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Table 1. of Precambrian rocks, Phanerozoic ultrabasic intrusions and kimberlite pipes. MARGINAL NOTES At the edge of the James Bay Lowland in Ontario, the OSD includes a Heaman, L.M., Kjarsgaard, B.A. and Creaser, R.A. 2003. The timing of 87°W 86°W 85°W 84°W 83°W 82°W 81°W 80°W calc-alkalic metavolcanic sequence containing volcanic-hosted massive kimberlite magmatism in : implications for global abc Map Rock Type Reference UTM UTM UTM Crystallization Maximum Inherited Metamorphic ЄNd DePaolo sulphide deposits at McFaulds Lake (Map No. 47), with a U/Pb zircon LEGEND The relatively flat-lying and James Bay lowlands form a broad, kimberlite genesis and exploration; Lithos, v.71, p.153-184. No. zone east north Age (Ma) Deposition Age (Ma) Age (Ma) Nd Model SHRIMP age of 2737±7 Ma (Rayner and Stott 2005). This is comparable dominantly carbonate, Paleozoic to Mesozoic cover over a significant Age (Ma) Age (Ga) in age to the Confederation assemblage in the Uchi domain. In this = portion of the Precambrian rocks in . This has impeded Heaman, L.M., Kjarsgaard, B.A. and Creaser, R.A. 2004. The temporal PHANEROZOIC respect, it is noteworthy that the aeromagnetic evidence shows a 1 quartz-rich wacke 1 15 503609 5995692 2863.2±0.7 our understanding of the Precambrian geology and tectonic framework evolution of North American kimberlites; Lithos, v.76, p.377-397. discontinuous chain of greenstone belts, extending from the Uchi domain, 2 biotite granite 1 15 513188 5992377 2723±6 across this region of Ontario and its relation to adjacent areas in CENOZOIC Ontario Geological Survey wrapping around and joining the OSD, east of the McFaulds Lake and Québec. Consequently, this set of maps is designed to provide an Janse, A.J.A., Downie, I.F., Reed, L.E. and Sinclair, I.G.L. 1989. Alkaline 3 quartz+feldspar porphyry 1 15 518939 6047828 2717±3 belt (Stott and Rainsford 2006). Overall, both the Meso- and Neoarchean interpretation of the Precambrian geology underlying the Hudson Bay intrusions in the , Canada: exploration methods, 4 hornblende+biotite tonalite gneiss 1 15 519988 6022428 2848±7 supracrustal belts of the OSD appear to be dominated by juvenile, oceanic QUATERNARY and James Bay lowlands based mainly on available re-processed petrology and geochemistry; in Kimberlites and Related Rocks, v.2, Ross, crust formed without significant input from adjacent older terranes except MAP P.3598–Revised 5 aphyric dacite tuff 1 15 519989 6047178 2726±2 2742, 2752 aeromagnetic data (OGS 1999, 2003; GSC 2003) and limited diamond- J., Jaques, A.C., Ferguson, J., Green, D.H., O’Reilly, S.Y., Danchin, R.V. close to the North Kenyon fault and the Northern Superior superterrane. 6 biotite tonalite 1 15 522267 5986363 2863.3±0.7 drill hole information (McIlraith and Stott 2005). Much of the interpretation and Janse, A.J.A. (eds.), Geological Society of , Special Publication 56°N PLEISTOCENE AND RECENT 7 conglomerate 1 15 522717 5985941 2863.8±0.7 is anchored by comparing similar aeromagnetic features in the exposed 14, Blackwell Scientific Publications, p.1193-1203. Uchi Domain UNCONFORMITY PRECAMBRIAN GEOLOGY 8 quartz-rich conglomerate 1 15 522788 5985927 2865±1 portions of the Archean Superior Province and the Paleoproterozoic Trans-Hudson Orogen in Ontario, Manitoba and Québec. The results Kamo, S.L. 2008. U-Pb ID-TIMS geochronology of late tectonic rocks from 9 15 arkose 1 523989 6044128 2713±5 provide a general framework of interpreted supracrustal belts, plutonic The Uchi domain forms the southern part of the North Caribou terrane an intrusive complex in the Hudson Bay Lowlands, Ontario; unpublished PRECAMBRIAN 10 sandstone 1 15 526778 6026659 2722.6±2.7 subdivisions, major faults and Proterozoic mafic dikes. A Miscellaneous where magmatic U/Pb zircon ages and Nd model ages indicate the report for the Ontario Geological Survey, 6p. HUDSON BAY AND JAMES widespread presence of 2.8 to 2.9 Ga crust, comparable to the Island 11 fragmental felsic volcanic 1 15 527687 6031850 2718.2±1.0 Release–Data (MRD 233) digital publication accompanies maps Lake domain forming the north flank of the NCT. The Uchi domain Kong, J.M., Boucher, D.R. and Scott-Smith, B.H. 1999. Exploration and 15,12 MESOPROTEROZOIC 12 hornblende granodiorite 1 15 527589 6050927 2715±8 2747 P.3597-Revised to P.3599 inclusive. It includes the shapefiles for all 3 BAY LOWLANDS REGION maps and a seamless map of the lowlands; sets of seamless regional includes circa 2887 Ma Pembina tonalite on Lake St. Joseph and 2860 geology of the Attawapiskat kimberlites, James Bay Lowlands, northern 13 quartz+feldspar porphyritic rhyolite 1 15 528034 6030203 2722.5+6.1/-4.4 aeromagnetic and gravity images; Landsat images and digital elevation Ma Pickle Crow porphyry (Corfu and Stott 1993) in addition to pre-2.8 Ga Ontario, Canada; Seventh International Kimberlite Conference, 35 Alkalic Intrusive Suite and Carbonatite (circa 1.0 to 1.2 2 volcanic assemblages. The Uchi domain was constructed largely by 6 14 sandstone 1 15 528218 6028675 2709.4±1.7 Extended Abstracts, Cape Town, South , p.446-448. b Ga): alkalic syenite, ijolite, associated mafic and INTERPRETED FROM model (DEM) of the lowlands; tables of geochronology, kimberlite pipes, HUDSON BAY 15 quartz porphyry in mafic volcanic 1 15 530988 5978727 2857±2 diamond-drill hole information, and AFRI files. It also includes contoured autochthonous, episodic additions of volcanic assemblages and ultramafic rocks, and carbonatite accompanying plutons during the Neoarchean era (Stott and Corfu 1991). LeCheminant, A.N. and Heaman, L.M. 1989. Mackenzie igneous events, 16 hornblende granodiorite 1 15 531389 6042727 2710±6 estimates of depth to Precambrian basement in shapefile and pdf formats, 15,12 35a Carbonatite and related rocks AEROMAGNETIC DATA with notes. The following notes are an expansion of Stott and Rainsford Neoarchean assemblages, forming the core of the Uchi domain, appear Canada: Middle Proterozoic hotspot magmatism associated with 17 sandstone 1 15 534147 6030004 2718.7±2 (2006). to have built upon or lie adjacent to the NCT Mesoarchean crust. The opening; and Planetary Science Letters, v.96, p.38-48. 25b,15,12 34 Mafic and Related Intrusive Rocks 18 felsic tuff 1 15 534147 6030004 2720.9±0.9 eastern extent of the Uchi domain underlies the James Bay Lowland (circa 1.0 to 1.2 Ga) 19 biotite tonalite 1 15 560489 6007926 2855±5 2758 where, from high-resolution aeromagnetic images, it appears to merge Manitoba Geological Survey 2005. Manitoba geochronology database; 34c Ultramafic, gabbroic and granophyric intrusions EAST SHEET Methodology with the OSD. The resulting merged greenstone–granite domain continues Manitoba Industry, Economic Development and Mines, Manitoba POLAR 20a carbonatite 1 15 563590 6069227 1822±96 eastward under the James Bay Lowland on strike with the Geological Survey, Open File Report 2005-3, digital Web release. 25b,15,12 33 Mafic Intrusive Rocks 21 biotite granodiorite 1 15 569291 6091076 2846±5 2872 2717 A composite image was used for interpreting the regional geology based greenstone–granite domain of Québec. BEAR on the shaded relief of both colour total field and greyscale first vertical 33a Mackenzie mafic dike swarm (1267 Ma) Scale 1:500 000 22 15 2732.4±1.0 2 fragmental felsic volcanic 1 572780 6040336 McIlraith, S.J. and Stott, G.M. 2005. Lowland drill hole data compilation; 6 derivative of the regional aeromagnetic survey in Ontario (OGS 1999) b 23 biotite tonalite 1 15 573664 6073414 2822.0±0.8 Proterozoic Mafic Dikes Ontario Geological Survey, Miscellaneous Release—Data 152. INTRUSIVE CONTACT plus the colour shaded relief images of first and second vertical PROVINCIAL 10000 m 0 5 10 15 20km 24 biotite granodiorite 1 15 574901 6078016 2722.5±2 derivatives of a high-resolution aeromagnetic supergrid (OGS 2003) Several mafic dike swarms have been identified across Ontario Ontario Geological Survey 1999. Single master gravity and aeromagnetic 25b,15,12 25 hornblende+biotite tonalite gneiss 1 15 576191 6085526 2814±4 3209, 3572 2741 covering a significant part of the James Bay Lowland and straddling a PARK PALEOPROTEROZOIC (e.g., Osmani 1991; Buchan and Ernst 2004) and some of these extend data for Ontario; Ontario Geological Survey, Geophysical Data Set small portion of the Hudson Bay Lowland. After experimenting with NTS Reference: 43 A,B,C,D,E,F,G,H,J,K,L,M,N,O 26 biotite tonalite gneiss 1 15 580041 6101226 3292, 2854 into the lowlands region. The most prominent, especially in the James 1036. various images of the data sets, this combination provided a reasonable 27 Carbonatite–Alkalic Intrusive Suite (circa 1.8 to 1.9 Ga) 27 granite dike 1 15 580041 6101226 2690-2711 Bay region, is the northwestward-radiating Matachewan dike swarm. tool for interpreting the Precambrian substrate under the lowlands and 25b,15,12 Many of these, circa 2450 Ma, dikes are grouped into several “bundles” Ontario Geological Survey 2003. Ontario airborne geophysical surveys, ©Queen’s Printer for Ontario, 2008. 28 biotite tonalite 1 15 585390 6038676 2733.7±1.7 2849±12 was compared with the first vertical derivative Bouguer gravity map (OGS 25b,15,12 of more closely spaced dikes, including one bundle that passes through magnetic data, grid data, magnetic supergrids; Ontario Geological 25c,26a 29 foliated tonalite 1 15 587062 6081622 2701.1+4.0/-1.8 2745, 2840 1999) in assessing the locations of probable greenstone belts in areas 26 Mafic Intrusive Rocks the Attawapiskat cluster of kimberlite pipes. Most of the Attawapiskat Survey, Geophysical Data Set 1037. This map is published with the permission of the Director, Ontario outside the high-resolution aeromagnetic supergrid. Most of the 30 hornblende granodiorite 1 15 591879 6044115 2718.7±1.5 kimberlites are aligned parallel to and alongside one of the Matachewan Geological Survey. interpretations were done on transparent sheets, which were subsequently 25b,15,12 26a Sutton Inliers: gabbroic sills of the Molson event 31 gabbro 1 15 591290 6075281 2716±1.3 dikes (see Figure 2), indicating that these Jurassic pipes took advantage Ontario Geological Survey 2006. 1:250 000 scale bedrock geology of 25b 55°N digitized into geographic information system (GIS) format. Aeromagnetic (circa 1880 Ma) of this Paleoproterozoic vertical dike sheet, close to the Winisk fault, to Ontario; Ontario Geological Survey, Miscellaneous Release—Data 32 intermediate tuff 1 15 591575 6072948 2718.1+2/-1.8 relief was enhanced by shading at 45° inclination from three different 25c,26a 126-Revised. 26b Pickle Crow mafic dike; normally magnetized northwest- 9 inject through the crust from the lithospheric mantle (Stott 2003). It should 5° 90° 75° 33 hornblende granodiorite-monzonite 1 15 595691 6077926 2714±8 2813, 2720 directions (000°, 315° and 045°), which provided improved definition of trending subswarm (Molson swarm) (circa 1876 Ma) Thomp 85° 80° also be noted that a few of the Matachewan dikes cross the Winisk fault 25b 25b son ba Hudson Bay 34 quartz+feldspar porphyry 1 15 603214 6041472 2730.4±1.3 2735.6±2.2 various features trending in different directions, especially the mafic dikes, to without aeromagnetic evidence of lateral offset, indicating that the principal Osmani, I.A. 1991. Proterozoic mafic dike swarms in the Superior 25b 25b 55° ni faults and lithologic contacts. In the absence of descriptions from any drill 25b 278 m 26c Pickle Crow mafic dike; reversely magnetized a 35 plagioclase porphyry 1 15 6014137 2724.6±1.0 2715.1±1.5 2 25b 25c,26a M P.3597– 613019 dextral movement on the Winisk fault pre-dated the circa 2450 Ma Province of Ontario; in , Ontario Geological Survey, 6 308 m core of Precambrian rocks underlying the lowlands, generalized b 25c,26a 25b northwest-trending subswarm (Molson swarm) 36 hornblende granodiorite 1 15 613376 6069023 2716.2±1.2 Matachewan dikes and was therefore likely late Archean in age. Another Special Volume 4, Part 1, p.661-681. 25c,26a 25c,26a Revised interpretations were made of the probable rock types based on comparable 25c,26a (circa 1876 Ma) P.3598– prominent dike swarm, the Marathon dikes, appears to have two trends James 37 felsic tuff 1 15 622884 6060853 2718.1±0.9 aeromagnetic characteristics in the exposed part of the Superior Province 26d Mafic plutons of uncertain age; gabbro, diorite, quartz Revised Bay south and southwest of the James Bay Lowland (Halls, Stott and Davis Parks, J., Lin, S., Davis, D. and Corkery, T. 2006. New high-precision 25b,26a 25c,26a 25c,26a 38 rhyodacite tuff 1 15 628783 6059926 2838±1.1 2846.6±1.3 outside of the lowlands. 25b 25b diorite 2005; Halls et al. 2008), corresponding to two separate episodes of U-Pb ages for the Island Lake greenstone belt, northwestern Superior 25c,26a b 25b 55°N 39 feldspar porphyritic granodiorite 2 16 403925 6104905 2726±6 (max) ca. 2780 -1.69 3.10 intrusion; the north-trending dikes are circa 2101 to 2110 Ma in age and Province: implications for regional stratigraphy and the extent of the Winisk 25c,26a 25c,26a INTRUSIVE CONTACT 2710±7(min) one of the northeast-trending dikes is dated at about 2126 Ma. Similar North Caribou terrane; Canadian Journal of Earth Sciences, v.43, ! General Features 25b,15,12 b quartz-rich grit at Precam.-Paleoz. contact 2 16 403925 6104905 north-trending dikes under the James Bay Lowland, inferred to be related p.789-803. P.3599 40 2668 to 2745^ 25c,26a Q 25b 25 Trans-Hudson Orogen Supracrustal Rocks 5 Kenora 0 u b to the Marathon swarm, appear to have a close spatial association to the 0 Wi ° 41 tonalite-quartz diorite 2 16 440617 5946704 2727±4 0.83 2.84 Some of the magnetically inferred trend lines are highlighted on the map 25a Mafic and ultramafic metavolcanic rocks, nnipeg é Kyle Lake kimberlite pipes of circa 1100 Ma (Keweenawan) age, implying Percival, J.A., Sanborn-Barrie, M., Skulski, T., Stott, G.M., Helmstaedt, H. 12,11 Dry b b 25b den e metasedimentary rocks, differentiated mafic to c 42 granodiorite 2 16 475190 5945618 2696±3 2886±12 0.03 2.91 (shown as the “Inferred foliation and/or bedding trend” line style) to a role played by these dikes in controlling the emplacement of kimberlites and White, D.J. 2006. Tectonic evolution of the western Superior 25b 27 25c,26a POLAR 25b ultramafic intrusions of the Fox belt 43b tonalite gneiss 2 16 484785 5961820 2683±5 2729±5 0.89 2.78 illustrate the overall pattern of trends corresponding to planar lithologic similar to the Matachewan dikes. Other dike swarms that transect the Province from NATMAP and Lithoprobe studies; Canadian Journal of Timmins 2 r BEAR contrasts, bedding or contacts. Generally, west- and northwest-trending 6 25b e 25b Undifferentiated clastic and carbonate metasedimentary Thund b c v er 44 tonalite to granodiorite gneiss 2 16 485636 5964254 2813±4 ca. 2740 Archean crust, under the Paleozoic cover rocks of the lowlands, include Earth Sciences, v.43, p.1085-1117. i 25b 1.70 2.86 R Bay faults show evidence of dextral transcurrent displacement and northeast- PROVINCIAL rocks k U.S.A Lake b the northwest-trending Mackenzie dikes (1267 Ma, LeCheminant and s 45 biotite tonalite gneiss 16 2700±4 i Superior 2 492417 5945180 0.91 2.83 trending faults show sinistral displacement. Sites where radiometric ages 25b n 25c Sutton Inliers - Sutton Ridges Formation: unsubdivided i PARK Heaman 1989) and the north-northeast-trending and north-northwest- Rayner, N. and Stott, G.M. 2005. Discrimination of Archean domains in bury b W Sud 46 biotite tonalite to granodiorite 2 16 498283 5963777 2715±5 of rock units were obtained are numbered on the map face and 12,11 clastic metasedimentary rocks (including wacke, trending Molson dikes. The latter set of Molson dikes, the Pickle Crow the Sachigo Subprovince: a progress report on the geochronology; in 25c,26a Sault ttawa b summarized in Table 1. Kimberlite pipes are shown and numbered, er siltstone, argillite and conglomerate), and iron formation O 47 intermediate volcanic (McFaulds Lake) 2 16 563126 5850462 2737±7 Summary of Field Work and Other Activities 2005, Ontario Geological iv 25c,26a Ste. Mar 1.13 2.84 subswarm, based on on-strike extension and parallel-strike to the Pickle R ie 25b n 45° Lake b corresponding to the list in Table 2. Most of the lowlands are underlain by 0 m o 25d Sutton Inliers - Nowashe Formation: carbonate Crow dike of 1876 +/- 8 Ma Ar-Ar age (Buchan et al. 2003), appears to Survey, Open File Report 6172, p.10-1 to 10-21. tt 48 hornblende-biotite quartz diorite to diorite 2 16 593549 5824221 2724.3±0.8 25c,26a u Huron Archean rocks but a broad area across the northern half of the Hudson S metasedimentary rocks (dolomite, cherty dolomite, b trend across a north-northeast-trending set of dikes near the Manitoba 25b 49 quartz diorite 2 16 605500 5832171 2728±5 1.44 2.80 25c,26a 25c,26a 25b stromatolitic dolomite, argillaceous dolomite) Bay Lowland lies within the Trans-Hudson Orogen (THO). Part of this border. This north-northeast-trending set of dikes are assigned to the Reed, L.E. and Sinclair, I.G.L. 1991. The search for kimberlite in the James 25c,26a Location Map 1 cm equals 200 km b 26a 25e Undifferentiated clastic metasedimentary migmatite 50 quartz diorite 2 16 621021 5864670 2710±4 2.44 2.71 area is interpreted as Archean granitoid rock overprinted by the THO. 2 25b Biscotasing dike swarm, circa 2175 Ma, based on an unpublished Bay Lowlands of Ontario; Canadian Institute of Mining and Metallurgy 6 0 m b b 51 quartz-rich grit at Precam.-Paleoz. contact 2 17 306189 5854792 2664 to 2770^ Much of the THO is represented by a broad, folded metasedimentary baddeleyite age from a dike near North Spirit Lake, south of Map P.3597– Bulletin, v.84, no.947, p.132-139. basin, incorporating iron formation, most notably in the exposed Sutton INTRUSIVE CONTACT 52c MacFayden 1 kimberlite 3 17 301516 5862943 177.2±1.3 Revised (M.A. Hamilton, Jack Satterly Geochronology Laboratory, 15,12,25b 25b Inliers and their folded continuity northwards under the Paleozoic rocks 53c 17 179.9±1.6 University of Toronto, personal communication, 2008). Sage, R.P. 1991. Alkalic rock, carbonatite and kimberlite complexes of Peawanuck Charlie (C1) kimberlite 3 302167 5861400 toward Hudson Bay. ! 23 Mafic Dikes SYMBOLS d Ontario, Superior Province; in Geology of Ontario, Ontario Geological 54 Uniform (U1) kimberlite 4 17 303979 5863163 180 15,12, 26a Phanerozoic Intrusions Survey, Special Volume 4, Part 1, p.683-709. 15,12,25b 170 m 25b 25c,26a 55f Golf (G1) kimberlite 5 17 309956 5866796 156±2 These maps display a composite of the bedrock geology of the northern 25b Geologic contact, Terrane boundary portion of the Archean Superior Province in Ontario. The regional terranes 15,12,25b 25b 23a Marathon mafic dike; north-northwest- to north- interpreted 56f Alpha-1North kimberlite 5 17 312386 5842382 156±2 Apart from the Attawapiskat kimberlite pipe cluster described below under Sage, R.P. 2000. Kimberlites of the Attawapiskat area, James Bay and domains are shown in Figure 1, based on Stott et al. (2007). Some 15,12,25b 15,12,25b 25c,26a northeast-trending subswarm (circa 2101 to 2110 Ma) (trend only) 57c Bravo "A" kimberlite 3 17 305529 5857130 179.4±2.2 “Economic Considerations”, two clusters of mafic to ultramafic pipes and Lowlands, northern Ontario; Ontario Geological Survey, Open File interpreted features to note: 33 Provincial park Report 6019, 341p. a 25c,26a 58c Bravo "B" kimberlite 3 17 305529 5857130 175.7±1.8 diatreme heterolithic breccias occur near the southern margin of the James 15,12 25b 23b Marathon, or Biscotasing mafic dike; Area of inferred Bay Lowland and are described by Sage (2000). The western cluster 59c Kyle 1 kimberlite 4 16 608467 5813846 1123±20 • The merging of greenstone belts of Uchi domain and Oxford–Stull northeast-trending subswarm (circa 2124 or 2170 Ma) Trans-Hudson (Figure 2.1 of Sage, 2000), north of Hearst, occurs just northeast of the Sandford, B.V. and Norris, A.W. 1975. Devonian stratigraphy of the c domain under the James Bay Lowland; 55°N 25b,15,12 JAMES BAY Orogen overprint on First Nation reserve 60 Kyle 5 alnoite 4 16 616617 5882214 1076.2±3.8 Hudson Platform; Part I: stratigraphy and economic geology; Department 2 Martison carbonatite and lies mainly between two parallel, northeast- 15,12 6 • A large indentor-like feature underlies the James Bay Lowland, flanked c 23c Biscotasing mafic dike; north-northeast-trending Archean crust 61b granodiorite gneiss 2 16 609277 5787608 2690±3 2787±6, -0.34 2.95 trending faults. Two potassium-argon ages on phlogopite from alnoite of Energy Mines and Resources Canada, Memoir 379, 124p. 0 m by faults (see Map P.3599); 5 3 15,12 subswarm (circa 2175 Ma) ca.2900 pipes in this cluster give 152 +/- 8 Ma and 180 +/- 9 Ma, which compare 3a 25b 25b • The separation of English River and Quetico metasedimentary domains Skulski, T., Corkery, M.T., Stone, D., Whalen, J.B. and Stern, R.A. 2000. !!! Approximate area Township K-feldspar megacrystic granodiorite -1.11 2.95 with the age range of Attawapiskat kimberlite pipes (Janse et al. 1989, 15,12 25b !!! of “Sutton Inliers”, 62 6 16 372388 6072085 >2705±2 south of the James Bay Lowland by a ridge of felsic plutonic rocks, Geological and geochronological investigations in the Stull Lake– 0 m !!!! as reported by Sage 2000). The second cluster of diatreme breccias and 17 !!! 3.02 with high magnetic field intensity, extending westward from the Opatica 25b 25c Mafic Dikes !! with outcrops or 63 quartz diorite 6 16 373801 6065609 2709.1±0.8 -1.06 alkalic ultramafic dikes occurs near Coral (Sextant) Rapids, on and west Edmund Lake greenstone belt and granitoid rocks of the northwestern 25d,26a 25c,26a gneisses of Québec. The Opatica terrane might extend to the Marmion 0 m 25c,26a 25b 17a Matachewan mafic dike; northwest-trending swarm thin Paleozoic cover Road, trail, e alkalic ultrabasic diatreme breccias 306976 5573404 Superior Province; in Report of Activities 2000, Manitoba Industry, 25b,15,12 26a 25d 64 7 17 152±8 of (Figure 2.2 of Sage, 2000). There may be a broad array of 15,12 0 m 0 m terrane where the latter is interpreted to underlie most of the eastern 2 26a 25c (circa 2454 Ma) railroad e Phanerozoic ages for intrusions in this cluster. Sage (2000) reports that Trade and Mines, Manitoba Geological Survey, p.117-128. 6 26a 26a 65 alkalic ultrabasic diatreme breccias 7 17 336646 5574811 180±9 Wabigoon Subprovince; b Iron formation c one of the ultramafic diatreme pipes was dated (U/Pb on perovskite) 66 alkalic ultrabasic diatreme breccias 8 17 439311 5574837 235.6±2.2 • The Trans-Hudson Orogen, including areas of reworked Archean crust, 0 m 25c INTRUSIVE CONTACT Powerline at 235.6 +/- 2.2 Ma, Triassic age, by L.M. Heaman (University of Alberta, Stone, D. 2005. Precambrian geology, northern Superior area; Ontario Goldray carbonatite 493247 5586109 appears to underlie the northern half of the Hudson Bay Lowland, 0 m 67 9 17 1884±2 unpublished data, 1997). A potassium-argon Cretaceous age on a Geological Survey, Preliminary Map P.3545, scale 1:250 000. 276 m based on interpretation of aeromagnetic maps; 25b Fault, interpreted; 68g Argor carbonatite 9 17 525869 5629661 1950 lamprophyric dike of 128 +/- 18 Ma was obtained by Sandford and Norris 25d,26a 25b,26a ARCHEAN • Apparent reworked Archean Northern Superior superterrane crust under 0 dextral horizontal Town (1975). Stone, D., Corkery, M.T., Hallé, J., Ketchum, J., Lange, M., Skulski, T. Notes and Abbreviations the Hudson Bay Lowland within the Trans-Hudson Orogen; 15,12 displacement ! and Whalen, J. 2004. Geology and tectonostratigraphic assemblages, r 300 m 25c,26a 16 2 Rive Pyroxenite, Diorite, Monzonite, Syenite • Broad areas of pronounced aeromagnetic field intensity characterize 6 isk 33 15,12 eastern Sachigo Subprovince, Ontario and Manitoba; Ontario b Win a Methods References large parts of the Northern Superior superterrane under the Hudson Economic Considerations 15,12 Fault, interpreted; Location of Geological Survey, Preliminary Map P.3462, scale 1:250 000. 25c All U-Pb zircon thermal ionization mass spectrometry (TIMS) except: 1. Stone 2005 (and references therein). Note that originally published UTM coordinates, sinistral horizontal ! 1 geochronology Bay Lowland in Ontario and lie on strike with the Pikwitonei gneisses, 15 Massive to Foliated Granodiorite to Granite 1 a Since the Hudson Bay and James Bay lowlands are covered by Paleozoic 25b 25b sample K-Ar biotite which were in NAD 27, have been converted here to NAD 83 values. including the Assean and Split Lake blocks, in Manitoba; Stott, G.M. 2003. Diabase dike swarms as structural controls for kimberlite 26a 25d,26a 15 25b,26a displacement b U-Pb zircon sensitive high-resolution ion microprobe (SHRIMP) 2. Rayner and Stott 2005. • Potential correlation of Northern Superior superterrane with the 3.8 Ga and locally Mesozoic rocks, an interpretation of the underlying Precambrian, 109 m 25d 25c,26a (keyed to Table 1) pipes under the James Bay and Hudson Bay lowlands, Ontario; 8th 0 m c U-Pb perovskite 3. Heaman and Kjarsgaard 2000. Porpoise Cove volcanics (David et al. 2002) in Tikkerutuk domain and mostly Archean, crustal structures has been greatly hampered in the past. Fault, interpreted; International Kimberlite Conference, Extended Abstracts, FLA317, 3p. 2 14 d This set of maps illustrates some interesting features that are relevant to 6 Diorite, Quartz Diorite: minor tonalite, monzonite, U-Pb perovskite (SHRIMP) 4. Heaman, Kjarsgaard and Creaser 2004. c unknown horizontal Location of kimberlite the >3.5 Ga Assean gneisses (Böhm et al. 2000); granodiorite, syenite and hypabyssal equivalents e K-Ar phlogopite 5. Kong, Boucher and Scott-Smith 1999. the economic characteristics of this region. The Precambrian geology of displacement ! 1 pipe • Areas interpreted to be part of the Paleoproterozoic Sutton Inlier are Stott, G.M. and Corfu, F. 1991. Uchi Subprovince; in Geology of Ontario, 15,12 0 m f Rb-Sr phlogopite 6. Kamo 2008. outlined where exposed. The Sutton “Inlier”, of shallow-water platform the lowlands region is composed of the Paleoproterozoic Trans-Hudson (keyed to Table 2) Ontario Geological Survey, Special Volume 4, Part 1, p.145-236. 25b,15,12 0 m POLAR 13 Muscovite-Biotite and Cordierite-Biotite Granite, g Pb-Pb 7. Janse et al. 1989. sedimentary units and overlying gabbro sill, does not appear to be one Orogen, occupying the northern half of the Hudson Bay Lowland, and the 0 m Inferred foliation 15,12 33 Granodiorite to Tonalite ^ Range of detrital zircon ages 8. Heaman, unpublished 1997 (in Sage 2000). large area but a set of inliers and should in future be referred to as the Kenoran Orogen, which dominates the rest of the region. Notably a 15,12 25c 25c 25b,26a BEAR and/or bedding trend Location of alkalic Stott, G.M., Corkery, T., Leclair, A., Boily, M. and Percival, J. 2007. A 12,11 ! 9. Kwon, unpublished 1986 (in Sage 1991). Sutton Inliers. The eastern Sutton Inliers with subsurface extensions overprinting the crustal units of these areas are major faults and 26a 25c,26a ultramafic diatreme revised terrane map for the Superior Province as interpreted from 0 m PROVINCIAL 12 Tonalite to Granodiorite: foliated to massive (See “References” section of Marginal Notes.) are shallowly dipping, northward concave and crescent-shaped, Proterozoic mafic (diabase) dikes. 0 m Lowlands boundary breccia pipe aeromagnetic data; in Woodruff, L. (ed.), Institute on Lake Superior 5,8 0 m 25c 12a Biotite tonalite to granodiorite based on aeromagnetic patterns, which correspond closely with the Geology Proceedings, 53rd Annual Meeting, Lutsen, Minnesota, v.53, 12,11 PARK 12b Hornblende tonalite to granodiorite distribution of outcrops observed by Bostock (1971). They resemble Kimberlite pipes in the James Bay Lowland (Sage 2000) are spatially Depth to Precambrian part 1, p.74-75. 15,12 0 m 25 m 25 m associated with Paleoproterozoic mafic (diabase) dikes (Stott 2003). 5,8 25b Granulite facies # " bedrock (from diamond- “klippe”, in their shape and shallowly northward dip, and might have 25b 11 Tonalite to Granodiorite: foliated to gneissic with minor Most notably the circa 156 to 180 Ma (Jurassic age) Attawapiskat 26a metamorphism  drill holes, from seismic been transported a short distance southwards. Folded strata related Stott, G.M., Davis, D.W., Parker, J.R., Straub, K.H. and Tomlinson, K.Y. 15,12 0 m supracrustal inclusions 0 m Table 2. Kimberlite pipes in the Hudson Bay and James Bay lowlands. cluster of kimberlites is mainly aligned along one of the northwest-trending data, from outcrop)a to the Sutton Inliers are shown aeromagnetically to extend 2002. Geology and tectonostratigraphic assemblages, eastern 25d 25c discontinuously northwards towards the Hudson Bay coast upon Matachewan dikes. Further west, the kimberlite pipes of the Kyle Lake 54°N Map No. Name Age (Ma) Map No. Name Age (Ma) Wabigoon Subprovince, Ontario; Ontario Geological Survey, 141 m 15,12 336 m 10 Gabbro, Anorthosite, Ultramafic Rocks a kimberlite group are approximately 1100 Ma in age (comparable to W 11,12 11,12 26a See Miscellaneous Release–Data 233 (MRD 233) for more specific apparently reworked Archean crust within the Trans-Hudson Orogen. i 33 Preliminary Map P.3449, Geological Survey of Canada Open n a i 1 K1 - Kyle 1123 ± 20 16 Bravo-B1 175.7 ± 1.8 Keweenawan intrusions along a northward extension of the Trans- s details. k 15,12 r 0 m File 4285, scale 1:250 000. R e 0 m INTRUSIVE CONTACT v Superior Tectonic Zone (Sage 1991)). They are more widely scattered in i i 2 K2 - Kyle 17 Victor-1 v Hudson Bay Lowland e R a southward direction but the individual pipes show a spatial correlation r 3 K3 - Kyle 18 Whisky 0 9 to a set of north-trending mafic dikes that are interpreted to be part of the Stott, G.M. and Rainsford, D.R.B. 2006. The Precambrian geology 25d,26a Coarse Clastic Metasedimentary Rocks: with minor, 119 m a 25d w 4 K4 - Kyle 19 AT 56 Northern Superior Superterrane underlying the James Bay and Hudson Bay lowlands as interpreted 15,12 a mainly alkalic, mafic to felsic metavolcanic rocks Marathon swarm. This consistent spatial association of pipes and dikes t t 3 15,12 a 3 15,12 from aeromagnetic data and a revised terrane map for northwestern m a 9a Metasedimentary rocks (conglomerate, arkose, arenite, 5 K5 - Kyle 1076.2 ± 3.8 20 X-Ray (and in some cases, local faults) in the lowlands implies that exploration a 5 h 25c,26a The Northern Superior superterrane (see Figure 1) forms a 1000 km long should focus not just on the major faulted terrane boundaries, such as Ontario; in Summary of Field Work and Other Activities 2006, Ontario S wacke, sandstone, siltstone, argillite) SOURCES OF INFORMATION 6 Golf-G1 156 ± 2 21 Delta-D1 0 11,12 band of distinctively strong magnetic intensity. Under the Hudson Bay the North Kenyon fault between the Northern Superior and Sachigo Geological Survey, Open File Report 6192, p.13-1 to 13-10. 7 Uniform-1 180 22 Yankee-1 8 Lowland in Ontario, broad areas of strong aeromagnetic intensity are superterranes, and the Superior Province–Trans-Hudson Orogen 5,8 25b 54°N Migmatized Supracrustal Rocks: metavolcanic and Digital base map information derived from the Ontario Land Information 8 Good Friday 23 Zulu-1 interpreted as late tectonic granodioritic batholiths similar to those that Thurston, P.C., Osmani, I.A. and Stone, D. 1991. Northwestern Superior 15,12 boundary (see Figure 1), but also close to major dike swarms that lie 0 m 0 m 25b,26a minor metasedimentary rocks, mafic gneisses of Warehouse, Land Information Ontario, Ontario Ministry of Natural 9 MacFayden-1 177.2 ± 1.3 24 X-Ray-1 dominate the magmatic arc just north of the Uchi domain (see Figure 1) Province: review and terrane analysis; in Geology of Ontario, Ontario 11,12 a uncertain protolith Resources, scale 1:20 000, and from 1:50 000 scale maps of the within the corridors of Jurassic kimberlite magmatism (Heaman, 3 15,12 26a 25b but overprinted by late Archean dextral shearing related to the Winisk Geological Survey, Special Volume 4, Part 1, p.26-57 15,12 2 25b 10 Unnamed 25 Delta-North Kjarsgaard and Creaser 2003) in Ontario and the corridor of Keweenawan 118 m National Topographic System (NTS), with modifications by staff of the fault. This superterrane contains U/Pb zircon ages of 3.2 to 3.1 Ga for 5,8 112 m 7 Metasedimentary Rocks: wacke, siltstone, arkose, magmatism defined roughly by the northward extension of the Trans- 5 5,8 25c Ministry of Northern Development and Mines. 11 MacFayden-2 26 Alpha-1N 156 ± 2 felsic plutonic rocks in the Assean Lake block in Manitoba, and detrital 120 m 15,12 0 m 25d,26a 25b argillite, slate Superior Tectonic Zone. 0 25c 12 Unnamed 27 Alpha-1 zircons in metasedimentary rocks up to 3.9 Ga in age (Böhm et al. 2000; Winisk 100 m 5,8 5,8 7a Wacke, siltstone, argillite The geological data is, in part, from OGS 2006, Stone 2005 and Stone 0 m 13 Tango-1 28 India-1 Böhm et al. 2003). Neodymium model ages (DePaolo 1981) range from The aeromagnetic interpretation of mafic dike subswarms, of different I.R. 90 11,12 26a 25b 7c Marble, chert, iron formation, minor metavolcanic rocks et al. 2004. (See “References” section of Marginal Notes.) 11,12 25c 14 Tango Extension 29 T1 Kimberlite circa 3.5 to 4.2 with εNd values to -10.5 at 2.7 Ga or older. Mesoarchean age and orientation, indicates that block rotation of the Superior Province 7e Paragneiss and migmatites 15,12 0 m (2.846 and 2.814 Ga) and Neoarchean plutonic rocks occur in the limited may have occurred episodically along major, reactivated Archean breaks 15,12 0 m 12,11 The aeromagnetic base underlying the geological interpretation on this 15 Charlie-C1 179.9 ± 1.6 30 U2 Kimberlite 2 0 m 6 exposure of the Northern Superior superterrane in Ontario with an inherited 15 6c Felsic to Intermediate Metavolcanic Rocks: rhyolitic, (faults). Dating of minerals along these faults might reveal the most active 3 15,12 0 m map is a greyscale shaded relief image of the first vertical derivative of 3 31 U1 Kimberlite age of 3.572 Ga and pre-3.0 Ga Nd model ages (Skulski et al. 2000). a 25c 0 m rhyodacitic, dacitic and andesitic flows, tuffs and periods of rotation, and it is these breaks that could have served as planar 3 the regional aeromagnetic survey (OGS 1999; GSC 2003), and a first 3a 5 25b 25c breccias, and related migmatites vertical derivative of a high-resolution aeromagnetic supergrid (OGS (See Table 1 for age determination methods and references.) corridors of crustal access for kimberlite pipes. 15,12 15,12 26a 25b Trans-Hudson Orogen 0 0 m 0 m 2003), both with illumination direction from 000° and declination 045°. 5 15,12 5 5 Near the southern margin of the James Bay Lowland and between two Mafic to Intermediate Metavolcanic Rocks: basaltic and 3 0 m 3 15,12 15,12 A marked magnetic discontinuity can be traced eastward roughly midway northeast-trending sinistral faults, a cluster of ultramafic alkalic diatreme a 12 14 andesitic flows, tuffs and breccias 8,5 1 1 0 m Informal division between Hudson Bay and James Bay lowlands. under the Hudson Bay Lowland between a region of high magnetic relief breccia pipes occurs, which was the target of diamond exploration in the 3 3 14 4 and complexity that characterizes the Northern Superior superterrane to 1970s (e.g., Reed and Sinclair 1991). These small pipes are recognizable WINISK a 0 m 0 m Mafic to Ultramafic Metavolcanic Rocks: basaltic and 26a 25c the south and a region of relatively flat magnetic character that more 3 8,5 25b, minor komatiitic flows, metasedimentary and pyroclastic rocks by their strong magnetic response but, although apparently related to the 3a 279 m 0 m 0 m 26a 0 m 5 CREDITS closely resembles the magnetic signature of the Trans-Hudson Orogen. Jurassic kimberlite pipes of the Attawapiskat cluster, they are not kimberlitic 8,5 15,12 15,12 0 m 12,11 12 12,11 25c 0 m 14 However, a significant portion of the interpreted Trans-Hudson Orogen or diamondiferous. Southeast of this cluster, the Martison carbonatite is of RIVER Opinnagau 0 m 26a 15,12 33 a a Lake 0 m 0 m Geological interpretation by G.M. Stott, 2007-2008. resembles, from the aeromagnetic image, an extension of the Northern 3 133 m 0 m Rock codes generally conform to Provincially Significant Mineral uncertain age but possibly associated with the Keweenawan magmatism, 3 15,12 0 m 2 25d 3 a 15,12 15,12 a Superior superterrane and is interpreted as an area of Archean crust that circa 1100 Ma. Its significant phosphate deposit has attracted recent 12,11 a 0 m Potential (PSMP) map codes (OGS 2006), with modifications. Number 3 3 5 3 2 12,11 0 m Preparation of base map, tables and digital by S. Josey. was overprinted by the Trans-Hudson Orogen. development interest by PhosCan Chemical Corporation. a codes subdivided into a, b, c, etc., are generally arranged from younger PROVINCIAL 5 26 15,12 25c c 0 m 12,11 to older. 15,12 The Sutton Inliers have been reinterpreted by comparing the aeromagnetic 12,11 b Cartographic production by A. Evers. The region bordering the lowlands within the Oxford–Stull domain has the 2 Some mafic dike swarms are tentatively subdivided into subswarms 6 10 3 0 m 0 m 2 JAMES BAY data and the outcrops mapped by Bostock (1971). Previous regional geology 3a c 15,12 3 15,12 a potential for hosting gold deposits comparable to similar Archean greenstone 54°N PARK 1 based on trend and inferred age corresponding to dike trends and 7 5 To enable the rapid dissemination of information, this map has not maps of Ontario portrayed the Sutton Inlier as a single large mass. This new belts elsewhere in the province. Numerous shear zones lie close to and a ages elsewhere in the exposed part of northern Ontario.

2 1 interpretation recognizes a set of ridges forming several crescent-shaped 3 received a technical edit. Discrepancies may occur for which the Ontario parallel to the greenstone belts just west of James Bay Lowland and south er 5 a 14 a c iv 3 This legend is common to all three maps in this set. Not all rock codes inliers that dip shallowly northward. They appear to be discontinuously R 2 Ministry of Northern Development and Mines does not assume liability. of Hudson Bay Lowland. These shear zones, generally trending east to 66 m n 8 wa 5 or symbols appear on all maps. 1 2 k related to similar but steeply dipping, folded, shallow-water sedimentary strata, E 0 14 Users should verify critical information. southeast, locally splay into the greenstone belts and could be a focus for 3 W 2 5 a IN 64 m a 5 3 including linear magnetic anomalies that probably define iron formation, within 12,11 a gold exploration in this region. Owing to the relative lack of Archean bedrock 5 I 65 m 3 15,12 S 2 1 12,11 the Trans-Hudson Orogen under the Paleozoic rocks closer to the Hudson Bay 8 K 3 7 5 Issued 2008. exposure, exploration for gold-bearing targets would require extensive 3 a a 15,12 FA 2 1 coast. surficial till sampling. U 6 L c 5 5 Information from this publication may be quoted if credit is given. It is 3 T 5 3 James Bay Lowland 8 a 0 recommended that reference to this map be made in the following form: Significant mafic to ultramafic intrusions occur close to the western margin 15,12 of the James Bay Lowland in the vicinity of McFaulds Lake. Recent 44 46 33 8 High-resolution aeromagnetic data (OGS 2003) and limited diamond-drill 11,12 a 11,12 15,12 Attawapiskat 91 12,11 Stott, G.M. 2008. Precambrian geology of the Hudson Bay and James discoveries of massive Cu-Ni-PGE mineralization in association with these 11,12 5 12,11 2 1 12,11 Bay lowlands region interpreted from aeromagnetic data – east 3 hole logs (e.g., McIlraith and Stott 2005) permit a clearer interpretation intrusions encourages the investigation of other intrusions, some of which 7 1 a a of the distribution of Archean supracrustal belts and granitic batholiths are newly discovered nearby. Most of these intrusions are poorly exposed 43 33 sheet; Ontario Geological Survey, Preliminary Map P.3598–Revised, a 15,12 15,12 10 under the Paleozoic cover of the James Bay Lowland. Perhaps the most and more are anticipated to be discovered with higher resolution 0 15,12 scale 1:500 000. 5 5 12,11 1 striking and significant feature is the aeromagnetic expression of Uchi geophysical data. These intrusions might form a coeval, late-tectonic suite 6 12,11 Ekwan Rive 33 2 r 11,12 5 2 a 2 3 81°W 3 domain greenstone belts, along the southern flank of the Sachigo that extends from Big Trout Lake along the southern margin of the Oxford– 6 a c a superterrane, trending northeast (see Figure 1) under the James Bay Stull domain to Highbank Lake on the edge of the James Bay Lowland N

10 a O 3 R 3 5 3 12,11 Lowland and wrapping around the eastern end of the Island Lake domain, and wrapping around a large granitic intrusion west of McFaulds Lake. 5 T a 2 H 5 12,11 r a portion of the Sachigo superterrane. This greenstone trend merges with e 1 Similar, coeval intrusions might also occur near the North Kenyon fault. 12,11 7 a 5 v a i 11,12 3 2 R 1 2 the Oxford–Stull domain near the western margin of the James Bay At this stage, one could speculate that these intrusions form a magmatic 3 2 2 k 2 7 a 3 s a 3 i 3 a 1 15 n a i 5 a 15,12 Lowland just east of the McFaulds Lake massive sulphide deposits, suite, derived from the mantle and intruded during the late stage of terrane 11,12 0 7 2 W 54 m 15,12 a 5 3 10 1 15,12 5 a currently under exploration by Spider Resources Inc. This combined collision along the boundaries of the Oxford–Stull domain as well as 7 10 15 5 12,11 15,12 a 5 5 array of Neoarchean greenstone belts continues east, narrowing under 45 K 1 bordering, possibly coeval, late-tectonic felsic plutons, such as the large E 2 1 7 N 6 7 1 a

Y c a 7 a 7 m a 2 12,11 O 11,12 a 3 10 the James Bay Lowland, towards the Eastmain greenstone–granite intrusive complex west of McFaulds Lake. 2 3 2 3 N 2 12,11 3 3 a 3 15,12 2 3 a 2 15,12 a domain in Québec. 2 2 a 3 1 3 12,11 3 a 1 a 1 12,11 7 a 7 Within the Paleoproterozoic Trans-Hudson Orogen that underlies the 3 a 0 a

0 3 a 5 a A northern greenstone limb of the merged Oxford–Stull and Uchi domains 15,12 5 3 2 1 northern half of Hudson Bay Lowland, the Sutton Inliers are suspected to 2 3 1 12,11 7 l a 5 7 1 1 11,12 a 12,11 e a 7 5 (see Figure 1), near the boundary with the Northern Superior superterrane, be similar in lithologies and age, circa 1960 Ma, to the Povungnituk Group n 10 2 a n 10,5 8 3 12,11 12,11 a 4 m a 12,11 appears to be dextrally offset by the Winisk fault, but on strike towards in the Cape Smith belt of northern Québec, the Nastapoka Group on the edge h 12,11 17 C F a A 15,12 10

s U a

i L the northern Eastmain greenstone–granite domain in Québec. 3 of Hudson Bay in western Québec, and the Flaherty Formation in the Belcher s T 8 5 11,12 1

i 2

k 2 0 15,12 a s

15 a 3 Group on the in Hudson Bay. The well-preserved gabbroic i 11,5 3 a 1 1

a 7 b 3 n 2 1 7 i 3 a 61 m 3 7 2 a 2 2 a sills that cap the shallow-water quartzite, iron formation and dolomite beds W 15,12 1 Some Features of Terranes and Domains 50 m 2 7 15 11,12 3 1 a 53°N have received some attention for potential Ni-Cu-PGE mineralization. 15 10,5 a 17 5 15 15,12 82 m 1 a 1 11,5 1 11 7a

7 2 a 1 2

Tectonically significant subdivisions in the northern Superior Province 7 a 3 3 3

a a 2 a 1 11,12 7 across Ontario have been progressively defined from field work, limited In the southwestern corner of the James Bay Lowland, a set of gabbro- 5 10 11 a 11,12 1 10 12,11 11 7 73 m 17 a 1 geochronology, isotopic studies and aeromagnetic interpretations syenite intrusions forms an arcuate chain that extends southward beyond b 82 m a 12,11 7 3 15 10,5 5 1 a 2 7 5 2 12,11 a 1 (e.g., Percival et al. 2006). The terrane and domain boundaries shown in the lowland cover. These intrusions resemble the ca. 1100 Ma Coldwell 10 7 3 0 5 a 12 a 1 12,11 2 Complex, on the north side of Lake Superior, in lithology and magnetic 5 2 Figure 1 incorporate and revise previous interpretations (e.g., Thurston, 3 15 15,12 3 1 11,12 2 a a 7 3 a intensity, and could draw attention to their PGE potential. The a 1 2 Osmani and Stone 1991; Stone 2005; Parks et al. 2006; Percival et al. 12,15 7 5 1 1 15 11 a 7 7 3 12,11 2 a 12,11 1 a a 2006; Stott et al. 2007). As in the southern Superior Province, terrane- southernmost intrusions of this arcuate chain are the most accessible for 7 3 11,12 1 a 2 7 a 6 a 1 12,15 7 12,11 11,5 2 c 11 2 exploration since Paleozoic cover rocks significantly increase in thickness 2 scale subdivisions, containing supracrustal and plutonic complexes 11 a 12 3 1 1 3 15 2 a 6 7 7 1 a a 3 15 a 3 b a 1 7

a 1 7 a 2 hundreds of kilometres long, are distinguished by lithology, age, isotopic northward over the northern intrusions of this suite. 10 7 a 10 12,11 1 5 1 0 a 11,12 7 11,12 7 2 12,11 8 character, geochemistry and bounding faults. Two sialic terranes, the a a 3

12 2 after 12,11 1 2 1 8 Figure 1. Regional tectonic subdivisions of northern Ontario ( Stott et al. 2007). a a 7 3 2 3 7

12,11 a 3 a a 12,11 a Northern Superior superterrane and the Sachigo superterrane, each have Acknowledgements 1 3 1 a 2 7 a 7 3 1 a a 2 2 M 12,11 1 7 ukete 7 complex, but distinct, episodic magmatic and tectonic histories. The 11,5 3 i R 12,11 a iv 1 2 a 1 1 5 a e 7 7 3 7 1 r 1 b a 12,11 7 a a D.R.B. Rainsford of the Ontario Geological Survey provided helpful insight 7 1 3 a 8 Northern Superior superterrane contains remnants of a magmatic record 0 2 12,15 a 15 11,12 1 5 a a 7 2 12,11 1 7 3 2 a 7 3 a 8 a 3 a a and support with the aeromagnetic data. The revised and re-processed 5 a 15 2 from Paleo- to Neoarchean and geophysically and isotopically can be 5 2 a b 3

3

2 a 10 12,15 3 3 12,11 11,12 1 3 2 1 85°30' 85°00' 84°30' 84°00' 83°30' 2 1

3 Attawapiskat 7 a a a 227 m 2 7 1 7 linked to the Assean gneisses in Manitoba (Böhm et al. 2000) and the aeromagnetic dataset and derived products were provided by the 5 12,11 2 3 8 a 7 a 8 ! 23 a

2 11,12 a 69 m 11,12 1 12,11 Geological Survey of Canada through W. Myles (A/Section Head, 31 to 7 3 1 Tikkerutuk terrane (Alain Leclair, Geoscientist, Géologie Québec, a 2 2 11,12 a a 2 8 7 3 1 3 G-1447 3 34 m 11,12 a

2 7 5 a A a personal communication, 2006), which encompasses the 3.8 Ga Porpoise Radiation ). S. Josey provided digital cartographic support, a 15 tt 8 r WINISK aw 8 15 8 ive 1 a a 12,11 Att at R 7 2 pi a awapisk 3 0 updated and rectified the diamond-drill hole database compilation, and 12,11 sk Attawapiskat G-1446 a 6 10 Cove volcanic rocks on the western coast of Québec (David et al. 2002). at 3 2 R 1 a b ive 12,11 7 1 r 2 1 12,11 a 7 3 7 The Sachigo superterrane, with magmatic episodes from Meso- to assembled the final tables and base map. Several exploration companies 1 2 a 5 a 7 12,11 91A 12 5 a Neoarchean age, encompasses a core terrane, the North Caribou terrane, are thanked for their assistance in obtaining rock samples from the 1 11,12 12,11 1 a

a 7 7 2 r 114 m 1

e 2 2

7 3 3 a a iv 126 m b 3 15 3 a 3 R 2 3 2 Sachigo Subprovince and Hudson Bay Lowland, in particular, De Beers a at 2 1 and linear granite–greenstone domains on its south and north flanks that At pisk 7 a b a 12,11 2 tawa 3 1 a 7 3 11,12 2 a a a 3 15 60 2 1 3 1 1 record an outward growth through the Neoarchean. South of the Hudson Canada Exploration Inc., Wallbridge Mining Co. Ltd. and Spider Resources 2 b 7 a 2 53°15' 7 11 2 7 6 1 1 a 3 G-4244 a 3 a 7 5 c 23 11,12 a 2 Inc. 11,12 G-1252 a 12,11 a MACFAYDEN-2 Bay Lowland, major dextral transcurrent faults mark the boundaries 1 3

10 a 2 1 7 2 b KYLE-2 PROVINCIAL G-4245 2 a 17a 9 52 3 KYLE-3 7 1 1 10 3 1 between the two superterranes and between the Island Lake and Oxford– 20 m 1 3 7 55 12,11 2 La ! G-4225 a 7 12 a wa 7 ! UNNAMED a shi C l 27 5 7 a a 11,12 1 hanne a a G-3844 UNNAMED Stull domains (see Figure 1). Later, Proterozoic (circa 1822 Ma and 1100 References G-4304 1 6 1 2 0 7 7 12,11 a

G-4288 2 UNIFORM-1 6 a a a 1 3

3 12,11 53°00' b 3 7 Ma) carbonatitic complexes (Sage 1991, p.685) intruded close to these 1 2 2 2 a a 1 6 G-4305 12,11 11,12 5 12 8 5 7 GOLF-1 faults, implying subsequent post-Archean reactivation of these faults. Böhm, C.O., Heaman, L.M., Creaser, R.A. and Corkery, M.T. 2000. b 10 G-3845 7 54 a 12,11 KYLE-5 GOOD FRIDAY 30 281 m G-4184 1 1 ! Discovery of pre-3.5 Ga exotic crust at the northwestern Superior 10 5 7 264 m 7 ! 1 G-4194 a 5 12 1 7 a a 1 1 3 7 a 7 31 13 ver 7

G-4205 5 i 2 60 Province margin, Manitoba; Geology, v.28, p.75-78. 15 a a a 1 R a North Caribou Terrane 15 12 7 16 57,58 hi 1 3 a 1 s 7 306 m a 7 G-4287 2 0 aw 1 39 m 11,12 a L a MACFAYDEN-1 BRAVO-1 a 52 55 PARK 7 5 WI 3 N a G-3842 ! 15 11,12 G-4168 50 1 14 12,11 a ISK F 12,11 ! 2 1 AUL 7 3 T 1 2 220 to 299 m Böhm, C.O., Heaman, L.M., Stern, R.A., Corkery, M.T. and Creaser, R.A. 21 m 1 7 12,11 The central core of the North Caribou terrane (NCT) shows limited 7 7 1 a 2 VICTOR-1 11,12 3 a 7 a TA NGO-1 10 a 2 1 a a 18 2 7 2 12,11 G-4169 1 19 3 2003. Nature of Assean Lake ancient crust, Manitoba: a combined 3 11,12 7 a 3a Neoarchean magmatism, north of the Uchi-associated magmatic arc of a 0 11,12 a 54 a 1 U2 Kimberlite !! 12,11 2 a 7 53 25 15 21 1 ! 3 3 a b 11,12 !! ! AT-56 SHRIMP-ID-TIMS U-Pb geochronology and Sm-Nd isotope study; 7 11,12 2 1 TANGO EXTENSION ! late Neoarchean plutons, but it is dominated by Mesoarchean batholiths. a 3 ! 2 !! Garrioch G-4307 G-4190 47 m 7 17 51 2 a 53°00' 11,12 1 2 1 a 3 57,58 2 7 DELTA-1 7 1 3 U1 Kimberlite Precambrian Research, v.126, p.55-94. Lake G-4308 a 1 6 1 G-4211 G-4200 a a However, the Island Lake domain, like the Uchi domain to the south, 7 G-1253 7 a 7 1 c a 2 5 a a a 50 53°N 7 11,12 2 ! 6 2 ! 18 m a 4 3 2 ! ! 20 3 contains widespread evidence of Neoarchean magmatism and b 3 3 2 b 22 2 G-4286 a CHARLIE-1 ! G-0416 5 a ! 2 2 3 96 m a 1 ! a 3 1 1 1 11,12 2 3 ! 190 m 7 7 7 3 3 ! Bostock, H.H. 1971. Geological notes on Aquatuk River map-area, b 11 a a 5 2 7 11,12 a 53 ! 102 m 3 1 a 2 a sedimentation. A few remnants of 2.9 to 3.0 Ga supracrustal rocks are a a 3 11,12 3 7 a 51 46 m a 11,12 2 39 m 2 a ! Ontario with emphasis on the Precambrian rocks; Geological Survey 15 26 56 KYLE-4 DELTA-NORTH 52°45' preserved in the NCT, notably in the Red Lake and North Caribou Lake 11 G-4195 1 WHISKY G-4285 1 7 G-4183 ! 10 47 m 7 1 a 5 greenstone belts. Rift sequences of circa 2.9 Ga age occur locally in the of Canada, Paper 70-42, 57p. 51 m a 7 23 1 0 a 1 1 7 11,12 15 7 8 7 15,12 a X-RAY 23 to 24 2 ! 56 G-4206 a a central NCT containing 2.97 to 3.048 Ga detrital zircons and subsequent 53 m 1 3 41 m 29 m 7 b G-3879 ! a 5 1 G-1250 a 1 11 11 ALPHA-1N 7 3 7 1 Buchan, K.L. and Ernst, R.E. 2004. Diabase dike swarms and related 2 10 G-4226 a 2 ! marine volcanism. Two periods of plutonic and metamorphic activity a G-3852 7 11,12 ! 1 G-3872 11 3 YA NK EE -1 ! 7 1 a 5,8 a 5 a 2 1 7 15,12 27 units in Canada and adjacent ; Geological Survey of Canada, a 7 a 1 26 to G-4219 3 11,12 ALPHA-1 occur across the NCT at 2.89 to 2.895 Ga and 2.85 to 2.86 Ga. The NCT 0 G-4306 a 1 7 3 1 15 11 a 7 7 1 a 1 2 11 1 T1 Kimberlite 15 39 m 11,12 a a 5,8 7 7 7 ZULU-1 Map 2022A, scale 1:5 000 000, with accompanying notes. a 11 b forms a Mesoarchean core upon which subsequent Neoarchean crust G-4222 3 a a a 1 a 47 3 5,8 11,12 15,12 2 ! 7 2 X-RAY-1 ! G-5131 2 3 r 3 a 1 a 5,8 e has been added to the north and south margins and wraps around the 5 7 29 2 v a 26 to 3 i INDIA-1 Webequie a 1 11 OTOSKWIN- 2 191 m G-3873 1 28 5,8 R 7 G-4283 G-4284 44 m 7 11,12 Buchan, K.L., Harris, B.A., Ernst, R.E. and Hanes, J.A. 2003. Ar-Ar dating 11 a u a east side under the James Bay Lowland. a a

1 3 2 11 I.R. McFaulds G-4213 1 1 7 k 7 2 s 52°45' 10 11,12 1 5 3 a 1 i of the Pickle Crow diabase dike in the western Superior craton of the 7 a 1 11,12 Lake 1 a 8 7 7 p a 7 a a 5,8 a b b 12,11 5 a 3

Canadian Shield of Ontario and implications for a possible plume centre G-0248 12,11 19 m b K 2 3 a Island Lake Domain G-4188 G-3853 1 3 2 11,12

7 3 11 2 associated with ca. 1880 Ma Molson magmatism of Manitoba; in Annual 10 G-4196 a 1 2 12 0 AT TAWA PI S K AT 11,12 7 5,8 5 2 1 a b 1 7 Meeting of the Geological Association of Canada, Mineralogical 5 3 7 12 3 252 m a 1 11 The Island Lake domain is largely plutonic with some Mesoarchean to a a 2 1 15 1 7 1 b 10 11,12 2 1 8 7 1 5,8 ! 52°30' 7 7 7 a 7 3 Association of Canada, Society of Economic Geologists, Vancouver, 3 a a a a a 2 1 1 2 Neoarchean volcanic belts with geophysical characteristics that show a 2 5, 11,12 7 7 3 3 11 a 49 G-5129 G-4209 a G-3843 a Canada (published as CD and printed volume), p.17. 12 a a

10 3 G-3874 some relationship to the belts within the NCT. The boundaries of the 12 5,10 2 1

124 m 2 7 3 1 1 11,12 7 1 a 7 a 11,12 a 2 11,12 145 m 7 a 3 Island Lake domain are probably the least understood and remain the 15 86 m a a b 6 8 2 b 5,10 12 8 1 3 2 48 G-5130 5 a 7 Corfu, F. and Stott, G.M. 1993. U-Pb geochronology of the central Uchi 5 8 a a most contentious; modifications to the boundaries proposed by Parks et 5, 100 m 1 G-4201 3 a ! G-4282 2 7 3 a 2 1 Malloy 1 155 m 6 3 2 Subprovince, Superior Province; Canadian Journal of Earth Sciences, G-4281 10 a 1 1 7 1 10 49 2 7 c 7 5 7 a a 10 3 2 al. (2006) and Percival et al. (2006) are made in Figure 1 based partly 3 RIVER G-3855 a a a b Lake 2 6 1 3 3 3 7 2 2 a 5,10 c 2 1 v.30, p.1179-1196. a 3 11,12 1 152 m b 1 7 on geochronology and isotopic results of Rayner and Stott (2005) near 2 7 G-4280 5,10 7 3 a 11 a 2 a a 3 a G-4167 2 3 a 3 G-4212 a KYLE-1 the James Bay Lowland where the Island Lake domain appears to have a

2 2 10 5 3 5,10 3 2 ! Corkery, M.T., Cameron, H.D.M., Lin, S., Skulski, T., Whalen, J.B. and 11,12 52°30' ! incorporated some older crustal contaminants in contrast to the more 48 a 2 11,12 1 a

3 Stern, R.A. 2000. Geological investigations in the Knee Lake belt 100 m G-4186 133 m 7 3 2 a a 1 2 juvenile Oxford–Stull domain (Rayner and Stott 2005). 3 PROVINCIAL 1 b b 59 3 3 1

10 a 7

2 11,12 Franklin 7 8 7 3 3

a a a Scale 1:750 000 3 (parts of NTS 53L); in Report of Activities 2000, Manitoba Industry, 15 G-5127 G-4199 G-4217 3 a a 2 2

a 2 Lake a 2 7 1 a a 7 6 132 m G-4192 3 a 1 3 1 2 3 Trade and Mines, Manitoba Geological Survey, p.129-136. b 11,12 a c 7 7 15 2 3 2 b Oxford–Stull Domain 3 a a 2 11 3 11 2 1 11,12

G-4279 G-5128 7 a 2 3 85°30' 85°00' 84°30' 84°00' 5 PARK a a 1

12 5 2 7 2 G-3875 3 G-4185 2 a 3 2 G-4202 Pulham 15 11 2 David, J., Parent, M., Stevenson, R., Nadeau, P. and Godin, L. 2002. La 5 3 10 a 11 3 1 7 a At the northern margin of the Sachigo superterrane, the Oxford–Stull a Lake G-4276 10 11,12 a b 11 1 5 3 Figure 2. Close-up of the Attawapiskat cluster of kimberlite pipes on an aeromagnetic image that also highlights Proterozoic mafic (diabase) dikes. The close, linear séquence supracrustale de Porpoise Cove, région d'Inukjuak : un b 2 G-4280 11,12 2 5 2 domain (OSD) stretches from Manitoba to the James Bay Lowland 11 3 5 3 6 3 134 m 130 to 132m 3 2 b 1 proximity of most of the kimberlite pipes to one of the Matachewan dikes is most apparent. (See “Legend” for rock types and symbols.) exemple unique de croûte paléo-archéenne (ca 3.8 Ga) dans la a a 7 1 (see Figure 1). In Manitoba, the OSD has been best studied in the a 11 Province du Supérieur; Ministère des Ressources naturelles, Québec, 147 m Oxford Lake–Knee Lake area where it includes several assemblages 10 14 b 59 3 2 3 1 DV2002-10, p.17. 10 2 3 12 3 a 23b G-4207 7a 11,12 G-4148 (ages are compiled in Manitoba Geological Survey 2005) ranging in age a 11,12 b b 23 G-4189 3 G-4147 2 from Mesoarchean (2870 to 2830 Ma) to Neoarchean volcanism at 2722 Kitchie 1 23b 2 7 3 DePaolo, D.J. 1981. Crustal growth and mantle evolution: inferences from 15 a 8 15 G-5126 a a Ma and detrital zircons in overlying sediments as young as 2707 Ma 2 Lake 1 3 UTM Zone 15 UTM Zone 16 UTM Zone 17 3 7 2 models of element transport and Nd and Sr isotopes; Geochimica et a a G-5116 15 (Corkery et al. 2000). Across the breadth of the OSD, there is a 11 52°N 10 b 11,12 2 15,11 Cosmochimica Acta, v.44, p.1185-1196. 3 6 predominance of Neoarchean U/Pb zircon ages derived through sensitive 10 2 b 54B 2 54A 44D Benjamin Lake 12 3 high-resolution ion microprobe (SHRIMP) analyses of volcanic and G-4274 a Geological Survey of Canada 2003. Canadian aeromagnetic data base; b plutonic rocks near the Manitoba–Ontario border (as young as 2710 Ma) G-3176 3 53N Regional Geophysics Section, Geological Survey of Canada, Earth G-4265 11,12 2 53O 53P 43M 43N 43O and farther east near the James Bay Lowland in Ontario (2737 to 2696 Ma). 5 8,10 10 Sciences Sector, Natural Resources Canada. 11 53K Neoarchean to Mesoarchean Nd model ages with negative εNd values 12 53J 53I 43L are consistent with relatively juvenile crustal growth (Skulski et al. 2000; 5 43K 43J Halls, H.C., Stott, G.M. and Davis, D.W. 2005. Paleomagnetism, Rayner and Stott 2005). The OSD displays some evidence of geochronology and geochemistry of several Proterozoic mafic dike Mesoarchean mid-ocean ridge basalt (MORB)-like sequences concurrent 53F 53G 53H 43E 43F 43G 43H swarms in ; Ontario Geological Survey, Open with continental magmatic growth within Northern Superior superterrane File Report 6171, 75p. and NCT margins to the north and south, respectively. The southern 50° 43D 43A 43C 43B contact of the OSD with the Island Lake domain of the NCT shows a Halls, H.C., Davis, D.W., Stott, G.M., Ernst, R.E. and Hamilton, M.A. 2008. prevalence of Mesoarchean zircon ages and isotopic evidence for a The Paleoproterozoic Marathon Large Igneous Province: new 42M 42N 42O 42P 32M shared constructive history with the OSD across the Stull–Wunnummin evidence for a 2.1 Ga long-lived mantle plume event along the fault. southern margin of the North American Superior Province; Precambrian 42I 32L 87°W 86°W 85°W 84°W 83°W 82°W 42L 42K 42J Research, v.162, p.327-353. 32E 42E 42F 42G 42H Heaman, L.M. and Kjarsgaard, B.A. 2000. Timing of eastern North 90° 84° American kimberlite magmatism: continental extension of the Great Meteor hotspot track?; Earth and Planetary Science Letters, v.178, Index to location of UTM zones and 1:250 000 scale NTS sheets. p.253-268.