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By Deborah McCombe

"and Bill Roscoe, Consulting Geologist and Principal with Scott Wilson Roscoe Postle AssociatesMineral property valuations are carried out for a variety of reasons, such as mergers and acquisitions, non-arm’s length transactions, initial public offerings of stocks, support of audited financial statements, fairness opinions, determination of vendor considerations, litigation, expropriation, income tax matters and insurance claims.The CIMVal Committee was formed in 1999 to review and advise on approaches to the valuation of mineral properties. CIMVal is a special committee of CIM formed on the recommendation of the Mining Standards Task Force of the Toronto Stock Exchange and the Ontario Securities Commission.After solicitation of views and consultation with various interested parties, the CIMVal Draft Standards and Guidelines for Valuation of Mineral Properties were released for comment in February 2002 and were finalized in February 2003. CIMVal’s objective was for the standards to be used by the mining industry in general and to be adopted by Canadian securities regulators and Canadian stock exchanges. To that end, the standards contain many of the definitions and concepts of National Instrument 43-101, Standards of Disclosure for Mineral Projects, which came into force in February 2001.The intent of the CIMVal Standards and Guidelines is that mineral property valuations be carried out by appropriately qualified individuals and that all relevant information be fully disclosed. It consists of two parts: standards, which are mandatory in the valuation of mineral properties, and guidelines, which elaborate on the standards and provide guidance and recommendations for the valuation process and for reporting."

Jan 1, 2003

By S. L. Gertsman

Canadian steel foundry practice has made marked progress during the past decade. Equipment suppliers, development engineers, and foundry personnel have focussed their attention on every phase of the foundry operation, with a resulting lower demand on manpower and materials. Also, more rigid specification requirements as to dimensional tolerances and quality have necessitated improvement and increased control at every stage from the pattern shop to the cleaning room. The growing trend toward mechanization is clearly evident. Equipment such as sand mixers, sand reclamation systems, material handling devices, moulding machines, core blowers, etc., is being increasingly employed by the steel foundryman. This equipment not only increases production but also tends to lessen the human variable so prevalent and disconcerting in the early days of steel founding. The result has been an improved and more reliable steel casting, which is gradually obtaining wider acceptance by design engineers. The purpose of this paper is to discuss briefly some of the practices being used, and also the direction of development that is being pursued by Canadian steel foundrymen.

Jan 1, 1948

By C. M. Bartley

Canada has been a producer of sulphur in various forms for about 100 years, Pyrites, as a source of sulphur dioxide for the manufacture of sulphuric acid, were being mined in the 1860's. Smelter gas, for the same purpose, has been recovered since 1928. Between 1935 and 1943, and from 1952 to the present, elemental sulphur has been produced in Canada from two raw material sources and by several methods. This paper attempts to present a view of the current status of the elemental sulphur industry in Canada based on the sour gas fields of Alberta and British Columbia. Production from this source has increased rapidly in the past 12 years to make Canada one of the major sulphur producers of the world. The present industry in Canada relies mainly on sour gas sulphur and it is expected that it will continue to grow in the future. However, before describing current activity relating to sour gas it may be of interest to outline briefly the early pyrite activities, the roots of the sulphur industry in Canada.

Jan 1, 1964

By G. A. Gordon

For the purpose of examining a specific problem, it is important that we look at the context, to obtain an appreciation of the general area of which the particular problem forms a part. It is my task today to speak on a particular relationship between the nations of Canada and the United States of America. What is the background? Almost two hundred years ago we both belonged to a family of nations -- the British Empire. There was a serious family quarrel in 1776 and the United States left the family and set out to make its own independent way in the world. Canada, which was not as grown up as the united States, remained with the mother country, and in 1812 resisted a vigorous attempt by the United States to get it to leave home too. With the passing of the years the bitterness of that family quarrel has faded and, aside from occasional differences, we have been getting along very well ever since.

Jan 1, 1962

By AIME AIME

A JOINT meeting of the Canadian Institute of Mining and Metallurgy and the American Institute of Mining and Metallurgical Engineers was held at Spokane, Wash., and Cranbrook and Kimberley, B. C., on Oct. 13 to 16, 1926, with a total attendance at one or another or all of the meetings of about 300 members, ladies and guests. At the opening meeting, on Oct. 13, in the Davenport Hotel, Spokane, about 175 were present. The morning was occupied with addresses of welcome by M. H. Sullivan for the Columbia Section, who called on Mayor Charles A. Fleming, President John F. Davies for the Chamber of Commerce, and E. R. Hannibal, president of the Associated Engineers, each of whom heartily welcomed the visitors. Philip N. Moore, former president, and special representative of President Samuel A. Taylor, replied for the A.I.M.E., and Lewis Stockett, president, and Charles A. Banks, chairman, British Columbia Division, Canadian Institute of Mining and Metallurgy, and Henry M. Parks for the visiting A.I.M.E. sections, made appropriate responses on behalf of those they represented. The members and ladies had luncheon with the Associated Engineers. Philip N. Moore addressed the assembly on "The Opportunity of the Engineer"; an excerpt from his address appears on another page. At the afternoon meeting, with Lewis Stockett in the chair, Frank M. Smith was asked to make a brief statement of the proceedings of the Silver Producers Association in Denver. Supplementing his talk by placing a well-prepared statement on "Silver and the Plan of the Royal Commission on Indian Currency and Finance" in the hands of those present, he narrated what had been undertaken by the Silver Producers Association and what they hoped to accomplish.

Jan 1, 1926

Jan 1, 1911

By J. V. Richards

The Altar district, State of Sonora, Mexico, is for the most part a desert with but little rain-fall and few running streams. On account of this scarcity of water it is necessary for the natives to " dry-wash" the placer-gravel, and the object of the present gaper is to describe some of the more commoil Mexican dry-mashing devices. My observations were confined to a property known as Las Palomas placers, 15 miles from the Gulf of California and about 150 miles south of the United States border; a brief description of which property may be of interest as illustrating what is, perhaps, a typical Sonora dry placer. It is said that as long as a century ago the Yaqui Indians discovered rich cement-gravel, known as argo masa, at Las Palomas, and that there has been a more or less steady production of gold from the property ever since. The argo masa, is a fairly-coarse gravel, the pebbles being quite firmly held together with a lime cement. Gold is scattered through this cement in particles ranging from fine specks to pieces several grams in weight, and occasional large nuggets are encountered. The contents vary so widely that it is difficult to estimate the average value, but returns of from $10 to $50 per cubic yard are common, and it is doubtful if the Indians considered anything less than from $4 to $5 a yard as "pay dirt.'' This ar-90 masa, occurs in channels varying in thickness from a few inches to several feet, and in width up to 300 ft. These channels are continuous and are probably ancient stream-beds. They are for the most part covered with an over-burden of a more recent gravel, varying from 30 to 50 ft. thick, and the fact that this over-burden contains values as high as $1.50 per cubic yard, and yet was not worked by the Indians, shows that their idea of what constituted mas high.

Jan 1, 1911

By Edward Keller

Under the title, Labor-Saving Appliances in the Works-Laboratory, I published a paper1 in which mas described how multi-manipulations in a works-laboratory and in the furnace-room of an assay-laboratory, can be condensed into single manipulations by applying the proper mechanical devices. For example, I now deposit ill, or withdraw from, a muffle a set of 48 cupels as one unit. The front row (8) of these are blanks or heaters; the other 40, when they have attained the proper temperature in the muffle, are charged simultaneously with the 40 lead-buttons. Three manipulations here accomplish an operation which by the generally customary method requires 136, and this number is only limited by the size of muffle and cnpels. This operation is an enlargement of what I have already described in my former paper, and Fig. 1 shows the improved implements. In the paper referred to I described a gold-silver bead parting-bath, which is the last of the devices used in regular sequence in practice. This bath mas designated as being convenient, but mas not a labor-saver properly. Fig. 2 of the present paper shows a new device. Instead of the original tray, there are now sectional holders for the test-tubes, each having a wooden handle on either end, so that the holders ma?-be removed from the boiling bath, and the acid or water poured oE from each set of tubes (in this case, 7) without waiting to cool. The tubes, held in place by clutches, as shown in Pig. 3, rest in holes in the base-strip, having a smaller diameter than the tubes. Each holder is stamped at either end with a number, so that the bath becomes further useful by permitting several men to use it at the same time without interference. Apart from the handles, the holders are made of sheet-copper.

Jan 1, 1911

By Eugene R. Rice

There are many methods for determining the meridian, but all of those in common use involve at least two separate observations, one for latitude and one for azimuth. Such observations made upon a south star at any hour are open to the objection of possible inaccuracy due to ignorance of the absolute refraction, and also to slow change in the altitude of the star when near the meridian. The method of observing a circum-polar star at elongation. besides requiring a separate observation for latitude, is open to the serious objection that clouds may obscure the star at the critical moment. Moreover, a tedious wait for the star to come to elongation is sometimes necessary. Many of us can recall 'long, cold, weary vigils, waiting for Polaris to reach elongation. For observing a circumpolar star at any hour, not only the latitude, but also the true time, must be known. This it is practically impossible to obtain, except in regions reached by the telegraph, and usually then one has to know the longitude also, in order to reduce " standard time" to " local time." The results obtained by this method, when the star is at culmination, are not very good, unless the true local time is absolutely known. The methods of obtaining the nleridian from the sun, by means of a solar attachment, or by direct observation, while good, are not absolute, by reason of refraction, change in declination of the sun, and small change in vertical angle, when the sun is near the meridian. For these two methods, latitude, time, and approximate longitude have to be known. In the method here described, only one observation is needed, and from it are computed azimuth, latitude, aud sidereal time. In other words, one call observe a circumpolar star—Polaris

Jan 1, 1911

By T. Lane Carter

It is a curious fact that while in our Transactions there are papers dealing with mining-districts in all parts of the world, in Europe, Asia, Africa, and Australia, there is not one which describes the mining possibilities of Nicaragua, our near neighbor. To be most interested in distant objects, like the moon, and to neglect what lies at our feet, appears to be a trait of human nature. The neglect of Nicaragua is not confined to the American Institute of Mining Engineers. In no other transactions am I able to find papers dealing with mining in Nicaragua, some parts of which are as much in need of discovery and research as the North Pole. I hope this paper will be the precursor of many others to be printed in our Transaclions, dealing not only with the miniilg possibilities of Nicaragua, but with the whole of Central America, where there are vast areas a,waiting skill and capital for their development. Much of this capital and skill should come from the United States in the future, although it is probable that European capitalists, when they appreciate fully the possibilities, will investigate more and more the mining-resources of Nicaragua and ot'her Central American republics. Fig. 1 is a sketch-map of Nicaragua showing the principal mining-districts. 11. History. Mining in Nicaragua did not begin yesterday. It was commenced by civilized man when the Spanish conquerors pene-' trated into the interior and forced the natives to procure the precious metal for them. It is strange that the Spaniards did not find more gold, and work on a scale as extensive as in Colombia and other parts of South America. Probably in Nicaragua the Indians covered up most of the rich prospects

Jan 1, 1911

By Edward W. Parker

At the Seventy-sixth meeting of the Institute, held in New York, N. Y., February, 1899,I presented a paper on this subject entitled, Coal-Cutting Machinery,' which has become somewhat out of date, in view of the decade's development in this feature of the coal-mining industry. It should be explained that the present paper is limited to the use of mining-machines in bituminous mines. Practically all of the anthracite mined is "shot from the solid," no undercutting being done. Anthracite-mining is therefore not considered in the statistics or other references. The statistical record as compiled by the U. S. Geological Survey shows that in 1898, the year preceding the presentation of my former paper, there were 32,413,144 short tons of coal undercut by the use of machines. In 1907 the machine-mined coal-product amounted to 138,547,823 short tons. In sympathy with the general decrease in coal-production during 1908, the output of machine-mined coal decreased to 123,183,334 short tons, but the proportion of machine-mined coal to the total output, nevertheless, showed an increase, from 35.1 per cent. in 1907 to 37 per cent. in 1908. In 1898 only 19.5 per cent. of the total product was unclercut.by the use of machines. The number of in use in the bituminous mines of the United States has increased from 2,622 in 1898 to 11,144 in 1907, and to 11,569 in 1908. The total production of bituminous coal in the United States in 1908 mas almost exactly double that of 1898, while the machine-

Jan 1, 1911

By F. T. Havard

The present truce in litigation between Western smelting and ranching interests gives opportunity for a summary of the results achieved by metallurgists in condensing fume and de-acidifying furnace-gases. In the absence of complete records of past experiments, there ha's been a good deal of unliecessary duplication of attempts and failures. Yet, especially uilder the recent policy of our large corporations, looking to the economic recovery of the values of by- and waste products, . original and, in some cases, effective measures have been developed by American metallurgists. In the case of Bliss us. the Anaconda Copper Mining Co., the Montana Suprenle Court, recognizing the progressive efforts made to render the flue-gases innocuous, and the value to the community of the smelting company's operations, refused to hamper its work, and returned a verdict in favor of the defendant. In the trial, the experimental farms of the company ill the so-called "aff'ected region" were proved to be thriving perfectly, showing that immunity was guaranteed to vegetation and stock by tlle wide distribution of the sulyhurous acid gas in the dry air of Montana. Indeed, L. S. Austin has proved that by the time the fume is 4,000 ft, distant from the stack, the percentage of sulphurous acid has been diminished from 2.28 to 0.00045; and Angus Smith has shown that rain must contain 40 parts per million of free acid before vegetation is affected. The arsenic in the stack-gases is but a very small part of the original content of the ore, of which 80 per cent. and over is rejected in the coilcentrator and furnace waste-products or recovered in the flues, Nevertheless, neither the peace in Montana nor the armistice

Jan 1, 1911

By Albert F. J. Bordeaux

Alluvial gold was first discovered in Guiana in 1852, in the sands of the Arataye river, by Paulino, a Braziliaii convict. During the following years, gold was found also in the rivers Orapu, CirubQ, etc. In 1873 the famous placers of the Sinnamary system were opened: Saint-Elie, Dieu-Merci, Adieu-Vat, and Couriege. This group of mines has produced nearly $10,000,000, according to official records, not including the gold that escaped the taxes. The discoverer was a mulatto named Vitalo. Except in a few rich spots, the gold was rather evenly distributed along the creeks. In one instance, gold was found in the red dirt from the slope of a hill, which, after transport to the creek, gave an amount of 150 kilograms. The placers of the Mana system, Enfin, Elysee, Pas-Trop-Tot, date from 1878, and their production has been about %g5,000,000. In 1888, the Awa placers, along the boundary bet.ween the French and Dutch Guianas, on the Maroni and its tributaries, were discovered. They have yielded $12,000,000. The only industrial company, the Dutch Guiana Freiich Minillg Co., produced in 15 years about 2,500 kg. of gold, worth $1,500,000. From 1893 dates the famous Carsewene discovery, in territory then in dispute between France and Brazil. A settlement was made recently in favor of Brazil, by arbitration of the Switzerland State Council. Carsewene is said to have produced about $18,000,000 in six years (1894-1900), but not even one-fourth of tho production went through French Quiana and

Jan 1, 1911

By N. H. Emmons

An interesting development of copper blast-furnace construction has been brought about in adapting the blast-furnace to be a "burner" for sulphuric acid making. When the Tennessee Copper Co. first decided to construct an acid-plant, the standard type of brick-top furnace, supported by structural steel, was the only one in use at its plant. All the tests for temperature and strength of gas had been made on these furnaces, and had been satisfactory. When, however, the acid-plant was put on the flue, and the flue had to have a damper put in it to force the gas into that plant, troubles began. The furnaces were fairly tight, and for a few months the work was quite satisfactory. Fig. 1 shows the old type of furnace-top used at the start. It was soon found that this top would not stand the temperatures, particularly when dampered back, as was necessary to force the gas into the Glover towers. The structural steel, of which the furnace skeleton was constructed, warped and twisted so badly that it was not safe to use the furnaccs. This effect is shown by Fig. 2, which is a photograph of old No. 4 furnace, after the brick-work had been removed. It became apparent that a new type of top mas necessary and the engineering force was started on the design of a new furnace-top, with the result that a low top, with brick-lined flues at each end below the feed-floor, leading to the main concrete dust-chamber, was constructed. This furnace, No. 7, is shown in Fig. 3. The charging-doors are made of cast-iron sections, three sections to a door, and three doors to a side. A door to the furnace was made of east copper, but the heat was great that the copper bent readily, due to the jarring of its

Jan 1, 1911

By W. R. Bacon

"The Canam property is in southern British Columbia, 24 miles southeast of Hope. It is reached by 5 miles of road from Mile 26 on the Hope-Princeton Highway.Between the years 1930, when the property was discovered, and I 938 development work by The Consolidated Mining and Smelting Company of Canada, Limited included some open-cuts and six adits totalling 2,700 feet in length. Canam Copper Company Ltd. explored the property intermittently from 1947 to 1955 by diamond drilling and underground work, including driving No. 10 adit. From surface down to the level of No. 10 adit, about 1,250,000 tons of ore has been outlined with an approximate grade of 1.25 per cent copper, 0.8 ounce silver per ton, and 0.01 ounce gold per ton. The ore in the upper part of the deposit also contains a little molybdenum and a little uranium.In June, 1955 Canam Copper Company Ltd. made arrangements to have the property brought into production under the direction of Mogul Mining Corporation Ltd. of Toronto, and a new low level adit has been started.GENERAL GEOLOGYThe principal rocks on the Canam property are chert, cherty argillite, and argillite. They are considered to be Jurassic or Lower Cretaceous in age. Although massive bands to 150 feet in thickness occur, these rocks are in general thinly bedded. Conformable bands of pyrrhotite, a fraction of an inch in thickness, are not uncommon in the well-bedded rocks, and fine tourmaline can be observed in various places.The sediments strike slightly west of north and dip quite steeply, generally eastward; however, sharp divergences from this general attitude are fairly common.Dark grey dioritic sills, in which slender prismatic crystals are conspicuous, are fairly common in the sediments. In general the sills are less than 25 feet in thickness, but a few are as much as 100 feet thick. Under the microscope the sills are seen to consist largely of amphibole (pargasite) and plagioclase (near An50)."

Jan 1, 1949

By A. J. Fenn

Long experience with underground mining inspired the unusual idea of using an underground crusher-conveyor system as a substitute for surface haulage at the Cananea open-pit copper mine in Sonora, Mexico. Now implemented and working well, the system has born out the expectations of its originator, Cia. Minera de Cananea S.A. de C.V., that it would effect substantial cuts in the high cost of haulage. The Cananea deposit is a large, low-grade orebody above the mined-out Colorada pipe which was once one of the largest high-grade underground deposits in the district. Present facilities at the pit consist of: (1) A large open-pit mine capable of moving 80,000 tons of material per day with a shovel-truck, underground crusher and belt conveyor haulage system. (2) A 25,000-tpd concentrator equipped for four stages of crushing, rod mill-ball mill grinding with cyclone classification, and flotation in conventional machines. (3) A dump leaching process producing 1 million lb of copper per month in a tin-can scrap precipitation plant. (4) A two-reverberatory, six-converter smelter which can make 140 tons of blister copper per day. (5) A well-integrated contingent of supporting departments running the gauntlet from housing to power generation.

Jan 3, 1969

By Robert C. Weed

Leaching in place at Cananea began in the 1920's on a limited scale. The first plants were small wooden boxes located underground in the Capote and Oversight mines, and output was low. Scrap iron was used as precipitant. Later several other small plants were started up. Leaching was limited entirely to underground areas, and production remained low. The Veta precipitating plant, the first on a larger scale, was put into operation in the late 1920's. After a period of intermittent service it was rebuilt in 1946 and has since been running continuously.

Jul 1, 1956

By C. V. Umipig, G. G. Hutalle, E. E. Israel

TVI Resource Development (Phils) Inc. Canatuan mine is a polymetallic ore deposit located in the Province of Zamboanga del Norte on the island of Mindanao in the Philippines. The deposit consisted of an oxidized capping of gossan overlying a Besshi type volcanogenic massive sulphide lens which is near surface and flat lying. Construction and development of a sulphide processing plant began in early 2007 and commissioned in November 2008. During the initial stages of sulphide operation, high copper (Cu)-low zinc (Zn) ore was fed to the plant. Marketable copper concentrate at 91-95% recovery was produced utilizing a high-pH bulk sulphide rougher flotation and 2 cleaning stages. Because of increased levels of Zn of the ore body, a Cu/Zn separation circuit was initiated in early 2010 following an intensive laboratory test work program. This Cu/Zn separation circuit was necessitated because of the copper ion pre-activation of the sphalerite that lead to the zinc being readily recovered to the copper rougher concentrate. In-situ activation of zinc (in the pit and stockpiles) was caused by the leaching of secondary copper minerals in the ore (particularly from the dominant copper species, chalcocite and covellite). This problem required the development of metallurgically complex and intensive reagent regime to effectively depress the activated sphalerite. As well, the immediate reactivation of zinc after it has been depressed, at the onset of Cu/Zn separation flotation, added additional metallurgical complexity to the process. Subsequent to the Cu/Zn separation circuit, an unconventional, yet proven effective, simultaneous cyanide detoxification-zinc flotation circuit was set-up to recover the zinc. Laboratory test work results realized Cu-Zn recovery differential from a Cu/Zn separation circuit of over 40-45%. This performance has been achieved in the plant, at 72% Cu overall recovery. With the gradual improvements on-going with zinc circuit capacity and effective zinc separation being achieved, zinc recovery has currently reached 40%.

Jan 1, 2012

By Geno Saccomanno

INTRODUCTION Cancer of the lung in uranium miners has been reported by many authors. In fact, it has become a most popular subject for comment by environmentalists, health physicists, and newspaper writers. I believe it appropriate for me to discuss cancer of the lung in uranium miners in a general way commenting briefly on etiology, incidence, tumor cell types, and particularly, tumor development and treatment. Cytological development of cancer in its incipient stages, particularly the in situ stage, relates to potential cure with photoradiation, early diagnosis, and treatment. Our observations of the cytological response to this modality of diagnosis and treatment will be discussed briefly since this area will also be covered by Doctor Balchum. The cause of lung cancer in uranium miners is primarily due to two carcinogens; cigarette smoking and radon daughter radiation. Cigarette smoking has continued at the same intensity over time among uranium miners; about 60% of the miners are cigarette smokers and 40% are non-smokers. Radon daughter exposure to the uranium miner has varied from mine to mine, but over the last 20 years has been reduced to a minor fraction (.3 WL) of the level that prevailed in many of the mines during the 1950-1960 era when many of the miners were exposed to more than 10 WLM. Sputum samples have been examined on as many uranium miners as responded on the Colorado Plateau since 1956. Autopsy studies were done whenever this was permissible. In some instances, only tissue from a biopsy of a node or lung was available for study. Smoking histories were also taken. Approximately 200,000 sputum samples were examined and histological examinations of lung lesions were made from 312 cases. METHODS The method of sputum cytological collection and preparation was reported previously. I The lungs were fixed with formalin and prepared for sectioning by Dr. Oscar Auerbach with his block-section method. RESULTS Three-hundred-twelve lung cancers from uranium miners were examined. The tumor types and the age at death for each type, smokers and non-smokers, are given in Table #1. The incidence of the tumors in the smokers and non-smokers is given in Table #2. The incidence of small cell carcinoma of the lung has decreased from an incidence of 76% of all the lung cancers found in uranium miners to 22% of these lesions (Figure #1). The decrease in incidence of this tumor is probably due to decreased exposure to radiation in the mines.

Jan 1, 1981

By L. Wolofsky

"The Candego property is in Boisbuisson and Christie Townships, Quebec, about 13 miles south of Marsoui, a village on the north coast of the Gaspe peninsula, 80 miles east of the railhead at Matane. It was the first producing mine in the peninsula. Production to October 1954, when operations were suspended, totalled 68,497 tons of ore, which yielded concentrates containing 8,706,535 lb. lead, 5,870,272 lb. zinc, 355,526 oz. silver, and about 1,000 oz. gold. The property was acquired by the present company in the summer of 1955.The mine has been developed by seven adits, driven into the west slope of the valley of the Marsoui River. The river here is at an elevation of about 1,600 feet, and is roughly 1,500 feet below the level of the adjacent upland. Adit elevations range from 1,760 to 2,330 feet. Five of them are in one vertical zone, on what was originally believed to be a single vein. Past production has come from Nos. l to 5; the chief present high-grade ore reserves are in No. 7.The author's observations were made in adits Nos. 3 to 6, in several of the old pits, in the surface trenches, and on drill core, at various times between December 1952 and September 1953. Much of the surrounding area has been mapped by Jones (I) and McGerrigle (2) for the Quebec Department of Mines. H. M. Kingsbury served as consulting geologist to the mining company for several years.General GeologyThe Candego veins occur in Lower ( ?) Ordovician sedimentary rocks which form a strip about 15 miles wide along the north coast of the Gaspé peninsula. The series includes limestones, shales, and sandstones, mildly metamorphosed in places. Three miles south of the mine is the north contact of the granitic intrusive, regarded as Lower or Middle Devonian, which underlies the Tabletop Mountains area. This batholith is about 10 miles long, in a north-south direction, and about 4 miles wide. At Mount Albert, about 5 miles west of the Tabletop intrusion, is a group of basic rocks, amphibolites and serpentinized peridotites, thought to have been intruded at the close of the Ordovician."

Jan 1, 1949