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. 48006'30" MARGINAL NOTES Ministry of Hon. James A.C. Auld LOCATION AND ACCESS: The McFadden and Rattray Town cambrian (Archean) basement complex and extends northwards Minister ships area, situated along the Ontario- interprovincial boun from the Cobalt Embayment. The depression, referred to by the Natural dary line, is centered 14 km southeast of the town of author as the Larder Lake Trough, is interpreted as a fiord-like Dr. J. K. Reynolds Deputy Minister and includes areas delimited by Latitudes 470 55©30" to 480 06©00" rift valley bounded by a system of steeply inclined faults which Resources and Longitudes 790 31©00" to 790 38©00". Eastern portions of the underwent periodic displacements throughout the Middle Pre Ontario area are accessible via Highway 66 eastward from Kirkland Lake cambrian. Variations in the dips of Coleman -rocks reflect the and then south along the interprovincial boundary road. Road control of bedrock topography and the steepening effect of access to the southern sector of Rattray Township is possible supratenuous compaction during diagenesis of sedimentary rocks along secondary roads extending eastwards from the - on the flanks of the subsiding trough. Intraformational breccias, Larder Lake Highway 624. Western and central portions of the slump structures, ball and pillow structures, clastic dikes, fissure- Hines L area can be reached by motor boat on Larder Lake and by canoe filling quartz vein systems and local variations in dip near steep Beach and portage from downstream to Corset and Ward vertical offset faults are common in Coleman rocks and evidence Lakes and the Larder River. Numerous unmaintained trails and a history of sedimentation under conditions of periodic tectonic ONTARIO GEOLOGICAL SURVEY logging roads occur throughout the area. instability. ©-w , PRELIMINARY MAP P.2244 MINERAL EXPLORATION: Widespread prospecting stimulated ECONOMIC GEOLOGY: McFadden and Rattray Townships are l \ l GEOLOGICAL SERIES by discoveries of silver ores at Cobalt in 1903 eventually led to an situated immediately south of McGarry Township (geological important gold find near the northeast arm of Larder Lake in report by Thomson 1941) where the Kerr-Addison gold mine August 1906. This discovery became the major gold producing occurs hosted in favourable carbonatized rocks of the Larder x8b/© l Kerr-Addison mine at Chesterville in 1936; the site being situated Lake-Cadillac Fault. Lovell and Ploeger (1978), Ridler (1970) and f approximately 4.3 km north of McFadden Township. Unrecorded Savage (1964) have described various ore-types of gold mineral early prospecting in the area is evidenced by numerous pits, ization occurring in the Kirkland Lake-Larder Lake camp and AREA trenches and drill holes in abundant though erratically distributed have given guidelines for exploration. In the map-area, greatest DISTRICT OF TIMISKAMING pyritiferous quartz-vein systems. potential for exploitable concentrations of gold lies within Early Data on file at the Kirkland Lake Resident Geologist©s office Precambrian rocks which comprise a zone a few kilometers wide Scale 1:15840 record gold exploration in the area by Lucky Girl Mines Limited(1). occurring in the west-central parts of the map-area. Certain lith- ological and structural conditions within this arcuate fold belt Mile ^ Mile In 1947 this company put down four diamond drill holes (total l—p-l i—i h-l l—l l—I" length 464 m) at the south end of Island CC on Larder Lake (best fulfill some of the criteria which have been found to be amenable to gold mineralization; (1) carbonatized and syenitized rocks Metres 100 0.2 1 Kilometre assay 0.2 oz./ton Au/5©) and a number of holes on the south and e: "E^——l east shores of the lake. In 1948, P. Wojcieszyn (2) conducted fur with quartz stringer networks, (2) proximal syenitic intrusions ther exploratory diamond drilling for gold on Island CC (4 holes with slight sulphide mineralization (Wolfe 1976 discusses im portance of gold concentration in Precambrian felsic plutonic 930 m) and in 1951-1952 and 1968 E. Lipasti (3) diamond drilled NTS Reference: 32D/4E (17 holes, < 1000m) several sites on the east and west sides of Big rocks as indicator of mineralization), (3) subsidiary branch Pete Island in Larder Lake to test intrastratal volcanogenic faulting off the ore-concentrating Larder Lake Fault may have ODM-GSC Aeromagnetic Map: 47G localized the occurrence of ore. Milky Creek, Northeast Arm- sulphide mineral occurrences. Diamond drilling of five holes ODM Geological Compilation Map: 2205 (total length 460 m) performed by Kerr-Addison Mines Limited Benson Creek, and Southwest McFadden Faults (Thomson 1947) (4) in 1956 explored a showing of copper mineralization on the are all possible transecting faults of the Larder Lake-Cadillac west side of lcefish Lake in Rattray Township (best assay Q.26% Break, (4) narrow sulphide-bearing cherty-tuff horizons (inter OMNR-OGS 1979 Cu, Q.07% Ag). In 1976, Geophysical Engineering Limited (5) flow sedimentary rocks occur randomly distributed within the metavolcanic sequence and are known to be an important host Larder contracted airborne magnetometer and electromagnetometer Parts of this publication may be quoted if credit is given and the material rock for auriferous pyrite at the Kerr-Addison mine. surveys which included coverage of the northwest corner of is properly referenced. McFadden Township; and in 1977 Colex Explorations Incorpor Lithologic conditions in the vicinity of Island CC which Boundary ated conducted airborne magnetometer and electromagnetometer appears to be related to a volcanic conduit or hypabyssal dome surveys over west-central portions of the area and ground mag are appropriate for the occurrence of volcanogenic massive netometer, electromagnetic and soil geochemical surveys over sulphide mineralization. Small, (^ 2 m wide), steeply dipping zones Islands Big Pete and CC and adjacent lake areas. Although geo . of sulphide-bearing intrastratal cherty-tuff occur within the physical and geochemical anomalies have been detected and there 1 oV/7?. 1 8p,8b massive to pillow-form flows on Islands Big Pete and CC and are indications of gold, copper, and lead-zinc mineralization from within the metavolcanic complex to the south. There is also a drill cores; no economic mineral deposits or prospects have been possibility of economic gold or massive sulphide mineralization located. However, approximately 50 mineral exploration claims in Early Precambrian rocks which underlie the Coleman rocks of are held active in the area and the possibility of ore mineralization the Larder Lake Trough. The extensive and thick cover of Cole has not been ruled out for a large portion of the area. man rocks necessitates detailed deep-probing geophysical meth GENERAL GEOLOGY : The map-area lies at the boundary be ods to locate favourable shallow conductors for drill follow-up tween the south-central part of the Superior Province and the to obtain stratigraphic, structural and assay data on rocks under Cobalt Embayment of the Southern Province, some 130 km lying the Coleman member. north of the Grenville Front. Bedrock formations consist chiefly Numerous quartz veins of variable dimension and continuity of Early Precambrian (Archean) metavolcanics, metasediments, pervade the Coleman rocks and have been proven by early pro and plutonic rocks, and Middle Precambrian (Huronian) sedi specting to be barren of significant mineralization other than mentary rocks, belonging respectively to the Abitibi Belt and the pyrite near surface. However, given favourable geochemical Cobalt Plate (or Embayment) structural subprovinces which are gradients and auriferous source rocks nearby, it is possible that separated by a profound angular unconformity. Small isolated some of the more extensive fissure-filling veins have tapped occurrences of northeast-trending mafic intrusive rocks have been precious metal sources and are mineralized at depth. Coleman classified as Late Precambrian (Keeweenawan) diabase. Pleisto rocks display certain genetic affinities with the tillite-bearing •fcfzr 7 J 'w y cene deposits of lodgement and ablation till, sand and gravel, Witwatersrand succession in South Africa which hosts important W x varved lacustrine clays, and esker sand; together with Recent gold-uranium placer concentrations (Pretorius 1974). Basal deposits of muskeg and alluvium make up the surficial deposits Coleman conglomerates situated down transport direction from overlying the bedrock. Early Precambrian gold deposits and uraniferous granitic terrains LOCATION MAP Scale: 1: 1 584 000 or 1 inch to 25 miles of the Larder Lake Fault might be possible repositories of Rand- Early Precambrian rocks are of limited areal extent within the Y/ v type gold-uranium placer concentrations though the requisite Vtr area and occur mainly on the large islands in the south of Larder sorting and textural and compositional maturity are lacking in Lake Lake and along a narrow belt in low-lying largely drift covered most of the exposed Coleman section. tX ^ 0 areas to the south of the lake where carbonatized rocks were \x ^, ^ o frequently encountered. The metavolcanic sequence consists of Occurrence of pyrope garnets and chrome diopside in Pleis structurally complex, interlayered or successive, massive and tocene glacial tills of the Kirkland Lake-Larder Lake area in pillowed, mafic to ultramafic lava flows occasionally grading into dicates a derivation from kimberlite (Ferguson and Freeman coarser differentiated mafic to ultramafic rocks which are massive 1978). This alkaline intrusive rock type occasionally hosts dia LEGEND and often serpentine-bearing or pyroxenitic. Interbeds of derived monds and can also be the source of alluvial placer diamond proximal fine-grained to coarse-grained metasediments and mud concentrations. Small kimberlite dikes outcrop near Larder Lake PHANEROZOIC raising the possibility of diamantiferous occurrences within the flows display complex spatial relationships with their source CENOZOIC metavolcanic lithologies. A few thin bands of felsic metavolcanics map-area. occur within the flow piles and on Island CC a distinctive pyro ^ Hannigan Boy QUATERNARY clastic volcanic breccia is intimately mixed with coarse poorly i /x ^ L PLEISTOCENE AND RECENT sorted conglomerate. The mixed breccia-conglomerate is com Swamp peat, lacustrine clay and silt, stream sand and posed of angular to rounded fragments of quartz feldspar por © ^ gravel phyry, rhyolite porphyry and minor mafic metavolcanics in a REFERENCES Lodgement and ablation till, esker sand and gravel, rubbly, spinifex-textured, amygdaloidal, ultramafic matrix and varved glaciolacustrine clay and silt appears to be stratigraphically related to one or more volcanic centres occurring to the southeast in Skead Township (Hewitt Chagnon, J.Y. UNCONFORMITY 2%-V\j S ^ © 1949; Thomson 1947). The metavolcanic sequence is unconfor- 1968: Quinze Lake-Barriere Lake Area, Temiscaminque County; i ©i s, ©. PRECAMBRIAN mably overlain by and partially interbedded with Early Pre Quebec Dept. Natural Resources, Geol. Rept. 134, 101 p. (l ©©i © V L. Buies LATE PRECAMBRIAN cambrian (preTimiskaming) metasediments consisting of steeply and 1 map. MAFIC INTRUSIVE ROCKS (KEEWATIN) dipping wacke, siltstone, slate, argillite and minor conglomeratic Ferguson, S.A. and Freeman, E.B. Raven lenses. In southern Rattray Township, small inliersof Pontiac-type 1978: Ontario Occurrences of Float, Placer Gold, and other 9a Augite diabase metasediments such as occurjn Pense and Brethour Townships to heavy minerals; Ontario Geological Survey MDC 17, 9b Olivine diabase the south (Lovell 1977) consist of quartz-feldspar-biotite-a- 214p. 9c Differentiated diabasic rocks; lamprophyre mphibole schist with lesser intercalated and fragmented black INTRUSIVE CONTACT slaty beds. Further east towards the Quebec border, the Early Hewitt, D.F. Precambrian Pontiac-type metasediments become more meta 1949: Geology of Skead Township, Larder Lake Area; Ontario MIDDLE PRECAMBRIAN morphosed and gneissic in the vicinity of a wide lit-par-lit contact Dept. Mines, Vol.58, pt.6, 43p. Accompanied by Map HURONIAN SUPERGROUP 1949-3, scale 1 inch to 1,000 feet. zone with Early Precambrian Algoman-type felsic intrusive rocks COBALT GROUP comprising a large granitic batholith or massif (Chagnon 1968; Lovell, H.L. Gowganda Formation Wilson 1912). On the west side of the map-area another Early 1974: Bayly Township, District of Timiskaming: p.107-109 in Coleman Member Precambrian intrusive body composed of differentiated syenite Summary of Field Work, 1974 by the Geological Branch, re-intruded by granite cuts through the previously described MP59, edited by V.G. Milne, and K.D. Card, 705p. 8a Arenite lithosome: light grey to green massive feldspathic arenite, quartzose arenite; inter metavolcanics and metasediments. Small sills, dikes and irregular Lovell, H.L. and Caine, T.W. calated with pink arkose pebble conglomerate, shaped intrusions of varitextured syenite gabbro, diorite, and 1970: Rift Valley; Ontario Dept. Mines, minor argillite lamprophyre of uncertain age relationships are also present. MP39, 16p. HEARST TP thin sand, clay 8b Diamictite lithosome: blue grey sparkling sac- More than 75 percent of the map-area is underlain by a sub Lovell, H.L. and Frey, E.D. charoidal paraconglomerate intergraded with stantial thickness of Middle Precambrian Coleman member sedi 1977: Pense Township, District of Timiskaming; Ontario Geo pebbly argillite, arkose, feldspathic wacke, mentary rocks which unconformably overlie the Early Pre logical Survey Prelim. Map P.1222, Geol. Ser., scale minor orthoconglomerate cambrian and comprise the lowest unit in the Gowganda For 1:1 5,840 or 1 inch to 1A mile. Geology 1972. mation of the Cobalt Group, Huronian Supergroup sedimentary PARALLEL UNCONFORMITY (DISCONFORMITY) Lovell, H.L. and Ploeger, F.R. rocks. These flat-lying to gently dipping, low grade to unmeta- 8c Rhythmite-turbidite lithosome: dull-grey to 1978: 1977 Report of the Kirkland Lake Resident Geologist; morphosed epiclastic rocks outcrop along a prominent series of sparkling blue-grey laminated or massive ar Ontario Geological Survey Miscellaneous Paper MP78,. northeast-trending ridges made up of buttes, mesas and cuestas gillite-wacke, layered, massive and graded arkoses p.66-81. bounded by steep terraced bluffs which rise some 50 m to and wackes, dropped clasts 150 m above the level of Larder and Raven Lakes. The sub- Pretorious, D.A. linear system of ridges are the erosional remnants of extensive 1974: The Nature bf the Witwatersrand Gold-Uranium Deposits; UNCONFORMITY and thick deposits of sediment laid down in an elongate steep- University of Witwatersrand Johannesburg, Econ. Geol. EARLY PRECAMBRIAN sided trough interpreted by the author as a zeugogeosyncline or Research Unit, Information Circular No. 86, p.50. FELSIC INTRUSIVE ROCKS block-faulted rift structure marginal to an intracratonic auto Ridler, R.H. 7a Granitic rocks geosyncline! depression to the south (the Cobalt Embayment). 1970: Relationship of Mineralization to Volcanic Stratigraphy 7b Syenitic rocks The lowest exposed portions of Coleman member rocks consist in the Kirkland Larder Lakes Area, Ontario; Geol. Assoc. of generally thinly bedded to laminated rhythmic sequences of INTRUSIVE CONTACT Canadian Proceedings, Vol.21, p.32-42. glaciolacustrine argillite-wacke with dropped clasts interbedded INTERMEDIATE TO ULTRAMAFIC INTRUSIVE ROCKS 2 with massive, cross-bedded and graded fluviodeltaic rocks of Savage, W.S. arkosic composition. Sedimentary structures including current 1964: Mineral Resources and Mining Properties in the Kirkland 6 Differentiated syenite, lamprophyre: gabbro, bedding, ripple marks, and load casts are well developed. Ar Lake-Larder Lake Area; Ont. Dept. Mines Mineral Re diorite; lesser pyroxenite gillaceous units tend to increase in volume up the section to the sources Circular No. 3, 105p. INTRUSIVE CONTACT level where a disconformity is reached. Above this disconformity Thomson, J.E. UPPER METASEDIMENTS there occurs a massive to poorly bedded heterogeneous assemblage 1947: Geology of Hearst and McFadden Townships; Ontario of vertically and laterally intergraded sedimentary rocks deposited Dept. Mines, Vol. 56, Pt.8, 34p. (Publ. 1949). Accomp 5 Feldspathic wacke, argillite; minor slate and under conditions of tectonic instability. The most abundant rock anied by Map No. 1947-1, scale 1 inch to 1,000 feet. arkosic conglomerate type above the disconformity is a very poorly sorted to non Wilson, M.E. UNCONFORMITY? sorted, polymictic, matrix-supported paraconglomerate with 1912: Geology and Economic Resources of the Larder Lake predominantly felsic intrusive pebble-to cobble-sized clasts and METAVOLCANICS (KEEWATIN) District, Ontario and Adjoining Portions of Pontiac fewer metavolcanic and metasedimentary fragments derived from ULTRAMAFIC AND MAFIC METAVOLCANICS (PICHE?) Early Precambrian rocks from northerly terrains. Volume per County, Quebec; Geological Survey of Canada, Mem. 4 Dark green to black iron-rich tholeiitic basalt, centage of clasts is generally less than 15 percent and often less 17-E,Maps31A, 32A. medium grey to green magnesium-rich tholeiitic than 5 percent and most of the rock is a tilloid diamictite with a Wolfe, W.J. basalt consisting of fine-grained massive flows, well indurated matrix of poorly sorted fine sand, rock flour, or 1976,: "Gold in Early Precambrian Superior Province Plutonic pillow flows, pillow breccia, flow breccia, tuff- mud-silt which is subarkosic to wacke and rarely bedded. Inter Rocks; The Relation of Geochemical Abundance and Adamson breccia, variolitic flows and gabbroic and dia bedded and intergraded with the paraconglomerate are lesser Concentration to Exploitable Levels; Ontario Div. Mines, basic textured flows. volumes of irregularly distributed argillite-wacke and arkosic GS17,11p. 3 Dark green, black or light grey ultramafic ko rocks with occasional clast-supported framework orthocon matiite and basaltic komatiite consisting of mass glomerate lenses. Compositional and textural maturity and /Be-/,/"©; ive and pillowed flows, pyroxenitic textured flow sorting generally increase in the upper levels of the exposed interiors, serpentinite. Middle Precambrian section where occurrences of light grey and green medium-to fine-grained massive orthoquartzites were FELSIC METAVOLCANICS observed. 2 Light yellow to buff or pink to light green rhy- olite-dacite massive varitextured calc-alkalic STRUCTURAL GEOLOGY: The belt of Early Precambrian meta GEOLOGICAL AND MINING SYMBOLS volcanics and metasediments in the map-area makes up-part of a flows, alloclastic volcanic breccia, tuff-breccia, large arcuate fold belt extending into Hearst, Skead, Bayly and cherty tuff, minor sulphide interflow; intrusive Mcvittie Townships. Lava flows in the area generally strike north; Glacial striae. equivalents. however, several phases of tight folding, numerous faults, and UNCONFORMITY contact zones with intrusive bodies give rise to local variations. Esker. J.OWER METASEDIMENTS (PONTIAC) Prominent faulting in the area occurs in two main trends; 1 Quartz-feldspar-biotite-amphibole schist, feld north to northeastward and northwestward, with the latter group Small bedrock outcrop. spathic wacke, slate (Lake Timiskaming Rift System, Lovell and Caine 1970) off setting the north-northeastward trending faults, the former being Area of bedrock outcrop. 1 Former time-stratigraphic classification; may in part be pre-Huronian. more prominent in effecting sttike displacement, shear, schistosity, rthin fine sand S, pebbly till 2 Uncertain time-stratigraphic relationships, may in part be flows. jointing and resultant fault scarp formation. Thomson (1947) has Bedding, horizontal. described some of the fault structures in the area (eg. Milky Creek + Fault, Southwest McFadden Fault), and a major lineament de Bedding, top unknown; (inclined, vertical). Hebert signated as the Larder River Fault in Bayly Township (Lovell 1974) extends.aiong the northeast-trending water course into the Lava flow; top in direction of arrow. map-area. The major structural element which controlled de position of the Middle Precambrian Coleman rocks is an elongate ^*~\ Vi © depression which first appeared in the underlying Early Pre- Direction of palaeocurrent. f i/Jii-- SOURCES OF INFORMATION Schistosity; (horizontal, inclined, vertical). Geology by Z.L. Mandziuk and J. Patterson, 1978. fine sand Resident Geologist©sFiles, Ontario Ministry of Natural Resources, Kirkland Foliation; (horizontal, inclined, vertical). Lake. METAL AND MINERAL REFERENCES Base-map derived from Forest Resources Inventory, Division of Lands, Geological boundary, observed. / /- —x l Ontario Ministry of Natural Resources. Au ...... Gold py ...... Pyrite ^-feb,8c ©N N, OGS Maps 336, 1947-1, 2205, P.885, P.1228; Baker, C.L. (1978 in pre cp...... Chalcopyrite qcv . . . Quartz carbonate vein Geological boundary, position interpreted. paration) Quaternary Geology of the Larder Lake Area, District of Cu ...... Copper qc...... Quartz vein Timiskaming. gf ...... Graphite S . . .Sulphide mineralization Fault; (observed, assumed). Spot indicates down GSC Maps 31a, 32a, 44-29, 47G, 1494G, 20119G, 20125G throw side, arrows indicate horizontal movement. Pb ...... Lead Zn ...... Zinc Goes e t (-rK Magnetic declination approximately 70 17 W, 1978. po ...... Pyrrhotite f^y o/ vj Lineament. Lake**-*, This map is published with the permission of E.G. Pye, Director, Ontario +SS Jointing; (horizontal, inclined, vertical). Geological Survey. LIST OF PROPERTIES AND OCCURRENCES Anticline, syncline, with plunge. RATTRAY TP, P2245 Issued 1979

DH Drill hole; (vertical, inclined). Colex Exploration Incorporated [1977] * Information from this publication may be quoted if credit is given. It is Geophysical Engineering Limited [1976] * recommended that reference to this map be made in the following form: Carbonatized rock. Lacasse, L. (Selco option) Mandziuk, Z.L. and Patterson, J.G. Mathias Occurrence (Kerr Addison option [1956] *) 1979: McFadden Township Area, District of Timiskaming; Ontario * A date in square brackets denotes last year of exploration Geological Survey Prelim. Map P.2244, Geological Ser., Scale activity. 1:15 840 or 1 inch to Y* mile. Geology 1978. 48000©30" 48000©36"