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By L. C. Graton

Introduction The Porcupine district of northern Ontario has yielded over $300,000,000 in gold during its twenty-three years of mining operations. It thus ranks among the foremost gold producing areas of the world. Of this $300,000,000 already produced from the District, the Hollinger mine has furnished over 60 per cent and stands as one of the greatest gold mines of all time. In 1929, the Hollinger Directors decided to supplement the current geological and development work by an intensive investigation of the geology of the mine. This special study, begun in June of that year, was completed in October, 1932. An account of the geology of the mine in a degree of detail commensurate with the intensity of the study is in course of preparation. But the widespread interest manifested at the present day in gold occurrence generally, in Canadian gold deposits, and in the specific results of the investigation at Hollinger, appears to justify the immediate presentation of a highly abridged summary of our principal findings, insofar as they relate to the more general and scientific phases of the geological situation. Those conclusions having direct bearing on operating and exploratory policy are not dealt with here. The present preliminary paper, therefore, records chiefly the conclusions reached, with little incorporation of supporting argument or evidence. While intended to give a reasonably balanced perspective of Hollinger geology, the condensed presentation naturally emphasizes those views which are not in complete accord with accounts hitherto published regarding this district.

Jan 1, 1933

By Kadri Dagdelen

Recent trends of the mining project show that there will be more and more mechanized, largescale mining operations with complex process options to make low grade deposits economically feasible to develop. The global optimization of large scale, complex mine operations will become more important for the future mining. To serve the industry?s future needs, the OptiMine® software program is developed based on expertise gained at the Colorado School of Mines (CSM) for more than two decades, by using the special solution methodology based on the Mixed Integer Linear Programming (MILP) technique in the Operations Research (OR). The program has been beta-tested on more than 20 projects as a multi-time period scheduling and cutoff grade optimization tool that handles large scale open pit and underground mining operations involving complex process options, many stockpiles and dumps, blending requirements, and truck hour limitations. In each project, various operational options are evaluated in OptiMine® to develop strategic planning to help defining company?s strategies and directions. This paper demonstrates how the OptiMine® can be used to optimize a large scale, complex production scheduling problem on a case study coming from real world project. The case study describes multi-pit mine production scheduling optimization with pit backfills in such a fashion that acid generating waste rocks are encapsulated to minimize environmental impact.

Oct 1, 2009

By H. C. Gunning

DURING the past year the Cadillac-Malanie area in northwestern Quebec has been catapulted to the front as one of Canada's most active gold mining districts. Late in 1934 the area was lolling along in the doldrums, with one producing mine and a handful of active prospects. 1935 passed with only slightly increased activity, but saw the start of production at Canadian Malartic mine. Lightning struck in April, 1936, when a new and phenomenally rich ore-body was found in O'Brien Gold mine, and by midsummer the camp was ablaze with activity. An important new discovery on the Pan-Canadian property, and pleasing underground developments at Sladen Malarric, East Malartic, and Lapa Cadillac, in addition to other new developments, lent fodder to the flame, and at present several dozen properties are being actively developed. For the past three seasons, the Geological Survey of Canada has been engaged in a fairly detailed study of the geology and mineral deposits across Cadillac, Malarric, and Fourniere townships. Ir is the purpose of this paper to present a brief preliminary statement of the structural and economic geology and to discuss some of the more important problems that have been found to exist. The reader is requested to remember that the paper is a preliminary one and that therefore the conclusions presented are open to revision. It is impossible to make full acknowledgment for help received, for the writers are indebted to practically every operator and prospector in the area for generous co-operation in the work, and to several private, provincial, and federal geologists for data and frank discussion of problems encountered. Over a score of student assistants from McGill, Queen's, and Toronto have given excellent service. Published reports by Wilson, Cooke, James, Mawdsley, L. V. Bell, and J. J. O'Neill greatly facilitated the work. For adequate control surveys and a topographic base-map, the writers are greatly indebted to H. N. Spence.

Jan 1, 1937

By T. Donkin, B. Patterson, M. I. Guthrie, J. T. Ross

"The interest in the use of sensor-based particle ore sorting has increased significantly with the recent advances in the sorting technologies and higher capacities per unit. This technology has the potential to provide great value in processing lower grade ores from the mine whilst delivering higher grades to the mill as well as in upgrading waste rock into ore. Typically, the focus is on the amenability of the ore to ore-sorting and associated reductions in the consumption of energy, water and consumables. However, layout has a significant impact on the installed cost of a concentrator and the layout impacts from fitting an ore-sorting circuit into the concentrator plan need to be carefully considered. This paper examines layout considerations that play an important role in ore sorting projects. These include additional crushing and screening requirement, transportation of the rejected material back to the waste stockpile (mine fleet requirements) and effects on concentrator footprints.INRODUCTION Ore sorting has been practiced throughout history with an early report by Agricola in 1556. Metallic and non-metallic minerals were extracted from rocks by laboriously breaking them with hammers and picks and hand-picking selected material with higher grade off a table. The concept has not changed but the sorting technology has evolved significantly over the last 20 years. Ore sorting is usually a dry process in which a portion of the material is rejected based on mineral properties and/or grade. The methods used for sensing ore particles cover a large range of physical properties. A variety of sensors are available that differ on the discrimination technique that is used, which include: photometry, radiometry, conductivity, magnetism, microwave, X-ray transparency: X-ray transparency and luminescence and UV fluorescence (Sivamohan and Forssberg, 1991; Wotruba, 2006). There are two main ore sorting techniques: particle ore sorting and bulk ore sorting. According to Nadolski et al (2018), the potential for sorting is determined though analysis of grade heterogeneity within the orebody (greater heterogeneity represents more opportunity to add value to a project) at the scale of the intended sorting unit size."

Jan 1, 2019

By W. H. Moore

It seems necessary, at times, that we should reconsider some of the more obscure causes that lead to explosions of gas and coal-dust in mines, in the hope that a recapitulation will keep before us that old and true saying "eternal vigilance is the price of safety". This explosion, while not extensive (resulting in only two much to be regretted deaths) enlarged our vision as to the possibility and probability of other explosions with more disastrous results. As this is only a partial report I shall have to omit many things that are generally included in describing a mine explosion. The mine was worked exclusively with electric cap-lamps -only firebosses and other officials carried safety-lamps. All shots were examined and fired by firebosses with a small hand-battery. Monobel was used exclusively for blasting, and clay for tamping. The system of haulage iri use was main-rope and winches, horses being employed for gathering. Compressed-air was the motive power for all winches and pumps, excepting the pumps at the shaft-bottom which were steam-driven. The mine was wet with practically no dust anywhere, except what was being made at the coal-face in the getting of the coal. Gas was found occasionally, generally in the brushing, especially where the brushing was carried up to a small seam, 2 to 6 feet above the main seam. The place where the explosion took place was known as Leigh's heading, which was being driven to the rise, immediately inbye of the siding (off No. 1 left, off the new slope) and was about 90 feet up from the level.

Jan 1, 1926

By J. O. Wheeler

"DEFINITION OF THE REGION, ITS BOUNDARIES, AND PHYSICAL AND GE'OLOGICAL CHARACTERISTICSTHIS PAPER concerns the Western Cordilleran region, embracing most of British Columbia, the southern half of Yukon Territory and the southwesternmost part of the District of MacKenzie. It excludes Vancouver Island and the Queen Charlotte Islands, which are discussed in a background paper on the Pacific Continental Shelf. The region is bounded on the south by the northwestern United States, on the west by the continental shelf and Alaska, on the north by the front of the Ogilvie Mountains, on the northeast by the axis of the MacKenzie Mountains and on the east by the Rocky Mountain Trench.The region is dominated by two mountain chains that con tain icefields and glaciers: the St. Elias, Coast and Cascade Mountains in the west; the Selwyn, Pelly, Cassiar, Omineca and Columbia Mountains in the east. The Intermontane region between these mountain chains consists of lower mountains and plateaus. In the mountains, the region above the timberline and many of the steep valley-walls provide good exposures of rock, but these areas are subject to rockslides and landslides and in winter to snow avalanches. Much of the Western Cordillera was covered by ice-sheets at various times during the Pleistocene epoch. Consequently, the larger valleys in the mountains and much of the Intermontane region contain much glacial drift and alluvium and only limited exposures of rock. This same terrain in the Southern Cordillera, however, is the most favourable for agriculture. Parts of the region, particularly in the two mountain chains, are heavily forested. Elsewhere, the forest cover is less, with grassland prevailing in the south and tundra in the north."

Jan 1, 1970

By M. E. Grimes

"The future of the uranium industry in Canada during the next twenty years will be very dependent on political and social issues on a world scale. Technology, as such, will tend to be of lesser importance. Nonetheless, some technical changes can be anticipated.This paper deals with milling of uranium ore, leaving further processing and nuclear power production to specialists in these fields. An attempt has been made to look at uranium production technology in Canada in relation to that in other countries, and to draw interference regarding future changes that seem probable in the Canadian context. In particular, recent advances in mill equipment are considered.The chemistry of uranium and its relatively low concentration in most ores has been responsible for a completely hydrometallurgical approach to mill processing, and this should continue. In spite of little commercial success to date, pre-concentration of lower grade ores will be researched further in order that these ores can compete with higher grade deposits in Canada.The discovery of the relatively high-grade ores of the Athabasksa region will undoubtedly influence choice of mill processes and equipment. The potential effect on innovations is discussed"

Jan 1, 1986

By E. Asselin, P. Sauve, H. Salomon-de-Friedberg

"Residues from the CESL Copper process were leached using the CESL Gold process. The kinetics of reaction were confirmed to be fast with over 50% of the gold consistently extracted within 2 minutes of leaching. Final gold extractions under the conditions tested here were between 80-90% obtained within 90 minutes. A model for the CESL Gold process was developed. This model is slightly different based on whether the copper concentrate leach residue was ground or unground prior to leaching: the gold leaching rate constant is approximately twice as fast for the ground samples. Unground residues had a P80 of 13 ?m whereas ground residues had a P80 of 10 ?m. The model predicts a 43% decrease in leaching time for ground residue versus unground residue to achieve the same extraction under otherwise identical conditions. The model was more accurate for the ground samples. INTRODUCTIONTeck's CESL Process (Jones, 1996) was developed to provide an economically attractive alternative to traditional copper smelting. It has since evolved to also deal with copper concentrates containing valuable impurities such as nickel and undesirable ones, such as arsenic, while reducing downstream costs. Effective recovery of gold and silver is essential to the economics of the CESL Process. The Brook Hunt 2007 copper concentrate assay data (Wood-Mackenzie, 2007) were examined to determine the ratio of gold plus silver value relative to the contained copper. As indicated in Figure 1 below, nearly two-thirds of concentrates have 10% or more of their total value tied up in their precious metals content.CESL has extensively examined the recovery of gold and silver at bench, pilot and demonstration scale, which has culminated in the present CESL Gold Process (Barr et al., 2007). The process targets the precious metal contained in the leach residues produced in the copper portion of the flowsheet. This residue has two primary components which influence downstream processing. The major iron-rich fraction (-75 wt%) of the residue is a mixture of various forms of iron oxide precipitates including hematite and jarosite (Sahu and Asselin, 2011). The iron fraction ranges from amorphous to crystalline in nature depending on the compound precipitated, upstream operating conditions and feed material composition. The lesser, but by no means less important, fraction is a mixture of elemental sulphur and unreacted sulphides (principally pyrite).Elemental sulphur formed during the oxidative leach of the copper concentrate reacts with cyanide to form thiocyanate (SCN-) making a traditional cyanide leach approach too costly. Since the SCN formation reaction strongly depends on contact time with the CESL residues (Po, 2007) short contact times were preferred. This factor guided the development work towards the eventual room temperature, pressure cyanidation process which results in near complete gold dissolution in 90 minutes. A recent CESL gold demonstration campaign treating 1.5 t/d of residue from the copper oxidation step achieved an average gold extraction of 91% (96% maximum)."

Jan 1, 2012

By Ozdemir. O.

Magnesium additions to aluminum enhance strength and hardness, lowering density, and improving corrosion resistance. However, during melting and casting processes, significant amounts of magnesium are lost due to selective oxidation. Preventing these losses would reduce the production cost and improve the quality of the final product. The effects of strontium addition on the oxidation behaviour of aluminum-0.5% and 1% magnesium alloys were investigated by monitoring sample weight gains with time with a thermogravimetric balance at 750°C. Sample cross sections have been examined using Field Emission Gun Scanning Electron Microscope.

Jan 1, 2004

By E. T. W. Bailey

A HISTOR Y of the development and application of instruments, from the simplest U gauge to a modern indicating recording controller, would contain many interesting accounts of difficulties experienced and over-come. Important as is the history of development to any branch of science, this phase will, of necessity, have to be omitted from this paper and remarks confined to the results from the use of instruments in their present form. The steel industry bas, in the past decade, become increasingly instrument minded. More than ever, economy and adherence to doser specifications are demanded, and any tool that will aid in attaining these objectives by intelligent application and use finds a ready acceptance. The open-hearth furnace bas offered a field for instruments which is different from almost any other and one in which even a small percentage saved in operating costs may represent a considerable sum. Nevertheless, this department of the steel industry has been more cautions than most others in accepting the benefits which automatic control bas given on many other types of industrial furnaces, and one is puzzled why open hearths have not more generally benefited by the application of controlling instruments. The furnace operator bas to adjust the same three main valves that control fuel, combustion air, and stack draft as on most other furnaces, with the additional regulation of reversing the furnace. He is just as aware of the importance of proper draft control and correct air volume to burn most economically the applied fuel as any good boiler-plant engineer. What, then, are the special conditions that pertain to the open-hearth furnace?

Jan 1, 1939

By L. McFarlane, D. Rollwagen

"Madawaska Mines produces a uranium precipitate (83-85% u3o8) using a magnesium oxide slurry to precipitate the uranium from solution. The solution, at approximately 9""0 g/l u3o8 is neutralized to a pH of 7.0. At the Eldorado Nuclear Refinery in Port Hope, the precipitate is not acceptable as a single feed to the refinery process. It was discovered that a 2% silica impurity caused emulsion problems in the solvent extraction column.After extensive studies of possible solutions, such as two-stage precipitation and solvent extraction, an acceptable solution was found. The selective precipitation of uranium at a pH of 3.5-4.0 using Hydrogen Peroxide produces an almost silica free product of higher purity (90-93% u3o8) to that of straight magnesium oxide precipitation. Introduction Madawaska Mines Limited is located four miles southwest of Bancroft, Ontario. The annual production of u3o8 is approximately 610,000 pounds. To produce the final product or yellowcake, nine separate steps are required. These are (1) grinding, (2) dewatering, (3) leaching, (4) acid filtration, (5) clarification, (6) ion exchange, (7) precipitation, (8) washing, and (9) drying and packaging. To illustrate these steps, a complete flowsheet of the mill is displayed on page three.The yellowcake is sent to Eldorado Nuclear Limited in Port Hope, Ontario for further concentrating and refining. As part of their routine specification check, a test called the amenability test is performed. This test indicates how a particular dissolved yellowcake product reacts to solvent extraction. The Madawaska yellowcake did not pass the test."

Jan 1, 1982

By Balmer Neilly

We are regularly told that before making a new investment one should seek the advice of his banker. If we were to place the subject matter of this paper before bankers. other than those who have experience in our mining camps, their reply would probably be evasive. However, if for example: a mining company asks them for a loan and offers as security certain mining investments, they are, in most cases, explosively candid. The idea is preposterous, unless, under Section 88 of the Bank Act, the mining company is able to deposit with the bank, gold or silver bullion, to an amount sufficiently in excess of the loan, to provide for what the banker describes as a reasonable margin of safety in case of contingencies. In addition the directors of the mine personally must jointly and severally guarantee payment of the loan. With any of these conditions missing the banking atmosphere becomes chilly. The local manager explains that the general situation, and particularly European conditions, are so unsettled that head office has warned him that his discretionary powers must not be exceeded under any circumstances.

Jan 1, 1924

By Angus D. Campbell

"IntroductionThe subject assigned to me tonight gives unlimited scope. The material available is so voluminous and leads into so many ramifications, and the memories of the Camp are so vivid and treasured, that it is difficult to decide just what to use. Then, too, the geologists are the story-tellers of our tribe - I am only a hard rock miner.Members of the Cobalt Branch and Cobalters everywhere will agree without question that this Cobalt camp has been the greatest of all influences on Canadian mining. To those who do not know Cobalt, our opinion may seem prejudiced and our statement exaggerated.Be that as it may, discussion on this subject can be profitable, since it is worthwhile now and then to think on 'whence we came' and 'where we are going'.In the revival of interest in the Cobalt camp, we hope our guests may feel some of the old Cobalt Spirit, which has become the Spirit of the North.Visitors may even, while here, catch a glimpse of that whimsical little guardian spirit of the camp - the original goblin, the Kobold - for which Cobalt was named.While Kobold brings that good luck which plays so important a part in mining, he can have his evil moments, as in his original German home. There, when he made the silver disappear from their good ore, they cursed the grey ore, calling it Kobold.Although this little goblin bas frequently upset our best mining plans and geological calculations, be has played the game as well. He placed •some silver on the surface, and when he hid ~t at depth he left dues .for its finding. He has rewarded many who sought his treasure and is still rewarding those who have persevered and had faith in him. t:lis influence and that of Cobalt camp has probably had a greater influence on your work and your mining areas than you realize"

Jan 1, 1950

By CRO CRO

Elk Valley Coal?s Cheviot Project is located in the Alberta foothills south of the town of Hinton. The mine has been in operation now for the 3 years. The start up and subsequent operation of the Cheviot project has been directly influenced by the Cardinal River Mine. As the Cardinal River Mine was winding down due to reserve depletion in 2004, the price of seaborne traded metallurgical coal jumped to record levels and customers began aggressively seeking new sources of supply. Several months later, the owners of Elk Valley Coal decided to begin mining at the Cheviot mining area, extending the life of the area?s operations by over 25 years. The Cheviot Project had been delayed by low coal prices, ownership changes and a complicated and lengthy regulatory process fueled in large measure by stiff opposition from a number of major environmental organizations. Chief to the startup of the project was the construction of a 23-kilometer-long haul road that would connect the new coal measures to the existing Cardinal River processing and rail facilities. Construction of this road was completed with the first coal truck making its first trip in October 2004. This paper will look at some of original assumptions, the actual mining experiences and the lessons that were learned while moving from the drawing board to the current development as it exists today.

May 1, 2007

By J. A. Muñoz

In this work, short and long-term tests were performed using different massive mineral sulfide specimens (chalcopyrite, pyrite, sphalerite, galena, covellite and chalcocite) of museum grade and quartz of analytical grade in an acid medium containing silver ions. After attack, the samples were observed by SEM and products characterized by EDS. Parallel, massive specimens of pyrite (FeS2) and chalcopyrite (CuFeS2) were embedded in an epoxy resin, either electrically isolated or in electrical contact, and treated with silver ions in the presence of bacteria. Finally, massive chalcopyrite and pyrite electrodes were subjected to electrochemical measurements in an acid medium under different experimental conditions (addition of silver ions and inoculation). The results showed that silver deposition takes place preferentially on specific mineral surfaces: chalcopyrite, galena, covellite and chalcocite. The chemical reaction of silver ions with pyrite and sphalerite was negligible at low silver concentration (8 ppm). But sphalerite reacted with silver ions at higher silver concentration (100 ppm). In a mixture of chalcopyrite and pyrite, silver was deposited on the former surface creating new cathodic sites which sped up the electrochemical reactions of chalcopyrite dissolution.

Jan 1, 2007

By Lawrence Devon Smith

The selection of the production rate is one of the most crucial decisions to be made in the development of a mineral property. However, it is not uncommon for the production rate to be decided arbitrarily, before any technical evaluations begin, and it is often not reconsidered when better data becomes available. A number of methods are used in the mineral industry to select the production rate for a project. There is general agreement that the size of the ore reserve has a strong influence on this decision, but what other factors are involved? Is there a way to identify an optimum rate? This paper examines the factors that influence the selection of a production rate from the perspective of project economics. The NPV maximum value should be viewed as a “failure” point. The “two times capital” maximum is proposed as a lower limit. A practical check is suggested to confirm that a selected rate is in an optimum range. Production rate assumptions are much more likely to be reviewed for marginal projects, but they should also be reviewed for viable projects.

Jan 1, 1997

By E. Y. Carlson

"IN A SHORT PAPER it is impossible to do much more than to list the industrial minerals found in Saskatchewan and to give a brief description of the activity associated with each. I will not attempt to discuss the geology. It is sufficient to say that the settled part of the Province is covered by glacial drift which varies in thickness from a few feet to several hundreds of feet, and that this has hindered the search over much of the Province.CLAYA notable exception to this is the Cypress Hills area in the southwest corner which did not suffer any glacial action and where we find some of the large exposures of Cretaceous clays. In this area, the majority of the deposits are of stone-ware clays which are •an excellent raw material for such products as face brick and sewer pipe. Although the clay cannot be transported over any great distance it is used extensively in Alberta and Saskatchewan in the production of these products."

Jan 1, 1959

By J. O. Wheeler

"DEFINITION OF THE REGION, ITS BOUNDARIES, AND PHYSICAL AND GE'OLOGICAL CHARACTERISTICSTHIS PAPER concerns the Western Cordilleran region, embracing most of British Columbia, the southern half of Yukon Territory and the southwestern most part of the District of MacKenzie. It excludes Vancouver Island and the Queen Charlotte Islands, which are discussed in a background paper on the Pacific Continental Shelf. The region is bounded on the south by the northwestern United States, on the west by the continental shelf and Alaska, on the north by the front of the Ogilvie Mountains, on the northeast by the axis of the MacKenzie Mountains and on the east by the Rocky Mountain Trench.The region is dominated by two mountain chains that con tain icefields and glaciers: the St. Elias, Coast and Cascade Mountains in the west; the Selwyn, Pelly, Cassiar, Omineca and Columbia Mountains in the east. The Intermontane region between these mountain chains consists of lower mountains and plateaus. In the mountains, the region above the timberline and many of the steep valley-walls provide good exposures of rock, but these areas are subject to rockslides and landslides and in winter to snow avalanches. Much of the Western Cordillera was covered by ice-sheets at various times during the Pleistocene epoch. Consequently, the larger valleys in the mountains and much of the Intermontane region contain much glacial drift and alluvium and only limited exposures of rock. This same terrain in the Southern Cordillera, however, is the most favourable for agriculture. Parts of the region, particularly in the two mountain chains, are heavily forested. Elsewhere, the forest cover is less, with grassland prevailing in the south and tundra in the north."

Jan 1, 1969

By W. B. Timm

Introduction In preparing this paper on Recent Developments in Gold Milling Practice, the idea occurred to me that possibly the best way to deal with the subject would be to take you in thought on a visit to the principal gold mining camps of the Dominion, starting at the east and finishing up in the west, and noting, as we go, the outstanding improvements that have been made in the last few years in the practice of gold milling. Before beginning this tour, I desire to emphasize the debt this country, and particularly our mining industry, owes to that body of trained and experienced men, little heard of, but who, working quietly on their problems, are responsible for these improvements. The metallurgists, to whom I refer, have solved many difficult problems for the mining industry, in connection with the treatment of our complex ores; for instance, the silver-cobalt ores of the Cobalt district, the gold ores of the Porcupine district, the gold-telluride ores of the Kirkland Lake? district, the copper-gold ores of Noranda, the arsenical-gold ores of the Beattie mine, the copper-zinc ores of Flin Flon, and the lead-zinc ores of Kimberley. In doing so, they have maintained the high technical standards of the profession, and the practices thus evolved are noteworthy for their high degree of efficiency. When the price of gold increased from $20.67 to $35.00 an ounce, what had formerly been thought to be a low tailing became almost an ore, so that the metallurgists are now busily engaged upon the problem of putting this railing back in its proper place of being a tailing once more, or from its value, at the present price, of anywhere from 50 cents to a dollar or so per ton, to a few cents per ton. Owing to the changing prices of the metals in the world's markets, still greater improvements in metallurgical practices are imperative. An important contributory factor towards improvement in ore dressing is the aid furnished by the microscope in the examination of ores and mill products. By making possible the determination of the mineral constituents of the ore, their association, and grain size, it gives the investigator a knowledge of his problem, before he does any actual test work. In the Mines Branch laboratories at Ottawa, its use has enabled us to predict how an ore should respond to various methods of treatment.

Jan 1, 1935

By Francis Wm. Gray

The preparation of a paper read before this Society in 1927 on Undersea Mining led to representations to the Deputy Minister of Mines at Ottawa, Dr. Chas. Camsell, and to the Director of the Geological Survey and the Director of the Mines Branch, which resulted in the undertaking by these bodies of a geological, physical, and chemical survey of the Sydney coalfield, combined with revision of the geological maps, on all of which much progress has been made. Preliminary studies revealed the necessity for a new base-map on a scale that would permit the representation of the whole coalfield from cape Dauphin to Mira bay on one sheet, and in the making of this map the Geodetic and Topographical Surveys have collaborated, with the assistance of airplane surveys for filling-in of detail. The new map will show all the data accumulated by 50 years of active mining and will show also the extent of mine workings, with level-contours under the sea. Dr. W. A. Bell, of the Geological Survey, has, over a number of seasons, studied in the field the historical geology with the purpose of elucidating the sequence of earth movements that have determined the structure of the coalfields, especially those that have governed the course and extent of the complementary folds that traverse the Sydney coalfield. Dr. B. R. MacKay, of the Survey, and the officers of the Fuel Testing Laboratories at Ottawa have made exhaustive studies of the Phalen seam, chemical and microscopic, intended to elucidate the conditions under which this seam was deposited, and some very interesting conclusions have been reached.

Jan 1, 1934