Hoffman, P.F., 1991, Did the breakout of The late Proterozoic Redstone copper ed gold systems, in Goodfellow, W.D., Laurentia turn Gondwanaland inside- belt, Mackenzie Mountains, Northwest ed., Mineral Deposits of Canada: A out?: Science, v. 252, p. 1409–1412, Territories, in Morin, J.A., ed., Mineral Synthesis of Major Deposit Types, http://dx.doi.org/10.1126/sci- Deposits of the northern Cordillera: District Metallogeny, the Evolution of ence.252.5011.1409. Canadian Institute of Mining and Geological Provinces, and Exploration Hoffman, P.F., and Halverson, G.P., 2011, Metallurgy, Special Volume 37, p. Methods: Geological Association of Neoproterozoic glacial record in the 154–168. Canada, Mineral Deposits Division, Mackenzie Mountains, northern Cana- Johnson, S.P., De Waele, B., Evans, D., Special Publication No. 5, p. 95–112. dian Cordillera, in Arnaud, E., Halver- Banda, W., Tembo, F., Milton, J.A., and Hart, C.J.R., Goldfarb, R.J., Lewis, L.L., son, G.P., and Shields-Zhou, G., eds., Tani, K., 2007, Geochronology of the Mair, J.L., 2004a, The Northern The Geological Record of Neopro- Zambezi supracrustal sequence, south- Cordilleran Mid- Cretaceous Plutonic terozoic Glaciations: Geological Socie- ern Zambia: A record of Neoprotero- Province: Ilmenite/magnetite-series ty, London, Memoirs 36, p. 397–411. zoic divergent processes along the granitoids and intrusion-related miner- Hoffman, P.F., and Schrag, D.P., 2002, The southern margin of the Congo Cra- alization: Resource Geology, v. 54, p. snowball Earth hypothesis: Testing the ton: The Journal of Geology, v. 115, 253–280, http://dx.doi.org/10.1111/ limits of global change: Terra Nova, v. p. 355–374, http://dx.doi.org/ j.1751-3928.2004.tb00206.x. 14, p. 129–155, http://dx.doi.org/ 10.1086/512757. Hart, C.J.R., Mair, J.L., Goldfarb, R.J., and 10.1046/j.1365-3121.2002.00408.x. Kendall, B., Creaser, R.A., and Selby, D., Groves, D.I., 2004b, Source and redox Hoffman, P.F., Macdonald, F.A., and 2006, Re-Os geochronology of post- controls on metallogenic variations in Halverson, G.P., 2011, Chemical sedi- glacial black shales in Australia: Con- intrusion-related ore systems, Tomb- ments associated with Neoproterozoic straints on the timing of “Sturtian” stone-Tungsten Belt, Yukon Territory, glaciation: iron formation, cap carbon- glaciation: Geology, v. 34, p. 729–732, Canada: Geological Society of Ameri- ate, barite and phosphorite, in Arnaud, http://dx.doi.org/10.1130/G22775.1. ca, Special Publication 389, p. E., Halverson, G.P., and Shields-Zhou, Klein, C., 2005, Some Precambrian banded 339–356. G., eds., The Geological Record of iron-formations (BIFs) from around Heal, G.E.N., 1976, The Wrigley-Lou and Neoproterozoic Glaciations: Geologi- the world: Their age, geologic setting, Polaris-Truro lead-zinc deposits, cal Society, London, Memoirs 36, p. mineralogy, metamorphism, geochem- N.W.T.: Unpublished M.Sc. thesis, 67–80. istry, and origin: American Mineralo- University of Alberta, Edmonton, AB, Hutchinson, R.W., and Albers, J.P., 1992, gist, v. 90, p. 1473–1499, 172 p. Metallogenic evolution of the http://dx.doi.org/10.2138/am.2005.1 Hewton, R.S., 1982, Gayna River: a Pro- Cordilleran region of the western 871. terozoic Mississippi Valley-type zinc- United States, in Burchfiel, B.C., Klein, C., and Beukes, N.J., 1993, Sedimen- lead deposit, in Hutchinson, R.W., Limpan, P.W., and Zoback, M.L., eds., tology and geochemistry of the glacio- Spence, C.D., and Franklin, J.M., eds., The Cordilleran Orogen: Contermi- genic late Proterozoic Rapitan iron- Precambrian Sulphide Deposits, H.S. nous U.S.: Geological Society of formation in Canada: Economic Geol- Robinson Memorial Volume: Geologi- America, The Geology of North ogy and The Bulletin of the Society of cal Association of Canada, Special America, v. G-3, p. 629–652. Economic Geologist, v. 88, p. Paper 25, p. 667–700. Hyndman, R.D., Flück, P., Mazzotti, S., 542–565, http://dx.doi.org/10.2113/ Hewton, M., 2012, Investigation of the Lewis, T.J., Ristau, J., and Leonard, L., gsecongeo.88.3.542. Mountain River beryl (Emerald vari- 2005, Current tectonics of the north- Klein, C., and Ladeira, E.A., 2004, Geo- ety) Occurrence, Mackenzie Moun- ern Canadian Cordillera: Canadian chemistry and mineralogy of Neopro- tains, Northwest Territories: Unpub- Journal of Earth Sciences, v. 42, p. terozoic banded iron-formations and lished M.Sc. thesis, Simon Fraser Uni- 1117–1136, http://dx.doi.org/ some selected, siliceous manganese versity, Burnaby, BC, 154 p. 10.1139/e05-023. formations from the Urucum District, Hewton, M., Marshall, D., Ootes, L., Creas- Jefferson, C.W., 1983, The Upper Protero- Mato Grosso do Sul, Brazil: Econom- er, R., Loughrey, L., and Martel, E., zoic Redstone copper belt, Mackenzie ic Geology and The Bulletin of the 2011a, Constraints on emerald miner- Mountains, N.W.T.: Unpublished Society of Economic Geologist, v. 99, alization in the Mackenzie Mountains: Ph.D. Thesis, The University of West- p. 1233–1244, http://dx.doi.org/ Direct evidence for a major Palaeozoic ern Ontario, London, ON, 445 p. 10.2113/gsecongeo.99.6.1233. fluid-flow event (abstract): 39th Yel- Jefferson, C.W., and Colpron, M., 1998, Klemic, H., 1970, Iron ore deposits of the lowknife Geoscience Forum, Yel- Geology of the Coppercap Mountain United States of America, Puerto lowknife, NT, November, 2011. area, Mackenzie Mountains, North- Rico, Mexico and central America: Hewton, M., Marshall, D., Ootes, L., Mar- west Territories (NTS 95L/10): NWT Survey of World Iron Ore Resources, tel, E., 2011b, Geochemical con- Geology Division, Indian and North- United Nations, New York, p. straints on the origin of emeralds at ern Affairs Canada, EGS 1998-04, 1 411–477. Mountain River, Mackenzie Moun- map, 1:50,000 scale. Available from Lang, J., 2000, Chapter 2: Tombstone- tains, NT, Canada: Northwest Territo- http://gateway.nwtgeoscience.ca. Tungsten magmatic belt: Mineral ries Geoscience Office, NWT Open Jefferson, C.W., and Parrish, R.R., 1989, Deposit Research Unit Magmatic- Report 2011-005, 28 p. Late Proterozoic stratigraphy, U-Pb Hydrothermal Project, Special Publi- GEOSCIENCE CANADA Volume 40 2013 67

cation Number 2: Mineral Deposit Basin: Geological Survey of Canada, Territories, Canada: Insights from Research Unit, University of British Open File 5700, 27 p., fluid inclusions and stable isotopes, Columbia, Vancouver, BC, p. 7–49. http://dx.doi.org/10.4095/226070. with implications for northern Lang, J.R., Baker, T., Hart, C.J.R., and Lund, K., 2008. Geometry of the Neopro- cordilleran emerald: The Canadian Mortensen, J.K., 2000, An exploration terozoic and Paleozoic rift margin of Mineralogist, v. 42, p. 1523–1539, model for intrusion-related gold sys- western Laurentia: implications for http://dx.doi.org/10.2113/gscan- tems: Society of Economic Geology mineral deposit settings: Geosphere, v. min.42.5.1523. Newsletter, no. 40, p. 1–15. 4, p. 429–444, http://dx.doi.org/ Martel, E., Turner, E.C., and Fischer, B.J. Leach, D.L., Sangster, D.F., Kelley, K.D., 10.1130/GES00121.1. eds., 2011, Geology of the central Large, R.R., Garven, G., Allen, C.R., Lund, K., Aleinikoff, J.N., Evans, K.V., and Mackenzie Mountains of the northern Gutzmer, J., and Walters, S., 2005, Fanning, C.M., 2003, SHRIMP U-Pb Canadian Cordillera, Sekwi Mountain Sediment-hosted lead-zinc deposits: a geochronology of Neoproterozoic (105P), Mount Eduni (106A), and global perspective: Society of Eco- Windermere Supergroup, central northwestern Wrigley Lake (95M) nomic Geologists, Economic Geology Idaho: Implications for rifting of map-areas, Northwest Territories: 100th Anniversary Volume, p. 561–607. western Laurentia and synchroneity of Northwest Territories Geoscience Lemieux, Y., Hadlari, T., and Simonetti, A., Sturtian glacial deposits: Bulletin of Office, NWT Special Volume 1, 423 p. 2011, Detrital zircon geochronology the Geological Society of America, v. Mathieson , G.A., and Clark, A.H., 1984, and provenance of Devono-Mississip- 115, p. 349–372, http://dx.doi.org/ The Cantung E Zone scheelite skarn pian strata in the northern Canadian 10.1130/0016-7606(2003)115 orebody, Tungsten, Northwest Terri- Cordilleran miogeocline: Canadian <0349:SUPGON>2.0.CO;2. tories; a revised genetic model: Eco- Journal of Earth Sciences, v. 48, p. Macdonald, F.A., Schmitz, M.D., Crowley, nomic Geology and The Bulletin of 515–541, http://dx.doi.org/10.1139/ J.L., Roots, C.F., Jones, D.S., Maloof, the Society of Economic Geologists, E10-056. A.C., Strauss, J.V., Cohen, P.A., John- v. 79, p. 883–901, http://dx.doi.org/ Leslie, C.D, 2009, Detrital zircon ston, D.T., and Schrag, D.P., 2010, Cal- 10.2113/gsecongeo.79.5.883. geochronology and rift-related mag- ibrating the Cryogenian: Science, v. Mauthner, M.H.F., Mortensen, J.K., Groat, matism: central Mackenzie Mountains, 327, p. 1241–1243, http://dx.doi.org/ L.A., and Ercit, T.S., 1995, Northwest Territories: Unpublished 10.1126/science.1183325. Geochronology of the Little Nahanni M.Sc. thesis, University of British MacNaughton, R.B., Roots, C.F., and Mar- pegmatite group, Selwyn Mountains, Columbia, Vancouver, BC, 224 p. tel, E., 2008, Neoproterozoic-(?) Cam- southwestern Northwest Territories: Li, Z.X., Evans, D.A.D., and Zhang, S., brian lithostratigraphy, northeast Canadian Journal of Earth Sciences, v. 2004, A 90° spin on Rodinia: possible Sekwi Mountain map area, Mackenzie 32, p. 2090–2097, http://dx.doi.org/ causal links between the Neoprotero- Mountains, Northwest Territories: 10.1139/e95-162. zoic supercontinent, superplume, true New data from measured sections; McClay, K.R., and Bidwell, G.E., 1986, polar wander, and low-latitude glacia- Geological Survey of Canada, Current Geology of the Tom deposit, Macmil- tion: Earth and Planetary Science Let- Research 2008-16, 17 p., lan Pass, Yukon, in Morin, J.A., ed., ters, v. 220, p. 409–421, http://dx.doi.org/10.4095/225901. Mineral Deposits of Northern http://dx.doi.org/10.1016/S0012- Mair, J.L., Hart, C.J.R., and Stephens, J.R., Cordillera Symposium; Canadian Insti- 821X(04)00064-0. 2006a, Deformation history of the tute of Mining and Metallurgy, Special Li, Z.X., Bogdanova, S.V., Collins, A.S., northwestern Selwyn Basin, Yukon, Volume 37, p. 100-114. Davidson, A., De Waele, B., Ernst, Canada: Implications for orogen evo- Meinert, L.D., Dipple, G.M., and Nicoles- R.E., Fitzsimons, I.C.W., Fuck, R.A., lution and mid-Cretaceous magma- cu, S., 2005, World skarn deposits: Gladkochub, D.P., Jacobs, J., Karl- tism: Geological Society of America Society of Economic Geologists, Eco- strom, K.E., Lu, S., Natapov, L.M., Bulletin, v. 118, p. 304–323, nomic Geology 100th Anniversary Vol- Pease, V., Pisarevsky, S.A., Thrane, K., http://dx.doi.org/10.1130/B25763.1. ume, p. 299–336. Vernikovsky, V., 2008, Assembly, con- Mair, J.L., Goldfarb, R.J., Johnson, C.A., Mercier, M., Ootes, L., Lalonde, A, and figuration, and break-up history of Hart, C.J.R., and Marsh, E.E., 2006b, Martel, É., 2008, Geology and miner- Rodinia: A synthesis: Precambrian Geochemical constraints on the gene- alogy of the Mountain River beryl Research, v. 160, p. 179–210, sis of the Scheelite Dome intrusion- (variety emerald) showing, Mackenzie http://dx.doi.org/10.1016/j.precam- related gold deposit, Tombstone Gold Mountains, NWT, Canada: Northwest res.2007.04.021. Belt, Yukon, Canada: Economic Geol- Territories Geoscience Office, NWT Long, D.G.F., and Turner, E.C., 2012, For- ogy and The Bulletin of the Society of Open Report 2008-001, 1 poster. mal definition of the Neoproterozoic Economic Geologists, v. 101, p. Available from http://gateway.nwt- Mackenzie Mountains Supergroup 523–553, http://dx.doi.org/10.2113/ geoscience.ca. (Northwest Territories), and formal gsecongeo.101.3.523. Morris, G.A., and Nesbitt, B.E., 1998, stratigraphic nomenclature for terrige- Marshall, D., Falck, H., Mann, B., Kirkham, Geology and timing of paleohydroge- nous clastic units of the Katherine G., and Mortensen, J., 2003, Geother- ological events in the Mackenzie Group; Geological Survey of Canada, mometry and fluid inclusion studies of Mountains, Northwest Territories, Open File 7112, 40 p. the E-zone biotite skarn, Cantung Canada, in Parnell, J., ed., Dating and Long, D.G.F., Rainbird, R.H., Turner, E.C., Mine, Tungsten, NWT; Abstract Vol- Duration of Fluid Flow and Fluid- and MacNaughton, R.B., 2008, Early ume of Talks and Posters, Yellowknife Rock Interaction: Geological Society, Neoproterozoic strata (Sequence B) of Geoscience Forum, Yellowknife, NT, London, Special Publication 144, p. mainland northern Canada and Victo- November 2003, p. 60. 161–172. ria and Banks islands: a contribution Marshall, D.D., Groat, L.A., Falck, H., Giu- Morrow, D.W., 1991, The Silurian-Devon- to the Geological Atlas of Northern liani, G., and Neufeld, H., 2004, The ian sequence in the northern part of Canadian Mainland Sedimentary Lened emerald prospect, Northwest the Mackenzie Shelf, Northwest Terri- 68

tories: Geological Survey of Canada, F.R., 1986, Logtung: a porphyry W-Mo Canada: Canadian Journal of Earth Bulletin 413, 121 p. deposit in the southern Yukon, in Sciences, v. 34, p. 34–49, Morrow, D.W., and Cumming, G.L., 1982, Morin, J.A., ed., Mineral Deposits of http://dx.doi.org/10.1139/e17-003. Interpretation of lead isotope data the northern Cordillera: Canadian Park, J.K., Buchan, K.L., and Harlan, S.S., from zinc-lead mineralization in the Institute of Mining and Metallurgy, 1995, A proposed giant radiating dyke northern part of the western Canadi- Special Volume 37, p. 274–287. swarm fragmented by the separation an Cordillera: Canadian Journal of Norford, B.S., and Orchard, M.J., 1983, of Laurentia and Australia based on Earth Sciences, v. 19, p. 1070–1078, Early Silurian age of rocks hosting paleomagnetism of ca. 780 Ma mafic http://dx.doi.org/10.1139/e82-088. lead-zinc mineralization at Howards intrusions in western North America: Narbonne, G.M., and Aitken, J.D., 1995, Pass, Yukon Territory and District of Earth and Planetary Science Letters, v. Neoproterozoic of the Mackenzie Mackenzie; local biostratigraphy of 132, p. 129–139, http://dx.doi.org/ Mountains, northwestern Canada: Pre- Road River Formation and Earn 10.1016/0012-821X(95)00059-L. cambrian Research, v. 73, p. 101–121, Group: Geological Survey of Canada, Pigage, L. C., 2004, Bedrock geology com- http://dx.doi.org/10.1016/0301- Paper 83-18, 35 p. pilation of the Anvil District (parts of 9268(94)00073-Z. Ootes, L., and Martel, E., 2010, Assay NTS 105K/2, 3, 5, 6, 7 and 11), cen- Nelson, J., and Colpron, M., 2007, Tecton- results from the Sekwi Mountain map- tral Yukon: Yukon Geological Survey, ics and metallogeny of British Colum- ping project (2007 and 2008 field sea- Bulletin 15, 103 p. bia, Yukon, and Alaskan Cordillera, sons): Northwest Territories Geo- Potter, J., Richards, B.C., and Cameron, 1.8 Ga to the present, in Goodfellow, science Office, NWT Open Report A.R., 1993, The petrology and origin W.D., ed., Mineral Deposits of Canada: 2010-001, 13 p. of coals from the lower Carboniferous A Synthesis of Major Deposit Types, Ootes, L., Martel, E., and Roots, C.F., Mattson formation, southwestern Dis- District Metallogeny, the Evolution of 2007, Assay results from the Sekwi trict of Mackenzie, Canada: Interna- Geological Provinces, and Exploration Mapping Project (2006 field season): tional Journal of Coal Geology, v. 24, Methods: Geological Association of Northwest Territories Geoscience p. 113–140, http://dx.doi.org/ Canada, Mineral Deposits Division, Office, NWT Open Report 2007-006, 10.1016/0166-5162(93)90007-W. Special Publication No. 5, p. 755–791. 17 p. Pyle, L., and Jones, A.L. eds., 2009, Region- Nelson, J., Paradis, S., Christensen, J., and Paradis, S., 2007, Isotope geochemistry of al geoscience studies and petroleum Gabites, J., 2002, Canadian Cordilleran the Prairie Creek carbonate-hosted potential, Peel Plateau and Plain, Mississippi Valley-type deposits: A zinc-lead silver deposit, southern Northwest Territories and Yukon: case for Devonian-Mississippian back- Mackenzie Mountains, Northwest Ter- Project Volume: Northwest Territories arc hydrothermal origin: Economic ritories, in Wright, D.F., Lemkow, D., Geoscience Office, NWT Open File Geology and The Bulletin of the Soci- and Harris, J., eds., Mineral and Energy 2009-02, 549 p. ety of Economic Geologist, v. 97, p. Resource Potential of the Proposed Rainbird, R.H., Jefferson, C.W., and Young, 1013–1036, http://dx.doi.org/ Expansion to the Nahanni National G.M., 1996, The early Neoproterozoic 10.2113/gsecongeo.97.5.1013. Park Reserve, North Cordillera, sedimentary Succession B of north- Nelson, J., Colpron, M., Piercey, S.J., Dusel- Northwest Territories: Geological Sur- western Laurentia: Correlations and Bacon, C., Murphy, D.C., and Roots, vey of Canada, Open File 5344, p. paleogeographic significance: Geologi- C.F., 2006, Paleozoic tectonic and 131–176. cal Society of America Bulletin, v. 108, metallogenic evolution of pericratonic Paradis, S., Turner, W.A., Coniglio, M., Wil- p. 454–470, http://dx.doi.org/ terranes in Yukon, northern British son, N., and Nelson, J.L., 2006, Stable 10.1130/0016-7606(1996)108 Columbia and eastern Alaska, in Col- and radiogenic isotopic signatures of <0454:TENSSB>2.3.CO;2. pron, M., and Nelson, J., eds., Paleo- mineralized Devonian carbonate rocks Rasmussen, K.L., 2004, The aplitic dykes zoic Evolution and Metallogeny of of the northern Rocky Mountains and of the Cantung Mine; petrography, Pericratonic Terranes at the Ancient the Western Canada Sedimentary geochemistry, and implications for the Pacific Margin of North America, Basin, in Hannigan, P.K., ed., Potential mineralization process: Unpublished Canadian and Alaskan Cordilleran: for Carbonate-hosted Lead-Zinc Mis- B.Sc. thesis, University of Calgary, Geological Association of Canada, sissippi Valley-type Mineralization in Calgary, AB, 128 p. Special Paper 45, p. 323–360. Northern Alberta and Southern Rasmussen, K.L., Mortensen, J.K., and Newberry, R.J., 1982, Tungsten-bearing Northwest Territories: Geological Sur- Falck, H., 2006, Morphological and skarns of the Sierra Nevada. I. The vey of Canada, Bulletin 591, p. compositional analysis of placer gold Pine Creek mine, California: Econom- 75–103. in the South Nahanni River drainage, ic Geology and The Bulletin of the Paradis, S., Hannigan, P., and Dewing, K., Northwest Territories, in Emond, D.S., Society of Economic Geologists, v. 2007, Mississippi Valley-type lead-zinc Lewis, L.L., and Weston, H., eds., 77, p. 823–844, http://dx.doi.org/ deposits, in Goodfellow, W.D., ed., Yukon Exploration and Geology 10.2113/gsecongeo.77.4.823. Mineral Deposits of Canada: A Syn- 2006: Yukon Geological Survey, p. Noble, S.R., Spooner, E.T.C., and Harris, thesis of Major Deposit Types, Dis- 237–250. F.R., 1984, The Logtung large ton- trict Metallogeny, the Evolution of Rasmussen, K.L., Mortensen, J.K., Falck, nage, low grade W (scheelite)-Mo por- Geological Provinces, and Exploration H. and Ullrich, T.D., 2007, The poten- phyry deposit. south-central Yukon Methods: Geological Association of tial for intrusion-related mineralization Territory: Economic Geology and The Canada, Mineral Deposits Division, within the South Nahanni River Bulletin of the Society of Economic Special Publication No. 5, p. 185–203. MERA area, Selwyn and Mackenzie Geologists, v. 79, p. 848–868, Park, J.K., 1997, Paleomagnetic evidence Mountains, Northwest Territories, in http://dx.doi.org/10.2113/gsecon- for low-latitude glaciation during dep- Wright, D.F., Lemkow, D., and Harris, geo.79.5.848. osition of the Neoproterozoic Rapitan J., eds., Mineral and Energy Resource Noble, S.R., Spooner, E.T.C., and Harris, Group, Mackenzie Mountains, N.W.T., Potential of the Proposed Expansion GEOSCIENCE CANADA Volume 40 2013 69

to the Nahanni National Park Reserve, Selwyn Chihong Mining Limited, 2012, Ecosystem under consideration for North Cordillera, Northwest Territo- Table 1: NI 43-101 Global Mineral the expansion of the Nahanni Nation- ries: Geological Survey of Canada, Resource Growth from 2006 to 2012: al Park Reserve, Northwest Territo- Open File 5344, 90 p. Selwyn Resources Resource Inventory, ries: Geological Survey of Canada, Rasmussen, K.L., Mortensen, J.K., Arehart, Available from http://www.selwynre- Open File 5344, 557 p., G., 2010, Radiogenic and stable iso- sources.com/en/selwyn_resources.cf http://dx.doi.org/10.4095/224425. topic compositions of mid-Cretaceous m Yeo, G.M., 1981, The late Proterozoic Rap- intrusions in the Selwyn Basin, Yukon Stacey, J.S., and Kramers, J.D., 1975, itan glaciation in the northern and Northwest Territories: GeoCana- Approximation of terrestrial lead iso- Cordillera, in Campbell, F.H.A., ed., da Meeting 2010, Calgary, AB, May tope evolution by a two-stage model: Proterozoic Basins of Canada: Geo- 2010, 4 p. Earth and Planetary Science Letters, v. logical Survey of Canada, Paper 81-10, Rasmussen, K.L., Lentz, D.R., Falck, H., 26, p. 207–221, http://dx.doi.org/ p. 25–46. and Pattison, D.R.M., 2011, Felsic 10.1016/0012-821X(75)90088-6. Yeo, G.M., 1986, Iron-formation in the late magmatic phases and the role of late- Turner, E.C., and Long, D.G.F., 2008, Proterozoic Rapitan Group, Yukon stage aplitic dykes in the formation of Basin architecture and syndepositional and Northwest Territories, in Morin, the world-class Cantung Tungsten fault activity during deposition of the J.A., ed., Mineral Deposits of the skarn deposit, Northwest Territories, Neoproterozoic Mackenzie Mountains northern Cordillera: Canadian Insti- Canada: Ore Geology Reviews, v. 41, supergroup, Northwest Territories, tute of Mining and Metallurgy, Special p. 75–111, http://dx.doi.org/10.1016/ Canada: Canadian Journal of Earth Volume 37, p. 142–153. j.oregeorev.2011.06.011. Sciences, v. 45, p. 1159–1184, Young, G.M., 1992, Late Proterozoic Ricketts, B.D., 1984, A coal index for http://dx.doi.org/10.1139/E08-062. stratigraphy and the Canada-Australia Yukon and District of Mackenzie, Turner, E.C., and Long, D.G.F., 2012, For- connection: Geology, v. 20, p. Northwest Territories: Geological Sur- mal definition of the Neoproterozoic 215–218, http://dx.doi.org/10.1130/ vey of Canada, Open File 1115, 8 p. Mackenzie Mountains Supergroup 00917613(1992)020<0215:LPSATC>2 Ross, G.M., and Villeneuve, M.E., 1997, U- (NWT), and formal stratigraphic .3.CO;2. Pb geochronology of stranger stones nomenclature for its carbonate and Young, G.M., 2002, Stratigraphic and tec- in Neoproterozoic diamictites, Canadi- evaporite formations: Geological Sur- tonic settings of Proterozoic glacio- an Cordillera: Implications for prove- vey of Canada, Open File 7112, 57 p. genic rocks and banded iron-forma- nance and ages of deposition: Geo- Turner, R.J.W., 1991, JASON stratiform tions: relevance to the snowball Earth logical Survey of Canada, Current Zn-Pb-Ba deposit, Selwyn Basin, debate: Journal of South African Research 1997-F, p. 141–155. Canada (NTS 105-O-1): geological Earth Sciences, v. 35, p. 451–466. Ross, G.M., Patchett, P.J., Hamilton, M., setting, hydrothermal facies and gene- Yuvan, J., Shelton, K., and Falck, H., 2007, Heaman, L., DeCelles, P.G., Rosen- sis, in Abbot, J.G. and Turner, R.J., eds., Geochemical investigations of the berg, E., and Giovanni, M.K., 2005, Mineral Deposits of the Northern high-grade quartz-scheelite veins of Evolution of the Cordilleran orogen Canadian Cordillera, Yukon - North- the Cantung mine, Northwest Territo- (southwestern Alberta, Canada) eastern British Columbia, (Field Trip ries, in Wright, D.F., Lemkow, D., and inferred from detrital mineral 14): Geological Survey of Canada, Harris, J., eds., Mineral and Energy geochronology, geochemistry, and Nd Open File 2169, p. 137–176. Resource Potential of the Proposed isotopes in the foreland basin: Bulletin Tveten, M.A., 2007, Technical Report; Expansion to the Nahanni National of the Geological Society of America, Northwest Territories-Tulita coal Park Reserve, North Cordillera, v. 117, p. 747–763, prospect, prepared for West Hawk Northwest Territories: Geological Sur- http://dx.doi.org/10.1130/B25564.1. Development Corporation: Weir Inter- vey of Canada, Open File 5344, p. Sears, J.W., and Price, R.A., 2003, Tighten- national, Inc., 86 p. Available from 177–190, http://dx.doi.org/10.4095/ ing the Siberian connection to western www.westhawkdevelopment.com. 224425. Laurentia: Geological Society of Wallace, S.R.B., 2009, The genesis of the America Bulletin, v. 115, p. 943–953, Gayna River carbonate-hosted Zn-Pb Received September 2012 http://dx.doi.org/10.1130/B25229.1. deposit: Unpublished M.Sc. thesis, Accepted as revised December 2012 Selby, D., Creaser, R.A., Heaman, L.M., and University of Alberta, Edmonton, AB, Hart, C.J.R., 2003, Re–Os and U–Pb 124 p. geochronology of the Clear Creek, Wells, M.L., and Hoisch, T.D., 2008, The Dublin Gulch, and Mactung deposits, role of mantle delamination in wide- Tombstone Gold Belt, Yukon, Cana- spread Late Cretaceous extension and da: Absolute timing relationships magmatism in the Cordilleran orogen, between plutonism and mineralization: western United States: Geological Canadian Journal of Earth Sciences, v. Society of America Bulletin, v. 120, p. 40, p. 1839–1852, http://dx.doi.org/ 515–530, http://dx.doi.org/10.1130/ 10.1139/e03-077. B26006.1. Selley, D., Broughton, D., Scott, R., Hitz- Wheeler, J.O., Hoffman, P.F., Card, K.D., man, M., Bull, S., Large, R., Davidson, A. Sanford, B.V., Okulitch, McGoldrick, P., Selley Croaker, M., A.V., and Roest, W.R., 1996, Geologi- Pollington, N., and Barra, F., 2005, A cal map of Canada: Geological Survey new look at the Zambian Copperbelt: of Canada, “A” Series Map 1860A. Society of Economic Geologists, Eco- Wright, D.F., Lemkow, D., Harris, J.R., eds. nomic Geology 100th Anniversary Vol- 2007, Mineral and energy resource ume, p. 965–1000. assessment of the Greater Nahanni