MINISTÉRE DE L'ÉNERGIE
ET DES RESSOURCES
DIRECTION GENERALE DE L' EXPLORATION GÉOLOGIQUE ET MINÉRALE
I
THE APATITE BELT OF WEST PORTLAND TOWNSHIP
W.W. Moorhouse
1942 DP-2
THE APATITE BELT
OF
V 1aST PORTLAND TOWNSHIP, QUEBEC - by -
W. W. M:oorhouse
III
CONTENTS
Page
Introduction 1
Acknowledgments 2
History and Development
3
Production of Apatite for the Province
of Quebec 4
Previous Geological Work
5
Mining Methods
7
Technology 8
New Developments 10
Apatite Deposits Apatite in Apatite in Apatite in Apatite in Apatite in Apatite in Apatite in
of the World 13
Russia 13
Norway 15
Spain 15
South Africa 16
South America 17
Asia 17
Australia
i8
Topography 19
General Geology 21
Grenville Rocks 21
Limestone 21
Biotite gneiss 21
Quartzite 22
Dark-coloured gneisses 23
Injected and pegmatitic gneisses 25
Pyroxenite 27
Origin of the pyroxenite 30
Pegmatite, Granite, etc. 34
Apatite 38
Origin of the apatite deposits 43
Diabase Dikes 47
Structural Geology 48
Description of Properties 50
The Ross Mountain Property 50
Little Union (Crown Hill) Property ... 52
High Rock Property 56
Cap Rock Pits 62
Big Union (Star Hill) Property 63
Brazeau Property
66
Page
Appendix
68
Analyses of Canadian Apatite
68
Sampling 72
Possibility of Further Development 74
Probable value of the ore 78
Milling 78
Development 79
Dumps
80
By-products 81
List of Illustrations
Facing Page Figure 1: Pit Number 1, Little Union property
7
Figure 2: Veinlets of quartz in biotite gneiss 21 Figure
3:
Pyroxenite interbedded with quartzite 23 Figure 4: Quartzite cut by pegmatite 23 Figure5:
Pyroxenite in contact with amphibolite 24 Figure6:
Injected sillimanite-garnet gneiss 26 Figure7:
Sillimanite garnet gneiss 26 Figure8:
Gneissic pyroxenite 27 Figure9:
Fractured pyroxenite and apatiteCO) Figure 9A: Interbanding of apatite and pyroxenite 30 Figure 10: "Leopard granite" enclosing apatite
crystals 36
Figure 11: "Leopard granite" containing apatite
crystals
36
Figure 12: "Leopard granite" and pegmatite in
pyroxenite 36
Figure 12A:Apatite lens in pyroxenite
39
Figure 13: Mine entry, High Rock property 58 Figure 14: Underground workings, High Rock property 58 Figure 15: Picking belt, High Rock property 58 Figure 16: "Large dump", HiRh Rock property
60
Figure 17: Pit Number
77,
Bit Union property 65 Figure 18: Dump, pit77,
Big Union property 65scene of mining activity for over 60 years, is located in
the eastern part of West Portland township. The area surveyed is about three-quarters of a mile wide and 3 miles long s and includes roughly the southern two-thirds of the belt. It is from one-half to one and a half miles west of the Lièvre river, embracing lots in ranges VII, VIII end IX of this township.
The area is conveniently located within a couple of miles of a provincial highway (Route 35), some 20 miles north of the town of Buckingham. The nearest rail transportation is at Masson (Buckingham Junction) two miles south of
Buckingham. During the period of active exploitation of the apatite deposits, the Lièvre river itself was an important artery of transportation between the mines and Buckingham, being used by scows in summer and by sleighs in winter.
It is possible to drive to the main workings of two of the properties, the High Rock and Little Union, in a car or truck. The main workings of the Big Union are accessible by a road which is passable for wagon or truck. It is too rough for an ordinary passenger car, and would not stand up to heavy truck traffic, as the road-bed is too soft. In the fall of 1941 a road was cleared and partially filled, con- necting the High Rock and Big Union, but work had to be suspended before it was completed.
Acknowledgment s
The writer wishes to express his appreciation of the interested and careful work of his assistants, Pierre Mauffette and Ahmet Cebeci. They performed most of the routine plane- table surveying and also assisted in the geologic mapping.
The writer wishes to acknowledge the generous co- operation of owners and operators of the properties visited in supplying information and in many other respects. In par- ticular he would like to express his indebtedness to
Messrs. M. Vinant and the Comte de Roussy de Sales of the Commercial Minerals Co., Limited, Mr. O.C. Coté and Mr. H.E.
Corbett of the Barry Lake Mining Co., Limited, Mr. Walker, Manager of Electric Reduction Co. of Canada, Limited,
Mr. Paul D'Aragon, M.E. of the École Polytechnique, Montreal, Mr. Urban Cameron of Buckingham and Mr. R. Bigelow of Glen Almond.
The writer is also under obligation to Dr. G.A. Young, Chief Geologist of the Geological Survey of Canada, for making accessible various unpublished notes, and to Dr. M.E. Wilson of the Survey for information from his wide knowledge of the area.
Thanks are also due to Mr. Howells Frechette of the Industrial Minerals Milling Laboratory, Department of Mines,
Ottawa, and various members of his staff, in particular Mr. W.T. Turrall, for their friendly co-operation in arrang- ing for the assaying of samples from some of the dumps,
History and Development
Mention was first made of the presence of apatite in the Liévre river region by Lieut. Ingall in 18291 No 1. Spence, H.S., Phosphate in Canada; Mines Branch Report
No.396, 1920, p.15.
effort was made to develop these deposits until about 1875, some time after apatite mining had commenced in Ontario. Once under way, the industry developed rapidly, reaching a peak production of 27,552 tons in 1889. By this time small towns had grown up in the vicinity of the mines and an extensive system of wagon-roads and tramways had been developed to trans- port the apatite to the river. It is reported2 that the High 2. Small, H.B., The Phosphate Mines of Canada; Am. Inst. Min.
Eng., Transactions, 1892, p.774.
Rock mine employed "upwards of 200 men". This gives some in- dication of the scale of operations.
The apatite industry was thus just in its prime when the full effect of the large, easily-mined deposits of sedimentary phosphate in South Carolina and Florida began to show itself in greatly depressed prices. As a result, the mines closed down in quick succession after 1891, and by 1896 production had fallen off to a mere 570 tons.
Since that time a little apatite has been shipped out of the Liévre country nearly every year. Much of this comes as a by-product of the mining of mica, and the remainder
has come from the spasmodic efforts of lessors or owners to reopen the old workings.
Production of apatite for the Province of Quebec
1886 19,435 3288,603
1887 19,589 264,452
1888 20,396 219,779
1889 27,552 287,400
1890 27,172 309,980
1891 20,244 206,416
1892 10,231 134,964
1893 7,650 60,076
1894 6,861 41,166
1895 1,822 9,565
1896 570 3,420
1897 908 3,984
1898 632 3,160
1899 1,279 7,674
1900 1,270 6,090
1901 1,033 6,280
1902 856 4,953
1903 1,329 8,214
1904 817 4,590
1905 1,300 8,425
1906 600 4,500
1907 408 3,410
1908 598 5,900
1909 525 4,800
1910 1,456 12,386
1911 586 4,909
1912 164 1,640
1913 385 3,643
1914
5544,875
1915 200 2,400
1916 190 2,340
1917 123 1,230
1918 140 1,200
1919 22 300
1920 0 0
1921 30 450
1922 131 1,320
1923 30 600
1924 0 0
1925 16 189
1926 40 800
1927 31 399
1.928 91 1,126
1929
4080C
1930 40
1
7601931 0 0
1932 1,316 12,333
1933 105 805
1934 81 683
1935 116 1,043
1936 525 4,927
1937 100 900
1938 208 1,886
1939 157 1,712
1940 358 4,039
Previous Geological Work
The apatite deposits of Quebec have been the subject of geological investigation and discussion for many years. It is not profitable here to catalogue all that has been written regarding the apatite. This has been done very completely by Spence. Suffice it to say that in the majority of cases the
1. Spence, H.S., op. cit., p.110.
conclusions have been based on visits to the various proper- ties. The first regional mapping was done by R.W. Ells2 who
2. Ells, R.W., Report on the geology of Argenteuil, Ottawa and part of Pontiac counties, Province of Quebec and por- tions of Carleton, Russell and Prescot counties, Province of Ontario, Geol. Survey of Canada Ann. Rept., N.S., Vol.
XII, part J.
mapped a large area of western 2uebec and eastern Ontario, on a scale of 4 miles to the inch. The only relatively detailed
map hitherto published which has included the Lièvre phosphate
publication No.1691, 1920.
report on Phosphate in Canada, the only new contribution to the subject with which the writer is acquainted has been a paper by K.K. Landes. 2
2. Landes, K.K.,"Origin of the Quebec Phlogopite-Apatite
Deposits", Am. Mineralogist, Vol.23, 1938, p.359.
Figure 1: Pit Number 1, Little Union property, showing hoist house, stiff-leg derrick and cobbing house.
MINING METHODS
Mining methods used in the winning of apatite have been generally of a simple type and have changed but little since the earliest days. Operations have been carried on in open pits for the most part and where underground work has
been performed, it has been simply by the adaptation of quarry procedure. Modern methods of mining, and exploration have not been applied,
In present practice, drilling is done dry with light hand-pluggers supplied with air from portable gasoline-driven compressors. Blasting is carried out with light charges of 401. dynamite. Rock is removed from the pit by means of a stiff-leg derrick (Fig.l), using an air or gasoline hoist.
Large blocks are hoisted one at a time, while smaller material is raised in a bucket. Underground procedure is much the same.
At the High Rock mine, the muck is moved by wheelbarrow to a mine-car which is operated by a gasoline hoist. Coarse lumps of apatite are removed by hand, and the fines are screened.
The screenings do not generally contain a sufficiently high percentage of phosphate to be acceptable at Buckingham, but they are sweetened with lump apatite. Transportation to Buckingham is by truck, at the reported rate of $1.25 per ton from the High Rock and Little Union properties.
Practice was much the same 50 years ago. Steam power was used for hoisting and for the compressors, the boilers being fired with wood cut in the vicinity. Drilling was performed with heavy drills, so that over-hand stoping
could not be carried out, and in mining the apatite the prac- tice was to attempt to get on top of e given pocket and work down into it. Preliminary cobbing was done in the pits,
waste, pure apatite and cobbing ore being hoisted separately.
The mixed material went to the cobbing house. The Little Union and High Rock properties were provided with tramways (1 1/8 and 1 3/4 miles long respectively) which extended from the main workings to wharves on the Lièvre river. The tracks have been long since removed, but the embankments for them are still recognizable. Ore cars were hoisted up the hill and then let down on the long slope to the river. Tramming from individual pits to the tramways and from the Big Union property to the river was done by wagons.
TECHNOLOGY
At the present time, all the apatite produced in the Lièvre river area is shipped to the plant of the Electric Reduction Company, Limited, at Buckingham. The apatite is employed here for the manufacture of native phosphorus and phosphorus compounds. The consumption of phosphate at this plant is reported to be at the rate of 3000 tons per month.
Phosphorus is prepared from phosphate by fusion with quartz sand and coke in an electric furnace. Carbonate associated with the phosphate increases the amount of silica used in the charge, consequently it is an undesirable impurity.
It was reportedly found to be troublesome to obtain acceptable
apatite rock from the Little Union property because of the presence of considerable calcite with the phosphate. Sul- phides such as pyrite and pyrrhotite are also undesirable, since the iron in them takes up some of the phosphorus during fusion, and the sulphur adulterates the phosphorus itself.
The writer was informed that shipments with more than 1/10 of 1/. sulphur are not accepted. In the past Electric Reduction
Company has been in the habit of refusing shipments of apatite with an excess of fines. The reason for this is that an excess of fines tends to clog the charge and prevent the free passage of gases through it. The writer understands that fines of satisfactory grade are now accepted and mixed with Florida pebble phosphate to give a suitable charge. This is important because the apatite, especially the sugar variety, is so
brittle and friable that it is impossible to avoid producing a large proportion of fine material in connection with mining.
It is important also if some method of milling and concen- trating, such as by flotation, is projected.
Apatite may of course be used in place of rock phosphate for any of the many uses to which the latter is put. After removal of the fluorine, by any of the several methods which have been developed, it may be used as a ferti- lizer. It might also be used instead of rock phosphate in the basic steel process. These represent additional possible markets for Canadian apatite, if it could be produced at a price which would compete with the cheap American product.
Under normal conditions, it is stated that Florida phosphate rock containing 75% tri-calcic phosphate is laid down in Buckingham at a price of about $10.00 per ton. Due to the increased shipping rates resulting from wartime con- ditions, the same grade of phosphate is now worth $17.50 per ton, laid down in Buckingham. Consequently, apatite rock containing
70,
tri-calcic phosphate currently commands a price of .20$ per unit, or $15.00 per ton.New Developments
Research in the technology of phosphates and the discovery of new uses have been proceeding at an accelerated pace during the last ten or fifteen years in the U.S.A., Russia and Germany. It is not profitable here to discuss in
detail the advances in utilization and processing of phos- phate as information on this subject is available in several recent publications
1. Roush, G.A., Mineral Industry (chapter on phosphate), McGraw-Hill, New York. Issued annually.
Martin, H.S. and Wilding, J., Phosphate Rock, Am. Inst.
Min. & Met. Eng., Industrial Minerals and Rocks,
1937,
P.543.Copson, R.L., Pole, G.R., and Baskervill, W.H., Develop- ment of Processes of Metaphosphate Production, Ind. & Eng.
Chem., Vol.34, p.24, 1942.
Easterwood, H.W., Recent developments in the Phosphate Field, Ind. & Eng. Chem., Vol.34, p.13, 1942.
Many other references could be cited.
bibliography on the various phases of dustry is contained in the chapter on
"Mineral Industry" cited above. This tains the most recent articles in al]
as patents, etc.
A very complete the phosphate in- Phosphate in
bibliography con- languages, as well
Of particular interest in connection with a discus- sion of future possibilities in the Quebec apatite region is the development of flotation methods of concentration of apatite and other phosphate materials. The apatite ore from the great Khibin deposit of Russia has been beneficiated by flotation for the last ten or twelve years. The ore is re- ported to occur in two grades, with 49% and 67% tri-calcic phosphate respectively. Some is shipped in the crude state, but the balance is raised to
8o%
tri-calcic phosphate by flo- tation. The chief impurity of the apatite in these deposits is nepheline, so that the problem of flotation should berelatively much simpler than would be the case for the Quebec apatite with its variability of mineral association. The
flotation reagents used are said to be peat tar and oleic acid.
1. Eigeles, M.A. and Fedorov, P.N., Studies of Collectors for the Flotation of Nonmetallics, Trans. All Union
Sei.
Res.Inst. Econ. Mineral., No.127, pp.36-47, 1938. Abstract in.
Chemical Abstracts, 1939.
Sladkov2 reports that the place of tar may be partially taken 2. Sladkov, A.S., The use of Liquid Soap for Flotation of Apa-
tite at the Kirov (Russia) Concentration Plant, Tsvptnye Metal, Abstract in Chemical Abstracts, 1941, No.285 .
by liquid soap, with resulting improved extraction of phosphate.
Commercially successful flotation of phosphate rock has been practised for the last ten years in Florida and Tennes- see, by the Phosphate Recovery Corporation. The material
floated consists of tailings from mechanical concentration of
the phosphate, and comprises for the most part fine-grained phosphate and quartz. At first the mill-feed assayed 8 to 12% tri-calcic phosphate and it was concentrated to between 70 and 72%. Subsequently, it was found possible to obtain concentrates averaging 74 to 76% tri-calcic phosphate from tailings running between 4 and 6%. The mill-feed is composed of rejects or "debriq" from a system of washing and screening which separates the high-grade pebble phosphate from the low- grade fines. It is consequently fine-grained, ranging mostly between minus 8 and plus 200 mesh. The old tailings ponds are mined by hydraulic methods and put through a complex flotation circuit which has been fully described by Martin The re- 1. Martin, H.S., Milling Methods and Costs at the No.2 Concen-
trator of the Phosphate Recovery Corporation, Am. Inst. Min.
Met.
Eng., Milling Methods, Trans. Vol.112, pp.466-485,1934.agents used are described in this paper as "a fatty acid, a collector and a small proportion of a strong frother". Reagent consumption is reported as less than 1 1/2 lb. per ton of feed, costing 0.012e. The total cost of operation is said to be
0.1322$ per short ton of mill-feed. The plant of the No.2 concentrator is stated by Martin to have cost nearly $200,000.
It has a capacity of 100 tons of feed per hour.
APATITE DEPOSITS OF THE WORLD
Apatite is a mineral of widespread occurrence,
being present as an accessory in most igneous and metamorphic rocks and to a less general extent in sediments (especially of the clayey or "sealed" typel). As deposits of possible
1. Milner, H.B., Sedimentary Petrography, 3rd Edition, Thomas Murby & Son, London, p.502.
economic value it is much more restricted in its occurrence, but it has been mined at one time or another in nearly all the continents. The only deposits which have in recent years con- stituted an important part of the phosphate production of the world are the Khibin apatites of the Khola peninsula, Russia.
Apatite in Russia
The Khibin apatite region is located about 180 km.
(some 112 miles) south of Murmansk, and 60 miles inside the
Arctic circle. The deposits are located in the Khibine massif, a sub-circular lopolith of coarse nepheline syenite cutting Archaean and Proterozoic rocks. The massif is some 1385 square kilometers in area and is made up of two components. The outer ring is composed of "Khibinite", a very coarse-grained nepheline syenite, while the central portion is made up of foyaite, which is likewise coarse nepheline syenite. Along the contact between these two rocks an arc-shaped mass of fine-grained nepheline syenite and urtite-ijolite (nepheline-aegirine rocks) has been injected. The apatite ore forms a sill-3_ike intrusive which
strikes northwest and dips northeast at an angle of about
30°.
The footwall is the nepheline-rich rock "urtite" while the hangingwall is nepheline syenite. The apatite outcrops on two treeless hills, Kukiswumtschorr and Juksporr, which are separated by the Loparski valley. Kukiswumtschorr is the scene of exploitation at the present time. The Juksporr apatite is very thick (300 metres) but it is a low grade in- jection of nepheline rock which is not minable. Some seven kilometers southeast of the present workings, similar deposits are exposed on the mountain known as Raswumtschorr. The
mineralized zone may thus be, as much as
7
kilometers long.On. Kukisvumschorr the mineralization is made up of two zones, an upper high-grade zone carrying an average of 67/. tri-calcic phosphate, said to be 50 to
60
meters thick and a lower low- grade zone averaging 16 to 49`4 tri-calcic phosphate, and reportedly 130 to 140 meters thick.Tyrrell states that the deposits are worked in five broad benches, and that they are moreover provided with 20 miles of underground galleries. He also reports that reserves amount to 2000 million tons. Phosphate production in the Kola peninsula in 1940 may have been as much as 2,600,000 metric tons.
1. Mineral Trade Notes, Vol.12, No.4, p.19, 1941.
References
Martin, H.S. and Wilding, J., op. cit.,
p.555.
Tyrrell, G.W., Apatite, Nepheline and Rare-Earth Mining in the Kola Peninsula, Nature, Vol.141, p.354, 1938.
International. Geological Congress, 1937, Northern Excursion, Kola Peninsula.
Stutzer, O., Die Wichtigsten Lagerstdtten der "Nicht-Erze", Band 4, Phosphat-Nitrat, p.69, 1932.
Khvostovsky, The Phosphate Deposits of the Kola Peninsula, Eng. and Min. Jnl., 1931.
Granigg, B.,, Die Apatitiagerstr[tten in den Tundren von Chibine, Zeitschrift praktische geologie, Vol.41, 1933, p.l.
Apatite in Norway
Apatite has been mined in Norway since 1854, but the total production has not been large. The apatite is found in relatively narrow fractures in an olivine gabbro, which has a diabasic texture. In the vicinity of the veins, the gabbro has been altered to a hornblende-scapolite rock. The mineral- ization of the veins is complex, including chlorapatite, rutile, ilmenite, pyrrhotite, enstatite, hornblende, biotite, scapo-
lite and many less common minerals. Apatite veins also occur in hornblende schists, other schists, and granite. Apatite- pegmatite deposits are also reported.
References Martin, H.S. and Wilding, J., op.
Stutzer, O., op. cit., p.58.
Beyschlag, F., Krusch, P. and Vogt, J.H.L., The Deposits of the Useful Mineral and Rocks, tr. by S.J. Truscott, Macmillan and Co., Ltd., London, 1914, p.452.
Apatite in Spain
The apatite deposits of Spain are not now of cit., p.554.
importance commercially. In Estremadure, fluorapatite-
quartz veins are found cutting granite. They are associated with phosphorite deposits which, like the former, are at- tributed to the mineralizing effects of the granite.
Apatite also occurs in concentrations in a Tertiary eruptive alkaline rock, described by Osann as "jumillite", at Jumilla, in southeast Spain. The apatite content ranges from
71. to 300.
References Stutzer, O., op. cit., p.74, 129.
Gallwitz, Die Apatitlagerstgtte von Jumilla im Süastlichen Spanien, Zeit. fUr Prakt. Geol., Vol.41,
p.175, 1933.
Apatite in South Africa
Apatite occurs in the Palabora district of the north- east Transvaal, in dark green, pyroxenic shonkinites, associ- ated with limestones. At Zoutpansberg it is found at the
contact between pegmatite and gneiss, and in Sekukuniland it occurs with limestone, enclosed in nepheline sy enite.
References Stutzer, O., op. cit., p.84.
Shand, S.J., The Granite Syenite Limestone Complex of Palabora, Eastern Transvaal, and the associated Apatite Deposits, Trans.
of the Geol.
Soc.
of S. Africa, Vol.34, 1931, pp.81-105.Jannich, E.P., The occurrence of phosphate in the Zoutpansberg District of the northern Transvaal, Trans. Geol.
Soc.
S.Africa, pp.109-135, 1927.Apatite in South America
In Brazil apatite is mined in the state of Sao Paulo, in the vicinity of Ipanema. It is associated with pyroxene, nepheline and magnetite.
In Chile, apatite is reported from the provinces of Atacama and Coquimbo. The apatite is associated with amphibo- lite and iron ores (magnetite and hematite). Dikes of amphi- bole peridotite and pyroxenite are in close relationship to the deposits. The deposits have been classified by Cristi as (1) amphibolites with apatite, (2) irregular bodies of magmatic
segregation, (3) veins of magmatic segregation, (4) hydrothermal veins, (5) impregnations.
References Stutzer, 0., op. cit., p.85.
Cristi, J.M., Informe sobre los yacimientos de apatita en las provincias de Atacama y Coquimbo, Boletin Minero, Sociedad Nacional de Mineria, Vol.47, p.105, 1931.
Apatite in Asia
In China, apatite is mined in Kiangsu Province, where it occurs as an impregnation of Precambrian limestone, in crys- talline schists which disconformably overlie the Archaean
gneisses.
In India, apatite and magnetite occur in schists and quartzites of the Dharwar schists.
References Stutzer, O., op. cit.,
p.86.
Liu, C.C., The Apatite deposit of Tung Hai Hsien, Bull.
No.4, 1922, Geol. Survey China.
Murray, E.F.Q., The Apatite-Magnetite Deposits of Dhalbhum, India, Min.. rag. (London), Vol.XXIV, p.211, 1921.
Fermo r, L.L., The Mineral Resoures of Bihar and Orissa, Geol.
Survey of India, Records, Vol.LIII, p.295, 1921.
Fluorapatite has been mined in South Australia, at Bimberri Hill. It occurs in little pegmatite veins, cutting Precambrian gneisses and schists.
References Stutzer, O., op. cit.,
p.86.
Geol. Survey of South Australia, Bull. No. 7.
TOPOGRAPHY
The apatite belt is located in the Laurentian High- land, and is characterized by rugged, rocky ridges of rather uniform elevation. The Li
è
vre river occupies a valley which threads between these ridges in a southerly direction. This valley is floored by post-glacial marine clays which also spreads into tributary valleys and flats between the hills.Typical of the rocky hills is the ridge which rises above the main adit at the High Rock property. The crest of this ridge is said to be about 600 feet above the river.
Throughout the map-area, bedrock is generally quite near the surface in these ridges, but it is extensively covered with a thin blanket of soil and vegetation. This fact, combined with the complex intermingling of the various geological units
mapped, renders the representation of the distribution of the latter in any given outcrop largely a matter of interpretation.
In most cases the geological boundaries indicated are interpol- ated between isolated exposures which generally constitute only a small percentage of the outcrop.
The area mapped is covered with rather thick bush, which is mostly second growth, chiefly poplar and birch. A fair stand of pine was timbered a year or two ago, just south of the unfinished road from the High Rock to the Big Union.
Balsam, spruce and cedar are also locally fairly abundant.
The writer was informed that during the period when the various properties were in full. operation, the ridges in their vicinity
were almost completely denuded of timber, to feed the boilers.
Rotted woodpiles cut for this purpose and never used may still be seen, as for instance on the Ross Mountain lots. Thus the
present second-growth is between 50 and 60 years old. Sap- lings up to several inches in diameter grow even on the old dumps.
Figure 2: Veinlets of blue-white quartz (cellular) in- tersecting fine-grained biotite gneiss.
GENERAL GEOLOGY
The rocks of the area are all Precambrian in age.
They include a complex series of schists, gneisses, quartz-
ites, pyroxenites and limestones which are classed as Grenville in age. They have subsequently been intruded by a coarse-
grained pegmatitic granite, with the associated development of injected and mixed gneisses in considerable abundance.
These rocks are all cut by diabase and trap dikes.
Grenville Rocks
In the area mapped the Grenville rocks are of great complexity. This complexity results from (1) original dif- ferences of composition, (2) the varying degree of injection and metamorphism due to the intrusion of pegmatite.
Limestone
Limestone does not outcrop in the area mapped, but it is exposed in some abundance to the west and north.
Biotite gneiss
The biotite gneiss is a light coloured, siliceous rock which exhibits a well-defined bedding. It has been
veined extensively by bluish quartz (Fig. 2), so much so that in many cases small exposures of the gneiss may have been mapped as quartzite. Consequently, in drawing up the map, small areas of quartzite more or less isolated in bands of gneiss have not been differentiated from the latter.
In thin section, the typical biotite gneiss is found to be relatively simple mineralogically, consisting of coarse interlocking grains of quartz with scattered flakes of brown
biotite and chlorite. Perthitic feldspar is also present in moderately coarse, anhedral grains. Sphene, carbonate, tremo- lite, apatite, zircon and pyrite may occur in small amounts as accessories. An inclusion of biotite gneiss in pegmatite, from an outcrop at the road, east of pit 74, Big Union prop- erty, was considerably more feldspathic, differing from the typical material in the presence of plagioclase and magnetite.
An unusual specimen of siliceous gneiss from the Brazeau property contained, in addition to dominant quartz, scattered grains of deep green pyroxene, scapolite, carbon- ate, zoisite, sphene, zircon, sericite, chlorite, checker- board albite and apatite.
Quartzite
The quartzite is a massive, coarse-grained siliceous rock which is frequently bluish when moist. It contains coarse,
scattered grains of ferromagnesians, including biotite, horn- blende and pyroxene, and, commonly, irregular grains and patches of cream-coloured feldspar. In thin section, the quartz forms interlocking sutured grains which appear to be partly rimmed and sprinkled with much finer grains of the same mineral. It shows the effects of considerable strain under crossed ni_cols and is characterized by the presence of minute needles
(presumably rutile). The feldspar is microcline and perthite,
Fis gure 3:
Pyroxenite interbedded with quartzite, High Roek property. Note traces of bedding in both the white quartzite and the grey pyroxenite.of description. The northern or No. 2 workings comprise an open cut, a shaft, and some level workings from it. The southern workings have so for proved economically more important than the No 2 and include the No 1, pit with its shaft and level workings, the number 3 pit to the west of No l., and No
4
shaft with its workings. Most of the ore won has come from the No. 1 pit.
Number
6
trench is south of and nearly on the strike of the ore in number 1 pit so that practically it must be considered with No 1.Southern workings
No. 1 pit.'
From local accounts the position of No. 1 pit was occupied by a hillock on which the molybdenite-bearing rock cropped out. The upstanding mass was quarried and a pit was formed. The pit was quarried to greater and greater depth, and the broken rock was hoisted to the sorting tables in flat"skips" raised by steam engines operating cranes. Considerable sorting and cobbing were done. A visitor's first impression is that relatively little waste was discarded, but most of it was disposed of by dumping from wagons.
Northeast of the pit an area of approximately four acres is covered by the low heaps of waste dumped form wagons. These dumps are partly hidden by
young trees. However, the material dumped amounts to a considerable tonnage, and considering the size of the pit probably a third of the material removed was waste. The significance to be attached to these observations is that, with losses in the mill during the early period of operation, the present re- covery per ton of ore broken is probably not far different from that in the heyday of the property.
By the end of 1916 when 129,000 pounds of molybdenite had been mined, the pit was 115 feet long, 60 feet wide, and two thirds had been excavated to 50 feet.
Q.B.M.
Ann. Rept. 1916, p. 41x
FIGURE 3: No 1 pit.
Looking north chute raises from bottom right.
Fi ure 4: quartzite (white) and gneiss cut by pegmatite form ng the top quarter of the photographs).
in irregular grains. Sphene and biotite are also present in the section which was examined microscopically.
The origin of the quartzite is not always clear.
The quartz pit (number 3) on the High Rock-Little Union boun- dary contains occasional large crystals of feldspar and is
probably of pegmatitic origin. As already mentioned, siliceous veinlets commonly intersect the biotite gneisses. No essential differences, apart from coarseness of grain, have been noticed between this vein quartz and the quartz of the enclosing gneiss.
Thus the veins may be of either pegmatitic or metamorphic origin.
The quartz of many of the pegmatites in the area is bluish in colour like that of the quartzites and gneisses. On the other hand, narrow bands of quartz were noted, on the High Rock hill, south of pits 27, 29, etc., which are interbedded with pyrox- enite and gneiss (Fig.3). Just to the west of this locality, a mass of quartz was observed which is intruded by a pegmatite dike (Fig.4). The two occurrences must surely be true quartz- ites, i.e. metamorphosed siliceous sediments.
It therefore seems reasonably certain that quartz of both sedimentary (metamorphic) and igneous origin is present.
It is possible to distinguish the two only in individual cases such as the two just mentioned. The presence or absence of the blue colour and of scattered grains of feldspar does not seem to be significant.
Dark-coloured gneisses
The dark-coloured gneisses, schiste and amphibolites are prominent, although probably subordinate in amount to the
Figure
5:
Pyroxenite (rough, irregular surface) in con- tact with amphibolite (smooth surface, lower left hand corner of photograph).biotite gneisses and injected gneisses of the area examined.
Perhaps the most typical are brown to black, medium- grained, massive rocks. In thin section they are found to be composed of hypersthene, clinopyroxene, hornblende and biotite, with poorly twinned plagioclase which is usually labradorite. Mineralogically, therefore, these rocks would appear to be norites or hypersthene gabbros. The intimate association with other gneisses, the absence of any intrusive contacts (as far as can be told from available exposures), and the passage of some rocks of this type into pyroxenite on strike (Fig.5), are advanced as evidence for considering these rocks as metamorphosed sediments.
Accessory minerals in these rocks include apatite, zircon, magnetite, pyrite. quartz was noticed in one speci- men, but is generally absent. In some thin sections the plagioclase was found to be sodic andesine rather than lab- radorite. Also, in some cases, the feldspar has been more or less altered to sericite or scapolite. Alkali feldspar or perthite also was noted in a few thin sections.
Another group of these dark gneisses differs only in the absence of hypersthene. The clinopyroxene varies from the dominant ferromagnesian to mere remnants included in the hornblende. Plagioclase, which is the most abundant light- coloured mineral, is variable in composition, from sodic andesine to labradorite and may be accompanied by alkali feldspar (orthoclase or perthite). Again quartz was only observed in one section.
Texturally these rocks are generally mosaics of more or less equidimensional feldspar grains with subhedral pyroxene and hornblende. In the hand specimen, they exhibit a variety of habits, depending on the relative proportions of the various minerals. Generally the biotite forms more or less continuous sheets around the amphiboles and pyroxenes, so that the rock often has the appearance of being predom-
inantly biotitic. The development of broad flakes of biotite, or the predominance of feldspar, with a noticeable gneissic structure, confers a blotchy appearance on the rock. A pre- dominance of feldspar, with a massive habit, results in a
rock which is dioritic in appearance. This aspect is enhanced if the dominant ferromagnesian is hornblende. Where the rock is predominantly dark or black, with evenly distributed white feldspars sprinkled through it, as shown by some amphibolites, it is termed "pepper-and-salt" amphibolite. Where possible, these various types have been indicated on the map.
Injected and pegmatitic gneisses
All the gneisses of the area have been injected by pegmatite and quartz to a greater or less degree. Many, how- ever, show evidence of actual impregnation of the original rock by quartz and feldspar (i.e. pegmatitic material), until these constitute a more or less dominant part of the rock, and the inherited structure and the scant fer.romagnesians are the only relics of its former character. .^-_ll gradations may be found between the uninjected, normal gneiss and its completely
.111111 , F_
Figure
6:
Sillimanite-garnet gneiss, injected by pegmatite.Figure 7: Sillimanite garnet gneiss (same outcrop as Figure 6) illustrating blotches of feldspar and irregu- lar injections of pegmatite,
"pegmatitized" equivalent. In general it may be said that the latter is characterized by the abundance of quartz and feldspar (generally orthoclase), the coarse texture, with a
strongly pegmatitic appearance, and the generally complicated, crenulated drag-folded and "fluid" structure (see Fig. 6,7).
Garnet and sillimanite are often found in these gneisses, and are not known to be present in the uninjected, ungranitized rocks.
About 800 feet east of pit 39, along the road right- of-way, an outcrop of injected gneiss is well exposed in a shallow trench cut for drainage purposes. On the fresh sur- face it is predominantly pegmatitic, but when weathered is decidedly gneissic in appearance. The gneissic structure is emphasized by the distribution of biotite and large red gar- nets. In thin section, quartz in coarse sutured grains is by far the most abundant mineral. Orthoclase, perthite, myrmekite, tattered biotite and subhedral garnet make up the rest of the rock, along with zircon and sphene. Gneisses to the east, overlooking the swamp south of the High Rock property are
similar in composition. Associated with these garnet gneisses are similar rocks containing sillimanite, with or without
garnet. A specimen containing sillimanite alone was examined microscopically and was found to contain abundant quartz, ir- regular poikiloblastic grains of plagioclase, interstitial alkali feldspar, brown biotite, sillimanite, associated with biotite and muscovite, and accessory apatite, zircon and magnetite. A specimen of sillimanite-garnet gneiss differs
Figure 8: Gneissic pyroxenite, pit 52, High Rock Property.
This structure is believed to be a result of injection.
Note the strong development of horizontal joints, and one south-dipping joint. The light coloured rock in the center of the picture is pegmatite.
from the preceding in the absence of plagioclase and in the predominance of augen-like grains of orthoclase. The quartz has a granulated appearance. Sillimanite-garnet gneiss from the Brazeau property is very similar, but does not show granulated texture. A well-exposed outcrop, il- lustrated in figures 6 and 7, located just west of pit 40, on the High Rock property, is composed of sillimanite. It is made up of equal quantities of quartz and perthitic ortho- clase, with coarse, abundant
accessory tourmaline, rutile Somewhat different bodies are injected gneissic well exposed underground at and 52 on the same property patchy, blotched or streaky is present in small pockets abundant. In thin section,
sillimanite, biotite, garnet and and zircon.
from these siliceous injected
pyroxenites. These are especially the High Rock, and in pits 31, 50 (see Fig.8). These rocks are
green and white gneisses. Apatite and sphene may be exceptionally
clino- the prominent minerals are
pyroxene, epidote and saussuritic material, carbonate, alkali feldspar, sericite and pyrite, in addition to the two minerals previously mentioned.
Pyroxenite
The pyroxenite is variable in colour, texture and mineral association. The most ubiquitous minerals are clino- pyroxene, phlogopite and apatite. Scapolite is a very common constituent, but in many cases it has been more or less
altered to a micaceous aggregate which probably corresponds
to "Wilsonite". The typical pink colour of this mineral was not observed in any of the exposures examined, however.
Plagioclase, largely altered to sericite or scapolite is an important constituent in a few instances. Pyrite, pyrrho-
tite, sphene and carbonate are widespread, but are not usually abundant, except in the case of the last mentioned, which is present in considerable bodies at the Little Union and Ross Mountain workings. Hornblende is found as an alteration pro- duct of pyroxene, but is rarely prominent. It also forms euhedral crystals in calcite veins and patches included in the pyroxenite. Tremolite is a minor constituent in some altered and injected pyroxenites. Epidote and zoisite, as well-formed crystals or indefinite saussuritic masses, were observed in the same association as tremolite, and are
especially characteristic of gneissic, injected pyroxenites found in the underground workings of the High Rock property.
Prehnite occurs in the same association. Quartz is found as introduced, interstitial grains. Alkali feldspars (predom- inantly orthoclase) form varying proportions of injected or partially pegmatitized pyroxenites.
The texture of the pyroxenite is by no means uniform.
In typical exposures in pit 74, Big Union property, the pyrex- enite is coarse but variable in grain, and contains scattered coarse flakes of phlogopite, and pockets and individual crys- tals of apatite. On the Brazeau property, black pyroxenes up to several inches in diameter are displayed on the walls of the main pit, with apatite. Coarse pyroxenes are also found
on the Little Union, Ross Mountain, and to a minor extent, High Rock, associated with bodies of carbonate in the pyrox-
enite. In the average pyroxenite, however, the pyroxene ranges from less than one to five millimeters in length. In
some cases the pyroxene is the sole constituent, with none of the other minerals mentioned associated. The rock is then commonly made up of uniform grains, of size generally near the lower limit of the range mentioned, and exceedingly compact, tough and hard. It is shiny black to dove grey or greenish grey in colour, and is reputed, by some of the operators, to be "dry" or unfavourable for the occurrence of apatite. The supposedly more productive type is softer, looser in texture and more easily drilled. A not-uncommon texture in the pyrox- enites which contain significant amounts of scanolite is a poikilitic distribution of the
of scapolite. Although enclosing pyroxene, its the diameter of the associated looking variety of pyroxenite,
pyroxene in large glistening mica rarely forms poikilitic flakes are usually several times pyroxene. An unusual gneissic- encountered in test-pits east of plates
plates
the truck road, on the High Rock property, consists of predom- inant scapolite, with considerable pyroxene and abundant pyrite.
Just east of pit
33
(High Rock) and on the dump of pit 1, Little Union, pyroxenite was observed which consists of alternating layers of pyroxenate and apatite, the layers being about 1/10 inch in width. This structure is illustrated byFigure 9: Sketch showing fractured pyroxenite, with later apatite, from the High Rock dump.
Figure 9A: Sketch, illustrating interbanding of apatite and pyroxenite•
Harrington. 1 Detailed relationships between the apatite and
1. Harrington, B.J. , Report of Progress, Geol. Survey of Canada, 1877-78, p•9G•
pyroxene indicate that the structure is a result not of frac- turing, but of intimate intergrowth, with perhaps some replace- ment. A specimen from the High Rock dump, however, indicates that in some cases the pyroxenite was fractured or brecciated before the apatite crystallized (see sketch, Fig.9!.
No definite example of the intrusion of pyroxenite into any of the associated rocks was encountered in mapping.
When in contact with quartzite or gneiss, the contact is generally parallel to the strike of the gneiss. As already described, it has been found interbedded with these rocks on the crest of the High Rock hill, and in some pits, e.g. pit 31, banded gneisses occur within the pyroxenite body, again paral- lelling the general strike at that point. As pointed out on an earlier page, in one or two places the pyroxenite apparently grades into dark amphibolite-pyroxene gneisses. Finally, the pyroxenite appears to have been intruded by pegmatite in every case where the two are in contact. With respect to its re- lationship to carbonate, in pit 93 on the Ross Mountain property, there appears to be a gradation between the pyrox- enite on one hand and the calcite on the other.
Origin of the Pyroxeni.te
Two contrasting theories of the origin of the nyrox- enite have been advocated by the geologists who have studied
the apatite deposits. The one theory, sponsored by Eugene Coste, R.A. Penrose, A.R. Selwyn, R.W. Ells, A. Osann and more recently, by H.S. Spence and K.K. Landes, classes the 1. Coste, E., Phosphate Deposits in the Archaean Rocks of
Canada", Geol. Survey Canada, Ann. Rept., N.S. III, 1887-8, 625.
Penrose, R., Nature and Origin of Deposits of Phosphate of Lime, U.S.G.S. Bull. No.46, 1888, pp.23-42.
Selwyn, A.R., Geol. Survey Canada, Ann. Rept., N.S., Vol.
VI, 1892-3, .p.40AA.
Ells, R.W., Rept. on Geology of Ottawa and Pontiac
counties in Quebec, Geol. Survey Canada Ann. Rept., N.S., XII, 1899, part J.; also part G, p.41, XIV, 1901, part J.
Osann, A., Archaean Rocks of the Ottawa Valley, Geol.
Survey Canada Ann. Rept., N.S. XII, 1899, pp.19-27 0.
Spence, H.S., op.cit., pp.110-117.
Landes, K.K., op. cit., pp.362, 384, 385.
pyroxenite as a normal basic igneous rock. The other, proposed by some of the earliest workers, and most effectively presented by N.E. Wilson and M.B. Baker, considers it to be metamorphosed 2. Wilson, N.E. , Southwestern Portion of the Buckingham Map
Area, Quebec, Geol. Survey Canada, Sum. Rept., 1915, pp.159 and 161.
Baker, M.B., The Geology of Kingston and Vicinity, Ont.
Bur. Mines, Ann. Rept., Vol.25, part 3, pp. 29, 30.
sediment, specifically, in the case of the two last mentioned, a contact-metamorphosed calcareous sediment. Wilson distin- guishes "pyroxenites" of this origin as "metamorphic pyroxen- ites". Adams and Barlow3 have also described the origin of 3. Adams, F.D. and Barlow, A.E., Geology of the Haliburton
and Bancroft Areas, Province of Ontario, Geol. Survey
Canada, Mem. 6, 1910, pp. 87-93.
pyroxenites by contact metamorphism of limestones, but have not applied it to the rocks in the area under discussion.
The evidence obtained during the current work has tended to corroborate the views of Wilson and Baker. The following points are presented in support of the contact metamorphic origin of the pyroxenite:
(1) The presence of unreplaced carbonate in some pyrox- enite zones (e.g. Ross fountain) and the occurrence of lime- stone bands containing disseminated pyroxene crystals
(Brazeau property).
(2) The frequent abundance of scapolite, sphene, phlogo- pite and tremolite, which are characteristic of contact
metamorphic zones.
(3) The extreme variability of grain shown by the pyrox- enite, even in a single small pit, with the development of very coarse crystals in some places, is more typical of metamorphic than igneous origin.
(4) The general parallelism of the pyroxenites with the structure of the enclosing rock, and the interbedding with quartzite and gneiss has already been described and is of primary significance.
(5) One of the underlying reasons for the interpretation of the pyroxenites as igneous intrusions is the analogy with the scapolitized gabbro associated with the apatite deposits of Norway. This analogy is more apparent than real, for the scapolite in the pyroxenites of the Lievre area is clearly
derived from plagioclase (as in the case of the Norwegian rocks) in only a relatively small proportion of the cases.
On the contrary it commonly forms fairly coarse clear plates, sometimes as already noted, with poi.kilitic inclusions of pyroxene, a texture which can scarcely have been produced by the replacement of plagioclase.
(6) No evidence of intrusive relations of the pyroxenite to associated rocks could be established. It has been stated by Spence that the "pyroxenite exhibits sharp frozen contacts with the enclosing gneiss or limestone". In the area mapped the writer was unable to find evidence substantiating this statement.
The principal basis on which the igneous origin of the pyroxenites is founded, apart from the anlogy with the Norwegian deposits already mentioned, is the supposed cross- cutting relationships of the intrusive. Reference to these relationships is made by Landes1 and :Spence? As indicated 1. Landes, K.K., op. cit., p.385.
2. Spence, H.S., op. cit., p.115.
in points 4 and 6 above, the writer is unable to agree with this statement. The general parallelism of the pyroxenites with the local strike of the gneisses and quartzites is readily apparent on reference to the accompanying map, and is also obvious in many parts of the Buckingham sheet
3. Wilson, M.E. , Buckingham Sheet, Geol. Survey Canada, publication No.1691, 1920.
Tt is, however, not impossible that intrusive relations may locally prevail, since the Grenville marbles have long been known1 to intersect adjacent formations, due to the flowage 1. Hunt, T.S., Geol. Survey Canada, Rept. of Progress,
1863-66, p,182, and numerous references since that time.
resulting from folding.
Pegmatite, Granite z etc.
Pegmatite is quantitatively one of the most abun- dant rocks and there are few outcrops in which it does not occur. It is variable in colour and texture. Pink, red, purplish, black and white pegmatites are all common. The small amount of microscopic work so far done on these rocks has failed to indicate any essential mineralogical differences between these various hues. The quartz of the rock frequently has a pronounced bluish cast, although it i just as frequently clear or milky and granulated.
The typical pegmatite is coarse-grained. Rarely it has a normal granitic texture, and arli.tic phases also occur.
Some occurrences of the pegms ti.te are massive, clear and well- defined. Examples are just southeast of the Caprock pit
(number 46), east of the Donovan pit (number 39) and along the north side of the Dugway road. In the majority of outcrops, however, the pegmatite contains inclusions of pyroxenite and.
gneisses, and traes of the structure of pre-existent rocks.
From these it passes by gradations into mixed and injected
gneisses. The existence of these transitional rocks makes the classification of an outcrop as between pegmatite and gneiss an extremely difficult one.
A striking textural characteristic, which is rather frequently observed in the field is the subhedral to euhedral habit of the feldspars, which are embedded in a quartz matrix of variable grain. At times the quartz may greatly exceed the feldspar in amount, so that the pegmatite is a quartz body with scattered crystals and groups of feldspar. As al- ready noted, the quartz of pit number 3 is of this type.
Pegmatite from the underground workings of the High Rock,
which shows this texture, is especially noteworthy because the feldspars are quite black while the enveloping quartz is granu- lar and white. In some pegmatites, the feldspar and hornblende have been fractured and are veined by the quartz. A few out- crops of pegmatite appear to have been completely granulated, giving an aplitic-looking rock in which the f erromagnesians have been drawn out into elongated spindles. This sort was encountered in a few small outcrops south of pit number 124.
A variety of pegmatite which has been frequently re- ferred to and illustrated in the literature is known as
"leopard granite", and is found exclusively in the vicinity of pyroxenite-apatite deposits. It is a medium to fine grained pegmatite which on a flat surface is seen to be marked off into elliptical areas by chains of dark pyroxene crystals. All sides of a given block show the same pattern, clearly indicating that
Figure 10: "Leopard apatite. Just above from whi ch a crystal surfaces , also shown
granite" containing crystals of the head of the hemmer is a cavity has been removed. Note the rounded by the crystals still in place.
Figure 11: "Leopard granite; containing apatite crystals ani inclusions of pyroxenite, underground at the High Rock property.
Figure 12: "Leopard granite" and pegmatite (white), intruding pyroxer_ite (dark grey) with apatite (light grey). Vote horizontal joint.
these chains are actually continuous ovoid shells enclosing ovoidal masses of the rock. Nonetheless, the rock shows no disposition to separate along these shells, but breaks as if it were homogeneous. These structures have been described erroneously as tiny fractures or tension cracks which have been injected by the pyroxene. Obviously no system of frac- turing could possible produce such ovoical patterns. Moreover, the pyroxene crystals which make up these net-like shells are intergrown with the feldspar of the "granite" in such a way as to preclude the possibility of their being vein fillings. In one or two cases, the pegmatite actually appears to be somewhat finer-grained at the boundary of these ovoidal masses, and
coarser at the centre.
Apatite frequently is found enclosed in the "leopard granite" in crystals of considerable size (see figures 10, 11), These crystals are corroded, are commonly enclosed in rims of pyroxene, and appear in some cases to be cut by narrow strin- gers of the "granite".
It can be definitely stated that this structure does not result from fracturing and veining by pyroxene, but no a1r ternative explanation can be offered. In a broad way it may be said that the structure appears to result from the injection of pyroxenite or perhaps carbonate rook by pegmatitic material.
The injected rock appears to have contained apatite previous to the intrusion. "Leopard granite" is also known from the apatite region of Ontario.
In thin section, the commoner pegmatites of the area contain orthoclase or microcline as their dominant feld-
spar. They are frequently perthitic. Some albite or more calcic plagioclase is often present. The ferromagnesians include hornblende, pyroxene and biotite, and in the contam- inated, mixed pegmatites, garnet is a frequent constituent.
In the sheared and altered pegmatites, epidote and chlorite are found in place of the more normal dark minerais. The accessories include apatite, sphene, zircon, iron oxide, pyrrhotite and pyrite.
In thin section the "leopard granite" is found to consist chiefly of microcline, in part perthitic, with or without quartz. In the former case, rricropegmatite may be formed. The rims, as already indicated, are chiefly composed of a green pyroxene which Landes1 states is augite. With it 1. Landes, op. cit., p.377
are associated some tremolite, hornblende and sphene. Car- bonate may be present, but is often separated from the feld- spar and quartz by rims of hornblende or pyroxene.
Pyrrhotite is locally quite abundant in outcrops of pegmatite, forming prominent "burns". Several pods of more or less massive pyrrhotite have been uncovered in the quartz pit (number 3).
The pegmatite intrusions do not fall into any clearly defined pattern. Most of the intrusions and bodies are roughly parallel to the structure of the enclosing gneisses but many
s
roughly dike-like masses were observed, cutting more or less at right angles to the northwest-southeast trend of the
gneisses. Many dikes, too small to indicate on the map, were encountered with this trend. Of special interest are irregular bodies of varying size in the pyroxenites (Fig. 12), They may branch and ramify through the latter, or form isolated patches, or even fairly regular narrow dikes. They appear to cut
through pyroxene and apatite alike.
Apatite Deposits
The apatite deposits may be classified into several groups. In the area examined the following were recognized:
(1) Pockets and lenses in pyroxenite; also narrow seams and stringers.
(2) Vein-like masses with mica.
(3) Apatite uniformly distributed through massive
pyroxenite-scapolite rock ("dioritic pyroxenite").
(4) Crystals in vein-like bodies of calcite.
(5) Crystals disseminated through "leopard granite".
The first and fourth are the only ones which have yielded an important amount of apatite. The first is by far the most common and may be observed in pits on all of the properties described. The apatite bodies of this type are exceedingly variable in size, shape and attitude. The largest one exposed in any of the accessible workings, during the
writer's stay in the area, was observed in the main pit of the Brazeau property. A single pocket in the southwest face of the pit is 8 feet thick and at least 15 feet wide, and
Figure 12A: Gently dipping apatite lens in ,pyroxenite, pit 50, High Rock.
immediately below it is another with a maximum thickness of
6
feet. Much greater widths are reported to have been worked in the past. Thus Soencel states that the underground work- ings at the High Rock followed a "vein" of apatite which was 1. Spence, H.S., op. cit.,p.79.
30 feet wide. Ells2 reports "In some of the occurrences the 2. Ells, R.W., "Apatite': Mineral Resources of Canada, Geol.
Survey Canada, Publication No.881, 1904.
quantity of apatite was very large, exhibiting a chimney like structure, and where several of those were found, occurring along a fairly well defined course, the series were often connected by small stringers of the mineral, though this was by no means a universal feature." This type of deposit ranges from large bodies down to thin stringers and patches a fraction of an inch wide. As pointed out by Harrington3 3. Harrington, B.J., op. cit., p.9G.
years ago, the boundaries of these bodies are not usually
sharp. They grade into pyroxenite which contains disseminated grains of apatite and conversely around their edges the apatite masses are sprinkled with pyroxene grains. Some seams and
pockets, however, have relatively sharp contacts. As noted.
elsewhere in this report, some seams and lenses have a nearly horizontal attitude (Fig.12A).
The apatite in this first and most important type of deposit is of two varieties, massive and "sugar" apatite.
The massive apatite is found in several colours. Yost commonly it is green or greenish blue, but yellowish green, greyish
green, blue, brown, red and smoky grey are frequently encoun- tered. Red apatite from the High Rock mine is very compact and massive, and seems harder and tougher than the normal
variety. It is prominently veined and impregnated by fine- grained pyrite. Weathered apatite of this class of deposits is yellowish white or white in colour.
The "sugar apatite" is generally pale green to green- ish white and is characterized by its very granular, incoherent nature so that it can be crumbled to sand in the fingers. In some cases it is found along shear zones where it appears to have resulted from shearing of the more massive material. Thin sections of this granular apatite have failed to reveal unequi- vocal evidence of cataclastic processes. "Sugar" apatite from the High Rock workings in some cases contains phenocrysts of corroded reddish apatite enclosed in a granular matrix, which may contain an unusual amount of fine pyrite.
A rather significant feature of the bodies of apatite in pvroxenite is the intersection of both pyroxene end apatite by stringers and dikelets of pegmatite. This corroborates the relationship inferred for the "leopard granite". SAencel has 1.. Spence, H.S., ivrica, Publication No.701, Mines Branch, Can.
Dept. of Mines, p.40.
also referred to the deformation of mica and apatite by the injection of pegmatite.
Veins or vein-like deposits containing apatite and phlogopite are exposed in pit 134 and in a small pit just northwest of pit 81. Vein-like bodies of apatite filling joints were also observed at pits 106 and
37
on the High Rock property. These veins are not important as a source of mica or apatite in the area examined and should probably be con- sidered only a special case of the first type.The third type of occurrence, evenly disseminated apatite, is especially well-developed on the brow of the High Rock hill, southeast of pit 50 and south of pit 23. This zone is perhaps 20 feet wide and between 300 and 400 feet long. No sampling was attempted, but it is probable that the apatite content does not much exceed. 10% of the rock. Similar dis- seminated apatite outcrops about 1500 feet west of pit
77.
The pyroxenite in these occurrences is massive, coarse, dior- itic in•appearance, and is composed mainly of pyroxenite and scapolite, with apatite.
In the High Rock underground workings and in the east end of pit 31, corroded crystals of apatite, some over a foot in diameter, are found enclosed in "leopard granite". The re- lations of the apatite and the "leopard granite" have been discussed on an earlier page.
Apatite-mica deposits in carbonate have their best development, in the area examined, at the Little Union property (nit 1). The apatite in this variety is found in euhedral
green crystals with rounded edges. Mica, pyroxene and horn- blende occurring with the carbonate also are well crystallized,
In the field and in thin section, the carbonate shows evidence of replacing the other minerals, but it seems difficult to imagine the mode of formation of these crystals, where they occur entirely isolated in the carbonate, if we do not assume the pre-existence of the carbonate. This relationship, in which minerals developing from the carbonate are themselves replaced by it, is frequently shown by contact metamorphic rocks.
The carbonate of these deposits is creamy to pink calcite. It is in the form of coarsely cleavable masses, often with curved cleavage surfaces. It not only occurs in veins and large bodies but also in small patches, pockets and interstitial grains in pyroxenite. Narrow stringers were also noted in the High Rock mine, cutting impartially through pyroxenite, pegma- tite and apatite. Tiny crystals of apatite were observed in one of these veins.
The pyroxene associated with these calcite bodies are black in colour and unusually well-formed. They are found
chiefly at or near the edges of the carbonate. They appear to grade fairly rapidly into normal pyroxenite. Landes' states 1. Landes, K.K., op. cit., p.369.
that the pyroxene is diopside, but that it is younger than the pyroxene of the pyroxenite. Tremolitic amphibole has been observed with the same relations as the pyroxene.
Veining relationships such es reported by Landes, as between the diopside of the pyroxenite and the younger
diopside were not encountered by the writer. On the contrary, the coarse black crystals projecting into the carbonate ap- peared to grade into the finer-grained, greener pyroxene of the enclosing rock.
Sulphides occur in considerable abundance with the apatite-carbonate bodies. They include pyrite and pyrrhotite and are frequently found enclosing the apatite. Locally,
small vugs are found in the carbonate. Some contain coatings of crystals of quartz, carbonate and colourless to blue fluor- ite. A second generation of calcite was observed in material on the Little Union dump. It is white and occupies joints in the pyroxenite. Where the veins pass into the coloured calcite, they cease to be recognizable. In some cases the carbonate has been leached from these bodies leaving small caves lined with apatite and pyroxene crystals. Two of these were encountered on the Ross Mountain property.
Cri_nin of the apatite dejosits
A historical review of the various theories which have been advanced to account for the origin of the apatite deposits of Ontario and Quebec has been given by Spence, Osann, Ells; and others. It would be superfluous to repeat 1. Spence, H.S., op. cit., pp.110-115.
Osann, A., op. cit., pp. 12-17.
Ells, R.W. , op. cit., pp. 8-10.
them here. The concept that these deposits represent sedi- mentary phosphates, or metamorphosed and redistributed
sedimentary phosphates, has not been seriously entertained for many years. There seems little doubt that the apatite is of epigenetic origin, introduced from an igneous source. The fundamental differences in the recent theories are concerned more with the genesis of the pvroxenites than with that of the associated apatite.
Spencel has expressed the opinion that the apatite 1. Spence, H.S., Mica, Mines Br. publication No.701, Can,
Dept. Mines, n.42.
and mica deposits were formed from the pegmatitic residues of the pyroxenites which, as already noted, he regards as of igneous origin. Earlier he had expressed the opinion that 2. Spence, H.S., Phosphate in Canada, Mines Br. publication
No.396, Dept. Mines, Canada, p.122.
the pegmatites which intrude the pyroxenites were responsible for the mineralization. Landes3 has stated that the apatite 3. Landes, K.K., op. cit., p. 388 et seq.
was introduced as a hydrothermal phase of a pegmatitic magma which had become contaminated by contact at depth with mag- nesian limestone. A much simpler viewpoint is advocated by M.E. Wilson who ascribes the apatite and mica deposits, and 4. Wilson, M.E., Southwestern portion of the Buckingham map
area, Quebec, Geol. Survey Canada, Sum. Rept.,1915, pp. 159 and 161.
the associated pyroxenites, to a contact metamorphic origin.
This theory is also advanced by M.B. Baker, on the basis of
