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Ontario Division of Mines
HONOURABLE LEO BERNIER, Minister of Natural Resources Dr. J. K. REYNOLDS, Deputy Minister of Natural Resources G. A. Jewett, Executive Director, Division of Mines E. Q. Pye, Director, Geological Branch
Geology of Clifford and Ben Nevis Townships District of Cochrane
By
L. S. Jensen
Geoscience Report 132
TORONTO 1975 ODM 1971
Publications of the Ontario Division of Mines and price list are obtainable through the Ontario Ministry of Natural Resources, Map Unit, Public Service Centre, Parliament Buildings, Queen©s Park, Toronto, Ontario and The Ontario Government Bookstore 880 Bay Street, Toronto, Ontario.
Orders for publications should be accompanied by cheque, or money order, payable to Treasurer of Ontario.
Parts of this publication may be quoted if credit is given to the Ontario Division of Mines. It is recommended that reference to this report be made in the following form:
Jensen, L.S. 1975: Geology of Clifford and Ben Nevis Townships, District of Cochrane; Ontario Div. Mines, GR132, 55p. Accompanied by Map 2283, scale l inch to Vz mile.
Car-1000-75 CONTENTS
PAGE Abstract ...... v Introduction ...... l Location and Access ...... l Previous Investigations ...... l Purpose and Methods ...... 2 Acknowledgments ...... 2 Topography ...... 3 General Geology ...... 3 Table of Lithologic Units ...... 4 Precambrian ...... 5 Early Precambrian Rocks (Archean) ...... 5 Definition of Terms ...... 5 Volcanic Rocks ...... 6 Mafic Volcanic Rocks ...... 6 Basalt ...... 6 Andesitic Basalt ...... 7 Intermediate Volcanic Rocks ...... 8 Andesite ...... 9 Dacite ...... 10 Intermediate Pyroclastic Rocks ...... 11 Layered Felsic Volcanic Rocks ...... 11 Lower Felsic Volcanic Unit ...... 13 Upper Felsic Volcanic Unit ...... 15 Felsic Tuff ...... 16 Lapilli-Tuff, Tuff-Breccia, and Agglomerate ...... 16 Flow-Breccia ...... 19 Mafic and Intermediate Intrusive Rocks ...... 19 Felsic Intrusive Rocks ...... 20 Felsic Subvolcanic Rocks ...... 20 Granitic Rocks ...... ,...... 22 Middle to Late Precambrian Rocks (Proterozoic) ...... 24 Mafic Intrusive Rocks ...... 24 Diabase ...... 24 Structural Geology ...... 24 General Remarks ...... 24 Folding ...... 25 Faulting ...... 26 Bedrock Chemistry ...... 28 Geological History ...... 34 Economic Geology ...... 34 Description of Properties ...... ,...... 36 Ben Nevis Township ...... 36 Beaudry Prospect (5) ...... 36 Canagau Mines Limited (7) ...... 37 (Interprovincial, Costello, and Ehrhart Groups) ...... 37 Duvan Occurrence (8) ...... 42 Martin Prospect (9) ...... 42 Preston East Dome Mines Limited [circa 1948] (10) ...... 43 Roche Prospect (11) ...... 43 Tremblay, A. (12) ...... 44 iii PAGE Clifford Township ...... 45 Campbell J. Property (l and 6) ...... 45 (Ehrhart-Costello Group) ...... 45 Cliff Copper Incorporation [circa 1960] (2) ...... 46 Herrick Prospect (3) ...... 46 Mining Corporation of Canada Prospect (4) ...... 47 Considerations for Future Exploration ...... 48 References ...... 49 Index ...... 53
TABLES 1 Table of lithologic units ...... 4 2 Classification of pyroclastic rocks ...... 6 3 Chemical analyses of volcanic rocks ...... 29 4 Assessment information ...... 35 5 Assays from the Canagau Mine ...... 40
FIGURES 1 Key map showing location of Clifford and Ben Nevis Townships ...... ix 2 Sketch-map showing the distribution of layered felsic volcanic rocks ...... 14 3 Geological sketch-map of Clifford and Ben Nevis Townships ...... 27 4 Plots of weight percent versus normative plagioclase composition of the volcanic rocks.... 32 5 AFM diagram for volcanic rocks ...... 33 6 Differentiation diagram of volcanic rocks, Clifford and Ben Nevis Townships ...... 33 7 Geological plan, section of Canagau Mines Property ...... 38
PHOTOGRAPHS 1 Photomicrograph of prehnite, quartz and pumpellyite in amygdule ...... 10 2 Photomicrograph of perlitic fractures in rock fragment of intermediate tuff ...... 12 3 Photomicrograph showing two generations of hydrogarnet in chlorite ...... 12 4 Photomicrograph of pisolitic tuff ...... 13 5 Bedded rhyolite tuff ...... 17 6 Photomicrograph of unaltered crystal tuff ...... 17 7 Photomicrograph of crystal tuff ...... 18 8 Photomicrograph of olivine diabase ...... 25 9 Buildings on Canagau Mines Limited property ...... 37 10 Photomicrograph of shaft vein mineralization on Canagau Mines Limited property .... .39 11 Photomicrograph of Ehrhart vein mineralization at Canagau Mines Limited property .. .41
GEOLOGICAL MAP (back pocket) Map 2283 (coloured) Clifford and Ben Nevis Townships, District of Cochrane. Scale: l inch to ^ mile (1:31,680).
IV ABSTRACT
Clifford and Ben Nevis Townships are underlain by Early Precambrian (Archean) volcanic and intrusive rocks that are part of the Timmins-Kirkland Lake-Noranda Volcanic Belt. The volcanic rocks are a sequence of lava flows and pyroclastic units that are mafic and intermediate in composition toward the base of the sequence, felsic toward the top of the sequence, and have a calc-alkaline chemical affinity. Widely distributed sills, stocks, and dikes of mafic and intermediate intrusive rocks cut the volcanic rocks. An intrusive complex, con sisting of granitic stocks and one rhyolitic body cut the volcanic sequence and the mafic and intermediate intrusive rocks in the centre of the map-area, near the axis of a domal anticline.
Figure 1-Key map showing locations of Clif ford and Ben Nevis Townships. Scale: 1:50 miles (1:3,168,000). (Dis trict boundary was moved south one row of townships 7 May 1974.)
The domal anticline is flanked by a complimentary syncline to the north, east, and south. Distribution of felsic pyroclastic rocks around the intrusive complex suggests a possible vol canic centre. Block faulting is locally confined to the domal anticline, and also is regional to the map-area. Regional deformation and alteration of the Precambrian rocks are restricted to non-penetrative concentric folding, and to metamorphism under zeolite facies conditions. Metamorphism under albite-epidote hornfels facies conditions occurred near the intrusive contacts of the granitic stocks. Chalcopyrite, galena, and sphalerite are replacement-type deposits along shear zones in the felsic volcanic rocks. Gold and molybdenite are associated with the sulphide minerals near the granitic stocks. Away from the stocks, gold and silver are associated with sulphide minerals in the felsic volcanic rocks. No economic sulphide deposits have been found in the map-area. Some sand and gravel is utilized for local road construction.
Geology of Clifford and Ben Nevis Townships District of Cochrane By L S. Jensen 1
INTRODUCTION
Location and Access
Clifford and Ben Nevis Townships are two adjacent six-mile square (16 km2 ) townships located 15 miles (24.1 km) north of Larder Lake in the District of Cochrane, Ontario. Access to the west and south parts of the map-area can be gained by two gravel-surfaced roads that extend north from Highway 66. A private logging road, an extension of the Esker Lake Park road, goes into the Esker Lakes Provincial Park and into the west part of Clifford Township. The other road is a forest access road that extends north from Larder Lake Station into the southern part of Ben Nevis Township. This road is presently under construction and will, in the future, provide access to the central and northern parts of Ben Nevis Township. Float-equipped aircraft can operate on Keith, Webster, and Pontiac Lakes. Kennedy, Side, Car, Verna and Keith Lakes provide access to the central part of the map-area for small boats. All canoe portages are in good condition in the area.
Previous Investigations
The area was first investigated by W.J. Wilson in 1901 (Wilson 1901, p. 119A- 120A) who examined the rocks along the canoe route from Kennedy Lake north through Verna, Keith, and Webster Lakes. Then, a reconnaissance followed of the "Ben Nevis Area" by CW. Knight in 1919, which included Clifford and Ben Nevis Townships. A second reconnaissance survey was made by T.L. Gledhill in 1927 of the Ben Nevis area. iGeologist, Ontario Division of Mines, Toronto. Manuscript accepted for publication by the Chief Geologist, May 28, 1971. Clifford and Ben Nevis Townships
Since then, the only publications directly involving the area are GSC Aeromagnetic Maps 46G, and 47G, and ODM-GSC Aeromagnetic Maps 289G (Revised) and 295G (Revised). Prospectors discovered several small base-metal and gold occurrences in Clifford and Ben Nevis Townships after the discovery of gold in Larder Lake in 1906. Exploration has continued until the present with the emphasis on base-metal occurrences. A summary of assessment work submitted to the Ontario Division of Mines is shown on Table 4. Thomson (1941, 1946, 1948a, and 1948b) mapped the main gold producing zones in the Kirkland Lake-Larder Lake region. Townships adjoining Clifford and Ben Nevis were mapped as follows: Arnold and Katrine by Hogg (1964); Bernhardt and Morrisette by Rupert and Lovell (1970); Melba and Bisley by Jensen (1969a and 1969b); and Pontiac and Ossian by Jensen (1971a and 1971b). Studies on the volcanic rocks of the Kirkland Lake area were conducted by Goodwin (1965, 1967), Baragar and Goodwin (1969), and Ridler (1970).
Purpose and Methods
This report is a study of the geology of Clifford and Ben Nevis Townships. The purpose of the survey was to determine the nature of the bedrock, and to obtain informa tion which might lead to further economic development. Field work was done during the summer of 1969- Geological information derived from pace-and-compass traverses was plotted on air photographs obtained from the Air Photo Library, Administrative Services, Ontario Ministry of Natural Resources. Field mapping was carried out at a scale of l inch to 1,320 feet (1:15,840) using base maps prepared by the Cartography Section, Ontario Division of Lands, Ministry of Natural Resources. The base maps were published later as Preliminary Maps, P. 692 Clifford Township and P. 693 Ben Nevis Township at a scale of l inch to V4 mile (1:15,840), (Jensen 1971 c and d). Traverses were made to all outcrops visible on the air photo graphs, and at intervals of V4 mile (0.4 km) where outcrops were not visible on the air photographs. During the 1969 field season, 1,400 hand specimens were collected; from these 270 thin sections and 30 whole-rock analyses were done by the University of Saskatchewan and by the Mineral Research Branch, Ontario Division of Mines. Most thin-sections that were cut formed part of a University of Saskatchewan Master©s research project by P. Bateman. The whole-rock analyses are shown in Table 3. During the microscopic examination of the thin-sections, modes were determined by point-counting 500 points per thin-section. The anorthite composition of plagioclase was determined by obtaining the angle of extinction of combined Carlsbad-albite twinning on sections cut normal to (010). Sodium cobaltinitrate stain was used to identify potassic feldspar in the felsic rocks.
Acknowledgments
Assistance in the field was given by A. Cooper, H. Sui, and K. Wells. Mr. D. Hunt, the senior assistant, was responsible for part of the geological mapping. Much of the laboratory work was done by P. Bateman for the author, the latter person studied this area as a partial requirement for a University of Saskatchewan Master©s Degree. Special thanks are extended to Dr. F. F. Langford of the Department of Geological Sciences, University of Saskatchewan, who acted as a thesis advisor for the author during the research; his assistance with, and criticism of this report were valuable assets to the author.
Topography
Clifford and Ben Nevis Townships are covered by till and glacial outwash deposits through which bedrock is exposed. Extensive outcrop areas occur in Ben Nevis Town ship and in the east half of Clifford Township. Such outcrop gives the areas around Verna Lake and Pushkin Lake, and the northern part of Ben Nevis Township, a local relief of 500 to 600 feet (150 to 180 m). Elsewhere, the local relief is from 30 to 50 feet (9 to 15 m). In the western half of Clifford Township a thick layer of outwash sand, gravel, and dune sand (along the east flank of the Munro Esker) covers most of the outcrop. Many short eskers from V2-niile to 2-miles (0.8 km to 3.2 km) long occur in the eastern part of the map-area. Eskers and minor outwash areas formed by the Pleistocene glaciation are potential sources of sand and gravel in the area. The height-of-land between the Atlantic and Arctic watersheds crosses the map-area. The map-area is drained to the south by the Misema River System and to the north by the Magusi River System. Vegetation consists mostly of jack pine, spruce, poplar, birch, and balsam. Recent logging operations have concentrated on spruce and poplar in Clifford Township. Ben Nevis Township has not yet been logged.
GENERAL GEOLOGY
Clifford and Ben Nevis Townships are underlain by the Early Precambrian (Archean) volcanic belt, the "Abitibi Belt", extending from the Noranda area in Quebec to west of Timmins in Ontario. Bodies and sills of mafic, intermediate, and felsic intrusive rocks cut the volcanic rocks. Dikes of diabase intrude all the older Precambrian rocks. Pleistocene deposits consisting of sand, gravel, and till were deposited during the retreat of the Wisconsinan ice. Recent deposits consist of peat and alluvium. The sequence of geological events is summarized in the Table of Lithologic Units, Table 1. The layered Early Precambrian assemblage is a volcanic sequence with a few interbedded sedimentary rocks (see Figures 2 and 3). Intermediate and felsic volcanic rocks predominate in this sequence, with some mafic volcanic rocks occurring in the central part of Clifford Township. Chemical analyses of the volcanic rocks show that they belong to a calc-alkaline series ( see Table 3 and Figure 6). Most of the intrusive rocks are sills, bodies and dikes of mafic, intermediate and granitic rocks that cut the layered volcanic sequence. Some bodies and dikes of rhyoda- Clifford and Ben Nevis Townships
l TABLE OF LITHOLOGIC UNITS FOR THE Table l CLIFFORD-BEN NEVIS AREA.
CENOZOIC
QUATERNARY Recent Peat, alluvium. Pleistocene Gravel, sand, till and clay. Unconformity
PRECAMBRIAN MIDDLE TO LATE PRECAMBRIAN (PROTEROZOIC)
MAFIC INTRUSIVE ROCKS Olivine diabase, quartz diabase. Intrusive contact
EARLY PRECAMBRIAN (ARCHEAN)
FELSIC INTRUSIVE ROCKS Granodiorite, quartz diorite, diorite, syenite, feldspar porphyry and quartz-feldspar porphyry. Intrusive contact
MAFIC TO INTERMEDIATE INTRUSIVE ROCKS Gabbro, quartz gabbro, hornblende gabbro and diorite. Intrusive contact
VOLCANIC ROCKS Felsic Volcanic Rocks Rhyodacite and rhyolite: Massive, flow-breccia, tuff-breccia, tuff and lapilli-tuff. Intermediate Volcanic Rocks Andesite and dacite: Massive, pillowed, flow-breccia, tuff, argillite. Mafic Volcanic Rocks Basalt: Massive, pillowed, flow-breccia, tuff-breccia. cite and rhyolite also cut the volcanic sequence. The range in composition of the intrusive rocks is similar to that of the volcanic rocks. Also, the volcanic and intrusive rocks with comparable compositions show similar areal distribution patterns. The intermediate intrusive rocks, like the intermediate volcanic rocks, are widely distributed in the map- area. They occur mainly as sills and stocks that cut the intermediate volcanic lava flows. The granitic and rhyolitic intrusions are largely concentrated in the central part of the map-area, and are flanked by layered felsic volcanic rocks. The bedrock of both townships has been affected by low-grade regional meta morphism under zeolite facies conditions; within 1,500 feet (400 m) of the granitic intrusions, the extrusive rocks have been metamorphosed under albite-epidote hornfels facies conditions (Turner and Verhoogen I960). Structurally, the map-area is located in the centre of a synclinorium that opens to the east. In the centre of the map-area, a domal anticline occurs, which is flanked to the north, east, and south by a complementary syncline. A north-trending anticline occurs in the eastern part of Ben Nevis Township, and a northeast-trending syncline occurs in the southeastern part of Ben Nevis Township. A number of radial and short northwest- and northeast-striking faults occur in Ben Nevis and Clifford Townships near the intrusive complex. A few regional northeast- and north-trending faults transect the map-area.
PRECAMBRIAN
Early Precambrian Rocks (Archean)
Definition of Terms
In this study, the boundaries between map-units correspond to changes in composi tion of the volcanic sequence that are based on field and petrographic studies. Each map- unit is composed of one or more flows and pyroclastic members, and has a restricted chemical composition. Each flow probably represents the effusion of one type of lava that took place during a period of volcanic activity. Three types of flows of lava are recognized by the author: massive, pillow, and flow- breccia. Pillow lava flow-units consist of an agglomerate of rounded pillows which fit upon one another; and the small intervening spaces between the pillows are filled with materials of volcanic and sedimentary origin (MacDonald 1967, p. 27). The individual pillows have a fine-grained selvage and an amygdaloidal interior. In most of the volcanic rocks, the pillows are elliptical, and are from l foot to 4 feet (0.3 m to 1.2 m) in maximum dimension. The tops of the pillows have smooth curved surfaces, and their bottoms have tails which are pointed downward perpendicular to the longest axis of the pillow. Flow-breccia forms flows in which fragments of hardened lava are incorporated as solid fragments in the still liquid parts of the same lava (Fisher I960). These frag ments vary from angular to subrounded in shape, and form from 40 to 80 percent of the rock. Massive flow-units are composed of homogeneous lava in which pillows and fragments are absent. The pyroclastic rocks comprise tuff, lapilli-tuff, tuff-breccia, and agglomerate. The materials which form these rocks are given in Table 2. Clifford and Ben Nevis Townships
Table 2 CLASSIFICATION OF PYROCLASTIC ROCKS (AFTER FISHER 1966).
VOLCANIC EJECTA
Bombs Larger than 64 mm Agglomerate
Lapilli 64 mm to 2 mm Lapilli tuff
Ash (vitric, crystal and lithic fragments) 2 mm to 1/256 mm Tuffs Dust less than l /256 mm
Unsorted blocks, lapilli, ash and dust Larger than 64 mm to less than 1/256 mm Tuff breccia
The nomenclature of the plutonic rocks used in this report is that used by geologists of the Ontario Division of Mines (Ayres 1972). The chemically analyzed volcanic rocks are classified according to the method described by Irvine and Baragar (1971). Meta morphic facies nomenclature corresponds to that used by Turner and Verhoogen (I960), and Fyfe et al. (1958).
VOLCANIC ROCKS
Mafic Volcanic Rocks
The mafic volcanic rocks consist of layered basalt and andesitic basalt. Basalt is magnetic, black, aphanitic, and has a rusty weathered surface. Andesitic basalt is non magnetic, dark grey to dark green, porphyritic and has a dull, greenish grey weathered surface. The andesitic basalts are interlayered with the basalts and with the intermediate volcanic rocks.
Basalt
Two mafic volcanic map-units, predominantly basalt, occur in the east-central part of Clifford Township (see Map 2283 in back pocket). The first unit is located on the northern and southern limbs of an eastward-trending domal anticline whose axis is intruded by granitic rocks of the Clifford Stock. South of the Clifford Stock the unit strikes east 4,000 feet (1,200 m) to the boundary between Clifford and Ben Nevis Townships, where the flow strikes north and northeast. North of the Clifford Stock, the flow strikes westward from Keith Lake for 2 miles (3.2 km). At the surface the apparent thickness of the flow ranges from 800 feet to 1,200 feet (240 m to 370 m) and the dip of the flow is from 800 to 85 0 S, south of the Clifford Stock, and is from 700 to 800 N, north of the Clifford Stock. On the south limb of the domal anticline a second predominantly basalt unit occurs 1,000 feet (300 m) south of the first mafic volcanic unit, and is interlayered between two felsic volcanic units. This map-unit strikes east for 2 miles (3.2 km) with a steep dip to the south, and ranges from 200 feet to 400 feet (60 m to 120 m) in thickness. The approximate area underlain by these two mafic volcanic map-units is shown on Geological Survey of Canada Aeromagnetic Map 46G by the 2,200 gamma isomagnetic contour line. 6 The basaltic rocks consist of massive and pillowed flows. The pillows in the pillowed flows are circular to slightly elongate in shape and are from 2 feet to 5 feet (0.6 m to 1.5 m) in diameter. These pillows are characterized by their strongly weathered rusty selvages. The selvages are from l inch to 3 inches (2.5 cm to 7.6 cm) thick, and have pillow fragments in their thicker portions. Inside the selvages, many of the pillows have amygdules from l mm to 3 mm in size filled with calcite, chlorite, and epidote. The pillowed flow-units are from 100 feet to 200 feet (30 m to 60 m) thick. The massive basalt flow-units are homogeneous black aphanitic rocks that range from 10 feet to 50 feet (3 m to 15 m) in thickness, in which pillows and fragments are absent. Many of them have dark green or rusty margins up to 2 inches (5.0 cm) thick along their upper and lower contacts. Amygdules from l mm to 3 mm are abundant in the upper 6 inches (15.2 cm) of the massive flow-units. Basalt flows in the map-area are located near the Clifford Stock and have been metamorphosed under albite-epidote hornfels facies conditions (Turner and Verhoogen I960, p. 509-511); as were other rock types near the Clifford Stock. The basalt has been partly assimilated by the granodiorite magma to form a contaminated zone that is considered by the author to be part of the Clifford Stock. At the contact between the basalt and the Clifford Stock, grains of biotite, hornblende, and feldspar as much as 2 mm in length are developed in the selvages of the basalt pillows. For distances of as much as 50 feet (15 m) from the contact with the stock, basalt is silicified, and cut by numerous veinlets of quartz. Within the basalt, "clots" of epidote as large as 64 mm in size were observed. At distances of as much as 800 feet (244 m) from the contact, numerous veins of epidote from l mm to 20 mm wide, occur along fractures and joints in the basalt. Many of the epidote veins have small amounts of quartz, calcite, magnetite, and pyrite. The basalt is recrystallized and consists of 40 to 50 percent tremolite, 30 to 35 percent plagioclase (An10-An,5), 5 to 10 percent epidote, and 5 to 10 percent magnetite. Minor amounts of quartz, pyrite, uralite, and chlorite are visible in some basalts. The texture consists of interlocking subhedral tremolite and plagioclase laths that are from 10 microns to 50 microns long in a matrix of epidote, magnetite, quartz, uralite, and chlorite. Some of the epidote, magnetite, and pyrite grains are 25 microns in maximum dimension.
Andesitic Basalt
Flow-units of dark grey to dark green andesitic basalt occur intercalated with black basalt in the east-central part of Clifford Township, and as a single map-unit in the northwest part of Ben Nevis Township that strikes east and dips from 300 to 400S. The length of exposure is 4,000 feet (1,200 m) and the minimum thickness is 1,500 feet (460 m). The total extent of the flow is not known because of faulting in the area. The andesitic basalt occurs predominantly as massive and pillowed flow-units. Some units of flow-breccia and lapilli-tuff of andesitic basalt composition are intercalated with the pillowed flow-units in Clifford Township. The pillows are elliptical and are 2 feet to 5 feet (0.6 m to 1.5 m) in length and l foot to 3 feet (0.3 to 0.9 m) wide. They are characterized by strongly weathered, dark green selvages that range from Vi to 2 inches (13 mm to 5.0 cm) in thickness. The pillow tops have smooth curvatures, and their bottoms have tails pointing downward between the underlying pillows. Clifford and Ben Nevis Townships
The flow-breccia is composed of 75 to 80 percent subangular blocks and fragments that range from Vi inch to 8 inches (13 mm to 20.3 cm) in size cemented together by andesitic basalt lava. Many blocks are portions of broken pillows. On the weathered surfaces, the edges of the fragments and blocks show a lighter colour than the matrix or fragments. The lapilli-tuff (andesitic basalt in composition) is a dark green to black rock which contains 10 to 20 percent lapilli. The fragments stand out 0.5 mm-2 mm from the matrix on the weathered surface. The matrix is composed of rock fragments ranging from 0.1 mm to l mm in size; detrital grains of magnetite, plagioclase, and quartz ranging from 20 microns to 100 microns in size; and pisolith-like masses of chlorite. Like the other mafic volcanic rocks in Clifford Township, the lapilli-tuff composed of andesitic basalt has been partly recrystallized to form secondary plagioclase (Anio-Anis), calcite, and minor epidote. The massive flow-units form homogeneous..rocks from 20 feet to 100 feet (6 m to 30 m) thick. The tops of the individual lava flows are characterized by dark green irregular selvages that are 2 inches to 3 inches (5.0 cm to 7.6 cm) thick; below the top of the flow the rock is aphanitic and amygdaloidal. In the centre of the flows the grain size increases to l mm and the rock has the appearance of a fine-grained gabbro. In the northwest part of Ben Nevis Township the andesitic basalt consists of 20 to 25 percent clinopyroxene, 40 to 45 percent secondary plagioclase (An()5-An10 ), 20 to 25 percent chlorite, 5 to 10 percent calcite, and accessory quartz, pyrite, and magnetite. The matrix is composed of calcite and chlorite and contains amygdules filled with calcite; phenocrysts of plagioclase from 20 microns to 100 microns in size replaced by calcite, albite, chlorite, and grains of partly altered pyroxene from 10 microns to 20 microns in size. Amygdules l mm to 5 mm in size are abundant throughout these rocks. In Clifford Township, the andesitic basalt has been metamorphosed under albite- epidote hornfels facies conditions (Turner and Verhoogen I960, p. 509-511). It consists of 25 to 30 percent actinolite and tremolite, 40 to 45 percent secondary plagioclase (Anou-Ariio), 5 to 10 percent chlorite, 5 to 10 percent epidote, 2 to 3 percent quartz, 3 to 5 percent magnetite and minor pyrite. The texture consists of interlocking sub hedral tremolite and feldspar laths from 5 microns to 50 microns long in a matrix of uralite, quartz and albite. Disseminated epidote, magnetite, and pyrite as much as 25 microns in size, and phenocrysts of plagioclase as much as 0.5 mm in size replaced by calcite, chlorite, albite, and epidote occur in the rock. A whole-rock analysis of andesitic basalt is shown in Table 3.
Intermediate Volcanic Rocks
Intermediate volcanic rocks, medium grey and green to light grey and green, con stitute 60 percent of the total bedrock in the map-area. These rocks, for mapping pur poses, were djvided into andesite and dacite. Nevertheless, these rocks vary from low-iron tholeiitic basalt and calc-alkaline basalt to calc-alkaline andesite and dacite (see Section on "Bedrock Chemistry"). These rocks also form interlayered lava flows and pyroclastic units. Andesite forms predominantly massive and pillowed lava flows, and is mainly in the lower part of the volcanic sequence in the northern part of the map-area. Massive 8 and pillowed flows of dacite are in nearly equal proportions with pyroclastic units of dacite. The latter are mostly in the upper part of the volcanic sequence, with the felsic volcanic stratigraphic units in the central part of the map-area. The intermediate volcanic flows are from 100 feet to 1,500 feet (30 m to 460 m) thick and extend for distances of l mile to 5 miles (1.6 km to 8.0 km). Flow-units of massive, pillowed, and flow-breccia lava from 10 feet to 100 feet (3 m to 30 m) thick comprise the intermediate volcanic flows. Most of the flows extend for distances of l mile to 5 miles (1.6 km to 8.0 km). The pyroclastic units are composed of tuff, lapilli-tuff, and agglomerate. The pyroclastic units are from 200 feet to 1,200 feet (60 m to 370 m) thick and extend for distances of l mile to 10 miles (1.6 km to 16 km). The intermediate volcanic rocks are virtually unaffected by penetrative deformation and recrystallization, and their primary structures and textures are well preserved.
Andesite
Andesitic rocks are dark grey to dark green, aphanitic, and have smooth, medium grey to light green weathered surfaces. The massive flow-units compose about 30 percent of the andesite, and are homogeneous lava flows in which pillows and rock fragments are absent, except at the upper and lower contacts of the lava flows. Many of the massive flows grade upward into pillow flow-units. The pillows are elliptical, and are from l foot to 2 feet (0.3 m to 0.6 m) in diameter. The tops of the pillows have smooth curvatures and their bottoms have tails pointed downward perpendicular to the longest axes of the pillows. On the outcrop, the light-coloured pillows have dark green selvages from Vi inch to l inch (13 mm to 25 mm) thick that are soft, and more deeply weathered than the rock inside the pillow. Spaces between the pillows contain subangular andesite frag ments. Andesitic flow-breccia contains andesite fragments of the same composition and colour as the matrix. Weathering around the edges of the fragments renders their size, shape, orientation, and quantity readily observable in the field. The flow-breccia typically contains from 70 to 80 percent subangular to subrounded fragments that are from Vi inch to 12 inches (13 mm to 30.5 cm) in size. Many of the smaller fragments are oriented parallel to the surfaces of the larger fragments. The mineral composition of the andesitic rocks is 60 to 70 percent plagioclase (Ansr,-4o), 20 to 25 percent augite, with accessory amounts of quartz, magnetite, and pyrite. Andesite has a porphyritic texture with phenocrysts of zoned plagioclase (An.-,o to An3ft ) as much as 0.5 mm in length in a felt-like or pilotaxitic ground mass. Amyg- dules from l mm to 10 mm in diameter filled with quartz, calcite, and chlorite occur in the andesitic rocks. In some andesite flows the plagioclase and augite grains are partly altered to chlorite, calcite, saussurite, albite, and quartz. Much of the alteration is probably the result of propylitization by deuteric solutions. In other flows pumpellyite and prehnite fill the amygdules and replace the plagioclase, indicating that metamorphism under zeolitic facies conditions (Turner and Verhoogen I960, p. 532) has occurred, particularly in the central and southern parts of the map-area (Photo l). Near mafic and felsic intrusive rocks, the andesitic rocks have been altered under albite-epidote hornfels facies conditions. They have been altered to homogeneous green 9 Clifford and Ben Nevis Townships
ODM9055 Photo 1-Photomicrograph of pumpellyite, quartz and prehnite in an amygdule. Sample taken 500 feet (150 m) north of Shuba Lake, Ben Nevis Township (Plain Polarised Light).
rocks cut by numerous irregular veinlets of epidote, calcite, and quartz. Epidote, chlorite or tremolite, calcite, albite, and quartz replaced plagioclase and augite, and destroyed the original texture of the rock.
Dacite
Dacite is a light grey to light green hard aphanitic rock with a light grey weathered surface. Dacitic lava flows contain flow-units of massive lava, pillow lava, and flow-breccia. The pillow flow-units are 50 feet to 500 feet (15m to 150 m) thick and compose about 70 percent of the dacite flows. The pillows are less well developed than those of the more mafic volcanic flows. The long axes of the pillows are twice the length of their short axes, giving them a "mattress-shaped" appearance. They are from 2 feet to 5 feet (0.6 m to 1.5 m) in length. The pillow selvages weather dark brown to dark green, causing the light green to light grey pillows to show up on the outcrop surface. The selvages are from Ys inch to 34 inch (8.5 mm to 16.8 mm) thick. The flow-units of flow-breccia are composed of 70 to 80 percent angular to sub angular fragments which are from Yz inch to 18 inches (1.3 cm to 45.7 cm) in size. The flow breccias are up to 100 feet (30 m) thick and are up to 3 miles (4.8 km) in length. The fragments show up on the outcrop©s surface in much the same way as they do in andesitic flow-breccia. Some are broken pillow fragments in which pillow selvages are preserved. 10 Dacite is composed of 70 to 80 percent plagioclase (An25-An40 ), 5 to 10 percent augite, and 5 to 15 percent quartz. Accessory minerals are pyrite and magnetite. The dacitic rocks have zoned phenocrysts of plagioclase (An3o-An4o) as much as 0.5 mm long that form clusters from l to 2 mm in diameter, and quartz phenocrysts as much as 0.1 mm in diameter. The phenocrysts occur in a quartzo-feldspathic, a spherulitic, or a felty groundmass. Amygdules in dacite are l mm to 3 mm in maximum dimensions, and are filled with quartz and minor chlorite. In altered dacites, the plagioclase and augite grains have been partly replaced by calcite, albite, and chlorite.
Intermediate Pyroclastic Rocks
Intermediate pyroclastic rocks of andesitic and dacitic composition form tuff, lapilli- tuff, and agglomerate. They are extensive in the central and eastern parts of Ben Nevis Townships where they are concentrated in the transition zones between the felsic strati graphic units and intermediate lava flows. They also occur among the intermediate lava flows in the remainder of the map-area. These pyroclastic rocks are similar in composi tion, colour and hardness to the adjacent varied flow-units. The tuff, lapilli-tuff, and agglomerate occur intercalated with one another as layers that vary from 5 feet to 100 feet (1.5 m to 30 m) in thickness with no apparent relation between the diameter of the fragments and the thickness of the bed. Rock fragments of variable size and shape are randomly distributed; sorting is rarely observed in these rocks. The tuffaceous rocks are light grey granular rocks with rusty brown weathered sur faces on which there are small angular to round fragments of volcanic rock, crystal frag ments, and spiculate bodies. They consist of chloritic and silicified glass, crystal plagioclase (An25-An;{r,) and volcanic fragments less than 2 mm in size. Volcanic dust and the minerals calcite, chlorite, and pyrite compose the matrix. The chloritic and silicified glass fragments have relict perlitic fractures (Photo 2). Hydrogarnets are developed in some chloritic glass-like fragments (Photo 3). The rocks consist of 20 to 40 percent matrix and 60 to 80 percent fragments. The lapilli-tuff is a light grey rock with dacitic fragments and oval grains from l mm to 4 mm in size on the fresh and weathered surfaces. The dacitic fragments are sub angular to subrounded, and the oval grains are possibly pisoliths formed by the accretion of volcanic ash and dust (Photo 4). The fragments and oval grains are set in a matrix of calcite, chlorite, and volcanic ash and dust. Agglomerate consists of bomb-sized dacite fragments set in a tuffaceous matrix which form as much as 50 percent of the rock. The fragments range from Ys inch to 10 inches (3 mm to 25.4 cm) in maximum dimension, and are more felsic, harder, more resistant and lighter coloured than the enclosing matrix. In the agglomerates exposed on Keith Lake the fragments are contorted, elongated, and have dark green selvages Yi inch (13 mm) thick.
Layered Felsic Volcanic Rocks
The layered felsic volcanic rocks are predominantly pyroclastic rocks with a few intercalated flow-breccias that are felsic in composition. The felsic volcanic rocks form 11 Clifford and Ben Nevis Townships
ODM9056 Photo 2-Photomicrograph of perlitic fractures in rock fragment of intermediate tuff 2,000 feet (600 m) northwest of Horlock Lake, Ben Nevis Township (Plain Polarised Light x 17).
ODM9057 Photo 3-Photomicrograph showing two generations of hydrogarnet in chlorite, 1,000 feet (300 m) south of Merritt Lake, Ben Nevis Township (Plain Polarised Light x 15). 12 ODM9058 Photo 4-Photomicrograph of pisolithic tuff, 2,000 feet (600 m) northeast of Marten Lake, Clifford Township (Plain Polarised Light x 17). two stratigraphically distinct units, a lower and an upper unit in the volcanic sequence. Their relative stratigraphic positions are determined by pillow top determinations in the intermediate volcanic rocks. Each unit can be traced separately by the lithology of the intervening units. Both stratigraphic units consist of light-coloured aphanitic rocks, have a white or cream-tinted weathered surface, and are porphyritic in places. The rocks comprise tuff, lapilli-tuff, tuff-breccia, agglomerate, and flow-breccia. In many places the felsic tuff- breccia grades upward and laterally into intermediate tuff-breccia and agglomerate. This change is most pronounced in the central part of Ben Nevis Township, being noted by a decrease in the number of felsic rock fragments, as well as by a gradual change in composition of the matrix and the rock fragments. Many felsic volcanic rocks are sheared, the foliation being nearly parallel to the strike of the rocks.
Lower Felsic Volcanic Unit
The lower felsic unit is exposed on both limbs of the syncline which encloses the domal anticline and the Clifford Granitic Stock between Keith and Verna Lakes (Figure 2; see Figure 3). On the inner limb toward the Clifford Stock, the lower unit strikes N70 0E and curves east from a point l mile (1.6 km) north of the centre of the stock to the southeast shore of Keith Lake. Here the unit curves to strike N600W and continues to the southeast shore of Mary Lake where it is intruded by gabbro. At 13 Clifford and Ben Nevis Townships
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14 Purdy Lake, the lower unit curves sharply and strikes southwest, where it is again cut by the gabbro. The lower unit continues southwest from the north corner of Verna Lake to the boundary between Clifford and Ben Nevis Townships, where the strike of the lower unit curves west toward a point 1A mile (0.8 km) southwest of the Clifford Granitic Stock. Here, the lower felsic unit is repeated 1,000 feet (300 m) to the south because of an east-striking fault. The total length of exposure of the lower unit on the inner limb of the syncline is approximately 11 miles (17.7 km). On the outer limb of the syncline, the lower felsic volcanic unit is represented by a unit of intermediate pyroclastic rock that contains a few felsic fragments at a point 2,000 feet (600 m) northeast of Rat Lake in Clifford Township. From here, the unit strikes S800 E for 3 Vi miles (5.6 km) to Bolan Lake over which distance the unit becomes felsic. At Bolan Lake the lower unit strikes S700 E for 1^/2 miles (2.4 km) to the Mur dock Creek-Kennedy Lake Fault. On the south side of the Murdock Creek-Kennedy Lake Fault the unit strikes S300 E for 11/2 miles (2.4 km) where it curves sharply eastward in the hinge zone of a north-trending anticline and continues at N500 E for another 2 miles (3.2 km). The lower unit probably continues eastward into Pontiac Township where a similar unit of felsic volcanic rock is exposed for 6 miles (9-7 km) near the eastern margin of a large felsic volcanic plug (Jensen 1971a). The lower felsic unit dips steeply outward from the axis of the domal anticline on the inner limb of the syncline and ranges from 200 to 1,000 feet (60 to 300 m) in thickness. On the north limb of the syncline, the unit dips 500 to 600S and ranges from 400 to 1,000 feet (120 to 300 m) in thickness.
Upper Felsic Volcanic Unit
The upper felsic volcanic unit occurs near the axis of the syncline that encloses the domal anticline. At a point l 1/? miles (2.4 km) north of the Clifford Granitic Stock, the upper unit bifurcates along the axis of the syncline and strikes due east, and then curves southward to strike S600 E on both sides of the axis of the syncline for 3 Vi miles (5.6 km) to the Murdock Creek-Kennedy Lake Fault. On the side of the axis that is closest to the Clifford Stock, and south of the Murdock Creek-Kennedy Lake Fault, the unit strikes southeast and curves south and southwest around the domal anticline for 2 miles (3.2 km). The unit is then offset to the south by a northwest-striking fault. West of the fault, the unit strikes west for 5 miles (8.0 km) where it is again offset l mile (1.6 km) by several north-trending faults. From here, the upper felsic unit strikes west for 5 miles (8 km) across the south part of Clifford Township. On the eastern limb of the syncline, in central Ben Nevis Township, the upper felsic unit forms a south-trending lens 2 miles (3.2 km) long and 2,000 feet (600 m) wide. In the south part of the map-area the upper felsic unit disappears at a point l mile (1.6 km) northeast of Pushkin Lake and probably reappears at Car Lake on the southern boundary of Clifford Township. The upper unit ranges from 400 feet to 1,500 feet (120 to 460 m) in thickness; the thickest portions are north and south of the Clifford Granitic Stock and in central Ben Nevis Township around the hinge zone of the domal anticline. A unit of felsic pyroclastic rock strikes northwest from the Little Misema River in the southern part of Ben Nevis Township. This unit is exposed for approximately 2,500 15 Clifford and Ben Nevis Townships
feet (760 m) and is about 600 feet (180 m) thick. It is not known whether this unit is a continuation of the upper or lower felsic unit.
Felsic Tuff
Felsic tuff of rhyodacite and rhyolite composition is aphanitic, yellowish, greenish, and in places, pink. This weathered surface shows a white, pink, or cream tint, and where pyritic, a rusty colour. The tuff forms finely bedded, cherty rocks and a soft, non- bedded, strongly carbonatized rock. The finely bedded tuff is best exposed 500 feet (150 m) north of the shaft on the Canagau Mines Limited property (Photo 5). Here, it is a siliceous rock which has been extensively fractured by shearing. The rock is composed of light coloured layers 0.5 cm to 70 cm thick, separated by green laminae l mm to 5 mm thick. The layers consist of 75 to 85 percent quartz and albite, 6 to 8 percent sericite, 2 to 3 percent chlorite, 2 to 3 percent pyrite, and 2 percent plagioclase (An^o-An^,) laths. The texture consists of plagioclase laths 0.1 mm to 5 mm long in a matrix of interlocking quartz and albite grains from 15 microns to 30 microns in size, and disseminated pyrite and sericite from l micron to 5 microns in size. The laminae are composed mainly of sericite and chlorite. The chemical composition of similar rock 2,000 feet (600 m) south of the shaft, is shown in Table 3 ( see Table 3). Most of the tuff has been sheared and transformed into light green sericite schist with a soapy luster. Some is enriched with ankerite which gives it a dull creamy colour. The sericite schist consists of 50 to 70 percent quartz and albite, 10 to 15 percent sericite, 5 to 10 percent pyrite, and 5 to 10 percent calcite. The texture consists of quartz and albite-rich augen that are from 5 mm to 20 mm in length and are enclosed by thin laminae of sericite and minor chlorite. Plagioclase laths are 0.1 mm to 3 mm in length, and are replaced by calcite, albite, and sericite. Plagioclase occurs in the augen which mainly consist of quartz and albite and also forms individual augen. Calcite occurs in the shadows of the augen. The carbonatized tuff consists of 10 to 40 percent calcite and ankerite, 30 to 60 percent quartz and albite, 5 to 10 percent pyrite, and 2 to 3 percent sericite. It generally is a massive rock in which occur calcite and zeolite grains l mm to 5 mm in size are pseudomorphic after plagioclase.
Lapilli-Tuff, Tuff-Breccia, and Agglomerate
Lapilli-tuff, tuff-breccia, and agglomerate occur intercalated with the felsic tuff. They are light green to cream coloured rocks and are generally schistose. They are formed of 10 to 60 percent macro-fragments which are more resistant and lighter coloured than the enclosing matrix. The fragments in the lapilli-tuff consist of subangular to subrounded rock fragments 2 mm to 3 cm in size set in a matrix of feldspar fragments and lithic fragments from 0.1 mm to l mm in size. The matrix is cemented by calcite, quartz, chlorite and sericite. The lithic fragments consist of aphanitic felsic volcanic rock which may contain quartz 16 ODM9059 Photo 5-Bedded rhyolite tuff on the property of Canagau Mines Limited, facing southwest 500 feet (150 m) northwest of shaft.
ODM9060 Photo 6-Photomicrograph of unaltered crystal tuff 4,200 feet (1,280 m) southwest of Marten Lake, Clifford Township (Crossed Nicols x 10). 17 Clifford and Ben Nevis Townships
ODM9061 Photo 7-Photomicrograph of crystal tuff, 1,000 feet (300 m) southwest of Petit Lake, Clifford Township (Plain Polarised Light x 10). and plagioclase phenocrysts (Photo 6). Calcite and chlorite commonly fill voids formed between the matrix and fragments. The rock fragments and crystal fragments in the schistose lapilli-tuff form augen which are enclosed by thin laminae of sericite and chlorite. The matrix is partly pre served along with the fragments in the augen structures (Photo 7). The tuff-breccia consists of angular to subrounded fragments from 2 inches to 10 inches (5 cm to 25 cm) in size that occur with fragments of lapilli size and ash size. These are present in greatly varying proportions with little or no sorting present in them. Most of the fragments are felsic in composition with or without phenocrysts of quartz and feldspar. In a few outcrops of the felsic tuff-breccia, fragments of dacite are common, and in the outcrops south of the granodiorite exposures are fragments of basalt that form l to 2 percent of the rock. In the sheared tuff-breccia, the large fragments show little or no deformation or alteration because the shearing is mainly confined to the matrix. South of the Clifford Stock some tuff-breccia has been altered under albite-epidote hornfels facies conditions (Turner and Verhoogen I960). Here, the matrix has been extensively replaced by chlorite, albite, epidote, and sulphides. In the fragments the plagioclase phenocrysts are replaced by calcite, albite, and quartz and their matrices recrystallized. Many of the fragments are cut by veins of epidote and chlorite. Felsic agglomerate is rare in the map-area. It occurs mainly in the vicinity of Keith Lake in the lower felsic unit. The fragments are rounded to subrounded and are from 6 inches to 2 feet (15 cm to 0.6 m) in diameter. Many fragments are slightly contorted, and have dark brown selvages which are from Ys to y.\ inch ( 3 to 6 mm) thick. The fragments form 40 to 60 percent of the rock, and are separated from one another by lapilli-and ash-sized tuff material. 18 Flow-Breccia
Flow-breccia, felsic in composition, occurs intercalated with the felsic pyroclastic rocks. The best exposures are exposed northwest of Pushkin Lake in the upper felsic volcanic unit. They consist of subparallel oval fragments that are from 3 inches to 10 inches (7.6 cm to 25.4 cm) in size and are tightly packed against one another. A layer of light green sericite that is l to 3 mm thick, and less resistant to weathering than the fragments, separates the fragments from one another. Pyrite frequently occurs among the fragments and stains the outcrop a rusty brown. The fragments are aphanitic, light green to white, and contain quartz and feldspar phenocrysts. The rocks consist of the following: 10 to 15 percent plagioclase pheno- crysts (An^,, to An;io ) 0.1 mm to 5 mm long; 8 to 10 percent clear bipyramidal quartz, 0.1 mm to 3 mm in size; 30 to 70 percent secondary quartz and albite, l micron to 10 microns in size; 2 to 5 percent pyrite, 2 microns to 5 microns in size; and minor sericite, l micron to 2 microns long. Many phenocrysts are deeply embayed by the finer grained matrix, and the feldspar crystals commonly occur in clusters which are from 2 mm to 5 mm in size. The matrix consists of fractured plagioclase laths and rock fragments enclosed by sericite, quartz, and pyrite.
MAFIC AND INTERMEDIATE INTRUSIVE ROCKS
Mafic and intermediate intrusive rocks consisting of gabbro, quartz gabbro, horn blende gabbro, and diorite intruded the volcanic rocks. They form sills 500 feet to 2,000 feet (150 m to 610 m) thick, from l to 2 miles (1.6 to 3-2 km) in exposed length, and stocks 2,000 feet (600 m) to 5,000 feet (1,500 m) in maximum dimension. The sills occur mainly in the northern part of Ben Nevis Township and in the vicinity of the intrusive complex in the centre of the map-area. The sills are mainly dark green to black massive gabbro with a grain size varying from 2 to 3 mm. On the outcrop they have three sets of well-developed nearly per pendicular joints which distinguish them from the mafic volcanic rocks. Some gabbros are weakly magnetic in hand specimen. The gabbros have an ophitic texture and consist of 40 to 50 percent augite, 30 to 40 percent saussuritized and altered plagioclase, 5 to 10 percent magnetite, and as much as 2 percent quartz. The plagioclase grains are altered to calcite, zeolite, albite, and epidote. In the more strongly altered gabbros, the augite is partly replaced by uralite, serpentine, and chlorite. Most of the alteration appears to be the result of deuteric solutions. Some gabbro sills have hornblende gabbro in their upper parts or toward one end of them. Sills with hornblende gabbro occur l mile (1.6 km) north-west of the Clifford Stock in Clifford Township, and 1,000 feet (300 m) north of Audette Lake in Ben Nevis Township. The hornblende gabbro is a dark green to black massive rock, with the chief mafic mineral a greenish brown hornblende. The general mineral composition of the hornblende gabbro is 40 to 45 percent hornblende, 30 to 35 percent plagioclase (An40 to An4r,), 5 to 10 percent titaniferous magnetite, 5 to 10 percent biotite, and as much as 10 percent quartz. Hornblende forms anhedral poikilitic grains 3 to 5 mm in size that enclose subhedral plagioclase. Quartz, magnetite, and biotite occur as interstitial grains. In some hornblende gabbros, plagioclase is partly saussuritized, and hornblende and 19 Clifford and Ben Nevis Townships biotite are partly replaced by chlorite. Where the hornblende gabbro is altered, leucoxene is common along the grain boundaries of the titaniferous magnetite. Quartz gabbro is generally found in the upper parts of the thick mafic sills. In some sills in the northern part of Ben Nevis Township, quartz gabbro forms as much as 50 percent of the rock. In outcrop, the boundary between the gabbro and the quartz gabbro is gradational, and can only be distinguished by the lighter colour and higher quartz content of the quartz gabbro. Quartz gabbro is a major constituent of the intermediate stocks. In some stocks, quartz gabbro is the only rock-type; in others, it occurs with diorite. The contact between the quartz gabbro and the diorite is gradational over a distance of less than 100 feet (30 m); the diorite is in a small circular patch near the centre, or toward one side of a particular stock. The quartz gabbro is a medium to dark green massive rock and has a grain size which varies from l to 3 mm. It is characterized by a well-developed jointing. The rock consists of 25 to 30 percent augite, 45 to 50 percent plagioclase (Ani.-, to An.-,.-,), 10 to 20 percent quartz and as much as 3 percent magnetite. The mineral grains form a hypidiomorphic texture, which, in places, is partly destroyed where the plagioclase has been extensively saussuritized. Diorite is found in the quartz gabbro stocks at Rat Lake, northeast of Ranger Lake, and along the southern boundary of Clifford Township. At Rat Lake the diorite forms a southern extension of the stock. Near the neck of the extension, diorite grades into quartz gabbro. Northwest of Ranger Lake in Ben Nevis Township, diorite occurs as dikes which extend west from the main stock. In the stock along the southern boundary of Clifford Township, diorite occurs in the northern part, and to the south grades into quartz gabbro. The diorite is a dull, medium to light green massive rock which has light green to white weathered surfaces. The grain size ranges from 0.5 mm to 2 mm. The rock consists of 20 to 30 percent green hornblende, 40 to 50 percent plagioclase (An;i.-, to An i.-,), 5 to 10 percent quartz, l to 3 percent magnetite, and up to 10 percent augite. Orthoclase, biotite, apatite, chlorite, and leucoxene are accessory minerals. The texture consists of hornblende laths 0.5 mm to 2 mm in length, and plagioclase laths 0.5 mm to l mm in length, with interstitial quartz, magnetite, and accessory mineral grains. Occa sionally, plagioclase has been strongly saussuritized, and the lamellae within magnetite crystals have been replaced by leucoxene and chlorite.
FELSIC INTRUSIVE ROCKS
Felsic Subvolcanic Rocks
The subvolcanic felsic intrusive rocks intrude all the Precambrian rocks except for some Early Precambrian granitic stocks and Middle to Late Precambrian diabase dikes. Rhyolitic rocks form bodies ranging from" 1,000 to 4,000 feet (300 to 1,200 m) in maximum dimension and dikes that are 5 feet to 50 feet (1.5 m to 15 m) wide. The bodies are located between Keith and Verna Lakes, 11/2 miles (2.4 km) east northeast of Verna Lake and at Wicklan Lake in Ben Nevis Township. The dikes form single intrusions in central Clifford and Ben Nevis Townships. 20 The rhyolitic bodies are black to light grey or light green, cherty aphanitic rocks with or without phenocrysts of plagioclase and quartz. These rocks have cream to light green weathered surfaces and are either massive or strongly brecciated. The massive portions of the bodies are composed of finely fractured interlocking fragments cemented together by lighter coloured quartzo-feldspathic material and minor calcite, chlorite, sericite, and pyrite. The brecciated portions are zones from 10 feet to 200 feet (3 m to 6m) wide and are composed of 70 to 80 percent sub-rounded elongated fragments ranging from l inch to 5 inches (-2.5 to 12.7 cm) in length. The fragments show a preferred orientation parallel to more strongly weathered flowage lines indicated by oriented fine-grained sericite, chlorite, and pyrite crystals. The breccia zones show no apparent relation to the general structure of the area, and are believed to have been shears formed during the emplacement of the bodies. The bodies differ from one another in size, shape, and amount of shearing present. The body between Keith and Verna Lakes is 4,000 feet (1,200 m) in maximum dimension, and has an irregular shape. Zones of shearing are numerous in this body. The body l 1/^ miles (2.4 km) east northeast of Verna Lake is circular and is 1,000 feet (300 m) in diameter. The rocks of this body are mainly massive, finely fractured rhyolitic quartz-feldspar porphyry. The body south of the Little Misema River is circular, and has an average diameter of 4,000 feet (1,200 m). Here, the rocks are massive with breccia occurring only along the outer edges of the intrusion. In the central portions of the body the rocks are not fractured, and in small areas in the west part of the body the rocks contain large phenocrysts of pink feldspar. To the south, the body is believed to grade into fine-grained quartz-diorite in Katrine Township (Hogg 1963, Map No. 2061). The subvolcanic felsic intrusive rocks are composed of 5 to 15 percent phenocrysts of plagioclase (An^i-An^,,) 0.1 to 3 mm in size and 2 to 10 percent phenocrysts of quartz 0.1 mm to 2 mm in size. The matrix consists of quartz, albite, sericite, chlorite, and minor pyrite from l micron to 10 microns in size. The grains of plagioclase occur alone, or as interlocking clusters with clinopyroxene grains 10 microns to 20 microns in size. The quartz phenocrysts are clear bipyramids that have been rounded and embayed by the matrix. In the finely fractured rocks, the fragments have been cemented by quartzo-feldspathic material 2 microns to 10 microns in size. The fractures are 0.1 mm to 1.0 mm wide and contain fragments of broken plagioclase phenocrysts. The author thinks that the rocks were finely fractured during their emplacement. In the breccia, rhyodacite fragments and the quartz and feldspar phenocrysts form augen enclosed by sericite, calcite, chlorite, pyrite, recrystallized quartz, and albite. Chlorite and calcite are abundant in the pressure shadows of the augen of rock fragments and crystal fragments. The rhyolite dikes north of Verna Lake are either massive or strongly brecciated. The rock has a light grey to cream coloured weathered surface, or is rusty because of the weathering of pyrite and consists of: 5 to 10 percent quartz phenocrysts, 0,;1 to l mm in size; 15 to 20 percent plagioclase (Ann, to An!.-,) phenocrysts; and from 2 to 5 percent pyrite, 10 microns to 100 microns in size; and a matrix of quartz, sericite, albite, and minor chlorite. The quartz phenocrysts are clear bipyramids which are rounded and deeply embayed by the matrix. The feldspar phenocrysts occur alone or in clusters from l mm to 3 mm across. The breccia dikes (3c on Map 2283 in back pocket), are composed of 70 to 80 percent angular fragments; many fragments are triangular, rectangular and Vi inch to 2 21 Clifford and Ben Nevis Townships
inches (13 mm to 5.0 cm) in size. The matrix of the breccia dikes consists of sericite, chlorite, fractured feldspar quartz phenocrysts, and rock fragments. The quartz pheno- crysts and rock fragments stand out more strongly than the other minerals to give the dikes a very rough weathered surface. Many dikes are strongly pyritized, and phenocrysts of feldspar are replaced by calcite, chlorite, and albite. Finely disseminated sphalerite, chalcopyrite, and galena occur with the pyrite (see Tremblay, A.(12) in section on "Economic Geology"). The group of felsic dikes north of Verna Lake strikes west toward the body of sub volcanic intrusive rocks situated south of Keith Lake. The dikes have a composition very similar to the body and are possibly genetically related to it. However, the dikes cut a small intrusion of quartz diorite, which in turn cuts the body, so that the relationships between these rocks are obscure.
Granitic Rocks
Most of the granitic felsic intrusive rocks occur in the central part of the map-area. They consist of equigranular and porphyritic quartz diorite and granodiorite in the form of stocks, sills, and dikes that cut one another and the surrounding volcanic rocks. Some stocks have hybrid gabbro and diorite along their edges. The Clifford Stock is approximately 6,000 feet (1,800 m) in diameter and intruded all other rocks in the area, except for a diabase dike. The stock consists mainly of pink equigranular granodiorite which in places grades into light grey quartz diorite. On the north and east edges of the Clifford Stock the granodiorite grades into porphyritic grano diorite which is in contact with rhyolite and mafic volcanic rocks. The contact with the rhyolite and the mafic volcanic rocks is sharp, and dips from 40 to 60 degrees in all directions away from the centre of the Clifford Stock. Along the south, west, and north west edges of the stock, the granodiorite is contaminated by mafic volcanic rocks to form a border zone of hybrid gabbro and diorite. The zone is 100 to 200 feet (30 m to 60 m) wide, and grades sharply into the granodiorite. The contact between the hybrid rocks and the mafic volcanic rocks dips 75 to 85 degrees away from the centre of the stock. A stock approximately 2,000 feet (600 m) wide and 4,000 feet (1,200 m) long with granodiorite similar to the Clifford Stock occurs in the northeast part of Ben Nevis Township, northeast of the intrusive complex. Contaminated diorite is also present along the edges of this stock. Little is known about this stock because of the lack of outcrop in the area. Granodiorite in both stocks consists of 50 to 55 percent plagioclase (AnL.0 to An30 ), 10 to 12 percent orthoclase, 15 to 20 percent quartz, 10 to 12 percent hornblende, 2 to 3 percent biotite, and 3 to 4 percent chlorite. Accessory minerals include magnetite, epidote, and pyrite. Anhedral grains of quartz, 50 microns to 100 microns in size and orthoclase 0.5 to l mm in size, occur interstitially with subhedral plagioclase and hornblende laths 0.1 mm to 2 mm in length. Chlorite occurs along many of the grain boundaries. In much of the granodiorite, the orthoclase and plagioclase grains are partly kaolinized and saussuritized. Hybrid gabbro and diorite, occurring with granodiorite, are medium grey to dark grey magnetic rocks whose grain size varies from l to 2 mm. On outcrop surfaces they appear as grey granular rocks in which clots and schlieren of mafic rock material 22 occur. The clots and schlieren range from l to 10 cm in size and form 5 to 10 percent of the total rock. The general composition of the "clot-free" hybrid rocks is 40 to 50 percent plagioclase (An35 to An40 ), 5 to 10 percent quartz, 10 to 20 percent hornblende, 2 to 10 percent biotite, 5 to 7 percent magnetite, and 5 to 10 percent chlorite. Accessory minerals include orthoclase, epidote, sphene, and apatite. The clots and schlieren are composed of 60 to 65 percent hornblende, 10 to 20 percent biotite, 10 to 15 percent magnetite, and 5 to 10 percent quartz. The "clot-f ree" rocks have an igneous texture in which plagioclase, hornblende, and biotite grains from 0.5 mm to 2 mm in size, occur with interstitial quartz grains and disseminated magnetite grains from 50 to 200 microns in size. The clots and schlieren have a granoblastic texture in which recrystallized quartz grains, 10 to 50 microns in size occur in a felty matrix of hornblende and biotite grains that are from 100 to 200 microns in length. Porphyritic granodiorite [shown as quartz-feldspar porphyry on Map 2283, back pocket] not only occurs in the border zone of the stocks, but is also found in many dikes and elongated dike-like bodies, the largest of which occurs 1,800 feet (550 m) northeast of the Clifford Stock. This intrusion is 2,000 feet (600 m) wide and trends northwest for 7,000 feet (2,100 m) and cuts all other Early Precambrian rocks in the area. The dikes are 10 feet to 50 feet (3 m to 15 m) wide and have a strike which is generally perpendicular to the Clifford Stock. Some dikes are subparellel to the contact of the stock and occur 1,000 feet to 3,000 feet (300 m to 900 m) from the contact. Most of the dikes are not contaminated by their host rocks, and appear to have been intruded along faults because of their radial and semicircular pattern. The porphyritic granodiorite is a light green rock which contains 20 to 35 percent pink feldspar phenocrysts 0.5 mm to 3 mm in size; and is distinguished from the rhyodacite porphyry by its greater abundance of feldspar phenocrysts and less well developed bipyramidal quartz phenocrysts. The granodiorite has a matrix comprising 40 to 50 percent plagioclase, 10 to 20 percent quartz, 10 to 15 percent orthoclase, and 20 to 25 percent chlorite, hornblende, and biotite, and as much as 10 percent pyrite. The matrix is composed of mineral grains ranging from 10 microns to 100 microns in size, and quartz "phenocrysts" ranging from 100 microns to 300 microns in size, and plagioclase "phenocrysts" ranging from 0.2 mm to 2 mm in size. Most of the plagioclase "phenocrysts" are zoned, their cores range from An^o to An3ft and their rims are potassic. Quartz diorite, as previously mentioned, forms outcrops in the Clifford Stock. In places quartz diorite appears to grade into granodiorite. Quartz diorite is an equigranular, light grey, massive rock that consists of 50 to 60 percent plagioclase (An30 to An4o), 15 to 20 percent quartz, 20 to 25 percent hornblende, and l to 2 percent magnetite. Orthoclase, biotite, pyrite, and apatite are accessory minerals. Subhedral plagioclase grains, 0.1 to l mm in size and subhedral hornblende grains from 0.2 to 2 mm in length, occur with interstitial quartz and magnetite grains 50 microns to 200 microns in size. Where the plagioclase is extensively saussuritized, the texture is partly destroyed. A stock composed of quartz-diorite occurs north of Verna Lake. The stock is 2,000 feet (600 m) across and intrudes intermediate intrusive rocks to the south and east, and volcanic intrusive rocks to the north and west. It is cut by east-trending volcanic breccia dikes. Equigranular quartz diorite, similar to that previously described, occurs in the central and southern portions of the stock. To the north, the rocks grade into light green porphyritic quartz diorite which is composed of 30 to 40 percent plagio clase phenocrysts 0.5 mm to 5 mm in size. The matrix of the rock consists of 5 to 10 percent augite, 10 to 20 percent hornblende, 20 to 25 percent quartz, and 35 to 40 percent plagioclase (An23 to An30 ). The phenocrysts of plagioclase are zoned and have 23 Clifford and Ben Nevis Townships cores with an anorthite content as high as An40- Many of the plagioclase grains form clusters in which there are augite grains ranging in size from 20 to 100 microns. Syenite forms a west-trending dike 50 feet wide (15 m) in the south part of Clifford Township (see Map 2283 in back pocket). The syenite is red, equigranular, and has a grain size of 2 mm to 4 mm. Its composition is 60 percent perthitic orthoclase and 10 percent plagioclase (An?) which form subhedral grains 0.1 to 4 mm in size; dark green interstitial patches, 0.5 to 3 mm in size, composed of subhedral to euhedral grains of epidote, magnetite, and zircon 0.1 to 0.2 mm in size, interstitial fibrous chlorite and actinolite, form the remaining 30 percent of the rock.
Middle to Late Precambrian Rocks (Proterozoic)
MAFIC INTRUSIVE ROCKS
Diabase
Two diabase dikes occur in the map-area. One strikes N300W and extends for 3 Vi miles (5.6 km) from the south shore of Verna Lake northward to 2,500 feet (76 m) southeast of Rat Lake. The dike is 50 feet to 100 feet (15 m to 30 m) wide and consists of olivine diabase. The other dike is in central Ben Nevis Township where it strikes N600E and extends for 200 feet (60 m). It is 25 feet (7.6 m) wide and consists of altered diabase. The first dike, at Verna Lake, is a medium brownish green diabase with a grain size of l to 2 mm. It consists of 7 to 8 percent olivine, 40 to 45 percent augite, 40 to 45 percent plagioclase (An70-An80 ), 7 to 8 percent magnetite, 2 to 3 percent biotite, and accessory chlorite. The texture consists of subhedral olivine and plagioclase grains 50 to 150 microns and 0.1 mm to l mm in size respectively, enclosed in anhedral poikilitic phenocrysts of augite 0.5 mm to 2 mm in size. Magnetite grains 20 to 300 microns in size occur enclosed in augite and also form interstitial grains between biotite and chlorite grains (Photo 8). The dike is not offset by regional northeast faults and is therefore, the youngest Precambrian feature in the map-area. The second diabase dike is black, aphanitic, and olivine-f ree. It consists of 8 to 10 percent titaniferous magnetite that has been strongly altered to leucoxene, 50 to 60 percent plagioclase (An00 to An70 ), and fine needles of green amphibole.
STRUCTURAL GEOLOGY
General Remarks
The structure of the map-area is largely determined from the attitudes and tops of pillows in the lava flows, individual lava flows, and pyroclastic units which can be used as marker horizons. Lineaments that are observed readily on air photographs are indicated on Map 2283 (in back pocket) as faults because they coincide with one or 24 O DM9062 Photo 8-Photomicrograph of olivine diabase, north of Verna Lake (Plain Polarised Light x 10) Abbreviations: mag-magnetite, ov-olivine, plag-plagioclase, px-pyroxene. more of the following features; zones of shearing and brecciation, displacement of geological contacts, prominent scarps, and offsets of isomagnetic contours. The thicknesses of many volcanic flows and pyroclastic units vary several hundred feet within distances of a few thousand feet along strike. The presence of structurally undeformed pillows, amygdules, and rock fragments indicates that variation in thickness is largely a depositional feature. Because of this, and the lack of "top" indicators in the pyroclastic units near the hinge zones of many folds, the location of the traces of fold axial planes are only approximate. Measurements of the dips of faults can rarely be obtained, because streams and alluvium-filled valleys have developed along the faults. Owing to uncertainties regarding the movement along faults and the location of fold axial planes, net-slips of most faults cannot be determined accurately.
Folding
Clifford and Ben Nevis Townships are in the central part of a synclinorium which occurs north of Kirkland Lake and Larder Lake. The outer part of the synclinorium consists chiefly of mafic volcanic rocks. They have been partly mapped by Lovell (1966, 1967), Rupert and Lovell (1968a, b), and Jensen (1969a, b, 1971a, b). ODM-GSC Aeromagnetic Maps 295G (Revised), 289G (Revised), and GSC Maps 46G and 47G indicate that the mafic volcanic rocks partly underlie the townships to the north and 25 Clifford and Ben Nevis Townships south of Clifford and Ben Nevis Townships, and that the synclinorium widens and plunges ealstward. This indication is in part supported by the general strike of the volcanic rocks to the west and southwest of the map-area being southeast (Rupert and Lovell 1970, Map 2193), (Jensen 1969b, Map P.520). A diagram showing the structure of the map-area is shown in Figure 3. The style of folding is mainly concentric with the intermediate volcanic flows and pyroclastic units acting as competent units in the layered sequence. The felsic pyroclastic units show induced foliation and have acted as incompetent units, and where they occur in the hinge zones the folding is appressed. An east-trending domal anticline occurs in the centre of the map-area. Several subvolcanic felsic intrusions and the Clifford Granitic Stock were localized along the axis of this structure. The layered volcanic rocks dip steeply outward from these intru sions. A complementary syncline encloses the domal anticline to the north, east, and south. Many of the same volcanic flows and pyroclastic units can be found on both limbs of the syncline. On the limb of the syncline common to the domal anticline, the strata dip toward the axis of the syncline at angles of 70 to 85 degrees. On the limb of the syncline furthest from the Clifford Stock, the strata dip from 90 to 50 degrees toward the axis of the syncline. An anticline is located in the east part of Ben Nevis Township. In the north part of Ben Nevis Township, the fold is wide and plunges south. Its axis trends south through the Canagau Mines Limited property where the fold is much tighter along the hinge zone because of the incompetent felsic pyroclastic rocks. South of the Canagau Mines Limited property the axis of the anticline curves southwest and extends into Katrine Township with a reversed plunge. A syncline extends into the southeast corner of Ben Nevis Township from Pontiac Township. The syncline is a broad concentric fold that plunges southwest and occurs between the volcanic plug in Pontiac Township (Jensen 1971 a, b) and the anticline to the west.
Faulting
Faults in the map-area can be roughly divided into two groups: early local faults, and late regional faults. The local faults are radial and "circular" tensional faults related to the intrusive complex in Clifford Township. The radial faults are vertical and extend for less than a mile (1.6 km) outward from the intrusive complex. Many are intruded by granodiorite and porphyritic granodiorite and have an offset less than 200 feet (60 m). Disseminated pyrite is present in many of the shears and some porphyritic dikes associated with the faults. The "circular" faults occur northeast and southeast of the felsic intrusive complex in Clifford Township. Northeast of the complex, their strike ranges from N100W to N500W and they have a length that ranges from less than l mile (1.6 km) to greater than 2 miles (3.2 km); most having been cut off by the regional faults. They occur regularly at intervals of 2,000 feet to 3,000 feet (600 m to 900 m) and are vertical to subvertical. Southeast of the complex, they strike N15 0E and are partly obscured by the regional northeast faults. The "circular" faults are possibly cryptovolcanic structures caused by collapse (de Sitter 1964, p. 231-233). The fact that the Clifford Granitic Stock dips northeast and east would tend to support this conclusion and explain why these structures are not prominent west of the stock. The elongated porphyritic intrusion southwest of Keith Lake is on one of these faults. 26 I mV XI ID •S K) .c U •tt i c 1 •0 m O .U "o -s -2 ^5 10 U a. ^ 58 1 1 tt E f \ o Q \ j*. \ \ M sg* 4] Intrusive 3-Geol
.•S•5 2 3 -^ 1 W
27 Clifford and Ben Nevis Townships
The regional faults consist of two sets, northeast-striking faults and north-striking faults. Most extend outside the area or under thick overburden in the west part of Clifford Township. The northeast faults strike from N500E to N700E; the most prominent is that named by Hogg (1964) the Murdock Creek-Kennedy Lake Fault. This fault extends through Verna Lake into Pontiac Township. A branch of this fault extends southwest into Clifford Township (see Figure 2). Other northeast faults occur at Rat Lake, north of Keith Lake, at Sullivan Lake, and at Wicklan Lake. Where outcrop occurs along these faults, the rock is vertically sheared for widths of 10 feet to 50 feet (3 m to 15 m). Quartz-calcite veins from Vi inch to 2 inches (13 mm to 5 cm) wide are present in most exposed fault zones, and are accompanied by chlorite and epidote alteration. Two north-striking faults occur in the area. The first is located in the west part of Clifford Township under the Munro esker, and can only be detected by the left-lateral displacement of the isomagnetic contour lines on Aeromagnetic Map 47G (GSC 195Ib). The second is located in the southeast corner of Ben Nevis Township. It is marked by a vertical scarp, and an abrupt change in strike in the volcanic units across it; on the east side of the fault the rocks strike east, and on the west side, they strike north to northeast.
BEDROCK CHEMISTRY
Whole-rock analyses were made of thirty samples and were found to have a pre dominantly calc-alkaline chemical affinity. The rocks (Table 3) are classified by computer according to the method of Irvine and Baragar (1971). The AFM diagram and the AlgOa versus Normative Plagioclase Composition Diagram for the whole-rock analyses are shown in Figures 4 and 5. Many of the chemical-rock names differ from previous field and petrographic rock classifications (see Ayres 1972) in the intermediate group of volcanic rocks. A diagram was developed by the writer to relate the determinations of chemistry to field mapping methods based on the cation percentages of Al^Oa, FeO, Fe^On.TiOa and MgO (Figure 6). The diagram was tested on several suites of volcanic rock to separate and show the approximate differentiation trends of the calc-alkaline and tholeiitic volcanic rocks in a similar manner to the AFM Diagram (Figure 5), as well as show the colour of the rock in the field. Boundaries for basalt, andesite, dacite and rhyolite were added to the diagram and found to reflect the chemical and mineralogical composition of the rock more closely than the chemical names. Figure 6 indicates that high-iron tholeiitic basalt, basaltic andesite and light-coloured siliceous rhyolite can only be distinguished. Low- iron tholeiitic basalt, calc-alkaline basalt, and dacite cannot be identified by normal field methods on the basis of colour and hardness. The same is true of the volcanic rocks to the northeast in Dokis Township (Baragar 1968, p. 776). The intermediate volcanic rocks, medium grey and green to light grey and green, normally identified as andesite and dacite, show a wide chemical range of composition within a narrow range of colour and texture. Chemical rock names used in Irvine and Baragar©s classification (1971) tend to be more basic than would be expected from the silica content of the rocks in Nockolds (1954). A possible explanation is that alkalies were removed during the formation of clinozoisite, epidote and chlorite by deuteric alteration. This would cause an excess of anorthite to be calculated in the normative plagioclase. 28 J O Q to t- •* CO CO Ol Ol CM CO 00 o CO Oi oo CM CO co CO O CM 0 CO CM CO CO CO eo — OS co in to -* to o — o o 0 0 o 5 a in — Z
i**. eo Tj" Oi r^. co i Cft S S 5 CO O) in CM r^ co g 0 o in S 2 18 CM CM CO —* — o ^^ CO — O o o o o ~"* aa 0 8 C/3 tJ C/5 to r~ Tf to co CO 2 eo 3 CM r* 18 Tt- S 8 — o — S !J — - CM J CM i^ r* CM •* CM 10 CO — — 0 0 0 0 CM in — 0 1 Z
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O 0 in — . CO O! (O - —* in in l|g O r* co •^" in C* r*. VO — o g o eo rf o ^ CM S 2 CM CO CO (O CM O O 0 0 0 0 ~ 0 8
p o CM 0 co in f** (O in in in oE^ — CO rF CM CO S S 00 Ol CM CM tt) O cA 2 o •* O r-* r- (O .-l 0 0 0 0 o m •n O Q rj Jri in — Q ^ E C/3
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OoSO co in CM — - CM eo co (O 8 R g in to g eo (O — o g S g — CO g r: CM CM — o o o o o CM 0 S
n SAMPLE rt M NO. o. O 2 0 S- q. 0 fc o OM o D o; c O q. o- 1 .2 U. fe *5 Z if H PU* O) S U x X H 29 Clifford and Ben Nevis Townships
J ^? Tf* -*- CO CM to co O CM Tt- CO en in 5- CO — •* — CM O CM ~~m 8 8 S CO tO o — en o o o — o o 0 0 r^ O 00 o: CD z Q O — co in CM •* co r^ o — — 0 CO CM t~- S Tt- •rt- — CO — o —, CO in — -~ —— ^ Tj- (0 ^^ m --j- co CO o o o o o o CO o en ea in — en C/3 (d C/3 CO t^ co en CO CM CM o r~- CO C5 Cn in — i 8 CO en r^ O 0 r 2 O — in ~~ — in in in CO o o 0 O 0 0 Tt- ^ S 2 0 2 Z
en" o o CM CO o t^ co in O CO oo in co CM — in s •* O) CO to CO O g 2 CM CO oo ~" CO -~ CM Pu ooTt- "^in co to o o — 0 0 o o 0 S I en Z Q O to o CO Tt- in rt- CM CO Ch CM en 2 CO —H CO oo o en — o — 10 rf — CO O """* in in 10 Tj- o o 0 0 o o CO H in — 0 2 en o o CM CO CM in r^ o m CM o ~ CO [d 0 CO IO CM en t^* rf CO 0 O — o — CO S S to in —' m in in •* 0 — 0 0 o o CO Z in — 0 g z Cd aa Tf CO tO to en CM tO CM T}* en — O co 0) 8 9 S 8 2 S g 8 Q in in CM in to to CO o ~- O 0 o —• CO Z in — i 0 1 Q JgH 0 0 tO co o •n T(- tO CM Tf —— co to m o o to r^ CM en en eo en — o — CM Tt- O S w CO (O in — ' in to to o — o o o o o Tt- in — 0 8 b" Oi
"zz o s CO co o 0 en Tt- in to o CO * CM g en r^ 2 5 s s S o — ^^ ^^ ^^ ~^ Tt* ^^ Tf Tj- ,M CM o o o o O (O eo o -r *2^" in — ' ~ o
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o o o in o CO CM Tt- tO CM 1^8 — CO in r^ in CM CO in co in B 2 g C? 2 S •J 6 OS — in o (M ~- ^- CM CM 0 o o o o CM 0 s o o o r~ ~ o ^K^ o^s O 00 in to (M CO CM CO en Tt- en eo 8 CO in CO CO m en S 8 g in o m co in " — o o o O CO CO 2^8 8 — 0 1
•J z j o g in — CN in CO O CM CM O Tf CO — CO o •* to in CM CO — O — CM — r^ z ^ "^ CO 8 i^ r* ~~ CO - CO ~* o — o o 0 0 CO 0 l* < PQ < in — ^ E ^ o^u CM CO CO en r*- CO ~- rh rf (O g 2 CM in to g 8 oo — - o o o m CM S S CM S 2JS oo -- O — o ~" -~ CM O O 0 o o ~ 0 g! K td ac O 0^ O o o •o o m CO ~ CO CM 5: CM CO CM 3 in CM S eS O CO T? S S CO Tt- o —- o CM CM CM O O 0 o — 0 1
w "B • 3 Id — c •J . n O O*" d" O b 1 0 ^ o(4 b O" g s 0- Q M •S o K" 11 en < u. t^ ^5 O z * h ON CO S 0 K *2 30 Table 3 CHEMICAL ROCK NAMES AND LOCATIONS OF SAMPLES OF VOLCANIC continued ROCK, CLIFFORD AND BEN NEVIS TOWNSHIPS.
NAME" LONGITUDE* LATITUDE*
1 . Calc-alkaline dacite 79-39-13.1 48-19-15.5 2. Calc-alkaline dacite 79-39-05.4 48-19-30.5 3. Tholeiitic basalt 79-38-43.8 48-19-49.6 4. Tholeiitic basalt 79-38-30.0 48-20-09.8 5. Gale-alkaline dacite 79-39-51.5 48-18-39.3 6. Calc-alkaline basalt 79-40-36.1 48-18-08.8 7. Tholeiitic basalt 79-41-02.3 48-17-56.9 8. Tholeiitic basalt 79-39-06.9 48-17-38.9 9. Calc-alkaline andesite 79-40-36.1 48-17-04.7 10. Calc-alkaline andesite 79-04-58.4 48-17-09.3 11. Gale-alkaline andesite 79-41-08.5 48-17-18.1 12. Tholeiitic basalt 79-41-20.8 48-17-34.1 13. Calc-alkaline andesite 79-41-37.7 48-17-37.2 14. Calc-alkaline basalt 79-41-26.9 48-17-20.7 15. Calc-alkaline basalt 79-39-37 . 7 48-19-03.6 16. Calc-alkaline andesite 79-45-18.5 48-18-23.8 17. Calc-alkaline basalt 79-39-44.6 48-19-01.0 18. Tholeiitic basalt 79-45-59.2 48-18-16.0 19. Tholeiitic basalt 79-39-44.6 48-19-01.0 20.b Calc-alkaline basalt 79-46-45.5 48-18-07.8 21. Tholeiitic basalt 79-43-46.1 48-18-25.8 22. Tholeiitic dacite 79-42-36.1 48-19-15.0 23. Tholeiitic basalt 79-42-23.1 48-19-59.0 24. Calc-alkaline basalt 79-38-07.7 48-18-37.2 25. Calc-alkaline andesite 79-38-46.1 48-16-54.3 26. Calc-alkaline rhyolite 79-39-35.4 48-18-46.5 27. Calc-alkaline rhyolite 79-39-53.8 48-19-19.6 28. Calc-alkaline andesite 79-49-53.8 48-20-45.5 29. Calc-alkaline dacite 79-48-07 . 7 48-19-42.9 30. Calc-alkaline basalt 79-48-11.5 48-17-35.2
"Terminology follows classification of Irving and Baragar. bQuartz diorite. *79-39-51.5 = 79*39-51.5©. 31 Clifford and Ben Nevis Townships
Z O
o a. s O O fi s "o o o S 2 o Q. . S!*. .S-W II T cc O o ** m IS wQ." S
32 M
SMC 12854 Figure 5-AFM diagram for volcanic rocks in Clifford and Ben Nevis Townships.
FeO*Fe2O3 *TiO2
Mgd
AI203 MgO SMC 12855 Figure 6-Differentiation diagram of volcanic rocks, Clifford and Ben Nevis Townships. 33 Clifford and Ben Nevis Townships
GEOLOGICAL HISTORY
During Early Precambrian volcanism, a thick sequence of lava flows and pyroclastic units of calc-alkaline composition were deposited in a mainly subaqueous environment. In general, the volcanic rocks are mafic to intermediate at the base of the sequence, and felsic toward the top of the sequence. Gabbroic and dioritic intrusions occur throughout the area and have a similar areal distribution to the mafic and intermediate volcanic lava flows. The gabbroic and dioritic rocks have modes and chemical composition similar to the mafic and inter- medate volcanic rocks, indicating that the intrusions may have been feeders for some volcanic flows. An intrusive complex consisting of rhyodacite, granodiorite, and quartz-diorite occurs in the centre of the map-area. The distribution of the layered felsic volcanic rocks indicates that the complex may have been a centre of volcanism. Coarse felsic pyroclastic rocks and flow-breccia occur near the intrusive complex, tuff and tuff-breccia occur farther away from the intrusive complex. The structure of the area appears to be of volcanic origin, because deformation of the bedrock is limited mainly to concentric folding and local block-faulting that are probably associated with doming and subsequent collapse of the volcanic centre. These structures do not appear to have been subsequently deformed by later orogenic processes. However, some folds may have been shortened by later orogenic deformation outside the area to induce foliation in the felsic volcanic units. Metamorphism under albite-epidote-hornfels facies conditions occurs only near the contacts of the granitic intrusive rocks (Fyfe et al. 1958). Elsewhere, the bedrock was altered under zeolite facies conditions (Turner and Verhoogen I960, p. 532). Intrusion of the diabase occurred after development of the northeast-regional faults.
ECONOMIC GEOLOGY
The map-area is favourable for precious and base-metal exploration because it is located between two economically important structures, the Larder Lake Fault and the Destor-Porcupine Fault, and because it occurs in a belt of volcanic rock contiguous with that of the Noranda area in Quebec. Galena, sphalerite, chalcopyrite, and silver are in the felsic volcanic rocks in Ben Nevis Township, and molybdenite and chalcopyrite occur near the Clifford Stock. Gold is in both of the above deposits. Numerous occurrences of pyrite were found in all types of volcanic and intrusive rocks, except for the diabase dikes. Some sand and gravel deposits are utilized for local road construction. Clifford and Ben Nevis Townships were not prospected until after the discovery of gold in 1906 in Larder Lake, 15 miles (24.1 km) to the south. Recorded data concerning mineralization date back to 1928 when Gledhill surveyed the area. Little evidence of prospecting activity exists in the area before 1920. Ore minerals were found during the late 1920s. Copper, molybdenum, and gold were discovered in small amounts south and southeast of the Clifford Stock by Captain Snipe and J. Bain; copper, lead, zinc, and gold west of the Cliffwd Stock by E. O. Ehrhart and J. Martin; and copper, lead, zinc, gold, and silver in central Ben Nevis by P. Roche and E. O. Ehrhart. Most 34 b O •so :1^- 2 OS "o.o H CK •d "2 •o C/3 S" B g j h j Cd Z ^^ Z rt 2 c(A1 -— - wb ??in '-x ^ oo j* ^~- .E COzS ^™ ^ S K ^ c •^ oo"2 0 |22 2 ^ is O U — -o S If *f5I~ O 2 o 73 o; ^, c/i c/3 . "o ^ ^ B- 'C 2- 5 D < O ^ *^ o c" u g ^ CJ ^ ^ di *"sij3* z g g3 — .r oo o .!i" t* SB 6 So. E s- w* fc 5 5 to ^ "E 1 If li fj^li 2 rt 15 i e N p- C3 rt 2 u ^ o O C/3 C/? o! X —' tn ^ i O j S u- j O Q C/3 0 Q U. f- H O 5 oT 1/3 *~' s ^ J ^" U J J O •*" s Q Q ^ j ft, Q Q ^. O Q O Q C/3 O j Q Q w J Z o Q *J -f J J Q Q J &T j Q j J j o GOO O O Q Q O O O Q O O O H ^,^ Z "2 UJ C Q j o U 'o '2 rt UJ rt •d oS B *j to ^2 "o.O UJ is'0 K u C x 8 H S 8. -d .E rt z •d j S (B u i 3 J g (J U bo rt B B B B "2 S A I Q 'S . 'C Hw Q H w L. b u o. ^ a. •^s- J OS S ^" " S "~* ~ 2 k*t-1 ^; Q. Z. Q. * o Herrick, i J Cj j^G 1^ CliffCo oaO a| 3 V S ^ li 1 1 fc j te 2 S rt a C/3 < ea u .S U Q S tt OS H J rt ZUJ a. ^. E H^ NM H 0^ o Of U] u U M lo" o. Z ~ CN CO •* m fi r-. CO O) O — CM S ^ 0 D |.s 2g •O w So o rt o 1/3 i-'i t-H ^J S. z ^ s g C 1PL. c *rt M ^ f "S •c g V3 OS o" "6 fl J "o t2 P ft. rt ft. ~" 0 V CO < I X "j | || Description of Properties In the following description of properties, listed in Table 4, all information regarding diamond drilling is in the Resident Geologist's Files, Division of Mines, Ontario Min istry of Natural Resources, Kirkland Lake. All assays which are not qualified by remarks concerning their origin are filed in this office. The year in brackets, following a company or an individual is the year of ownership, option, or exploration. Subtitles indicate former names of the property. BEN NEVIS TOWNSHIP Beaudry Prospect (5)* The Beaudry property extends northeast from the Canagau Mines Limited property to the 4 and 5 mile-posts (6.4 and 8.0 km) of the eastern Ben Nevis boundary. The southwest part of the property was once part of the Interprovincial Group (Gledhill 1928, p. 24-25). A few old pits were found to indicate some work was done in the late 1920s and early 1930s. No work was reported until 1952, when Sakinaw Lake Copper and Iron Mining Limited staked a rectangular area of 23 claims adjacent to the northern limit of the Canagau Mines Limited property. A geological survey was made of the area and the property was dropped a year later. The southeast part of the property held by Sakinaw Lake Copper and Iron Mining Limited and the area to the northeast was subsequently restaked by Mr. R. Beaudry who in 1964 drilled four diamond-drill holes totalling 2,500 feet (760 m), three of them on claim L74571 adjacent to the northeast corner of the Canagau Mines Limited property, and one on claim L78075, 3,000 feet (900 m) west of the 4 mile-post (6.4 km) of the Ben Nevis Township east boundary. In 1968 two additional diamond- drill holes totalling 1,340 feet (408 m) were drilled on claim L103837 adjacent to the Canagau Mines Limited property by Mr. Beaudry. Two recent pits were also sunk on claims L78075 and L103837 (Resident Geologist's Files, Ministry of Natural Re sources, Kirkland Lake). A thick unit of rhyodacite tuff and tuff-breccia extends northeast, through the Beaudry property. The rhyodacite tuff is strongly sericitized and carbonatized and has been foliated in a northeast direction, probably by folding. In the southern part of the property are east-striking strongly rusted shear zones 10 feet to 50 feet (3m to 15m) wide, containing finely disseminated pyrite and some sphalerite and galena. Diorite dikes also occur along some of the shear zones. On claim L74571, sphalerite and galena "Number refers to property number on Map 2283 in back pocket. 36 ODM9063 Photo 9-Buildings remaining on Canagau Mines Limited property. mineralization was noted along the contact between rhyodacite and diorite during the diamond drilling. No assay results were reported. On claim L78075, chalcopyrite, silver, and pyrite were reported in andesite in the upper 500-foot (150 m) length of a diamond-drill hole. Sedimentary rocks consisting of argillite, conglomerate, and sandstone were reported from the 500-foot to 860-foot (15 m to 260 m) length of the above diamond-drill hole with some "specks" of chalcopyrite in the argillite between the 790-and 857-foot (241 and 261.4 m) levels. From the 861- to 1,340-foot (262.4 to 408 m) levels, small quantities of chalcopyrite, gold, silver, and pyrite were reported in altered andesite. No assay results were reported. Canagau Mines Limited (7) (Interprovincial, Costello, and Ehrhart Groups) Galena was discovered by P.J. Roche on claim L16200 who, with M. J. Roche staked the first claims here in 1926. In 1927, the Interprovincial Exploration Company Limited was organized and acquired 26 of these claims (formerly known as the Roche group). In 1927 surface work started and included several trenches and pits and one inclined prospect shaft 40 feet (12 m) deep near the boundary line of claims L16197 and L16200. In 1928 surface work was continued and a vertical shaft 346 feet (105.5 m) deep was sunk 120 feet (37 m) east of the prospect shaft on claim L16200. Stations were established on the 125-, 225-, and 325-foot levels (38.1, 68.6 and 99-0 m) with crosscuts to the south of the 34-, 480-, and 420-foot (10.4, 146 and 128 m) levels respectively (see Figure 7). A power house, a blacksmith's shop, a pump house, a powder house, three bunk houses, two store houses, a stable, and a boat house were 37 Clifford and Ben Nevis Townships 325 (99 m) LEVEL PLANS 125' (38 m) LEVEL Quartz and calcite vein* 225© (69 m) LEVEL 325' (99 m) LEVEL Sulphides ^-i- SECTION Feet 100 200 300 l l 50 Me t r e s Agglomerate and dacite Geological boundary; Vein breccia observed, assumed. Feldspar porphyry dike Rhyolite 4- * * 4^ *| Feldspar porphyry sill Fault SMC12856 Figure 7-Geological plan, section of Canagau Mines Property. 38 ODM9064 Photo 10-Photomicrograph of shaft vein mineralization on Canagau Mines Limited property, Ben Nevis Township. Abbreviations: cp-chalcopyrite, gangue-gangue minerals, sp- sphalerite, py-pyrite. (Reflected Light x 64). erected south of the shaft (Photo 9). Nine miles (14.5 km) of road were cut to connect with the Ossian Gold Mines to the south, and 5 miles (8.0 km) of wagon road were built to connect with the boat route at Verna Lake. In 1929 the Interprovincial Exploration Company Limited suspended work and in 1935 was declared bankrupt. In 1936, Canagau Mines Limited was incorporated to take over and further develop the property and the two groups of claims to the south, the Ehrhart and Costello Group of claims. Little is known about the early history of the Ehrhart and Costello groups except that galena, sphalerite, chalcopyrite, and arsenopyrite were discovered on the Ehrhart Group shortly before or after the discovery of galena by P.J. Roche (Gledhill 1928, p.25 and Map 28e). The writer assumes that the pits found on many of the gossan zones in and near the mineralization were diamond drilled between 1926 and 1936. In November 1936, Canagau Mine,s Limited reconditioned the mining plant on the Interprovincial Group and put a winter road through to it from Cheminis. In 1937 the shaft was dewatered and sampled. No further work was done by the company until 1946 when it carried out geological and geophysical surveys on parts of the property, and diamond drilled eight diamond-drill holes (total footage and locations not reported). In I960, ground electromagnetic and magnetometer surveys were conducted near the known zones of mineralization of the Interprovincial and Ehrhart Groups in search of further extensions of the mineralization. A small amount of surface work was done on the Interprovincial Group at this time and in 1962, the company used a bulldozer to expose additional mineralization 300 feet (90 m) northeast of the shaft. Several new rock trenches and pits were put down on the new exposures. 39 Clifford and Ben Nevis Townships g — eo r** O) 04 r* O C* . 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Abbreviations: asp-arsenopyrite, cp-chalcopyrite, gangue-gangue minerals, sp-sphalerite, py-pyrite. (Reflected Light x 64). In 1969, when the author visited the property, only bunk houses were still being maintained (see Photo 9) and the roads leading to the property were well-cut trails. The property is mainly underlain by strongly carbonatized and sericitized rhyodacite tuff and tuff-breccia. Foliation developed in the tuff and tuff-breccia strikes from S600E to due east and dips 400 to 600S and is believed to have been induced by folding near the hinge zone of a south-trending anticline. The strongest mineralization of galena, sphalerite, chalcopyrite, gold, silver, and pyrite occurs along east-striking fractures and shear zones that dip 400 to 600S. Some fracture zones have been intruded by diorite dikes 100 feet to 200 feet (30 m to 60 m) wide and the mineralization is found along the contacts between the tuff and diorite. The main vein or shaft vein is exposed on the northern slope of a 40-foot (12 m) high outcrop of rhyodacite tuff. The vein is 80 feet (24 m) long and 6 inches to 18 inches (15.2 cm to 45.7 cm) wide. The vein strikes east and dips south at 40 degrees along the contact between diorite to the north and rhyodacite tuff to the south. Surface and underground work indicates that the vein strikes east for 400 feet (120 m) and extends to a vertical depth of 325 feet (99.0 m), (Figure 7). The mineralization consists of massive iron sulphides containing galena, sphalerite, chalcopyrite, gold, and silver in which small calcite stringers and rock fragments of rhyodacite and diorite occur (Photo 10). The mineralization appears to be mainly a replacement of the rhyodacite tuff. The results of analyses of samples taken from the vein are shown in Table 5. 41 Clifford and Ben Nevis Townships A second vein of massive sulphides exposed recently by bulldozing occurs 300 feet (90 m) northeast of the shaft at surface. Galena and sphalerite are in a strongly pyritized shear zone about 4 feet (1.2 m) wide. The shear zone is at the contact between diorite to the south and rhyodacite tuff to the north and strikes N600W with a dip of 800S. East- striking cross fractures occur in which galena, sphalerite, calcite, up to 18 inches (45.7 cm) in width, are found. These cut the diorite and rhyodacite tuff. The pyritized zone has been traced for 200 feet (60 m) on the surface. Assays for the grab samples taken from the shear zone are shown in Table 5. Mineralization consisting of gold, silver, copper, galena, pyrite, arsenopyrite, and sphalerite occurs 3,000 feet (900 m) south of the shaft on claim LI2781, formerly known as the Ehrhart Property (see Photo 11). The mineralization occurs in parallel east- striking rusty shear zones that are 100 feet (30 m) apart on small outcrops of rhyodacite tuff. They both disappear under thick overburden to the east and west. The sulphides are concentrated in massive veins that vary from 6 inches to 18 inches (15.2 cm to 45.7 cm) in width and that dip vertically. One sample taken from the rock cut was assayed (see Table 5). Duvan Occurrence (8) In 1964, Duvan Copper Company Limited owned 18 contiguous claims in central Ben Nevis Township. The company did a magnetometer and an electromagnetic survey over an area extending east from the fire range tower of the Ontario Department of Lands and Forests* to the west boundary of the Canagau Mine Limited property; an area which includes the west part of the Ehrhart Group prospected in the late 1920s. No anomalies were found in the area to warrant further work and the property was dropped in 1965. Amygdules filled with chlorite and chalcopyrite are found in many of the low-lying rhyodacite outcrops in the area, which was once part of the Ehrhart Group. The chalcopyrite fillings are Ys inch to V4 inch (3 mm to 6 mm) in size and are inside a chlorite rim. One old pit, presumably sunk in the late 1920s was found on one of the chalcopyrite occurrences. Martin Prospect (9) The area between Keith Lake and Mary Lake was staked in the 1920s by J. Martin after a fissure vein containing sphalerite and galena was discovered 400 feet (120 m) east of Crooks Lake (Gledhill 1928, p.24). A pit was sunk on the vein and no further work was reported until 1946. In 1946, seven diamond-drill holes totalling 4,145 feet (1,263.4 m) were drilled to find the extension of the vein, and to investigate the gossan on the east shore of Crooks Lake held by B. Macgregor who owned the property at that time. Since then, no further work has been done in the area. Neither the fissure vein containing galena nor the pit was observed during field investigations, the low areas having been flooded by a beaver dam on Keith Creek. "The Ontario Government was reorganized into various large ministries on 1st April 1972. 42 Rhyolite breccia underlies the area west of Crooks Lake. Strongly pyritized dacite occurs on the east shore of Crooks Lake. Quartz gabbro intrudes the dacite which is in turn intruded by numerous feldspar porphyry dikes. The feldspar porphyry dikes range from less than 10 to as much as 50 feet (3 m to 15 m) wide and trend about N600W. The fissure vein is reported to be a quartz-calcite vein, 4 inches (10 cm) wide, with a strike of N700W and a vertical dip, in which galena and sphalerite are found. At surface, the vein is reported to cut quartz gabbro and, at a depth of 100 feet (30 m), pyritized dacite. The length of the vein is unknown. No assays are available and no estimates on the amount of mineralization in the vein have been reported. At the shore of Crooks Lake a gossan consisting of strongly pyritized dacite breccia occurs on the west side of the outcrop. The pyrite is finely disseminated throughout the dacite and the feldspar porphyry. A fault extending through Crooks Lake northwest toward Keith Lake is thought to occur at the contact between the rhyolite breccia and dacite breccia. Silver and gold mineralization was reported in diamond-drill hole No. 5 in pink calcite veinlets cutting the pyritized dacite (see Resident Geologist's Files, Ontario Ministry of Natural Re sources, Kirkland Lake). Preston East Dome Mines Limited [circa 1948] (10) In 1948, Preston East Dome Mines Limited owned a group of 21 claims in the centre of Ben Nevis Township adjacent to the Canagau Mines Limited property. The claim numbers were as follows: L53635-52 to L53657-59 inclusive. A geological survey, a magnetometer survey, and a diamond-drilling program of three holes totalling 1,017 feet (310.0 m) were carried out. The drilling was done to test weak anomalies found by the magnetometer survey on strike with mineralized shear zones of the Canagau Mines Limited property. Only small amounts of pyrite in rhyodacite tuff and tuff-breccia were encountered, and the property was dropped. Roche Prospect (11) The area north of Canagau Mines Limited property is believed to have been pros pected during the late 1920s, when it was part of what was known as the Interprovincial Group. No work was reported until 1952, when Sakinaw Lake Copper and Iron Mining Limited staked a rectangular area of 23 claims adjacent to Canagau Mines Limited property. In a geological report by Sakinaw Lake Copper and Iron Mining Limited it is stated that trenching was done on claims L58153-54 inclusive, and test pits were sunk on claims L57981 and L57984 prior to the company's ownership (Resident Geologist's Files, Ministry of Natural Resources, Kirkland Lake). The property was dropped by the com pany and was subsequently restaked by P. Roche. In 1964, Dome Exploration (Canada) Limited and Frobex Limited took a joint option on the property, and diamond-drilled six holes totalling 1,971 feet (600.7 m). The option was dropped by them in 1965. In 1969, the property was still held by Mr. P. Roche, who is believed to have done considerable trenching on the property; he sunk several fresh pits in the northern part of the area between I960 and 1968. 43 Clifford and Ben Nevis Townships The area is underlain mainly by rhyodacite which extends from the west into the property. In places the rhyodacite is strongly pyridzed along east-striking shear zones. Mineralization similar to that found on the Canagau Mines Limited property to the south occurs on claim L76642, 300 feet (9m) north of the southeast corner claim post. Here, an open pit 50 feet (15m) long exposes the north wall of a 30-foot (9m) long rhyoda cite outcrop in which fine-grained disseminated galena and sphalerite occur along strongly pyritized, vertical, east-striking shear planes. A sample collected from the pit by Sakinaw Copper and Iron Mining Limited, assayed 0.67 percent Pb, 0.03 percent Zn, 0.01 ounce (0.34 g/t) gold per ton, and 0.57 ounce (19.5 g/t) silver per ton. The shear zone was intersected below the surface by Frobex Limited who did diamond drilling there. In diamond-drill hole F 64-1 the shear zone was found to contain 2.75 ounces (94.3 g/t) silver per ton, 0.53 percent Pb, and 1.95 percent Zn over a core length of 23.3 feet (7.1 m), and in hole F 64-6, 1.26 ounces (43.2 g/t) gold per ton, 0.08 percent Pb, and 0.25 percent Zn over a core length of 11 feet (3.3 m) (see Resident Geologist's Files, Ontario Ministry of Natural Resources, Kirkland Lake). The north part of the property is underlain by dacitic and rhyodacitic fragmental rocks whose contact is exposed along the scarp of the Murdock Creek-Kennedy Lake Fault. Along the contact, two pits have been sunk, in which finely disseminated chalco pyrite, sphalerite, and pyrite occur. No assays or assessment work reports have been submitted on the pits. A. Tremblay Property (12) A group of nine patented claims presently owned by Mr. A. Tremblay of Kirkland Lake covers an area extending from the west boundary of Ben Nevis Township to the north end of Verna Lake. The first recorded work on the property dates back only to 1948, although the area has been prospected since the 1920s. In 1948, a visit to the property was made by W.S. Savage of the Ontario Department of Mines. In his report on the property, Savage (see Resident Geologist's Files, Ontario Ministry of Natural Resources, Kirkland Lake) described seven "showings" as follows: The first showing examined was a trench trending N-S in the SE corner of claim 44172. A contact between rhyolite to the north and coarse gabbro to the south can be seen near the centre of the trench. The rhyolite contains finely disseminated pyrite in the vicinity of the contact and rare specks of chalcopyrite occur in it adjacent to the gabbro. Tremblay's No. 2 showing is located about the centre of the SE^i of claim 42720. A pit now full of water, was sunk on a narrow shear zone in acid agglomerate. The shear strikes NE and dips 80" S. Small quartz-carbonate stringers parellel the shear and fine pyrite mineralization extends for at least 3 ft. [0.9 m] into the foot wall. The hanging wall is not exposed. A grab sample assayed |2.10 in gold. Approx. 150 ft. [45 m] south-east of No. l a deep pit (No. 3), now full of water, was put down by a former owner of the property (H. James). This pit was sunk on an irregular shatter zone in gabbro which contains many fragments of acid agglomerate. Specimens on the dump contain quartz-calcite stringers and erratically distributed pyrite and sphalerite. The continuation of the shatter zone is not well defined, but another old pit 25 ft. [7.6 m] to the east shows shattering and sulphide mineralization. 44 In claim 44171 about 400 ft. [122 m] north of the No. 3 Post a small pit (Tremblay's No. 4 showing) was put down at the SE end of a trench which strikes N 35" W. The pit is in blocky-jointed porphyritic rhyolite, rusty on the joint planes from the oxidation of finely disseminated pyrite with rare specks1 of chalcopyrite. A short distance SW from the centre of this claim (44171) another (pit (Tremblay's No. 4a) can be seen. This pit, which is now full of water, Is about 6 ft. [1.8 m] deep. It was sunk in blocky jointed fine-grained lava of intermediate composition in a zone cut by a network of small irregular stringers made up of quartz, calcite, feldspar and epidote. The main direction of jointing is N 60" E with a dip 85c S. Specimens on the dump from the pit show heavy pyrite mineralization in the wall rock adjacent to the small stringers, accompanied by silicification and considerable development of epidote. Grab samples gave a trace of gold and silver. The main showing occurs on claim 42719 near the north boundary, about 450 ft. [137 m] east of the No. 4 Post. Blocky jointing is exposed in acid agglomerate for over 100 ft. [30 m] in an E-W direction. One set of joint planes with a strike varying from N 40" E to N 650 E and dipping 850 S predominates and forms a sheeted zone with rust and sulphide mineralization in the fractures. The sheeting parallels a small band of tuff to the south. A shallow pit exposes a quartz-calcite vein 2^fc inches thick [6.3 cm] on one of these joint planes con taining irregular blebs of sphalerite. To the north east of this pit stripping and trenching shows the sheeting to extend for at least 100 ft. [30 m] to the contact of the agglomerate with diorite to the north. Pyrite and sphalerite mineralization occurs in narrow stringers in the joint planes and microscopic traces of galena were observed. Tremblay's No. 6 showing exposes a narrow rusty shear zone about one foot [0.3 m] wide, located about 300 ft. [91.4 m] south of the No. l post of claim 44170. The shear, which strikes N 76C E and dips vertical, cuts acid agglomerate. It is mineralized with pyrite and contains quartz-calcite stringers, but to date has not been sampled. CLIFFORD TOWNSHIP J. Campbell Property (1, 6) (Ehrhart-Costello Group) A group of 8 patented claims located near the 8 mile-post (13 km) on the Clifford- Ben Nevis Township line are believed to have been initially staked by E. O. Ehrhart in the 1920s. The claims were formerly known as the Ehrhart-Costello Group. In 1958, Cliff Copper Incorporated sank three diamond-drill holes totalling 1,262 feet (384.7m) on claim L61603, close to an old pit believed to be part of earlier work done by Ehrhart. The work was done to check earlier reports of chalcopyrite and gold minerali zation in the pit. No chalcopyrite and no gold mineralization was reported found in the diamond drilling, and no further work appears to have been done on the property since then. The property is held by J. Campbell (1969). The property is mainly underlain by massive rhyolite breccia and basalt. The pit occurs at the contact between fine-grained altered basalt and pyritized rhyodacite breccia. Disseminated pyrite occurs along fine fractures in the rhyodacite. No chalcopyrite was observed. 45 Clifford and Ben Nevis Townships Cliff Copper Incorporated [circa 1969] (2) In the 1940s N. Jowsey prospected an area of nine claims, numbered L53761-69 inclusive, l mile (1.6 km) west of mile post 8 (12.8 km) on the Clifford-Ben Nevis Township boundary. In 1948, the property was visited by W.S. Savage of the Ontario Department of Mines (see Resident Geologist's Files, Ministry of Natural Resources, Kirkland Lake) who described the following work: Nathan Jowsey is prospecting the east contact of . . . the granodiorite boss and the intruded Keewatin rocks on the most easterly two of his claims (53765-66) and the open claims to the north. Considerable deep trenching has been done in an endeavour to expose the granodiorite-greenstone contact on the two east claims. In I960, the property was restaked by Cliff Copper Incorporated in an effort to search for new "prospecting leads" after the unsuccessful diamond-drilling program in the adjoining property (see J. Campbell Property). The company did a geological survey and dropped the property the following year. Herrick Prospect (3) In the late 1920s, Captain Snipe found chalcopyrite and molybdenite a few chains northwest of mile-post 7 (11.3 km) on the east boundary of Clifford Township, and west of Verna Lake. In his report, Gledhill (1928, p.23 to 24) described the property as the "Brett-Trethewey Copper Prospect" and "Bain Copper Discovery" as follows: Brett-Tretheway Copper Prospect. The property of the Brett-Trethewey Mines, Limited, comprising several claims, is situated a few chains northwest of mile 7[11.2 km] on the east boundary of Clifford and west of Verna Lake. Chalcopyrite was discovered here by Captain Snipe in a brecciated and sheared •zone, after he had found the copper in nearby boulders. The chalcopyrite is ac companied by fine-grained molybdenite; and the wall rock, which is a basalt, has been altered to chlorite, quartz, and carbonate. The main showing is from 3 to 4 feet [0.91 to 1.2m] wide and has been opened up for 15 feet [4.6 m] or so along the strike. The company has started intensive exploration. The main discovery lies in a zone of shearing that strikes N.600E. This break continues farther east into Ben Nevis Township. Near the copper discovery dikes of quartz diorite were noted, some of which were hydrothermally altered. In the vicinity of this find, the dominant rocks are Keewatin basalt flows and volcanic fragmentals. The ore is probably connected with the intrusion of the nearby granodiorite boss. Just east of the Snipe find there is located a continuous1 north-south dike of quartz diabase. Outcrops of the older gabbro also show at the head of Verna Lake. The Snipe find is of particular interest because of the association of chal copyrite and molybdenite; the latter pointing to an acid magma as the parent of the copper. Bain Copper Discovery. West of the Snipe find, chalcopyrite in and near altered quartz diorite dikes was found by J. Bain, of Kirkland Lake. This chal copyrite replaces selectively spots of dark chlorite in an altered acid dike. So far only small amounts of copper mineralization and intrusive rocks is well shown. No record of the work done by Brett-Tretheway Mines Limited is available. However most of the pits and possibly some of the older diamond-drill holes on the property may have been diamond drilled by the company. 46 In 1962, V. Herrick of Kirkland Lake optioned 17 claims to Hollinger Consolidated Gold Mines Limited (now Hollinger Mines Limited) which included the property described by Gledhill. Work done by the company from 1962 to 1966 consisted of three geophysical surveys (a magnetic survey, an electromagnetic survey, and a self-potential survey); a geochemical soil survey for copper and zinc; a geological survey; and a diamond-drilling program that consisted of 24 holes totalling 9,972 feet (3,039-5 m). In 1968 the option was cancelled. Mineralization consisting of chalcopyrite and pyrite occurs at surface 2,500 feet (760 m) north, and 1,500 feet (460 m) west of the 7 mile-post (11.2 km), on the east boundary of Clifford Township, in a trench 40 feet (12 m) long on the east side of an outcrop 10 feet (3m) high. Here, pyrite and chalcopyrite occur as interstitial fillings with quartz, calcite, and chlorite between angular rhyolite fragments. Sulphide material composes 2 to 3 percent of the matrix in the form of blebs from Vi inch (1.3 cm) to 2 inches (5.1 cm) in size and as fine-grained disseminated material. Diamond drilling in the vicinity indicates that the mineralization is scattered over a distance of 6,000 feet (1,800 m) along a strike of S700W from the trench. Some chalcopyrite associated with molybdenite occurs in feldspar porphyry which cuts the rhyolite breccia and basalt. Assays of gold of as much as 0.04 oz. (1.4 g/t) per ton were obtained over short core lengths in 2 of the holes drilled (Resident Geologist's Files, Ontario Ministry of Natural Resources, Kirkland Lake). Mining Corporation of Canada Prospect (1962) (4) In 1948, four mining claims, L3H63, L31164, L31165, and L41716 were owned by Mrs. T. Brazzoni. The claims were located approximately Vi mile (0.8 km) north of the 5 mile-post (8.0 km) on the south boundary of Clifford Township. In November 1948, the owner and Dr. W.S. Savage of the Ontario Department of Mines visited the claims via a trail north from Kennedy Lake. In his report, Savage described five "showings" as follows: No. l showing . . . is a narrow irregular rusty zone, exposed for about 70 feet [21.3 m] in an E-W direction, in weakly shattered and fragmental lava. The rusty stain is due to the oxidation of fine pyrite occurring as paper thin plating on the joint planes. Low gold values were reported. The second showing is an old pit at the foot of a hill facing west in the SWV4 of claim 40716. A contact between andesite and feldspar porphyry occurs on the east wall of the pit. The contact . . . is marked by a narrow streak of rust resulting from oxidation of finely disseminated pyrite. It strikes N400 E and dips 650SE, with andesite in the foot wall. To the N around the edge of the andesite hill, several other old pits can be seen. The andesite shows blocky jointing and irregular rusty patches occur on the surfaces due to pyrite minerali zation on the joint planes. . . . the third showing exposes a 2-inch [5 cm] wide fissure vein of massive pyrite at the foot of the hill facing northeast. The strike of the vein is N340E and dips 700 SE . . . Grab samples of pyrite are said to have assayed $3.00 to $4.00 in gold. The fourth place . . . was an old pit . . . sunk on some rusty streaks in green stone cut by fine irregular porphyry stringers. A few specks of pyrite were observed but there is no record of gold values. The fifth showing is . . . pillowed lava which has been cut by numerous small quartz stringers . . . and there has been considerable development of epidote. A few feet to the north-east, part of a dark porphyry dike outcrops. 47 Clifford and Ben Nevis Townships Savage states further: No evidence of recent work was seen on these claims. When the author visited the pits, there appeared to have been no further work done on them. The pits are covered by moss and plant growth and are difficult to observe. The pits are shown on the Map 2283 (see back pocket) because they were found by the author. Observations on the pits coincide with those stated by Savage (1948), except for the occurrence of small specks of chalcopyrite in grab samples of strongly pyritized andesite taken from the rock cuts of the fourth and fifth "showing". In 1961 the property was taken over by the Mining Corporation of Canada Limited from Mr. J.O. St. Pierre. In 1962 the company conducted a geophysical survey and a diamond-drilling program of five holes totalling 1,889 feet (575.8 m) to test the geo physical anomalies. Only traces of gold and 1.12 percent copper over a core length of 0.8 feet (0.24 m) were found (Resident Geologist's Files, Ontario Ministry of Natural Resources, Kirkland Lake). The property was cancelled in 1963. Considerations for Future Exploration Much of the prospecting to date has been restricted to surface and near-surface exploration southeast of the Clifford Granitic-Stock and to the sulphide occurrences near, or on the Canagau Mines Limited property. Most of the area is still open to be explored in detail. Gledhill (1928, p.25 and 34) points out that mineralization in Clifford and Ben Nevis Townships is largely by replacement in sheared and brecciated tuff that is near, or on strike with the intrusions of granodiorite. A possible explanation for this is that the Clifford Granitic Stock which intrudes the volcanic rocks from the northeast, and the granodiorite stock in the northeast part of Ben Nevis Township are from the same magma source. Any ore-bearing solutions migrating upward would favour base- metal deposition in the less competent pyritic tuffs and tuff breccias. Factors in favour of this hypothesis are: first that base-metal sulphide minerals usually occur in strongly altered rocks, a feature not common in the rocks of the area; secondly, that the minerali zation is restricted to mainly sheared and foliated rocks; thirdly, that many of the rocks in the vicinity of the intrusive complex contain small amounts of chalcopyrite, sphalerite, molybdenite, galena, and gold. An alternative hypothesis is that some of the base-metal sulphides in the felsic volcanic rocks are syngenetic and have been later concentrated along the intrusive contacts and the nearby shear zones. Either hypothesis would suggest that the felsic volcanic rocks are the most favourable rocks to prospect in the map-area. Chalcopyrite, sphalerite, and native silver have been found on the Roche and Beaudry properties near the lower contact of the felsic volcanic rocks, which indicates that the lower contacts of felsic units should be investigated further to the south along the hinge zone of the anticline where more sulphides occur. So far this has not been done. Other favourable areas are northeast of the Clifford Granitic Stock in the southern part of Keith Lake where the rocks in places are strongly chloritized, and in the area west of the Canagau Mines Limited property where copper associated with chlorite is found in many of the outcrops. These areas may possibly indicate mineralization at depth. The felsic intrusive rocks in Clifford Township should not be overlooked, as some of the porphyritic dikes containing chlorite also contain small amounts of chalcopyrite and molybdenite. 48 REFERENCES Ayres, L.D. 1972: Guide to Granitic Rock Nomenclature used in Reports of the Ontario Division of Mines; Ontario Div. of Mines, MP52, 14p. Baragar, W.R.A. 1968: Major-Element Geochemistry of the Noranda Volcanic Belt, Quebec-Ontario. Canadian J. Earth Sci., Vol.5, No.4, pt.l, p.773-790. Baragar, W.R.A., and Goodwin, A.M. 1969: Andesites and Archean Volcanism of the Canadian Shield: p. 121-142 in Proceed ings of the Andesite Conference, A.R. McBirney, Editor, International Upper Mantle Project, Scientific Report 16, published by State of Oregon, Dept. of Geology and Mineral Industries, 193p. Boissonneau, A.N. 1966: Glacial History of Northeastern Ontario, I. The Cochrane-Hear st Area; Canadian J. Earth Sci., Vol.3, No.5, p.559-578. Brisbin, W.C., and Ediger, N.M. (Editors) 1967: A National System for Storage and Retrieval of Geological Data in Canada, National Advisory Committee on Research in the Geological Sciences, available from Geol. Surv. Canada, 175p. de Sitter, L.U. 1964: Structural Geology; McGraw-Hill Book Co., New York, San Francisco, Toronto, London, Second Edition, 551p. Fisher, R.V. 1960: Classification of Volcanic Breccias; Bull. Geol. Soc. America, Vol.71, No.7, p.973-982. 1966: Rocks Composed of Volcanic Fragments and Their Classification; Earth-Science Reviews, Vol.1, No.4, p.287-298. Fyfe, W.S., Turner, F J., and Verhoogen, J. 1958: Metamorphic Reactions and Metamorphic Facies; Geol. Soc. America, Mem.73, 259p. GSC 195la: Magusi River, Districts of Timiskaming and Cochrane, Ontario; Geol. Surv. Canada, Aeromagnetic Series, Map 46G, scale l inch to l mile. Survey July 1948. 1951b: Larder Lake, District of Timiskaming, Ontario; Geol. Survey Canada, Aeromag netic Series, Map 47G, scale l inch to l mile. Survey July 1948. Ginn, R.M., Savage, W.S., Thomson, R., Thomson, J.E., and Fenwick, K.G. 1964: Timmins-Kirkland Lake Sheet, Cochrane, Sudbury, and Timiskaming Districts; Ontario Dept. Mines, Geol. Comp. Ser., Map 2046, scale l inch to 4 miles. Compilation 1961, 1962. Gledhill, T.L. 1928: Ben Nevis, Munro, Kamiskotia, and Other Base Metal Areas, Districts of Cochrane and Timiskaming; Ontario Dept. Mines, Vol.37, pt.3, p. 1-52 (published 1929). Accompanied by Map No. 37g, scale l inch to l mile. Goodwin, A.M. 1965: Mineralized Volcanic Complexes in the Porcupine-Kirkland Lake-Noranda Region, Canada; Econ. Geol. Vol.60, p.955-971. 49 Clifford and Ben Nevis Townships 1967: Volcanic Studies in the Timmins-Kirkland Lake-Noranda Region of Ontario and Quebec; p.138-142 in Report of Activities, Part A: May to October, 1966, Geol. Surv. Canada, Paper 67-1, pt.A, 221p. Hogg, W.A. 1964: Arnold and Katrine Townships; Ontario Dept. Mines, GR29, 15p. Accompanied by Map No.2061, scale l inch to Vz mile. Irvine, T.N., and Baragar, W.R.A. 1971: A Guide to the Chemical Classification of the Common Volcanic Rocks; Canadian J. Earth Sci., Vol.8, No.5, p.523-548. Jensen, L.S. 1969a: Melba Township, District of Timiskaming; Ontario Dept. Mines, Prelim. Geol. Map No.P.519, scale l inch to V4 mile. Geology 1968. 1969b: Bisley Township, District of Timiskaming; Ontario Dept. Mines, Prelim. Geol. Map No.P520, scale l inch to V4 mile. Geology 1968, 1971a: Pontiac Township, District of Timiskaming; Ontario Dept. Mines and Northern Affairs, Prelim. Map P.629, Geol. Sen, scale l inch to V4 mile. Geology 1970. 1971b: Ossian Township, District of Timiskaming; Ontario Dept. Mines and Northern Affairs, Prelim. Map P.630, Geol. Ser., scale l inch to V4 mile. Geology 1970. 1971c: Clifford Township, District of Timiskaming; Ontario Dept. Mines, Prelim. Geol. Map No.P692, Geol. Ser., scale l inch to Y4 mile. Geology 1968. 1971d: Ben Nevis Township, District of Timiskaming; Ontario Dept. Mines, Prelim. Geol. Map No.P693, Geol. Ser., scale l inch to V4 mile. Geology 1968. 1972: Geology of Melba and Bisley Townships, District of Timiskaming; Ontario Div. Mines, GR103, 27p. Accompanied by Map 2252, scale l inch to Vi mile. Knight, C.W. 1920: Ben Nevis Gold Area; Ontario Dept. Mines, Vol.29, pt.3, p.1-27. Accompanied by Map 29e, scale l inch to \Vi miles. Lovell, H.L. 1966: Benoit Township, District of Timiskaming; Ontario Dept. Mines, Prelim. Geol. Map No.P.329, scale l inch to V* mile. Geology 1965. 1967: Maisonville Township, District of Timiskaming; Ontario Dept. Mines, Prelim. Geol. Map No.P.409, scale l inch to V* mile. Geology 1966. MacDonald, G.A. 1967: Forms and Structures of Extrusive Basaltic Rocks; p. l-61 in Basalts, The Polder- vaart Treatise on Rocks of Basaltic Composition Vol.1, Edited by H.H. Hess and A. Poldervaart, Interscience Publishers, a division of John Wiley and Sons, New York, London, Sydney, 482p. Moorhouse, W.W. 1959: The Study of Rocks in Thin Section; Harper and Brothers, New York, 514p. 1970: A Comparative Atlas of Textures of Archean and Young Volcanic Rocks; Geol. Assoc. Canada, Special Paper No.8, edited by J.J. Fawcett. Nichols, R.L. 1936: Flow-Units in Basalt; J. Geol., Vol. 44, No. 5, p.617-630. Nockolds, S.R. 1954: Average Chemical Compositions of Some Igneous Rocks; Bull. Geol. Soc. America, Vol.65, No. 10, p. 1007-1032. 50 ODM-GSC 1970a: Kirkland Lake, Timiskaming District; Ontario Dept. Mines-Geol. Surv. Canada, Aeromagnetic Map 289G (Rev.), scale l inch to l mile. Survey 1947, 1948, and 1949. 1970b: Ramore, Cochrane and Timiskaming Districts, Ontario; Ontario Dept. Mines-Ceol. Surv. Canada, Aeromagnetic Map 295G (Rev.), scale l inch to l mile. Survey 1947,1948, and 1949. Pettijohn, F.J. 1957: Sedimentary Rocks; Harper and Row, Publishers, New York, Evanston, and London, Second Edition, 718p. Ridler, R.H. 1970: Relationship of Mineralization to Volcanic Stratigraphy in the Kirkland-Larder Lakes Area, Ontario; Proc. Geol. Assoc. Canada, Vol.21, p.33-42. Rittman, A. 1962: Volcanos and Their Activity; Interscience Publishers, New York, 305p. Rupert, R.J., and Lovell, H.L. 1968a: Bernhardt Township, District of Timiskaming, Ontario Dept. Mines, Prelim. Geol. Map P.446, scale l inch to V4 mile. Geology 1967. 1968b: Morrisette Township, District of Timiskaming, Ontario Dept. Mines, Prelim. Geol. Map P447, scale l inch to V4 mile. Geology 1967. Rupert, R.J., and Lovell, H.L. 1970: Geology of Bernhardt and Morrisette Townships; Ontario Dept. Mines, GR84, 27p. Accompanied by Map 2193, scale l inch to Vi mile. Thomson, J.E. 1941: Geology of McGarry and Mcvittie Townships, Larder Lake Area; Ontario Dept. Mines, Vol.50, pt.7, p. 1-99 (published 1943). Accompanied by Maps No.SOa, and 50b, scale l inch to 1,000 feet, and Map No.50d, scale l inch to 400 feet. 1946: The Keewatin-Timiskaming Unconformity in The Kirkland Lake District; Trans. Roy Soc. Canada, Third Series, Vol.40, Sec.4, p. 113-123. 1948a: Regional Structure of the Kirkland Lake-Larder Lake Area; p.627-632 in Struc tural Geology of Canadian Ore Deposits, CIM, Jubilee Volume, 948p. 1948b: Geology of Teck Township and the Kenogami Lake Area, Kirkland Lake Gold Belt; Ontario Dept. Mines, Vol.57, pt.5, p.1-53 (published 1950). Accom panied by Map Nos. 1945-1 and 1946-1, scale l inch to 1,000 feet. Turner, F.J., and Verhoogen, J. 1960: Igneous and Metamorphic Petrology; McGraw-Hill Book Co., Inc., New York, Toronto, London, Second Edition, 694p. Wilson, W.J. 1901: Western Part of the Abitibi Region; p.H7A-130A in Summary Report, pt.A, Geol. Surv. Canada, p.271, Vol.XIV. Accompanied by Map No. 760, scale l inch to 16 miles. 51 INDEX Abitibi Belt ...... 3 Canagau Mines Ltd...... 16, 18, 26, 35, 36, Access ...... l 39, 42 Acknowledgments ...... 2 Assays ...... 40 Agglomerate ...... 11, 16-18 Assessment work, table ...... 41 Felsic ...... 18 Erhhart vein mineralization Albite-epidote hornfels facies ...... 5, 7 Photomicrograph ...... 37 Alluvium ...... 3 Geological plan, figure ...... 38 Alteration, deuteric ...... 28 Shift vein mineralization, photomicrograph.. 39 Amygdules ...... 7, 8, 9, 11, 42 Carbonatized rock ...... 16 Analysis; chemical: Car Lake ...... l, 15 Whole-rock ...... 28-33 Chalcopyrite ...... 22, 34, 37, 41, 42, AFM diagram ...... 32 44-48, passim Cation percent, figure ...... 33 Cherty rock ...... 16 Table ...... 29-31 Chlorite ...... 7, 42 Weight percent versus Classification of pyroclastic rocks ...... 6 Normative Plagioclase Cliff Copper, Inc...... 45-46 Composition diagram ...... 33 In assessment work, table ...... 35 Andesite ...... 9-10 Copper ...... 34, 36, 42 Calc-alkaline ...... 8 See also: Chalcopyrite Andesitic basalt ...... 6, 7-8 Costello and Ehrhart group ...... 37-42 passim Ankerite ...... 16 Crooks Lake ...... 42, 43 Anticline ...... 26 Cryptovolcanic structures ...... 26 Domal ...... 5, 6, 15, 26 Crystal tuff, photomicrograph: Archean ...... 5-24 Fractured ...... 17 Arsenopyrite ...... 42 Unaltered ...... 17 Assessment work, table ...... 35 Audette Lake ...... 19 Dacite ...... 10-11 Augen ...... 18 Calc-alkaline ...... 8 Albite-rich ...... 16 Description of properties ...... 36-48 Destor-Porcupine Fault ...... 34 Bain, J...... 34 Diabase: Bain Copper Discovery ...... 46 Dikes ...... 24 Basalt ...... 6-7 Olivine ...... 24 Andesitic ...... 6 Dikes ...... 22 Tholeiitic ...... 8 Breccia ...... 21 Base-metal exploration ...... 34 Base-metal sulphide minerals ...... 48 Diabase ...... 24 Beaudry properties ...... 48 Rhyolite ...... 21 Beaudry Prospect ...... 36-37 Diorite ...... 19, 20, 22, 41 In assessment work, table ...... 35 Quartz ...... 23 Bedrock chemistry ...... 28-33 Domal anticline ...... 5, 6, 15, 26 Figures ...... 32-33 Dome Exploration (Canada) Ltd...... 43 Table ...... 29-31 Drainage ...... 3 Bolan Lake ...... 15 Dune sand ...... 3 Breccia: Duvan Copper Co. Ltd...... 42 Dike ...... 21 Duvan Occurrence ...... 42 Zone ...... 21 In assessment work, table ...... 35 Brett-Trethewey Copper Prospect ...... 46 Surveys, geophysical ...... 42 Campbell, J...... 45 Ehrhart, E.O...... 34 In assessment work, table ...... 35 Ehrhart and Costello Group ...... 37-42 passim 53 Clifford and Ben Nevis Townships Ehrhart Property ...... 42 Herrick Prospect ...... 46-47 Photomicrograph ...... 41 In assessment work, table ...... 35 Eskers ...... 3 Hollinger Consolidated Gold Mines Ltd...... 47 Munro ...... 3 Hornblende gabbro ...... 19 Esker Lake Park ...... l Hybrid gabbro ...... 22 Exploration: Hydrogarnets ...... 11 Base-metal ...... 34 Photomicrograph ...... 12 Future considerations ...... 48 Intermediate Intrusive Rocks ...... 3 Faults: Intermediate Volcanic Rocks ...... 8-11 Circular ...... 26 Interprovinoial Exploration Co. Ltd. ... .37, 39 Destor-Porcupine ...... 34 Interprovincial Group ...... 36, 37-42 passim Kennedy Lake-Murdoch Creek ...... 15 Intrusive complex ...... 34 Larder Lake ...... 34 Intrusive rocks, felsic ...... 3, 20-24 Faulting ...... 26-28 Felsic agglomerate ...... 18 Keith Lake .... l, 11, 13, 18, 20, 21, 22, 42, Felsic intrusive rocks ...... 3, 20-24 43, 48 Felsic subvolcanic rocks ...... 20-22 Kennedy Lake ...... l Felsic tuff ...... 16 Kennedy Lake-Murdoch Creek Fault ...... 15 Photomicrograph ...... 17 Felsic volcanic rocks: Lapilli-tuff ...... 7, 8, 13, 16-18 Layered ...... 11, 14 Larder Lake Fault ...... 34 Unit, lower ...... 13-15 Larder Lake Station ...... l Unit, upper ...... 15-16 Layered felsic volcanic rocks, distribution of Flow: 34, 36 Flow-breccia ...... 7, 9, 10, 11, 13, 19 Lead Definition ...... 5 See also: Galena Massive ...... 5, 10 Lineaments ...... 24 Pillow ...... 5, 8, 9, 10 Lithologic units, table of ...... 4 Folding ...... 25, 26 Little Misema River ...... 15, 21 Fractures, microscopic: Perlitic ...... 11 Macgregor, B...... 42 Photomicrograph ...... 12 Mafic Intrusive Rocks ...... 3 Frobex Ltd...... 43 Mafic Volcanic Rocks ...... 6-8 Magnetite, titaniferous ...... 19 Gabbro: Magusi River ...... 3 Hornblende ...... 19 Maps, Geological, coloured ...... back pocket Hybrid ...... 22 Map, sketch geological of map area ...... 27 Quartz ...... 19, 20 Marker horizon ...... 24 Galena ...... 22, 24, 41-44 passim, 48 Martin, J...... 34, 42 Garnets: Martin Prospect ...... 42-43 See: Hydrogarnets Assessment work, table ...... 35 Mary l^ake ...... 13, 42 Geology: Massive flow units, definition ...... 5 Economic ...... 34-48 Massive lava ...... 10 History of ...... 34 Metamorphic facies: General ...... 3-33 Albite-Epidote hornfels ...... 5, 7 Structural ...... 24-28 Zeolite ...... 5 Glacial deposits: Microscopic examination, sodium cobaltinitrate. 2 Eskers ...... 3 Mining Corporation of Canada Prospect . .47-48 Sand and gravel ...... 3 In assessment work, table ...... 35 Till ...... 3 Misema River ...... 3 Molybdenite ...... 34, 46, 48 Gold ...... 34, 36, 37, 41, 42, 43, 45, 48 Munro Esker ...... 3 Gossan ...... 43 Murdock Creek-Kennedy Lake Fault ...... 15 Granitic rocks ...... 3 Granodiorite ...... 22 Olivine diabase ...... 24 Porphyritic ...... 23 Photomicrograph ...... 25 Gravel ...... 3 Ossian Gold Mines ...... 39 54 PAGE PAGE Peat ...... 3 Silver ...... 34, 36, 37, 41, 42, 43 Perlitic fractures ...... 11 Native ...... 48 Photomicrograph ...... 12 Snipe, Captain ...... 34 Phenocrysts ...... 19 Sphalerite ...... 22, 34, 36, 41-45 passim, 48 Feldspar ...... 18 Sphene ...... 23 Quartz ...... 11, 18 Structure, cryptovolcanic ...... 26 Pillows ...... 5, 7, 9, 10 Stocks: Pisoliths ...... 11 Clifford ... 6, 13, 15, 18, 19, 22, 26, 34, 48 Photomicrograph ...... 13 Quartz gabbro ...... 20 Porcupine-Destor Fault ...... 34 Subvolcanic rocks, felsic ...... 20-22 Porphyry, quartz-feldspar ...... 21 Sulphide Minerals, base-metals ...... 48 Porphyritic granodiorite ...... 23 See also: Arsenopyrite; Chalcopyrite; Galena; Pontiac Lake ...... l Molybdenite; Pyrite; Sphalerite. Prehnite ...... 9 Surveys: Photomicrograph ...... 10 Duvan Occurrence, geophysical ...... 42 Preston East Dome Mines Ltd...... 43 Preston East Dome Mines Ltd., geological, In assessment work, table ...... 35 magnetometer ...... 43 Surveys, geological, magnetometer ...... 43 Syenite ...... 24 Previous investigations ...... 1-2 Syncline ...... 26 Properties, description of ...... 36-48 Synclinorium ...... 5, 25-26 Table of ...... 35 Proterozoic ...... 24 Texture: Pumpellyite ...... 9 Ophitic ...... 19 Photomicrograph ...... 10 Pilotaxitic ...... 9 Purdy Lake ...... 15 Tholeiitic basalt ...... 8 Pushkin Lake ...... 3, 15, 19 Till ...... 3 Pyrite ...... 7, 19, 22, 26, 34, 36, 37, 41-45 Topography ...... 3 passim, 47 Tremblay, A...... 44-45 Pyroclastic rocks ...... 11 In assessment work, table ...... 35 Tuff: Quartz diorite ...... 23 Breccia ...... 5, 13, 16-18 Quartz-feldspar porphyry ...... 21 Crystal ...... 18 Quartz gabbro ...... 19, 20 Photomicrograph ...... 18 Quartz phenocrysts ...... 11 Felsic ...... 16 Photomicrograph ...... 17 Ranger Lake ...... 20 Lapilli ...... 5, 7, 8, 11, 13, 16-18 Rat Lake ...... 15, 20 Rhyodacite ...... 41 Rhyodacite ...... 5, 16, 44 Rhyolite, photomicrograph ...... 17 Tuff ...... 41 Table ...... 6 Rhyolite ...... 5, 16, 21 Roche, P...... 34, 43 Verna Lake ..... l, 3, 13, 15, 20, 21, 22, 23, Roche group ...... 37 39, 44, 46 Roche property ...... 48 Volcanic Rocks ...... 6-19 Roche Prospect ...... 43-44 Intermediate ...... 8-11 In assessment work, table ...... 35 Pyroclastic ...... 11-19 Sakinaw Lake Copper and Iron Mining Ltd. ... Webster Lake ...... l 36-43 Wicklan Lake ...... 20 Sand and gravel ...... 3 Schist, sericite ...... 16 Zeolite facies ...... 5 Sericite ...... 16, 18, 21 Zinc ...... 34, 36 Side Lake ...... l See also: Sphalerite. 55 quartz O l m m py Map 2283 J Cliffordand Ben Nevis Townships ONTARIO DIVISION OF MINES HONOURABLE LEO BERNIER, Minister of Natural Resources W. Q. MACNEE, Deputy Minister of Natural Resources G. A. Jewett, Executive Director, Division of Mines E. G. Pye, Director, Geological Branch SYMBOLS Glacial striae. TANNAHILL TOWNSHIP Esker. TIMISKAMING DISTRICT Small bedrock outcrop. Area of bedrock outcrop. Bedding, top unknown; (inclined, vertical). Lava flow; top (arrow) from pi/lows shape and packing. Schistosity; (horizontal, inclined, vertical). Geological boundary, position observed. Geological boundary, position Scale l inch to 50 miles interpreted. N.T.S. reference 3ZD/5 Fault. LEGEND Anticline, syncline, with plunge. CENOZOIC* Drill hole; (vertical, inclined). QUATERNARY , Drill hole; (projected vertically, pro jected up dip). Overburden shown. RECENT -*~*-* Peat, alluvium, PLEISTOCENE Gravel, sand, till and clay. Shaft; depth in feet. UNCONFORMITY MA Magnetic attraction. PRECAMBRIAN* MIDDLE TO LATE PRECAMBRIAN (PROTEROZOIC) Altitude in feet above mean sea level. MAFIC INTRUSIVE ROCKS 6a Olivine diabase. Muskeg or swamp. ~- 6b Quartz diabase, INTRUSIVE CONTACT Other road. C L L-F EARLY PRECAMBRIAN (ARCHEAN) FELSIC INTRUSIVE ROCKS Trail, portage, winter road. 5 Unsubdivided. fflpjmtetejto 5a Granodiorite. 5b Quartz diorite. Building. 5c Diorite, gabbro. 5d Syenite. 5e Feldspar porphyry. District boundary, approximate position 5f Quartz-feldspar porphyry. only. INTRUSIVE CONTACT Township boundary, meridian or base MAFIC TO INTERMEDIATE line, with mile posts, approximate INTRUSIVE ROCKS position only. 4 Unsubdivided. Property boundary, approximate 4a Gabbro. position only, 4b Quartz gabbro, diorite. 4c Hornblende gabbro. Surveyed line, approximate position only. INTRUSIVE CONTACT VOLCANIC ROCKS Location of mining property, surveyed. FELSIC VOLCANIC ROCKS See list of properties. 3 Unsubdivided. 3a Massive rhyodacite and rhyolite Location of mining property, unsurveyed. (shallow intrusive rocks), See list of properties. 3b Flow breccia rhyodacite and rhyolite. 3c Rhyodacite and rhyolite tuff-breccia and agglomerate. 3d Rhyodacite and rhyolite tuff and lapilli tuff. 3e Amygdaloidal rhyodacite and rhyo lite. 3f Rhyodacite and rhyolite feldspar porphyry. LIST OF PROPERTIES 3g Rhyodacite and rhyolite quartz porphyry. CLIFFORD TOWNSHIP 1. Campbell, J. INTERMEDIATE VOLCANIC ROCKS 2. Cliff Copper Incorporated, [circa 1960] 2 Unsubdivided. 3. Herrick prospect. 2a Massive andesite and dacite. 4. Mining Corporation of Canada prospect. -M ^^\( 2b Pillowed andesite and dacite. 2c Flow breccia, andesite and dacite. BEN NEVIS TOWNSHIP 2d Andesite and dacite tuff breccia and 5. Beaudry prospect. agglomerate. 6. Campbell, J. 2e Andesite and dacite tuff. 7. Canagau Mines Ltd. 2f Amygdaloidal andesite and dacite. 8. Du van occurrence. 2g Andesite and dacite feldspar por 9. Martin prospect. phyry. 10. Preston Bast Dome Mines Ltd. {circa 1948] 2h Argillite. 11. Roche prospect. 12. Tremblay, A, MAFIC VOLCANIC ROCKS 1 Unsubdivided. Ownership of properties as of December 31,1968. Date la Massive basalt and andesitic basalt. in brackets [1965] indicates year of last major work on 1b Pillowed basalt and andesitic basalt. property. For further information, see report. 1c Flow breccia basalt and andesitic basalt. 1d Basalt and basaltic andesite tuff breccia. 1e Amygdaloidal basalt and andesitic basalt. 1g Basalt and andesite feldspar por phyry. SOURCES OF INFORMATION Geology by L. S. Jensen and assistants, 1969. Ag Geology in part is tied to surveyed lines. asp Geological and geophysical mapsof mining companies. Au SoW. Geological Survey of Canada aeromagnetic map 46G. carb Carfconafe. Preliminary maps, P.692 Clifford Township and P.693 cbl Chlorite. Ben Nevis Township, scale 1 inch to V, mile, issued 1971. V Chalcopyrite. Map 2283 f •W Galena. Cartography by C. A. Love and assistants, Surveys and Mapping Branch, 1973. mo Molybdenite. po Pyrrhotite. Base map derived from maps of the Forest Resources Inventory, Surveys and Mapping Branch. CLIFFORD AND BEN NEVIS TOWNSHIPS m Pyrite. Quartz. Magnetic declination in the area was approximately TIMISKAMING DISTRICT m 10050' W.,1970. Quartz carbonate. Sphalerite. m Unconsolidated deposits. Cenozoic deposits are Scale 1:31,680 or l Inch to V2 Mile represented by the lighter coloured and uncoloured parts of the map. Chains 80 2 Miles b Bedrock geology. Outcrops and inferred extensions of each rock map unit are shown respectively in deep NOTES Metres JOOO 3 Kilometres and light tones of the same colour. Where in places, a formation /s too narrow to show colour and must be Geological mapping was done by marking recogniz Feet 1000 O 5,OCX) 10,000 Feet represented in black, a short black bar appears in the able features on air photographs or by using pace- appropriate block. and-compass methods to locate features relative to recognizable landmarks. Some township lines were sufficiently recognizable for geological survey purposes.