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ONTARIO DEPARTMENT OF MINES

SUMMARY OF FIELD WORK, 1964 by the GEOLOGICAL BRANCH

Edited by

J. E. THOMSON

P.R. 1964-6 No charge November, 1964 Publications of the Ontario Department of Mines are obtainable through the Publications Office, Department of Mines, Parliament Buildings, Toronto 5* Ontario, Canada.

Preliminary Report P.R. 1964-6, paper-bound only: No Charge

Orders for publications should be accompanied by cheque or money order payable in Canadian funds to Provincial Treasurer, Ontario. Stamps are not acceptable. TABLE OF CONTENTS Page

Introduction by J.E. Thomson ...... l Outline map showing location of field parties, 1964 ...... 2 Muskratdam Lake Area, Patricia Portion, District of x© Kenora (No.l ) by L.D. Ayres ...... 3 West Lake St. Joseph Area, Patricia Portion, District of Kenora (No.2) by P.M. Clifford ...... 5 West Minnitaki Lake Area, District of Kenora (No. 3) by F. J. Johnston ...... 7 Geochemical Investigations, Northwestern Ontario (No. 4) by A. M. Goodwin ...... 8 Fort Frances Area, District of Rainy River (No. 5) by J. C. Davies ...... 11 Entwine Lake Area, District of Kenora (No. 5) by J. C. Davies ...... 12 Steep Rock Iron Area, District of Rainy River (No. 6) /^ by R. Shklanka ...... 13 , East Lac des Mille Lacs Area, District of Thunder Bay (No. 7) by Leslie Kaye ...... 15 Lac des Iles Area, District of Thunder Bay (No. 8) by E.G. Pye ...... 17 Black River Area, District of Thunder Bay (No. 9) by V. G. Milne ...... 20 Dayohessarah Lake Area, District of Algoma (No. 10) by K.G. Fenwick ...... 22 Townships 27 and 28, Range XIII, District of Algoma (No. 11) by P. E. Giblin ...... 24 Townships of Proctor and Lewis and parts of Serpent River Indian Reserve (l.R.7), District of Algoma (No. 12) by J.A. Robertson ...... 26 Waters Township, District of Sudbury (No. 13) by K.D. Card ...... 28 Leinster, Tyrone and Kitchener Townships, District of Sudbury (No. 13) by K.D. Card ...... 30 Halcrow and Denyes Townships, District of Sudbury (No. 14) by J.F. Donovan ...... 31 Murphy Township, District of Cochrane (No. 15) by S.A. Ferguson...... 33 Ogden, Deloro and Shaw Townships, District of Cochrane (No. 16) by H.D. Carlson ...... 35 Nighthawk Lake Area, District of Cochrane (No. 17) by E. J. Leahy ...... 37 Powell and Cairo Townships, District of Timiskaming (No. 18) by H.L. Lovell...... 39 Flavelle, Gross, Blain, Willison, Davidson, and Sharpe Townships, Englehart River Area, District of Timiskaming (No. 18) by H.L. Lovell...... 40

- 111 - TABLE OF CONTENTS Page

Willet, Roadhouse, Lawson Townships, Elk Lake Area, District of Timiskaming (No. 19) by B.E. MacKean ...... 42 North Half of South Lorrain Township, District of Timiskaming (No. 20) by W. H. Mcilwaine ...... , ...... 43 Lake Nipissing Area, Districts of Nipissing, Parry Sound and Sudbury (No. 21) by S.B. Lumbers ...... 45 Madoc Township, County of Hastings (No. 22) by D.F. Hewitt ...... 48 Parry Sound - Huntsville Map Area (No. 22) by D.F. Hewitt ...... 49 Pleistocene Geology of the Thornhill and Bolton Areas (No. 23) by P.F. Karrow ...... 50 Pleistocene Geology of the London - St. Thomas and Port Stanley Areas (No. 24) by A. Dreimanis ...... 52 Marl, Diatomite and Peat Moss in Ontario (No. 25) by G.R. Guillet ...... 53 Resident Geologist©s Office, Port Arthur by E.G. Pye ...... 54 Resident Geologist©s Office, by H.D. Carlson ...... 56 Resident Geologist©s Office, Cobalt by Robert Thomson ...... 57 Resident Geologist©s Office, Sault Ste. Marie by P.E. Giblin ...... 58

- iv - SUMMARY OF FIELD WORK, 1964

by the

GEOLOGICAL BRANCH

ONTARIO DEPARTMENT OF MINES

INTRODUCTION by J. E. Thomson1

The Geological Branch had 25 Geological survey parties, totalling 114 persons, in the field during the summer of 1964; also 7 resident geologists did field work in their respective districts. A brief summary of the results of these surveys is given in this report. Emphasis is placed on the economic aspects of the investigations in the hope that the information might be of assistance to those who are engaged in mineral exploration in Ontario. The location of each field party and the name of each party leader and resident geologist is shown on the outline map of the province on page 2.

Part A of this summary contains reports by the leaders of the geological survey parties. Part B deals with recent activities in some of the resident geologists districts.

Most of the detailed mapping in Precambrian field areas (Nos. 2, 3* 8, 9, 11, 12, 1J, 14, 15, 16, 17, 18, 19, 20, 22) was ^one at the scale of one inch to 4 mile, for publication at one inch to 2 mile. Geological maps covering reconnaissance surveys (Nos. l, 5, 7, 10 ) and Pleistocene geology (Nos. 23 and 24) will be published at the scale of one inch to one mile. Detailed maps of the Steep Rock mining camp (No. 6) will be published at the scale of one inch to 1,000 feet.

Uncoloured preliminary geological maps of most of the areas will be published during the winter of 1964-1965; these maps will contain marginal notes. A few preliminary reports will also be issued. Notices of the release of these preliminary maps and reports will be mailed to all persons and organizations on the Ontario Department of Mines notification list.

Eventually coloured maps and detailed reports will be published to cover most of these field projects.

Requests for publications, and inquiries about publications, should be addressed to the Publications Office, Department of Mines, Parliament Buildings, Toronto 2, Ontario, Canada.

Chief Geologist, Geological Branch, Ontario Department of Mines, Parliament Buildings, Toronto. GEOLOGICAL BRANCH ADMINISTRATION

Director —ME Hurst Chief Geologist — J E Thomson Chief, Publications — J Satterly

PATRICIA

RESIDENT GEOLOGIST OFFICES

Kenora — J. C. Davits fort Arthur — E. G. Pye Timmins — H D. Carlson — W. S. Savage Cobalt— R. Thomson Sault Ste. Marie - P E. Giblin Sudbury — K. D. Card

1964 LOCATION OF FIELD PARTIES GEOLOGICAL BRANCH, ONTARIO DEPARTMENT OF MINES

Block River Area...... V G Milne

Townships 27, 28, Range XIII

Nighthawk Lake Are Resident Geologist

Territorial District boundary PART A. REPORTS ON GEOLOGICAL FIELD WORK

No. l MUSKRATDAM LAKE AREA

PATRICIA PORTION, DISTRICT OF KENORA by L.D. Ayres

Location; The map-area comprises 1,700 square miles and is bounded by latitudes 53 0 10 T and 53 0 35S and by longitudes 91 0 00© and 92 0 30 f . Reconnaissance mapping was begun in 1963 and was completed in 1964. The centre of the area is about 145 miles north-northwest of Pickle Lake and about 195 miles north-northeast of Red Lake.

Mineral Exploration; Intermittent exploration has been carried out for at least thirty years, but poor rock exposure makes exploration difficult. At the present time, there are no recorded claims, but during the field season, several prospectors were active in the area.

General Geology; An east-trending, Precambrian metavolcanic- metasedimentary belt, previously mapped in the vicinity of Munekun Lake, Muskratdam Lake, and the Severn River west of Muskratdam Lake (O.D.M. Preliminary Map P.213), ends abruptly at latitude 92 0 20©W. At its west end the belt is 12 miles wide and is separated from a north- trending metavolcanic belt near the Rottenfish River by a zone of granitic rocks three miles wide. The north-trending belt has a maximum width of three miles and has been mapped for a strike length of 15 miles; neither end of the belt was found. This belt may extend south to join a metavolcanic belt previously mapped at Sandy Lake. North of Muskratdam Lake, the east-trending belt bifurcates; the north branch is three miles wide and extends at least five miles northwest of the main part of the belt. Other unmapped areas on Map P. 213 are underlain by granitic rocks.

At the west end of the Muskratdam Lake belt, three stratigraphic units have been recognized; from bottom to top these are mafic metavolcanic group, felsic metavolcanic group, and metasedimentary group. The felsic metavolcanic group is variable both in lithology and in thickness. Tuff, lapilli tuff, and agglomerate predominate; flow rocks form domical masses and narrow layers within the pyroclastic deposits. Near the top of the sequence tuff and lapilli tuff of subgreywacke composition are intimately interlayered with narrow felsic flows and with arkose derived from this tuff and from felsic flows. This arkose-tuff unit grades upward into greywacke, arkose, and slate of the metasedimentary group. Thick conglomerate, slate, and iron formation units are found in the felsic metavolcanic group; impure marble and calc-silicate rocks occur near the top of the group.

Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 4 -

The Rottenfish River belt is composed predominantly of mafic metavolcanics. A narrow felsic agglomerate, tuff, and flow unit is found near the west side of the belt. Narrow iron formation units are common. Metagabbro sills, dikes, and irregular bodies have been intruded into the metavolcanic-metasedimentary sequences. Sills, up to 1.5 miles thick, are the most common type of intrusion.

Complex, commonly concordant batholiths composed of varying amounts of quartz diorite, hornblende-biotite trondhjemite, biotite trondhjemite, porphyritic hornblende-biotite granodiorite, porphyritic biotite granodiorite, equigranular biotite granodiorite, biotite quartz monzonite, leucocratic quartz monzonite, and pink pegmatite have intruded the metavolcanic-metasedimentary-metagabbroic sequences. Contacts between the various phases of the batholiths range from sharp to gradational. Syenodiorite and diorite are locally found at the margins of the batholiths and also underlie a circular area, two miles in diameter, east of Rottenfish Lake. North of Muskratdam Lake white, locally tourmaline-bearing pegmatite is found in the north branch of the metavolcanic belt. A small quartz monzonite stock has intruded metavolcanics near the junction of these two belts. Late gabbro and diabase dikes are rare.

Extensive Pleistocene clay, sand, and gravel deposits, and Recent swamp and muskeg cover most of the bedrock; outcrops are not abundant. Structural Geology; A medial anticline and two flanking synclines are the major structural features at the west end of the Muskratdam Lake belt. Complexities in the structure have been caused by refolding about a northeast-trending axis and by at least two major faults.

The f old pattern in the Rottenfish River belt is unknown. A major north-northeast-trending shear zone forms the southeast boundary of the belt; shearing and mylonitization extend at least 1,000 feet into the granitic rocks. The shear zone has been traced southward through Rottenfish Lake where the zone of shearing in granitic rocks is at least 2,000 feet wide. A poorly defined, north-trending major fault zone appears to have moved the west side of the belt several miles north relative to the east side. Numerous minor faults have offset these fault zones.

Economic Geology; In 1937 gold was reported in the Rottenfish River belt, but no evidence of this occurrence was found during the field season. Quartz veins, lenses, and stockworks containing rare pyrite and chalcopyrite are found in all rock types; grab samples collected by the author from 105 veins gave upon assay only trace amounts of gold. - 5 -

Disseminated pyrite, pyrrhotite, and rare chalcopyrite were observed in many parts of the area, but no concentrations of sulphide minerals were found.

Magnetite-bearing, lean iron formation, in units up to 100 feet thick, was found in both the Rottenfish River and Muskratdam Lake belts. A large magnetic anomaly occurs along the Rottenfish River belt. In the northern part of the belt compass deviations averaging 30 degrees were observed across the entire belt. East of the belt compass deviations were noted for one mile into areas underlain by granitic rocks; compass deviations also occur over granitic rocks west of the belt. During most traverses across the north part of the belt, two maxima, producing 180 degree deviations were observed. The anomaly is probably produced by magnetite-bearing iron formation although, during the reconnaissance survey, no large iron formation outcrops were observed near the maxima.

No. 2 WEST LAKE ST. JOSEPH AREA

PATRICIA PORTION, DISTRICT OF KENORA

by P.M. Clifford1

Location: The map-area is bounded by longitudes 91 0 09©W. and 91 0 45 T W., and by latitudes 50 0 53 t 05"N. and 51 0 05©N., and is about 690 square miles in area. The centre of the area is about 65 miles northeast of Sioux Lookout.

Mineral Exploration; In May and June of 1964, SELCO, an exploration subsidiary of Selection Trust, conducted ground geophysical studies on anomalies revealed by aeromagnetic survey. No geologic work was carried out.

General Geology; The area shows two gross geologic divisions. Almost all the northern two-thirds consists of granitic material, which may be massive, gneissic, migmatitic, or xenolithic; the composition ranges from alaskite to quartz diorite, but not with any apparent systematic distribution. Some extensive sheets of meta-andesite remain intact in this granitic material, as well as a large mass of hornblende- biotite rock, perhaps derived from an ultrabasic parent. The southern third of the area contains rocks older than the granite. Volcanic rocks include andesitic varieties which may be in the form of flows, or pillowed and autobrecciated. There are also rhyolitic and dacitic flows and pyroclastic rocks, lying above the andesites. On the eastern edge of the area the volcanic rocks are

Department of Geology, McMaster University, Hamilton, Ontario. - 6 - about 5*000 feet thick, but they thin steadily to the west (almost zero at the Cat River), passing beyond the western boundary, presumably to link with volcanic sequences to the west. Overlying these volcanic rocks is a group of sedimentary rocks of arkose and greywacke affinities, derived from the volcanic rocks. Within these rocks bands of magnetite, hematite, chert (iron formation) appear; also pebble beds derived from volcanic rocks, sedimentary rocks and iron formations. These rocks total perhaps 2,500 feet in thickness at the eastern boundary thinning to about 1,000 feet at the western boundary. The iron formation becomes insignificant where the volcanic rocks are least prominent. A second sedimentary sequence, now represented by biotitic schists and gneisses, is exposed along the entire southern boundary of the area. These rocks are stratigraphically partly older than, and partly equivalent to, the volcanic rocks and derived sedimentary rocks mentioned above. These schists and gneisses are commonly invaded by pegmatitic material. Structural Geology; A major syncline, whose core lies within the sedimentary rocks derived from the volcanic rocks, plunges gently east in the eastern half of the area; it may reverse plunge in the western half. Its axial plane is approximately vertical, striking east-west, where not disturbed by later shear folding of local signi ficance. The northern limb of this major fold lies in the volcanic sequence, or has been obliterated by the post-deformational granites. The southern limb involves the biotitic schists and gneisses which probably also are involved in a major anticline lying parallel to, and south of, the syncline. Within their common limb, these two folds have suffered extensive shearing and fracturing, yielding a shear zone at least 20 miles along its strike from east to west, and about 0.5 miles wide. No notable post-shear mineral deposits were seen in this zone. Economic Geology: Magnetite-hematite occurs throughout the southern section of the area, but only in the southeast corner is it sufficient ly rich to warrant attention. There, Lake St. Joseph Iron, Limited, hold 14 of their total 72 claims on the iron formation of Lake St. Joseph. Estimated reserves for all claims are 240,000,000 tons of concentrating-type material, averaging 35 percent Fe. The iron-bearing minerals appear to have been derived from the volcanic rocks. Their present distribution is due to the effects of triple folding. Sulphide mineralization is widespread, particularly in the volcanic rocks, but nowhere reaches significant proportions in outcrop. The pegmatites along the southern edge of the area are rich in felspar, muscovite and tourmaline. Intensive examination of some - 7 - might show workable amounts of felspar or mica, and might reveal minerals such as spodumene, which has been found in pegmatites in adjacent areas.

No. 3 WEST MINNITAKI LAKE AREA

DISTRICT OF KENORA by F.J. Johnston^

Location: The map-area comprises about 72 square miles and consists of Pickerel township and an unnamed township area to the east, south of Jordan township. Highway No. 72 crosses Pickerel township and terminates at Sioux Lookout about 15 miles north of the area.

Mineral Exploration; Prospecting for gold and base metals has been carried out in this area since the late 1890 f s. The latest major activity in the area followed the discovery of gold and development work at Newlund Mines Ltd. in Echo township in 1941- In 1956 a limited amount of diamond-drilling for copper and gold was carried out along the northeast part of Pickerel Arm by -Rio Canadian Exploration Ltd. There has been no mineral production from the area.

General Geology: The oldest rocks in the area consist of thick sequences of intercalated volcanic and sedimentary rocks. The vol canic rocks consist mainly of basic to intermediate lavas, pillow lavas, agglomerates, and tuffs and locally acid flows, agglomerates, and tuffs. The sedimentary rocks are mainly greywacke and slate, with local occurrences of conglomerate, arkose, quartz-biotite schist, iron formation, and chlorite schist.

Sill-like bodies of quartz and feldspar porphyry occur mainly in the volcanic and sedimentary rocks on the large peninsula south of Pickerel Arm and in the western part of Pickerel Township north of Highway 72. Dikes and sills of granite and granodiorite occur in the volcanic rocks in the vicinity of Kabikwabik Lake. Structural Geology; Numerous northeast-trending shear zones occur in the rocks adjacent to Pickerel Arm and in the area west and northwest of Highway 72. Top determinations in the volcanic and sedimentary rocks indicate isoclinal folding.

^Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 8 -

Economic Geology:

Gold:- Most of the prospecting for gold has been confined to the area adjacent to, and west and northwest of Pickerel Arm. The rocks of this area have been more highly sheared than elsewhere. Mineral ized quartz veins carrying gold values occur as fracture fillings and lit-par-lit veins in the sedimentary rocks, volcanic rocks, and porphyries.

Interesting gold values have been reported but development has not gone beyond the trenching, limited diamond-drilling, and, on some of the old prospects, the shallow shaft stage.

Iron Formation; A persistent band of iron formation, 30 feet to over 300 feet wide, occurs in the sedimentary rocks near the contact with a greenstone belt south of Minnitaki Lake. The iron formation consists of thin layers of magnetite with rare thin laminae of hematite interlayered with cherty quartzose bands, chloritic schist, and dark slates. Some sections as much as 10 feet wide contain an estimated 20 to 30 percent magnetite but nowhere was the grade or width observed to be sufficient to warrant present economic consideration. Another lean iron formation band occurs near the west boundary of the area near mileage 23 on Highway No. 72. This band of iron formation contains local concentrations of pyrite and pyrrhotite.

Sulphides; Small amounts of chalcopyrite and malachite occur in shear zones in a quartz-feldspar porphyry body near the narrows of Pickerel Arm. The property was drilled in 1956 by Rio Canadian Exploration Ltd. but was abandoned.

Local concentrations of pyrite and pyrrhotite occur in the volcanic rocks throughout the area. Test pits have been sunk along a pyritic shear zone on the northwest shore of Pickerel Arm just north of the Jordan-Pickerel township line.

No. 4 GEOCHEMICAL INVESTIGATIONS, NORTHWESTERN ONTARIO by A.M. Goodwin

Introduction; Selected greenstone belts in Ontario are being inves tigated by stratigraphic and chemical means in order to determine (l) the general volcanic setting of the belts, (2) the chemical com-

-"-Geologist, Ontario Department of Mines, Parliament Buildings, Toronto, Ontario. - 9 - positions and sequences of volcanic components, and (3) relation ship of mineralization to rock type and structure. Volcanic rocks of the greenstone belts are generally distributed in sequences, lower basic volcanic rocks being overlain by upper acid rocks. In general, gold and base metal deposits display a preference for the highly siliceous rocks. Detailed examination of a number and variety of greenstone belts should reveal metal distribution patterns of significance to exploration activities in Ontario.

Location of Area: The Lake of the Woods greenstone belt in the District of Kenora was examined during the 1964 field season and latter part of the 1963 field season. The belt is 150 miles long and 50 miles broad. It extends from the Ontario-Manitoba inter-provincial boundary on the west to Wabigoon Lake on the east and from the Trans-Canada highway on the north to Nestor Falls on the south. The seven parts of this region examined and sampled in detail are, from west to east: (l) Shoal Lake; (2) north-central part of Lake of the Woods; (3) Sioux Narrows-Long Bay; (4) Kakagi-Rowan Lakes; (5) Upper Manitou Lake; (6) Eagle Lake; and (?) Wabigoon Lake. Mineral Exploration; In the past, a small amount of gold and indus trial minerals has been produced at a number of small properties. Former producers include the Mikado, Olympia and Duport gold mines at Shoal Lake, Gold Rock mine at Upper Manitou Lake, Horseshoe mine at Regina Bay of Lake of the Woods, Redeemer gold mine in the Dyrden- Wabigoon area, and the Eagle Lake soapstone quarry at Eagle Lake. With the exception of exploratory diamond-drilling on the property of Kenora Prospectors and Miners Limited at Shoal Lake, there was no significant exploration in the region during the 1964 field season so far as known. General Geology: Basic to acid volcanic rocks and associated clastic sedimentary rocks have been folded and intruded by younger gabbro, diorite and granite intrusions. At least three superimposed sequences of basic flows and intermediate to acid pyroclastic rocks including rhyolite are present. Erosion during and following volcanic accumulation has cut down deeply into the volcanic pile, particularly in the central and east parts of the region. As a result, highly siliceous volcanic rocks are relatively scarce. In their place appear great thicknesses of impure arkose and quartzite. At Kakagi Lake, at least three differentiated gabbro sills are present in the volcanic sequence. Structural Geology; The rocks have been highly folded about axes with a bearing of N.?0 0 E. The main anticlines follow the large granite intrusions, and the main synclines follow the intervening volcanic- sedimentary belts. Thus, the principal anticlines cross (l) the north part of Lake of the Woods, (2) Aulneau Peninsula, and (3) the - 10 -

large granite mass situated between Eagle and Manitou lakes. The principal synclines cross (l) the south-central part of Lake of the Woods, (2) Kakagi Lake, (3) Upper Manitou Lake, and (4) Eagle Lake. Many subsidiary folds with the same trend are present. All folds plunge steeply west or vertical. Shearing is conspicuous in many parts of the region as in the north-central part of Lake of the Woods and at Eagle Lake. A prominent zone of shearing extends at least 100 miles in a great arcuate structure from Long Bay, of Lake of the Woods through Dogpaw, Cameron, and Straw lakes to Manitou stretch, Lower Manitou Lake and Manitou straits of Upper Manitou Lake.

Economic Geology: A number of gold deposits associated with acid intrusions are under active exploration at Shoal Lake. Significant gold values have been obtained in this area suggesting that sub stantial mineralization may be present.

Some disseminated sulphides are present in differentiated basic sills at Shoal Lake, particularly in the lower (eastern) part of the sills. Although no valuable metals were noted in the field or determined by spectrographic methods in grab samples, a more systematic search using geophysical and geochemical methods might be rewarding.

Attention is drawn to the extensive shear zone referred to above extending from Long Bay, Lake of the Woods to the Manitou lakes. This zone is marked on the ground by sheared rock, rusty weathering carbonate and quartz stringers. Detailed search along it may reveal significant mineralization. The only large mass of highly siliceous volcanic rocks appears to lie in the northeast part of Lake of the Woods between Andrew Bay and Hay Island on the east and the vicinity of Louella Island of the Western Peninsula on the west. The association of siliceous rhyolite and porphyry dikes and sills exposed on several islands in the vicinity is considered to be favourable. - 11 -

No. 5 FORT FRANCES AREA

DISTRICT OF RAINY RIVER by J.C. Davies1

Location; The area includes the townships of Dance, Griesinger, Burriss, Miscampbell, Devlin, Crozier, Woodyatt and Roddick, the town of Fort Frances, and Indian Reserves No. l, No. 16D, No. 18B, and No. 18C. It adjoins to the west the area mapped by A. C. Lawson in 1913, and to the east the Emo area (O.D.M., Map 1954-2).

Mineral Exploration; Very little exploration has been undertaken in the area partly because it has long been known as a "granitic area" and partly because of the heavy overburden in the southern parts. With the publication of aeromagnetic maps some interest has been shown in the iron formation.

General Geology; The sedimentary and volcanic rocks which have been mapped in the areas to the east and west underlie the southern part of the Fort Frances area, and occur discontinuously in the northern part of the area. These include greywacke, minor conglomerate, iron formation, tuff, agglomerate and flows. Gabbro and related basic rocks underlie the south half of Burriss township and much of Devlin township; granodiorite and related acid rocks predominate in Dance, Griesinger and Miscampbell townships and Indian Reserve 16D. Diabase dikes cut all of the above rock types.

Structural Geology; The major structural picture appears to be that of a north-northwest trending anticline upon which have been super posed two east-west trending synclines and an anticline. The picture is based largely on aeromagnetic interpretation because of scarcity of outcrop, and evidence for distinguishing anticlines from synclines is admittedly very poor.

An interesting feature is an east-west "fault" zone about 2- mile wide which lies near the north limit of the map-area. Small scale slip planes of the order of 2-inch apart, with subsequent alteration and recrystallization, give the rock a pseudo-sedimentary appearance.

Economic Geology; A number of small sulphide showings have been found in the farm land area. These contain pyrite, pyrrhotite and chalcopy rite, but none sampled by the writer contained more than a trace of gold. Specks of molybdenite were noted at one place near the "fault" zone in Dance township.

Outcrops of iron formation indicate that the iron-rich bands

Resident Geologist, Ontario Department of Mines, 203 Main St. S., Kenora, Ontario. - 12 - constitute a small percentage of the total sedimentary material of which they are a part. Near the west side of Boffin Lake, however, magnetic anomalies occur over many hundreds of feet and it is possible that higher grade portions of economic interest are present.

No. 5 ENTWINE LAKE AREA DISTRICT OF KENORA

by J.C. Davies

Introduction and Location; Near the end of the field season two weeks were spent in the reconnaissance survey of magnetically anomalous area in the vicinity of Entwine Lake. The lake is about 45 miles south of Dryden and 50 miles northeast of Fort Frances. Excessive rainfall did not permit completion of the survey.

Mineral Exploration: Some staking occurred in the area following publication of aeromagnetic map 1152G, but further work apparently was not undertaken.

General Geology; A tadpole-shaped intrusion, the tail of which consists of pinkish diorite and the head of which is dominantly anorthositic gabbro, lies within an area of gneissic granodiorite. A narrow discontinuous band of basic volcanic rocks up to 800 feet wide occurs between the basic intrusion and the granodiorite. At the centre of the anorthositic gabbro is a small area of altered ultrabasic rock, possibly a biotite peridotite. Along the northwest edge of the anorthositic gabbro is porphyritic monzonite, and a very similar rock appears to have intruded the central area of basic and ultrabasic rocks. Structural Geology; The peridotite, gabbro, diorite and monzonite are probably all part of a single intrusive complex. Banding in the gabbro is rare, but is approximately concentric about the peridotite. Lineation of minerals in the "tail" of diorite suggests a plunge to the east. Radial faulting in the northwest section is interpreted as limiting the porphyritic monzonite. Regional faulting in a north- northeast direction has resulted in considerable displacement. One such fault, readily apparent on the aeromagnetic map, displaced the south contact of the intrusion about 2,000 feet. A displacement of

-^Resident Geologist, Ontario Department of Mines, 203 Main St. S., Kenora, Ontario. - 13 - similar magnitude occurs on a parallel fault l 3/4 miles to the east.

Economic Geology; A little disseminated pyrite and pyrrhotite was noted in a few places near the outer edge of the gabbro. Dissem inated pyrite, pyrrhotite and chalcopyrite occur in the basic volcanic rocks which lie adjacent to the intrusion.

No. 6 STEEP ROCK IRON AREA

DISTRICT OF RAINY RIVER by R. Shklanka X

Introduction; The Ontario Department of Mines in co-operation with Steep Rock Iron Mines Limited and Caland Ore Company Limited is undertaking a detailed geological survey of the Steep Rock Iron area. The area to be covered is approximately 6.5 miles square and contains the former Steeprock Lake and the town of Atikokan. The project, initiated in 1964, is to be continued into 1965. Location: During 1964, field work was concentrated in the eastern part of the area, north of the Canadian National Railway mainline, including the town of Atikokan and to the east of it, and south of Caland Ore Company©s open pit operations in Falls Bay. This roughly corresponds to the southwest part of Schwenger township. Mineral Exploration; The area was the site of exploration since the 19th century culminating with the discovery of iron ore beneath Steeprock Lake in 1938. In addition to iron, attention has been directed to gold and iron pyrites.

Patented claims virtually blanket the area.

General Geology; Most of the area is underlain by a Keewatin-type assemblage of intermediate to basic volcanic tuffs, agglomerates, and flows with lesser amounts of greywacke, arkose, phyllite, conglomerate, and rhyolite. In addition, a dolomitic unit and a younger "ash rock" unit, regarded as part of the "Steeprock group or series" by previous workers, appear to be conformably inter bedded within this predominantly volcanic sequence. Pyritic, ferruginous chert, chert, and banded magnetite-chert units were observed intermediate to the dolomite and "ash rock". A conglomerate previously believed to directly underlie the dolomite and mark an unconformity at the base of the "Steeprock group or series" is

Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 14 - probably separated from the dolomite by a succession of volcanic rocks. In the south part of the area "Seine or Couchiching" meta- sediments, consisting of micaceous schists, arkose, phyllite, and conglomerate occur in structural discordance with the Keewatin- type succession to the north. A granitic batholith borders the volcanic and sedimentary rocks to the east. Previous workers regarded the "Steeprock group or series" as unconformably overlying this granitic body. Field evidence obtained by the writer to date favours an intrusive relationship. If so, the "Laurentian" age commonly assigned to this granite is not justified. Numerous early basic dikes intrude the sedimentary and volcanic rocks but pre-date granitic intrusion. Late basic dikes intrude the granitic, sedimentary, and volcanic rocks. Structual Geology: The structural geology is exceedingly complex. The rocks are highly sheared and faulted. At least three periods of faulting and two periods of folding are suspected. Southwest- plunging folds dominate the structural picture. The folds and faults repeat the stratigraphic succession throughout the area. Economic Geology; The hematite-goethite deposits being mined occur stratigraphically between the dolomite and "ash rock" units. Overlying and underlying members and basic dikes that transect the ore have been altered within the vicinity of the ore deposits. The dolomite and "ash rock" units that contain the ore deposits in Falls Bay follow the southeast arm of Steeprock Lake. Mapping has extended these units southward,around the granitic tongue in the southeast part of the area to the C.N.R. mainline. Drilling in 1943 by the Frobisher Exploration Company out lined a deposit of hematitic material under the southeast part of Strawhat Lake. The deposit occurs between dolomite and "ash rock" units near the core of an isoclinal fold. The axial trace of this fold extends in a northwesterly direction and closure is to the southeast. Associated pyrite deposits were investigated by drilling in 1902 and 1909. - 15 -

No. 7 EAST LAC DES MILLE LACS AREA

DISTRICT OF THUNDER BAY by Leslie Kaye

Location: The area mapped, about 300 square miles, lies within latitudes 48 0 42 f and 48 0 56©N., and longitudes 90 0 05 f and 90 0 38©W. Access to Lac des Mille Lacs is direct from Highway 17, which passes by the northeast arm of the lake, or by a motor road from the highway to the centre of the map-area, which is about 65 miles northwest of Port Arthur.

Mineral Exploration: Intermittant activity during the last 60 years has not disclosed any orebodies in the area. A previous geological map of the area by T. L. Tanton was published by the Geological Survey of Canada in 1938 (Map 432A). In 1953, the Canadian Pacific Railway mapped and prospected part of the volcanic- sedimentary belt. In 1962, the Phelps-Dodge Corporation Limited did a limited amount of diamond-drilling, geophysical surveying, and geological mapping. Iron formation on The Abitibi Power &1 Paper Co. Ltd. property east of Lac des Mille Lacs, has attracted considerable interest. A few patented, and recently staked claims are in good standing.

General Geolgoy: The bedrock is of Precambrian age. Thick and extensive deposits of Pleistocene sand, gravel, and boulders cover most of the area north and east of Lac des Mille Lacs. The north part of the area is underlain by amphibolitic gneisses and biotite granite. A central belt of Keewatin-type metavolcanics, about three miles wide, tapers to an end eastwards and is delimited on the south by banded metasediments and lit-par-lit migmatite gneisses, respectively equivalent to the Seine and Couchiching rocks of most previous writers. The metavolcanics are comprised of basic to intermediate massive flows, pillowed lavas, rhyolitic flow-breccias and agglomerates, and acid tuffs. These rocks have undergone low-grade regional meta morphism. The acid volcanic rocks form a distinctive mappable lithologic unit. In the southeast of the belt, a band of pillowed

Department of Geology, Carleton University, Ottawa, Ontario. - 16 -

lavas with interbedded massive flows, about one mile wide, was traced along a strike of 12 miles.

Quartz porphyry, and basic to ultrabasic rocks ranging from diabase, feldspathic hornblende gabbro, serpentinous gabbro to peridotite, intrude the metavolcanics. Remnants of basic stocks occur as xenoliths within the northern granite.

The Seine-type metasediments, which are stratigraphically below the metavolcanics, are comprised of biotite-quartz paraschists, and slates, cherts and tuffaceous (?) schists, which exhibit a well-defined sedimentary layering towards the top of the succession. A conglomeratic zone, up to 50 feet thick, and traced along a strike of nine miles, is locally in gradational contact with tuffs of the metavolcanic belt. Eastwards, as a result of a lateral facies change, conglomerate lies stratigraphically below sedimentary magnetite iron formation and garnet-hornblende schist.

A biotite granite stock, roughly circular in outcrop and two miles in diameter, intrudes the metasediments in the east part of the area.

Lit-par-lit migmatite gneisses occupy the south part of the map-area and are mainly intruded by white, grey, pink, and red granites, syenite, and leucopegmatite.

Structural Geology; A defined major isoclinal syncline, slightly overturned to the south has produced tectonic thickening and repetition of lithologic units. The trace of the axial-plane is parallel to bedding foliation, and lies within the pillowed lava band which is flanked by acid volcanic rocks. Along the hinge-area of the fold, where axial-plane cleavage is most strongly developed, the rocks are highly schistose. Minor-scale open folds and associated lineations, imposed upon bedding foliation in the metasediments and on the axial-plane foliation in the metavolcanics, are evidence of a later period of folding which involved both groups: minor-scale open folds were also recognized in the lit-par-lit migmatite gneisses. Near the west boundary of the map-area, foliation and pillowed lavas strike north. A shear zone along a fault trends N.30 0 E. in the north-central part of the map-area. A major fault follows the volcanic-sedimentary contact at the west end of the area, truncates the major synclinal fold, and continues eastward between Seine-type metasediments and the lit-par-lit migmatite gneisses. An apparent left-hand, or south- side east, horizontal displacement of at least 12 miles is indicated.

Economic Geology: Within the main pillowed lava band, shear zones are mineralized with disseminated pyrite, pyrrhotite, and minor chalcopyrite - 17 -

On the north and south limbs of the major syncline, brecciated and schistose volcanic rocks are similarly mineralized. In two locations, pillow-rims one inch thick are completely replaced by pyrite. Several small gossans are exposed along the shoreline of Lac des Mille Lacs.

Favourable areas for future exploration are located in the vicinity of the contact of the pillowed lavas and the acid volcanic rocks. Gold values have been reported from a zone of quartz-carbonate veins within the metavolcanic band, in the area north of Bolton Bay. This zone, which is up to 50 feet wide, was traced by the writer over a length of 880 feet. Numerous quartz veins,occurring in the metavolcanics, contain sparse mineralization.

Minor disseminated molybdenite in quartz veins, and in association with pyrrhotite in a carbonatized breccia zone in rhyolite porphyry, occurs along the northeast shore of Lac des Mille Lacs.

Except for the magnetite iron formation, the metasediments do not contain any appreciable mineralization.

No. 8 LAC DES ILES AREA DISTRICT OF THUNDER BAY by E. G. Pye 1

Location; The area lies about 55 miles west-northwest of the lakehead cities of Port Arthur and Fort William. It is bounded by north latitudes 49 0 07 f 30" and 49 0 15©00", and by west longitudes 89 0 17 t OO" and 89 0 43 f OO", and covers approximately 180 square miles. The east portion of the area is crossed by the Spruce River road (Highway No. 800). Mineral Exploration; The first account of exploration in the area was submitted by F. H. Jowsey Limited. On the strength of an aeromagnetic survey made in 1958, this company acquired 80 claims covering the north end of Lac des Iles. Subsequent geophysical work resulted in the finding of several conductive zones, and early in 1959 these were tested by diamond-drilling,

Resident Geologist, Ontario Department of Mines, 179 S. Algoma St., Port Arthur, Ontario. - 18 - but without indicating anything of commercial value. The area then lay dormant until 1963 when prospector G. Moore discovered copper- nickel sulphide mineralization south of Lac des Iles. A large block of claims was acquired immediately by Gunnex limited, and during late 1963 and early 1964 an intensive exploration program was undertaken. In all eight sulphide deposits, some containing significant amounts of platinum and palladium, were located and sampled. General Geology: The oldest rocks in the area are Archean metavolcanics, which make up a northeast-trending belt, up to 4 miles wide, that extends from Legris Lake to Poshkokogan Lake. They include massive greenstone and amphibolite, pillow lava, metadiabase, dacite, rhyolite, and associated tuffs and agglomerates. Overlying these rocks stratigraphically, and bordering them on the southeast, is a thick deposit of metasediments, chiefly conglomerate and massive and slaty greywackes. The metavolcanics and metasediments were not found in contact, and although the former appear to be the older, the relationships are not precisely known.

Younger than the metavolcanics and metasediments are bodies of gabbro and associated ultrabasic rocks. The most important of these bodies is at Lac des Iles. In plan it is a crescent-shaped mass, with a length, in a north direction, of ?2 miles, and a maximum width, where it underlies the lake, of 2 3/4 miles. It can be divided into three distinct parts: (1) a north part, semicircular in outline, made up mainly of pyroxenite bordered by an irregular and discontinuous rim of peridotite and subordinate serpentinite; (2) a central, roughly circular part, up to 2 miles across, made up mainly of peridotite and serpentinite with little or no pyroxenite; and (3) a south-projecting crudely wedge-shaped part, 32 miles in length, made up chiefly of gabbro, anorthositic gabbro, and anor thosite. Layered structures in widely separated outcrops were found to trend southeast to northeast and to dip steeply, and indicate the possibility the mass has been disturbed and rotated from its original crustal position. Large batholithic masses of granitic rocks intrude and completely enclose the Lac des Iles igneous complex, and flank the Archean metavolcanics and metasediments to the east. They are mainly medium-grained, massive, pale grey to pink varieties, with both biotite and hornblende as essential mafic constituents. They are considered tentatively to be of Algoman age and to have been emplaced during the Kenoran orogeny at the close of the Archean.

The youngest rock in the area is diabase of Keweenawan age. It occurs as both flat sheets (Logan sills) and dikes. The sheets are up to at least 200 feet thick. They are found mainly at the - 19 -

level of the present surface, and erosional remnants form high, irregular-shaped hills bounded, in places, by steep escarpments. The dikes, which are vertical or near-vertical in attitude, were found associated with the sheets in the east part of the area. One strikes north across Max Lake; a second extends northwest from the intersection of Block Creek and the Spruce River road (Highway No. 800).

Structural Geology; The Archean layered rocks in the area dip vertically to steeply north or south. Grain gradations and cross bedding in the metasediments, and pillow structures in the meta- volcanics, indicate that they have been isoclinally folded, with axial planes trending northeast parallel or nearly parallel to the formations. Lineations provided by the parallelism of prismatic minerals, and by elongated fragments in conglomerate and agglomerate, show that these folds pitch 25-40 0 N.E. Few faults were recognized during the field mapping. Transverse and oblique structures, along which any appreciable movement has occurred, are rare; strike faults, which may be represented by several prominent linear topographic depressions, are not apparent because of the general absence of displaced north-trending lithographic units. Economic Geology: The most important mineral deposits that have been found in the area are the sulphide deposits discovered by G. Moore and W. Baker on the property of Gunnex Limited south of Lac des Iles. These deposits, eight in number, are made up of small amounts (5-10 percent) of pyrite and copper and nickel sulphides disseminated throughout gabbro and anorthositic gabbro. The largest and possibly the most important zone, the "C" zone, is exposed in outcrops and trenches over a length of 450 feet and widths up to 150 feet. Samples of mineralized material from 4 trenches indicated an average grade of 0.32 percent copper, 0.31 percent nickel, and 0.032 and 0.299 ounces per ton of platinum and palladium, respectively. Two diamond-drillholes were bored at opposite ends of the exposed area to test the zone. One hole intersected 250 feet of mineralized rock that was found, according to the company, to average 0.11 percent copper, 0.12 percent nickel, 0.013 ounces per ton platinum, and 0.105 ounces per ton palladium; the second hole intersected 302.2 feet of mineralized rock that was found to average 0.11 percent copper, 0.13 percent nickel, 0.015 ounces per ton platinum and 0.128 ounces per ton palladium. The mineralized zone appears to strike east or slightly north of east. The dip and limits of the zone, however, have not been determined. In the east part of the area the metavolcanics and metasediments - 20 -

in places are cut by narrow quartz and quartz-carbonate veins. Chip samples from several of these were assayed for precious metals, but only traces of gold and silver were found.

A deposit of massive sulphides outcrops along the Spruce River road about 2 mile south of the latter©s intersection with Poshkokagan Creek. It consists of pyrite and pyrrhotite in schistose tuff and agglomerate, and is exposed across a width of 15 feet. It strikes N.70 0 E. and dips 70 0 S. A similar massive sulphide deposit, about 2 mile to the northeast, is at least 30 feet wide and can be traced continuously for 300 feet. It also strikes N.70 0 E. and may be the extension of the first. A channel sample taken by F. Jolliffe^ in 1933 was found to contain only traces of gold and silver and to be barren of copper, nickel, and platinum. Jolliffe^ reported a third sulphide deposit, 2 feet

1. F. Jolliffe, "Block Creek Map-Area, Thunder Bay District, Ontario, "Geol. Surv. Canada., Summ. Rept., 1933, pt. D, p. 15d. 2. Idem.

wide and also barren of precious metals, close to the south shore of a small lake along Max Creek.

No. 9 BLACK RIVER AREA

DISTRICT OF THUNDER BAY by V.G. Milne1

Location; The area lies between latitudes 48"45 1 and 48 0 55 f and longitudes 85 0 49 f and 86 0 05 f in the District of Thunder Bay. (The centre of the area is about 22 miles south-southwest of the Manitouwadge mining camp.) Highway 614 to Manitouwadge runs north- south along the eastern margin of the area, and the southern limit of the map is about 4 miles north of the junction between this highway and Highway 17. About 150 square miles were maped. Mineral Exploration: Since discovery of the orebodies in the Manitouwadge area in 1953 the whole district has been regarded with interest. Within the map-area, claims have been staked and restaked

Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 21 -

at various times, mostly along a belt extending northeast from about Valley Lake to east of Highway 614. In 1962, Mcintyre Porcupine Mines Ltd. surveyed anddrilleda 52-claim area enclosing a Cu-Ni showing just east of Summers Lake on Highway 614. In 1963, a minor amount of drilling was done by Mining Corporation of Canada Ltd. in the area between Amwri Lake and the Black River about 2 to l mile east of the river. In late 1963 T. and W. Kusins uncovered a Pb-Zn showing between the Black River and Valley Lake, about 3/4 mile west of the river.

General Geology: A belt of biotite-quartz-feldspar paragneisses, hornblendic metatuffs and agglomerates, and metavolcanic hornblende gneisses extends generally east-northeast from south of Valley Lake through Pinegrove and Amwri lakes. The belt is about 12 miles wide in the west and widens to about 6 miles on the east mainly due to an increase in the quantity of metavolcanic gneisses on the north side of the belt. The flow rocks are predominantly mafic hornblende gneisses of formerly pillowed basaltic or andesitic character. The rocks of this belt are intruded by granites, feldspar porphyry and amphibolitic metagabbro dikes. Most of the western two-thirds of the area is underlain by granitic rocks and there are at least three ages of these. The youngest rocks in the area are diabase dikes, which intrude all the previously mentioned formations.

Structure; The metasedimentary-metavolcanic belt of rocks represents the southern limb of a roughly east-northeast trending anticlinal structure which plunges gently west. The south side of the belt consists of metasediments and in this section the anticlinal limb is slightly overturned to the south. On the east side of the area, the belt is split into three branches which swing to the southeast. The southernmost branch consists of the sedimentary section of the belt which has been pried away from the metavolcanic section by a post-tectonic hornblende-biotite granite intrusion. The two northern branches may be the result of similar intrusive activity splitting the volcanic unit but there is also the possibility that it represents the overturn of the anticlinal fold. Small scale faults in the area generally strike approximately N.15 0 E. or N.65 0 W. Two regional faults have been inferred, one trending generally in the N.65 0 W. direction and the other closer to N.50 0 W. Direct evidence of shearing in the fault linears is rare, but characteristically in the granites, the faults are marked by hematitic carbonate gouge-filled shears, associated with red albiti zation of the adjacent granite. Albitization may be complete near the fault and diminish outwards to red albite-lined fractures cutting the normal granite. - 22 -

Economic Geology: The most interesting feature in the area is a band of predominantly metarhyolite or acid tuff which extends from midway between Valley Lake and the Black River, on the west, east-northeastwards for about 6 miles to Highway 614, just south of Summers Lake, and then eastwards to the border of the area. The rocks in this band are characteristically muscovite gneisses and are frequently high in pyrite. The Kusin©s Pb-Zn showing outcrops in metavolcanic hornblende gneiss just north of this metarhyolite band. Silicified, pyritic, northeast-trending zones occur in the hornblende gneiss and in one of these sphalerite and galena occur with the pyrite. Grab sample analyses showed 1.93^ Zn, 0.94^ Pb and 0.64 oz/ton Ag. A major fault trending N.65 0 W. is believed to exist about 1,000 feet southwest of the showing. The VonKlein Cu-Ni occurrence is located on the east border of the map-area. There are several sulphide showings and, in what appear to be the two richest zones, the chalcopyrite-pyrrhotite-pyrite mineralization seems to be confined to two separate, large blocks of amphibolite; one apparently is rafted in a rhyolitic breccia plug and the other is in a rhyolite or acid welded tuff. Mineral ization in the surrounding muscovite-biotite gneisses is minor. Some of the other showings carrying Cu and Ni values occur in shear zones in the pillow lavas and garnetiferous agglomerate north of the acid unit. A geological map of a 52-claim block was prepared by Mcintyre Porcupine Mines Ltd. in 1962 and some of the known showings were drilled. In 1963 Mining Corporation of Canada Ltd. did a small amount of drilling in the same muscovitic gneiss band just east of the Black River.

No. 10 DAYOHESSARAH LAKE AREA

DISTRICT OF ALGOMA

by

K. G. Fenwick

Location: The area mapped during the 1964 field season includes Common, Tedder, Hunt, 66, and Cooper townships; the southern halves of Johns, Odlum and Strickland townships; and the east half of Welsh and the west half of Matthews townships. In the southwest corner of the map-area is the town of White River. Hunt township is accessible by Highway No. 17. Welsh and Matthews are accessible by car from Regan along the Abitibi Power and Paper Company roads. Approximately 400 square miles were mapped.

Department of Geology, Queen©s University, Kingston, Ontario. - 23 -

Mineral Exploration: There was little activity in this area until 1957- In 1957 and 1958, the Canadian Pacific Railway Company did a reconnaissance survey of the Dayohessarah Lake volcanic-sedimentary belt, the Kwinkwaga Lake areawhich is at the western side of the map-area, and also the Kabinakagami Lake area which includes the eastern side of the area.

In 1964, Falconbridge Nickel Mines Ltd. staked 230 new claims in the townships of Drew and Cholette which are directly north of the author©s map-area.

In the near future, the Ontario Department of Highways will be putting a road approximately through the centre of the map-area, joining Highway NO.17 to Hornepayne.

Recently, the Ontario Department of Mines published aeromagnetic maps of this region and the Ontario Department of Lands and Forests rephotographed it.

General Geology: All the bedrock in the map-area is of Precambrian age. Dayohessarah Lake is underlain by metavolcanics and metasediments that form a narrow belt, which is between l and 3sf miles wide and approximately 24 miles long. The centre of this belt was mapped during the 1963 field season and the north and south extension of it was mapped in 1964* The belt surrounds Dayohessarah Lake and was traced northward to a point just north of Strickland River in Bayfield township and southward to the northwest corner of Cooper township. The east boundary passes through the west shore of Gagegenha Lake and the west boundary is 2 mile west of Dayohessarah Lake. The metasediments, which includes quartz-plagioclase-biotite schists and gneisses, garnetiferous biotite schists and a narrow band of conglomerate, occupies the central section of the belt. The metavolcanics, which are predominantly flows on the east and tuffs and flows on the west, enclose the metasediments. Inclusions of amphibolite are found in the granite rocks throughout the area.

The metavolcanics and metasediments are intruded by sills, dikes and small stocks of granitic material, and a migmatite complex is found along the west shore of Dayohessarah Lake.

Granite gneiss, pegmatite and massive pink granite are the principal igneous rocks outside the boundaries of the Dayohessarah Lake metavolcanic-metasedimentary belt. Pegmatites are very prominent in the south part of the map-area and are seen as high ridges and cliffs. - 24 -

The youngest rocks are diabase dikes which intrude all other rock units.

Structural Geology; The major rock units of the belt trend north westerly through the south and central portion of the area, and swing to trend northeasterly in the area north of Plate and Hambleton lakes. The schistosity in the metavolcanics and the banding and schistosity in the metasediments are very pronounced and follow these trends. The gneissosity of the granite gneiss also follows these trends. No major faulting was recognized, although a number of prominent topographic linears, recognizable in air photographs, occurs through out the map-area.

The diabase dikes, throughout the whole region, strike either northwest or northeast. Economic Geology: Unmineralized quartz veins are common in the metavolcanics. Pyrite and magnetite are disseminated throughout the metavolcanics and in the diabase and basic intrusive dikes.

There are large sand and gravel deposits in the area.

Minor sulphide mineralization is found in the map-area in the metavolcanics and granites.

No. 11 TOWNSHIPS 2? and 28, RANGE XIII DISTRICT OF ALGOMA

by P. E. Giblin1

Location: Townships 27 and 28, Range XIII, are located in the District of Algoma, near the east shore of Lake Superior, about 40 miles north of Sault Ste. Marie. Mineral Exploration; In 1955 Sylvanite Gold Mines, Limited, carried out diamond-drilling upon a copper prospect located in Township 28, Range XIII.

Resident Geologist, Ontario Department of Mines, 1496 Wellington Street East, Sault Ste. Marie, Ontario. - 25 -

Tribag Mining Company, Limited, acquired the above-noted prospect in 1961, and has since conducted exploration work almost continuously. To date, approximately 100,000 feet of diamond- drilling have been completed. Early in 1964 a 3-compartment shaft was sunk to a depth of 788 feet, and level stations were established at depths of 369 feet, 621 feet, and 747 feet. Cross-cutting is in progress on the deepest level, and diamond-drilling is being carried out from this level.

During 1963 and 1964 Quonto Explorations, Limited, drilled 11 holes, having a total depth of 7,770 feet, upon a property in Township 28, Range XIII. General Geology; Township 27, and the southern one-third of Township 28, Range XIII, are underlain by Archean basic metavolcanic rocks, with minor amounts of banded iron formation and acid metavolcanic rocks.. The northern two-thirds of Township 28, Range XIII, is underlain by granite, which has intruded the metavolcanic rocks. Diabase dikes, of probable Keweenawan age, intrude the metavolcanic rocks and the granite.

In the southeast quarter of Township 28, Range XIII, several large breccia zones occur on the property of Tribag Mining Company, Limited. The breccia zones are younger than the diabase dikes.

A basic dike cross-cuts one of the breccia zones, and is, apparently, the youngest intrusive rock in the area. Pleistocene deposits consist of till, gravel, sand, and varved clay. Economic Geology: Known copper mineralization of economic interest is confined to the breccia zones. The breccia zones are found close to the contact of the granite and the metavolcanic rocks. The principal copper-bearing breccia zone, which is currently being explored underground, is known as the Breton zone, and occurs in granite, a few hundred feet north of the granite-metavolcanic contact. The other known breccia zones occur in metavolcanic rocks. Of the 5 known breccia zones, one is a fault breccia. The others, including the Breton breccia zone, have many of the attributes of diatreme deposits, and are possibly genetically associated with Keweenawan volcanism. The Breton breccia consists of sharply-angular fragments of granite, diabase, and metavolcanic rocks, cemented by a coarsely- crystalline, vuggy, matrix of quartz, carbonate, and minor fluorite.

Chalcopyrite and pyrite, accompanied by minor amounts of galena, - 26 -

sphalerite, and molybdenite, are found in both the matrix and the fragments of the breccia, but occur predominantly in the matrix. Neither the shape nor extent of the Breton zone has yet been well defined. From present data, the zone appears to be a pipe- like body, with steeply-dipping walls. At surface the zone is at least 700 feet long by 400 feet wide. Drilling results suggest that the zone becomes both longer and wider with depth; and that the breccia extends to a depth of at least 1,345 feet. Although minor chalcopyrite is found almost everywhere through out the Breton breccia zone, the principal concentrations of chal copyrite appear, from drilling information, to occur as gently- dipping, to flat-lying, bodies. Based on results of surface drilling, the company recently estimated that there are 2,462,500 tons averaging 1.57 percent copper present in 5 zones; with l of these zones containing 1,025,000 tons grading 2.31 percent copper.

No. 12 TOWNSHIPS OF PROCTOR AND LEWIS AND PARTS OF SERPENT RIVER

INDIAN RESERVE (l.R.7), DISTRICT OF ALGOMA by J. A. Robertson

Introduction; The area lies north of the North Channel of Lake Huron. The Trans-Canada Highway (No. 17) and the Canadian Pacific Railway (Sault Branch) cross the southern part. Highway No. 108 runs close to the west margin. The Serpent River and connecting streams and lakes form the drainage and provide access. The northeastern part of Proctor township is accessible by private road from Nordic mine. Mineral Exploration; Prospecting for copper and other base metals has yielded no significant discoveries. During the Blind River uranium boom much of the area was staked and explored, particularly in southern Lewis township. These explorations proved fruitless. Lean magnetite iron formation with disseminated pyrite occurs near Highway No. 108 in the northwestern part of Proctor township.

l Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 27 -

Seven claims are held by M. Keba of Elliot Lake but no extensive development has been carried out.

Small sand and gravel pits have been opened to service Highways Nos. 17 and 108. Sand and gravel along the Serpent River is relatively inaccessible.

General Geology: The Murray Fault lies in a valley near the south boundary of Lewis township. The rocks found north of the Murray Fault fall into three main units:-

(1) The Archean basement comprising Keewatin(?) volcanic and sedimentary rocks and Algoman granites. Keewatin basic lavas, greywacke, and quartzite, with minor pyroclastics, conglom erates, and iron formation outcrop in the northern part of Proctor township. These strike northwest with moderate dip but to the eastward swing to an easterly strike with steep north dip. Iron formation provides a useful stratigraphic marker. The granites are grey to pink, massive to gneissic, and may have much partially assimilated Keewatin(?) material. Massive red quartz monzonite may be a late phase. Aplite and pegmatite dikelets and segregations are slightly radio active. (2) Huronian Rocks: Slightly metamorphosed feldspathic quartzite, argillaceous quartzite, and argillite representing the Lower, Middle and Upper Mississagi formations, outcrop on the north side of the Murray Fault. These are vertical with tops south and lie unconformably on the Archean. Slightly radioactive quartz-pebble conglomerates have been noted in the Lower Mississagi near the Lewis-Shedden township boundary. (3) Numerous diabase dikes (striking northwest and west-northwest) cut the Archean and are probably equivalent to the Post- Huronian (Nipissing) diabase. The area south of the Murray Fault is underlain by meta-quartzite, graded staurolite-mica schist (tops generally south), and diabase intrusions. The early workers believed these to be Archean but they are probably metamorphosed Middle Mississagi quartzites and argillites and Nipissing diabase. Much of I.R.7 is underlain by the massive to gneissic, grey to pink Cutler granite, post-Huronian in age (1,750 million years). Coarse simple pegmatite is common. - 28 -

Inclusions of the metasediments and of epidiorite or horn blende schist representing the Nipissing diabase are frequent. Structural Geology; The major structural feature is the Murray Fault which separates the undoubted Huronian and the Cutler granite- metamorphic rock complex. The fault strikes north-northeast with near vertical dip.

The Depot-McCarthy lakes system may lie along a fault zone. The area straddles the eastward continuation of the Chiblow Anticline. The stresses developed during the folding probably account for the numerous fractures filled with diabase and for the post-diabase fractures. An extensive northwest-striking quartz vein south of McCarthy Lake appears to be later than the diabase. Drift is restricted to the areas between outcrops. Glaciation was from about N. 15 0 E. Economic Geology: With the exception of the iron formation no extensive sulphide mineralization was found in the belt of Keewatin(?) rocks. Minor disseminated sulphides including pyrite, pyrrhotite, and chalcopyrite was noted in most Keewatin rocks. Minor chalcopyrite is characteristic of the diabase dikes. Chalcopyrite has been noted in a quartz vein southeast of Hope Lake and also in a quartz vein at the southeast end of Lillie Lake. Barren quartz veins occur in Proctor township and a large northwest-striking vein has been mapped southwest of McCarthy Lake.

The greenstone belt and the Murray Fault zone would normally be considered favourable prospecting areas but during mapping little encouragement was received for this point of view.

No. 13 WATERS TOWNSHIP

DISTRICT OF SUDBURY

by K. D. Card

The map-area extends from 4 to 10 miles southwest of the city of Sudbury, and includes Lively townsite. The Creighton mine (l.N. Co.) is located about a half mile north of the northwest corner of Waters township.

Resident Geologist, Ontario Department of Mines, Box 1030, Sudbury, Ontario. - 29 -

General Geology: The rock units from the oldest to the youngest are as follows:- Metavolcanic Group: mainly mafic metavolcanics and a large rhyolite body, the Copper Cliff rhyolite, with lesser amounts of metasedimen- tary (tuffaceous?) material. Sparse sulphide mineralization occurs throughout the metavolcanics. Creighton Granite: a composite granitic body composed of pink and grey porphyritic and equigranular "granites" of similar ages. Metavolcanic and metasedimentary inclusions are abundant. The granite is extensively brecciated, especially along the north boundary of the township. Metasediments: pelitic metasediments, polymictic conglomerate (Ramsay Lake) and quartzite (Wanapitei) occur in the southern two-thirds of the township. They are in normal stratigraphic order and for the most part are separated from the metavolcanics by faults. Metagabbro: hornblende metagabbro and amphibolite bodies intrude the foregoing rocks. Minor remnants of the unaltered pyroxene gabbro occur in some intrusions. Copper Cliff Offset: this offset dike of the nickel irruptive occurs in the northeast corner of the township. Variable amounts of sulphides occur throughout the dike. Trap and Diabase: dikes of trap and diabase intrude all other rocks. Structural Geology: A major regional fault (Worthington-Murray) strikes easterly through the township. The probable direction of movement on the fault was south side up and west with respect to the north side. Other east-trending structures recognized are the Haughton and Makada faults. North- and northeast-trending faults are also present. The metasedimentary rocks are folded into a series of upright, southwest plunging anticlines and synclines. Several foliations and lineations are present. Shears and quartz veins are numerous. Breccias are developed in all the rock units except the late diabase and trap dikes. There are mainly crush-breccias consisting of frag ments of the country rock in a crush matrix. Shatter cones are common in the more argillaceous parts of the quartzite formation. Economic Geology; Minor sulphide mineralization, containing variable amounts of copper and nickel, occurs in "rusty schist" zones in the metavolcanics group. The Copper Cliff Offset contains pods and disseminations of copper-nickel sulphides. - 30 -

No. 13 LEINSTER, TYRONE AND KITCHENER TOWNSHIPS

DISTRICT OF SUDBURY by

K. D. Card1

Location; Leinster, Tyrone and Kitchener townships are located about 28 miles north of Sudbury. They lie 8 to 18 miles north and north east of the nickel mines on the north range of the Sudbury camp. These townships were mapped in reconnaissance fashion during July and August and part of September, 1964.

Mineral Exploration: Some mineral exploration has been done in Tyrone and Kitchener townships. The possible extension of the Foy offset, an offset dike of the Sudbury nickel irruptive was explored by Falconbridge Nickel Mines Ltd. and the International Nickel Co. of Canada Ltd. in Tyrone township in the 1950 f s. Minor sulphide mineralization was discovered. In Kitchener town ship, a sulphide occurrence at what is known as the Copenhagen shaft was investigated prior to 1932. Lenses of banded iron formation in the north-eastern part of Kitchener township have been tested by pitting.

General Geology: Precambrian metavolcanics, metasediments, and granitic, gabbroic, and diabase intrusions underlie the area.

The metavolcanics and metasediments, which occur as remnants in the predominantly granitic terrain, are amphibolite, amphibolitic gneiss, psammo-pelitic rocks and conglomerate. Primary textures and structures were discernible only in Kitchener township.

Migmatites, intimate mixtures of the older metavolcanic-metasedi- mentary rocks and younger granitic rocks, occur as envelopes around the metavolcanic-metasediment remnants.

Several varieties of granitic rocks were distinguished, namely quartz-feldspar-hornblende (biotite) orthogneiss, porphyritic "granite", and pink equigranular "granite". There are at least two ages of granite present, older gneissic varieties and younger massive types. Younger, probably Huronian, conglomerate (Cobalt?) and quartzite (Lorrain?) occur in the southeast corner of Leinster township. These rocks are probably separated from the older metavolcanics and granites by faults or an unconformity.

Gabbroic dikes and sills intrude the older rocks and are in turn intruded by northwest-trending diabase dikes, the youngest rocks in l Resident Geologist, Ontario Department of Mines, Box 1030, Sudbury, Ontario. - 31 ~

the area. Structural Geology: Gneissosity trends in the gneisses indicate major fold structures. In several localities in Leinster township, there is distinct angular discordance between foliations in the metavolcanic inclusions and in the enclosing granitic rocks. This possibly indicates rotation of the inclusions. Several northwest-trending faults were mapped and others may occur along prominent topographic lineaments. Economic Geology; No mineralization was discovered during the mapping. The only known mineral prospects are the Copenhagen sulphide occurrence, the iron formation in Kitchener township, and the copper-nickel sulphides along the Foy offset extensions in Tyrone township.

No. 14 HALCROW AND DENYES TOWNSHIPS

DISTRICT OF SUDBURY by J. F. Donovan

Location: The map-area comprises Halcrow and Denyes townships. The centre of the area lies approximately 120 miles northwest of Sudbury.

Mineral Exploration: Extensive exploration work was carried out in 1931-1932 at the time of the discovery of the Kenty gold mine in Swayze township, to the east of the map-area. The exploration was mostly concentrated in areas containing quartz veins and porphyritic acid volcanic rocks. Very little exploration has been done in the area in recent years. General Geology; All the bedrock of the area is of Precambrian age. The area has extensive glacial cover, notably in the southern part of Halcrow and Denyes townships, and the northern part of Denyes township. The oldest rocks of the map-area are acid volcanic rocks which occur as a wide band in the northern part of Denyes township and as small, discontinuous bands in Halcrow township. Younger intermediate

^Geologist, Ontario Department of Mines, Box 1030, Sudbury, Ontario. - 32 - to basic volcanic rocks occupy the southern half of Denyes township and most of Halcrow township. Closely associated in space and time with these volcanic rocks are bands of sedimentary rocks, predominantly conglomerate, greywacke, and quartzite. Intrusive granite is common in the northwest corner and along the western margin of Halcrow township. It ranges from fine- to medium-grained, and from massive to gneissic. The granite has affected the surrounding rocks with the development of a contact metamorphic aureole. Diabase dikes are the youngest Precambrian rocks in the area. Structural Geology; The major rock units strike east-west and are folded about an east-west trending fold axis. A synclinal axis crosses the central part of the map-area. The syncline appears to be doubly plunging; in Denyes township it plunges to the west, and in the western part of Halcrow township it plunges east. The north limb of the syncline is overturned, and the structure is cut off by the granite intrusion in the northwest part of Halcrow township. Few faults zones were observed in the area. The main one is found in Halcrow township and strikes northwest. The faulted areas are associated with zones of shearing and brecciation. Commonly Quartz veins but rarely calcite veins occupy shear zones. Economic Geology: The main economic interest has been in and around areas of quartz veins and porphyritic acid volcanic rocks. Quartz veins are prominent and the gold associated with these veins was intensively prospected in the 1930 f s. Unmineralized quartz veins are common in the basic volcanic rocks, notably if these rocks are highly sheared, fractured or near the granite contact. Disseminated pyrite is common in both the acid and intermediate to basic volcanic rocks. - 33 -

No. 15 MURPHY TOWNSHIP

DISTRICT OF COCHRANE by S. A. Ferguson

Location; Murphy township is in the Porcupine area about 5 miles by road northeast of Timmins. Tisdale township contains the central group of raines of the Porcupine area which produce gold, silver and copper, and Murphy township adjoins Tisdale township on the north.

Mineral Exploration; Due to the recent discovery of a major sulphide orebody containing zinc, copper and silver in the adjacent township of Kidd, exploration for mineral deposits was in progress during 1964* The mineral rights to all the land within the township are held either by the owners as patented lots or by staking, but to date no bedrock deposits of economic grade have been located.

Broulan Porcupine Mines, Limited investigated their claim groups by a magnetic survey and by drilling two holes in 1944- At about the same time a hole was put down in an adjacent claim in the southeast quarter of the south half of lot 6, concession I. Coniaurum Mines, Limited drilled a hole on the boundary of lots 2 and 3 j concession I during 1953- Two short holes were drilled by P. J. O©Neill in the southwest quarter of the south half of lot 7 1 concession III in 1956. During the summer of 1964 geophysical surveys were carried out in the south half of lots 2 and 3, concession V and on the north Kalf of lot 4) concession VI as well as on properties held by Ned Bragagnolo, Bruce-Presto Mines, Limited, Crackingstone Mines, Limited, Gulf Lead Mines, Limited and Texas Gulf Sulphur Company Incorporated. These surveys were followed by drilling on the Bragagnolo, Bruce-Presto and Texas Gulf Sulphur properties.

General Geology; The three main stratigraphic units are a sequence of older basic lavas overlain by a unit of acid to intermediate volcanic rocks which are overlain in turn by sedimentary rocks. The basic lavas are metabasalts consisting of uniform lava with associated zones of pillow lava and flow top breccia. The acidic to intermediate unit is believed to have been formed largely from fragmental materials and trachytic breccia is a common rock type associated with fine-grained trachyte. In lot 4, concession VI some adjacent outcrops consist of pale grey pillowed "trachyte".

Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 34 -

The outcrops of sedimentary rocks consist largely of feldspathic greywacke with fine flakes of biotite, and in a few places biotite is abundant. Lithic fragments are present in some narrow beds. Softer rock types, such as thin-bedded argillite, do not outcrop but have been intersected by drilling. In lot 11, concession II outcrops of conglomerate contain greenstone pebbles and associated pebbles of porphyritic (feldspar) trachyte which is similar to the pebble assemblage observed in Timiskaming conglomerates.

Intrusive rocks are represented by a few outcrops of serpentinized ultrabasic rocks and similar rock types are presumed to underlie the more strongly magnetic area in the southwestern part of the township. One dike of diabase was observed and diabase has been reported in one diamond-drillhole. Structural Geology; Generally the dips are steep and over much of the area the trend is in a northeasterly direction. However, to the east of Bigwater Lake the strikes in the acid volcanic rocks are in a southeasterly direction. A major sedimentary belt is present in the southwestern part of the township and another major belt of sedimentary rocks occurs in the northeastern part of the township. These sedimentary belts are presumed to occupy synclinal areas. Ground magnetic traverses were made in the strongly anomalous areas indicated on the aeromagnetic map (G.S.C. Map No. 298G- Pamour) in order to obtain additional detail on the shape and location of the associated geological bodies. The major magnetic anomaly in the western part of concessions II and III tapers at the western end but has a blunt eastern end. The eastern end of the anomaly terminates just west of a small outcrop of fine-grained trachyte. A fault trending at N.35 0 W. is assumed to be present between the strongly anomalous area and the trachyte. This assumed fault may branch from the Burrows-Benedict fault which trends N.15 0 W. in the northern part of Tisdale township. No evidence of the northward extension of the Burrows-Benedict fault has been observed. Economic Geology; A sulphide showing located on the southeast quarter of the south half of lot 71 concession III was formerly held by P.J. O©Neill but is now held by Ned Bragagnolo. The rock consists of a fine-grained trachytic breccia with some pyrite and pyrrhotite in the matrix of the fragments. In July, 1956 two holes with a combined length of 90 feet were drilled in the mineralized breccia. Five assays of material taken from these drillhhles showed that no gold or silver was present but three of the samples gave a nickel content from 0.13 to 0.18 percent. - 35 -

Drilling during the present summer has been planned to intersect zones of electrical conductivity located by geophysical methods within the acidic volcanic or sedimentary rocks. No reports of the location of significant amounts of sulphides have been released for drilling within the township.

Known Production of Sand and Gravel:

The following data has been submitted by the companies: Total Years Company Yards Yards

1951-1963 Broulan Reef Mines Ltd. 966,865 1953-1959 Hallnor Mines Limited 293,300 1,260,165

No. 16 OGDEN, DELORO AND SHAW TOWNSHIPS

DISTRICT OF COCHRANE

by H. D. Carlson1

Location: The area lies between longitudes 8l 0 05 f and 8l 0 28 f and latitudes 48 0 22 f and 48*27©, and is located immediately south of the towns of Timmins and South Porcupine in Ontario©s most productive gold-mining district. The most recent map of and report on these three townships were published respectively 30 and 40 years ago. During the 1964 field season re-mapping of Ogden township and the northern one-quarter of Deloro township was completed. Mineral Exploration; These three townships have been the scene of extensive and intensive mineral exploration efforts by many companies and individuals for more than fifty years, ever since gold was discovered in the Porcupine district in the first decade of this century. At present there is one producing gold mine in the area, the Aunor mine in northern Deloro township. Underground exploration and development is currently proceeding at two properties of Kenilworth Mines Ltd. in Ogden township. Past producers of gold include the Buffalo Ankerite mine and the Delnite mine, both in

-^Resident Geologist, Ontario Department of Mines, 155 Pine St., S., Timmins, Ontario. - 36 - northern Deloro township. Several other gold properties have been investigated in the past by underground exploration and development efforts. Asbestos has been produced in past years from two properties in Deloro and Shaw townships. A deposit of magnesite is currently under investigation in the southern part of Deloro township. More than half of the area of the three townships is covered by patented mining claims. Interest is developing in the possibility of discovering base metal mineralization here because of the relative proximity of the area to the known copper and copper-zinc orebodies in nearby Tisdale, Robb and Kidd townships. General Geology: The bedrock is all of Precambrian age; much of it, particularly in the southern parts of the townships, is covered by Pleistocene boulder-clay tills and glaciofluvial outwash deposits of sand and gravel. The oldest rocks are vol canics ranging from basalt to rhyolite in composition and including minor amounts of pyroclastic material; conformably intercalated with the volcanic rocks are sedimentary sequences, including cherty iron formation, greywacke, siltstone and slate. These older formations have been intruded by small stocks,bosses, sills and dikes of igneous rocks ranging in composition from serpentinite to sialic porphyry. These igneous intrusions are not all of the same age; the youngest are northeast-trending olivine diabase dikes. Structural Geology: The most important structural feature is the Porcupine-Destor fault which crosses the area from the northeast corner of Deloro township to about the midpoint of the western side of Ogden township. North of this fault in Deloro the structure and stratigraphy of the volcanic sequences has been determined in considerable detail and correlated with similar sequences in ad joining Tisdale township as a result of much detailed surface and underground mapping and exploratory drilling by mining and explor ation companies. South of the fault this kind of detailed work has not been done and the structure and stratigraphy of the volcanic assemblages are not well known. It is hoped that the present project will result in improved knowledge of the same.

Economic Geology: Gold - Past and present dividend-paying gold mines are all located north of the Porcupine-Destor fault. The ore zones consist of quartz-carbonate veins and lodes in lenticular, carbonatized mafic lava flows commonly in the vicinity of small, intrusive stocks of sialic porphyry. South of the fault there are a number of gold occurrences in generally similar geologic settings, though to date there has not been any profitable production . - 37 -

Magnesite - In the south-central part of Deloro township Canadian Magnesite Mines, Ltd. has a large deposit of magnesite apparently fromed as a result of hydrothermal alteration of an ultramafic stock, Metallurgical tests and marketing studies are currently underway to determine the feasibility of economic production from this property. Asbestos - A small amount of asbestos has been produced in past years from two properties in Deloro and Shaw townships. The chrysotile fibre occurs in small serpentinized ultramafic stocks or sills. Iron - The generally narrow, discontinuous bands of cherty iron formation, intercalated with the volcanic rocks in many places south of the Porcupine-Destor fault, may provide a possible future source of beneficiable iron ore. Base Metals - Minor amounts of chalcopyrite in association with more abundant pyrite and pyrrhotite have been reported from a number of places in the three townships. There are few outcrops in the southern half of the area, and little serious effort has been made here to explore for base-metal sulphide mineralization. The geology is favourable for such and the possibilities should not be over looked .

No. l? NIGHTHAWK LAKE AREA

DISTRICT OF COCHRANE

by E. J. Leahy1

Location; The Nighthawk Lake area comprises the townships of Cody, Macklem, Carman and Thomas. The centre of the area is approximately 18 miles due east of Timmins. Access to most of the area is by water A prolonged rainy season hindered systematic traversing of the area, and it is anticipated that most of the 1965 field season will be required to complete the mapping. With the exception of the north side of East Peninsula and several small islands on the west side of the township, the mapping of Macklem township is essentially completed; extensive traversing failed to reveal any outcrop in Macklem township east of the shoreline of Nighthawk Lake except for previously known outcrops along the south township line. In Thomas township, mapping is completed east of McCleod Creek as well as the northeast part of the township. In Cody township, the north ©concession 1 and part of the southwest corner are done.

Temporary staff geologist, Ontario Department of Mines, c/o Resident Geologist, 1496 Wellington St., E., Sault Ste. Marie, Ontario. - 38 -

No start has been made on the mapping of Carman township. Because of numerous rocky shoals in the lake, persons interested in exploration in the area are advised to obtain the photo mosaic navigational map of Nighthawk Lake, published in the spring of 1964 by the Canadian Hydrographic Service, Department of Mines and Technical Surveys, Ottawa, (price: 50 cents).

Mineral Exploration: Gold was discovered in the area in 1907 just preceding the great Porcupine . Most of the area has been prospected since that time and many of the claims in the north half of Cody and Macklem townships have been brought to patent, with considerable drilling having been done. Gold has been produced from the Porcupine Peninsular mine and the Goldhawk Porcupine mine, both in Cody township. Extensive trenching is common in the area so far mapped; the former Aquarius property in Macklem township has underground development to the 525-foot level.

The Timmins staking rush of this past year has again resulted in extensive staking in the Nighthawk Lake area, but so far little new prospecting is being done. Two prospectors are carrying out work consisting of trenching and limited drilling on a sulphide showing in Cody township. Some seismic work was done in early summer in north Macklem township and an airborne geophysical survey was being done over Thomas township. M and M Porcupine Gold Mines Ltd. presently is undertaking a re-assessment program of the former Malga Porcupine Gold Mines property along the Carman-Shaw township line.

General and Structural Geology; The general geology of the area can be seen on O.D.M. Map 2046, the Timmins-Kirkland Lake sheet, published in 1964. Revisions to the geology as shown on that map, resulting from the present field work, are as follows:

(a) The area of granite outcrops in southeast Thomas township extends further to the west and north. (b) The main structural trend in the southwest part of Macklem township and continuing on into Thomas township, is southeasterly, and pillow tops indicate that this area may be complexly folded. (c) Much of the area around East Peninsula in Macklem township, formerly mapped as serpentinized rocks, is a talcose chlorite-carbonate rock, probably derived from basic lavas, although some serpentinized peridotites were noted. - 39 -

Economic Geology; The zone of strongly altered rocks striking north easterly through Cody and Macklem townships, and just south of Destor-Porcupine fault zone, has yielded the only gold produced in the area. Extensive overburden necessitates drilling for further exploration of this zone. The rock extending from southwest Macklem township into Thomas township in a southeasterly direction is also strongly altered and should be further explored. During the field season some gold was found at an old pit in carbonatized basic volcanic rocks along the Macklem-Thomas township line.

Pyrite, sphalerite and chalcopyrite mineralization are found in a showing now being prospected in Cody township.

No. 18 POWELL AND CAIRO TOWNSHIPS

MATACHEWAN AREA

DISTRICT OF TIMISKAMING

by

H. L. Lovell 1

Location; The map-area is about 35 miles southwest of Kirkland Lake. The town of is in the southwestern part of Cairo township.

Mineral Exploration; Pax International Mines Ltd., producer of molybdenum and copper, and two former gold producers, Young-Davidson Mines Ltd. and Matachewan Consolidated Mines Ltd., are in Powell township. Although work has been done on many showings during past years, none was done in the summer of 1964, other than staking and surveying claims.

General Geology; Every major division of the general stratigraphic column for northeastern Ontario is present in the two townships. From oldest to youngest the rock types are: several varieties of volcanic rocks, ranging from basalt to rhyolite and agglomerate to tuff (formerly known as "Keewatin" rocks); old, tightly folded conglomerate, greywacke, and arkose (Timiskaming); bosses of ultra mafic to mafic intrusive rocks (Haileyburian); stocks and apophyses of felsic intrusive rocks (Algoman); old mafic intrusive dikes

Temporary staff geologist, Ontario Department of Mines, c/o Resident Geologist, 4 Government Road, E., Kirkland Lake, Ontario. - 40 -

(Matachewan); young sedimentary rocks (Cobalt); and young mafic intrusive dikes (Nipissing).

The Timiskaming, Haileyburian, and Algoman rocks were extended during the present mapping into areas designated as Keewatin greenstone on pre-existing geological maps.

Structural Geology; An anticline of volcanic rocks that has an east-west axis separates the remnants of two tightly folded synclines of sedimentary rocks. i Major faults exist along Mistinikon Lake, the Montreal River, Narrow Lake, Whiskeyjack Creek, Browning Lake, and highway 66 east of Matachewan.

Economic Geology: Gold, silver, molybdenum, and copper are the only metals yet found to exist in economic amounts. These metals, along with smaller amounts of lead, zinc, scheelite, fluorite, and contact metasomatic concentrations of magnetite are associated with felsic intrusive rocks (mainly Algoman syenite). Asbestos is found in ultramafic intrusive rocks (Haileyburian serpentinite). Nickel and barite are present. Many of the gossans are caused by pyrite concentrations in the wallrock near diabase dikes. Most of the showings of economic minerals are in apophyses of syenite and nearby country rock along the major faults and their subsidiaries, and in faults in the syenite stock in Cairo township. Gold is distributed erratically in quartz veins cutting carbonatized rocks that are coloured green by chrome mica. Similar "green carbonate" rock contains gold in Midlothian township, 15 miles southwest of Matachewan, and at Kerr-Addison Gold Mines Ltd., 55 miles northeast of Matachewan.

No. 18 FLAVELLE, GROSS, BLAIN, WILLISON, DAVIDSON, AND SHARPE TOWNSHIPS

ENGLEHART RIVER AREA

DISTRICT OF TIMISKAMING by l H. L. Lovell

Location; The block of six townships straddles the Englehart River. The west boundary of the block is about 6 miles east of Matachewan,

Temporary staff geologist, Ontario Department of Mines, c/o Resident Geologist, 4 dovernment Road, E., Kirkland Lake, Ontario. - 41 -

the south boundary about 8 miles north of Elk Lake, and the north east corner about 10 miles southwest of Kirkland Lake. Mineral Exploration; The two northern concessions of Flavelle and Gross townships are in the belt of old volcanic, sedimentary, and intrusive rocks that extends intermittently from Matachewan to Kirkland Lake. Since the height of prospecting activity in the 1930 f s, little work has been done. Economically unfavourable granitic and "Cobalt" sedimentary rocks make up most of the remainder of the six townships.

General Geology: The rock types are similar to those of the Kirkland Lake area. From oldest to youngest they are: volcanic rocks (formerly called Keewatin), old sedimentary rocks (Timiskaming), old mafic intrusive rocks (Haileyburian), felsic intrusive rocks (Algoman), young mafic intrusive dikes (Matachewan), and young sedimentary rocks (Cobalt). The Timiskaming sedimentary rocks extend from Cairo township, in which Matachewan is situated, into northeastern Flavelle township in the vicinity of Middleton Lake. A body of medium-grained amphibolite (probably recrystallized volcanic rock) about one-half mile in diameter was found in the previously unmapped area of granitic rocks. The amphibolite is 2\ miles west along the hydro line from the bridge crossing the Englehart River on the Management road. Structural Geology; The Timiskaming conglomerate in northeastern Flavelle township is probably the northern limb of a syncline. The beds strike northeast and dip south, and are overlain by Cobalt sedimentary rocks and underlain by intrusive Algoman syenite. On the southeastern contact of the Timiskaming conglomerate, a major fault passes through Middleton Lake and the swamp to the southwest. Economic Geology: The gold-bearing quartz veins are in a major fault zone that trends approximately N.60 0 E. through northern Flavelle township. Most of the gold and silver is associated with the syenite stock, and is found in the syenite and in the country rock near its contact. The most prominent metallic minerals are blebs of fine- and medium-grained pyrite, chalcopyrite, and galena in white and smoky quartz. Associated non-metallic minerals are purple fluorite, black tourmaline, and pink and white calcite. - 42 -

No. 19 WILLET, ROADHOUSE, LAWSON TOWNSHIPS

ELK LAKE AREA

DISTRICT OF TIMISKAMING by

B. E. MacKean

Location; The Elk Lake mapping project, started in 1963 with the mapping of James, Mickle, and part of Chown townships, was completed in 1964 with the mapping of Willet, Roadhouse, and Lawson townships. The area extends from Elk Lake, 32 miles northwest of Cobalt, to Calcite Lake, approximately 6 miles east of Gowganda. Preliminary maps of James and Mickle townships have been published and prelimin ary maps of Willet and Lawson townships will be published during the winter of 1964-65.

Mineral Exploration: Prospecting has been directed to the diabase areas and their immediate vicinity because these places have been shown empirically to be the most favourable for silver occurrences. Most showings were found and prospected between 1908 and 1926.

There are presently no producing mines in the area. Only a small amount of prospecting was carried out during 1963 and 1964, although most of the diabase areas are presently staked.

During 1964, a showing of argentite was found at the south end of Martin Lake in Lawson township. Diamond drilling was done in Willet township by Accra Explorations Limited, and in James township at the old Beacon property by Solomino Gold Mines Limited. G. S. Welsh has set up a small mill at the former Otisse mine, Mickle township, with plans to continue operations in the spring of 1965-

General Geology; The bedrocks, Precambrian in age, consist of Keewatin metavolcanic and metasedimentary rocks intruded by Algoman granodiorite; these are overlain unconformably by flat-lying Cobalt Group sedimentary rocks. The Nipissing diabase intrudes all the above rocks either as a sill or dikes, the sill being approximately 1,200 feet thick. A narrow, olivine diabase dike with plagioclase phenocrysts cuts the Nipissing diabase in Roadhouse township and extends from Willet township northwesterly across Roadhouse township.

Structural Geology; The flat-lying Cobalt Group sedimentary rocks have been faulted but not folded except in some local areas in contact with the Nipissing diabase; however, the folding here is more in the form of slumping.

Geologist, Ontario Department of Mines, Parliament Buildings, Toronto, Ontario. - 43 -

Several major and numerous minor faults were found, but no relationship between ore mineralization control and faulting can be shown in these localities.

Economic Geology: Known silver mineralization in the area is generally found in calcite veins cutting the Nipissing diabase and, where present, aplite dikes. The control of the silver-bearing calcite veins is not known, nor is the criterion for distinguishing barren calcite veins from silver-bearing veins.

Chalcopyrite and bornite are of minor importance in calcite and specularite veins in Lawson and Willet townships. It is tentatively suggested by the writer that the chalcopyrite and bornite mineral ization is earlier than the silver mineralization. Spectrographic analysis of three chalcopyrite-bornite samples show traces of tin (Q.01% - Q.10%) in two of the samples and the presence of manganese in amounts slightly greater than trace in all the samples. Barite is widely found; the most important showing, from which some barite had been shipped, is located approximately 7*500 feet east and 4*500 feet south of the northeast corner of Lawson township Niccolite and smaltite were seen in a pit near the Devlin shaft in the southeast corner of James township and were also seen with native silver at the Silvermen mine in Smyth township, north of Elk Lake.

No. 20 NORTH HALF OF SOUTH LORRAIN TOWNSHIP DISTRICT OF TIMISKAMING by l W. H. Mcilwaine

Location; South Lorrain township is located roughly 20 miles southeast of Cobalt, and is easily accessible via Highway No. 56? The area mapped covers approximately 63 square miles and is bounded by latitudes 47 0 14©N. and 47 0 8 T N., and by longitudes 79 0 38©W. and 79 0 26©30"W.

Mineral Exploration; South Lorain township has been extensively

Temporary staff geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 44 -

staked, with the northern portion almost completely covered by surveyed claims. Most of the original staking was prior to the First World War. The area was very active at that time but activity died out with the war and has only recently been reactivated.

Activity was very limited during the 1964 field season. Canadian Keeley Mines Ltd. (formerly Keeley-Frontier) was engaged in underground exploration. They were also remilling the old tailings. Mining Corporation of Canada Ltd. had a small surface drilling programme. General Geology: The bedrock, all of which is Precambrian, consists of metavolcanics (commonly referred to as Keewatin) which are mostly andesitic in composition, and good pillows occur in several localities. A hornblende granite, in the northeast corner intrudes the volcanic assemblage. Unconformably overlying these rocks are Cobalt group sedimentary rocks. The youngest rock type is the Nipissing diabase, in sill-like form, with a few small dikes which may be associated with the sill. Cenozoic deposits include sand and gravel mainly, with small areas of varved clays. Structural Geology; No evidence for faults with large displacement was found, but there are numerous topographical lineations indicat ing small scale faulting. Evidence to support a major fault along the Montreal River is very sparse. The diabase is in local rolls producing arches and basins. The topography of the area, in many cases, helps determine the bottom and top of the sill. Economic Geology; The main economic metal of the area is native silver. Cobalt also occurs in ore grades. The cobalt is found as arsenides. The weathered product, cobalt bloom, is used as a favour able indicator for silver mineralization. Copper, mainly as chal copyrite may be associated with the silver. Known silver occurrences are found in the diabase or else close to the contact, and generally are close to the top of the sill. All surface showings have probably been exploited, but further investigations could be carried out in the search for buried silver deposits. - 45 -

No. 21 LAKE NIPISSING AREA

DISTRICTS OF NIPISSING, PARRY SOUND, AND SUDBURY by S. B. Lumbers

Location: During the 1964 field season, reconnaissance geological mapping was begun in the Lake Nipissing area, Districts of Sudbury, Nipissing, and Parry Sound. The area consists of three map sheets, each of which covers about 1,700 square miles as follows: (l) Tomiko sheet, bounded by latitudes 46 0 30© and 47 0 00 T , and longitudes 79 0 00© and 80 0 00©; (2) North Bay sheet, bounded by latitudes 46 0 00© and 46 0 30©j and longitudes 79 0 00© and 80 0 00©; (3) Sudbury sheet, bounded by latitudes 46 0 00 f and 46 0 30©, and longitudes 80 0 00 T and 8l 0 00 T . About 2/3 of the North Bay sheet was mapped during the field season, and a few selected studies were begun in the other two sheets.

Mineral Exploration: Deposits of iron, copper, nickel, pyrochlore, allanite, brucite, apatite, nepheline, garnet, corundum, feldspar, mica, kyanite, industrially useful rocks, and sand and gravel have been explored or utilized in the Lake Nipissing area. At present, production is confined to sand and gravel.

General Geology: The North Bay sheet is underlain by a variety of Precambrian rocks consisting mainly of migmatitic paragneiss, migmatitic amphibolite, granitic migmatite, granitic rocks, and minor paragneiss and amphibolite. All of these rocks have been intruded by mafic dikes and they have been subsequently metamorphosed during the Grenville orogeny to the upper part of the amphibolite facies. Irregular-shaped bodies and dikes of granite pegmatite, probably of more than one age, are present throughout the area. Late, unaltered, gabbro dikes and unaltered gabbro stocks with associated granite pegmatite locally intrude the metamorphosed rocks; late alkalic complexes intruded by lamprophyre, carbonate, and basalt dikes are present within the Lake Nipissing basin and near the town of Callander. Biotite from an alkalic intrusion in the Manitou Islands has an age of 560 million years (age determined by the Geological Survey of Canada).

Ordovician sedimentary rocks were found in fault contact with metamorphosed Precambrian rocks near the village of Nipissing, and on the Manitou Islands in Lake Nipissing where the sedimentary rocks overlie Precambrian gneisses and alkalic intrusive rocks. l Geologist, Department of Mines, Parliament Buildings, Toronto, Ontario. - 46 -

Nearly 1/3 of the North Bay sheet is underlain by at least two, incompletely mapped, granitic batholiths that have undergone much deformation and recrystallization, particularly around their margins. Within the Grenville province near Marten River (Tomiko sheet), a granitic body, which is petrographically similar to granitic bodies mapped in the North Bay sheet, has a whole rock Rb-Sr age possibly in excess of 2,400 million years.

A few age determinations by the Geological Survey of Canada on biotites from metamorphosed Precambrian paragneiss within the North Bay sheet suggest that a marked metamorphic event affected the area about 1,000 million years ago; biotites from similar paragneisses within the Tomiko sheet near the junction between the Grenville and Superior provinces show a variety of ages all in excess of 1,000 million years. It is therefore probable that the Grenville orogeny has overlapped part of the Superior province and that Archean and Proterozoic rocks have been incorporated into the Grenville province. The extent of this possible overlap is now being investigated by isotopic studies.

Structural Geology; Migmatites, amphibolite, and paragneiss within the North Bay sheet display complex flowage folding, particularly around the margins of granitic batholiths which appear to have acted as buttresses during the folding and metamorphism.

Within the North Bay sheet, the general regional strike of fold axes and gneissosity is north to northwest. Previous mapping and preliminary work by the author within the Sudbury and Tomiko sheets suggest that this regional north to northwest strike of structural units continues to predominate in the Grenville province to within a few miles of the Superior province. The two geological provinces are separated by a zone of deformation, the Grenville front zone, that contains a marked northeast structural trend almost at right angles to regional structural trends found elsewhere in the Grenville province to the south. The width of this Grenville front zone appears to be variable, and the zone has been displaced at numerous places along its strike by longitudinal and transverse faults. Structures within the Grenville front zone are complex, and they probably formed over a long period of time at various crustal levels.

In the immediate vicinity of the Lake Nipissing region (North Bay sheet) are numerous late fault zones that generally strike within 20 degrees of west. The fault zones, which are up to two feet wide and which are marked by brecciation of wallrocks and by much hemati- tization, cross all the rock types and structures found in the metamorphic gneisses, migmatites, and granitic batholiths. Lamprophyre, carbonate, and basalt dikes are associated with these - 47 -

faults, and the wallrock gneisses and migmatites commonly display wide zones of shattering and hematitization. An Ordovician outlier near the village of Nipissing may be bordered by one of these hematite-rich fault zones. Some of this late faulting and shattering appears to be associated at least in part with the intrusion of the late alkalic complexes.

Economic Geology: Iron concentrations in a few of the late fault zones have been examined by trenching and diamond drilling. The iron is in the form of fine-grained, hard hematite that contains disseminated quartz. Disseminated hematite and magnetite are found in some of the metamorphosed granitic bodies and in granitic migmatite. North of the town of Sturgeon Falls, some layers of folded, granitic migmatite contain up to 15 percent magnetite crystals. A few concentrations of magnetite were found in metagabbro dikes.

Copper and nickel mineralization is associated with late, unaltered gabbro exposed along the shores and in islands of the southern part of Lake Memesagamesing which is in the southwest corner of the North Bay sheet. Many of the copper-nickel concentrations in this body have been explored by trenches, pits, and diamond-drilling. During the field season, numerous specimens were collected from this body for laboratory examination.

Uranium-bearing pyrochlore is associated with alkalic complexes exposed in some islands in Lake Nipissing. Two of these deposits have undergone exploration work: (l) the Iron Island deposit, and (2) the Manitou Islands deposit (Beaucage Mines Ltd.). Small occurrences of pyrochlore were found on Burritt Island which is north of the Goose Islands in Lake Nipissing, and in Darling Island in Callander Bay. Completion of the mapping of Lake Nipissing may uncover additional occurrences. Granite pegmatites found in the North Bay region do not appear to be abnormally rich in radioactive minerals. Some allanite is present in a few pegmatites; testing of several pegmatites with the geiger counter failed to show abnormal radio activity. Biotite, iron oxide, and amphibole are the most common, accessory minerals in the pegmatites; some contain muscovite and garnet. Apatite and tourmaline is concentrated in a few pegmatites. A few pegmatites have been quarried for feldspar and mica.

Nepheline syenite forms three ring dikes in the vicinity of Callander Bay. Two of the dikes range in width from less than l foot to about 20 feet; one (of the ring dikes) has a maximum diameter of 600 feet whereas the other has a maximum diameter of 2,600 feet. A third dike is exposed only along the east shore of Callander Bay, but its dimensions are probably much larger than those of the other two dikes. Sodalite, hydronephelite, and iron oxides are present in the nepheline syenite bodies. - 48 -

Brucite-bearing marble patches surrounded by granitic gneiss are exposed between the Mattawa River and Lake Talon in Olrig township The brucite deposits have been explored by trenching and diamond- drilling. Hematitization is associated with marble-granite contacts; botryoidal hematite masses and veinlets are present in the marble. Kyanite-bearing, quartzo-feldspathic gneiss which is inter- layered with amphibolite, migmatitic amphibolite, and rare ortho quartzite, is exposed over a large area in Phelps and western Olrig townships. Green kyanite is disseminated throughout the quartzo- feldspathic gneiss and crystals up to three inches long are concen trated in layers commonly less than two inches wide. In places the kyanite crystals constitute about twenty percent of the rock. Kyanite-bearing gneisses also occur in townships adjacent to Phelps and Olrig townships.

Ordovician carbonate sedimentary rocks in the Manitou Islands were quarried for use in the construction of the Canadian Pacific Railways© North Bay-Sault Ste. Marie line. Extensive deposits of sand and gravel throughout the eastern half of the North Bay sheet are used for local construction projects, for concrete, and for various precast concrete products.

No. 22 MADOC TOWNSHIP

COUNTY OF HASTINGS

by D. F. Hewitt

Location: During part of the 1964 field season detailed geological mapping of portions of Madoc and northern Huntingdon townships, County of Hastings, was carried out. Mineral Exploration; Madoc is the centre of an important industrial mineral industry. More than 19 marble quarries are operated principally for the production of terrazzo chips. Ontario©s only talc mine produces on the outskirts of Madoc village. Exploration of marble deposits was carried out by three companies in 1964. Some interest was indicated in iron deposits near Malone village.

Senior Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 49 -

General Geology; The area lies on the Paleozoic-Precambrian contact and the southern portion is underlain by Black River limestone. There are several outliers of Paleozoic rock north of the main contact which runs through Moira Lake. The Precambrian rocks consist predominantly of marble, schist and argillite, and acid and basic volcanic rocks, intruded by granite and syenite. The Tudor metavolcanics occupy the northeastern and eastern parts of Madoc township. The northwest corner is occupied by the Gawley Creek syenite, a large stock similar in petrography and appearance to the Mount Moriah syenite in Grimsthorpe township. The west central part of the township is occupied by the Deloro granite batholith. This batholith is a significant feature of the geology of the Madoc area, as gold, iron and copper deposits are grouped about the margins of the batholith.

A small acid volcanic centre with rhyolite, associated prrite deposits and black slates,occurs at the Queensboro pyrite mine.

Structural Geology; The marble lies in a synclinal structure trending northwest to the west of Tudor volcanics. Faulting is common ±n the area. The fluorspar deposits are localized along two northwest-trending fault systems which are post-Paleozoic in age.

Economic Geology; A large production of marble comes from three companies operating about 19 quarries in the Madoc area. Canada Talc Industries operate the Henderson and Conley talc mines and also produce marble chips. Although many fluorspar deposits are known in the area none were in production in 1964. There are several magnetite and hematite iron deposits extending in an arc around the margins of the Deloro batholith from Malone to Madoc village. There are several small gold and copper prospects which were formerly mined. Eldorado is the site of the first gold mine opened in Ontario in 1866. Pyrite was formerly mined near Bannockburn, Eldorado and Queensborough. Rhyolite and granite were formerly quarried for roofing granules.

No. 22 PARRY SOUND - HUNTSVILLE MAP AREA

by D. F. Hewitt1

A limited amount of reconnaissance geological field work was carried out in June and September in the Parry Sound-Huntsville area

Senior Geologist, Department of Mines, Parliament Buildings, Toronto. - 50 -

in connection with a geological compilation map on the scale of l inch to 2 miles. This sheet covers an area of 1,900 square miles west of longitude 79 0 W. and between latitudes 45 0 and 45 0 30 f N.

The principal mineral production is industrial minerals, including building stone, clay products, sand and gravel. Some exploration work was done on a diatomite deposit near Huntsville. During 1964 a test shipment of bornite-chalcocite ore was made from the McGown mine near Parry Sound.

No. 23 PLEISTOCENE GEOLOGY OF THE THORNHILL AND BOLTON AREAS by P. F. Karrow1 THORNHILL AREA

Location; The area is between latitudes 43 0 45 f to 43 0 52 f 30 MN. and longitudes 79 0 22©30" to 79 0 30©W. and covers Sheet 30MA4d of the National Topographic Series. The southern part of area, included in North York township, has been reported on (Ont. Dept. Mines, Ann. Rept., Vol. LXIV, pt. 7, 1957) and was not remapped. Geology; This area fills in a gap between the Scarborough area on the east, mapped in I960 and 1961 (report in press) and the Bolton area(see p.51)- Mapping was at a scale of one inch to one half mile. Most of the area is a level to drumlinized till plain, modified in many places by a thin to moderate veneer of lake clays, deposited in ice-marginal lakes during retreat of the last ice sheet to the southeast into the Ontario basin. Under the surface till sheet, having a silty to sandy texture, are extensive deposits of fine sand which are exposed in the moraine area west of Richmond Hill and along valley sides in the central and southern parts of the area. Older till sheets are presumed to extend under the area but were rarely seen in exposures. Bedrock (Ordovician grey shale) has a relief of over 400 feet with several buried valleys crossing the area. Economic Geology; Large deposits of sand are being exploited east of Thornhill and west of Richmond Hill. Gravel is obtained from the latter locality as well as from a buried kame deposit east of Richmond Hill and just north of the area boundary.

Department of Civil Engineering, University of Waterloo, Waterloo, Ontario. BOLTON AREA

The following notes are by O.L. White, the author*s senior assistant, who was in charge of the field work in the Bolton area.

Location; The map-area is located to the northwest of Metropolitan Toronto and includes large areas of Peel and York counties as well as smaller areas in the southern portions of Simcoe and Dufferin counties (N.T.S. Map Sheet 30M/13).

Mapping Progress; Work commenced in 1962 with the compilation of wellrecords and the investigation of some valley exposures in the southern portion of the map-area. Mapping commenced in 1963 and a preliminary map of part of the area covered at that time was pub lished in 1964 (Pleistocene Geology of the Woodbridge Area, No. P. 236). The mapping continued in 19&4 and the whole area has now been covered.

General Geology;

Bedrock; The area is underlain by rocks of Ordovician and Silurian age which outcrop in the southeast along several river and creek valleys and in the west along the Niagara Escarpment.

Glacial Deposits; A remarkable section in the Woodbridge area, exposed as a result of recent construction activities of the Canadian National Railways, reveals four tills of Wisconsinan age, sediments, rich in organic fragments, and another till, probably of Illinoian age. The two youngest tills cover the greater portion of the southern part of the map-area. Two tills, recognized in the northern portion of the map sheet, are believed to be different from the tills in the southern part of the area.

Between the northern and southern portions of the map-area and, covering over half the area mapped, a high, east-west trending ridge rises several hundred feet above the ground surface to the south. This ridge consists essentially of water laid deposits of sand, gravel, and silt, capped in places by a thin veneer of till. Within these glaciofluvial sediments, numerous sand and gravel pit operations are located.

Economic Geology;

Sand &1 Gravel; Major operations are located at Caledon, Maple and along the valleys of the Humber and the East Humber rivers, north of Woodbridge. Another extensive operation is located at the south ern edge of the map-area, a few miles north of Brampton. Many other - 52 -

individual workings, both large and small, active and abandoned, are located within the area. Peat; Numerous small operations are located throughout the northern portion of the map-area, particularly in King and Albion townships and to a lesser extent, in Caledon township. Other potential deposits abound throughout the area.

Crushed Rock: A small quarry, in Amabel dolomite, opened up in recent years, is not active at present. It is located to the east of Caledon. Other older operations are located on the Escarpment west of Inglewood.

No. 24 PLEISTOCENE GEOLOGY OF THE LONDON - ST. THOMAS AND PORT STANLEY AREAS

by A. Dreimanis

Location: The area is bounded by latitudes 42 0 30 T to 43 0 00©N. and longitudes 8l 0 00 f to 8l 0 30©W., and covers map sheets 401/11 and 401/14 of the National Topographic Series, (scale 1:50,000). Mapping Progress; Surface mapping of the map-sheet 401/14 and the eastern half of the 401/11 areas has been completed. A preliminary map of the western half of the 401/14 sheet has already been issued, and a brief summary of the general geology of the entire 401/14 sheet was published in last year©s summary of field work. Construc tion of a bedrock surface map is in progress. General Geology: The heavy textured Port Stanley till, covered by lacustrine silt and sand of various thickness, predominates in the eastern portion of the 401/11 map-area. The next older, the sandy Catfish Creek till is exposed in the Kettle Creek valley southwest of St. Thomas and in the Catfish Creek valley between New Sarum and Sparta. Stagnant ice landscapes are less common in this area than in the 401/14, and they are associated mostly with the Sparta moraine Ancient shorelines of lakes Arkona, Whittlesey and Warren are well developed. Dunes predominate in the Jaffa area, and along the Warren

Department of Geology, University of Western Ontario, London, Ontario. - 53 -

beach at Union.

Economic Geology; Most gravel deposits of the 401/11 map-area are associated with the shorelines of lakes Arkona and Whittlesey, while sand predominates along the Lake Warren beaches. Some gravel deposits are associated also with the Sparta moraine and the Catfish Creek drift. The recent Catfish Creek has reworked the gravelly Catfish Creek drift and redeposited it as alluvial gravels northeast of Sparta.

No. 25 MARL, DIATOMITE AND PEAT MOSS IN ONTARIO by l G. R. Guillet

Deposits of marl and diatomite were examined during the field season. A review of peat moss resources was started.

Deposits of marl are common in small spring-fed lakes located in the limestone belts of southern Ontario; they are particularly common in the counties of Grey, Bruce, Peterborough, Hastings, and Renfrew. Deposits occur sparingly in . Marl lakes are easily recognized by the blue-green colour of their water. Marl is a fresh-water precipitate of calcium carbonate, more or less mixed with shells and the skeletal remains of various algae. It was formerly used extensively in the manufacture of Portland cement. Although there has been no production of marl in Ontario for 20 years, it is a potential source of lime for soil fertilization and road stabilization. Marl of high purity and brightness may be suitable for certain filler applications. Diatomite deposits in Ontario appear to be restricted to the Muskoka region. Beds of grey diatomite 1-2 feet thick are occasion ally found interlayered with peat in small lakes and marshes near Huntsville. Deposits of diatomaceous peat are less pure but more common in the Muskoka area. Deposits of diatomite are formed by the accumulation of the siliceous skeletons of certain alga forms called diatoms. The fine cellular structures of these minute skeletons make diatomite especially useful for water filtration purposes. Several attempts to produce diatomite in Ontario have not been successful because of the small size of the deposits and the difficulty in removing impurities.

Geologist, Ontario Department of Mines, Parliament Buildings, Toronto. - 54 -

Peat moss occurs extensively throughout Ontario. Used as a soil conditioner, the demand for peat to improve heavy clay soils for residential landscaping is increasing. Several peat-harvesting operations have been developed in Ontario in recent years. Examination of peat bogs will be continued in 1965.

PART B. REPORTS FROM RESIDENT GEOLOGIST©S OFFICES

RESIDENT GEOLOGIST©S OFFICE

PORT ARTHUR

by

E. G. Pye1

The field season of 1964 was spent largely in mapping the Lac des Iles area 65 miles north-northwest of the Lakehead cities of Port Arthur and Fort William. In addition, a display was arranged for the Canadian Lakehead Exhibition, time was spent in the invest igation and acquisition of new office facilities, and instruction in elementary mineralogy was given to Junior Forest Rangers based at the Department of Lands and Forests headquarters in Sibley Provincial Park. Examinations of mineral occurrences on two properties, as described below, also were made.

R. Barker

This property is along Glacier Creek, about 4 miles south of Barbara Lake, which in turn is 20 miles south-southeast of the town of Beardmore. Two copper deposits have been located.

One deposit is along the west contact of a 30-ft. wide diabase dike of Keweenawan age that cuts massive Archean granitic rocks. It is a strongly sheeted quartz vein, with books and ribbons of chloritized diabase and, in places, altered granite. It strikes N.15 0 E. for a known length of 250 feet, and dips steeply east. Because only the west wall is visible, widths may exceed the 2-5 feet exposed. Associated with, and occurring mainly in, the quartz are calcite, pyrite, and chalcopyrite. According to R. Barker, sampling has indicated a fairly uniform copper content of 2-3 percent

Resident Geologist, Ontario Department of Mines, 179 S. Algoma St., Port Arthur, Ontario. - 55 -

The disbribution of the sulphides is such that it is quite possible the vein would not serve as a conductor amenable to geophysical exploration.

The second deposit is about 3/4-mile northeast of, and parallels the first. It also occurs in a diabase dike and is exposed in trenches at intervals over a length of 800 feet. Again sulphides are associated with quartz-carbonate vein material along a zone of shearing and brecciation. In most exposures the grade is l percent copper or less. However, in one trench, about midway along the structure, a chip sample across 10 feet, according to R. Barker, was found on analysis to contain 10 percent copper. Much of this copper is present as the mineral bornite.

It is of interest to note that the two deposits occupy structures which branch northward from a major post-diabase fault zone, which is marked by Glacier Creek and along which copper mineralization was investigated in 1956, first by Frobisher Limited and later by MacLeod-Cockshutt Gold Mines Limited. It is generally acknowledged that copper in quartz veins is not particularly attractive from the point of view of exploration. Also quartz veins in granitic host rocks generally have not proved of much economic importance. However, it is significant that the copper deposit on the property of Tribag Mining Company Limited, about 40 miles north of Sault Ste. Marie, is associated with a granitic host rock and is a breccia cemented by chalcopyrite-bearing, quartz-carbonate vein material.^

P. E. Giblin, Summary of Field Work, 1963, Ontario Department of Mines, P.R. 1963-2, 1963, pp. 46-4?.

Further, the veins on the Barker claims are post-diabase. The diabase probably is Late Precambrian in age. This being the case, there can be no genetic relationship between the veins and the Archean granite; the latter, because it is a brittle, competent rock, thus may be a favourable rather than an unfavourable host rock.

John Moschuk

The Moschuk property is in the northeast quarter of township 71, about 3 miles northeast of Ozone Station at the upper end of Kama Bay, Lake Superior. It is along the west side of a diabase- capped mesa, and is underlain by flat-lying sedimentary rocks of the Sibley group of Keweenawan age. The mineral deposit is in pink - 56 - sandstone and is a fractured zone cemented by thin veinlets of quartz and calcite carrying small amounts of sphalerite and a little galena. This zone strikes northwest and dips vertically. It is exposed in a trench across a width of 5 feet.

A parallel quartz-calcite vein, about 12 inches wide, lies 60 feet southwest of the first. It also contains a little galena and is reported to contain some silver.

RESIDENT GEOLOGIST©S OFFICE

TIMMINS by H. D. Carlson ^

Chapleau - Foleyet Compilation Sheet t The work of compiling and assessing the available data for this map is nearly complete, and it is hoped that preliminary maps of most of the area covered can be made available to the public in the next few months. However final publication of the map will be delayed until the results of much recent and continuing exploration work in the general region to the northeast of Foleyet are made available to the Department by the companies concerned. Property Examinations; The discovery by the Texas Gulf Sulphur Company early in 1964 of a large copper-zinc-silver orebody in Kidd township, some 10 miles north of Timmins, touched off one of the largest property acquisition booms in the history of Canadian mining. Since that time more than one hundred companies have taken up ground in the region north, west and east of the original Porcupine gold camp. More than fifty companies have either completed initial drilling programs on their properties or are currently engaged in the same. The region being explored is almost entirely covered by a thick mantle of glaciofluvial clays, drift and sand and gravel outwash deposits. Outcrops are scarce and widely scattered. It is therefore imperative that data obtained from core-drilling be obtained and preserved. To this end the writer has visited 20 properties and logged the core from 80 holes, selecting suitable representative samples of the rock formations cut for comparative purposes and petrographic study. These efforts will continue during

Resident Geologist, Ontario Department of Mines, 155 Pine St. S., Timmins, Ontario. - 57 - the winter months and it is hoped that little valuable information will be permanently lost. Office Services: Considerable time was spent in consultation with exploration personnel who visited the Resident Geologist©s office in Timmins to examine maps, assessment work files and the various publications on hand.

RESIDENT GEOLOGIST©S OFFICE

COBALT by Robert Thomson

No area for systematic mapping was assigned to the Resident Geologist, Cobalt, for the 1964 field season. In carrying out the regular duties of resident geologist examination of numerous properties in the area was made. Notwithstanding the world wide shortage of silver and its rise in price prospecting for silver in the area as a whole appears to have been less than in previous years. The most interesting and important developments in the area appear to have been in the Cobalt camp. Two companies, Silverfields Mining Corporation Ltd. and Hiho Silver Mines Ltd. (a subsidiary of Glen Lake Silver Mines Ltd.) have found important silver deposits -- deposits typical of the most productive part of the camp. The Hiho deposit is the first important silver deposit ever to have been found in the township of Gillies Limit.

-^-Resident Geologist, Ontario Department of Mines, Box 799, Cobalt, Ontario. - 58 -

RESIDENT GEOLOGIST t S OFFICE

SAULT STE. MARIE by l P. E. Giblin

Most of the field season was spent in mapping Townships 27 and 28, Range XIII. Results of the work are described elsewhere in this report. A little time was devoted to routine duties of a resident geologist.

The principal prospecting and mining activities within the territory of the resident geologist stationed at Sault Ste. Marie were carried on in the Batchawana area, located about 40 miles north of Sault Ste. Marie.

Tribag Mining Company, Limited, completed shaft-sinking operations at the company©s copper prospect located in Township 28, Range XIII. Crosscutting and underground diamond-drilling are in progress . The geology of the deposit is described else where in this report.

International Mine Services, on behalf of several associated companies, conducted a program of geological, geochemical, and geophysical surveying in Ryan and Palmer townships. Diamond- drilling is currently in progress.

McKinney Gold Mines, Limited, is carrying out diamond-drilling upon a copper prospect in Ryan township.

Quonto Explorations, Limited, drilled 2 holes upon a property located in Township 28, Range XIII.

Resident Geologist, Ontario Department of Mines, 1496 Wellington Street, East, Sault Ste. Marie, Ontario.