©2008 Society of Economic Geologists, Inc. Economic Geology, v. 103, pp. 1057–1077

Geology of the Giant Sudbury Polymetallic Mining Camp, Ontario, Canada

D. E. AMES,† Geological Survey of Canada, 601 Booth St., Ottawa, ON K1A 0E8, Canada

A. DAVIDSON, 3259 Margaret Rd., Regina, SK S4V 1B2, Canada

AND N. WODICKA Geological Survey of Canada, 601 Booth St., Ottawa, ON K1A 0E8, Canada

Introduction Geologic Setting A NEW, 1:100,000 SCALE compilation bedrock geology map Sudbury structure provided with this issue presents a geologic synthesis of Canada’s most prolific mining camp, the world-class Sudbury The bolide that impacted the continental margin of Nuna, structure with total past production and current reserves of Earth’s first supercontinent, produced the ~200 km, 1850 Ma over 1.7 billion tonnes of Ni, Cu, Co, Pt, Pd, Au, Ag ore Sudbury impact crater. The Sudbury structure, a deformed (Lydon, 2007). The polymetallic ore is hosted within one of remnant of an impact basin, straddles the boundary between Earth’s largest preserved impact craters. The new map of the Neoarchean tonalitic Levack gneiss and Paleoproterozoic Ni-Cu-PGE Sudbury district (after Ames et al., 2005) is in- metavolcanic and metasedimentary Huronian Supergroup cluded in a pocket at the back of this issue (Map 1) and is strata, and related granitic rocks (Fig. 2). The most prominent linked to mineral deposit-commodity and geochronology data feature of the eroded remnant of the original, much more ex- in Tables 1 and 2 of this paper. tensive multi-ring impact basin (Spray et al., 2004) is the Sudbury Igneous Complex, which is interpreted as a melt Since 1891, six compilation maps of the geology of Sudbury × have been published (Bell, 1891; Collins, 1937; Cooke, 1946; sheet and includes the 60 30 km deformed outline of the Card, 1969; Dressler, 1984; Ames et al., 2005) (Fig. 1). Some Sudbury Igneous Complex and associated radial and concen- of the Ni-Cu-PGE mines have operated for over a century, tric offset dikes (Map 1, units 36–40) (Grieve et al., 1991; whereas new ore deposits, discovered as recently as 2004, are Lightfoot et al., 1997). The impact model for the Sudbury already in production or are in the process of being developed structure has been widely accepted since its inception over (i.e., advanced prospects). In the last 15 years, Sudbury has 40 years ago following the recognition of shatter cones been the training ground for ~60 postgraduate geoscience (Dietz, 1964). The shatter cones, which form a 10-km-wide students in North America (Fig. 1). From 1903 to 1990, only halo around the Sudbury Igneous Complex, generally point 23 graduate theses were completed on Sudbury-related top- 35 ics; eight of them in the 1970s, after the discovery of shatter IIrr cones (Dietz, 1964). IIrr distaldistal pproximalroximal Map 1 presents new information on (1) the impactites 30 (Stöffler and Grieve, 2007) of the Sudbury impact crater (units 34–46), which include the Sudbury Igneous Complex 25

and related radial and concentric offset dikes, the impact e theses

et al. crater infill breccia dikes, the impact crater infill of the On- 20

l

Card

Cooke

Ames aping Formation, pseudotachylite and other impact features Collins

Bel such as shatter cones, (2) the Neoarchean Levack gneiss com- Dressler 15 plex in the northern footwall, and (3) the Grenville Front area. The explicit interpretation of the origin of the igneous of graduat complex as a differentiated melt sheet in the Sudbury impact 10 structure, overlain by and assimilating its own fallback brec- 5 DDiscoveryiscovery o off cias (Grieve et al., 1991), is now widely accepted as a general Number DDiscoveryiscovery ofof IIrr a anomalynomaly framework. New data on these features, described in more sshatterconeshattercones

190 1910 1920 1930 1940 195 196 197 198 199 200 200 detail below, are integrated with a compilation of U-Pb 0 1890 * *

0 0 7 geochronology, mineral deposits, and occurrences (including 0 0 0 0 0 surface projections of mineralization and recent discoveries), Decade and previous bedrock mapping. This compilation map con- FIG. 1. Number of graduate theses of North American geoscientists tributes to our understanding of one of the world’s geologic trained on Sudbury geology per decade, showing the minor peak in training features of extraordinary economic and scientific importance. after the discovery of shatter cones and the recent “education boom,” with over 50 geoscience graduate theses completed since 1990. The dashed lines represent the regional geologic maps of the Sudbury area produced over the † Corresponding author: e-mail, [email protected] history of the Sudbury mining camp.

0361-0128/08/3764/1057-21 1057 1058 AMES ET AL.

TABLE 1. List of Mineral Deposits and Occurrences of the Sudbury Map Area (Map 1)

Location no. Name Commodity Source of data

NTS Sheet 041I05 1 Kordal no. 2 Ni, Cu, Co Ontario Mineral Deposit Inventory 2 Kordol main zone Ni, Cu, Co, Pd Ontario Mineral Deposit Inventory 3 Kordal no. 3 Ni, Cu, Co Ontario Mineral Deposit Inventory 4 Pond, Gaele Pond West Ni, Cu Ontario Mineral Deposit Inventory 5 Kordal no. 4 zone Ni, Cu, Co Ontario Mineral Deposit Inventory 6 Trill Offset Ni, Cu, PGE Wallbridge Inc 7 Lot 12, Con 4, Tamminen, T, Pond showing no. 2 Cu Ontario Mineral Deposit Inventory 8 Lot 11, Con 3 Cu Ontario Mineral Deposit Inventory 9 Agnew Lake mine U, Cu, Th Dressler, 1984 10 Ni, Cu Dressler, 1984 11 Lot 10, Con 2 Cu Ontario Mineral Deposit Inventory 12 Ministic Creek, Lot 10, Con 4, Alford Ni, Cu Ontario Mineral Deposit Inventory 13 Trillabelle Ni, Cu Dressler, 1984 14 U Dressler, 1984 15 Ryanor, Alanen And Maki Cu Ontario Mineral Deposit Inventory 16 Lot 8, Con 3 Ni, Cu Ontario Mineral Deposit Inventory 17 Sultana Ni, Cu Dressler, 1984 18 Robb Farm, Se 1/4, S1/2 Lot 7, Con 1 Ni, Cu Ontario Mineral Deposit Inventory 19 Garrison Harbour, Dwyer U. Cu Ontario Mineral Deposit Inventory

NTS Sheet 041I06 1 Alanen And Maki U, Cu, Th Ontario Mineral Deposit Inventory 2 Dwyer Au, Ag Ontario Mineral Deposit Inventory 3 Lot 6, Con 4 Cu Cu Ontario Mineral Deposit Inventory 4 Lot 5, Con 2 Cu Ontario Mineral Deposit Inventory 5 Lot 6, Con 3 Ni, Cu Ontario Mineral Deposit Inventory 6 Sudbury Lode Mines Cu, Au, Pb, Zn Ontario Mineral Deposit Inventory 7 Grimsell, Paramaque Ni, Cu Ontario Mineral Deposit Inventory 8 Lot 5, Con 3, Grimsell 2, Paramaque 2 Ni, Cu Ontario Mineral Deposit Inventory 9 Lot 4, Con 4 North Ni, Cu Ontario Mineral Deposit Inventory 10 Lot 4, Con 4 South Ni, Cu Ontario Mineral Deposit Inventory 11 Ni, S Dressler, 1984 12 Chicago mine Ni, Cu Dressler, 1984 13 Worthington Mines prospect Ni, Cu Ontario Mineral Deposit Inventory 14 Loughrim & Dwyer prospect Ni, Cu Ontario Mineral Deposit Inventory 15 Totten Ni, Cu, PGE Ames et al., 2003 16 Ni, S Dressler, 1984 17 Ni, Cu Dressler, 1984 18 Worthington mine Ni, Cu Dressler, 1984 19 Tamminen Ni, Cu Ontario Mineral Deposit Inventory 20 Ni, Cu Dressler, 1984 21 Ni, S Dressler, 1984 22 Ni, S Dressler, 1984 23 Boundary Ni, Cu Ontario Mineral Deposit Inventory 24 Howland pit Ni, Cu Card, 1968 25 AER Ni, Cu Ames et al., 2003 26 Ni, Cu Dressler, 1984 27 Pilspanen, V Ni Ontario Mineral Deposit Inventory 28 Kidd Copper Ni, Cu, PGE Dressler, 1984 29 Ni, S Dressler, 1984 30 Ni, Cu Dressler, 1984 31 Lot 11, Con 2 Cu Ontario Mineral Deposit Inventory 32 Ni, S Dressler, 1984 33 McIntyre mine/Gersdorffite Ni, Cu Dressler, 1984 34 Ni, S Dressler, 1984 35 Ni, Cu Dressler, 1984 36 Ni, Cu Dressler, 1984 37 Ni, Cu Dressler, 1984 38 Victoria mine Ni, Cu, PGE Ames et al., 2003 39 Ethel Lake Cu Ontario Mineral Deposit Inventory 40 Ni, Cu Dressler, 1984 41 Lots 6,7,8, Con 3, Denison Tp Cu Ontario Mineral Deposit Inventory 42 Vermilion mine Ni, Cu, PGE Dressler, 1984 43 Ni, Cu Dressler, 1984 44 Crean Hill mine Ni, Cu Dressler, 1984 45 Lots 3 and 4, Con 4 Cu Ontario Mineral Deposit Inventory 46 Lots 3 and 4, Con 5 Cu Ontario Mineral Deposit Inventory 47 Ni, Cu Dressler, 1984

0361-0128/98/000/000-00 $6.00 1058 GEOLOGY OF THE GIANT SUDBURY MINING CAMP, ONTARIO, CANADA 1059

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

48 Lockerby mine Ni, Cu, PGE Dressler, 1984 49 Ellen pit Ni, Cu Dressler, 1984 50 Ranger, Henry Au, Cu, Pb Ontario Mineral Deposit Inventory 51 Vermilion River Mo Ontario Mineral Deposit Inventory 52 McVittie-Graham Ni, Cu, PGE Dressler, 1984 53 Lot 12, Con 3, Graham Copper-Lot 12 Cu Ontario Mineral Deposit Inventory 54 Simpson Au, Ag, Cu, PGE Ontario Mineral Deposit Inventory 55 Lots 9,10,11, Con 4 Cu Ontario Mineral Deposit Inventory 56 Lot 9, Con 3 Cu Ontario Mineral Deposit Inventory 57 Lot 8, Con 4 Cu Ontario Mineral Deposit Inventory 58 Lot 7,8, Con 3 Ni, Cu Ontario Mineral Deposit Inventory 59 Lots 6,7,8, Con 3 Cu Ontario Mineral Deposit Inventory 60 Nemag Lake Cobalt Co Ontario Mineral Deposit Inventory 61 Russell Property, Lot 6 Con 3 Cu, Co Ontario Mineral Deposit Inventory 62 Lot 6, Con 3 Pb, As, Co, Cu Ontario Mineral Deposit Inventory 63 Lots 5,6 Con 3 Ni, Cu Ontario Mineral Deposit Inventory 64 Ni, Cu Dressler, 1984 65 Gertrude mine Ni, Cu Dressler, 1984 66 Century mine Ni, Co, Cu Ontario Mineral Deposit Inventory 67 Ni, Cu Dressler, 1984 68 Lots 1,2,3, Con 4 Cu Ontario Mineral Deposit Inventory 69 Lot 2, Con 4 Ni Ontario Mineral Deposit Inventory 70 Creighton mine Ni, Cu, PGE Dressler, 1984 71 Waters sulfide F Cu Ontario Mineral Deposit Inventory 72 Waters sulfide E Cu Ontario Mineral Deposit Inventory 73 Waters sulfide I Cu Ontario Mineral Deposit Inventory 74 Waters sulfide H Cu Ontario Mineral Deposit Inventory 75 Waters sulfide G Cu Ontario Mineral Deposit Inventory 76 North Star mine Ni, Cu Ames et al., 2003 77 Waters Tp Cu Ontario Mineral Deposit Inventory 78 J. Rauhala Ni, Cu Ontario Mineral Deposit Inventory 79 Kettyle,C.J. Au Ontario Mineral Deposit Inventory 80 Tam O’Shanter Ni, Cu Dressler, 1984 81 Campbell, P.C. Au, Ag, Pb Ontario Mineral Deposit Inventory 82 Babcock, J Ni, Cu Ontario Mineral Deposit Inventory 83 Mccormack, R. Au, Ag Ontario Mineral Deposit Inventory 84 Fielding property W Ontario Mineral Deposit Inventory 85 Copper Cliff South mine Ni, Cu Dressler, 1984 86 Copper Cliff no. 1 mine Ni, Cu Dressler, 1984 87 Evans mine Ni, Cu Dressler, 1984 88 Clarabelle pit Ni, Cu Dressler, 1984 89 Copper Cliff mine Ni, Cu Dressler, 1984 90 Copper Cliff North Ni, Cu, PGE Ames et al., 2003 91 Kelly Lake Ni, Cu, PGE Ames et al., 2003 92 Copper Cliff no. 2 mine Ni, Cu Dressler, 1984 93 Mckim L occurrence Ni, Cu Ontario Mineral Deposit Inventory 94 Mckim M occurrence Ni, Cu Ontario Mineral Deposit Inventory 95 Mckim J showing Ni, Cu Ontario Mineral Deposit Inventory 96 Meito-Laasko Cu, Ni, Ag Ontario Mineral Deposit Inventory 97 Ramsey Lake, Ennis Cu, Ni, Au Ontario Mineral Deposit Inventory

NTS Sheet 041I07 1 Mckim H showing Ni, Cu Ontario Mineral Deposit Inventory 2 Mckim I showing Ni Ontario Mineral Deposit Inventory 3 Kingsway showing Cu Ontario Mineral Deposit Inventory 4 Broder Ne Ni, Cu Ontario Mineral Deposit Inventory 5 Minnow Lake West pit Ni Ontario Mineral Deposit Inventory 6 Mccormick, Mccormicks mine (Misnomer) Ni, Cu Ontario Mineral Deposit Inventory 7 Arcadia South showing Ni, Cu Ontario Mineral Deposit Inventory 8 Arcadia, Amax Neelon, Arcadia Nickel Corp Ni, Cu Ontario Mineral Deposit Inventory 9 Wanapitei Complex Neelon Ni, Cu Ontario Mineral Deposit Inventory 10 Pershland South Ni, Cu Ontario Mineral Deposit Inventory 11 Ni, Cu Dressler, 1984 12 kyanite Dressler, 1984 13 kyanite Dressler, 1984

NTS Sheet 041I10 1 Mt Nickel mine Ni, Cu Ames et al., 2003 2 Stobie mine Ni, Cu, PGE Ames et al., 2003

0361-0128/98/000/000-00 $6.00 1059 1060 AMES ET AL.

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

3 Lindsley mine Ni, Cu, PGE Ames et al., 2003 4 Cu, Zn Gibbins et al., 2004 5 Blezard mine Ni, Cu Dressler, 1984 6 Papineau Au, Ag, Cu, Pb Ontario Mineral Deposit Inventory 7 Microwave showing Ni, Cu Ontario Mineral Deposit Inventory 8 Lasalle Cu, Ni, Ag, Au Ontario Mineral Deposit Inventory 9 Pyrite Gibbins et al., 2004 10 Hanmer, Sudbury Basin Mines Cu, Pb, Zn Ontario Mineral Deposit Inventory 11 Jenkins, H. (Placer), Vermilion Valle Au Ontario Mineral Deposit Inventory 12 Sheppard, Shepherd, Davis Ni, Cu Ontario Mineral Deposit Inventory 13 Sheppard property Ni, Cu Dressler, 1984 14 Sir Mortimer Davis, Track-Davis Ni, Cu, PGE Ontario Mineral Deposit Inventory 15 Kenn Holdings And Mining Cu, Ni Ontario Mineral Deposit Inventory 16 Neelon township NW Ni Ontario Mineral Deposit Inventory 17 West Bay Ni, Cu Ontario Mineral Deposit Inventory 18 Onwatin placer, Capreol township plac Au Ontario Mineral Deposit Inventory 19 Malbeuf and Martin Ni, Cu Ontario Mineral Deposit Inventory 20 Pyrite Gibbins et al., 2004 21 Zn Gibbins et al., 2004 22 Kirkwood FW showing Cu, Ni, PGE 23 Segway Cu, Ni, PGE FNX Mining Inc 24 Kirkwood mine Ni, Cu Dressler, 1984 25 Leclerk Ni, Cu Ontario Mineral Deposit Inventory 26 Ni, Cu Dressler, 1984 27 Quartz Gibbins et al., 2004 28 McConnell offset Ni, Cu Ames et al., 2003 29 Executive Neelon Cu, Ag Ontario Mineral Deposit Inventory 30 Waddell Lake, Cleveland Copper Corp. Ni, Cu Ontario Mineral Deposit Inventory 31 Garson mine Ni, Cu, PGE Dressler, 1984 32 Cu Gibbins et al., 2004 33 Zn, Cu, Pb Gibbins et al., 2004 34 West Bay roadside Cu, Ni Ontario Mineral Deposit Inventory 35 Q, Pd, Pt Gibbins et al., 2004 36 Zn, Pb Gibbins et al., 2004 37 Ni, Cu Dressler, 1984 38 Amy Lake showing no. 1 Cu, Ni, PGE Wallbridge Inc 39 Amy Lake showing no. 2 Cu, Ni, PGE Wallbridge Inc 40 Capre property Ni, Cu Dressler, 1984 41 Ni, Cu Dressler, 1984 42 Victor Main/Deep Ni, Cu, PGE Ames et al., 2003 43 Nickel Rim depth Ni, Cu, PGE Ames et al., 2003 44 Victor mine Ni, Cu Ames et al., 2003 45 Nickel Rim mine Ni, Cu, PGE Dressler, 1984 46 Falconbridge mine Ni, Cu, PGE Dressler, 1984 47 Nickel Rim South Ni, Cu, PGE Ames et al., 2003 48 Falconbridge East mine Ni, Cu Dressler, 1984 49 U Dressler, 1984 50 MacLennan mine Ni, Cu, PGE Dressler, 1984 51 Cryderman property Ni, Cu Dressler, 1984 52 Massey Bay U Ontario Mineral Deposit Inventory 53 U Dressler, 1984 54 Ni, Cu Dressler, 1984 55 Norduna mine Ni, Cu Dressler, 1984 56 Pershland Ni, Cu Ontario Mineral Deposit Inventory 57 Copper Prince Resources Inc. Cu, Au Dressler, 1984 58 Chevrette, E. U Ontario Mineral Deposit Inventory 59 Cu, Zn, Ni, Au, Ag Dressler, 1984 60 Skead mine Au Dressler, 1984 61 kyanite Dressler, 1984 62 Cu, Zn, Ni, Au, Ag Dressler, 1984 63 Falcon, Beckley Au Ontario Mineral Deposit Inventory 64 Hodden Grey Cu Ontario Mineral Deposit Inventory 65 Wanapitei Au Ontario Mineral Deposit Inventory 66 Sheppard gold mine (Misnomer) Au Ontario Mineral Deposit Inventory 67 Mackenzie Au, Cu, Ni Ontario Mineral Deposit Inventory 68 Manchester Ni, Cu Ames et al., 2003 69 Bonanza mine Au, q Dressler, 1984 70 Maclennan township Au Ontario Mineral Deposit Inventory 71 Foisey Ni, Cu Ontario Mineral Deposit Inventory

0361-0128/98/000/000-00 $6.00 1060 GEOLOGY OF THE GIANT SUDBURY MINING CAMP, ONTARIO, CANADA 1061

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

72 Midway Energy and Mines Cu, Fe, S Easton and Murphy, 2000 73 Street occurrence 4 Cu Easton and Murphy, 2000 74 Street occurrence no. 1 Cu, Fe, S Easton and Murphy, 2000 75 Street occurrence no. 2 Au, Cu Easton and Murphy, 2000 76 Prosco Mines Limited Cu, U Ontario Mineral Deposit Inventory 77 West Side outlet bay Ni, Cu Ontario Mineral Deposit Inventory 78 Street occurrence no. 6 Cu, Fe, S Easton and Murphy, 2000 79 Au Dressler, 1984 80 Moose Rapids Ni, Cu Ontario Mineral Deposit Inventory 81 Potvin Fe, S Easton and Murphy, 2000 82 Scadding Au Ontario Mineral Deposit Inventory 83 Au Dressler, 1984 84 Au, Cu Dressler, 1984 85 Boulanger-Potvin Au, Cu, Fe, S Easton and Murphy, 2000 86 Gordon Au Ontario Mineral Deposit Inventory 87 Red Rock mine Au Dressler, 1984 88 Mid-Continental Au Ontario Mineral Deposit Inventory 89 Glade Au, Cu, Ni, Ag, Co Ontario Mineral Deposit Inventory 90 Au Dressler, 1984 91 Street occurrence no. 2a garnet, verm Easton and Murphy, 2000 92 Street occurrence no. 2b garnet, ky Easton and Murphy, 2000 93 Street occurrence no. 2c garnet Easton and Murphy, 2000 94 Street occurrence no. 8 Au, Cu, As Easton and Murphy, 2000 95 Street occurrence Cu Easton and Murphy, 2000

NTS Sheet 041I11 1 Pyrite Gibbins et al., 2004 2 Ni, Cu Dressler, 1984 3 Siderite Gibbins et al., 2004 4 Zn, Cu Gibbins et al., 2004 5 Zn, Cu Gibbins et al., 2004 6 Sudbury Elbow Cu, Pb, Zn, Ag, Au Ontario Mineral Deposit Inventory 7 Canada Radium, Pacemaker Mines and Oils As Ontario Mineral Deposit Inventory 8 Simmons Pb, Cu Ames and Gibson, 2004d 9 Zn Gibbins et al., 2004 10 Cu Gibbins et al., 2004 11 Zn, Pb, Cu Gibbins et al., 2004 12 A & M Peperite Ames, 1999 13 Hardy pit Ni, Cu Dressler, 1984 14 Py Gibbins et al., 2004 15 Boundary mine Ni, Cu Dressler, 1984 16 Cu, Ni, Pb Dressler, 1984 17 Morley Zn, Pb, Cu Gibbins et al., 2004 18 Onaping mine Ni, Cu Ames et al., 2003 19 TT showing Zn Gray, 1995 20 Levack mine Ni, Cu Dressler, 1984 21 North trench Zn Gray, 1995 22 Dowling Ni, Cu, PGE Ames et al., 2003 23 Onaping depth Ni, Cu Ames et al., 2003 24 2 Pb, Zn, Cu Gibbins et al., 2004 25 Craig mine Ni, Cu Ames et al., 2003 26 LW showing Zn, Cu, As Gray, 1995 27 3 Zn, Cu, Pb Gibbins et al., 2004 28 Anthraxolite 1 C Dressler, 1984 29 McCreedy West mine Ni, Cu, PGE Ames et al., 2003 30 4 Zn, Cu Gibbins et al., 2004 31 Fecunis mine Ni, Cu Dressler, 1984 32 Cu Gray, 1995 33 Vermilion-Whitewater Zn, Pb, Cu, Au, Dressler, 1984 34 5 Zn, Cu Gibbins et al., 2004 35 North mine Ni, Cu Ames et al., 2003 36 Cow Lake Zn, Cu Ames and Gibson, 2004e 37 McNunes Zn, Cu, Pb Ames and Gibson, 2004e 38 McCreedy East mine Ni, Cu, PGE Ames et al., 2003 39 Strathcona mine Ni, Cu, PGE Dressler, 1984 40 Fraser mine Ni, Cu, PGE Ames et al., 2003 41 Onex shaft Ni, Cu Ontario Mineral Deposit Inventory 42 10 Zn, Cu, Pb Gibbins et al., 2004 43 Coleman mine Ni, Cu, PGE Ames et al., 2003

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TABLE 1. (Cont.)

Location no. Name Commodity Source of data

44 Gordon Lake Road Peperite Ames, 1999 45 Sturdy Mines Ltd. Zn, Pb, Cu Dressler, 1984 46 11 Cu, Zn, Pb Gibbins et al., 2004 47 12 Zn, Cu Gibbins et al., 2004 48 Longvack mine Ni, Cu Ames et al., 2003 49 Lower Coleman Ni, Cu Ames et al., 2003 50 Barnet Cu, Ni, PGE Ames et al., 2003 51 13 Zn Gibbins et al., 2004 52 9 Zn, Cu Gibbins et al., 2004 53 Pb, Ag, Cu Gibbins et al., 2004 54 Big Levack Ni, Cu Dressler, 1984 55 Fraser-Morgan Ni, Cu Ames et al., 2003 56 14 Zn Gibbins et al., 2004 57 15 Cu, Zn Gibbins et al., 2004 58 Sudbury midzone Cu, Pb, Zn Ontario Mineral Deposit Inventory 59 Au Gibbins et al., 2004 60 Rudy’s Lake Cu, Fe Ontario Mineral Deposit Inventory 61 Ni, Cu Dressler, 1984 62 Anthraxolite 2 C Dressler, 1984 63 16 Zn, Cu Gibbins et al., 2004 64 River shaft Zn, Pb, Cu, Au, Dressler, 1984 65 17 - Ryan Zn, Cu, Pb Gibbins et al., 2004 66 Errington No. 1 mine Zn, Pb, Cu, Ag Dressler, 1984 67 Hamilton F Cu Ontario Mineral Deposit Inventory 68 18 Zn, Cu, Pb, Au Gibbins et al., 2004 69 Northwest Balfour Pb, Zn Ontario Mineral Deposit Inventory 70 Quartz Gibbins et al., 2004 71 Vermilion River, lot 8, Con V Cu, Pb, Zn Ontario Mineral Deposit Inventory 72 Errington no. 2 mine Zn, Pb, Cu, Ag Dressler, 1984 73 Balfour, lot 7, Conc VI Cu, Pb, Zn, Au Ontario Mineral Deposit Inventory 74 Limerick Cu, Zn Ames and Gibson, 2004a 75 Quartz Gibbins et al., 2004 76 Zn, Cu, Pb Gibbins et al., 2004 77 Irwin Zn, Pb, Cu, Au, Dressler, 1984 78 Tournigy Zn, Cu Paakki, 1992 79 20 Zn, Cu Gibbins et al., 2004 80 North-East Balfour Cu, Pb, Zn Ontario Mineral Deposit Inventory 81 Errington no. 3 Zn, Pb, Cu, Au, Dressler, 1984 82 Moore Lake Pb, Zn Ontario Mineral Deposit Inventory 83 WD 248 Ni, Cu Ames et al., 2003 84 WD 233 property Ni, Cu Dressler, 1984 85 Whitewater Lake Cu Ontario Mineral Deposit Inventory 86 Bowell Ni, Cu Ames et al., 2003 87 Cu Gibbins et al., 2004 88 Zn Gibbins et al., 2004 89 Rand Creek, Foy offset Ni, Cu Ontario Mineral Deposit Inventory 90 Zn, Cu Gibbins et al., 2004 91 WD 236 Ni, Cu Dressler, 1984 92 WD 212 property Ni, Cu Dressler, 1984 93 WD 152 Ni, Cu Ames et al., 2003 94 Nickel Lake Ni, Cu Ames et al., 2003 95 WD 237 property Ni, Cu Dressler, 1984 96 WD 150 Ni, Cu Dressler, 1984 97 WD 155 Ni, Cu Ames et al., 2003 98 Zn, Cu Gibbins et al., 2004 99 Zn, Cu Gibbins et al., 2004 100 Zn, Cu Gibbins et al., 2004 101 WD 229 Ni, Cu Ames et al., 2003 102 Prue, Proulx, Nelson Lake Zn, Cu Dressler, 1984 103 Cu, Zn Gibbins et al., 2004 104 WD 209 Ni, Cu Dressler, 1984 105 Lady Violet mine Ni, Cu Ontario Mineral Deposit Inventory 106 Foisey Cu, Pb, Zn Ontario Mineral Deposit Inventory 107 Cu, Zn Gibbins et al., 2004 108 Elsie Ni, Cu Ontario Mineral Deposit Inventory 109 Murray mine Ni, Cu Dressler, 1984 110 Discovery site Ni, Cu Ontario Mineral Deposit Inventory 111 McKim mine Ni, Cu Ames et al., 2003 112 North Range shaft Ni, Cu Dressler, 1984

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TABLE 1. (Cont.)

Location no. Name Commodity Source of data

113 Ni, Cu Dressler, 1984 114 Ni, Cu Dressler, 1984 115 Zn, Cu Gibbins et al., 2004 116 Zn Gibbins et al., 2004 117 Ni, Cu Dressler, 1984 118 Blezard Lot 8, Con Ii Ni, Cu Ontario Mineral Deposit Inventory 119 Zn, Pb, Cu Gibbins et al., 2004 120 Junior Frood Ni, Cu Ontario Mineral Deposit Inventory 121 Cameron mine (misnomer) Ni Ontario Mineral Deposit Inventory 122 Blezard-Val Caron Cu, Pb, Zn Ontario Mineral Deposit Inventory 123 Little Stobie mine Ni, Cu, PGE Ames et al., 2003 124 Frood mine Ni, Cu, PGE Ames et al., 2003 125 Zn, Cu, Pb Gibbins et al., 2004

NTS Sheet 041I12 1 Moore And Johns Cu Ontario Mineral Deposit Inventory 2 Balboa, Pumphouse Creek, Balboa Uranium Mines Th, U Ontario Mineral Deposit Inventory 3 Alcourt Mines U Ontario Mineral Deposit Inventory 4 Dumont Cu Ontario Mineral Deposit Inventory 5 Mousseau Lake Zn Ontario Mineral Deposit Inventory 6 Fe, Cu Dressler, 1984 7 Camp Ten Lake Cu Ontario Mineral Deposit Inventory 8 Benson Lake Magnetite Mt Ontario Mineral Deposit Inventory 9 Trill Deep Ni, Cu Ames et al., 2003

NTS Sheet 041I13 1 Moncrieff sulfide no. 11 Ni Ontario Mineral Deposit Inventory 2 Moncrieff Tp sulfide Ni Ontario Mineral Deposit Inventory 3 Moncrieff Creek Mo, Cu. Pb, Zn Ontario Mineral Deposit Inventory 4 Tracanelli Co, Ni, Au, Bi, Cu Ontario Mineral Deposit Inventory 5 Hollinger U Ontario Mineral Deposit Inventory 6 Munster sulfide Cu, Ni Ontario Mineral Deposit Inventory 7 Moncrieff sulfide no. 7 Ni Ontario Mineral Deposit Inventory 8 Munster drilled sulfide Ni Ontario Mineral Deposit Inventory 9 North West Hess township sulfide Magnetite Ontario Mineral Deposit Inventory 10 Munster township Magnetite Ontario Mineral Deposit Inventory 11 Geneva Lake mine Zn, Pb, Ag, Au Dressler, 1984 12 Central Hess township Au Ontario Mineral Deposit Inventory 13 Zn, Pb, Cu, Ag Dressler, 1984 14 Fe Dressler, 1984 15 Geneva Lake prospect As, Pb, Ba Ontario Mineral Deposit Inventory

NTS Sheet 041I14 1 Eams Cu Ontario Mineral Deposit Inventory 2 Ni, Cu Dressler, 1984 3 Harty township Cu Ontario Mineral Deposit Inventory 4 Cartier regional Ni, Cu Ontario Mineral Deposit Inventory 5 South Lake, Botha, Sandfly Lake Cu Ontario Mineral Deposit Inventory 6 Ni, Cu Dressler, 1984 7 Sandcherry Lake Ni, Cu Ontario Mineral Deposit Inventory 8 Ni, Cu Dressler, 1984 9 Holmstrom, Venetian Lake Ag, Cu, Pb, Zn, Au Ontario Mineral Deposit Inventory 10 Nickel offset mine Ni, Cu, PGE Dressler, 1984 11 WD 250 Ni, Cu Ames et al., 2003 12 Mcgrindle Lake, Botha, Mccrindle Cu Ontario Mineral Deposit Inventory 13 WD 234 Ni, Cu Ames et al., 2003 14 Crazy Creek Ni, Cu Ames et al., 2003 15 WD 228 Ni, Cu Dressler, 1984 16 Copenhagen mine Cu, Pb, Ni Dressler, 1984 17 WD 13 Ni, Cu Ames et al., 2003 18 South zone Cu, Ni, PGE Wallbridge Inc 19 Broken Hammer zone Cu, Ni, PGE Wallbridge Inc 20 WD 16 Ni, Cu Dressler, 1984

NTS Sheet 041I15 1 Vermilion River Au Dressler, 1984 2 Au Dressler, 1984 3 Vermillion Placer Gold, Milnet area placer gold Au Ontario Mineral Deposit Inventory 4 Concor-Chibougamau, Milnet area placer gold Au Ontario Mineral Deposit Inventory

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TABLE 1. (Cont.)

Location no. Name Commodity Source of data

5 Harold Barry dike Cu Ontario Mineral Deposit Inventory 6 Ni, Cu Dressler, 1984 7 Zn, Cu, Ni Dressler, 1984 8 Ni, Cu Dressler, 1984 9 Brown Gold Au, Ag, Pb Ontario Mineral Deposit Inventory 10 Ni, Cu Dressler, 1984 11 Norman West Ni, Cu Ames et al., 2003 12 Se Island Lk Cu Ontario Mineral Deposit Inventory 13 New Dominion Ni, Cu Ontario Mineral Deposit Inventory 14 Golden Pine property Au, Ni Ontario Mineral Deposit Inventory 15 Aro, George, Leschishin property Ag, Au Ontario Mineral Deposit Inventory 16 Norpick Gold Mines N Shore Au Ontario Mineral Deposit Inventory 17 Whistle mine Ni, Cu Dressler, 1984 18 Ni, Cu Dressler, 1984 19 Ni, Cu Dressler, 1984 20 Parkin marble Marble Ontario Mineral Deposit Inventory 21 Lot 6 Con 2 Parkin, Miron, T. Ag, Au, Cu, Pb Ontario Mineral Deposit Inventory 22 Decade, Mowat Creek Ag, Au, Pb, Cu, Zn Ontario Mineral Deposit Inventory 23 Parkin, J. Mataris, Mowat Creek Au Ontario Mineral Deposit Inventory 24 Ni, Cu Dressler, 1984 25 Ni, Cu Dressler, 1984 26 Pt, Ag, Au Dressler, 1984 27 Podolsky mine (Norman ) Cu, Ni, PGE Ames et al., 2003 28 Falmac zinc Zn, Cu Ontario Mineral Deposit Inventory 29 Milnet (Jonsmith) Ni, Cu, PGE Ames et al., 2003 30 W.G. Peacock, R.M. Elliot, Brady,J. Au, Cu, Ni, Ag, Co Ontario Mineral Deposit Inventory 31 Post Creek Cu Ontario Mineral Deposit Inventory 32 Lot 4 Con 2 Parkin Au Ontario Mineral Deposit Inventory 33 Free Gold, Mataris, J. Au Ontario Mineral Deposit Inventory 34 Ironco Iron & Smelting Cu Ontario Mineral Deposit Inventory 35 Mataris, J, Brady, J. Au Ontario Mineral Deposit Inventory 36 J. Mataris lot 1, Con 1 As Ontario Mineral Deposit Inventory 37 Rathbun township Fe Dressler, 1984 38 Dobson, Charles, Bennett, W.S., Bennett, G. Au Ontario Mineral Deposit Inventory 39 Au Dressler, 1984 40 Rathbun Lake Cu, Ni, Pd, Pt, Au Dressler, 1984 41 Thomas Lake Au Ontario Mineral Deposit Inventory 42 Crystal mine Au Dressler, 1984

Note: The location categorized according to each NTS sheet is numbered from west to east (Map 1, inset figure) Refer to NTS reference inset map; annotated on map according to status and colored according to commodity towards it; the orientation of the axes cones displayed on Map Igneous Complex impact melt, a lower crustal melt that crys- 1 plunge both upward and downward. The recent discovery tallized between 1849.53 ± 0.21 and 1849.11 ± 0.19 Ma of the iridium anomaly in the upper 800 m of crater-fill brec- (Table 2). This highly precise dating provides an innovative cias (Dowling member of the Onaping Formation: Mungall et tool for constraining metallogenic events to less than 1 m.y. al., 2004; Ames et al., 2005) and the recognition of out-of- Understanding the pre-, syn- (ca. 1850 Ma) and post-impact crater distal ejecta in Ontario, Michigan, and Minnesota (Ad- timing of these events is crucial for effective mineral explo- dison et al., 2005; Pufahl et al., 2007) further support the im- ration in the Sudbury region. For example, among the pact origin of the Sudbury structure (Figs. 3, 4). Iridium youngest post-impact events to have affected the Sudbury Ni- anomalies in the proximal ejecta of the Onaping Formation in Cu-PGE orebodies was the intrusion of the 590 Ma Grenville the Whitewater Group (Mungall et al., 2004; Ames et al., diabase dike swarm which locally remobilized sulfide ores and 2005; Ames and Farrow, 2007) and distal ejecta of the Baraga cut the orebodies at the Clarabelle open pit, Copper Cliff off- Group (Pufahl et al., 2007) define a distinct timeline at 1850 set, Strathcona mine, and Levack Embayment. This magma- Ma across the midcontinent Paleoproterozoic region. tism was associated with Cambro-Ordovician extension along The compilation and integration of over 80 U-Pb dates the Ottawa-Bonnechere graben (Fedorowich et al., 2006). At (Table 2, Map 1, Figs. 5, 6), which include the age distribu- 13 to 5 Ma, Tertiary brines also locally remobilized the Sud- tion of major depositional, intrusive, tectonometamorphic, bury sulfide ores, producing galena-sphalerite–bearing veins hydrothermal, and multiple meteorite impact events, span at the McCreedy and Lindsley mines (Marshall et al., 1999). the range from Neoarchean through to Neogene. Recent ad- The Sudbury structure comprises shocked and brecciated vances in U-Pb zircon dating, involving submillion-year age footwall rocks, the igneous rocks of the Sudbury Igneous resolution (Davis, 2008), provide unprecedented constraints Complex and offset dikes, and breccias of the Onaping For- on the cooling history of the noritic phase of the Sudbury mation. The salient stratigraphic components are illustrated

0361-0128/98/000/000-00 $6.00 1064 GEOLOGY OF THE GIANT SUDBURY MINING CAMP, ONTARIO, CANADA 1065

81o 38’ 46o 53’20”

Tyrone

Whistle-Parkin Pele offset dykes

Foy 37 Ma Wanapitei impact Hess SIC crater SCF ping Fm. FLF Ona

Onwatin Fm. PCDZ Fm.

Chelmsford

Ministic u Zn-Pb-C Manchester Onaping Intrusion SRSZ

Trill N GBFFGBF GB CF GBF Copper Cliff

MF

10 km Worthington 46o 21’20” o Nipissing diabase 80 37’ GRENVILLE PROVINCE Granite Undifferentiated HURONIAN SUPERGROUP Cobalt Group SOUTHERN PROVINCE Quirke Lake Group MESOPROTEROZOIC Hough Lake Group Chief Lake Igneous Complex Upper Elliot Lake Group: metasedimentary rocks PALEOPROTEROZOIC Lower Elliot Lake Group: metavolcanic rocks SUDBURY STRUCTURE East Bull Lake igneous suite Whitewater Group: post-impact sediments SUPERIOR PROVINCE Ni-Cu-Co-Pt-Pd-Au mineralization NEOARCHEAN Whitewater Group: fallback, hydroclastitic Cartier Batholith and plume collapse breccias Mafic metavolcanic, metasedimentary rocks Sudbury igneous complex and related igneous rocks Levack Gneiss Complex

FIG. 2. Geologic map of the Sudbury mining district simplified from Map 1 (in pocket) shows the location of the proxi- mal impactites (units labelled), footwall rock types, and mineralization of the Sudbury impact structure. Abbreviations: PCDZ = Pumphouse Creek deformation zone, SCF = Sandcherry Creek fault, FLF = Fecunis Lake fault, MF = Murray fault, CF = Creighton fault, SRSZ = South Range shear zone (hatched area), GBF = Grenville Front boundary fault. in Figure 7. The erosional remnant of an impact basin, the cases specific to one company, that has developed since the Sudbury Igneous Complex, and various breccias also define a first discovery of Ni-Cu ore in 1883. Local names are indi- structural basin of a regional periclinal fold which down- cated in parentheses in the legend (e.g., Sudbury Igneous folded and thus preserved the Whitewater group in the Complex “norite” is a quartz monzogabbro-quartz gabbro). A center of the structural basin. The descriptions of units rep- photo library is available for the important rock types in the resented on Map 1 avoid genetic or local terminology, in some Sudbury structure, including shatter cones, Sudbury breccia,

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TABLE 2. U-Pb Isotope

U-Pb no. Age (Ma) UTM_E UTM_N Map 1, Figs. 5 and 6 Sample no. Zone 17, NAD 27 Rock type Unit location

1 2657 ± 5 CLA-93-065 507000 5180393 Monzodiorite LGC 2 1849.1 ± 1.1 C-94-2 509086 5179520 Olivine melanorite pod in sublayer Whistle Embayment 3 1848.3 ± 1.0 C-94-5 509086 5179520 Melanorite pod in sublayer Whistle Embayment 4 1848.4 ± 1.4 C-94-7 509086 5179520 Metapyroxenite inclusion in sublayer Whistle Embayment 5 1848.1 ± 1.8 C-94-8 509086 5179520 Sublayer norite matrix Whistle Embayment 6 1848.7 ± 1.1 C-94-9 509086 5179520 Diabase Whistle Embayment 7 1852 +4/-3 Foy-4 489818 5176477 Diorite (contact rock) Foy offset 8 1852 +4/-3 Foy-1 490206 5176070 Diorite dike Foy offset 9 1852 +4/-3 Foy-2 489774 5176473 Diorite dike Foy offset 10 1852 +4/-3 Foy-3 489437 5176737 Diorite dike Foy offset 11 2635 ± 5 Lev-1 490049 5175874 Dioritic to monzonitic gneiss LGC 12 2635 ± 5 Lev-2 490070 5175875 Dioritic to monzonitic gneiss LGC 13 1848.4 ± 1 AV-J8 498828 5174642 Albitized Sandcherry member breccia Lower Onaping Formation 14 2644 ± 3 CLA-93-027 516111 5173126 Massive granite LGC 15 2646 ± 2 CLA-93-032B 513452 5172021 Diatexite mobilizate LGC 16 2645 +7/-4 CLA-93-009A 515167 5168835 Granitic leucosome LGC 17 1850.0 +3.4/-2.4 Mafic norite 473492 5168775 Mafic norite SIC (North Range) 18 2642 ± 1 CLA-93-186 459702 5167882 Granite Cartier granite 19 2647 ± 2 TK82-10 463040 5165729 Pegmatoid LGC 20 2668 +3/-2 CLA-93-175 462880 5165007 Granodiorite LGC 21 2661 ± 2 CLA-93-167A 465734 5163376 Tonalite diatexite LGC 22 1849.53 ± 0.21 Felsic norite 466935 5162551 Felsic norite SIC (North Range) 23 1848.9 +4.0/-2.7 Felsic norite 466935 5162551 Felsic norite SIC (North Range) 24 1849.6 +3.4/-3.0 Felsic norite 466935 5162551 Felsic norite SIC (North Range) 25 2441 ± 3 SPA89-08a 517730 5162135 Gabbro Falconbridge Twp. intrusion 26 ca. 2700 SPA89-08a 517730 5162135 Gabbro Falconbridge Twp. intrusion 27 986 ± 30 SPA89-08a 517730 5162135 Gabbro Falconbridge Twp. intrusion 28 1850.5 ± 3.0 TK82-15 470758 5161395 Granophyre SIC (North Range) 29 2711 ± 7 TK82-14 470447 5160084 Granite xenolith Lower Onaping Formation 30 1836 ± 14 TK82-14 470447 5160084 Granite xenolith Lower Onaping Formation 31 2679 ± 16 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation 32 2686 ± 2 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation 33 2695 ± 3 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation 34 2708 ± 8 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation 35 2719 ± 4 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation 36 2647 ± 1 CLA-93-339 460167 5157468 Mafic gneiss LGC 37 1848 ± 4 02-AV-852 500672 5157455 Aplite Dike, cutting norite SIC

38 2668 ± 5 CLA-93-336 459467 5157403 Granodiorite LGC 39 1849.11 ± 0.19 Black norite 501047 5156892 Mafic norite SIC (South Range) 40 1850.0 ± 1.3 Black norite 501047 5156892 Mafic norite SIC (South Range) 41 1849.4 +1.9/-1.8 Black norite 501047 5156892 Mafic norite SIC (South Range) 42 1850.1 ± 11.2 BL-7 500500 5156060 Sheared norite Norite/SIC

43 1815 ± 15 BL-7 500500 5156060 Sheared norite TLSZ/SIC (South Range) 44 1658 ± 68 BL-7 500500 5156060 Sheared norite TLSZ/SIC (South Range) 45 1850 ± 1 S81-8 495998 5155562 Granite dike dike, SIC 46 1720 +36/-19 C3 528870 5154060 Biotite-hornblende granite Street Twp. 47 2475 +25/-15 C3 528870 5154060 Biotite-hornblende granite Street Twp. 48 987 ± 9 C3 528870 5154060 Biotite-hornblende granite Street Twp. 49 932 ± 6 C3 528870 5154060 Biotite-hornblende granite Street Twp. 50 1052 ± 19 C4 524997 5153551 OPX-hornblendite East Bull Lake intrusive suite 51 1471 ± 10 C4 524997 5153551 OPX-hornblendite East Bull Lake intrusive suite 52 2468 ± 5 C4 524997 5153551 OPX-hornblendite East Bull Lake intrusive suite 53 987 ± 3 C2 528870 5154060 Granitic leucosome Street Twp. 54 995 ± 3 C2 528870 5154060 Granitic leucosome Street Twp. 55 989 ± 2 C1 528870 5154060 Pegmatite vein Street Twp. 56 1701 ± 3.6 SC-5 Scadding mine 526624 5163735 Albitized metasedimentary rock Huronian Supergroup 57 1699 ± 3.6 Sheppard property 520934 5170771 Albitized metasedimentary rock Huronian Supergroup 58 2477 ± 9 Murray granite 497422 5152998 Granite Murray pluton 59 1850 ± 3 Murray granite 497422 5152998 Granite Murray pluton 60 2446 ± 7 96DM 70 523110 5151775 Migmatitic granite Grenville Front

61 2296.9 ± 5.8 AV-162A 469188 5151337 Quartz diorite lobe in peperite Upper Onaping Formation 62 2602.8 ± 3.3 AV-162B 469188 5151337 Quartz diorite lobe in peperite Upper Onaping Formation 63 2616 ± 5.7 AV-162C 469188 5151337 Quartz diorite lobe in peperite Upper Onaping Formation 64 2628.6 ± 3.2 AV-162D 469188 5151337 Quartz diorite lobe in peperite Upper Onaping Formation 65 2450 +25/-10 C81-19 496330 5148472 Rhyolite Copper Cliff Formation

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Data Across the Map Area

Interpretation Mineral Reference Comments

Igneous age Zrn N. Wodicka (unpub.) Igneous age Zrn/Bdy Corfu and Lightfoot, 1996 Igneous age Zrn/Bdy Corfu and Lightfoot, 1996 Igneous age Zrn Corfu and Lightfoot, 1996 Igneous age Zrn/Bdy Corfu and Lightfoot, 1996 Igneous age Zrn Corfu and Lightfoot, 1996 Igneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samples Igneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samples Igneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samples Igneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samples Igneous age Zrn Ostermann et al., 1996 UI of discordia line defined by data from the two LGC samples Igneous age Zrn Ostermann et al., 1996 UI of discordia line defined by data from the two LGC samples Hydrothermal event Ttn Ames et al., 1998 Recalculated age based on weighted average age of 5 titanite fractions Igneous age Zrn N. Wodicka (unpub.) Migmatization Zrn N. Wodicka (unpub.) Migmatization Zrn N. Wodicka (unpub.) Igneous age Zrn Krogh et al., 1984 Igneous age Zrn Meldrum et al., 1997 Metamorphism Zrn Krogh et al., 1984 Igneous age Zrn N. Wodicka (unpub.) Igneous age Zrn N. Wodicka (unpub.) Igneous age Zrn Davis, 2008 Sample from Krogh et al. (1982, 1984) reanalyzed with new TE-TIMS technique Igneous age Zrn Krogh et al., 1984 Igneous age Zrn Krogh et al., 1982 Igneous age Zrn Prevec and Baadsgaard, 2005 Inheritance Zrn Prevec and Baadsgaard, 2005 Episodic Pb loss Zrn Prevec and Baadsgaard, 2005 Igneous age Bdy Krogh et al., 1984 Igneous age Zrn Krogh et al., 1984 UI of discordia line defined by data from LGC and Onaping Formation samples Shock-induced Pb loss Zrn Krogh et al., 1984 LI of discordia line defined by data from LGC and Onaping Formation samples Xenocryst age Zrn Krogh et al., 1996 Xenocryst age Zrn Krogh et al., 1996 Xenocryst age Zrn Krogh et al., 1996 Xenocryst age Zrn Krogh et al., 1996 Xenocryst age Zrn Krogh et al., 1996 Metamorphism Zrn N. Wodicka (unpub.) Igneous age Zrn A. Galley and O. van Breemen (unpub.) Igneous age Zrn N. Wodicka (unpub.) Igneous age Zrn Davis, 2008 Sample from Krogh et al. (1982, 1984) reanalyzed with new TE-TIMS technique Igneous age Zrn Krogh et al., 1984 Igneous age Zrn Krogh et al., 1982 Igneous age Zrn B. Lafrance and S. Kamo (unpub.) Metamorphism Ttn Bailey et al., 2004 Shear zone formation Ttn Bailey et al., 2004 Maximum igneous age Zrn Krogh et al., 1984 Interpreted maximum age based on age of norite cut by the granitic dike Metamorphism Ttn Corfu and Easton, 2000 Igneous age Zrn Corfu and Easton, 2000 Metamorphism Ttn Corfu and Easton, 2000 Cooling Ap Corfu and Easton, 2000 Metamorphism? Zrn Corfu and Easton, 2000 Metamorphism Zrn Corfu and Easton, 2000 Igneous age Zrn Corfu and Easton, 2000 Partial melting Zrn Corfu and Easton, 2000 Inheritance? Zrn Corfu and Easton, 2000 Deformation Zrn Corfu and Easton, 2000 Hydrothermal event Mnz Schandl et al., 1994 Hydrothermal event Mnz Schandl et al., 1994 Igneous age Zrn Krogh et al., 1996 Previous age of 2388 +20/-13 Ma (Krogh et al., 1984) may be erroneously young Shock-induced Pb loss? Ttn Krogh et al., 1996 Igneous age Zrn A. Davidson and O. van Breemen (unpub.) Xenocryst age Zrn Ames et al., 1998 Minimum age (9.1% discordant fraction) Xenocryst age Zrn Ames et al., 1998 Xenocryst age Zrn Ames et al., 1998 Xenocryst age Zrn Ames et al., 1998 Minimum age (3.7% discordant fraction) Volcanism Zrn Krogh et al., 1984

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TABLE 2.

U-Pb no. Age (Ma) UTM_E UTM_N Map 1, Figs. 5 and 6 Sample no. Zone 17, NAD 27 Rock type Unit location

66 1849.8 ± 2.0 C-94-12 494584 5148091 Quartz diorite Copper Cliff offset 67 1747 +12/-6 92DM 169 513250 5145525 Granite dike Wanapitei Complex

68 1747+6/-5 SPA-89-31 515250 5144765 Norite Wanapitei Complex 69 1859 ± 13 Spa-88-56a 464000 5141600 Gabbro Drury Twp. intrusion 70 1464 +2/-1 92DM 192a 503000 5138175 Biotite granite Chief Lake complex

71 1749 +12/-8 92DM 247 501375 5138150 Biotite granodiorite Eden Lake suite

72 506 ± 4 JF-95-65 473718 5168688 Diabase dike Fraser-Strathcona mine 73 1815.9 ± 25.2 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine 74 1817.7 ± 5.7 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine 75 1818.8 ± 9.4 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine 76 1832.2 ± 7.1 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine 77 1833.8 ± 6.6 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine 78 1858.7 ± 7.6 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine 79 2333 +33/-22 Creighton granite 487501 5144302 Granite Creighton pluton 80 2415 ± 5 LH98-63 485979 5141839 Porphyritic granite Creighton pluton 81 2376.3 ± 2.3 MS99-50 487759 5146465 Granite Creighton pluton

LGC = Levack gneiss complex, SIC = Sudbury Igneous Complex, TLSZ = Thayer Lindsley shear zone, TE-TIMS = Thermal extraction - thermal ionization mass spectrometry, UI = Upper intercept, LI = Lower intercept All mineral abbreviations are after Kretz (1983) except for Bdy (baddeleyite)

Footwall breccia, Sudbury Igneous Complex and associated Igneous Complex are included on Map 1. Along the basal offset dikes, Onaping intrusion, and Onaping, Vermilion, and contact of the Sudbury Igneous Complex representative dip Onwatin Formations of the Whitewater Group (Ames, measurements are displayed at 10-km intervals. The eco- 2007a). nomic interest in the structural and stratigraphic footwall en- A regional compilation of detailed mapping of the Sudbury vironment of the Sudbury Igneous Complex has resulted in Igneous Complex (Shanks, 1991; Johns, 1996 a, b), new offset several significant geologic discoveries. Map 1 displays the dikes, and dip measurements along the base of the Sudbury recently identified offset dikes (Pele offset, discovered in

94°W90° 86° 82° 78°

Ont Quebec

Mani

Ontario ario 50°N

toba

1000 km 800 km 600 km SUPERIOR PROVINCE Huronian Supergroup Animikie 400 km Group km CCANADAANADA 200 MMinnesotainnesota SSudburyudbur y E UU.S.A..S.A. C 48° IN iimpactmpact V O ROVINCER Lake Superior ssiteite P LEPE ILLL V NNVI E R GGRE

46° Animikie Lak Group MMarquettearquette R Rangeange Hurone SupergroupSupergroup igan Michigan Distal ejecta site Distal ejecta iridium site 44° 0 200 km Proximal ejecta iridium anomaly ake Mich L

FIG. 3. Simplified geologic map of the Proterozoic units in the Great Lakes region of North America, showing the loca- tions of ejecta from Earth’s largest exposed multi-ring impact structure at Sudbury (modified after Ojakangas et al., 2001). Locations of the distal ejecta from the Sudbury impact crater form a chronostratigraphic marker in the Lake Superior region at 1850 Ma. Known sites of the Sudbury iridium anomaly are shown in the proximal ejecta in the plume collapse breccia of the Dowling member, Onaping Formation, and the distal ejecta in Michigan and Minnesota (data from Mungall et al., 2004; Addison et al., 2005; Ames et al, 2005; Cannon and Addison, 2007; Pufahl et al., 2007).

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(Cont.)

Interpretation Mineral Reference Comments

Igneous age Zrn Corfu and Lightfoot, 1996 Igneous age Zrn A. Davidson and O. van Breemen (unpub.) Igneous age Zrn Prevec, 1992 Shock-induced Pb loss? Zrn Prevec and Baadsgaard, 2005 Igneous age Zrn Davidson and van Breemen, 1994 Igneous age Ttn Davidson and van Breemen, 1994 Igneous age Zrn Fedorowich et al., 2006 Magmatic titanite from same dike gives a similar age of 530 ± 21 Ma Xenocryst age Zrn Fedorowich et al., 2006 Xenocryst age Zrn Fedorowich et al., 2006 Xenocryst age Zrn Fedorowich et al., 2006 Xenocryst age Zrn Fedorowich et al., 2006 Xenocryst age Zrn Fedorowich et al., 2006 Xenocryst age Zrn Fedorowich et al., 2006 Igneous age Zrn Frarey et al., 1982 Age, based on unabraded multigrain zircon fractions, may be a minimum Igneous age Zrn Smith, 2002 Data show excess scatter and interpreted age may be a minimum (Smith, 2002) Igneous age Zrn Smith, 2002

N 10 km Offset dikes

. Fm ing ap OOnapingn Fm. plex

y Igneous Com

Sudbur

Impact diamonds Iridium anomaly > 0.40 ppb average 0.57 ppb, n=24 Iridium < 0.30 ppb, average 0.14 ppb, n=28

fallback and Sudbury breccia: pseudotachylite plume collapse breccias post-2000, pre-1984 mapping

melt sheet Shattercones

FIG. 4. Map showing the distribution of proximal Sudbury structure impact features including shocked rocks, impact breccias, melt rocks, and iridium content of impact and post-impact rocks sampled. Parautochthonous impact breccias are displayed on Map 1 (units 34, 35); however, the regional distribution of Footwall breccia (unit 35 on Map 1) is not well known. New mapping by industry of Sudbury breccia (in black) details the shocked basement close to the base of the Sud- bury Igneous Complex.

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Sedimentation/ Intrusive eventsHHydrothermalydrothermal Tectono- Impact Volcanism eeventsvents metamorphism 500 7722 OOttawa-Bonnecherettawa-Bonnechere igneous zircon ggrabenraben ((500-600500-600 MaMa extensionextension metamorphic zircon andand r rifting)ifting) reset zircon igneous zircon/baddeleyite igneous baddeleyite 27 48 Grenvillian 1000 53 55 Orogeny hydrothermal monazite hydrothermal titanite 50 1100 metamorphic titanite reset titanite

1200 ~1.24 Ga Sudbury diabase dikes

11300300

70 51 1500 Chief Lake complex Chieflakian event

1600

44 57 YYavapai-Mazatzalavapai-Mazatzal O Orogenyrogeny 1700 56 Wanapitei complex/ 68 46

(Ma) Eden Lake suite Au 67 71 Whitewater Ni-Cu Shock-induced 1800 Group 43 Pb loss? Age 7-10 22 37 42 ? 66

13 30 59 2 3 456 17 28 39 45 Penokean 69 Sudbury Igneous Complex 1900 Zn-Pb-Cu Orogeny 11850850 M Maa S Sudburyudbury Ni-Cu-PGE iimpactmpact eventevent

2000

~2.22-2.21 Ga Nipissing diabase ? 2200 Ni-Cu-PGE, Ag-Co GGraniteranite Blezardian 2300 Cu, U Huronian ((Murray/Creighton)Murray/Creighton) Supergroup Orogeny 79 MMafic-Ultramaficafic-Ultramafic (East(East B Bullull L Lake)ake) 81 2400 PGE-Cu-Ni ? Early 80 52 47 66 volcanism 25 58 60 2500 ~2.47 Ga Matachewan swarm Rifting Doming/uplift

Cooling/ Late plutonism eiss 2600 exhumation

11-12 gn 14 Cartier granite

eiss Cu-Pb-Zn-Ag 18 mplex gn Tonalite- 15 16 19 36

co

1 vack 20 21 38 ? mplex granodiorite Metamorphism/

2700 Le

co migmatization

vack 29 Tonalite ? Le Benny-Parkin 2800 greenstone belts

FIG. 5. Summary of geochronologic data for the Sudbury area in relation to major tectonic events in the region (Table 2, modified from Ames et al., 2005). Mineralizing events span a significant timeline and include Archean and Proterozoic vol- canogenic massive sulfide, magmatic nickel, and uranium deposits, 1850 Ma impact-related magmatic Ni-Cu-PGE and hy- drothermal Zn-Pb-Cu deposits, and post-impact mesothermal gold mineralization. All dates reported in Table 2 are shown with the exception of xenocrystic, inheritance, and cooling data. Sources for data outside the map area are as follows: Mat- achewan swarm: Heaman (1997); Nipissing diabase: Corfu and Andrews (1986); Noble and Lightfoot (1992); Sudbury dikes: Krogh et al. (1987) and Dudàs et al. (1994). Age ranges for other events without any or very few reported ages are based on field relationships as given in the literature.

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N 1 2-6 10 78, 9 11 12 13 14 15 56

17 16 18 72-78 19 20 21 57 2324 22 28 25-27

29-35 37 38 36 39, 40 41-44 ZONE 45 58, 59 53-55 50-52 46-49 SHEAR 60 61-64

RANGE 66 65 81 SOUTH 67 79 68

80 69

71 70 10 km

FIG. 6. Location of U-Pb geochronology sample sites in the Sudbury area as shown on Map 1. For legend refer to Figure 2. See Table 2 for details of the age data.

2007, and Trill offset, discovered in 2005), as well as exten- deposition of the iridium-bearing units of the overlying Dowl- sions (Ministic, Foy, Parkin, Manchester, Copper Cliff, and ing member (Mungall et al., 2004). Worthington) and revisions of known offset dikes (Lightfoot et al., 1997; Wood and Spray, 1998; Murphy and Spray, 2002; Levack gneiss complex, northern footwall rocks Tuchscherer and Spray, 2002). One of the most conspicuous features of the northern foot- In the early 1990s, collaborative mapping by industry, uni- wall of the Sudbury impact crater is the 0.5- to 5-km-wide ar- versity, and government researchers focused on the impact cuate belt of upper amphibolite to granulite facies rocks of crater fill (Onaping Formation) and the origin and setting of the Neoarchean Levack gneiss complex exposed along the the 6.4 Mt Zn-Pb-Cu deposits at the top of the crater infill. northern rim of the Sudbury Igneous Complex, from Trill This work established the regional stratigraphic subdivisions township to Wanapitei Lake (Map 1). Regional mapping by and characterized the associated regional semiconformable the Geological Survey of Canada (Card, 1994) has shown alteration, structure, and hydrothermal base metal mineral- that this high-grade metamorphic complex comprises domi- ization in the breccias of the Onaping Formation and overly- nantly mafic to intermediate orthogneiss and mafic to felsic ing carbonates of the Vermilion Formation (too thin to show plutonic units, with minor migmatitic paragneiss and locally on Map 1). The Onaping Formation, overlies the melt sheet recognized iron formation. The orthogneiss ranges in age be- that partially assimilated and melted the fallback breccia. The tween 2711 ± 7 and 2668 +3/–2 Ma (Krogh et al., 1984; Wod- andesitic impact melt intruded fallback breccia and formed icka, 1997; N., Wodicka, unpub. data), although Ostermann et hydroclastic breccia complexes in the Sandcherry member, al. (1996) report a distinctly younger age of 2635 ± 5 Ma for Onaping Formation (Ames, 1999; Ames et al., 2002; Ames dioritic to monzonitic gneiss (Table 2). Mildly foliated to un- and Gibson, 2004a). Crater collapse and instability resulted deformed intermediate to felsic plutons yield ages of 2657 ± in the formation of the embayment structures at the base of 5 and 2644 ± 3 Ma. The main phase of upper amphibolite to the Sudbury Igneous Complex during deposition of the On- granulite facies metamorphism and migmatization occurred aping Formation (Ames and Farrow, 2007). Gravitational at crustal depths of 21 to 28 km (James et al., 1991) at about collapse of the basement during deposition of the Onaping 2647 to 2645 Ma (Table 2). This event immediately predated Formation is marked by growth faults, thickness variations in emplacement of the postorogenic, 2642 ± 1 Ma Cartier gran- debris flows, and paleotopographic highs and lows at the ite (Map 1, Fig. 5), a batholith-scale body of monzogranitic to upper contact of the Sandcherry member (Map 1, units 42, granodioritic composition interpreted to have been derived 43). Subsequent plume collapse and reworking resulted in from partial melting, at least in part, of the Levack gneiss

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A. Stratigraphy B. Ore Deposits metalliferous halo Chelmford Fm. Hydrothermal Zn-Pb-Cu Onwatin Fm. 1.85 Ga “VMS” impactites Vermilion Fm. OF Zn-Cu Dowling member { Onaping Cu intrusion debris flow Onaping Fm. SIC Sandcherry member Garson member GROUP WHITEWATER { Contact Ni-Cu-Co granophyre Cu-Ni Footwall quartz gabbro Pt-Pd-Au

norite

footwall SIC MAIN MASS breccia sublayer

Offset Kelly, Sudbury Offset Totten Cu-Ni-Au breccia dike deposits Ag-Pt-Pd inclusion quartz diorite

quartz diorite FOOTWALL ROCKS FOOTWALL radial offset dike

1 km concentric offset dike

1 km

FIG. 7. Generalized stratigraphic columns for the 1850 Ma Sudbury structure illustrating the environments of magmatic- hydrothermal Ni-Cu-PGE and hydrothermal Zn-Pb-Cu ore deposits associated with the Sudbury Igneous Complex. Note the difference in scale on A and B. Contact deposits, are hosted in sublayer and Footwall breccia, proximal to the basal con- tact of the Sudbury Igneous Complex. Footwall precious metal-rich deposits are hosted in Sudbury breccia within ~1.5 km from the Sudbury Igneous Complex. Offset deposits occur in inclusion-bearing quartz diorite along the offset dikes with the most distal offset deposit at ~7 km. complex (Meldrum et al., 1997). The field characteristics and during the Neoarchean, broadly coincident with or immedi- age of the youngest plutonic rocks within the Levack gneiss ately preceding emplacement of the Cartier batholith (Fig. 5; complex, particularly those of the 2644 ± 3 Ma massive gran- e.g., James et al., 1991; Wodicka, 1997). Additional petro- ite (Table 2), suggest that these rocks may represent phases of graphic evidence supports a Neoarchean phase of exhuma- this batholith. tion prior to intrusion of the 2.47 Ga Matachewan dikes A long-standing question regarding the surface exposure (Siddorn and Halls, 2002). Geophysical evidence for a domal- distribution of the Levack gneiss complex is the timing of ex- uplift structure, underlying and orthogonal to the long axis of humation of the high-grade gneissic rocks (e.g., see Prevec et the Sudbury Igneous Complex, recently has been interpreted al., 2005, for a summary). Evidence increasingly points to sig- as resulting from early Paleoproterozoic, ca. 2450 Ma (syn- nificant pre-impact uplift and exhumation of the gneiss com- Huronian) rifting and magmatism in the region (e.g., Prevec plex. U-Pb and 40Ar-39Ar cooling ages, combined with amphi- et al., 2005), but it remains unclear whether or not this domal bolite facies decompression textures and field relationships, structure also contributed to a period of rapid exhumation of suggest that the Levack gneiss complex was initially unroofed the Levack gneiss complex. However, none of these studies

0361-0128/98/000/000-00 $6.00 1072 GEOLOGY OF THE GIANT SUDBURY MINING CAMP, ONTARIO, CANADA 1073 preclude the possibility that the 1850 Ma impact event repre- ultramylonite are progressively developed toward the fault in sents the mechanism responsible for the final exposure and both the footwall and hanging wall of the fault. At Coniston present-day configuration of the previously retrograded gran- the thrust fault is truncated by the vertical Murray fault, the ulite facies rocks. northeastward continuation of which is known as the Wanapitei fault. These field relationships imply that the Murray fault, a The Grenville Front prominent structure with a long pre-Grenvillian history (e.g., The boundary between the Southern and Grenville Card et al., 1972; Farrow and Lightfoot, 2002; Spray et al., provinces known as the Grenville Front trends northeast to 2004), was reactivated during the Grenvillian orogeny. southwest across the southeast corner of the map area (Map 1, Fig. 2). It is defined by a prominent fault across which pre- Mineral Deposits dominantly gneissic rocks at middle to upper amphibolite fa- Sudbury rivals Norilsk as the world’s largest nickel camp, and cies are abruptly juxtaposed against low-grade Huronian Su- it also produces significant amounts of Cu, Co, Pt, Pd, Au, and pergroup rocks (predominantly Mississagi Formation), Ag. The Sudbury mining camp has close to 90 Ni-Cu-PGE Nipissing gabbro, the Chief Lake complex, and undeformed deposits, including 14 currently operating mines, numerous Sudbury dikes. Detailed remapping of the Grenville Front past producers, and several advanced prospects (Fig. 8). during the last 15 years in the vicinity of the town of Coniston Lesser known are the past-producing Zn-Pb-Cu-Ag hy- and in Street township (Map 1) has resulted in an improved drothermal massive sulfide deposits that are situated above understanding of the nature of the front (Davidson, 2001; the Sudbury Igneous Complex (Figs. 7, 8, 9). Over 425 mines Easton and Murphy, 2002, and references therein). South- and occurrences are indicated on Map 1 and listed in Table 1. west of Coniston, the Grenville Front boundary fault is a The surface projections of the historic and current Ni-Cu- moderately to steeply southeast-dipping thrust. Mylonite and PGE and Zn-Pb-Cu mineralization displayed on the map are

N

SIC

10 km

Ni-Cu-Co Occurrence Cu-Ni-Pt-Pd-Au Past Producer Zn-Pb-Cu Producer Au Advanced Cu-Au Prospect

FIG. 8. Mineral deposits of the Sudbury region including pre-, syn-, and post-impact mineralization (data from Map 1, in pocket).

0361-0128/98/000/000-00 $6.00 1073 1074 AMES ET AL.

N

64 40 35

70 37

44 68

70

50

SIC SIC 85 its 48 depos 44 on ili 67 Zn-Pb-Cu 45 Errington-Verm 77 60

40 50

65 75

10 km

FIG. 9. Surface projections of Ni-Cu-PGE and hydrothermal Zn-Pb-Cu mineralization and representative dip measure- ments of the base of the Sudbury Igneous Complex shown at 10-km intervals (data from CVRD-Inco, FNX Mining Ltd., Xstrata Ltd.) based on data from FNX Mining Company Inc., Vale-INCO slabs, and photomicrographs of ore textures of the Ni-Cu- Ltd, and Xstrata Nickel (Fig. 9). Several past producers of PGE mineralization are shown for the various ore environ- gold, copper, and uranium also occur in the region, although ments (Ames, 2007a). they are temporally unrelated to the 1.8 Ga Sudbury impact. The footwall geologic environment is least understood, About half of the total past production and current re- with deposit models evolving as new styles of economic min- sources of Ni, Cu, and PGE is associated with the basal con- eralization are found in the mining camp. Cu-rich deposits tact of the Sudbury Igneous Complex; ~25 percent occurs in hosted in the Sudbury Igneous Complex footwall environ- the offset environment and ~25 percent in the footwall envi- ment have significant precious metal contents, typically >6 g/t ronment, all in breccias proximal to the base of the Sudbury Pt + Pd + Au + Ag (i.e., Strathcona deep copper: Abel et al., Igneous Complex (Fig. 7). Significant host rocks for Ni-Cu- 1979; Farrow and Lightfoot, 2002). Low-sulfide, high PGE- PGE mineralization in Sudbury include footwall breccia (unit Au, Ag deposits represent a recently recognized style of min- 35) and sublayer (unit 40) in the basal contact environment of eralization in the district and are a potential future source of the Sudbury Igneous Complex; inclusion-rich “quartz diorite” significant PGE-Au production. The first economic deposit (unit 36) in the offset environment, and Sudbury breccia (unit mined of this type was at the McCreedy West deposit, PM 34) that developed in a variety of Neoarchean and Paleopro- zone, mined in 2005 (Farrow et al., 2005), which had typical terozoic rocks in the stratigraphic footwall of the Sudbury grades of 0.3 percent Ni, 1.0 percent Cu, >5 g/t (Pd + Pt + Igneous Complex. Photographs of outcrops, polished rock Au) and low sulfide content (<3 wt % S). The disseminated

0361-0128/98/000/000-00 $6.00 1074 GEOLOGY OF THE GIANT SUDBURY MINING CAMP, ONTARIO, CANADA 1075 sulfides with elevated precious metal contents are hosted in Canada: A synthesis of major deposit-types, district metallogeny, the evolu- strongly brecciated, pseudotachylitic footwall rocks (Sudbury tion of geological provinces, and exploration methods: Geological Associa- tion of Canada, Mineral Deposits Division, Special Publication no. 5, Ore Breccias, unit 34). Current exploration for this type of ore is Photo library on DVD, 35 figures. extensive in the vicinity of known Ni-Cu mines. Low-sulfide, Ames, D.E. and Farrow, C.E.G., 2007, Metallogeny of the Sudbury min- high-PGE mineralization is also recognized at the Levack ing camp, Ontario, in Goodfellow W.D., ed., Mineral deposits of Canada: mine (north 148 zone), Levack Footwall, Victor, Capre (3000 A synthesis of major deposit-types, district metallogeny, the evolution of zone), Ni Rim South, Broken Hammer, Crean Hill, and Lit- geological provinces, and exploration methods: Geological Association of Canada, Mineral Deposits Division, Special Publication no. 5, p. tle Stobie. 329–350. The 6.4 Mt Errington-Vermilion Zn-Pb-Cu deposits (Ames Ames, D.E., and Gibson, H.L., 2004a, Geology, alteration and mineralization et al., 2006; Ames, 2007b) occur in the Whitewater Group, of the Onaping Formation, Morgan Township, Sudbury structure, Ontario: stratigraphically ~1.5 to 2 km above the Sudbury Igneous Geological Survey of Canada Open File 3717, 2 map sheets with descrip- tive notes, 8 figures, scale 1:5000. Complex. These base metal deposits have regional semicon- ——2004b, Geology, alteration and mineralization of the Onaping Forma- formable alteration zones in the footwall that were dated at tion, Rockcut Lake area, Norman Township, Sudbury, Ontario: Geological 1848.4 ±1 Ma (modified from Ames et al., 1998; see Table 2). Survey of Canada Open File 4565, 1 sheet with 4 figures and 1 table, scale Heat from the Sudbury Igneous Complex caused hydrother- 1:2000. mal convection above the melt sheet. VMS-like Zn-Pb-Cu de- ——2004c, Geology, alteration and mineralization of the Onaping Forma- tion, Joe Lake area, Wisner Township, Sudbury, Ontario:Geological Survey posits formed in the crater fill above the Sudbury Igneous of Canada Open File 4566, 1 sheet, 5 figures and 1 table, scale 1:2000. Complex, and the Ni-Cu-PGE deposits below the complex ——2004d, Geology, alteration and mineralization of the Onaping Forma- were modified by hydrothermal activity (fig. 11 in Ames et al., tion, Simmons Lake area, Dowling Township, Sudbury, Ontario: Geologi- 2006). cal Survey of Canada Open File 4567, 1 sheet with 4 figures and 1 table, scale 1:2000. The new compilation map of the Sudbury district provided ——2004e, Geology, alteration and mineralization of the Onaping Forma- in this issue integrates the geology, geochronology, impact tion, Cow Lake area, Dowling Township, Sudbury, Ontario: Geological Sur- features, and metallogeny across 9 NTS (National Topo- vey of Canada Open File 4568, 1 color sheet with 7 figures and 1 table, graphic System) sheets, covering about 80 × 60 km, and pro- scale 1:2000. vides the most up-to-date tectonostratigraphic framework Ames, D.E., Watkinson, D.H., and Parrish, R.R., 1998, Dating of a regional hydrothermal system induced by the 1850 Ma Sudbury impact event: Ge- for resource exploration and development, education, and ology, v. 26, p. 447–450. research. Ames, D.E, Golightly, J.P., Lightfoot, P.C. and Gibson, H.L., 2002, Vitric compositions in the Onaping Formation and their relationship to the Sud- Acknowledgments bury Igneous Complex, Sudbury structure: ECONOMIC GEOLOGY, v. 97, p. Discussions with numerous Sudbury explorationists and 1541–1562. Ames, D.E., Kjarsgaard, I.M. and Douma, S.L., 2003, Sudbury Ni-Cu-PGE academic and government geologists have been invaluable. ore mineralogy compilation: Sudbury targeted geoscience initiative, Geo- Particularly, Ken Card, Catharine Farrow, Harold Gibson, logical Survey of Canada Open File 1787, CD-ROM. Paul Golightly, Peter Lightfoot, Gordon Morrison, and Ed- Ames, D.E., Buckle, J., Davidson, A., and Card, K., 2005, Sudbury bedrock ward Pattison have openly provided insights into the intrigu- compilation: Geological Survey of Canada Open File 4570, geology, color map, and digital tables, scale 1:50,000. ing world of Sudbury geology and the development of one of Ames, D.E., Jonasson, I.R., Gibson, H.L., Pope, K.O., 2006, Impact-gener- the world’s premier polymetallic mining camps. Constructive ated hydrothermal system—constraints from the large Paleoproterozoic comments and reviews by Wouter Bleeker, Michael Easton, Sudbury crater, Canada, in Cockell, C., Gilmour, I., Koeberl, C., eds., Bio- and John Spray are gratefully acknowledged. We thank John logical processes associated with impact events, Impact Studies, Berlin, Buckle, Darren Viner, and Beth Hillary for GIS development Springer-Verlag, p. 55–100. Bailey, J., LaFrance, B., McDonald, A.M., Fedorowich, J.S., Kamo, S., and of the Sudbury map. This is GSC contribution number Archibald, D.A., 2004, Mazatzal-Labradorian-age (1.7-1.6 Ga) ductile de- 20080189. formation of the South Range Sudbury impact structure at the Thayer Lindsley mine, Ontario: Canadian Journal of Earth Science, v. 41, p. January 14, July 16, 2008 1491–1505. 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Cannon, W.F. and Addison, W.D., 2007, The Sudbury impact layer in the in Goodfellow W.D., ed., Mineral deposits of Canada: A synthesis of major Lake Superior Iron Ranges: A time-line from the heavens: Institute on deposit-types, district metallogeny, the evolution of geological provinces, Lake Superior Geology, Proceedings, v. 53, p. 20–21. and exploration methods: Geological Association of Canada, Mineral De- Card, K.D., 1965, Geology of Hyman and Drury Townships: Ontario De- posits Division, Special Publication no. 5, Ore Photo library on DVD, 111 partment of Mines, Geological Report no. 34. figures. ——1968, Geology of Denison-Waters Area: Ontario Department of Mines, ——2007b: Whitewater Group impact-generated massive sulphide deposits, Geological Report no. 60, 63 p. Sudbury district, Ontario, in Goodfellow W.D., ed., Mineral deposits of ——1969, Map 2170, Sudbury Mining Area, (O.D.M.) scale 1 inch to 1 mile.

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