Uranium Deposits of Ontario- Their Distribution and Classification

Home , Elliot Lake, Geology of Ontario, Kirkland Lake, Milliken Mine, Pronto Mine

Ontario Geological Survey Miscellaneous Paper 86

The Uranium Deposits of Ontario- Their Distribution and Classification

By James A. Robertson

1981

lanWPope Ministry of !^st£ Natural ...__ W.T. Foster Deputy Minister Ontario ®OMNR-OGS 1981 ISSN 0704-2752 Printed in Canada ISBN 0-7743-602627

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Parts of this publication may be quoted if credit is given. It is recommended that reference to this report be made in the following form: Robertson, James A. 1981: The Uranium Deposits ol Ontario-Their Distribution and Classifica- tion; Ontario Geological Survey Miscellaneous Paper 86,37p.

1000-300-80-MP ii Contents Abstract v Introduction 1 Geology of Ontario 2 Uranium Deposits of Ontario 2 Superior Province 2 Northwestern Ontario 2 AikalicVolcanics, Kirkland Lake Area 6 Southern Province 6 Elliot Lake Area 8 Ore Mineralogy 14 Agnew Lake Area 16 Cobalt Embayment 17 Genesisofthe Elliot Lake Pyritic Quartz-Pebble Uranium Deposits 17 Grenvilte Province 20 Red Zoned Pegmatite 22 Red Unzoned Pegmatite 22 Calc-Silicate Deposits 23 Hydrothermal Vein Deposits 23 Lake Superior Basin 25 Thunder Bay Area 25 Montreal River Area 26 Alkalic Complexes 28 Phanerozoic Deposits 29 March Township 29 Conclusions 30 Acknowledgments 32 Appendix 32 References 33

Tabtes

Table 1—Uranium resources, World, Canada, Ontario (1977) 1 Table 2—Systems of Huronlan Stratigraphio Nomenclature 10 Table 3—Summary of Huronian Stratigraphy in the Blind River-Elliot Lake Area 11 Table 4—Correlation of Quartz-Pebble Conglomerate Reefs, Ouirke Zone 15 Table 5—Uranium, thorium, and titanium contents of Blind River Brannerite 16 Table 6—Uranium and thorium contents in Blind River uraninite 17 Table 7—Analyses of Blind River monazites 17 Table 8—Uranium deposits of the Bancroft District 22 Table 9—Classification of uranium deposits in Ontario 31 Table 10—Uranium resources, World, Canada, Ontario (1979) 32

Figures

figure 1—Geology of Ontario 3 Figure 2—Principal uranium deposits of Ontario 4 Figure 3—Uranium deposits Kenora-Dryden Area 5 Figure 4—Hawk Lake Showing, MacNicol Township. District of Kenora 7 figure 5—Uranium distribution in the Blind River Area 9 Figure 6—Uranium deposits in the QuirkeSyncline-Elliot Lake Area 12 figure 7a—Cross Section-New Quirke Mine 13 Figure 7b—Shaft Section-Agnew Lake Mines Limited 14 figure 8—Uranium deposits-Cobalt Embayment and Agnew Lake Areas 18 figure 9—Uranium deposits -Bancroft Area 21 Figure 10—Plan of 450 foot Level-Faraday (Madawaska) Mine 24 Figure 11—Uranium Deposits in the Greenwich Lake Area 25 Figure 12—Camray Deposit, Theano Point, Lake Superior, Slater (Township 29, Range 14) District of Algoma 27 Figure 13a—Manitou Islands Complex 29 Figure 13b—Prairie Lake Complex 30

iii Conversion Factors for Measurements in Ontario Geological Survey Publications If the reader wishes to convert imperial units to SI (metric) units or SI units to imperial units the following multipliers should be used:

CONVERSION FROM SITO IMPERIAL CONVERSION FROM IMPERIAL TO SI SI Unit Multiplied by Gives Imperial Unit Multiplied by Gives LENGTH imm 0.03937 Inches linen 25.4 mm 1 cm 0.39370 inches linen 2.54 cm 1m 3.28084 feet Hoot 0.3048 m 1m 0.0497097 chains 1 chain 20.1168 m 1km 0.621371 miles (statute) 1 mile (statute) 1.609344 km AREA 1cm2 0.1550 square inches 1 square inch 6.4516 cm* 1 m* 10.7639 square feet 1 square foot 0.09290304 m* 1km2 0.38610 square miles 1 square mile 2.589988 km2 1 ha 2.471054 acres 1acre 0.4046856 ha VOLUME 1 cm' 0.061 02 cubic inches 1 cubic inch 16.397064 err? 1m3 35.3147 cubic feet 1 cubic foot 0.02831685 rri> 1m3 1.3080 cubic yards 1 cubic yard 0.764555 ni> 1L 1.759755 pints 1 pint 0.568261 L 1L 0.879877 quarts 1 quart 1.136522 L 1L 0.219969 gallons 1 gallon 4.546090 L MASS 10 0.03527396 ounces (avdp) 1 ounce(avdp) 28.349523 0 10 0.032150 75 ounces (troy) 1 ounce (troy) 31.1034769 1kg 2.20462 pounds (avdp) 1 pound(avdp) 046369237 *g 1kg 0.0011023 tons (short) 1 ton (short) 907.19474 kg 11 1.102311 tons (short) 1 ton (short) 0J0719474 1kg 0.00098421 tons (long) 1 ton (long) 1016.0469099 kg 0.9842065 tons (long) 1 ton (long) 1.0160469096 t CONCENTRATION 1g/t 0.0291866 ounce (troy)/ 1 ounce (troy)/ 34.285714 2 ton (short) ton (short) 1 g/t 0.58333333 pennyweights/ 1 pennyweight/ 1.7142657 gn. ton (short) ton (short) OTHER USEFUL CONVERSION FACTORS 1 ounce (troyKon (short) 20.0 pennyweights/ton (short) 1 pennyweight/ton (short) 0.05 ounce (troy)/lon (short)

NOTE—Conversion factors which are in bold type are exact. The conversion factors have been taken from or have been derived from factors given in the Metric Practice Guide for the Canadian Mining and Metallurgical Industries published by The Mining Association of Canada in cooperation with the Coal Association of Canada.

CONVERSION FACTORS FOR URANIUM

1 short ton U3O3 x 0.76931 -1 ton U 1 tonne U X 129987-1 ihort ton U3Oa U3O8 Ib/short ton x 0.42401- Ukj/tonn. Ukg/tonne x 235844- U3O8 Ib/short ton Not*: These conversion factors are ussd by the Canada Centre for Metal Extraction Tech- nology, Mineral Research Laboratory.

IV Abstract

The geology of Ontario comprises Precambrian and Phanerozoic rocks. The Precambrian (Canadian Shield) is subdivided into Provinces and Subprovinces based on stratigraphy and structure. The principal types of uranium deposits in Ontario are: 1) carbonatites and fenites (Prairie Lake); 2) alkalic volcanic rocks (Kirkland Lake); 3) pegmatites (Bancroft and Kenora-Dryden); 4) calc-silicate rocks (Ban- croft); 5) pyritic quartz-pebble conglomerates (Blind River, Southern Province); 6) polymictic conglomerates and some pelitic rocks (Cobalt Embayment Southern Province); and 7) various "pitchblende" deposits including:a) Late Precambrian unconformities (Thunder Bay); b) possibly Late Pre- cambrian diabase dikes (Montreal River); c) other unconformities: i) carbonates (March Township); ii) sandstones (James Bay Lowlands); iii) lignites (James Bay Lowlands); iv) semi-pelitic rocks of Middle and Upper Precambrian age (Cobalt Embayment and Thunder Bay). Only red unzoned pegmatite (Bancroft) and the pyritic quartz-pebble conglomerate (Elliot Lake and Agnew Lake) have supported production. White pegmatites, alkalic complexes, calc-silicates, and unconformity related deposits have attracted considerable exploration activity. Ontario reasonably assured and estimated resources in the economic and subeconomic categories In 1977 amounted to 553 000 Tonnes recoverable U and 1977 production amounted to 4000 Ton- nes U. Measured, indicated, and inferred resources in the Elliot Lake-Agnew Lake area are at least 400 000 Tonnes recoverable U. The latter deposits are also a significant thorium resource. Geological features reflecting major changes in physics and chemistry are prime controls on distribution of uranium deposits. Geological province and subprovince boundaries (including unconformities), major faults, higher metamorphic grades, domain boundaries related to quartz monzonite batholiths, alkalic complexes, and the distribution of carbonate rocks are examples of such geological features. For each deposit type, a systems analysis identifies parameters critical to 1) source area; 2) transportation; 3) deposition; 4) modification; and 5) preservation, to which could be added 6) extraction. These parameters can then be used to identify areas of high exploration potential and to attempt predictable resource evaluation. THE URANIUM DEPOSITS OF ONTARIO - THEIR DISTRIBUTION AND CLASSIFICATION

James A. Robertson1

The Ontario Geological Survey uses the term deposit Introduction as a general term including producers, past producers, prospects, and occurrences. Thus, the term carries no The purpose of this paper is to briefly review the geology implication as to resources or grade. of Ontario, to summarize the nature and distribution of the Those readers who are interested in the systematics uranium deposits in Ontario, and to provide a selected of uranium mineralogy are referred to papers by; R.O. bibliography. An earlier version of this paper (Robertson Morton (1978) and H.R. Steacy andS.S. Kaiman (1978) in 1978b) was prepared in July 1978 as a contribution to the M.M. Kimbertey (1978), E.W. Heinrich (1958), and the Short Course in "Uranium Deposits: Their Mineralogy and Colorado School of Mines, Research Institute (1976). Origin" sponsored by the Mineralogical Association in The author's main experience has been with the Elliot Toronto, and was included in the short course handbook Lake Camp, and a major part of this discussion concerns (Kimberley 1978). Since the original paper was prepared, that camp and its geological setting. N.J. Theis (1978a) in several significant publications relevant to the uranium Kimberley (1978), discussed in more detail the implica- deposits of Ontario have been published. Only minor tions of recent research on the mineralogy and sedimen- changes and clarifications have been made to the text, tation of the Elliot Lake Deposits. but the list of references has been expanded. The Province of Ontario comprises 10» km2 and stretches trom the Great Lakes northwards to James Bay and Hudson Bay between Manitoba and Quebec. Within that area, there is a wide variety of geological environ- 1 Chief, Mineral Deposits Section, Ontario Geological Survey. ments with rock units ranging in age from Early Precam- Toronto. brian to Cretaceous. The province hosts two uranium Manuscript approved for publication by E.G. Pye, Director, On- mining camps - the Blind River-Elliot Lake-Agnew Lake tario Geological Survey, 2nd May, 1980. camp and the Bancroft camp. Table 1 summarizes data

TABLE 1 URANIUM RESOURCES (1977) 1000TONNES U.

Reasonably Assured Estimated Additional $/kgU Measured Indicated Inferred Prognosticated WORLD COST <80 16501 1S1O3 80-130 540 590 <130 2190 42902 2100 CANADA PRICE <104 79 167 88 238 392 104-156 4 15 11 67 264 <156 S3 182 99 838 30'f 656 349 ONTARIO PRICE (197S) <156 49 125 76 553 246 428 182 Footnotes 1 Column indicates reasonably assured resources. 2 Column indicates total uranium resources. 3 Column indicates estimated additional resources. Uranium Deposits of Ontario

published in 1977 on World, Canadian, and Ontario Ura- nulite, and by alkalic intrusives 100 my to 1000 my in age nium resources. Data published in 1978 shows a slight in- which are located near the boundary faults. crease in the resources in Ontario, but as new discover- The Southern Province (K.D. Card el al. 1972) is ies continue to be made and evaluated in Australia and in characterized by Proterozoic sedimentary rocks. In the Saskatchewan and Western Canada, the Ontario share of Lake Huron area, the Huronian Supergroup is divided both the world and Canadian resources is in declira (En- into four groups, the lowermost of which hosts the Elliot ergy, Mines, and Resources 1977,1978a, and 1978b; Or- Lake uranium deposits and minor mafic volcanic rocks ganization for Economic-Cooperation and Development (Bennett 1978; J.A. Robertson 1969, 1976; Roscoe 1977; Porter 1978; and J.A. Robertson 1978a and 1969). The Grenville Province (Wynne Edwards 1972) is 1978b). exposed in central and eastern Ontario. The last major Using the 1977' publications, the latest permitting deformation and metamorphism of the Grenville Province worldwide comparison, Ontario had 76 percent of Cana- took place at 950 my. The northwestern part comprises da's measured, indicated, and inferred resource, (Ener- largely granitic rocks (Ayres ef al. 1970) that were origi- gy, Mines, and Resources 1977), 52 percent of the prog- nally Lower Proterozoic sedimentary rocks. The south- nosticated resources, and 13 percent of the free world's eastern part of the Grenville Province is a younger com- reasonably assured and estimated additional resources plex, the Grenville Supergroup, which is composed of [See appendix for update]. Ontario's estimated 1977 pro- metavolcanics, marble, other metasediments, and a vari- duction was 4000 tonnes U, but this includes material ety of intrusive rocks. The base of the Grenville Super- from stockpiles which was considerably greater than the group passes close to Bancroft. The pegmatite and calc- previous year. A marked expansion of productive capac- silicate uranium deposits of the Bancroft area lie within ity is taking place. The 1977 production constituted ap- the Grenville .Supergroup and close to its base. This proximately 66 percent of Canada's production, and 14 boundary is currently interpreted to be an unconformity in percent of the world's production (not including the cen- the Upper Precambrian (Gordon and Masson 1977, trally governed nations). J.A. Robertson estimated that 1978; Lumbers 1975, Bright 1975, 1976, and 1977). An the measured, indicated, and inferred resources of the outlier of Upper Precambrian mafic volcanic rocks occurs Elliot Lake-Agnew Lake area Huronian rocks are at least at Parry Sound. 400 000 tonnes recoverable U and Roscoe has placed Phanerpzoic rocks lie unconformably on Precam- the entire resources of the Huronian environment at 500 brian rocks in southwestern Ontario, eastern Ontario, and 000 tonnes U (J.A. Robertson 1975,1976, and 1978a). in the James Bay Lowlands.

Geology of Ontario Uranium Deposits of Ontario Ontario (Figure 1) is principally underlain by Precambrian rocks of the Canadian Shield. In eastern Ontario and Superior Province southwestern Ontario, the Precambrian rocks are overlain Northwestern Ontario by flat-lying Paleozoic sedimentary rocks. In the north, the Hudson Bay Lowland includes Paleozoic and Meso- zoic rocks. The Canadian Shield is subdivided on the ba- The best known Early Precambrian uraniferous pegmatite sis of lithotogy and structural history into provinces and occurrences are in the Wabigoon Subprovince of the Su- subprovinces (Stockwell 1964). Within Ontario, there are perior Province in the Kenora-Dryden area at Vermilion three provinces (L.D. Ayres ef al. 1970a,b,c,d, and e): the Bay (4)2 and in the English River Gneiss Belt (2,3); (Rob- Superior Province, the Southern Province, and the Gren- ertson 1968a, 1976; Beard and Rivett 1977, 1978). Ex- ville Province. The Superior Province comprises Early ploratory work has also been undertaken at Greenwich Precambrian rocks last deformed during the Kenoran Or- Lake (5) and Favourable Lake (1), (Berens River Subpro- ogeny (2600 my). This province contains easterly-trend- vince), (Figures 2 and 3). ing zones which are dominantly composed of metavol- These deposits bear a strong resemblance to some canics and metasediments interspersed with granitic of the deposits of the MacTier (16) and Bancroft (III), Ka- rocks. Subprovinces of the Superior Province (Figure 2) tadar-Sharbot Lake (18) areas and comparison with the are distinguished on the basis of dominance of rock type, Rossing deposit of Namibia (Beming et al. 1976) has also and the boundaries between the subprovinces are locally been made. The Ontario pegmatite bodies lack a well-de- transitional rather than sharply defined tectontcally, meta- veloped zone of secondary enrichment. Radioactivity morphically, or geophysically. The east-west grain is in- was first discovered at Willard Lake some 56 km east of terrupted by ihe Kapuskasing Structure, a horst block Kenora in 1949, and E.O. Chisholm (1950) reported a which trends northeast from Lake Superior to James Bay, cluster of radioactive grey and red pegmatite bodies lo- is characterized by a gravity high, the presence of gra- cated between Willard Lake and Bee Lake (4) near the Trans-Canada Highway. These exhibit a yellow stain and 1 Since this was written, further publications (1979) have be- 2 The number(s) in parentheses indicates deposit location on come available, sec Appendix and Table 10. Figure 2. 100 200 Kilometres

LEGEND

Phanerozoic 4 Sediments 3 Metasediments LJ Superior Province 2 Metavolcanics 1 Granitic Rocks Southern Province • Ottawa-Bonnechere Graben Grenville Province b Kapuskasing Horn

Unclassified • Alkaltc Complexes

Figure 1—Geology of Ontario. ss° URANIUM DEPOSITS

Favourable L. English River North English Rivar Cantral Drydan Thunder Bay. Greenwich L. BamajiL. Prairie L. Colowell Ganldton FJretand L. Montreal R. Chepiaau Kiikiand L. Cobalt Embayment (Conglomerate ± Samtpelite) tfogama Lake Nlptalng Maetier-farry Sound March Tp. Kaladaf-Sharbot L. Jamas Bay Lowlands

LEGEND TYPE OF DEPOSIT

^J Paleozoic & Meaozoic I Alkalic Complexet PRECAMBRIAN ] Pegmatitic I I Superior Province Cilc Silicate ill Southern Province Veins P73 Grenville Province b Late Precarnbrian | Conglomerate M UncltJtifMid a Middle Precambriao ] Other

Figure 2—Principal uranium deposits of Ontario. GENERAL GEOLOGY OF ENGLISH RIVER SUBPROVINCE AND PARTS OF UCHI AND

WABIGOON SUBPROVINCES

I;; 11 • •[ Metinds & Derived MigmMite

^^^^| Metavolcanics

^^^fl Gntinic Granitoid Suite

I ~J Mafic Plutonic Suite

| | Sodic Plutonic Suite

Potawc Plutonic Suite

URANIUM DEPOSITS

. Associated With A I Meusedlmentary ' Migmatite Environment

Associated With 0 I Potassic Granitoid ' Suite Rocks

40 km

Figure 3—Uranium deposits in Kenora-Dryden area, after F.W. Breaks and VV.D. Bond (1978). Uranium Deposits of Ontario

contain magnetite, biotite, and scattered molybdenite. metamorphic minerals such as sillimanite and garnet, The best showings were found at the west end of the belt and is associated with the Sydney Lake Cataclastic Zone where pegmatite intrudes mafic metavolcanics. Two of [Zf (Beard and Rivett 1978) and the interdomain bound- these intrusive bodies, the Hawk Lake and the Richard ary (3), whereas Type 2 pegmatite occurs in the Separa- Lake showings, were described by J. Satterly (1955) who tion Lake (3) area and may be compared with the western emphasized the intimate association of uranium with Vermilion Bay deposits (4). The Favourable Lake-Bear- magnetite (see Figure 4). head area (1) is also worthy of mention. Here, pegmatite The Richard Lake Deposit was explored by two adits occurs in a narrow migmatitic zone at the boundary of a and has been estimated to contain reserves of 650 000 radioactive quartz monzonite and carries uraninite, allan- tons, grading 0.10 percent U3O8 over a length of 210 m, a ite, and molybdenite; near surface fractures are coated depth of 300 m, and a width of 3 m. This is the only de- with uranophane. The zone lies at the margin of the Ber- posit in Northwestern Ontario for which such data are ens River Block (Ayres 1970). available (J.A. Robertson 1968a). To the east, pegmatite A similar showing occurs west of Sioux Lookout at bodies occur in mafic volcanic rocks, intermediate vol- Bluett Lake in Drope Township (J.A. Robertson 1977). canic rocks, metasediments, and quartz monzonite. This is described in the Mineral Deposits Files in the Re- These are diffuse and erratic both in distribution and min- gional Geologist's Office at Kenora, and in the Resident eralization. Although local grades may be encouraging, Geologist's Office at Sioux Lookout. A uranium showing for example 0.5 to 1.5 lbs per ton, with occasional grab near Bamaji Lake (6), 160 km east of Red Lake is located samples of 10 lbs per ton (0.5 percent) U3Oe or more, it on a possible porphyry dike near a molybdenum-bearing has not proven possible to establish significant tonnage porphyry stock. However, the rock is strongly sheared over mining widths carrying in excess of 0.5 Ib (0.025 and uranium mineralization occurs with calcite, dolomite, percent) U3(Vton. The area was remapped by A.P. Prys- actinolite, and pyrite (Breaks et al. 1978; Sage and lak (1976) whose report coincided with renewed interest Breaks 1976; J.A. Robertson 1977; and Wallace 1978. in uranium. Field notes and radiometric or assay data are Field examination suggests that the "quartz porphyry" on file in the Regional Geologist's Files, Ontario Ministry may be a sheared crystal tuff. In general, the boundaries of Natural Resources, Kenora, for some 20 showings of Ine granitic subprovinces and the boundaries of the (Scott 1976; Beard 197?, and R. Beard, Regional Geolo- granitic domains within subprovinces have been favoura- gist, Kenora, personal communication). ble sites for the redistribution, concentration, and redepo- During 1976-1977, V. RuiicK? R. Beara. and J.A. sition of uranium. Robertson confirmed the relationships described by ear- Further gamma-ray spectrometry, ground follow-up, lier workers in a visit to the Hawk Lake-Richard Lake area. regional mapping, and prospecting may identify other V. Ruzicka (personal communication) has ohown that ur- such areas in the Superior Province of Ontario. Results of aninite commonly occurs as inclusions in magnetite at such work are documented in annual reports of the On- both of these localities, including the Petursson Lake tario Geological Survey and the Geological Survey of showing. The most highly radioactive areas are biotite- Canada. Although uranium-concentrating processes rich or hornblende-rich zones in psgmatite, the colour of have not operated effectively enough to create viable ore which ranges from white through pink to red, depending deposits in most of the foregoing cases, such mineralized on the assimilation of mafic material and the extent of ne- areas are of further interest in that they may have been matization. The boundaries range from diffuse to sharp the source for deposits of other types located in nearby depending on the composition and the competency of younger rocks or structures. wall rock. The favourable zone is located along the con- tar* between a metavotaanic-metasedimentary belt and Alkalk Volcanic Rock* in (he Xirkland Lake Ana massive quartz monzonite. Alteration minerals have been An association of radioactive mineralization with alkalic identified as uranophane and p-uranotite. Blue-green volcanic recks has recently been recognized, but little apatite, molybdenite, and rarely garnet may also be pres- publicized, in the Kirkland Lake area (12) of the Abitibi ent. F>eld indications for mineralization include clots of Subprovince. Early descriptions (circa 1968) of these oc- mafic minerals, magnetite, molybdenite, apatite, yellow currences were sketchy and the host rocks were vari- stain, hematite stain, and smoky quartz. ously described as pegmatite, syenite-trachyte, grey- Uranium deposits also occur within the English River wacke, or greywacke-tuff (J.A. Robertson 1968a, 1975; Gneiss Belt (Beard 1977; Beard and Rivett 1978; Breaks Resident Geologist's Files, Ontario Ministry of Natural Re- et al. 1978; Breaks and Bond 1978). F.W. Breaks et al. sources, Kirkland Lake). These occurrences have been (1978) divided the English River Gneiss Belt into a north- visited by J.A. Robertson (the author), Ruzicka ern, predominantly metasedimentary domain and a (1977b,1978), and H.L Lovell and F.R. Ploeger (1977). southern, predominantly plutonic domain, and have clas- They have determined that the radioactivity is due to ura- sified the pegmatite as Type 1 (metasedimentary host nium associated with trachyte and trachytic tuffaceous rocks) and Type 2 (potassfc-plutonic-granitoid host greywacke. Mineralization was also noted in a conglom- rocks), in describing the domains and mineralization pro- erate bed associated with these rocks in Lebel Township. cesses, Breaks et a/. (1978) use modern European no- Scintillometer readings indicated a general level of radio- menclature. Type 1 is "white" pegmatite which carries activity of three to five times background, with locally

1 The numbers in pureni'nesss pertain to Figure 2 on page 4. 2 Refers to location shown on figure 2. LEGEND

Pugmatii? magnetite rich

Hornblende schist

Trench

Stripping 1954

/W3O8 Ch«nU308

0.09 0.10 0.0S 0.07 0.06 0.08 0.10 0.(9 0.12 0.21 0.23

SCALE

10 m

Figure 4—Hawk Lake showing, MacNicol Township, District of Kenora, after J. Satterly and Carlson (1954) in Satterly (1955). Uranium Deposits of Ontario

higher values. Assays have ranged from 100 ppm U to Late Precambrian olivine diabase (Figure 5). Table 2 0.1 percent U3O6. Drilling by Rio Algom Mines at the allows comparison of the stratigraphic nomenclature rec- Crystal Kirkland Occurrence revealed only one 0.9 m ommended by the Federal Provincial Committee on Huro- long section assaying 1 Ib U3O8 per ton. A surface chip nian Stratigraphy (J.A. Robertson et a/. 1969) to be made sample yielded 2 Ib U3O8 per ton across 1.5 m (Lovell with nomenclatures used in publications before 1969. Ta- and Ploeger 1977). ble 3 provides a synopsis of the stratigraphy and its rela- The Bidgood Kirkland Lake Mine occurs 8 km east of tionship to mineralization. Uranium ore in the Blind River- Kirkland Lake and approximately 1.5 km west of the Crys- Elliot Lake area only occurs within the Matinenda Forma- tal Lake Occurrence. At this mine, rocks resemble those tion. at Crystal Lake, and radioactivity has been observed over In the Elliot Lake-Blind River area, the Huronian Su- a width of 90 m and a strike length of 360 m (Lovell and pergroup has been gently folded into westward-plunging Ploeger 1977). In 1978, Messrs. Ruzicka, Robertson, and folds, and the metamorphic grade is low. To the south Lovell (J.A. Robertson 1978a) recorded anomalous radio- and east, folding is severe and the metamorphic grade activity in tuffaceous greywacke along the Ontario North- reaches the amphibolite facies; post-Huronian granite land Railroad, 1.5 km west of the Macassa Goldmine at occurs locally (Card et a/. 1972; J.A. Robertson 1967, Chaput Hughes, 3.2 km west of Kirkland Lake, and else- 1968a, 1968b, 1969,1970. 1975,1976,1977, 1978a, and where in the Kirkland Lake Belt. The nature of this ura- 1978b). nium mineralization is not !;nown. The uranium is proba- Basement structure was a major physical control on bly syngenetic with associated trachyte and syenite, and the deposition of Lower Huronian sediments and on their some of the uranium was transported in solution and de- enclosed uranium deposits (Figure 6). The lack of gold in posited within the tuffaceous greywacke and polymictic the uraniferous conglomerate is attributed to the general conglomerate. The grade appears to be sub-economic; lack of "greenstone" in the cratonic block north of the Hu- the grade was estimated by gamma-ray spectrometpy to ronian contact and to the low frequency of gold occur- be 0.25 Ib U3Oe/ton. The occurrences are worthy of fur- rences in the area believed to have been the source area. ther study as they represent known volcanic deposits in The Lower Precambrian in the Blind River-Elliot Lake the Lower Precambrisn of Ontario. Similar, but younger area has been subdivided into: Keewatin-type metavol- deposits have been reported in Yugoslavia, Greece, and canics and metasediments, including minor cherty iron Italy (Organization for Economic Co-operation and Devel- formations; pink to grey gneissic granitic rocks with abun- opment 1977). dant inclusions of Keewatin-type rocks; and massive, moderately radioactive, red quartz monzonite. The massive red quartz monzonite has been recorded from a Southern Province number of localities (J.A. Robertson 1976), and airborne gamma-ray spectrometry has confirmed that much of the Elliot Lake Area terrain north and northwest of the Elliot Lake area con- Blind River I [Area 1 on Figure 2 identified as Elliot Lake] tains anomalous amounts of uranium (Darnley and Grasty lies on the North Shore of Lake Huron, halfway between 1971; Richardson et al. 1975). Figure 5 shows the general Sudbury and Sault Ste. Marie, and the town of Elliot Lake correlation between anomalous uranium content and red lies 30 km northeast of Blind River. The following descrip- quartz monzonite (red granite on Figure 5). tion of the Blind River-Elliot Lake uranium camp is sum- The author believes that these massive red quartz marized from the author's earlier publications, particularly monzonite bodies and related pegmatite (now eroded) J.A. Robertson (1968b, 1969, and 1976). This region lies were the source material for the Elliot Lake deposits. Al- on the boundary between the Southern and Superior ternatively, J.P. McDowell (1957,p.35) proposed that the Provinces of the Canadian Shield. The Superior Province source area lay 210 to 400 km west-northwest of Thes- (Goodwin et al. 1972) comprises Archean rocks which salon in the Montreal River-Lake Superior area which is were affected by the Kenoran Orogeny (2600 my). The characterized by low-grade uraniferous pegmatite and Southern Province (Card et al. 1972) includes Proterozoic Late Precambrian pitchblende occurrences. sedimentary intrusive, and minor extrusive rocks affected After the Early Precambrian (Kenoran) orogenesis, by the Penokean Orogeny (1750 my). The Blind River-El- the area was deeply eroded and topography was con- liot Lake area lies at the northern margin of early Protero- trolled by basement lithology and structure. A regolith zoic sedimentation and of mid-Proterozoic metamor- (granite wash) developed; D.S. Robertson (1974), J.A. phism. Uranium and/or thorium mineralization is found in Robertson (1967,1968a, 1968b, 1969,1970,1975,1977, near-shore fluviatile rocks throughout the Southern Prov- 1978a, and 1978b), P.J. Pienaar(1963), and S.M. Roscoe ince (J.A. Robertson 1968a, 1976; Thomson 1960). (1969) have shown that this formed under reducing con- There are three major lithologic units in the Blind ditions. Many authors, for example Roscoe (1969, 1973) River-Elliot Lake area: 1) Archean basement, consisting and D.S. Robertson (1974), have suggested that this im- of Keewatin-type "greenstone", Algoman granite, and mi- plies a reducing atmosphere. Similar conditions else- nor mafic intrusive rocks; 2) Huronian sedimentary rocks where in the world at the Archean-Proterozoic boundary and metasediments, locally with minor mafic volcanic are similarly considered to suggest a reducing atmo- rocks; and 3) Post-Huror,ian intrusive rocks, comprising sphere which presumably provided a chronological con- the Nipissing Diabase sills, post-Nipissing Diabase trol on the Blind Riv9r type of uranium deposits (Roscoe Dikes, the Cutler Granite, the Croker Island Complex, and 1973; Smith 1974). Recently, E. Dimroth and M.M. Kim-

8 47 n

46°N

0 10 20 miles CM Scale I r-H H « 0 10 20 30 km

URANIUM p.p.m. GEOLOGY

C1 Post Huronian Granite

1 -2 Huronian Supergroup

-3 Pre Huronian j • Red Granite » -4

Grey Granite, Metavolcanics, >4 Metasediments.

Figures—Uranium distribution in the Blind River area. Airborne gamma-ray spectrometry is after K.A. Richardson, P.G. Kilieen, and R.W. Charbonneau (1974). TABLE 21 SYSTEMS OF HURONIAN STRATIGRAPHIC NOMENCLATURE.

COLLINS 1325 ROBERTSON 1967 ROSCOE 1960 ROBERTSON etal. 1969

Upper White Q.1 Bar River Upper White Q. Bar River Banded Cherty Gordon Lake Banded Cherty a Gordon Lake Lorrain Lorrain Lorrain Lorrain Gowganda Gowganda Gowganda 1 Gowganda Serpent Serpent Serpent Serpent Espanola Espanola Espanola Espanola Bruce Bruce Bruce Bruce Upper Mississagi Mississagi Mississagi Mississagi Middle Mississagi Argillite Pecors Pecors Conglomerate Whiskey Ramsay Lake (Ramsay Lake) Granites Lower Mississagi Argillite ** a. Nordic McKim McKim Quamite Matinenda Matinenda Archean Algoman Archean Archean Schist Complex Keewatin

Q = Quartzite 2 Volcanic rocks are found locally in the Elliot Lake Group.

berley (1976) have concluded from a study of the distri- contain uranium associated with sulphide minerals, pre- bution of sedimentary carbon, sulphur, uranium, and iron dominantly pyrite, whereas in the upper Huronian, radio- that It is not necessary to invoke an oxygen-deficient at- activity in conglomerate is largely due to thorium associ- mosphere. ated with iron oxides. During the Middle and Late The Huronian Supergroup is a thick sequence of Huronisr;, conditions became favourable for the preser- clastic sedimentary rocks with minor chemical sedimen- vation of iror> oxides. tary rock and tholeiitic basalt, as shown in Table 3. De- Glacial deposits are characteristic c! the lower and tailed references are provided by Card et at, (1972), J.A. middle Huronian. whereas the uppermost Huronian was Robertson (1969,1976), and Roscoe (1969). The clastic apparently deposited in a hot diy environment. The ratio sediments were derived from the adjacent Archean era- of ferric to ferrous iron in argillaceous rocks increases up ton and were deposited by southwesterly-flowing cur- the slratigraphic sequence, reflecting a change in gen- rents as diachronous beds. Grain size varied cyclically eral oxidation conditions. An upward increase in the on a basin wide scale. The depositional basin extended SiOj/AljOa ratio in argillaceous rocks reflects the in- east-west, and deepened towards the southeast. Hinge creased efficacy of chemical weathering during the Late zones, which later became major faults , controlled the Huronian. Variation in the Na2O/K2O ratio through the Hu- distribution of mafic volcanic rocks and produced ronian reflects changes in provenance from granitic rock marked variation in bed thickness and sedimentary fa- to "greenstone". The arenaceous rocks show similar cies. D.G. Innes and G. Bennett (Bennett 1978) have con- changes in provenance and efficacy of chemical weath- tinued field work and laboratory studies on the Huronian ering. The role of oxidation is apparent in the frequency of volcanic rocks to establish their distribution, correlation, red beds from within the Gowganda Formation upwards, and possible role in the formation of the uranium deposits as contrasted with the total lack of red beds in the lower and base-metal deposits. Minor changes in composition Huronian formations. Roscoe (1973, p.43) considered of similar rock types were caused by variation in prove- this to represent a worldwide change to an oxidizing at- nance and in efficacy of weathering-winnowing process- mosphere, an "oxyatmoversion". es. The workable uranium deposits of the Blind River-El- Radioactivity and heavy minerals are characteristic liot Lake camp are found as pyritic quartz-pebble con- of quartz-pebble conglomerate in the nearshore fluviatile glomerate beds in southeast-striking zones controlled by facies. In the lower Huronian, conglomeratic beds

10 TABLE 31 SUMMARY OF HURONIAN STRATIGRAPHY IN THE BLIND RIVER-ELLIOT LAKE AREA.

Depositions! Group Formation Lithotogy Thickness tin feet)' Environment Source Mineralization Cobalt Bar River QuarBite At least 1.000-Flaek Shallow water Source north Uke; at least 4,000- but currents Willisville variable Gordon Siltstone, I.ODO-Flack Lake; Shallow water Lake senditone 3.000-Willisville Lorrain Quartzite, 2.0006,000 Shallow water North- Th-U in north Cu? conglomerate, northwest

Gowganda Conglomerate 500-4.200 Glacial in north; North- greywacke, quartz- glacial-marine ite, siltstone in south Quirke Uke Serpent Quartzite 0-1,100 Shallow water Northwest Eipanola Limestone, 0-1,500 Shallow water Norhtwest U trace in Victoria Tp. dolottone, Cu in limestone against siltstone dicbeif Brace Conglomerate 0-200 Glacial-shallow North? water Hough !-ake Mlnlnagl Quartzite 0-3,000+ Shallow water West-northwest U near basement highs in west; north in southeast Pecorj Argillite 40-1,000+ Shallow water North- Traces U near basement northwest highs Ramsay Conglomerate 5-200 Glacial-shallow Northwest? Traces U where uncon- Laka water formable on Matinenda Formation Elliot Lake WsKim Argiiiin- 0-2.500+ Shallow water Northwest Traces U near basement (ftirbidite) highs Matinenda greywacke duartzite 0-700+ Shallow water Northwest U-ThRare Earths in arkose. conglomerate in base- conglomerate ment lows* Volcanic Andasite-basalt Local piles Subaarial Flack Uke F. U-Th in conglomerate rocks (faille volcanic rocks) Murray F. interbeds 'All U-deposits of commercial importance in the Blind River-Elliot Lake area are in the Matinenda Formation Abbreviations: Cu - Copper, Th Thorium, U - Uranium Footnote: 1To convert to metres, multiply by 0.3048 A METKS -_»ASf OF »AMSAY LAKE CONClOMtHATE . FHT SCM.EHHt.73O » i

*KHOME7IES SCHCMATIC CROSS-SECTION A-»-C

ZONES OF LEGEND MINERALIZATION • LIST OF WORKINGS ^ Matinanda Formation Greenstone I. Mocn Lake 1 Quirke 1 Mine 7 Can-Met Mine H. Quirke 2 Quirke 2 Mine I Stanleigh Mine J| Conglomerate Iron formation, outcrop «. Nordic 3 Denison Mine 9 Milliken Mine n Huronian-Archean Uranium mkieraKzation Ilia. Pardee . Spanish 10 Lacnor Mine —' contact at surface IV. Pecors American Mine II Buckles Mine Fault 3 Granite V. Whiskey 5 Panel Mine 12 Nordic Mine VI. Comer Lake 6 Stanrock Mine 13 Pardee Adit

Figure 6—Uranium deposits in Quirke syncline-B/iot Lake area. • DIABASE • ESPANOLA -±r

Figure 7a—Cross Section - New Quirke Mine after Rio Algom Mines Limited and J.A. Robertson (1976).

basement topography (Figure 6). In the eastern part of ous conglomerate bed) was found under the "Denison A the Quirke Syncline, there is a clear relationship between Reef" in the southeastern part of the mine. The uraniferous conglomerate beds and granite-"green- en-echelon pattern, with the oldest reef to the southeast, stone" contact areas and valleys over softer "green- conforms to the regional pattern of progressive basin ex- stone". At Moon Lake and at Pronto Mine, however, there pansion toward the northwest. Stratigraphic relationships is no clear relationship with basement geology which within the ore zone are illustrated schematically in Table raises the possibility that there may be other economic 4. uranium deposits underlain by granite. It is clear, how- At the Nordic Mine, the main ore bed consists of ei- ever, that the Pronto deposit is located on the flank of a ther conglomerate or conglomerate with quartzite over a regional basement high. All of these ore deposits occur in width of 3 m. The average grade has been 2.5 lbs U3Oe the Matinenda Formation. per short ton (0.13 percent). Another reef, the Lacnor The Quirke mineralized zone occurs on the northern Reef, locally occurs lower in the sequence and was limb of the Quirke Syncline (Figure 6) and is the largest mined where the grade attained 2.0 lbs U308 per short uranium resource in the area; it is 13 000 m long and from ton. In the eastern part of the mine, a third reef, the Par- 1800 to 5500 m wide. The Nordic mineralized zone on the dee Reef, attains ore grade, 2.3 lbs U3OB per short ton southern limb is 19 500 m long and from 1400 to 8000 m over 1.5 m. This reef extends eastward over a basement wide. The Pronto deposit (J.A. Robertson 1970) and the ridge into the Pardee and Pecors mineralized zones (Fig- unworked mineralized zones are of are of smaller dimen- ure 6). These reefs extend to the Stanleigh Mine. Opera- sions. tions were largely carried out in the Lacnor and Nordic At the Quirke No. 1 Mine, the main ore bed, the "Quirke A Reefs. As on the northern limb of the Quirke Syncline, Reef", is approximately 30 m above the basement and is other reefs (uraniferous conglomerate beds) of sub-mar- approximately 3.5 m thick (Figures 7a and 7b). Toward ginal grade or limited extent are known. the east, this bed is truncated by an unconformity at the Five types of boundaries to ore are known, as fol- base of the overlying Ramsay Lake conglomerate. lows: The Quirke No. 2 Mine and the Denison Mine lie to 1. Outcrop of the conglomeratic bed. the south where the Matinenda Formation is thicker. The 2. Contact with the basement surface, either a re- besl ore development here is in the "Quirke C Reef", also gional or a local "high". called the "Denison Reef", some 30 m below the Quirke A 3. Lateral thinning of the conglomeratic bed and Reef. The Denison reef normally comprises two conglom- thickening of intervening arkosic beds accompanied by a erate zones each 1.8 to 3.6 m thick separated by barren drop in grade of the radioactive unit. arkose 0.6 to 2.4 m thick. Other conglomerate beds, 3.6 4. In the Quirke Zone, an unconformity exists at the to 6 m thick, are known on both the Quirke and Denison base of the overlying Ramsay Lake conglomerate. Where properties. At the Stanrock Mine, another reef (uranifer-

13 Uranium Deposits of Ontario

H- + + + 900 LEVEL + «•- + + +

Figure 7b—Cross section - Agnew Lafce Mines Limited after D.S. Robertson (1964).

material from uraniferous conglomerate has been incor- These minerals occur with brannerite and uraninite in the porated into the Ramsay Lake conglomerate, the latter matrix. The ore minerals are brannerite, uraninite, and contains minor uranium mineralization. monazite. 5. Some areas have not been mined, either because Pyrite is the most common sulphide. It is concen- of unfavourable mining conditions due to faults, extensive trated in the matrix, and only rarely is there an indication fractures, or diabase dikes, or because of unfavourable in hand sample of replacement or fracture-filling in the milling conditions caused by alteration of the ore to albite, quartz pebbles. Individual grains may be rounded chlorite, and/or carbonate minerals. ("buckshot" pyrite) or subhedral to massive. R.G. Arnold Some of the foregoing relationships are illustrated in (1954) suggested that the pyrite was formed by sulphidi- Figures 6 and 7a. zation of detrital magnetite. He described pyrite grains with cores rich in leucoxene and considered these to have developed from ilmenite which had exsolved from Ore Mineralogy the original magnetite. The required sulphur may have Typical ore-bearing conglomerate of the Matinenda For- been derived from Lower Huronian volcanic rocks (J.A. mation consists of well-rounded, well-sorted, quartz peb- Robertson 1971; Bottrill 1971). P.J. Pienaar (1963) could bles in a matrix of quartz, feldspar, and sericite; the pyrite not distinguish between the trace-element suite of pyrite content averages 10 percent to 15 percent of the rock. in ore and that of pyrite in other rocks of the district. Al- Monazite and zircon are characteristic heavy minerals. though a wide variety of other sulphides and heavy min-

14 TABLE 41 CORRELATION OF QUARTZ-PEBBLE CONGLOMERATE REEFS, QUIRKE ZONE.

(Underlined beds have supported production) QUIRKE 1 &2 DENISON STANROCK (Rio Algom Mines) Denison Mines Ltd. Denison Mines Ltd. Ramsay Lake Formation Ramsay Lake Formation Quartz ite Quartzite Upper F Quartzite E Quanzite D Quartzite Floater reef (s) Quartzite Quartzite

CIQuirke 2) -— Quartzite Quartzite

Quartzite I.Q. (Interbedded quartzite) -flfll Quartzite B Quartzite Quart2ite FWC (Scraps) - - Scraps Quartzite Quartzita Quartzite Basement Basement Basement

erals has been identified, it should be stressed that these Elliot Lake "brannerite" has recently been studied by occur in very small quantities. J.A. Robertson (1976) pro- Ferris and Rudd (1971) and by N.J. Theis (1978). These vided a list of these and of the appropriate references. authors have concluded that the brannerite formed at a very low temperature during diagenesis as a result of ura- The major ore mineral at the Pronto Mine and in the nium migration to decomposing ilmenite. C.S. Ferris and "A Reef" of the Quirke Mine is "brannerite" (Thais CO. Rudd (1971) reached a similar conclusion for the 1973,1976). This was first described from the area by Nuf- brannerite (uraniferous leucpxene) of the Witwatersrand field (1954). Although some relatively fresh material has reefs. Uraninite is the second most important uranium been observed, brannerite is typically found as ovoid mineral at the Pronto Mine, and apparently is the most im- red-brown to black grains in a metamict state character- portant in the Nordic Zone and in the C Reef of the Quirke ized by bladed rutile surrounded by uranium oxide and Mine (Theis 1973,1976,1978, and 1979). Generally it oc- rare-earth oxides. This is the two-phase uranium-titanium curs as black subhedral grains approximately 0.1 mm compound of Pienaar (1963). Pienaar (1963), D.S. Rob- across. Ramdohr (1958) and D.S. Robertson (1962,1974) ertson and N.C. Steepland (1960), and Roscoe (1969) have described rounded grains. D.R. Oerry (1960) and suggest that the round grain shape has been caused by R.I. Thorpe (1963) have both concluded that the amount transportation and that the material is detrital. However, of partial substitution by TriO2 within uraninite has a re- P. Ramdohr (1957) suggested that the brannerite formed gional average of 6 percent. Table 6 summarizes the during metamorphism by the "Pronto Reaction", namely early published data en Elliot Lake uraninite which has UO2 + 2-3TiO2 = UTiOMOM. Experimental efforts to re- been subsequently confirmed by D.E. Grandstaff (1974). produce this reaction indicate that it takes place at tem- This corresponds to the composition of pegmatitic rather peratures in excess of those to which the rock had been than hydrothermal uraninite. subjected (Gainer 1959, Patchett 1959). The mineral Roscoe (1959a,b) has described monazite from the generally contains small inclusions of pyrrhotite and of ra- Elliot Lake ore and has pointed out that monazite contains diogenic galsna (Thorpe 1963). Table 5 lists published considerable uranium, and is, therefore, one of the ore partial analyses of "brannerite" from the Blind River-Elliot minerals. Monazite grains are normally rounded to su- Lake area. bangular and less than 0.3 mm in diameter. Grey varie- 15 Uranium Deposits of Ontario

TABLE S URANIUM, THORIUM, AND TITANIUM CONTENTS OF BLIND RIVER AFTER BRANNERITE AFTER J.A. ROBERTSON (1968a, p.92).

MINE AUTHOR COLOUR COMMENTS U3O8 ThO, T.O2 U3O8/ThO2 percent

Others than Blind River Thorpe (1963) 40-52 3.9-9.15 32-40 40-52 Nordic Patchett 11960) reddish brown altered 32.6 2.6 30.3 "2.5 Nordic Patchnt (1960) darker more glassy, le altered 32.2 305 17.9 Oeniion Roscoe (1959a) black 41 6.1 20 6.7 Denison Roscoe (1959a) dark brown 36 1.8 30 20.0 Quirke Roscoe (1959a) dark brown 24 1.7 37 14 Quirke Roscoe (1959a) brown 20 22 30 9.1 Quirke Roscoe (1959a) cream 6 \2 27 5.0 Con-Met Pienaar (1963) veinlet material 8.70 1.14 n.d. 7.6 Regional Thorpe (1963) 30 23 30 13

ties are strongly radioactive, and may contain uranothor- Thearkose interbedded with the ore conglomerate is ite or thorite as well as pyrite inclusions. Table 7 summa- generally greenish in colour and is crossbedded (Roscoe rizes the published data on monazite composition. 1969; J.A. Robertson 1968b). Normally, this crossbed- Thucholite, radioactive hydrocarbon, occurs in lami- ding is of the festoon type which is indicative of a fluviatile nae within the ore, and also as a secondary mineral, in environment. Arkose and pebbly arkose both show len- cross cutting fractures. Although its presence has long soid bedding and scour-and-lill structures. The conglom- been noted, little attention has been paid to it. The work of erate apparently was deposited in anastomosing or D.A. Pretorius (1975), D.K. Hallbauer (1975), and others braided stream channels. Lateral migration resulted in in the Witwatersrand of South Africa led V. Ruzicka and the coalescing of these channels to form sheets, the so H.R. Steacy (1976) to reexamine the Elliot Lake hydrocar- called reefs. bon; they suggested a biogenic origin for at least the la- Agnew Lake Area minated variety of thucolite. S. Kaiman and J. Horwood (1976) described a globular variety found on open sur- Stratiform uranium deposits in basal Huronian rocks faces within the Milliken Mine, and suggested that such also occur at Agnew Lake (see Figure 2, Figure 8; Little, thucholite formed as a result of the radioactive polymeri- Smith and Barnes 1972). These have recently (1976) zation of diesel fumes from underground mining equip- been brought into production using an in situ leaching ment. Uranothorite has also been identified (Roscoe and process. Due to unsatisfactory recovery rates, mining op- Steacy 1958), and Patchett (1959) identified coflinite in erations ceased early in 1980, the operation will continue altered material from the Nordic Mine. to recover uranium from broken material as long as this is Roscoe (1959a) has shown that the ratio of uranium economically feasible. The ore comprises gritty oligomic- to thorium in the ore is comparable to that of the base- tic conglomerate interbedded with arkose in a metamorp- ment. Lateral variations in the distribution of ore minerals hosed quartzite-argillite-conglomerate sequence which and of uranium-thorium ratios are discussed by Roscoe is probably equivalent to the Matinenda Formation of the (1959a), and R.I. Thorpe (1963). These variations are Elliot Lake area. Pebbles at Agnew Lake are smaller and best explained by the relative stability of monazite during sparser, and pyrite is less conspicuous. The ratio of tho- sedimentary transport. Similar results have been ob- rium to uranium is generally higher than Elliot Lake, tained by Theis (1978,1979). reflecting the presence of substantial uranothorite and Locally, individual conglomerate units may contain monazite. Post-Huronian deformation has been consider- as much as 20 lbs or more of U3O8 per short ton (1 per- ably greater, resulting in steeper dips, more pronounced cent U3Oe), but over mining widths of the order of 2.7 to 9 cleavage, and stretching of pebbles. H.W. Little, E.E.N. m, the average grade of beds mined to date is 2 to 3 lbs Smith, and F.Q. Barnes (1972) have estimated the re- of UaO8 per short ton. Currently, millheads are 2 to 2.5 lbs serves to be 8000 short tons U3O8 in material grading per short ton; as mining continues, the grade will continue 1.88 lbs of U3O8 per short ton. The cleavage, near vertical to drop. Lateral extensions of the Quirke and Nordic ore dips, and metamict minerals have enhanced the leaching zones contain considerable amounts of material with av- process. Cross-faulting has hindered the development of erage grades of 0.5 Ib to 1.5 lbs U3OS per short ton, as do large stopes that had been planned originally. The struc- the Pardee and Moon Lake zones (Figure 6). ture of the Agnew Lake deposit is illustrated in Figure 7b.

16 TABLE 6 URANIUM AND THORIUM CONTENTS IN BLIND RIVER URANINITE, AFTER J.A. Robertson (1968a, p. 93).

MINE AUTHOR U3O8/Th02 percent Denison Pienaar (19631 43.4 5.6 8.65 Denison Pienaar(1S63) 39.0 7.2 5.4 Denison Pienaar (19631 55.5 5.4 10.3 Nordic Patchett(1960) 55.25 6.25 8.85 Quirke Wanless and Traill 11956) 51.7 4.1 12.6 Pronto Wanless and Traill (1956) 57.0 5.12 11.1 Nordic Roscoe (1959a) 64 6.3 10.15 Denison Roscoe (1959a) 60 5.9 , 10.2 n 1 Panel Thorpe (1963) 29.6 3.84 7.7 Regional Thorpe (19631 60 6 10

^ Contaminated?

Cobalt Embayment tually quartzite of unknown provenance, or lean cherty That part of the Southern Province which lies north of ironstone similar to that which forms the iron formations in Sudbury previously has been termed the Cobalt Plate nearby Archean "greenstone" belts. Showings in Vogt (Card ef al. 1972). However, neither thrust faulting nor Township and Turner Township (J.A. Robertson 1968a) plate tectonics have been recognized as significant fac- reportedly contain trace amounts of gold. tors in the regional geology and the term, Cobalt Embay- Deposits in the Cobalt Embayment are clearly de- ment, is currently preferred. Lower Huronian rocks are in- rived from Archean terrain, but are of different prove- termittently exposed in the southern part of the Cobalt nance than those at Agnew Lake and Elliot Lake. They Embayment (Card and Lumbers 1977), but are largely may be slightly younger, but must be considered part of concealed there by the Nipissing Diabase and upper Hu- the same metallogenic province. Further prospecting and ronian rocks. The regional geology has been discussed exploration in the southern part of the Cobalt Embayment by J.E. Thomson (1960) and by H.D. Meyn (1972). Pre- should hopefully yield more data of stratigraphic, and cise stratigraphic correlation with the lower Huronian of econ •>mic value. the Elliot Lake area is unclear, but rocks equivalent to the Mississagi Formation are present. At the base of all expo- sures of these, there are anomalous concentrations of Gencsii of the Elliot Lake Pyritic Quirtz-Pebble Uranium uranium in argillaceous, quartzite and of uranium and Deposits (locally) gold in conglomerate (Figure 8). Uranium and thorium mineralization occurs at a number Early descriptions of uraniferous conglomerate in the of localities throughout the world in quartz-pebble con- Cobalt Embayment (Thomson 1960; Meyn 1972; J.A. glomerate which is rich in pyrite, and especially in the Robertson 1968a) compared these rocks with the Blind gold-rich Witwatersrand of South Africa. The origin of River-Elliot Lake oligomictic conglomerate. However, this these conglomerate beds has been much debated. The comparison is invalid. Much of the conglomerate is po- similarity of deposits in the Blind River-Elliot Lake-Agnew lymictic and contains fragments of granite, "greenstone", Lake area to the well known deposits in the Witwaters- and cherty ironstone, distributed in an argillaceous quart- rand (South Africa) and Jaccbina (Brazil) areas has been zose matrix. Many of the so-called quartz pebbles are ac- noted by C.F. Davidson (1957,1965), Derry (1960), Jou

TABLE 7 ANALYSES OF BLIND RIVER MONAZITES, AFTER J.A. ROBERTSON (1968a,p.93).

ROSCOE (1959b) THORPE (1963)

1 2 3 4 Range Average Cotour orange yellow grey grey

ThO2 5.9 3.9 6.7 5.9 5.6-6.2 5.6 U3°8 0.31 0.95 1.65 2.9 1-2 1.4 U,OB/ThO, 0.0525 0.244 0.246 0.492 0.18-0.32 0.25

17 Uranium Deposits of Ontario

SUPER/OR PROVINCf.

GRENVILLE PRO VINCE

Sturgaon Falls

Fault Sudbury Irruptive Huronian Supergroup Uranium Deposit Upper Units

Elliot (E) and Alkalic Complexes Hough (H) groups Unconformity Lower Precambrian Presumed Lower Huronian Limit

Figure 8—Uranium deposits - Cobalt Embayment and Agnew Lake Areas. 18 bin (1960), W.H. Gross (1968) and Ramdohr (1958). The Matinenda polymictic conglomerate and polymictic relationship of all these to major unconformities, particu- conglomerate in the Ramsay Lake, Bruce, and Gow- larly those marking the Proterozoic-Archean boundary, ganda Formations of the Huronian Supergroup do rA has also been emphasized (Derry 1961; Davidson 1965; carry markedly high uranium values, although all con- J.A. Robertson 1967, 1968a, 1S68b, 1969, 1970, 1975, glomeratic beds, particularly the Bruce Formation, carry 1976,1977,1978a, 1978b; and Thomson 1960). In the El- some pyrite and pyrrhotite. An exception to this lacf. of liot Lake camp, this unconformity can be dated at about uranium occurs where a polymictic conglomerate ted 2500 my, and it is clear that mineralization did not persist unconformably overlies uraniferous oligomictic conglom- beyond 2155 my. In Ontario the period from 2500 to 2400 erate (J.A. Robertson 1968b, 1969). my seems to have been the most favourable. The sericitic matrix of ore-bearing conglomerate is Davidson (1957) and Heinrich (1958) considered all similar to the underlying sericitic regolith and was proba- conglomeratic mineralization to be of hydrothermal ori- bly ived from it. Uraniferous oligomictic conglomerate gin. They cited the supposedly high ratio of uranium to w' ,n a green arkose sequence is characteristic of the thorium, the high ratio of titanium to iron, the association b 'ss\ Huronian Supergroup throughout the Elliot Lake with Ti.Co, Ni, Th, and U, and the mineralogy, name!y, area. However, significant thicknesses and grades of ur- gold, brannerite, uraninite, and pyrite as evidence of a aniferous rock occur only where the basal beds are part hydrothermal origin. Joubin (1954) suggested the "Kew- of the Matinenda Formation. eenawan" diabase as a source, but in a later paper, Jou- Quartz veins and other evidence of intense hydroth- bin (1960) admitted that mining evidence clearly indi- ermal activity are not conspicuous within rocks of the cated that diabase post-dated the uranium area, and bear no sympathetic relationship to the ura- mineralization. Davidson (1957) suggested that the (sup- nium deposits. Where found, the associated mineraliza- posedly) post-Huronian granite lying to the southeast of tion is of copper and other sulphide minerals. Within the the Blind River-Elliot Lake area had been the probable Blind River-Elliot Lake-Agnew Lake camp no indication source. However, much of the granite formerly consid- shows that either Nipissing Diabase or the olivine dia- ered to be of possible post-Huronian age has since been base intrusions were a possible source of substantial ra- proven to be older than the Huronian. Only the Cutler dioactive mineralization. There is, however, evidence that Granite, exposed south of the Murray Fault, 22 km south the ore was subjected to local intense alteration, and that of Elliot Lake, is currently considered to be of post-Huro- all rocks became mineralized with sulphides during intru- nian age (J.A. Robertson 1967, 1971, 1973; Card et al. sion of the Nipissing Diabase and regional folding. Age 1972; Van Schmus 1965). determination data are consistent with this concept (Van Davidson (1965) later returned to the question of the Schmus 1965; Roscoe 1969). Minor uranium, copper, origin of conglomeratic ore bodies, and considerably nickel±bismuth, and silver mineralization have been ob- modified his earlier views. The revised hypothesis may be served in diabase contact zones at two localities, for ex- summarized as follows: ample at Sowerby near Thessalon and east of Cobre a) Deposition of molassic sediment in a deeply sub- Lake (J.A. Robertson 1968a, 1971, 1973). The uranifer- siding basin, with digorr.ictic conglomerate near the ous mineral here is pitchblende. base; The overall distribution of beds and th? variations of b) Instrastratal leaching of metals by groundwater; ore thickness and grade are more consistently explained c) Prolonged intrastratal migration, allowing mineral- by the modified placer hypothesis, which the author has ized groundwater to sink to the oligomictic conglomerate supported (J.A. Robertson 1967, 1968a,- 1968b, 1969, beds, where the metals would be precipitated; 1970,1971, 1973,1975,1976,1977,1978a, 1978b) than d) The thermal energy for cycling groundwater would by the simple placer hypothesis. Recent mineragraphic be derived from post-sedimentation intrusions, the final studies by Ferris and Rudd (1971) and by Theis cycle of ground water taking place during the Hudsonian (1973,1976, 1978, 1979) have added evidence to sup- (Penokean) orogeny, as evidenced by the 1700 my age port the modified placer hypothesis. This hypothesis pro- for uraninite and brannerite obtained by J.A. Mair ef al. poses that the deposits were derived from Archean ter- (1960). rain to the north and northwest, transported by rapidly However, Roscoe (1969) showed that the isotopic moving water, and deposited in a near shore flviatile envi- compositions found by Mair er al. (1960) are better ex- ronment under cold, possibly frigid, reducing conditions plained by invoking the resetting of dates on Archean-de- about 2500 my ago. Mafic volcanic rocks were simultane- rived detrital minerals. ously accumulating in the basin. The uranium deposits McDowell (1957), Pienaar (1963), Roscoe (1957, were later subjected to diagenesis and to minor alteration 1959a, 1959b, 1969, 1973), and D.S. Robertson (1962) during subsequent intrusive, metamorphic, and tectonic adopted a placer origin. Holmes (1957) suggested that events, but were not subjected to either erosion or leach- the ores were of syngenetic (placer) origin that were ing. modified by later events. Derry (1960) has also sug- The foregoing genetic hypothesis has led the author gested a syngenetic origin for the uranium mineralization, to a systems-analysis approach to resource-potential and but has raised the possibility that the uranium was carried exploration-potential assessment. The geological factors in solution and was precipitated within gravel by means (parameters) inherent in source, transportation, deposi- of bacterial action. Joubin (1960) had similar concepts, tion, modification, and preservation have been identified but did not include bacterial precipitation. and their efficacy assessed. This systems ap-

19 Uranium Deposits of Ontario

proach has been expanded by the Federal-Provincial Re- Wynne-Edwards, under the auspices of the Geological source Appraisal Group (Ruzicka 1977a,c). As a further Survey of Canada, carried out detailed work in the West- aid to stratigraphic and economic studies in the Elliot port-Gananoque region. The results of these studies were Lake camp, all drill logs in the files of the Ontario Govern- summarized by S.B. Lumbers (1964,1967) and H.R. ment have been abstracted in standard format and no- Wynne-Edwards (1972). Lumbers related the mineral de- menclature, and a computer file has been created. This posits, including uraniferous pegmatite, to areas of high- file will be made public as soon as the procedures for grade regional metamorphism. FollcAving earlier workers. protecting confidential information have been evolved. A Lumbers considered the quartz monzonite batholiths of manual file of public data and location maps is presently the Bancroft area (Figure 9) to have been intruded during available (personal communication, Leahy 1973, Mineral a major period of metamorphism and deformation, peak- Deposits Section, Ontario Geological Survey, Toronto). ing at 1125+25 m.y. The presence of later granitic intrusions was also noted. Little et al. (1972) and J.A. Robert- Grenville Province son (1975) similarly related uranium deposits of the Bancroft area to magmatic and metasomatic processes, The Bancroft area occurs within the Grenville Province of but they noted that uranium elsewhere in the Grenville the Canadian Shield (Figure 1). This area is of interest be- Province had been concentrated by metamorphic pro- cause of its wide variety of urar-iferous minerals and be- cesses. The presumed uranium-concentrating magmatic cause of its geological settings for uranium deposits. processes have been considered to be related to the The classical work on the Bancroft area by F.D. Ad- syn-Grenville-orogeny granitic bodies, which have also ams and A.F. Barlow (1910) led to the recognition of its been described as mantled gneiss domes. Younger mineralogicai importance. Uraninite was found at the granitic rocks apparently are barren. Richardson Mine (later Fission Mine) [7]' near Wilber- During the 1970s, the Grenville Province was re-ex- force .n 1922 (Ellesworth 1922) and provided incentive plored for uranium, and new discoveries have been for Ellesworth in his classical studies of radioactive miner- made in the Bancroft area, both in red pegmatite and als in »>• Georgian Bay - Ottawa Valley region. The Fis- calc-silicate rocks. White pegmatite in the MacTier-Parry sion Mine was developed as a possible source of radium, Sound area (16), and in the Kaladar-Sharbot Lake area but the venture failed. During and after World War II, this, (18) east of Bancroft have also been explored. Irregular part of the Gre nville Province wa,s again examined, lead- distribution of the pegmatite and of the uranium minerali- ing to the disci wery of the Centre Lake deposit near Ban- zation have precluded the delineation to date of potential croft in 1952. This became the area's first producing orebodies. In the immediate Bancroft area (III)2, several mine, the Bicroft Mines [4] in 1956 and Faraday [2] Mine pegmatite depots with economic grade (1 to 2 lbs followed in 1957. The Dyno [5] and Greyhawk [6] proper- U3O8), but relatively small tonnage (0.5-2 million tons) ties also had minor production. have been outlined. If a sufficient number of these be- Numerous discoveries in the Grenville Province have come identified within a suitable transportation distance, been described by J. Satterly (1957) and by D.F. Hewitt a central custom mill would be a viable operation. Calc- (1957). The classification of deposits developed by them silicate (skarn) deposits could be handled by a separate (Table 7) has formed the basis of subsequent reviews by custom mill if preconcentration of the uraninite and/or ef- S.C. Robinson and D.F. Hewitt (1958), A.H. Lang et al. fective recovery of uranium from a carbonate-rich host (1962), and H.W. Little et al. (1972). Hewitt (1967) listed were to be perfected. Preconcentration, possibly by ra- the then known occurrences in Southern Ontario and diometric sorting, would enhance the viability of the summarized their nature, distribution, and production smaller pegmatite occurrences. and/or assay data. From 1956 to 1964, the Bancroft camp Since 1974, the Ontario Geological Survey has spon- produced a total of $105 million, about 5,500 tons U3OB sored mapping and mineral-deposit studies in the Gren- (4240 metric tons of ...ranium). Ore grade was approxi- ville Province. Reinterpretation of the structure and stra- mately 0.17 percent U3O8, with from 0.0225 to 0.2 per- tigraphy of the area, particularly by Lumbers (1975) and cent ThO2. The uranium occurs within pegmatite and its E.G. Bright (1974,1977), has led to the postulate that sra- distribution is controlled by the distribution of mafic min- tabound uraniferous and potassic pegmatite could have erals, particularly magnetite, and by late fractures. Close been derived by anatexis of arkose basal to the Upper sampling, on a grid pattern of 7.6 m or less, has been re- Precambrian Grenville Supergroup. The pegmatite has quired to provide reasonable grade control, and it has intruded the overlying carbonate-volcanic units of the been considered necessary to dilute high grade ore for middle Grenville Supergroup. Uranium presumably has better uranium extraction. been concentrated and precipitated by interaction with During the late 1950s and early 1960s, the Ontario mafic minerals derived from the wall rocks, such as horn- Department of Mines carried out an extensive detailed blende, pyroxene, biotite, and magnetite, which occur as mapping programme in the general Bancroft area. Much remnant inclusions around and within the pegmatite. exploration work and university research provided further Bright has suggested that the wallrock may also have data. The early work already referred to, was carried out contributed uranium and/or thorium to the resulting de- by Satterly and Hewitt, and the later work by Lumbers. posit.

11ndicates location on Figure 9. 2 Indicates location on Figure 2.

20 CLASSIFICATION OF URANIUM DEPOSITS RESERVE (TONS) GRADE

S ID KUomnrat

LEGEND ORDOVICIAN | 2° | Middle Ordovician

URANIUM DEPOSITS PRECAMBRIAN | '6 | Carbonatite-Aikalic Complexes 1 MacDonald 2 Faraday | « | Late Mafic Igneous Rocks Canadian All Metals 3 [ K | Late Felsic Igneous Rocks Bicroft 4 MIDDLE TO LATE PRECAMBRIAN Dyno 5 13 6 Greyhawk | | Early Mafic and Ultramafic Igneous Rocks 7 Fission ^B Carbonate Metasediments Silver Crater 8 | " | Clastic Metasediments 9 Cardiff 0 Loon Lake {HI Mafic to Felsic Metavolcanics

Figure 9—Uranium deposits - Bancroft area. 21 Uranium Deposits of Ontario

TABLE 8 | URANIUM DEPOSITS OF THE BANCROFT DISTRICT (After Satterly 1957).

I. Deposits in granitic and syenitic pegmatite A. Zoned pegmatite (MacDonald) 1 * B. Unzoned pegmatite 1. Red pegmatite (Faraday) 2 2. White pegmatite (Loon Call Lake) 10 II. Metasomatic deposits in calcareous rocks A. Mete somatic deposits in marble (Canadian Alt Metals) B. Metasomatic deposits in metamorphic pyroxenite (Bircort, in part) III. Hydro thermal deposits A. Calcite-ftuorite-apatite veins (Fission) 7 B. Catcite-fluorite-apatite-biotite-pyroxene veins (Cardiff) 9 C. Anhydrtte-calcite-uralite veins (Faraday, mf/art) 2 IV. Carbonatite-associated deposits A. Calcite-biotite-hornbfende-apatfte vein (Silver Crater) 8 * indicated location on Figure 9.

Other researchers, for example Fowler (1978) and tions are given by Satterly (1955); Hewitt 1957; and J.W. J.B. Gordon (Geologist, Mineral Deposits Section, per- Griffith (1967), and Lang era/. (1962). sonal communication, 1978), suggest that much of the Red Zoned Pegmatite uranium is late-stage and derived from truly intrusive granite. The distribution and stratigraphic relationships of The MacDonald Feldspar Mine [1] north of Bancroft is a uranium deposits are being further studied by J.B. Gor- typical red radioactive zoned pegmatite. The main peg- don and S. Masson (1977,1978). matite dike strikes west and dips 60 to 70°N. From the borders inward it contains a fine-grained granite zone, a Away from the main Bancroft camp, e.g. in the Mac- Tier and Sharbot Lake areas (Figure 2; Barlow and Ware medium-grained albite microcline-quartz pegmatite 1977; J.A. Robertson 1977), the pegmatite is principally zone, coarse-grained albite microcline-quartz pegmatite "white" and occurs in bodies with nebulous boundaries. zone, a coarse-grained quartz microcline perthite peg- This pegmatite is clearly the result of metamorphism and matite zone, and a central core of massive quartz and mi- partial melting of the sedimentary country rocks (Wolf nor microcfine. Coarse pink to white calcite pods occur 1977). The pegmatite carries uraninite, and fractures are within the dike. Accessory minerals are hornblende, py- commonly coated with uranophane. Allanite is a common roxene, biotite, chlorite, scapolite, garnet, allanite, accessory, and molybdenite may also be present. sphene, and magnetite in the outer zones, and cyrtolite, The mode of occurrence and history of uranium dep- ellsworthite', allanite, fluorite, uranothorite, galena, and osition in the Bancroft area is complex (Table 8). Accord- uraninite in the central part (Satterly 1957; Lumbers ing to Satterly (1957) and Hewitt (1957), there appear to 1967). Also noteworthy are the hematitic alteration and have been three stages in the sequence, and these fre- fractures radially arranged about the allanite crystals. quently overlap even in a single deposit. These stages There is also development of smoky quartz in or near are as follows: zones of higher radioactivity. Red Unzoned Pegmatite 1. Pegmatitic stage: dilatant injection accompanied by assimilation and replacement; deposition of uranium Bodies of red unzoned pegmatite near Bancroft are the related to wallrock interaction, only pegmatite deposits in Canada that have produced 2. Metasomatic replacement stage, an appreciable amount of uranium. They are more alka- 3. Hydrothermal vein stage, usually calcite-fluorite- apatite veins. The brief descriptions which follow are largely re- 1 Ellsworthile is a synonym for uranpyrochlore (see Steacy and peated from Little et al. (1972). More detailed descrip- Kaiman 1978, p.128).

22 line than the white pegmatite and are characterized by establishing reserves of over 1 000 000 tons grading uralitized pyroxene rather than biotite. Much of the ore- 0.144 percent U3OB. The property* was maintained until bearing pegmatite is syenitic. Within and adjacent to the late 1976 when it was brought into production by Mada- orebodies, deep purple-red hematitic alteration of felds- waska Mines Limited on the basis of a sales contract and par is characteristic. proven/probable reserves of 1 023 086 tons grading 2.9 The Bicroft Deposit [4] lies on the east side of the lbs U3Cyton. Inferred reserves are 1 600 000 tons grad- Cardiff mantled dome within a belt of amphibolite and ing 1.85 lbs U3O8/ton. In 1977, production was 440 753 paragneiss that strikes north and dips 55°E. For a dis- lbs U3O6 from 295 068 tons of ore. During the latter part of tance of 5.5 km, this zone is intruded by en-echeton pipe- 1977 and early 1978, both the grade and tonnage milled like bodies of pegmatite than range up to 3 m by 90 m in was improved (Madawaska Mines, 1977 Annual Report). size and 410 m in length. The long axes of the dikes plunge from 40° to 70° east. The pegmatite is granitic, Calc-Sllicate Deposits with substantial pyroxene and some biotite. The ore min- Thorite, uraninite, and uranothorite occur as dissemi- erals are uranothorite and uraninite, with accessory allan- nated deposits in marble, calc-silicate rock, and meta- ite, zircon, titanite, pyrite, pyrrhotite, and molybdenite. morphic pyroxenite, usually near the contact of a granitic, The Faraday (now Madawaska) [2] property is un- syenitic, or pegmatitic intrusive. Frequently, there is a de- derlain to the north by gneiss, succeeded southward velopment of calc-silicate minerals within marble, such as firstly by syenitic gneiss and minor marble, then by diopside, tremolite, scapolite, phologopite, apatite, mag- strongly lineated coarse-grained amphibolite and meta- netite, pyrite, and so on. Salmon pink to red colouration of gabbro, then by finer grained "migmatite" with pods of the marble is its characteristic feature. The uranium-bear- marble and quartzite, and finally by granitic rocks, mainly ing zones are irregular in size and shape, and the distri- coarse grained to pegmatitic with minor gneiss. All rock bution of the uranium mineralization is erratic. The term, types in the "migmatite" unit are intruded by irregular skarn, has been used to describe these deposits. How- bodies of pegmatite. Distribution of the pegmatite bodies ever, this implies metasqmatic development of the calc- indicates a plunging fold (Figure 10). This fold is a syn- silicate minerals, and they may alternatively be due to re- form with an axial plane which dips 45°S and an axis gional metamorphism of impure limestone. The uranium which plunges about 32°SW. An antiform to the north is probably has been introduced. less well defined; its axial plane dips vertically. In the deeper levels, the plunge of the synform appears to Hydrothersul Vein Depofite flatten (Chief Geologist, Madawaska Mine, Ralph Alexan- Hydrolhermal calcite-fluorite-apatite veins of the Wilber- der, personal communication, 1978). force area, namely the Fission Mine [7] (Lang et al. 1962; Recent work indicates that ore shoots at the Faraday Rowe 1952), carry uraninite and uranothorite. They occur (Madawaska) Mine are erratically scattered in pegmatite as lenticular, discontinuous, fissure filling veins from a that ranges in composition from granite to syenite. The few cm to 4 m wide, and up to 90 m long. The veins are ore-bearing pegmatite appears to be most common frequently well-banded, with alternating narrow stringers where the host rock is amphibolite, which may have been of white calcite, purple fluorite, and red to green apatite. chemically favourable for the precipitation of uranium Banding is parallel to vein walls. The veins are usually minerals. The most evident alteration in the vicinity of ore- steeply dipping, but their vertical extent is limited be- bodies is hematization. This suggests that at least some cause they pinch and swell intermittently. of the ore was deposited hydrothermally. The host rock of the Fission Deposit [7] is hybrid Pegmatite at the Faraday (Madawaska) consists of gneiss. The main deposit strikes N50°E, dips 30°E to peristerite, microcline, green diopside, pyroxene largely S40°E and is 60 m by 3.7 m. It exhibits zoning from the altered to uralite, locally antiperthite, and commonly walls inward, as follows: (1) oligoclase and microcline; (2) quartz. Accessory minerals are magnetite, zircon, oligoclase-microcline, antiperthite, and hornblende; and sphene, pyrite, marcasite, hematite, calcite, uranothorite, (3) a calcite-fluorite-apatite core. Other minerals present uraninite, thorite, allanite, and secondary uranophane are pyroxene, biotite, magnetite, and minor uraninite, al- and beta-uranophane. In the upper parts of the deposit, lanite, uranothorite, zircon, sphene, molybdenite, pyrite, the pegmatite contains selenite; in the lower levels, anhy- and pyrrhotite. The deposit exhibits characteristics of drite occurs both within and away from pegmatite (Little both pegmatite-related and vein type deposits (Rowe 1972). H.W. Little (1972) favoured the concept of a pri- 1952; Little et al. 1972). Other hydrothermal mineraliza- mary magma that contained calcium sulfate and which tion that is genetically related to uraniferous pegmatite was partly to almost completely fractionated. The abso- occurs as the aforementioned anhydrite-calcite-uralite lute ages of uraninite from the pegmatite and the anhy- veins on the lower levels of the Faraday (Madawaska) drite are in the order of 1020 to 1060 my, slightly older Mine. than the 960 to 975 my age assigned to the Grenville orogeny. The ratio of thorium to uranium is quite constant The Silver Crater property [8] lies in Faraday Town- throughout the deposit at about 1:2. ship about 13 km west of Bancroft. In 1953, betafite was found here in a former mica quarry, within a carbonate- The Faraday Mine was inactive from 1964 until rich mass of large crystals of hornblende, biotite, apatite, 1966,when the mine was re-opened and further develop- and zircon. The hornblende crystals are up to 1.2 m ment and exploration were undertaken (1966-1970), across, biotite flakes are 0.9 m across, and the apatite

23 Uranium Deposits of Ontario

FMt

M*tr*»

LEGEND

| Or*

I I AmpAmphibolit:) mtagtbbro, piragntit*

F/gure 10—Plan of 450 foot tevel - Faraday (Madawaska) Mine, after Little et al. (1972).

24 several cm up to 0.6 m. The property has been explored Greenwich Lake lies within the Quetico Subprovince by stripping, drilling, and by an adit. The carbonate min- of the Canadian Shield and the following easterly-striking eralization occurs over a length of 120 m and a width of rock units are exposed from south to north: metasedi- about 15 m, with a maximum width of 30 m. The uranium mentary rock, migmatite. quartz monzonite, and migma- grades have not been reported. Marginal areas contain tite. The border phases of both migmatite zones include mica, hornblende, feldspar, and apatite. The alteration lenses of uraniferous white pegmatite, although both the zone extends into the country rock and is characterized pegmatite and the uranium mineralization are less well- by calcite, biotite, hornblende, albite, and pyroxene, and developed in the southern migmatite zone. All rock units the following accessory minerals; apatite, sphene, are cut by diabase dikes, northwest-trending faults, and fluorite, and pyrrhotite. Minerals within the carbonate are sub-parallel radioactive sulphide veins (Figure 11). aligned parallel to the contact. All of the apatite is Uranium occurs in the following three modes: fluorapatite. Satterly (1957) concluded that the minerali- 1. Uraninite and uranophane occur within white peg- zation was related to the calcite-fluorite-apatite veins, but matite in the migmatite zones. The best mineralization is also noted the similarity to pyrochlore-bearing igneous accompanied by abundant biotite and blue-green apa- carbonate bodies. The proximity to faults of the Bonnech- tite. The overall grade of the pegmatite is less than 0.5 Ib ere graben (Figure 1), strengthens the theory that the Sil- U3Oe/ton (0.025 percent), although locally selected sam- ver Crater mineralization is of alkalic affinity because this ples give higher grades. graben is a sub-system of the St. Lawrence-Ottawa Val- 2. Pitchblende occurs in quartz veins with either py- ley graben. Elsewhere, this graben is accompanied by al- rite or marcasitie. These veins fill joints, principally within kalic intrusive rocks and associated fenite. the quartz monzonite. The Silver Crater property is a well-known mineral- 3. A pitchblende-marcasite-pyrite vein located along collecting site, particularly for betafite. Crystals 0.4 cm to a northwest-trending fault typically contains from 0.5 to 2 4.6 cm long are common; most are less than 2.5 cm. percent U3O8. Altered rock fragments in the fault breccia These crystals are usually surrounded by deep-red he- have been compared with rocks of the Sibley Formation matitic haloes up to 0.8 cm in width. (Franklin 1978), but the author and Carter (1977) consider these to be altered quartz monzonite formed from Lake Superior Basin country rock which has been strongly hematized adja- Uranium mineralization has long been known around the cent to the fault. Assays and vein widths are given by Rio- margins of Lake Superior. The best-known localities are canex (Regional Geologist's Files, Ontario Ministry of Nat- the Thunder Bay area (5), where Lower, Middle, and Up- ural Resources, Thunder Bay) and by Carter (1977). per Precambrian mineralization occurs, and the Montreal An association of lithology, structure, and mineraliza- River area (10), which is believed to be the site of the first tion similar to that at Greenwich Lake has been reported recorded uranium mineralization in Canada. Several ge- from the Good Morning Lake Fault at Innes Lake some 10 netic types and ages of mineralization are interrelated km east of Greenwich Lake (Fenwick and Scott 1977; within this metallogenetic province. Alkalic complexes Franklin 1978). Over the last few years, prospecting activ- also occur within this area. ity in the Thunder Bay area has been fairly intensive and several other radioactive occurrences have been identifi- Thunder Bay Area (5)1 ed. Airborne gamma-ray spectrometry and/or ground fol- Early reports by T.L. Tanton (1931,1948) and Ellesworth low-up work have indicated radioactivity in the Sibley For- (1934) indicated the presence of uranium mineralization mation of the Sibley Peninsula. Low radioactivity has also with silver, sulphides, and anthraxolite in the vicinity of been noted in black shale of the Rove Formation and in Thunder Bay. In 1949, T. Christiansen discovered radio- tuffaceous shale and sandstone of the Gunf/int Formation activity in a sulphide showing near Greenwich Lake 51 near Kakabeka Falls, where Fenwick and Scott (1977) re- km northeast of Thunder Bay. Trenching and diamond ported 0.004 percent U3Oe in mud-ball tuff. Ruzicka drilling during the 1950s confirmed the presence of pitch- (1976,1977a and b) discovered uraniferous mineraliza- blende and sulphides in a northwest-trending fault zone tion (up to 540 ppm U), confirmed by Fenwick and Scott which transects a migmatite complex (J.A. Robertson (1977), at the Enterprise Mine which occurs near the 1968a). Uranium was also identified in pegm; ••itic phases Lower Precambrian-Upper Precambrian unconformity. of the complex. The uraniferous mineral has been identified as coffinite. In the 1970s, the Christiansen showing was acquired Ruzicka used a car-borne spectrometer to discover by MW Resources Limited who optioned the property to radioactivity in an amethyst-coated fracture exposed in a Rio Tinto Canadian Exploration Limited, who in turn map- road cut on Highway 17 at Pearl Lake. J.A. Robertson ped the property (Assessment Files Research Office, On- (1977) and Ruzicka (1978) have confirmed radioactivity tario Geological Survey, Toronto; Figure 11). The property at several of the amethyst-bearing localities in the Thun- has been visited inter alia; by K.G. Fenwick and J.F. Scott der Bay-Dorion area. The radioactive minerals at these (1977), Ruzicka (1976), J.A. Robertson (1977), M.W. Car- localities are believed to be pitchblende and/or coffinite; ter (1977), and J.M. Franklin (1978). they have a high ratio of uranium to thorium, as determined with a portable gamma-ray spectrometer. The foregoing and other reported uranium occurrences are expressions of one metallogenic province. 1 Number in parenthese indicates location on Figure 2. The original concentration of uranium took place in the

25 Uranium Deposits of Ontario

twxh

Figure 11—Uranium deposits in the Greenwich Lake area, after Franklin (1978).

early crustal rocks of the area and secondary concentra- pitchblende was made in Canada (Le Conte 1847; Logan tion took place during the development of pegmatite. Pri- 1863). The general locality was rediscovered in 1948 by mary uranium mineralization is present in the quartz mon- R. Campbell (Lang 1949; Satterly and Hewitt 1948) who zonite. A Late Precambrian unconformity and faulting found pitchblende at Theano Point, and sparked a stak- both permitted circulation of water at relatively low tem- ing rush and further discoveries in the Montreal River perature, allowing further concentration of pitchblende area. along with amethyst and/or sulphides, mainly in open The discovery locality was explored on surface and fractures and fault zones. The best mineralization occurs underground by Camray Mines Limited. Ouartz-calpite- where such fractures cross rocks which are already min- pitchblende veins are found at the contact of a Late'Pre- eralized. Some of this mineralization has probably been a cambrian diabase dike and red coarse-grained granite. source of the uranium deposited either detritally or chem- The granite locally has pegmatitic segregations with mi- ically in younger Precambrian sedimentary rocks. Depos- nor amounts of uraninite. Yellow and orange alteration its of the Christiansen type may be the nearest equivalent products are locally present. The veins are typically less in Ontario of deposits within the Athabasca Basin of Sas- than 0.4 cm wide, but locally, areas are as wide as 5 cm. katchewan. They are locally parallel to the contact but elsewhere are oblique, even perpendicular, to the contact, (Figure 12) in Montreal River Area [10] zones up to 1.2 m wide and 1.2 m deep. They are characterized by an adjacent zone of hematization several cm The eastern margin of the Lake Superior basin is of histor- wide. Calcite, hematite, and chlorite are characteristic ical interest; it was here that in 1847 the first discovery of

26 Lake Superior

Cove

LEGEND

Diabase dyke

Granite, pegmatite, pegmatized granite

Pitchblende veinlett, observed

Fractures giving high readingt on Geiger oounter

1 \.

so HW ft SCALE h -f O » 20 30

Figure 12— Camray Deposit, Theano Point, Lake Superior, Slater Township (Township 29, Range 14) District of Algoma, modified after Lang (1949).

27 Uranium Deposits of Ontario

gangue minerals, and minor pyrite and galena are locally ene. Diamond drilling and underground work in 1953- present in the veins. E.W. Nuffield (1955) identified 1954 by Beaucage Mines Limited established reserves clausthalite (PbSe); klockmannite (CuSe) has also been on Newman Island which were reported in 1958 by Nova reported from the Ranwick Mine. At some localities, Beaucage Mines Limited to be 1 893 000 tons at an aver- namely the Bobcam and Ranwick properties, pitch- age grade of 0.049 percent U3O8 and 0.86 percent blende veins are locally present within the diabase dikes, Nb2O5, and 2 962 000 tons averaging 0.41 percent U3O8 as well as in the country rock (Nuffield 1955). and 0.69 percent Nb2O6, over a length of at least 325 m Early exploration and field relationships in the Mont- and width of up to 120 m2. The relatively small size of the real River area have been described by A.H.L. Lang deposit, metallurgical problems, and the ready availabil- (1949) and E.W. Nuffield (1950,1955) who ascribed the ity of uranium from Elliot Lake precluded mining the prop- uranium concentration to late-stage hydrothermal fluids erty. Only limited diamond drilling has been undertaken derived from diabasic magma. The magma presumably since 1954, and this has yielded little new information. dissolved uranium from the granitic and pegmatitic coun- Lumbers (1971) gave detail? of other showings in Lake try rock and redeposited it in available fractures. J.A. Nipissing. Robertson (1975), has suggested that the adjacent Ar- The Prairie Lake complex [7] north of Lake Superior chean-Late Precambrian unconformity may have acted was originally explored by Newmont Mining Corporation as the regional control. It is of interest that J. Satterly and of Canada in 1968-1970. Newmont Mining Corporation of D.F. Hewitt (1948) noted that the uranium was structurally Canada has reported uranium mineralization in 109 024 rather than genetically controlled by the diabase con- tons at 0.12 percent U3Oe over a width of 7 m and a mini- tacts. mum length 78 m. The poorly exposed complex was Road cuts on Highway 17 through high ground mapped by R.P. Sage etal. (1976). In 1976 (Sage and northeast of Theano Point reveal strongly kaolinized gran- Breaks 1976) exploration for apatite was undertaken by itic rock which is considerably less radioactive than the the International Minerals and Chemical Corporation. associated fresh rock. Weathering and leaching may Since 1976, the complex has been explored for uranium have removed uranium from a considerable volume of ur- by New Insco Mines Limited. During this period, the prop- aniferous rock and permitted its concentration in suitable erty was visited by Messrs. Fenwick and Scott, Sage, structural traps at or below the unconformity in a manner Robertson, and Ruzicka. General data are available in similar to that commonly invoked for the Athabasca de- summary articles by these geologists, and in relevant posits. Ground water may also have passed downdip press releases by the Northern Miner. Figure 13b shows through the overlying Lake Superior sandstone, oxidizing the field relationships. and leaching this granite-derived sandstone of its urani- Uranium in the Prairie Lake Complex occurs as uran- um. The uranium would have been redeposited downdip iferous pyrochlore and betafite at the contact between in the sandstone, this would correspond to the Wyoming nepheline syenite and an ijolite phase of the carbonatite roll front deposits. Some exploration has tested these hy- (Fenwick and Scott 1977). The best intersection obtained potheses, but has not yet been conclusive. is 14 m of 1.98 lbs U3O8/ton (0.1 percent) and 5.6 lbs No detailed scientific work has been done on the Nb2Osrton. However, the other holes contained substan- temperature of formation of vein material in the Montreal tially less, and insufficient mineralization has been iden- River area. Work on fluid inclusions, isotopes, and/or min- tified to warrant underground development. Two zones, B eral assemblages might well resolve whether these de- and C, have 1.54 lbs U3O6 across a width of 6.7 m, a posits are hydrothermal, as proposed by Nuffield, or length of 106.7 to 152.4 m, and a depth of at least 150 m. whether they are of the Athabasca type. A firm conclusion The other zone has grades ranging from 0.3 lbs across as to their genesis would strongly influence further ex- 4.6 m to 1.02 lbs across 3.5 m over a strike length of ploration in the area. 152.4 m (Northern Miner, October 13,1977). During 1977, two diatremes of alkalic affinity were Alkalic Complexes recognized at McKellar Creek and Deadhorse Creek between Prairie Lake and Lake Superior. These have been During magmatic differentiation, uranium and/or thorium described by several geologists, principally Fenwick and may be concentrated in alkalic rocks and the fenitic Scott, Sage, Robertson, and Ruzicka. The Deadhorse zones associated with them. In Ontario, alkalic rocks (see Creek deposit is presently being examined by Gulf Miner- Figures 1,2) lie along major fracture zones such as the als Limited. Grab samples assayed by the Provincial Lab- borders of the Kapuskasing structure [9]1 [11], and the oratory contain 0.003 percent to 0.004 percent U3OB. R.P. Lake Nipissing (15) graben system which is part of the St. Sage (1977) suggested that these diatremes and the in- Lawrence-Ottawa Valley System. Another linear system trusives at Slate Island, Prairie Lake, and Killala Lake are extends northward from Lake Superior. part of one regional structure, and lie carried out further In 1952, the fenite-bearing Manitou Islands complex field work on these alkalic rocks in 1978 (Sage 1978). (Figure 13a) in Lake Nipissing [15] was found to contain uraniferous pyrochlore in rocks composed either of potassic feldspar with sodic pyroxene or just sodic pyrox- 2 Subsequently, ore reserves were recalculated as being 3 596 120 tons grading 0.032 percent U3OS and 0.6275 percent Nb2O 1 Number in square brackets indicates location on Figure 2. (see Canadian Mines Handbook 1979-1980).

28 LEGEND

jwjftr no tt/wtotnctt

/V Unnhn rymmtn-tMrina rockt.

Itf'v'vl Jnpnnv*^#tMlfc ftUtfif ftnttt QOH' ljLjji tuning minvctrkHfmhtnHiw*.

F/gure 13a—Manitou /slancfe Complex, after Lumbers (1971).

Anomalous radioactivity has been recorded within some Phanerozok Deposits phases of the Coldwell Complex; at Craddock Cove a syenitic dike has been described by Lang and again by A number of minor uranium occurrences have been re- K.G. Fenwick and J.F. Scott (1977). The latter collected ported from the Phanerozoic sedimentary rocks of Ontar- two samples which yielded uranium contents of 0.42 and io. Interest has centred on March Township just west of 1.0lbU3Oeton. Ottawa where uranium-copper mineralization has been identified in Ordovician sandy dolomite and in the James As government and mining company work continues Bay [19] Lowlands where minor radioactivity and/or min- on alkalic complexes in Ontario, much will be learned eralization has been encountered in the Devonian Sex- about controls on mineralization and the mineralogy of tant Formation (Coral Rapids Project, Kerr Addison Mines deposits, particularly the relative distribution of uranium- Limited, Progress Report, May 1978; Assessment Files and thorium-bearing minerals. For examination of alkalic Research Office, Ontario Geological Survey, Toronto). complexes and associated fenite, a discriminating spec- Faint traces of radioactivity also occur in the Cretaceous trometer is essential; radioactive carbonate-bearing lignite (Robertson 1968a, 1975). In both localities, ura- veins adjacent to alkalic complexes at Firesand near nium is found in pegmatite in adjacent Precambrian rocks Wawa and Seabrook Lake near Highway 129 contain only and the occurrences in sedimentary rocks are ascribed thorium (Ruzicka 1977a and b, 1978; Robertson 1977). togroundwater. Several carbonate-vein occurrences near Bancroft, such as the Silver Crater (Satterly 1957), carry betafite or urani- March Township 1171 ferous pyroohlore and may have alkalic affinities. In 1972, experimental airborne gamma-ray spectrometry by the Geological Survey of Canada revealed an anoma- In general, the lack of good outcrop and the lack of lously high uranium content in the March Formation, a effective extraction processes for uranium in pyrochlore sandy dolomite (Grasty eta/. 1973). Subsequent ground have hindered exploration of the alkalic complexes. survey and laboratory work indicated 0.02 percent U30e,

29 Uranium Deposits of Ontario

GNEISS

O-. Dianond Drill Hoi* GNEISS O Showing * OraGmhFfoM

PnlrhUkt

Figure 13b— Prairie Lake Complex, after New Insco report in 1976. (See Files Assessment Research Office, Ontario Geological Survey, Toronto).

3.5 ppm Th, and chalcopyrite mineralization. The pres- rently has the two mining camps of Elliot Lake and Ban- ence of nearby uraninite-bearing pegmatite of Grenvillian croft, which are in separate Provinces of the Shield. age was recognized. Further studies by Steacy et at. These host about 13 percent of the free world's identified (1973) have failed to reveal the precise nature of the ura- and partly identified uranium resources in the economic nium mineralization, but have shown an association with and subeconomic categories, an amount of at least 430 hydrocarbon located on partings and other open spaces. 000 metric tons of uranium. The uranium ores, particularly V. Ruzicka and H.R. Steacy (1975) have stated that those at Elliot Lake, also contain substantial resources of impure psammite in the Ottawa embayment other than thorium. the March Formation also carries uranium mineralization. The principal types of uranium deposits in Ontario Ruzicka and Steacy (1975) also indicated that they had and corresponding areas of occurrence are as follows: 1) found vertical veinlets of hydrocarbon and coffinite in carbonatite or alkalic complex and associated fenite Grenvillian rocks near the Ordovician/Grenvilfe uncon- (Prairie Lake and Lake Nipissing); 2) alkalic volcanic rock formity near Dunrobin (see Robertson 1975). Kerr Addi- (Kirkland Lake); 3) pegmatite (Superior Province.and son Mines Limited carried out a surface-exploration pro- Grenville Province); 4) calc-silicate rock (Bancroft area); gram which included drilling, but little additional 5) pyritic quartz-pebble conglomerate (Southern Prov- information was obtained. Neither grade nor continuity ince); 6) polymictic conglomerate and semi-pelitic rocks was encouraging and the project was stopped. (Cobalt Embayment); and 7) various pitchblende deposits. Some pitchblende deposits are related to Late Pre- cambrian unconformities (Thunder Bay area) and others may be related to Late Precambrian diabase dikes (Mont- Conclusions real River). A third type of pitchblende deposit is associ- The geology of Ontario comprises Precambrian and ated with unconformities; these deposits are hosted by i) Phanerozoic rocks. The Precambrian (Canadian Shield) carbonate rock (March Township), ii) sandstone (James is subdivided into provinces and subprovinces on the ba- Bay Lowlands), iii) lignite (James Bay Lowlands), and iv) sis of stratigraphic and structural history. Ontario cur- 30 TABLE 9 I CLASSIFICATION OF URANIUM DEPOSITS IN ONTARIO.

MAGMATIC DEPOSITS 1. Carbonatite bodies and alkBlic complexes, including fenites. 2. Calcalkaline extrusive rocks.

, MAGMATIC - METAMORPHIC DEPOSITS 3. Pegmatite: a) red zoned b) redunzoned c) white 4. Calcsilicate (skarn) rocks and pyroxenite.

SEDIMENTARY (DETRITAL DEPOSITS) 5. Quartz-pebble conglomerate: a) pyritt-uranium-thorium b) iron oxide-thorium 6. Polymictlc conglomerate, semipelitic rocks.

CIRCULATING MINERALIZED SOLUTIONS* 7. a) Pitchblende with simple mineralogy (Athabasca type). b) Pitchblende with multi-metal mineralogy (Bohemia type). c) Mineralization of unspecified nature, generally related to an unconformity and found in argillite, greywecke, sandstone, carbonate rock, and lignite. d) Uraninite-caJcite-apatite-f luorite veins.

UNCLASSIFIED DEPOSITS 8. Usually small occurrences about which little is known.

* largely equivalent to the vain deposits of the OECD (1977) and of Robertson (1975), or the "hydrogenic deposits" of McMillan (1977).

semi-pelitic rock of Middle and Upper Precambrian age Uranium, because of its chemistry and mobility may (Cobalt Embayment and Thunder Bay). These various occur in several different modes in one area, and is an pitchblende deposits comprise the "hydrogenic" depos- excellent element for studying metallogenesis and metal- its of R.H. McMiHan {1977.1978). logenic provinces. The classification scheme for Ontario's uranium de- Geological features reflect major changes in physics posits used in this paper (Figure 2; Table 9) is a simple and chemistry and are prime controls on the distribution one derived from J.A. Robertson (1975). It is generally of uranium deposits. These are: geological Province and compatible with the scheme used by international groups Subprovince boundaries, including unconformities, major for reporting uranium resources, see Organization for faults, higher metamorphic grades, domain boundaries Economic Co-operation and Development (1977,1979). related to quartz monzonite batholiths, and the distribu- In general, the author favours more detailed and complex tion of carbonate rocks. schemes, F.Q. Barnes and V.J. Ruzicka (1972) modified For each deposit type, a systems analysis would from Ruzicka (1975) or McMillan (1977, 1978), relating identify parameters critical to: 1) source area; 2) transpor- uranium deposits to geological processes and environ- tation, 3) deposition; 4) modification; and 5) preservation: ments. The simple scheme is particularly suited to classif- to which could be added, 6) extraction. ying data in government files much of which is either old The foregoing parameters may be used to identify or was submitted as proof of work done, and was not sub- areas of high exploration potential and to attempt re- mitted specifically as geological data. source evaluation on a broad scale. Provincial and fed- Only red unzoned pegmatites (Bancroft) and pyritic eral government maps, reports, assessment files, sum- quartz-pebble conglomerate (Elliot Lake-Agnew Lake) maries of field work, and the Provincial-Federal Uranium have supported production. White pegmatite, elkalic Reconnaissance Programme provide a wealth of data on complexes, calc-silicates, and "unconformity-related" which exploration personnel may base their programme deposits have had considerable exploration activity. strategies. Ontario has many geological environments fa-

31 Uranium Deposits of Ontario

TABLE 10| URANIUM RESOURCES {1979) 1OOOTONNES U.

Reasonably Assured Estimated Additional S/kgV Measured Indicated Inferred Prognosticated WORLD 'cost' JUS <80 18501 14803 80 -131) 740 970 <130 2590 49802 2450 CANADA 'price' $C <125 76 215 139 223 370 147 125-175 4 20 16 79 358 279 <175 80 235 1S5 953 302 728 426 ONTARIO 'price' $C < 166 (1978) 49 125 76 553 246 428 182 <175 365 544 179 Footnotes 1 Column indicates reasonably assured resources. 3 Column indicates total uranium resources. 3 Column indicates estimated additional resources.

vourable for uranium concentration, some of which are thanks are due to Dr. H. Little (retired) and Dr. V.J. Ruz- also favourable for thorium. Viability of individual deposits icka of the Federal Uranium Appraisal Group, with whom largely depends on the price/cost ratio which, in turn, de- an integrated study of Ontario uranium deposits has been pends upon grade, tonnage, and amenability to extrac- conducted since 1973. Many results from joint visits to tion. Under present conditions, deposits with an overall properties have already been published by Dr. V.J. Ruz- grade in excess of 11b of recoverable U3Oa per ton (0.05 icka in Summaries of Activities by the Geological Survey percent) are of economic interest, whereas deposits be- of Canada. tween 0.5 and 1 Ib U3O8 per ton are of lesser interest. Preparation of this paper has been greatly assisted Many people have been dazzled by the recent major in- by Tanya Abolins, Jan Michalik, Ulrihe Rybak, Guy Ken- creases in the price of uranium, but mining costs have drick, and Iva Sherrett of the Ontario Geological Survey. also risen markedly and cut-off ore grades consequently have not dropped appreciably, particularly for new areas and even new deposits in old areas. Appendix Since this paper was written additional data on Uranium Acknowledgments Resources has been published - (OECD 1979; EMR This review has drawn heavily on earlier reviews and 1979). Table 10 has been compiled from such data and other papers. Several references in the following bibliog- may be compared with Table 1. Whilst resources in On- raphy contain references to additional articles. The au- tario (after allowing for production) have shown little thor is greatly indebted to his colleagues in the Ontario change, new discoveries are reflected in the world data Ministry of Natural Resources, of the Geological Survey reflecting discoveries in Canada (Saskatchewan), South and the Regional Staff, and to geologists with the Geolog- Africa, and Central and South Africa. There remains con- ical Survey of Canada, the mineral-exploration industry, siderable potential for further discoveries in these areas the academic community, and a large number of both and in Australia and U.S.A. Comparison of Table 1 and 10 Canadian and foreign geologists with whom there have also permits an estimate of the current discovery rate been numerous discussions and field trips. Particular over and above production. logical Survey. Miscellaneous Paper 82,235p References Berning. J.. Cooke, R., Hiemstra, S.A., and Hoffman, U. 1976: The Roessing Uranium Deposit, South West Africa; p.351- Adams, F.D., and Barlow, A.E. 368 in Economic Geology, Volume 71, No. 1. 1910: Geology of the Haliburton and Bancroft Areas, Province of Bottrill.T.J. Ontario; Geological Survey of Canada, Memoir Number 6, 1971: Uraniferous Conglomerates of the Canadian Shield; p.77- 419p. 83 ^Geological Survey of Canada. Paper 71 -1 A, 279p. Arnold, R.6. Breaks. F.W.. and Bond, W.D 1954: A Preliminary Account ol the Mineralogy and Genesis of 1978: English River Gneiss Belt; Oral Presentation at Ontario Ge- the Uraniferous Conglomerate of Blind River, Ontario; Un- ological Survey Workshop, February 2.1978. published M.A.Sc. Thesis, University of Toronto. Breaks. F.W., Bond, W.D.. and Denver Stone. Ayres, L.D. 1978: Preliminary Geological Synthesis of the English River Sub- 19?0: Setting Net Lake Area, District of Kenora (Patricia Portion); province, Northwestern Ontario and its Bearing upon Min- Ontario Department of Mines, Pialiminary Map P.538, Scale eral Exploration: Ontario Geological Survey, Miscellaneous ' inch to V2 mile. Paper MP 72, 55p Accompanied by Map P1971, Scale Ayres, L.D., Lumbers, S.B., Milne. V.G.. and Robeson. D.W. 1:253440 1971a: Explanatory Text, Legend. Diagrams, Title, Scale torOn- Bright. E.G. tario Geological Map; Ontario Department of Mines and 1974: Cavendish and Anstruther Townships, Peterborough Northern Affairs. Map 2196. Completion 1970. County, Soufhern Ontario; p.139-145 in Summary of Field 1971b: Ontario Geological Map, Southern Sheet; On'ario De- Work by the Geological Branch, Ontario Division of Mines. partment of Mines and Northern Affairs, Map 2197, Scale 1 Edited by V G. Miine, D.F. Hewitt, K.D. Card, and J.A. 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33 Uranium Deposits of Ontario

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Kustra, Ontario Geological Survey Miscellaneous Paper 71. 1956: The Algom Mines-Geology; Western Miner and Oil Review. 142p. Volume 29, Number 7. p.66-68. Ferris, C.S., and Rudd, CO. 1957: Pronto Mine; p.324-339 m Structural Geology of Canadian 1971: Brannerite: It's Occurrences and Recognition by Micro- Ore Deposits, Canadian Institute of Mining and Metallurgy, probe; Quarterly Journal of the Colorado School of Mines, Special Paper, Volume 2. Volume 66. Number 4. Joubin, F.R. Fowler, A.D. 1954: Uranium Deposits of the Algoma District. Ontario; Cana- 1978: Grenville Province Uraniferous Granites; Oral Presentation dian Institute of Mining and Metallurgy Transactions, Vol- at Short Course on Genesis of Uranium Ore, McGill Univer- umes?, p.431-437. sity, January 16-20,1978. 1960: Comments Regarding the Blind River (Algoma) Uranium Franklin, J.M. Ores and Their Origin; Economic Geology, Volume 55, 1978: Uranium Mineralization in the Nipigon Area, Thunder Bay p.1751-I756. District; Ontario Geological Survey of Canada, Paper 78, Joubin, F.R. and James, D.H. PartA,p.275-282. 1956: The Algoma District; p.84-86 in Canadian Mining Journal. Goodwin, A.M., Ambrose, J.W., Ayres, L.D., Clifford, P.M., Cur- Volume 77, June 1956,156p. rie, K.L, Ermanovics. I.M., Fahrig, W.F., Gibb. R.A., Hall. D.H., 1957: Algoma Uranium District; p.305-317 in Structural Geology Innes, M.J.S., Irvine, T.N., MacLaren, A.S., Norris, A.W., and Pet- of Canadian Ore Deposits, Canadian Institute of Mining and r,, F.J. Metallurgy, Volume 2.

34 Kaiman. S., and Horwood. J. McDowell, J.P. 1976: An Unusual Thucholite from Elliot Lake, Ontario; Paper 1957: The Sedimentary Petrology of the Mississagi Quartzite in Presented at Geological Association of Canada, Annual the Blind River Area; Ontario Department of Mines, Geolog- Meeting, Edmonton, May 19-21. ical Circular 6,31 p. Accompanied by 3 Figures. Kimberley, M.M. McMillan. R.H. 1978: Short Course in Uranium Deposits: Their Mineralogy and 1977: Metaltogenesis of Canadian Uranium Deposits: A Review Origin; Edited by M.M. Kimbertey; Mineralogical Associa- in Geology, Mining and Extractive Processing of Uranium, tion of Canada, 521 p. Edited by M.J. Jones; Proceedings of a Symposium Spon- sored by the Institute of Mining and Metallurgy, London, Kileen, P.G. January 17-19,1977. 1967: Gamma-Ray Spectrometer Survey, Elliot Lake; p. 149 in 1978: Genetic Aspects and Classification of Important Canadian Report of activities, Part A, May-October 1966; Canada Uranium Deposits: p 187-204 in Short Course in Uranium Dept. Energy, Mines and Resources, Geological Survey of Deposits: Their Mineralogy and Origin, Editor, M.M. Kim- Canada, Paper 67-1, Part A, 221 p. berley, Mineralogical Association of Canada, 521 p. Lang,A.H. Mair. J.A., Maynes, A.D., Patchett. J.E., and Russell, R.D. 1949: The Camray Uranium Discovery; Canadian Mining and 1960: Isotopic Evidence on the Origin and Age of the Blind River Metallurgy Bulletin, Volume 42, Number442, p.68-72. Uranium Deposits; Journal of Geophysical Research. Vol- 1952: Canadian Deposits of Uranium and Thorium; Geological ume 65, Number 1,p.341-348. Survey of Canada; Economic Geology Series, Number 16, Meyn, H.D. 1st Edition. 1972: The Proterozoic Sedimentary Rocks North and Northeast Lang, A.H., Griffith, J.W., and Steacy, H.R. of Sudbury Ontario; p.129-145 in Huronian Stratigraphy 1962: Canadian Deposits of Uranium and Thorium; Geological and Sedimentation, Edited by G.H. Young; Geological Survey of Canada; Economic Geology Series, Number 16, Association of Canada Special Paper Number 12,271 p. 2nd Edition. Morton. R.D. Leahy, E.J. 1978: The Identification of Uraniferous Minerals; p.141-183 in 1973: Diamond Drilling in the Huronian Supergroup, Sault Ste. Short Course in Uranium Deposits: Their Mineralogy and Origin, Edited by M.M. Kimberley; Mineralogical Associa- Marie-Elliot Lake Area, Algoma District, Ontario: Ontario Di- tion of Canada, p.521. vision of Mines Open File Report 5093, with Map P.753. Nuffield, E.W. Le Conte, L 1950: Preliminary Report on the Geology of Part of Township 29. 1847: On Coractte, a New Ore of Uranium; American Journal of Range XIV, District of Algoma; Ontario Department of Science, Volume 3, p.173-175. Mines, Preliminary Report p.1950-1955. Little, H.W. 1954: Brannerite from Ontario, Canada; American Mineralogist, 1972: Uranium in Canada; in Report of Activities, Part A, April to Volume 39, p.520-522. October, 1971, Geological Survey of Canada, Paper Num- 195S: Geology of the Montreal River Area; Ontario Department of ber 72-1, Part A, p.88-90. Mines Volume 64, Part 3,32p. Accompanied by Map 1955- Little, H.W., Smith, E.E.N., and Barnes, F.Q. 1. Scale 1 inch to 1/i mile. 1972: Uranium Deposits of Canada; Twenty Fourth Session, In- Organization for Economic Co-Operation and Development ternational Geological Congress, Montreal, Canada, Gui- 1977: Uranium: Resources, Production, and Demand; Organiza- debook, far Field Excursion C67,64p. tion for Economic Co-operation and Development, 136p. Logan, W.E. 1979: Uranium:.Resources. Production, and Demand; Organiza- 1863: Chapter 4; p.50-66 in The Geology of Canada; Geological tion for Economic Cc-Operation and Development. 195p. Survey of Canada, 983p. with Accompanying Atlas, Text Patchett, J. 42p.,and4Maps. 1959: Some Contributions to the Mineralogy of the Blind River Lovell, H.L., and Ploeger, F.R. Ore Conglomerate; Talk Given to Mineralogical Association of Canada. Not published. 1977: 1976 Report of the Kirkland Lake Resident Geologist; 1960: A Study of the Radioactive Minerals of the Uraniferous p.77-94 in Annual Report of the Regional and Resident Ge- Conglomerate, Blind River Area; Unpublished Ph.D. Thesis. ologists 1976, by the Ontario Geological Survey, Edited by University of Toronto. C.R. Kustra, Ontario Geological Survey Miscellaneous Pa- Patchett, J.E., and Nuffield. E.W. per 71,142p. 1960: Studies of Radioactive Compounds, X-Ray Synthesis and Lumbers. S.B. Crystallography of Brannerite; p.483 in Canadian Mineralo- 1964: A Preliminary Report on the Relationship of Mineral Depos- gist, Volume 6, Part 4.554p. its in Intrusive Rocks and Metamorphism in Part of the Pienaar, P.J. Grenville Province of Southeastern Ontario; Ontario Depart- 1963: Stratigraphy, Petrology, and Genesis of the Elliot Lake ment of Miner, Preliminary Report, 1964-4,37p. Group, Blind River, Ontario, Including the Uraniferous Con- 1967: Geology &u Mineral Deposits of the Bancroft-Madoc glomerate; Geological Survey of Canada, Bulletin 83,140p. Area; p.13-30 in Guidebook to Geology and Parts of East- Porter, Arthur em Ontario and Western Quebec; Geological Association 1978: A Race Against Time; If ;iim Report on Nuclear Power in of Canada Annual Meeting, Kingston 1967. Ontario; Royal Commission on Electric Power Planning, 1971: Geology of the North Bay Area, Districts of Nipissing and Queen's Printer for Ontario. 227p. Party Sound; Ontario Department of Mines and Northern Af- Pretorius, D.A. fairs, Geological Report 94,104p. 1966: Conceptual Geological Models in the Exploration for Gold 1975: Pembroke Area, District of Nipissing and C. ,nty of Ren- Mineralization in the Witwatersrand Basin; Symposium on frew; p.91-93 in Summary of Field Work 1975, by the Geo- Mathematical Statistics and Computer Application in Ore logical Branch Edited by V.G. Milne, D.F. Hewitt, K.D. Card, Valuation, Johannesburg; South African Institute of Mining and J.A. Robertson, Ontario Division of Mines Miscellane- and Metallurgy 1966, p.225-275. ous Paper 63,15Bp.

35 Uranium Deposits of Ontario

1975: The Depositional Environment of the Witwatersrand Goldfi- by V.G. Milne. O.L. White, R.B. Barlow, and J.A. Robertson, On- elds: A Chronological Review of Speculations and Obser- tario Geological Survey, Miscellaneous Paper 62,235p. vations; Minerals Science Engineering, Volume 7, Number 1978b: Uranium Deposits in Ontario; p.229-280 in Short Course 1.P.18-47. in Uranium Deposits: Their Mineralogy and Origin, Edited Pryslak, A.P. by M.M. Kimberley; Mineralogical Association of Canada, 1976: Geology of the Bruin Lake - Edison Lake Area, District of 521 p. Kenora: Ontario Division of Mines, Geological Report 130, Robertson, J.A., Frarey, M.J., and Card, K.D. 61 p. Accompanied by Maps 2302 and 2303, Scale 1 inch 1969: The Federal Provincial Committee on Huronian Stratigra- to 14 mile (1:31 680), and 1 Chart. phy: Progress Report; Canadian Journal of Earth Sciences, Ramdohr, P. Volume 6, p.335-336. 1957: Die "Pronto Reakttion"; Neues Jahrbuch Mineralogie Mon- Robinson, S.C., and Hewitt, D.F. atsh., Jahrg. 1957, Heft 10-11, p.217-221. 1958: Uranium Deposits of Bancroft Region, Ontario; Paper Pre- 1958: New Observations on the Ores of the Witwatersrand in sented to the 2nd International Conference on the Peaceful South Africa and Their Genetic Significance: Geological Uses of Atomic Energy, Geneva, Switzerland, September Society South Africa, Annexure to Volume 61. 1-13: Atomic Energy of Canada Limited. Richardson, K.A., Killeen, P.G., and Charbonneau, B.W. Roscoe, S.M. 1975: Results of a Reconnaissance Type Airborne Gamma Ray 1957: Geology and Uranium Deposits. Quirke Lake - Elliot Lake, Spectrometer Survey of the Blind River - Elliot Lake Area; Blind River Area. Ontario; Geological Survey of Canada, p.133-135 in Geological Survey of Canada. Paper 75-1, Paper 56-7,21 p. Accompanied by 3 Figures. Part A. 602p. 1959a: On Thorium-Uranium Ratios in Conglomerate and Asso- Robertson, D.S. ciated Rocks Near Blind River, Ontario: Economic Geology, 1962: Thorium and Uranium Variations in the Blind River Camp; Volume 54, p.511-512. Canadian Mining Journal, p.58-65. 1959b: Monazile as an Ore Mineral in Elliot Lake Uranium Ores; 1974: Basal Proterozoic Units as Fossil Time Markers and Their Canadian Mining Journal, July 1959. p.65. Use in Uranium Prospection; p.3 in Formation of Uranium 1969: Huronian Rocks and Uraniferous Conglomerates in the Ore Deposit. Proceedings of a Symposium in Athens 6-10 Canadian Shield: Geological Survey of Canada. Paper 68- May 1974, International Atomic Energy Agency Vienna 40.205p. 1974. 1973: The Huronian Supergroup, a Paleoaphebian Succession Robertson, D.S. and Steepland, N.C. Snowing Evidence of Atmospheric Evolution in Huronian 1960: Blind River Uranium Ores and Their Origin; Economic Ge- Stratigraphy and Sedimentation; p.31-47 in Geological ology, Volume 55, p.659-694. Association of Canada, Edited by G.M. Young, Special Pa- Robertson, J.A. per Number 12. p.271. 1967: Recent Geological Investigations in the Elliot Lake - Blind Roscoe, S.M.. and Steacy, H.R. River Uranium Area, Ontario; Ontario Department of Mines, 1958: On the Geology and Radioactive Deposits of the Blind Miscellaneous Paper 9,31 p. Accompanied by 8 Figures. River Region; Geological Survey of Canada. Paper Pre- 1968a: Uranium and Thorium Deposits of Northern Ontario; On- sented to the Second International Conference on the tario Department of Mines, Mineral Resources Circular 9, Peaceful Uses of Atomic Energy. Geneva, Switzerland. 106p. September 1-13. Atomic Energy of Canada Limited. 1968b: Geology of Township 149 and Township 150; Ontario De- Rowe. fl.B. partment of Mines, Geological Report 57,162p. 1952: Petrology of the Richardson Radioactive Deposit. Wilber- 1969: Geology and Uranium Deposits of the Blind River Area, force. Ontario: Geological Survey of Canada, Bulletin 23, Ontario; Canadian Institute of Mining and Metallurgy Bulle- 22p. tin, Volume 62, Number 686, p.619-634. Ruzicka. V. 1970: Geology of the Spragge Area, District of Algoma; Ontario 1975: New Sources of Uranium? Types of Uranium Deposits Department of Mines, Geological Report 76,109p. Presently Unknown in Canada p. 13-20 in Uranium Explora- 1971: A Review of Recently Acquired Geological Data. Blind tion 75. Geological Survey of Canada, Paper 75-26,71 p. River- Elliot Lake Area; Ontario Department of Mines, Mis- 1976: Assessment of Some Canadian Uranium Occurrences: cellaneous Paper 45,35p. p.341-342 inGeological Survey of Canada. Report of Activ- 1973: A Review of Recently Acquired Geologic Data. Blind ities, Part A. Paper 76-1 A, 522p. River-Elliot Lake Area; p. 169-198 in Huronian Stratigraphy 1977a: Estimation of Undiscovered Uranium Resources in Cana- and Sedimentation, Edited by G.M. Young; Geological da; p 39-56 in Uranium Resource Evaluation. Energy, Association of Canada, Special Paper Number 12.271 p. Mines, and Resources, Canada, Report ER 77-1. 1975: Uranium and Thorium Deposits of Ontario; Ontario Division 1977b: Assessment of Selected Uranium Occurrences and of Mines, Preliminary Maps P.969 Northwestern Sheet, Areas Favourable for Uranium Mineralization in Canada; P.970 West Central Sheet, P.971 East Central Sheet. P.972 p.27-29 inGeological Survey of Canada. Report of Activi- Southern Sheet, Scale 1 inch to 16 miles. Compilation 1973, ties, Part A, Paper 77-1 A. 527p. 1974. 1977c: Conceptual Models for Uranium Deposits and Areas Fa- 1976: Tht Blind River Uranium Deposits: The Ores and Their Set vourable for Uranium Mineralization in Canada; p.17-25 in ting; Ontario Division of Mines Miscellaneous Paper 65. Geological Survey of Canada, Paper 77-1 A, 527p. 45p. 1978: Evaluation of Selected Uranium Bearing Areas in Canada; 1977: Uranium Deposits of Ontario; p.185-187 in Summary of p.269-274 in Geological Survey of Canada, Current Re- Field Work 1977 by the Geological Branch. Edited by V.G. search Part A, Paper 78-1 A, 558p. Milne, O.L. White, R.B. Barlow, and J.A. Robertson, Ontario Ruzicka, V., and Steacy, H.R. Geological Survey Miscellaneous Paper 75,20Bp. 1975: New Radioactive Occurrences in the Precambrian West of 1978a: Uranium Deposits of Ontario; p.194-197 in Summary of Ottawa; p.234 in Geological Survey ol Canada. Paper 75 Field Work, 1978, by the Ontario Geological Survey, Edited PartA,6O2p.

36 1976: Some Sedimentary Features of Conglomeratic Uranium Stockwell, C.H. Ore from Elliot Lake. Ontario; p.343-346 in Geological Sur- 1964: Fourth Report on Structural Provinces, Orogenies, and vey of Canada, Paper 76-1 A, 522p. Time-Classification of Rocks of the Canadian Precambrian Sage, R.P. Shield; p.1-2 /nGeological Survey of Canada, Paper 64-17, 1975: Carbonatite-Alkalic Complexes; p.69-79 in Summary of Part11,29p. Field Work 1975 by the Geological Branch, Edited by V.G. Tanton.T.L. Milne, D.F. Hewitt, K.D. Card, and J.A. Robertson, Ontario 1931: Fort William and Port Arthur and Thunder Bay Map-Areas. Division of Mines Miscellaneous Paper 63,158p. Thunder Bay District, Ontario; Geological Survey of Cana- 1977: Carbonatite-Alkalic Complexes; p.69-79 in Summary of da. Memoir 167,222p. Field Work by the Ontario Geological Survey, Edited by 1948: Radioactive Nodules in Sediments of the Sibley Series, Ni- V.G. Milne, O.L. White, R.B. Barlow, and J.A. Robertson, pigon, Ontario; Transactions of the Royal Society of Cana- Ontario Geological Survey Miscellaneous Paper 75,208p. da, Volume 42, Series 3, Section 4. p.69-75. 1978: Radioactive Diatremes North of Lake Superior; p.53-66 in Theis.N.J. Summary of Field Work, 1978 by the Ontario Geological 1973: Comparative Mineralogy of the Quirke No. 1 and New Survey, Edited by V.G. Milne, O.L. White, R.B. Barlow, and Quirke Mines, Rio Algom Mines Limited, Elliot Lake, Ontar- J.A. Robertson, Ontario Geological Survey Miscellaneous io; M.Sc. Thesis, Queen's University, Kingston, Ontario. Paper 82,235p. 1976: Uranium Bearing and Associated Minerals in Their Geo- Sage, R.P., Bathe, D., Wright, W., Chamois, P., and Shewbeidge, chemical and Sedimentological Context, Elliot Lake, Ontar- K. io; Unpublished Ph.D. Thesis, Queen's University, King- 1976: Prairie Lake Carbonatite. District of Thunder Bay; Ontario ston, Ontario. Division of Mines, Preliminary Map P.1O7O, Scale 1 inch to 1978: Mineralogy and Setting of Elliot Lake Deposits; p.331-338 200 feet, Geology 1975. in Short Course in Uranium Deposits: Their Mineralogy and Sage, R.P., and Breaks, F.W. Origin, Edited by M.M. Kimberiey. Mineralogical Associa- 1976: Operation Pickle Lake; Patricia, Kenora, and Thunder Bay tion of Canada, 521 p. Districts, Ontario; Ontario Division of Mines, Open File Re- 1979: Uranium Bearing and Associated Minerals in Their Geo- port 5180. chemical and Sedimentological Context, Elliot Lake. Ontar- Satterly.J. io; Geological Survey of Canada. Bulletin 304,50p. 1955: Radioactive Mineral Occurrences in the Vicinity of Hawk Thomson, J.E. and Richard Lakes; Ontario Department of Mines, Geologi- 1960: Uranium and Thorium Deposits at the Base of the Huro- cal Circular Number 1, 6p. nian System in the District of Sudbury; Ontario Department 1957: Radioactive Mineral Occurrences in the Bancroft Area; of Mines, Geological Report 1, 40p. Accompanied by 10 Ontario Division of Mines, Volume 65, Part 6,181 p. Accom- Charts. panied by 21 Figures in Map Case. Thorpe, R.I. Satterly.J., and Hewitt, D.F. 1963: The Radioactive Mineralogy of the Ore Conglomerate at 1948: Report on a Pitchblende Occurrence at Theano Point, Panel Mine, Blind River, Ontario; Unpublished M.Sc. The- Lake Superior, Ontario; Ontario Department of Mines, Pre- sis, Queen's University, Kingston, Ontario. liminary Report 1948-4. VanSchmus.W.R. Scott, W.R. 1965: The Geochronology of the Blind River-Bruce Mines Area, 1976: Uranium Occurrences in the Kenora Mining Division; Un- Ontario, Canada; Journal of Geology, Volume 73, p.755- published Open File Report, Kenora Regional Geologist's 780. Office. Wallace, H. Smith, E.E.N. 1978: Slate Falls Area, District of Kenora; p.4-9 in Summary of 1974: Review of Current Concepts Regarding Vein Deposits of Field Work, 1978, by the Ontario Geological Survey, Edited Uranium in Formation of Uranium Ore Deposits; Interna- by V.G. Milne, O.L. White, R.B. Barlow, and J.A. Robertson, tional Atomic Energy Agency, Vienna, p.515-529. Ontario Geological Survey, Miscellaneous Paper 82,235p. Steacy, H.R., Boyle, R.W. Charbonneau, B.W., and Grasty, R.L. Wolff, J.M. 1973: Mineralogical Notes on the Uranium Occurrences at South 1977: No. 21 Kaladar Area, Counties of Frontenac and Lennox March and Eldorado, Ontario; p.103-105 m Geological Sur- and Addington; p.118-121 /nSummaryof Fieldwork, 1977. vey of Canada, Paper 73-1, Part B, 215p. by the Geological Branch, Edited by V.G. Milne, O.L. White, Steacy, H.R., and Kaiman, S.S R.B. Barlow, and J.A. Robertson, Ontario Geological Sur- 1978: Uranium Minerals in Canada: Their Description, Identifica- vey, Miscellaneous Paper 75,208p. tion and Reid Guides; p.107-140 in Short Course in Ura- Wynne-Edwards, H.R. nium Deposits: Their Mineralogy and Origin, Edited by 1972: The Grenville Province P.263-334 in Variations in Tectonic M.M. Kimbertey; Mineralogical Association of Canada, Styles in Canada; Edited by R.A. Price and R.J.W. Douglas. 521 p. Geological Association of Canada Special Paper Number