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By T. M. Siew

"This paper begins with a brief discussion of the geology of the Newfoundland Zinc Mine area. The results of groundwater studies and pumping tests are then presented. It was decided that groundwater in the mine could best be controlled by conventional sump pumping and grouting. The system is fully described, as well as plans for improvements on the method. LocationThe Newfoundland Zinc Mine is located in the Great Northern Peninsula of Newfoundland, six miles northeast of Daniel's Harbour. The mine is situated at an elevation of approximately 350 feet above sea level, 5 miles farther inland , west of the long range of mountains which rise abruptly with elevations of over 2,000 feet above sea level.GeologyThe ore deposits occur in lower Ordovician carbonate rocks that form part of the stable St. Lawrence platform, which is mainly composed of (1) the lower Cambrian Labrador group, (2) the upper Cambrian to lower Ordovician St. George group, (3) the disconformity overlying Middle Ordovician limestones and shales of the Table Head formation and, (4) two overlying klippen composed of Cambrian and lower Ordovician rocks.The ore deposit is a Mississippi Valley type of the Tennessee variety, having proven are reserves of 5.3 million tons averaging 9.70/0 zinc from eleven ore zones which exist in an area of 5.5 square miles.Among these ore zones, the L zone is the major underground mining area, and is by far the largest of the known deposits. It has proven are reserves of 3.4 million tons with 11.5% zinc; this underground development has been inprogress since 1974.Stratigraphically, the orebody, which occurs about 300 feet below the disconformities between the Table Head and St. George formations, is situated in the upper St. George formationof lower Ordovician age.The upper St. George formation of the L zone is divided into three main units (Fig . I) : the underlying lower limestone the middle grey dolomite pseudo breccia unit and the overlying siliceous dolomite unit. In this area of the mine, the beds of the St. George formation dip gently west to northwest to 10 to 15 degrees. The orebody, which is generally strata controlled with a southwesterly plunge and which has the form of thin, narrow, but elongate, en-echelon ore bed s, is contained in grey dolomite pseudo breccia. Its dimensions vary from 50 to 900 feet in width and 8 to 120 feet in thickness, and the over-alllength exceed s 6,000 feet.The surficial deposit of the area is a till comprising a heterogeneous mixture of sand, gravel, cobbles and boulders, with an average depth of 20 feet."

Jan 1, 1980

By D. W. Li

Due to the ultrasonic testing and mechanical wind speed sensor have high requirement for the environmental of the coal mine, the charge induction wind speed detection method based on wavelet analysis is proposed. The same wavelet disturbance detection method is used at a fixed distance to obtain an induction signal to obtain a pass time, and then calculate the magnitude and speed of the wind. Simulation and verification experiments show that the method has application across a wide range of test speeds (up to 60 m/s). The metal probe causes little pipeline flow field interference. The method is particularly well-suited to dusty environment, and does not cause dust deposition through long-term operation. It can be widely used in coal mines for point wind speed continuous online testing.

Aug 1, 2013

By M. Maccagni, J. Nielsen

"The recovery of lead from battery paste has been investigated for a long time and with the use of many different electrolytes. A number of processes have been presented, but none of them reached even the demonstration step. Engitec has developed a new concept for the battery paste electrowinning using a chloride electrolyte fed through a very innovative flow cell. The process has passed the lab and the demo scale and it is ready to be introduced on the market. In this paper, a description of the process will be provided.INTRODUCTIONThe need for improved energy storage systems as well as the introduction of commercially viable electric vehicles is providing a strong compulsion toward the research of new batteries. The lead battery is playing an important role because it is inexpensive, reliable and it is the most recycled material. This last aspect marks the lead acid battery as quite peculiar making it both the primary lead based product and the main raw material for lead production.In the last years the legislative pressure has become very strong and has forced the lead production to react through the introduction of important process innovations and market changes. The dispersive products, such as additives for paints and for fuel as well as bullets, have been practically banned all over the world while the battery market continues to grow. The lead acid battery remains the cheapest and most integrated energy storage system available and is improving to meet the new technical challenges. This is testified by the news coming from the development of new and more efficient lead acid batteries which are confirming their leading position.Unfortunately, the image of lead is very negative in the public opinion and some important actions are required to try changing this sentiment. Among them, better information to the market and users and the introduction of new and cleaner technologies in the production of lead can help."

Jan 1, 2016

By Franc R. Joubin, Donald H. James

"The Property of Rix Athabasca Uranium Mines Limited is in the Beaverlodge area of northwestern Saskatchewan. The mine is 7 miles by road north from the Lake Athabasca port of Bushell which is 250 miles north by aircraft or boat from railhead at Waterways, Alberta.The Rix property is a portion of the former DD 1 concession, obtained in 1949 from the government of Saskatchewan when private prospecting for uranium became permissible. The concession was prospected in detail during the 1950 and 1951 field seasons and a great many radioactive show-ings were discovered. Development and drilling were concentrated in two and later three of these areas, and by late 1952 enough ore had been indicated in the Leonard series and ""Smitty"" zone to justify underground development by adit-drift and shaft respectively.Four hundred feet of drift development on the Leonard No. 1 vein and the sinking of a two-level vertical shaft with related lateral development on the Smitty zone were completed in 1953. In April 1954 the Smitty section was placed in production at a rate averaging 100 tons per day, thereupon becoming the first privately owned post-war uranium producer in Canada. The ore is shipped for processing 12 miles by truck to the mill of Eldorado Mining and Refining Limited.Until recently all of the Company's production was drawn from the Smitty orebody. In April, 1955, ore production commenced from the faulted west extension of the Smitty structure, known as the Rix 62 zone, and from the Leonard No. 1 vein.The Smitty orebody (see Figure 2) is an intensely brecciated lenticular zone bordering both sides of the Smitty fault. The breccia areas are irregularly mineralized with pitchblende, very sparse galena, and pyrite in a gangue of feldspar, chlorite, calcite, and silica, all thoroughly soaked with fine-grained hematite to produce the locally-called ""red alteration"".Tenor of the ore currently being mined is classified information. The average grade estimated, prior to production, was 0.20 per cent (4.0 lbs.) U308 per ton."

Jan 1, 1949

By A. G. Scobie

THE research laboratory of this Company was recently faced with the problem of determining trace amounts of tungsten in a series of classifier sands. A spectrographie survey revealed the feasibility of using this instrument in the final evaluation, but a check of the common methods in use for the isolation of tungsten (3, 4) showed these methods to give incomplete separation for trace amounts. An investigation into the possibility of modifying these procedures, or developing others, was thus indicated. ASSAY PROCEDURE Weigh 10 grams of 200-mesh ore or concentrate into a 400-ml. beaker, wet the sample well with about 20 ml. of water, and add 100 ml. of hydrochloric acid. Cover, digest at 60° to 70° C. for about 1 hour, and then boil down to approximately 25 ml. Cool, add 25 ml. of hydrochloric acid and 10 ml. of nitric acid, and again boil to former volume. Add 20-ml. portions of nitric acid with successive boiling clown until chemical action is complete. Then add 20-ml. portions of hydrochloric acid until all nitric acid is removed. Take nearly to dryness on a law-temperature hot plate, but do not bake. Take up in 10 ml. of hydrochloric acid and 20 ml. of water and heat on a law-temperature hot plate until all iron goes into solution. Dilute to 200 ml. and heat to just below boiling. Stir in pulp of about half of a No. 41 Whatman filter paper (12.5-cm.) and continue digestion on plate with occasional stirring for 15 to 20 minutes.

Jan 1, 1943

By S. Parkash, A. J. Szladow

Vigorous agitation of suspensions of coking coals in water (or light mineral oils) will often result in catast rophic loss of caking properties. It is shown that this deterioration is not a consequence of oxidation of the coals (by dissolved oxygen), but that it can be qualitatively connected with internal "solid-state" reactions which appear to derive their activation energies from cavitation of the liquid.

Jan 1, 1971

By G. S. Hume

"THERE HAS BEEN a marked growth in the petroleum industry in Canada since the end of the war. The rate of growth in the demand for oil products has exceeded that in United States, although the per capita consumption is still less. Estimates of the consumption of petroleum and petroleum products in Canada in 1951 are approximately 154,000,000 barrels, which is slightly more than 11 •barrels per capita, whereas the estimated consumption in United States for the same period, according to World Petroleum, is placed at 2,619,- 970,000 barrels. This, on the basis of a population of 154,000,000, would be equivalent to 17 barrels per capita. The increase in consumption of the petroleum and products is world wide. World production in 1951 has been estimated (Oil and Gas Journal) at 11,700,000 barrels a day or more than 41;4, billion barrels for the year. United States production increased 13.7 per cent to 6,143,000 •barrels a day and Canada'.s ,, total production increased about 65 per cent from a total of 29,091,235 •barrels in 1950 to an estimated (Dominion Bureau of Statistics) 48,096,800 barrels in 1951.The trend to use increased amounts of petroleum and petroleum products, particularly in the United States and Canada, has also been supplemented by increased use of natural gas. The rate of expansion of the consumption of natural gas in United States in the past few years has been very rapid, increasing from 2,600 billion cubic feet in 1940 to 5,975 billion in 1950, with the proven reserves in the same period increasing from 85,000 billion to 186,000 billion cubic feet."

Jan 1, 1952

By Dan Zou, Ji Chen, Deqian Li

"Bayan Obo mixed RE concentrate is the largest RE source in the world. RE elements occur dominantly in bastnaesite and monazite. This paper describes a clean and green technique for processing Bayan Obo mixed rare earth (RE) concentrate. A two-step oxidation method can lead to the effective recovery of REs, thorium (Th), fluorine (F) and phosphorus (P). Ce has a property of valency change, enabling the separation of it from other RE(III) elements. Making use of the interactions of cerium (IV) (Ce(IV)), F and P, a new extraction system was created to separate Ce(IV) effectively from other RE(III) while recovering F, P and Th by complexing F and P following the oxidation of Ce(III) to Ce(IV). The method includes two parts. Firstly, bastnaesite is oxidized by air roasting and sulfuric acid leaching. And then a first leach liquor containing Ce(IV), F and P is obtained. Secondly, monazite was converted into REhydroxide through alkaline attack and then Ce(III) in the RE-hydroxide was oxidized into Ce(IV) by wetair oxidation. After sulfuric acid leaching the oxidized RE-hydroxide, a second leach liquor is obtained. The two parts of leach liquor containing Ce(IV), F and P are then extracted by Cyanex923 to obtain CeO2, CeF3 and CePO4 based on the complex of Ce(IV) with F and P. The raffinate was further extracted by the primary amine N1923, and Th-product was recovered as ThO2. The RE elements recovery yield during the whole process is greater than 92%. The new technique not only provides a new way for Bayan Obo RE ore utilization, but also avoids resource waste and environment pollution.INTRODUCTIONRare Earths (REs) refer to lanthanides, including scandium and yttrium. Owing to the similar structure and property of RE(III), it is difficult to separate them from each other, especially for the adjacent elements. According to the United States Geological Survey, in 2010, the whole world has about 142 million tonnes of rare earth reserves. In that, China ranks the second with 22% following Brazil which ranks first with 32% (Cheng, 2011). There are three main RE ore types in China with about 80% mixed ores in Bayan Obo, 10% bastnaesite ores in SiChuan and ShanDong province and 2.9% ion adsorption ores in Southern China. Bayan Obo mixed RE concentrate consists of bastnaesite and monazite. The concentrate contains CeO2/_REO of 50% and there are 7–8% F, 4-6% P and 0.2–0.3% Th."

Jan 1, 2016

By Warnett Kennedy

"GENUINE CONCERN for the environment is a built-in attitude of mind. If you do not have it by age 40 you probably never will. Some people speak the jargon of 'environment' and 'ecology' for political reasons, others because it feeds their need and bias toward attitudes of moral indignation or dissent. Others pay lip-service for purely business reasons. Complete reactionaries equate conservationists, ecologists and environmentalists as either 'commies' or 'pinkos'. Their real credo is the old saying, ""Where there's muck there's brass."" Those who have genuine concern for good environment are not only romantics like Thoreau but realists who sense the danger to our planet if human greed is rampant and unchallenged. The cities are in real trouble. Almost 75 per cent of the population already live in and around cities. Even mining men live in cities or bring up their children in the new 'instant' towns. The ecology of cities is the concern of all. Our distinguished guest Stewart Udall, in his book ""The-Quiet Crisis,"" quoted Thoreau in 1859 as having written ""each town should have a miniature wilderness park, a primitive forest of five hundred or a thousand acres where a stick should never be cut for fuel, a common possession forever."" Mr. Udall will be glad to know that this advice was taken in at least one instance known to me. I refer to Stanley Park in Vancouver. It is a primitive forest of 1000 acres right inside our small downtown peninsula. It remains unmanicured. This month we celebrated the completion of a seawall of 4%, miles along its perimeter. The construction of this wonderful walkway started in 1910. We are very, very proud of our park."

Jan 1, 1972

By R. A. Sullivan

I T IS one of the unwritten policies at Preston Mines that we examine closely any method or tool that will help us in our constant battle against rising costs. It is our personal conviction that most work methods can be improved. Therefore even though the job went well yesterday, it does not necessarily follow that it should be done by the same method today. With the arrival of the natural gas pipe line in the Porcupine area it was obvious that we would have to take a good look at the possibilities of using this source of fuel for plant heating. • Steam presently generated at Preston is for heating purposes only, no process steam being required. Prior to the fall of 1960, the heating plant consisted of two low pressure, coal-fired, fire-tube boilers, operating at an approximate pressure of 14 pounds per square inch. These boilers were underfed by stokers and could be operated either singly or together. ~o. 1 unit was a horizontal return tubular boiler, registered at 100 h.p. No. 2 unit was a fire-box boiler, registered at 75 h.p.

Jan 1, 1962

By D. P. Fenton

The Phelps Dodge El Paso Rod Mill produces approximately 2.4 million pounds per day of copper rod from a casting and rolling operation. The newly formed rod is treated to remove mill scale and oxides using a sulfuric acid and hydrogen peroxide solution which is bled periodically when the copper concentration reaches 30-35 g/L. The bleed solution is heated to 75° C to destroy the residual peroxide. Copper is then recovered in a 270 cell EMEW electrowinning plant. Clean acid is also regenerated in the EMEW plant and is returned to the rod cleaning circuit. The EMEW plant commissioned in January 2006, has two operators and replaces a copper sulfate plant with fourteen operators. The EMEW plant has a capacity of 1700 kg/day of cathode copper at 2.1 kWh/kg copper deposited. The electrowinning plant operates in closed circuit with the rod mill returning up to 2600 kg/day of sulfuric acid resulting in zero discharge. Use of dimensionally stable anodes (DSA®) ensures that the acid quality is maintained in the closed loop operation. The operating conditions, performance and plant experience of the EMEW copper and acid recovery plant are discussed.

Jan 1, 2007

By Yosuke Ota, Makoto Tawara, Tetsuya Kojima

"Dry-lube has been used in Europe to enhance formability of aluminum sheet for automotive applications, but it is difficult to ensure degreasing performance with lower degreasing bath temperature. However, newly developed, highly lubricating pre-coats utilizing a urethane resin, which is soluble in water, have been found to show excellent degreasing performance. Furthermore, a richer pre-coat weight coincides with a lower friction coefficient and better formability. Combined use of anti-rust liquid oil showed different friction coefficient depending on applied surface pressure.INTRODUCTION The global demand for aluminum alloy products, especially for automotive application, has been increasing because aluminum alloys can offer excellent corrosion resistance with good strength and low density compared with steel. Aluminum alloys can contribute to saving much more energy and greenhouse gas emissions over the lifetime of the product. On the other hand, the amount of aluminum alloys in vehicle architectures is still somewhat limited due to relatively low formability. As a consequence of this low formability, it is necessary to set a certain limit to the shape of an aluminum alloy panel for automotive applications. So far hot melt wax dry lubricants have been in use especially in Europe as they have been recognized to provide better lubrication than conventional rust protection oils (Meiler & Jaschke, 2005). The benefit of hot-melt wax for automotive manufacturing is associated with a more stable forming process and the possibility to avoid extra lubrication in the press shop. But because of the low poorer solubility of hot-melt wax in degreasing aqueous bath solution, a higher degreasing temperature is required so that no remnant of hot melt wax can be carried over to the next manufacturing process. This temperature control is difficult to impress upon a manufacturing degreasing bath originally designed for liquid oil, especially in Japan. The typical temperature of degreasing bath in Europe is around 60°C, while it is only around 40°C. in Japan. Various types of pre-coats other than hot-melt with high lubricity have been reported (Tawara, 1993; Ueda, Hatsuno & Totani, 2013), but a balance between sufficient degreasing performance and high lubricity has not yet been achieved for an actual production process line."

Jan 1, 2018

By Larry B. Smith

"Feasibility studies are the means by which mineral reserves are established prior to financing a project. However, guidelines are generally lacking for the content, data quality and accuracy of these studies. Regulators take a principle-based rather than prescriptive approach to the content of studies and look to the industry to define study content. Professional organizations, engineering firms and mining companies must eventually establish guidelines and best practices for this work. Most likely these will draw on standards or “stage gates” that have been developed by major mining houses and engineering firms. Engineering studies must: 1.,Define optimal mining and processing methods, production rates, infrastructure, product sales, environmental management and risk mitigation. 2.,Increase confidence in resources, reserves, production plans, processing performance, infrastructure design, environmental management, permitting, capital and operating costs, and financial performance to support financing. 3.,Provide engineering designs suitable for accurate cost estimates. 4.,Develop project execution plans with sufficient confidence that project delays and cost overruns will not occur. Conceptual (scoping, preliminary assessment) Establish the principal characteristics of the project from the geology, resources, metallurgy and development constraints. Assess different approaches to mining and processing. Identify project execution requirements. Test project viability with economic analyses. Recommend additional work to increase the confidence in geology, resources, metallurgical performance, infrastructure, operating and capital costs, environmental conditions and permitting to allow selection of the best development options."

Jan 1, 2003

By G Zahary

THE most acceptable approacl1 to analyzing rock behaviour, at the present time, is based on the application of principles of mechanics and strength of materials. Analyses have been made in which the criterion of failure is based on maximum stress (1) and on Mohr's rupture theory (2). If such analyses are to be carried out, the mechanical properties of the rock must be known within acceptable limits. Although an adequate correlation of laboratory test results with field conditions has not been established, test results have been published (3) on the basis of their comparative value. That is, test results may be useful for comparing the behaviour of different rocks under similar loading conditions or of a particular rock under different loading conditions. This study aims at establishing some of the mechanical properties of an andesite rock by testing specimens cut _from diamond drill core. Drill core (EX) was provided from run-of-mine drilling by New Dickenson Mines Ltd. and Campbell Red Lake Mines Ltd.

Jan 1, 1963

By R. Gutray, J. E. Grainger

This paper deals with the use of a cement-deslimed mill tailings mixture for a scraping floor in cut-and-fill stopes at Madsen Red Lake Gold Mines Limited. It describes the mixing and placing procedures and the precautions used with respect to the floor while mining in the stopes. Details of the mix are presented, and advantages and disadvantages discussed. The paper concludes with a brief outline of the costs.

Jan 1, 1966

By G. F. Warning

"THE H. B. Mine is situated on the north side of Sheep Creek valley, about six miles southeast of Salmo, B.C. It is the most northerly producer along a belt containing a number of zinc-lead deposits, including the Jersey mine of Canadian Exploration Limited, 3 miles to the south, and the Reeves MacDonald mine, 12 miles to the southwest. The important zinc-lead producing area around Metaline Falls, Washington, lies 23 miles to the south. Two prospectors, Horton and Benson, located and staked the oxidized outcrops in 1.907. The property was named the H.B. after the two discoverers. Exploration by a number of operators failed to locate any sulphide orebodies until 1946, when Cominco began a geological study followed by surface drilling which was successful in locating extensive sulphide mineralization. A program of underground exploration revealed sufficient ore to war-rant mill construction. A 1 ,000-ton mill was completed by 1953, but due to low metal prices production was deferred until May, 1955. To September 1, 1959, 1,900,000 tons of zinc-lead ore have been milled; present milling rate is about 1,250 tons per day. Concentrates are trucked to the Trail Smelter, a distance of 35 miles."

Jan 1, 1960

By H. Huang, R. N. Gow

Acidic treatment of enargite (Cu3AsS4) dissolves both arsenic and copper from the mineral and then attempts to separate them in the leach solution. The reactivity of enargite was examined in acidic to neutral solutions, over the pH range 1-7, to determine a potential range for co-dissolution. Enargite mineral samples from Butte, MT and Quirivilca, Peru were used as working electrodes in a cyclic voltammetry corrosion cell setup, which were then cycled multiple times over -1000 to 1000 mV. Surface reactions and transitions were characterized using in-situ Raman spectroscopy, which were then compared to updated EH-pH diagrams for the copper-arsenic-sulfur-water system from a previous study done under alkaline conditions. The region of co-dissolution is limited to > 600 mV vs. SHE and pH < 1 under the proposed diagram.

Jan 1, 2014

By C. Jewell, G. H. Rupay

"67 - 2:15-3:00Regeneration of Hydrochloric Acid from Waste Pickle Liquor Using a Fluidized Bed Reactor System. G. H. RUPAY and C. JEWELL, Dominion Foundries and Steel Ltd., Hamilton, Ont.The disposal of acidic waste liquors from pickling processes has always been a problem for the steel industry. With increased awareness toward environmental control and the problems acidic wastes create, processes utilizing recovery and regeneration of the waste acids are becoming more popular. This paper describes the Keramchemie/Lurgi process for regenerating hydrochloric acid from waste pickle liquor using a fluidized bed reactor system. The process parameters are outlined, together with a brief description of the equipment. This is followed by a discussion of the operating problems and concludes with economic data."

Jan 1, 2000

By T. M. Waterland

A GREAT deal of work has been done at Britannia during the past three years in improving and standardizing rounds for development headings, and the results obtained have been very gratifying. The round which has recently been adopted as a standard for all drifts and cross-cuts has, in some instances, doubled the average length of break formerly obtained. It has also increased the footage of advance per labour shift and reduced explosives&apos; consumption. At the present time, with a shortage of skilled labour, more control is necessar7 in directing the drilling of rounds. The use of a standard round has been o great assistance to the foremen and shiftbosses. NATURE OF GROUND Most of the ground encountered consists of a moderately silicified chlorite schist, known locally as G.M.S (green-mottled schist). It cannot be termed hard ground, because a three and one-half inch Leyner will drill at an average rate of twelve inches per minute. Due to the abrasive nature of the ground, the gauge of the steel wears rapidly and in most cases one set of steel is needed for each hole. The ground is not &apos;free breaking and holes must be spaced correctly to obtain a maximum break. DEVELOPMENT OF STANDARD ROUND FOR THREE-SHIFT OPERATION Late in 1940, a development programme was started involving 7,000 feet of drifting, 6 ft. By 7 1/2 ft. In cross-section, in two headings. Plans were drawn up to advance the headings on three shifts. Equipment used in the headings was as follows: D.A.35 Leyner?machines, Eimco Model 12B mucking machines, nine one-ton end-dump cars, one Mancha Little Trammer on the longest heading, 20-pound rail, 4-in. 15 compressed-air line, 15-in. Fan pipe connected to 5 h. P. Coppus fan. Diamond-drill cross-cuts, 16 feet in length, were cut every 250 feet. Switches were installed at these cross-cuts and they served as passing points for the cars. One siding seventy feet in length was cut in each heading at approximately the half-way point. The cycle of operations planned was to muck out, drill, and blast each shift. Previous performance in this type of ground indicated that a daily advance of 12 feet to 14 feet might be made. However, if a better type of round could be developed, an increased daily advance would be possible. A study of the time available for each operation in a net working shift of six and one-half hours indicated that the maximum depth of round that could be mucked, drilled, and blasted each shift would be six and one-half feet. When this maximum depth was decided upon, the next problem was to develop a satisfactory round. Due to ventilation difficulties and to the short net working shift, the whole round had to be blasted at one time. In other words, no blasting of the cut-holes could be done.

Jan 1, 1942

By A. F. Matheson

"Bankfield Consolidated Mines, Limited, and Tombill Gold Mines, Limited, in the Little Long Lac area, Ontario, mined an orebody that was common to both. The discovery' of this orebody was made by surface prospecting in May, 1932, on Bankfield ground, following an original discovery made in the same manner on the same property on a small reef in Magnet lake in October, 1931. The production from the two mines between 1937 and 1942 was approximately 135,000 oz. gold from about 420,000 tons of ore, an average grade of 0.32 oz. a ton. Production was nearly equally divided between the two properties. Both mines are now closed, the ore exhausted.""The ore is mainly sheared and fractured greywacke and porphyry impregnated by silica and small amounts of metallic minerals. To a lesser extent there are definite quartz veins in the ore zone""(l). The metallic minerals present were principally pyrite, arsenopyrite, pyrrhotite, and native gold .As at other mines in the Little Long Lac area, an elongated, broad, deep trough of folded, steeply dipping volcanic and sedimentary rocks, striking roughly east-west and surrounded by younger granite, is host to the orebodies of the Bankfield and Tombill. In the immediate area of the two mines iron formation and conglomerate bands occur nearby both north and south of an intrusion of porphyry-Cliorite, suggesting repetition of beds and folding. Although considerable drag folding is in evidence, folding on the above scale has neither been proved nor disproved."

Jan 1, 1954