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IntroductionA NEW, 1:100,000 SCALE compilation bedrock geology mapprovided with this issue presents a geologic synthesis ofCanada’s most prolific mining camp, the world-class Sudburystructure with total past production and current reserves ofover 1.7 billion tonnes of Ni, Cu, Co, Pt, Pd, Au, Ag ore(Lydon, 2007). The polymetallic ore is hosted within one ofEarth’s largest preserved impact craters. The new map of theNi-Cu-PGE Sudbury district (after Ames et al., 2005) is in-cluded in a pocket at the back of this issue (Map 1) and islinked to mineral deposit-commodity and geochronology datain Tables 1 and 2 of this paper.

Since 1891, six compilation maps of the geology of Sudburyhave been published (Bell, 1891; Collins, 1937; Cooke, 1946;Card, 1969; Dressler, 1984; Ames et al., 2005) (Fig. 1). Someof the Ni-Cu-PGE mines have operated for over a century,whereas new ore deposits, discovered as recently as 2004, arealready in production or are in the process of being developed(i.e., advanced prospects). In the last 15 years, Sudbury hasbeen the training ground for ~60 postgraduate geosciencestudents in North America (Fig. 1). From 1903 to 1990, only23 graduate theses were completed on Sudbury-related top-ics; eight of them in the 1970s, after the discovery of shattercones (Dietz, 1964).

Map 1 presents new information on (1) the impactites(Stöffler and Grieve, 2007) of the Sudbury impact crater(units 34–46), which include the Sudbury Igneous Complexand related radial and concentric offset dikes, the impactcrater infill breccia dikes, the impact crater infill of the On-aping Formation, pseudotachylite and other impact featuressuch as shatter cones, (2) the Neoarchean Levack gneiss com-plex in the northern footwall, and (3) the Grenville Frontarea. The explicit interpretation of the origin of the igneouscomplex as a differentiated melt sheet in the Sudbury impactstructure, overlain by and assimilating its own fallback brec-cias (Grieve et al., 1991), is now widely accepted as a generalframework. New data on these features, described in moredetail below, are integrated with a compilation of U-Pbgeochronology, mineral deposits, and occurrences (includingsurface projections of mineralization and recent discoveries),and previous bedrock mapping. This compilation map con-tributes to our understanding of one of the world’s geologicfeatures of extraordinary economic and scientific importance.

Geologic Setting

Sudbury structure

The bolide that impacted the continental margin of Nuna,Earth’s first supercontinent, produced the ~200 km, 1850 MaSudbury impact crater. The Sudbury structure, a deformedremnant of an impact basin, straddles the boundary betweenNeoarchean tonalitic Levack gneiss and Paleoproterozoicmetavolcanic and metasedimentary Huronian Supergroupstrata, and related granitic rocks (Fig. 2). The most prominentfeature of the eroded remnant of the original, much more ex-tensive multi-ring impact basin (Spray et al., 2004) is theSudbury Igneous Complex, which is interpreted as a meltsheet and includes the 60 × 30 km deformed outline of theSudbury Igneous Complex and associated radial and concen-tric offset dikes (Map 1, units 36–40) (Grieve et al., 1991;Lightfoot et al., 1997). The impact model for the Sudburystructure has been widely accepted since its inception over40 years ago following the recognition of shatter cones(Dietz, 1964). The shatter cones, which form a 10-km-widehalo around the Sudbury Igneous Complex, generally point

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

† Corresponding author: e-mail, dames@NRCan.gc.ca

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

Num

ber

ofgr

adua

teth

eses

Decade

25

30

35

20

15

10

5

0 1900

1890

1910

1920

1930

1940

1950

196 0

197 0

1980

1990

2000

2007

Discovery ofshatterconesDiscovery ofshattercones

Discovery ofIr anomaly

Discovery ofIr anomaly

Irdistal

IrdistalIr

proximalIr

proximal

Col

lins

Bel

l

Coo

ke

Car

d

Dre

ssle

r

Am

eset

al.

* **

FIG. 1. Number of graduate theses of North American geoscientiststrained on Sudbury geology per decade, showing the minor peak in trainingafter the discovery of shatter cones and the recent “education boom,” withover 50 geoscience graduate theses completed since 1990. The dashed linesrepresent the regional geologic maps of the Sudbury area produced over thehistory of the Sudbury mining camp.

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

Location no. Name Commodity Source of data

NTS Sheet 041I051 Kordal no. 2 Ni, Cu, Co Ontario Mineral Deposit Inventory2 Kordol main zone Ni, Cu, Co, Pd Ontario Mineral Deposit Inventory3 Kordal no. 3 Ni, Cu, Co Ontario Mineral Deposit Inventory4 Pond, Gaele Pond West Ni, Cu Ontario Mineral Deposit Inventory5 Kordal no. 4 zone Ni, Cu, Co Ontario Mineral Deposit Inventory6 Trill Offset Ni, Cu, PGE Wallbridge Inc7 Lot 12, Con 4, Tamminen, T, Pond showing no. 2 Cu Ontario Mineral Deposit Inventory8 Lot 11, Con 3 Cu Ontario Mineral Deposit Inventory9 Agnew Lake mine U, Cu, Th Dressler, 1984

10 Ni, Cu Dressler, 198411 Lot 10, Con 2 Cu Ontario Mineral Deposit Inventory12 Ministic Creek, Lot 10, Con 4, Alford Ni, Cu Ontario Mineral Deposit Inventory13 Trillabelle Ni, Cu Dressler, 198414 U Dressler, 198415 Ryanor, Alanen And Maki Cu Ontario Mineral Deposit Inventory16 Lot 8, Con 3 Ni, Cu Ontario Mineral Deposit Inventory17 Sultana Ni, Cu Dressler, 198418 Robb Farm, Se 1/4, S1/2 Lot 7, Con 1 Ni, Cu Ontario Mineral Deposit Inventory19 Garrison Harbour, Dwyer U. Cu Ontario Mineral Deposit Inventory

NTS Sheet 041I061 Alanen And Maki U, Cu, Th Ontario Mineral Deposit Inventory2 Dwyer Au, Ag Ontario Mineral Deposit Inventory3 Lot 6, Con 4 Cu Cu Ontario Mineral Deposit Inventory4 Lot 5, Con 2 Cu Ontario Mineral Deposit Inventory5 Lot 6, Con 3 Ni, Cu Ontario Mineral Deposit Inventory6 Sudbury Lode Mines Cu, Au, Pb, Zn Ontario Mineral Deposit Inventory7 Grimsell, Paramaque Ni, Cu Ontario Mineral Deposit Inventory8 Lot 5, Con 3, Grimsell 2, Paramaque 2 Ni, Cu Ontario Mineral Deposit Inventory9 Lot 4, Con 4 North Ni, Cu Ontario Mineral Deposit Inventory

10 Lot 4, Con 4 South Ni, Cu Ontario Mineral Deposit Inventory11 Ni, S Dressler, 198412 Chicago mine Ni, Cu Dressler, 198413 Worthington Mines prospect Ni, Cu Ontario Mineral Deposit Inventory14 Loughrim & Dwyer prospect Ni, Cu Ontario Mineral Deposit Inventory15 Totten Ni, Cu, PGE Ames et al., 200316 Ni, S Dressler, 198417 Ni, Cu Dressler, 198418 Worthington mine Ni, Cu Dressler, 198419 Tamminen Ni, Cu Ontario Mineral Deposit Inventory20 Ni, Cu Dressler, 198421 Ni, S Dressler, 198422 Ni, S Dressler, 198423 Boundary Ni, Cu Ontario Mineral Deposit Inventory24 Howland pit Ni, Cu Card, 196825 AER Ni, Cu Ames et al., 200326 Ni, Cu Dressler, 198427 Pilspanen, V Ni Ontario Mineral Deposit Inventory28 Kidd Copper Ni, Cu, PGE Dressler, 198429 Ni, S Dressler, 198430 Ni, Cu Dressler, 198431 Lot 11, Con 2 Cu Ontario Mineral Deposit Inventory32 Ni, S Dressler, 198433 McIntyre mine/Gersdorffite Ni, Cu Dressler, 198434 Ni, S Dressler, 198435 Ni, Cu Dressler, 198436 Ni, Cu Dressler, 198437 Ni, Cu Dressler, 198438 Victoria mine Ni, Cu, PGE Ames et al., 200339 Ethel Lake Cu Ontario Mineral Deposit Inventory40 Ni, Cu Dressler, 198441 Lots 6,7,8, Con 3, Denison Tp Cu Ontario Mineral Deposit Inventory42 Vermilion mine Ni, Cu, PGE Dressler, 198443 Ni, Cu Dressler, 198444 Crean Hill mine Ni, Cu Dressler, 198445 Lots 3 and 4, Con 4 Cu Ontario Mineral Deposit Inventory46 Lots 3 and 4, Con 5 Cu Ontario Mineral Deposit Inventory47 Ni, Cu Dressler, 1984

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48 Lockerby mine Ni, Cu, PGE Dressler, 198449 Ellen pit Ni, Cu Dressler, 198450 Ranger, Henry Au, Cu, Pb Ontario Mineral Deposit Inventory51 Vermilion River Mo Ontario Mineral Deposit Inventory52 McVittie-Graham Ni, Cu, PGE Dressler, 198453 Lot 12, Con 3, Graham Copper-Lot 12 Cu Ontario Mineral Deposit Inventory54 Simpson Au, Ag, Cu, PGE Ontario Mineral Deposit Inventory55 Lots 9,10,11, Con 4 Cu Ontario Mineral Deposit Inventory56 Lot 9, Con 3 Cu Ontario Mineral Deposit Inventory57 Lot 8, Con 4 Cu Ontario Mineral Deposit Inventory58 Lot 7,8, Con 3 Ni, Cu Ontario Mineral Deposit Inventory59 Lots 6,7,8, Con 3 Cu Ontario Mineral Deposit Inventory60 Nemag Lake Cobalt Co Ontario Mineral Deposit Inventory61 Russell Property, Lot 6 Con 3 Cu, Co Ontario Mineral Deposit Inventory62 Lot 6, Con 3 Pb, As, Co, Cu Ontario Mineral Deposit Inventory63 Lots 5,6 Con 3 Ni, Cu Ontario Mineral Deposit Inventory64 Ni, Cu Dressler, 198465 Gertrude mine Ni, Cu Dressler, 198466 Century mine Ni, Co, Cu Ontario Mineral Deposit Inventory67 Ni, Cu Dressler, 198468 Lots 1,2,3, Con 4 Cu Ontario Mineral Deposit Inventory69 Lot 2, Con 4 Ni Ontario Mineral Deposit Inventory70 Creighton mine Ni, Cu, PGE Dressler, 198471 Waters sulfide F Cu Ontario Mineral Deposit Inventory72 Waters sulfide E Cu Ontario Mineral Deposit Inventory73 Waters sulfide I Cu Ontario Mineral Deposit Inventory74 Waters sulfide H Cu Ontario Mineral Deposit Inventory75 Waters sulfide G Cu Ontario Mineral Deposit Inventory76 North Star mine Ni, Cu Ames et al., 200377 Waters Tp Cu Ontario Mineral Deposit Inventory78 J. Rauhala Ni, Cu Ontario Mineral Deposit Inventory79 Kettyle,C.J. Au Ontario Mineral Deposit Inventory80 Tam O’Shanter Ni, Cu Dressler, 198481 Campbell, P.C. Au, Ag, Pb Ontario Mineral Deposit Inventory82 Babcock, J Ni, Cu Ontario Mineral Deposit Inventory83 Mccormack, R. Au, Ag Ontario Mineral Deposit Inventory84 Fielding property W Ontario Mineral Deposit Inventory85 Copper Cliff South mine Ni, Cu Dressler, 198486 Copper Cliff no. 1 mine Ni, Cu Dressler, 198487 Evans mine Ni, Cu Dressler, 198488 Clarabelle pit Ni, Cu Dressler, 198489 Copper Cliff mine Ni, Cu Dressler, 198490 Copper Cliff North Ni, Cu, PGE Ames et al., 200391 Kelly Lake Ni, Cu, PGE Ames et al., 200392 Copper Cliff no. 2 mine Ni, Cu Dressler, 198493 Mckim L occurrence Ni, Cu Ontario Mineral Deposit Inventory94 Mckim M occurrence Ni, Cu Ontario Mineral Deposit Inventory95 Mckim J showing Ni, Cu Ontario Mineral Deposit Inventory96 Meito-Laasko Cu, Ni, Ag Ontario Mineral Deposit Inventory97 Ramsey Lake, Ennis Cu, Ni, Au Ontario Mineral Deposit Inventory

NTS Sheet 041I071 Mckim H showing Ni, Cu Ontario Mineral Deposit Inventory2 Mckim I showing Ni Ontario Mineral Deposit Inventory3 Kingsway showing Cu Ontario Mineral Deposit Inventory4 Broder Ne Ni, Cu Ontario Mineral Deposit Inventory5 Minnow Lake West pit Ni Ontario Mineral Deposit Inventory6 Mccormick, Mccormicks mine (Misnomer) Ni, Cu Ontario Mineral Deposit Inventory7 Arcadia South showing Ni, Cu Ontario Mineral Deposit Inventory8 Arcadia, Amax Neelon, Arcadia Nickel Corp Ni, Cu Ontario Mineral Deposit Inventory9 Wanapitei Complex Neelon Ni, Cu Ontario Mineral Deposit Inventory

10 Pershland South Ni, Cu Ontario Mineral Deposit Inventory11 Ni, Cu Dressler, 198412 kyanite Dressler, 198413 kyanite Dressler, 1984

NTS Sheet 041I101 Mt Nickel mine Ni, Cu Ames et al., 20032 Stobie mine Ni, Cu, PGE Ames et al., 2003

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

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3 Lindsley mine Ni, Cu, PGE Ames et al., 20034 Cu, Zn Gibbins et al., 20045 Blezard mine Ni, Cu Dressler, 19846 Papineau Au, Ag, Cu, Pb Ontario Mineral Deposit Inventory7 Microwave showing Ni, Cu Ontario Mineral Deposit Inventory8 Lasalle Cu, Ni, Ag, Au Ontario Mineral Deposit Inventory9 Pyrite Gibbins et al., 2004

10 Hanmer, Sudbury Basin Mines Cu, Pb, Zn Ontario Mineral Deposit Inventory11 Jenkins, H. (Placer), Vermilion Valle Au Ontario Mineral Deposit Inventory12 Sheppard, Shepherd, Davis Ni, Cu Ontario Mineral Deposit Inventory13 Sheppard property Ni, Cu Dressler, 198414 Sir Mortimer Davis, Track-Davis Ni, Cu, PGE Ontario Mineral Deposit Inventory15 Kenn Holdings And Mining Cu, Ni Ontario Mineral Deposit Inventory16 Neelon township NW Ni Ontario Mineral Deposit Inventory17 West Bay Ni, Cu Ontario Mineral Deposit Inventory18 Onwatin placer, Capreol township plac Au Ontario Mineral Deposit Inventory19 Malbeuf and Martin Ni, Cu Ontario Mineral Deposit Inventory20 Pyrite Gibbins et al., 200421 Zn Gibbins et al., 200422 Kirkwood FW showing Cu, Ni, PGE23 Segway Cu, Ni, PGE FNX Mining Inc24 Kirkwood mine Ni, Cu Dressler, 198425 Leclerk Ni, Cu Ontario Mineral Deposit Inventory26 Ni, Cu Dressler, 198427 Quartz Gibbins et al., 200428 McConnell offset Ni, Cu Ames et al., 200329 Executive Neelon Cu, Ag Ontario Mineral Deposit Inventory30 Waddell Lake, Cleveland Copper Corp. Ni, Cu Ontario Mineral Deposit Inventory31 Garson mine Ni, Cu, PGE Dressler, 198432 Cu Gibbins et al., 200433 Zn, Cu, Pb Gibbins et al., 200434 West Bay roadside Cu, Ni Ontario Mineral Deposit Inventory35 Q, Pd, Pt Gibbins et al., 200436 Zn, Pb Gibbins et al., 200437 Ni, Cu Dressler, 198438 Amy Lake showing no. 1 Cu, Ni, PGE Wallbridge Inc39 Amy Lake showing no. 2 Cu, Ni, PGE Wallbridge Inc40 Capre property Ni, Cu Dressler, 198441 Ni, Cu Dressler, 198442 Victor Main/Deep Ni, Cu, PGE Ames et al., 200343 Nickel Rim depth Ni, Cu, PGE Ames et al., 200344 Victor mine Ni, Cu Ames et al., 200345 Nickel Rim mine Ni, Cu, PGE Dressler, 198446 Falconbridge mine Ni, Cu, PGE Dressler, 198447 Nickel Rim South Ni, Cu, PGE Ames et al., 200348 Falconbridge East mine Ni, Cu Dressler, 198449 U Dressler, 198450 MacLennan mine Ni, Cu, PGE Dressler, 198451 Cryderman property Ni, Cu Dressler, 198452 Massey Bay U Ontario Mineral Deposit Inventory53 U Dressler, 198454 Ni, Cu Dressler, 198455 Norduna mine Ni, Cu Dressler, 198456 Pershland Ni, Cu Ontario Mineral Deposit Inventory57 Copper Prince Resources Inc. Cu, Au Dressler, 198458 Chevrette, E. U Ontario Mineral Deposit Inventory59 Cu, Zn, Ni, Au, Ag Dressler, 198460 Skead mine Au Dressler, 198461 kyanite Dressler, 198462 Cu, Zn, Ni, Au, Ag Dressler, 198463 Falcon, Beckley Au Ontario Mineral Deposit Inventory64 Hodden Grey Cu Ontario Mineral Deposit Inventory65 Wanapitei Au Ontario Mineral Deposit Inventory66 Sheppard gold mine (Misnomer) Au Ontario Mineral Deposit Inventory67 Mackenzie Au, Cu, Ni Ontario Mineral Deposit Inventory68 Manchester Ni, Cu Ames et al., 200369 Bonanza mine Au, q Dressler, 198470 Maclennan township Au Ontario Mineral Deposit Inventory71 Foisey Ni, Cu Ontario Mineral Deposit Inventory

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

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72 Midway Energy and Mines Cu, Fe, S Easton and Murphy, 200073 Street occurrence 4 Cu Easton and Murphy, 200074 Street occurrence no. 1 Cu, Fe, S Easton and Murphy, 200075 Street occurrence no. 2 Au, Cu Easton and Murphy, 200076 Prosco Mines Limited Cu, U Ontario Mineral Deposit Inventory77 West Side outlet bay Ni, Cu Ontario Mineral Deposit Inventory78 Street occurrence no. 6 Cu, Fe, S Easton and Murphy, 200079 Au Dressler, 198480 Moose Rapids Ni, Cu Ontario Mineral Deposit Inventory81 Potvin Fe, S Easton and Murphy, 200082 Scadding Au Ontario Mineral Deposit Inventory83 Au Dressler, 198484 Au, Cu Dressler, 198485 Boulanger-Potvin Au, Cu, Fe, S Easton and Murphy, 200086 Gordon Au Ontario Mineral Deposit Inventory87 Red Rock mine Au Dressler, 198488 Mid-Continental Au Ontario Mineral Deposit Inventory89 Glade Au, Cu, Ni, Ag, Co Ontario Mineral Deposit Inventory90 Au Dressler, 198491 Street occurrence no. 2a garnet, verm Easton and Murphy, 200092 Street occurrence no. 2b garnet, ky Easton and Murphy, 200093 Street occurrence no. 2c garnet Easton and Murphy, 200094 Street occurrence no. 8 Au, Cu, As Easton and Murphy, 200095 Street occurrence Cu Easton and Murphy, 2000

NTS Sheet 041I111 Pyrite Gibbins et al., 20042 Ni, Cu Dressler, 19843 Siderite Gibbins et al., 20044 Zn, Cu Gibbins et al., 20045 Zn, Cu Gibbins et al., 20046 Sudbury Elbow Cu, Pb, Zn, Ag, Au Ontario Mineral Deposit Inventory7 Canada Radium, Pacemaker Mines and Oils As Ontario Mineral Deposit Inventory8 Simmons Pb, Cu Ames and Gibson, 2004d9 Zn Gibbins et al., 2004

10 Cu Gibbins et al., 200411 Zn, Pb, Cu Gibbins et al., 200412 A & M Peperite Ames, 199913 Hardy pit Ni, Cu Dressler, 198414 Py Gibbins et al., 200415 Boundary mine Ni, Cu Dressler, 198416 Cu, Ni, Pb Dressler, 198417 Morley Zn, Pb, Cu Gibbins et al., 200418 Onaping mine Ni, Cu Ames et al., 200319 TT showing Zn Gray, 199520 Levack mine Ni, Cu Dressler, 198421 North trench Zn Gray, 199522 Dowling Ni, Cu, PGE Ames et al., 200323 Onaping depth Ni, Cu Ames et al., 200324 2 Pb, Zn, Cu Gibbins et al., 200425 Craig mine Ni, Cu Ames et al., 200326 LW showing Zn, Cu, As Gray, 199527 3 Zn, Cu, Pb Gibbins et al., 200428 Anthraxolite 1 C Dressler, 198429 McCreedy West mine Ni, Cu, PGE Ames et al., 200330 4 Zn, Cu Gibbins et al., 200431 Fecunis mine Ni, Cu Dressler, 198432 Cu Gray, 199533 Vermilion-Whitewater Zn, Pb, Cu, Au, Dressler, 198434 5 Zn, Cu Gibbins et al., 200435 North mine Ni, Cu Ames et al., 200336 Cow Lake Zn, Cu Ames and Gibson, 2004e37 McNunes Zn, Cu, Pb Ames and Gibson, 2004e38 McCreedy East mine Ni, Cu, PGE Ames et al., 200339 Strathcona mine Ni, Cu, PGE Dressler, 198440 Fraser mine Ni, Cu, PGE Ames et al., 200341 Onex shaft Ni, Cu Ontario Mineral Deposit Inventory42 10 Zn, Cu, Pb Gibbins et al., 200443 Coleman mine Ni, Cu, PGE Ames et al., 2003

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

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44 Gordon Lake Road Peperite Ames, 199945 Sturdy Mines Ltd. Zn, Pb, Cu Dressler, 198446 11 Cu, Zn, Pb Gibbins et al., 200447 12 Zn, Cu Gibbins et al., 200448 Longvack mine Ni, Cu Ames et al., 200349 Lower Coleman Ni, Cu Ames et al., 200350 Barnet Cu, Ni, PGE Ames et al., 200351 13 Zn Gibbins et al., 200452 9 Zn, Cu Gibbins et al., 200453 Pb, Ag, Cu Gibbins et al., 200454 Big Levack Ni, Cu Dressler, 198455 Fraser-Morgan Ni, Cu Ames et al., 200356 14 Zn Gibbins et al., 200457 15 Cu, Zn Gibbins et al., 200458 Sudbury midzone Cu, Pb, Zn Ontario Mineral Deposit Inventory59 Au Gibbins et al., 200460 Rudy’s Lake Cu, Fe Ontario Mineral Deposit Inventory61 Ni, Cu Dressler, 198462 Anthraxolite 2 C Dressler, 198463 16 Zn, Cu Gibbins et al., 200464 River shaft Zn, Pb, Cu, Au, Dressler, 198465 17 - Ryan Zn, Cu, Pb Gibbins et al., 200466 Errington No. 1 mine Zn, Pb, Cu, Ag Dressler, 198467 Hamilton F Cu Ontario Mineral Deposit Inventory68 18 Zn, Cu, Pb, Au Gibbins et al., 200469 Northwest Balfour Pb, Zn Ontario Mineral Deposit Inventory70 Quartz Gibbins et al., 200471 Vermilion River, lot 8, Con V Cu, Pb, Zn Ontario Mineral Deposit Inventory72 Errington no. 2 mine Zn, Pb, Cu, Ag Dressler, 198473 Balfour, lot 7, Conc VI Cu, Pb, Zn, Au Ontario Mineral Deposit Inventory74 Limerick Cu, Zn Ames and Gibson, 2004a75 Quartz Gibbins et al., 200476 Zn, Cu, Pb Gibbins et al., 200477 Irwin Zn, Pb, Cu, Au, Dressler, 198478 Tournigy Zn, Cu Paakki, 199279 20 Zn, Cu Gibbins et al., 200480 North-East Balfour Cu, Pb, Zn Ontario Mineral Deposit Inventory81 Errington no. 3 Zn, Pb, Cu, Au, Dressler, 198482 Moore Lake Pb, Zn Ontario Mineral Deposit Inventory83 WD 248 Ni, Cu Ames et al., 200384 WD 233 property Ni, Cu Dressler, 198485 Whitewater Lake Cu Ontario Mineral Deposit Inventory86 Bowell Ni, Cu Ames et al., 200387 Cu Gibbins et al., 200488 Zn Gibbins et al., 200489 Rand Creek, Foy offset Ni, Cu Ontario Mineral Deposit Inventory90 Zn, Cu Gibbins et al., 200491 WD 236 Ni, Cu Dressler, 198492 WD 212 property Ni, Cu Dressler, 198493 WD 152 Ni, Cu Ames et al., 200394 Nickel Lake Ni, Cu Ames et al., 200395 WD 237 property Ni, Cu Dressler, 198496 WD 150 Ni, Cu Dressler, 198497 WD 155 Ni, Cu Ames et al., 200398 Zn, Cu Gibbins et al., 200499 Zn, Cu Gibbins et al., 2004

100 Zn, Cu Gibbins et al., 2004101 WD 229 Ni, Cu Ames et al., 2003102 Prue, Proulx, Nelson Lake Zn, Cu Dressler, 1984103 Cu, Zn Gibbins et al., 2004104 WD 209 Ni, Cu Dressler, 1984105 Lady Violet mine Ni, Cu Ontario Mineral Deposit Inventory106 Foisey Cu, Pb, Zn Ontario Mineral Deposit Inventory107 Cu, Zn Gibbins et al., 2004108 Elsie Ni, Cu Ontario Mineral Deposit Inventory109 Murray mine Ni, Cu Dressler, 1984110 Discovery site Ni, Cu Ontario Mineral Deposit Inventory111 McKim mine Ni, Cu Ames et al., 2003112 North Range shaft Ni, Cu Dressler, 1984

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

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113 Ni, Cu Dressler, 1984114 Ni, Cu Dressler, 1984115 Zn, Cu Gibbins et al., 2004116 Zn Gibbins et al., 2004117 Ni, Cu Dressler, 1984118 Blezard Lot 8, Con Ii Ni, Cu Ontario Mineral Deposit Inventory119 Zn, Pb, Cu Gibbins et al., 2004120 Junior Frood Ni, Cu Ontario Mineral Deposit Inventory121 Cameron mine (misnomer) Ni Ontario Mineral Deposit Inventory122 Blezard-Val Caron Cu, Pb, Zn Ontario Mineral Deposit Inventory123 Little Stobie mine Ni, Cu, PGE Ames et al., 2003124 Frood mine Ni, Cu, PGE Ames et al., 2003125 Zn, Cu, Pb Gibbins et al., 2004

NTS Sheet 041I121 Moore And Johns Cu Ontario Mineral Deposit Inventory2 Balboa, Pumphouse Creek, Balboa Uranium Mines Th, U Ontario Mineral Deposit Inventory3 Alcourt Mines U Ontario Mineral Deposit Inventory4 Dumont Cu Ontario Mineral Deposit Inventory5 Mousseau Lake Zn Ontario Mineral Deposit Inventory6 Fe, Cu Dressler, 19847 Camp Ten Lake Cu Ontario Mineral Deposit Inventory8 Benson Lake Magnetite Mt Ontario Mineral Deposit Inventory9 Trill Deep Ni, Cu Ames et al., 2003

NTS Sheet 041I131 Moncrieff sulfide no. 11 Ni Ontario Mineral Deposit Inventory2 Moncrieff Tp sulfide Ni Ontario Mineral Deposit Inventory3 Moncrieff Creek Mo, Cu. Pb, Zn Ontario Mineral Deposit Inventory4 Tracanelli Co, Ni, Au, Bi, Cu Ontario Mineral Deposit Inventory5 Hollinger U Ontario Mineral Deposit Inventory6 Munster sulfide Cu, Ni Ontario Mineral Deposit Inventory7 Moncrieff sulfide no. 7 Ni Ontario Mineral Deposit Inventory8 Munster drilled sulfide Ni Ontario Mineral Deposit Inventory9 North West Hess township sulfide Magnetite Ontario Mineral Deposit Inventory

10 Munster township Magnetite Ontario Mineral Deposit Inventory11 Geneva Lake mine Zn, Pb, Ag, Au Dressler, 198412 Central Hess township Au Ontario Mineral Deposit Inventory13 Zn, Pb, Cu, Ag Dressler, 198414 Fe Dressler, 198415 Geneva Lake prospect As, Pb, Ba Ontario Mineral Deposit Inventory

NTS Sheet 041I141 Eams Cu Ontario Mineral Deposit Inventory2 Ni, Cu Dressler, 19843 Harty township Cu Ontario Mineral Deposit Inventory4 Cartier regional Ni, Cu Ontario Mineral Deposit Inventory5 South Lake, Botha, Sandfly Lake Cu Ontario Mineral Deposit Inventory6 Ni, Cu Dressler, 19847 Sandcherry Lake Ni, Cu Ontario Mineral Deposit Inventory8 Ni, Cu Dressler, 19849 Holmstrom, Venetian Lake Ag, Cu, Pb, Zn, Au Ontario Mineral Deposit Inventory

10 Nickel offset mine Ni, Cu, PGE Dressler, 198411 WD 250 Ni, Cu Ames et al., 200312 Mcgrindle Lake, Botha, Mccrindle Cu Ontario Mineral Deposit Inventory13 WD 234 Ni, Cu Ames et al., 200314 Crazy Creek Ni, Cu Ames et al., 200315 WD 228 Ni, Cu Dressler, 198416 Copenhagen mine Cu, Pb, Ni Dressler, 198417 WD 13 Ni, Cu Ames et al., 200318 South zone Cu, Ni, PGE Wallbridge Inc19 Broken Hammer zone Cu, Ni, PGE Wallbridge Inc20 WD 16 Ni, Cu Dressler, 1984

NTS Sheet 041I151 Vermilion River Au Dressler, 19842 Au Dressler, 19843 Vermillion Placer Gold, Milnet area placer gold Au Ontario Mineral Deposit Inventory4 Concor-Chibougamau, Milnet area placer gold Au Ontario Mineral Deposit Inventory

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

towards it; the orientation of the axes cones displayed on Map1 plunge both upward and downward. The recent discoveryof the iridium anomaly in the upper 800 m of crater-fill brec-cias (Dowling member of the Onaping Formation: Mungall etal., 2004; Ames et al., 2005) and the recognition of out-of-crater distal ejecta in Ontario, Michigan, and Minnesota (Ad-dison et al., 2005; Pufahl et al., 2007) further support the im-pact origin of the Sudbury structure (Figs. 3, 4). Iridiumanomalies in the proximal ejecta of the Onaping Formation inthe Whitewater Group (Mungall et al., 2004; Ames et al.,2005; Ames and Farrow, 2007) and distal ejecta of the BaragaGroup (Pufahl et al., 2007) define a distinct timeline at 1850Ma across the midcontinent Paleoproterozoic region.

The compilation and integration of over 80 U-Pb dates(Table 2, Map 1, Figs. 5, 6), which include the age distribu-tion of major depositional, intrusive, tectonometamorphic,hydrothermal, and multiple meteorite impact events, spanthe range from Neoarchean through to Neogene. Recent ad-vances in U-Pb zircon dating, involving submillion-year ageresolution (Davis, 2008), provide unprecedented constraintson the cooling history of the noritic phase of the Sudbury

Igneous Complex impact melt, a lower crustal melt that crys-tallized between 1849.53 ± 0.21 and 1849.11 ± 0.19 Ma(Table 2). This highly precise dating provides an innovativetool for constraining metallogenic events to less than 1 m.y.Understanding the pre-, syn- (ca. 1850 Ma) and post-impacttiming of these events is crucial for effective mineral explo-ration in the Sudbury region. For example, among theyoungest post-impact events to have affected the Sudbury Ni-Cu-PGE orebodies was the intrusion of the 590 Ma Grenvillediabase dike swarm which locally remobilized sulfide ores andcut the orebodies at the Clarabelle open pit, Copper Cliff off-set, Strathcona mine, and Levack Embayment. This magma-tism was associated with Cambro-Ordovician extension alongthe Ottawa-Bonnechere graben (Fedorowich et al., 2006). At13 to 5 Ma, Tertiary brines also locally remobilized the Sud-bury sulfide ores, producing galena-sphalerite–bearing veinsat the McCreedy and Lindsley mines (Marshall et al., 1999).

The Sudbury structure comprises shocked and brecciatedfootwall rocks, the igneous rocks of the Sudbury IgneousComplex and offset dikes, and breccias of the Onaping For-mation. The salient stratigraphic components are illustrated

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5 Harold Barry dike Cu Ontario Mineral Deposit Inventory6 Ni, Cu Dressler, 19847 Zn, Cu, Ni Dressler, 19848 Ni, Cu Dressler, 19849 Brown Gold Au, Ag, Pb Ontario Mineral Deposit Inventory

10 Ni, Cu Dressler, 198411 Norman West Ni, Cu Ames et al., 200312 Se Island Lk Cu Ontario Mineral Deposit Inventory13 New Dominion Ni, Cu Ontario Mineral Deposit Inventory14 Golden Pine property Au, Ni Ontario Mineral Deposit Inventory15 Aro, George, Leschishin property Ag, Au Ontario Mineral Deposit Inventory16 Norpick Gold Mines N Shore Au Ontario Mineral Deposit Inventory17 Whistle mine Ni, Cu Dressler, 198418 Ni, Cu Dressler, 198419 Ni, Cu Dressler, 198420 Parkin marble Marble Ontario Mineral Deposit Inventory21 Lot 6 Con 2 Parkin, Miron, T. Ag, Au, Cu, Pb Ontario Mineral Deposit Inventory22 Decade, Mowat Creek Ag, Au, Pb, Cu, Zn Ontario Mineral Deposit Inventory23 Parkin, J. Mataris, Mowat Creek Au Ontario Mineral Deposit Inventory24 Ni, Cu Dressler, 198425 Ni, Cu Dressler, 198426 Pt, Ag, Au Dressler, 198427 Podolsky mine (Norman ) Cu, Ni, PGE Ames et al., 200328 Falmac zinc Zn, Cu Ontario Mineral Deposit Inventory29 Milnet (Jonsmith) Ni, Cu, PGE Ames et al., 200330 W.G. Peacock, R.M. Elliot, Brady,J. Au, Cu, Ni, Ag, Co Ontario Mineral Deposit Inventory31 Post Creek Cu Ontario Mineral Deposit Inventory32 Lot 4 Con 2 Parkin Au Ontario Mineral Deposit Inventory33 Free Gold, Mataris, J. Au Ontario Mineral Deposit Inventory34 Ironco Iron & Smelting Cu Ontario Mineral Deposit Inventory35 Mataris, J, Brady, J. Au Ontario Mineral Deposit Inventory36 J. Mataris lot 1, Con 1 As Ontario Mineral Deposit Inventory37 Rathbun township Fe Dressler, 198438 Dobson, Charles, Bennett, W.S., Bennett, G. Au Ontario Mineral Deposit Inventory39 Au Dressler, 198440 Rathbun Lake Cu, Ni, Pd, Pt, Au Dressler, 198441 Thomas Lake Au Ontario Mineral Deposit Inventory42 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

TABLE 1. (Cont.)

Location no. Name Commodity Source of data

in Figure 7. The erosional remnant of an impact basin, theSudbury Igneous Complex, and various breccias also define astructural basin of a regional periclinal fold which down-folded and thus preserved the Whitewater group in thecenter of the structural basin. The descriptions of units rep-resented on Map 1 avoid genetic or local terminology, in some

cases specific to one company, that has developed since thefirst discovery of Ni-Cu ore in 1883. Local names are indi-cated in parentheses in the legend (e.g., Sudbury IgneousComplex “norite” is a quartz monzogabbro-quartz gabbro). Aphoto library is available for the important rock types in theSudbury structure, including shatter cones, Sudbury breccia,

GEOLOGY OF THE GIANT SUDBURY MINING CAMP, ONTARIO, CANADA 1065

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GBF

Hess

Ministic

offset dykes

Foy

Pele

Copper Cliff

Trill

Worthington

Tyrone

Whistle-Parkin

Manchester

GBF

SRSZ

o

o

o

o

PCDZ

FLFSCF

MF

CFGBF

37 MaWanapitei

impactcraterSIC

Onaping Fm.

OnwatinFm.

Chelmsford Fm.

Zn-Pb-Cu

Onaping Intrusion

46 53’20”

46 21’20”

81 38’

80 37’

Undifferentiated

MESOPROTEROZOIC

GRENVILLE PROVINCE

SOUTHERN PROVINCE

SUDBURY STRUCTURE

PALEOPROTEROZOIC

HURONIAN SUPERGROUP

Quirke Lake Group

Hough Lake Group

Upper Elliot Lake Group: metasedimentary rocks

Lower Elliot Lake Group: metavolcanic rocks

Cobalt Group

Chief Lake Igneous Complex

SUPERIOR PROVINCENEOARCHEAN

Cartier Batholith

Levack Gneiss Complex

Ni-Cu-Co-Pt-Pd-Au mineralization

Sudbury igneous complex and related igneous rocks

Whitewater Group: fallback, hydroclastitic and plume collapse breccias

Whitewater Group: post-impact sediments

Nipissing diabase

Granite

East Bull Lake igneous suite

Mafic metavolcanic, metasedimentary rocks

GBF

10 km

N

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 = Murrayfault, CF = Creighton fault, SRSZ = South Range shear zone (hatched area), GBF = Grenville Front boundary fault.

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TABLE 2. U-Pb Isotope

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

1 2657 ± 5 CLA-93-065 507000 5180393 Monzodiorite LGC2 1849.1 ± 1.1 C-94-2 509086 5179520 Olivine melanorite pod in sublayer Whistle Embayment3 1848.3 ± 1.0 C-94-5 509086 5179520 Melanorite pod in sublayer Whistle Embayment4 1848.4 ± 1.4 C-94-7 509086 5179520 Metapyroxenite inclusion in sublayer Whistle Embayment5 1848.1 ± 1.8 C-94-8 509086 5179520 Sublayer norite matrix Whistle Embayment6 1848.7 ± 1.1 C-94-9 509086 5179520 Diabase Whistle Embayment7 1852 +4/-3 Foy-4 489818 5176477 Diorite (contact rock) Foy offset8 1852 +4/-3 Foy-1 490206 5176070 Diorite dike Foy offset9 1852 +4/-3 Foy-2 489774 5176473 Diorite dike Foy offset

10 1852 +4/-3 Foy-3 489437 5176737 Diorite dike Foy offset11 2635 ± 5 Lev-1 490049 5175874 Dioritic to monzonitic gneiss LGC12 2635 ± 5 Lev-2 490070 5175875 Dioritic to monzonitic gneiss LGC13 1848.4 ± 1 AV-J8 498828 5174642 Albitized Sandcherry member breccia Lower Onaping Formation14 2644 ± 3 CLA-93-027 516111 5173126 Massive granite LGC15 2646 ± 2 CLA-93-032B 513452 5172021 Diatexite mobilizate LGC16 2645 +7/-4 CLA-93-009A 515167 5168835 Granitic leucosome LGC17 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 granite19 2647 ± 2 TK82-10 463040 5165729 Pegmatoid LGC20 2668 +3/-2 CLA-93-175 462880 5165007 Granodiorite LGC21 2661 ± 2 CLA-93-167A 465734 5163376 Tonalite diatexite LGC22 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. intrusion26 ca. 2700 SPA89-08a 517730 5162135 Gabbro Falconbridge Twp. intrusion27 986 ± 30 SPA89-08a 517730 5162135 Gabbro Falconbridge Twp. intrusion28 1850.5 ± 3.0 TK82-15 470758 5161395 Granophyre SIC (North Range)29 2711 ± 7 TK82-14 470447 5160084 Granite xenolith Lower Onaping Formation30 1836 ± 14 TK82-14 470447 5160084 Granite xenolith Lower Onaping Formation31 2679 ± 16 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation32 2686 ± 2 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation33 2695 ± 3 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation34 2708 ± 8 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation35 2719 ± 4 Onaping Formation 470447 5160084 Basal breccia fluidal glass Lower Onaping Formation36 2647 ± 1 CLA-93-339 460167 5157468 Mafic gneiss LGC37 1848 ± 4 02-AV-852 500672 5157455 Aplite Dike, cutting norite SIC

38 2668 ± 5 CLA-93-336 459467 5157403 Granodiorite LGC39 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, SIC46 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 suite51 1471 ± 10 C4 524997 5153551 OPX-hornblendite East Bull Lake intrusive suite52 2468 ± 5 C4 524997 5153551 OPX-hornblendite East Bull Lake intrusive suite53 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 Supergroup57 1699 ± 3.6 Sheppard property 520934 5170771 Albitized metasedimentary rock Huronian Supergroup58 2477 ± 9 Murray granite 497422 5152998 Granite Murray pluton59 1850 ± 3 Murray granite 497422 5152998 Granite Murray pluton60 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 Formation62 2602.8 ± 3.3 AV-162B 469188 5151337 Quartz diorite lobe in peperite Upper Onaping Formation63 2616 ± 5.7 AV-162C 469188 5151337 Quartz diorite lobe in peperite Upper Onaping Formation64 2628.6 ± 3.2 AV-162D 469188 5151337 Quartz diorite lobe in peperite Upper Onaping Formation65 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, 1996Igneous age Zrn/Bdy Corfu and Lightfoot, 1996Igneous age Zrn Corfu and Lightfoot, 1996Igneous age Zrn/Bdy Corfu and Lightfoot, 1996Igneous age Zrn Corfu and Lightfoot, 1996Igneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samplesIgneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samplesIgneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samplesIgneous age Zrn/Bdy Ostermann et al., 1996 UI of discordia line defined by most concordant data from all four dike samplesIgneous age Zrn Ostermann et al., 1996 UI of discordia line defined by data from the two LGC samplesIgneous age Zrn Ostermann et al., 1996 UI of discordia line defined by data from the two LGC samplesHydrothermal event Ttn Ames et al., 1998 Recalculated age based on weighted average age of 5 titanite fractionsIgneous age Zrn N. Wodicka (unpub.)Migmatization Zrn N. Wodicka (unpub.)Migmatization Zrn N. Wodicka (unpub.)Igneous age Zrn Krogh et al., 1984Igneous age Zrn Meldrum et al., 1997Metamorphism Zrn Krogh et al., 1984Igneous 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 techniqueIgneous age Zrn Krogh et al., 1984Igneous age Zrn Krogh et al., 1982Igneous age Zrn Prevec and Baadsgaard, 2005Inheritance Zrn Prevec and Baadsgaard, 2005Episodic Pb loss Zrn Prevec and Baadsgaard, 2005Igneous age Bdy Krogh et al., 1984Igneous age Zrn Krogh et al., 1984 UI of discordia line defined by data from LGC and Onaping Formation samplesShock-induced Pb loss Zrn Krogh et al., 1984 LI of discordia line defined by data from LGC and Onaping Formation samplesXenocryst age Zrn Krogh et al., 1996Xenocryst age Zrn Krogh et al., 1996Xenocryst age Zrn Krogh et al., 1996Xenocryst age Zrn Krogh et al., 1996Xenocryst age Zrn Krogh et al., 1996Metamorphism 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 techniqueIgneous age Zrn Krogh et al., 1984Igneous age Zrn Krogh et al., 1982Igneous age Zrn B. Lafrance and

S. Kamo (unpub.)Metamorphism Ttn Bailey et al., 2004Shear zone formation Ttn Bailey et al., 2004Maximum igneous age Zrn Krogh et al., 1984 Interpreted maximum age based on age of norite cut by the granitic dikeMetamorphism Ttn Corfu and Easton, 2000Igneous age Zrn Corfu and Easton, 2000Metamorphism Ttn Corfu and Easton, 2000Cooling Ap Corfu and Easton, 2000Metamorphism? Zrn Corfu and Easton, 2000Metamorphism Zrn Corfu and Easton, 2000Igneous age Zrn Corfu and Easton, 2000Partial melting Zrn Corfu and Easton, 2000Inheritance? Zrn Corfu and Easton, 2000Deformation Zrn Corfu and Easton, 2000Hydrothermal event Mnz Schandl et al., 1994Hydrothermal event Mnz Schandl et al., 1994Igneous age Zrn Krogh et al., 1996 Previous age of 2388 +20/-13 Ma (Krogh et al., 1984) may be erroneously youngShock-induced Pb loss? Ttn Krogh et al., 1996Igneous 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., 1998Xenocryst age Zrn Ames et al., 1998Xenocryst age Zrn Ames et al., 1998 Minimum age (3.7% discordant fraction)Volcanism Zrn Krogh et al., 1984

Footwall breccia, Sudbury Igneous Complex and associatedoffset dikes, Onaping intrusion, and Onaping, Vermilion, andOnwatin Formations of the Whitewater Group (Ames,2007a).

A regional compilation of detailed mapping of the SudburyIgneous Complex (Shanks, 1991; Johns, 1996 a, b), new offsetdikes, and dip measurements along the base of the Sudbury

Igneous Complex are included on Map 1. Along the basalcontact of the Sudbury Igneous Complex representative dipmeasurements are displayed at 10-km intervals. The eco-nomic interest in the structural and stratigraphic footwall en-vironment of the Sudbury Igneous Complex has resulted inseveral significant geologic discoveries. Map 1 displays therecently identified offset dikes (Pele offset, discovered in

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66 1849.8 ± 2.0 C-94-12 494584 5148091 Quartz diorite Copper Cliff offset67 1747 +12/-6 92DM 169 513250 5145525 Granite dike Wanapitei Complex

68 1747+6/-5 SPA-89-31 515250 5144765 Norite Wanapitei Complex69 1859 ± 13 Spa-88-56a 464000 5141600 Gabbro Drury Twp. intrusion70 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 mine73 1815.9 ± 25.2 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine74 1817.7 ± 5.7 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine75 1818.8 ± 9.4 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine76 1832.2 ± 7.1 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine77 1833.8 ± 6.6 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine78 1858.7 ± 7.6 JF-95-65 473718 5168688 Diabase dike Strathcona Deep copper mine79 2333 +33/-22 Creighton granite 487501 5144302 Granite Creighton pluton80 2415 ± 5 LH98-63 485979 5141839 Porphyritic granite Creighton pluton81 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)

TABLE 2.

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

50°N

94°W 82°90° 86°

48°

46°

44°

78°

AnimikieGroup

HuronianSupergroup

LakeSuperio

r

La

keM

ich

iga

n

LakeH

uron

SUPERIOR PROVINCE

Quebec

Ontario

Michigan

On

tario

Ma

nito

ba

200 km

400 km60

0km

800

km

1000

km

0 200 km

U.S.A.U.S.A.

AnimikieGroup Marquette Range

SupergroupMarquette Range

Supergroup

CANADACANADAMinnesotaMinnesota Sudbur y

impactsite

Sudburyimpact

site

GRENVILLEPROVIN

CE

GRENVILLEPROVIN

CE

Distal ejecta site

Distal ejecta iridium site

Proximal ejecta iridium anomaly

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 regionat 1850 Ma. Known sites of the Sudbury iridium anomaly are shown in the proximal ejecta in the plume collapse breccia ofthe 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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Igneous age Zrn Corfu and Lightfoot, 1996Igneous age Zrn A. Davidson and O. van

Breemen (unpub.)Igneous age Zrn Prevec, 1992Shock-induced Pb loss? Zrn Prevec and Baadsgaard, 2005Igneous age Zrn Davidson and van Breemen,

1994Igneous age Ttn Davidson and van Breemen,

1994Igneous age Zrn Fedorowich et al., 2006 Magmatic titanite from same dike gives a similar age of 530 ± 21 MaXenocryst age Zrn Fedorowich et al., 2006Xenocryst age Zrn Fedorowich et al., 2006Xenocryst age Zrn Fedorowich et al., 2006Xenocryst age Zrn Fedorowich et al., 2006Xenocryst age Zrn Fedorowich et al., 2006Xenocryst age Zrn Fedorowich et al., 2006Igneous age Zrn Frarey et al., 1982 Age, based on unabraded multigrain zircon fractions, may be a minimumIgneous age Zrn Smith, 2002 Data show excess scatter and interpreted age may be a minimum (Smith, 2002)Igneous age Zrn Smith, 2002

(Cont.)

Interpretation Mineral Reference Comments

Offset dikes

N

10 km

Onaping Fm.

Onaping Fm.

Sudbury Igneous Complex

Impact diamonds

melt sheet

fallback and plume collapse breccias

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

Sudbury breccia: pseudotachylite post-2000, pre-1984 mapping

Shattercones

FIG. 4. Map showing the distribution of proximal Sudbury structure impact features including shocked rocks, impactbreccias, melt rocks, and iridium content of impact and post-impact rocks sampled. Parautochthonous impact breccias aredisplayed on Map 1 (units 34, 35); however, the regional distribution of Footwall breccia (unit 35 on Map 1) is not wellknown. 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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1

27

50

53 55

302

Impact

2500

2000

1500

1000

500

Sedimentation/Volcanism

Intrusive events Tectono-metamorphism

Ag

e(M

a)

3 4 5 6

7-10

13

44

46

43

17

22

28

37

6939

42

45

66

11-1214

15 1618

20 21

29

38

25 4752 58 60

80

81

79

19 36

igneous zirconmetamorphic zirconreset zirconigneous zircon/baddeleyite

hydrothermal monazitehydrothermal titanite

metamorphic titanitereset titanite

?

48

51

66

67

68

71

56

57

70

~2.22-2.21 Ga Nipissing diabase

Sudbury Igneous Complex

Wanapitei complex/Eden Lake suite

Chief Lake complex Chieflakian event

~2.47 Ga Matachewan swarm

~1.24 Ga Sudbury diabase dikes

GrenvillianOrogeny

Ottawa-Bonnecheregraben(500-600 Ma extensionand rifting)

Ottawa-Bonnecheregraben(500-600 Ma extensionand rifting)

59

Metamorphism/migmatization

Cooling/exhumation

Rifting Doming/uplift

PenokeanOrogeny

Yavapai-Mazatzal OrogenyYavapai-Mazatzal Orogeny

Shock-inducedPb loss?

Tonalite

Tonalite-granodiorite

Late plutonism

Mafic-Ultramafic(East Bull Lake)Mafic-Ultramafic(East Bull Lake)

HuronianSupergroup

WhitewaterGroup

Earlyvolcanism

Cartier granite

Leva

ckgn

eiss

com

plex

Leva

ckgn

eiss

com

plex

1850 Ma Sudburyimpact event

1850 Ma Sudburyimpact event

Hydrothermalevents

Hydrothermalevents

7272

igneous baddeleyite

Granite(Murray/Creighton)

Granite(Murray/Creighton)

Ni-Cu-PGE

Ni-Cu-PGE, Ag-Co

Cu-Pb-Zn-Ag

PGE-Cu-Ni

Cu, U

Au

Zn-Pb-Cu

Ni-Cu

?

?

?

?

Benny-Parkingreenstone belts

BlezardianOrogeny

2800

2700

2600

2400

2300

2200

1900

1800

1700

1600

13001300

1200

1100

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 shownwith 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 onfield relationships as given in the literature.

2007, and Trill offset, discovered in 2005), as well as exten-sions (Ministic, Foy, Parkin, Manchester, Copper Cliff, andWorthington) and revisions of known offset dikes (Lightfootet al., 1997; Wood and Spray, 1998; Murphy and Spray, 2002;Tuchscherer and Spray, 2002).

In the early 1990s, collaborative mapping by industry, uni-versity, and government researchers focused on the impactcrater fill (Onaping Formation) and the origin and setting ofthe 6.4 Mt Zn-Pb-Cu deposits at the top of the crater infill.This work established the regional stratigraphic subdivisionsand characterized the associated regional semiconformablealteration, structure, and hydrothermal base metal mineral-ization in the breccias of the Onaping Formation and overly-ing carbonates of the Vermilion Formation (too thin to showon Map 1). The Onaping Formation, overlies the melt sheetthat partially assimilated and melted the fallback breccia. Theandesitic impact melt intruded fallback breccia and formedhydroclastic breccia complexes in the Sandcherry member,Onaping Formation (Ames, 1999; Ames et al., 2002; Amesand Gibson, 2004a). Crater collapse and instability resultedin the formation of the embayment structures at the base ofthe Sudbury Igneous Complex during deposition of the On-aping Formation (Ames and Farrow, 2007). Gravitationalcollapse of the basement during deposition of the OnapingFormation is marked by growth faults, thickness variations indebris flows, and paleotopographic highs and lows at theupper contact of the Sandcherry member (Map 1, units 42,43). Subsequent plume collapse and reworking resulted in

deposition of the iridium-bearing units of the overlying Dowl-ing member (Mungall et al., 2004).

Levack gneiss complex, northern footwall rocks

One of the most conspicuous features of the northern foot-wall of the Sudbury impact crater is the 0.5- to 5-km-wide ar-cuate belt of upper amphibolite to granulite facies rocks ofthe Neoarchean Levack gneiss complex exposed along thenorthern rim of the Sudbury Igneous Complex, from Trilltownship to Wanapitei Lake (Map 1). Regional mapping bythe Geological Survey of Canada (Card, 1994) has shownthat this high-grade metamorphic complex comprises domi-nantly mafic to intermediate orthogneiss and mafic to felsicplutonic units, with minor migmatitic paragneiss and locallyrecognized iron formation. The orthogneiss ranges in age be-tween 2711 ± 7 and 2668 +3/–2 Ma (Krogh et al., 1984; Wod-icka, 1997; N., Wodicka, unpub. data), although Ostermann etal. (1996) report a distinctly younger age of 2635 ± 5 Ma fordioritic to monzonitic gneiss (Table 2). Mildly foliated to un-deformed intermediate to felsic plutons yield ages of 2657 ±5 and 2644 ± 3 Ma. The main phase of upper amphibolite togranulite facies metamorphism and migmatization occurredat crustal depths of 21 to 28 km (James et al., 1991) at about2647 to 2645 Ma (Table 2). This event immediately predatedemplacement of the postorogenic, 2642 ± 1 Ma Cartier gran-ite (Map 1, Fig. 5), a batholith-scale body of monzogranitic togranodioritic composition interpreted to have been derivedfrom partial melting, at least in part, of the Levack gneiss

GEOLOGY OF THE GIANT SUDBURY MINING CAMP, ONTARIO, CANADA 1071

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10 km

N

SOUTH RANGE SHEAR ZONE

8, 97

2-6

1

71 70

69

6867

66

81

79

80

65

61-64 60

58, 59

56

57

53-5546-4950-52

45

39, 40

41-44

3837

36

29-35

28 25-27242322

2120

19

1817

72-78

16

1514

131211

10

FIG. 6. Location of U-Pb geochronology sample sites in the Sudbury area as shown on Map 1. For legend refer to Figure2. See Table 2 for details of the age data.

complex (Meldrum et al., 1997). The field characteristics andage of the youngest plutonic rocks within the Levack gneisscomplex, particularly those of the 2644 ± 3 Ma massive gran-ite (Table 2), suggest that these rocks may represent phases ofthis batholith.

A long-standing question regarding the surface exposuredistribution of the Levack gneiss complex is the timing of ex-humation of the high-grade gneissic rocks (e.g., see Prevec etal., 2005, for a summary). Evidence increasingly points to sig-nificant pre-impact uplift and exhumation of the gneiss com-plex. U-Pb and 40Ar-39Ar cooling ages, combined with amphi-bolite facies decompression textures and field relationships,suggest that the Levack gneiss complex was initially unroofed

during the Neoarchean, broadly coincident with or immedi-ately preceding emplacement of the Cartier batholith (Fig. 5;e.g., James et al., 1991; Wodicka, 1997). Additional petro-graphic evidence supports a Neoarchean phase of exhuma-tion prior to intrusion of the 2.47 Ga Matachewan dikes(Siddorn and Halls, 2002). Geophysical evidence for a domal-uplift structure, underlying and orthogonal to the long axis ofthe Sudbury Igneous Complex, recently has been interpretedas resulting from early Paleoproterozoic, ca. 2450 Ma (syn-Huronian) rifting and magmatism in the region (e.g., Prevecet al., 2005), but it remains unclear whether or not this domalstructure also contributed to a period of rapid exhumation ofthe Levack gneiss complex. However, none of these studies

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1 km

1 km

OF

Hydrothermal“VMS”

Contact

Footwall

Offset

SICdebris flow

Chelmford Fm.

Onwatin Fm.

Onaping Fm.

Vermilion Fm.

Onaping intrusion

Dowling member

Sandcherry member Garson member

1.85

Ga

impa

ctite

s

granophyre

norite

quartz gabbro

sublayer

Offset dike

quartz diorite

inclusion quartz diorite

footwall breccia

Sudbury breccia

SIC

MA

IN M

AS

SW

HIT

EW

AT

ER

GR

OU

P

radial offset dike

concentric offset dike

Zn-Pb-Cu

Cu

Ni-Cu-Co

Cu-Pt-Pd-Au

Ni

Cu-Ag-Pt-Pd

Ni-Au

Zn-Cu

Kelly,Tottendeposits

A. Stratigraphy B. Ore Deposits

{{

metalliferous halo

FO

OT

WA

LL R

OC

KS

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. Notethe 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 kmfrom the Sudbury Igneous Complex. Offset deposits occur in inclusion-bearing quartz diorite along the offset dikes with themost distal offset deposit at ~7 km.

preclude the possibility that the 1850 Ma impact event repre-sents the mechanism responsible for the final exposure andpresent-day configuration of the previously retrograded gran-ulite facies rocks.

The Grenville Front

The boundary between the Southern and Grenvilleprovinces known as the Grenville Front trends northeast tosouthwest across the southeast corner of the map area (Map1, Fig. 2). It is defined by a prominent fault across which pre-dominantly gneissic rocks at middle to upper amphibolite fa-cies are abruptly juxtaposed against low-grade Huronian Su-pergroup rocks (predominantly Mississagi Formation),Nipissing gabbro, the Chief Lake complex, and undeformedSudbury dikes. Detailed remapping of the Grenville Frontduring the last 15 years in the vicinity of the town of Conistonand in Street township (Map 1) has resulted in an improvedunderstanding of the nature of the front (Davidson, 2001;Easton and Murphy, 2002, and references therein). South-west of Coniston, the Grenville Front boundary fault is amoderately to steeply southeast-dipping thrust. Mylonite and

ultramylonite are progressively developed toward the fault inboth the footwall and hanging wall of the fault. At Conistonthe thrust fault is truncated by the vertical Murray fault, thenortheastward continuation of which is known as the Wanapiteifault. These field relationships imply that the Murray fault, aprominent structure with a long pre-Grenvillian history (e.g.,Card et al., 1972; Farrow and Lightfoot, 2002; Spray et al.,2004), was reactivated during the Grenvillian orogeny.

Mineral DepositsSudbury rivals Norilsk as the world’s largest nickel camp, and

it also produces significant amounts of Cu, Co, Pt, Pd, Au, andAg. The Sudbury mining camp has close to 90 Ni-Cu-PGEdeposits, including 14 currently operating mines, numerouspast producers, and several advanced prospects (Fig. 8).Lesser known are the past-producing Zn-Pb-Cu-Ag hy-drothermal massive sulfide deposits that are situated abovethe Sudbury Igneous Complex (Figs. 7, 8, 9). Over 425 minesand occurrences are indicated on Map 1 and listed in Table 1.The surface projections of the historic and current Ni-Cu-PGE and Zn-Pb-Cu mineralization displayed on the map are

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10 km

SIC

Occurrence

Past ProducerProducerAdvancedProspect

Ni-Cu-Co

Cu-Ni-Pt-Pd-AuZn-Pb-CuAuCu-Au

N

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

based on data from FNX Mining Company Inc., Vale-INCOLtd, and Xstrata Nickel (Fig. 9). Several past producers ofgold, copper, and uranium also occur in the region, althoughthey are temporally unrelated to the 1.8 Ga Sudbury impact.

About half of the total past production and current re-sources of Ni, Cu, and PGE is associated with the basal con-tact of the Sudbury Igneous Complex; ~25 percent occurs inthe offset environment and ~25 percent in the footwall envi-ronment, all in breccias proximal to the base of the SudburyIgneous Complex (Fig. 7). Significant host rocks for Ni-Cu-PGE mineralization in Sudbury include footwall breccia (unit35) and sublayer (unit 40) in the basal contact environment ofthe Sudbury Igneous Complex; inclusion-rich “quartz diorite”(unit 36) in the offset environment, and Sudbury breccia (unit34) that developed in a variety of Neoarchean and Paleopro-terozoic rocks in the stratigraphic footwall of the SudburyIgneous Complex. Photographs of outcrops, polished rock

slabs, and photomicrographs of ore textures of the Ni-Cu-PGE mineralization are shown for the various ore environ-ments (Ames, 2007a).

The footwall geologic environment is least understood,with deposit models evolving as new styles of economic min-eralization are found in the mining camp. Cu-rich depositshosted in the Sudbury Igneous Complex footwall environ-ment have significant precious metal contents, typically >6 g/tPt + Pd + Au + Ag (i.e., Strathcona deep copper: Abel et al.,1979; Farrow and Lightfoot, 2002). Low-sulfide, high PGE-Au, Ag deposits represent a recently recognized style of min-eralization in the district and are a potential future source ofsignificant PGE-Au production. The first economic depositmined of this type was at the McCreedy West deposit, PMzone, mined in 2005 (Farrow et al., 2005), which had typicalgrades of 0.3 percent Ni, 1.0 percent Cu, >5 g/t (Pd + Pt +Au) and low sulfide content (<3 wt % S). The disseminated

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N

SICSIC

70

45

77

7565

40

44

50

50

48

67

60

85

68

70

6440

35

37

44

Errington-Vermilion deposits

Zn-Pb-Cu

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.)

sulfides with elevated precious metal contents are hosted instrongly brecciated, pseudotachylitic footwall rocks (SudburyBreccias, unit 34). Current exploration for this type of ore isextensive in the vicinity of known Ni-Cu mines. Low-sulfide,high-PGE mineralization is also recognized at the Levackmine (north 148 zone), Levack Footwall, Victor, Capre (3000zone), Ni Rim South, Broken Hammer, Crean Hill, and Lit-tle Stobie.

The 6.4 Mt Errington-Vermilion Zn-Pb-Cu deposits (Ameset al., 2006; Ames, 2007b) occur in the Whitewater Group,stratigraphically ~1.5 to 2 km above the Sudbury IgneousComplex. These base metal deposits have regional semicon-formable alteration zones in the footwall that were dated at1848.4 ±1 Ma (modified from Ames et al., 1998; see Table 2).Heat from the Sudbury Igneous Complex caused hydrother-mal convection above the melt sheet. VMS-like Zn-Pb-Cu de-posits formed in the crater fill above the Sudbury IgneousComplex, and the Ni-Cu-PGE deposits below the complexwere modified by hydrothermal activity (fig. 11 in Ames et al.,2006).

The new compilation map of the Sudbury district providedin this issue integrates the geology, geochronology, impactfeatures, and metallogeny across 9 NTS (National Topo-graphic System) sheets, covering about 80 × 60 km, and pro-vides the most up-to-date tectonostratigraphic frameworkfor resource exploration and development, education, andresearch.

AcknowledgmentsDiscussions with numerous Sudbury explorationists and

academic and government geologists have been invaluable.Particularly, Ken Card, Catharine Farrow, Harold Gibson,Paul Golightly, Peter Lightfoot, Gordon Morrison, and Ed-ward Pattison have openly provided insights into the intrigu-ing world of Sudbury geology and the development of one ofthe world’s premier polymetallic mining camps. Constructivecomments and reviews by Wouter Bleeker, Michael Easton,and John Spray are gratefully acknowledged. We thank JohnBuckle, Darren Viner, and Beth Hillary for GIS developmentof the Sudbury map. This is GSC contribution number20080189.

January 14, July 16, 2008

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——2007a: The supergiant Ni-Cu-PGE Sudbury district, Ontario, Canada.in Goodfellow W.D., ed., Mineral deposits of Canada: A synthesis of majordeposit-types, district metallogeny, the evolution of geological provinces,and exploration methods: Geological Association of Canada, Mineral De-posits Division, Special Publication no. 5, Ore Photo library on DVD, 111figures.

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