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By J. A. Finch, G. Labonté

"A long-standing objective has been to obtain interpretable measurements of the oxidation-reduction potential in mineral slurries. For this purpose several sensing electrodes (black platinum wire, platinum foil and spiral, gold foil and spiral, and sulphide minerals such as chalcopyrite and galena) were investigated to determine their response to the presence of sulphide minerals in the pulp, and to the addition of reagents commonly used in flotation. The observed discrepancies between the electrodes may be explained using a combination of the classical mixed potential model for complex solutions and the probability of contact between the mineral particles and the sensing electrode. It is shown from laboratory testwork that gold spirals are preferred over platinum electrodes. Finally, some of the practical aspects of using the electrochemical measurements in a plant environment are discussed.IntroductonThe interpretation of flotation of sulphide minerals in terms of electrochemical (electron transfer) processes has brought new possibilities for process control of selective flotation. Investigations on massive and compacted particulate bed electrodes have shown that the flotation of a given mineral in the presence of a collector can be controlled by the potential induced on the mineral surface. Also, phenomena such as collector less (self-induced) flotation, activation by heavy metal ions, and natural selectivity sustained by galvanic coupling during flotation might also be controlled by electrochemical means.The technique for measuring electrochemical potential in slurries is an adaptation of that used for solutions. The measurement of the oxidation-reduction potential of a solution (ORP , Redox, Eh) is usually carried out by immersing a noble metal electrode (platinum, gold or silver) and a non-polarizable reference electrode: Standard Hydrogen Electrode (SHE), Standard Calomel Electrode (SCE), or silver/silver chloride (Ag/AgCl) in the solution. (The abbreviation Eh implies the SHE is the reference electrode.) The potential difference between the two electrodes is measured using a high impedance electrometer. ASTM standard D 1498-76 (revised 1981)(1) covers the practical details of such measurements; however, it does not deal with their meaning either in complex solutions or in mineral slurries ."

Jan 1, 1988

By O. A. Bascur

Several new hydrometallurgical plants have been built in the past years, new processes and equipment as well as advanced process control systems are being used to deal with the increasing requirements of safety, quality and production. Plant Information Management Systems are now being recognized as a key infrastructure component of the plant, giving the management, the operators, process engineers, finance, maintenance, and regulatory agencies an integrated view of the operation and providing the links for the (increasingly) multidisciplinary organization. This paper reviews several implementations of Plant Information Systems; real time performance management infrastructure examples are reviewed as a key component of business strategies, such as Mine to Port Planning and Supervision, Metallurgical Mass Balances, Solvent Extraction Composition Statistical Process Control, methods to minimize organic losses, reduce variable costs and to improve metal extraction. Several examples are provided to illustrate how companies are using the real time and historical information from assets and metallurgical processes to enable and empower people to improve the operations quality, safety and throughput, as well as continuous improvement and innovation initiatives.

Jan 1, 2007

"The application of telerobotics to mining is currently being introduced into production systems around the world. Mining companies in Canada, Sweden, South Africa, and Australia have tended to lead the international charge to this form of technology for mining. While this introduction is taking place, a few basic questions have yet to be answered. How many machines can a single operator run? How many types of machines can a single operator run?A Canadian Research Chair in Robotics and Mine Automation has been established at Laurentian University to investigate these questions and many more through a series of experiments in a telerobotics laboratory that connects Laurentian teleoperation workstations to model mining machines at Cambrian College’s eDome. The laboratory supports many experiments allowing researchers to physically run multiple robot scenarios differing the numbers and types of machines at one quarter scale. Further experiments are being designed to investigate the potential for managing time delays in telerobotics. This paper describes the laboratory, experiments, and some preliminary results."

Jan 1, 2005

By G. R. Elliott

Foreword The office of the Supervisory Mining Engineer, a branch of the l. Federal Government, is financially interested in no oil company and has no stock to sell. This office, however, is deeply interested in the proper and efficient development of Canada's natural resources. The people of Canada are interested in the petroleum development in Turner Valley for two principal reasons: As represented by the Department of the Interior, they are the largest owners of petroleum and natural-gas rights in the field; As a nation, they are vitally interested in the development of petroleum and natural gas as a national asset, and therefore, also, in all productive property, no matter who directly controls the leases. As has been stated by Mr. Charles C. Ross, Supervisory Mining Engineer, "The Department, being responsible for the administration of these public resources, necessarily requires regulations to protect them from abuse by lessees. Our portion of this responsibility is to record a complete history of all drilling operations and to see that proper drilling methods are adopted to prevent damage and wanton waste of the valuable natural resources under discussion." Not only does our position necessitate an impartial and a judicial viewpoint, but, being day by day in touch with all operations in the western provinces, we are uniquely situated to comprehend both individual and general problems.

Jan 1, 1930

By George K. Foster

The Jeffrey mine of the Canadian Johns-Manville Co., Limited, is in the town of Asbestos, situated approximately 100 miles northeast of Montreal and about the same distance southwest of Quebec, in Richmond county, Quebec. Mining operations were started in 1881 on outcrops on a hill, as a side-hill cut, followed by a second and third cut. This development was the forerunner of the present large open-pit operations, the mine now ranking as the largest open-pit asbestos mine in the world. Operations were first carried on by hand, then by horsepower and later by stem cableways. By 1914, the derrick spans, 2,000 feet or more long, became unwieldy. To overcome this, and also to eliminate hand labour as much as possible, steam shovels and railway haulage were introduced. The steam shovels were replaced in 1928 by larger electric shovels of the full-revolving type.

Jan 1, 1946

By M. Vaccarini

In this paper a possible methodology to supplement a predictive control approach is reported. The benefits deriving from the application of a predictive control on complex buildings lay on its capability of adapting in advance to the conditioning needs of indoor environments. In fact, the mere reactive control is usually affected by response delays, mainly determined by latency intrinsic in systems and by the massive nature of buildings, which slows down their response to changeable inputs. Hence, systems are too often solicited at their maximum power to recover against comfort deficiencies, and high consumptions are had. This paper reports on the application of a predictive approach to the Passeig de Gracia (PdG) metro station in Barcelona, which is a considerably high energy demanding building and where ventilation systems are used to control both comfort and air quality. Although an extensive simulation for estimating energy savings obtainable through that approach is currently ongoing, in this paper we detail the several components which make up a ?predictive control framework? and we perform a preliminary demonstrative simulation. In particular, the whole setup is formed by: a detailed model of PdG, which simulates the station?s ?real state?; a control model, which optimizes a given cost-function; probabilistic predictive models to infer the future state of the systems, given the assumptions on the control actions by the control module. The outcomes of this paper show that the procedure is applicable and preliminary results over a short simulation horizon of half a day are reported.

Aug 1, 2013

By Patrick J. Williams

Defining Features of IOCGs ? Sulphur-poor Cu-Au(-Fe) deposits ? Contain low-Ti iron oxides ? Hydrothermal origin (breccia, vein, replacement) ? Local structural controls (no ?causitive? intrusions) Common Features (Economically-Significant Terranes) ? Regional space-time association with plutons ? Association with widely metasomatized crust ? Na ? Na-Ca ? K ? Variable enrichment in F, Co, Ba, LREE, U ? Little hydrothermal quartz (cf. porphyry deposits)

May 1, 2006

By J. H. Parliament

"The 15,000-tpd Similkameen open-pit copper mine, 10 miles south of Princeton, B.C., started production during 1972. The two main ore zones are separated by the deep canyon of the Similkameen River, with the Ingerbelle or western deposit being mined first. The location, design and construction of the plant were complicated by the steep terrain and the situation of the orebodies. Mining, utilizing 10-cu.yd electric shovels and 100-ton electric-wheel trucks, is conventional. Closely integrated with the preproduction mining was the construction of a 4-mile section of main highway to bypass the Ingerbelle pit. This entailed a very large fill, placed with mine equipment. Ore is crushed to minus 9 inches, stockpiled and reclaimed for direct delivery to three 32-ft-diameter by 14• ft single-stage autogenous grinding mills, each driven by two 4000-hp motors. Because of the friable ore in the upper part of the mine, 4-inch balls are added, with higher than design throughput attained. Classification is by 91>-inch spiral classifiers and cyclones. The flotation section comprises three parallel lines of ten 400-cu.ft rougher- scavenger cells and a single line of 100-cu.ft cleaner and recleaner cells. Concentrate is transported in end dump, closed trucks to Vancouver for dockside storage prior to shipment to the smelter. Tailings are piped across the canyon on a suspension bridge and through a tunnel to an empoundment area. Water is reclaimed and returned to the concentrator, forming a closed system. Dams are raised with cycloned ands, with the downstream section compacted."

Jan 1, 1973

By D. M. Doyle, P. J. Hannon

"The Canada/Nova Scotia Mineral Development Agreement (M.D.A.) is a subsidiary of a five-year Economic and Regional Development Agreement, signed on June 11, 1984. The objectives of the M.D.A. are to strengthen and diversify the Nova Scotian mineral industry and to coordinate federal and provincial policies and programs. The agreement outlines the activities and responsibilities of each government, including the division of the cost (60:40, federal: provincial) between governments. The agreement established a framework for joint planning to avoid overlap or duplication of programs.The M.D.A. programs are broadly divided into five sectors (Table 1 and Fig. 1): Geoscience, Minerals Technology, Development, Firm Specific and Public Information. Each sector is administered by a subcommittee composed of one federal member and one provincial member. The subcommittees report to a Management Committee. The Canada/Nova Scotia Mineral Development Agreement (M.D.A.) Management Committee is made up of Dr. Jack Reeves from EMR and Dr. Richard Potter from the NSDME.The Geoscience subcommittee, co-chaired by Peter Giles (NSDME) and William Poole (EMR), manages the regional geologic, geochemical and geophysical studies in the province. Included in this sector are studies into mineral deposits and the basic geological relationships between mineral deposits.The Mineral Technology sector is co-chaired by the authors, Don Doyle (CANMET) and Pat Hannon (NSDME). This sector of the M.D.A. conducts studies into mineral processing, sampling, deposit byproduct commodities and project feasibility analysis."

Jan 1, 1987

By E. Lovera

ABSTRACT: The current study analyzes the feasibility of an odd operation: to obtain, using a properly tailored drilling and blasting scheme, blocks suitable for the production of dimension stone from tunnel driving. Clearly, a compromise must be found between the rate of progression and the achievement of workable blocks. As a case study, a civil work under consideration in northern Italy was examined. The work was planned to cross a conglomerate that has traditionally been locally exploited for the production of highly prized paving and lining stones with excellent strength and aesthetic features. Natural exposures and mined-out quarries were available for tests. The relevant rock data are given, blast designs are shown (within the limitations of contour accuracy), and the test program is described.

Jan 1, 2011

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 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 Peter A. Hacquebard

"The coals of the Sydney and Pictou coalfields are generally classed as high volatile ""A "" and medium volatile bituminous coals but there are significant differences within and even beyond this rank. These are related to the observation that the coalification in eastern Canada is essentially post-deformational, resulting in a general increase of rank with depth in individual seams.Exploration drilling in the Sydney coalfield has shown that the rank increases offshore to M. V. bituminous at mineable depths and in the Pictou field to L. V. bituminous coal. There is also a marked easterly shift in rank within one seam at the same depth at Sydney, with the result that M. V. coal will be reached sooner in the Donkin Reserve area (at 700 m depth) than in the Lingan-No , 26 Reserve area (at 900 m depth). These rank changes are important for the manufacturing of metallurgical coke as shown with coke stability predictions based on petrographic analyses. The L. V. coal of the Pictou field can be used for blending purposes and is the only known L. V. deposit of mineable thickness in eastern Canada.In addition, the vertical rank changes between seams have been studied in ten boreholes. They are not constant within the confines of the Sydney coalfield. Four separate areas can be recognized, each with different coalification gradients, which can be related to changes in the paleogeothermal gradients . Variations of 2.5 degrees to 6. 7 degrees CI IOO m are indicated and geological causes for these changes are suggested.IntroductionThe Sydney coalfield is the largest and most important field in eastern Can ad a, and although it has been in production some 200 years, the remaining ""demonstrated "" resources of 1.6 billion metric tons can extend its production capability for at least another 100 years. All coals mined are high volatile "" A"" bituminous and have been used for both thermal and metallurgical purposes. For the latter rank variations even of a minor scale are of critical importance for the manufacturing of metallurgical coke.The significance at the present time of the Pictou coalfield, which has only modest remaining "" demonstrated"" resources of 60 million metric ton s, lies in the discovery in 1975 of a 14-million-ton deposit of low volatile bituminous coal. It is the only known low-volatile coal in eastern Canada and is suitable for use as a blend for metallurgical coal. As such, it could supply the Sydney coke ovens for a period of 30 years at the current rate o f coke production and replace imported American low volatile coal.Consequently, coal rank studies of the Sydney and Pictou fields are important not only from a geological point of view, but also because of economic considerations."

Jan 1, 1984

"NI 43-101 is a rule that governs how issuers disclose scientific and technical information about mineral projects to the public in Canada. The disclosure standards apply to oral statements as well as written documents and websites. NI 43-101 does not apply to disclosure concerning petroleum, natural gas, bituminous sands or shales, groundwater, or coal be methane. NI 43-101 first came into force on Feb. 1, 2001 and was revised in December 30, 2005. As a “National Instrument”, the law has been passed in each provincial and territorial legislature across Canada.“PART 1 DEFINITIONS AND INTERPRETATION 1.1 Definitions - In this Instrument “adjacent property” means a property(a) in which the issuer does not have an interest;(b) that has a boundary reasonablyproximate to the propertybeing reported on; and (c) that has geological characteristics similar to those of the property being reported on; “data verification” means the process of confirming that data has been generated withproper procedures, has been accurately transcribed from the original source and is suitable to be used; “development property” means a property that is being prepared for mineral production and for which economic viability has been demonstrated by a feasibility study; “disclosure” means any oralstatement orwritten disclosure made by oron behalf of an issuer and intended to be, orreasonablylikely to be, made available to the public in a jurisdiction of Canada, whether or not filed under securitieslegislation, but does not include written disclosure that is made available to the public only by reason of having been filed with a government or agencyof government pursuant to a requirement of lawother than securities legislation; “early stage exploration property” means a property that has(a) no current mineral resources or mineral reserves defined; and (b) no drilling or trenching proposed; in a technical report being filed in a local jurisdiction; “exploration information” means geological, geophysical, geochemical, sampling, drilling, trenching, analytical testing,assaying, mineralogical, metallurgical and other similar information concerning a particular property that is derived fromactivities undertaken to locate, investigate, define or delineate a mineral prospect or mineral deposit; “feasibility study” means a comprehensive studyof a mineral deposit in which all geological, engineering, legal,operating, economic, social, environmental and other relevant factors are considered in sufficient detail that it could reasonably serve as the basis for a final decision by a financial institution to finance the development of the deposit for mineral production; “historical estimate” means an estimate of mineral resources or mineral reserves prepared prior to February 1, 2001;“IMMM Reporting Code” means the classification system and definitions of mineral resources and mineral reservesapproved by The Institution of Materials, Minerals, and Mining in the United Kingdom, as amended; “JORC Code”means the Australasian Code for Reporting of Mineral Resources and Ore Reserves prepared by the Joint Ore Reserves Committee of the Australasian Institute of Mining and Metallurgy, Australian Institute ofGeoscientists and Mineral Council of Australia, as amended; “mineral project” means any exploration, development or production activity, including a royalty interest or similarinterest in these activities, in respect of diamonds, natural solid inorganic material, or natural solid fossilized organic material including base and precious metals, coal, and industrial minerals;"

Jan 1, 2003

By E. Fiset, T. Hennebel, F. Verbruggen, A. Prévoteau, K. Rabaey

Arsenic (As), bismuth (Bi) and antimony (Sb) are known to affect the quality of copper deposits in copper electrowinning operations. The codeposition of As was previously believed to occur only at current densities far exceeding the range of typical current densities for copper electrowinning. In this study, we investigate the copper electrodeposition on different pretreated stainless steel (SS) substrates from bleed electrolyte in galvanostatic mode at –45 mA/cm². Scanning electron microscopy (SEM) micrographs illustrate that during the initial phases of copper nucleation and growth, the current density was locally increased due to the pretreatments. It was reasoned that the codepostion of As could possibly occur in normal electrowinning conditions, but the risk can be substantially reduced by good SS substrate handling and maintenance practices. INTRODUCTION The presence of As, Bi and Sb is known to have a deleterious effect on the copper cathode quality in copper electrowinnings (Hiskey & Maeda, 2003; Hoffmann, 2004; Xiao, Cao, Shen, & Volinsky, 2012; Xiao, Cao, Mao, Shen, & Ren, 2014; Jafari et al., 2017). They are known to influence both the chemical and physical quality of the copper as they can contaminate the copper (Jafari et al., 2017) and affect the copper deposit structure (Hiskey & Maeda, 2003; Kim, Kim, & Chung, 2009), which contributes to a degraded market value of the copper (Tuddenham, 1984). The incorporation mechanisms of these impurities are believed to occur mainly through slime inclusion (F. Xiao et al, 2012) and electrolyte inclusion (Hiskey & Maeda, 2003). Other studies suggested that codeposition of these impurities is possible by their standard reduction potential being close to the one of copper (Xiao et al, 2014). Hiskey and Maeda (2003) investigated the copper electrodeposition on a copper electrode substrate in Cu electrolytes with a Cu, H2SO4, As, Bi, Sb composition representative for commercial copper tankhouses. The combination of voltammographic techniques and Auger electron spectroscopy showed that As was the first impurity to be electrodeposited from this electrolyte, yet at potentials where the limiting current density of the copper electrodeposition reaction is exceeded. The copper tankhouses usually operate at a current density ratio of 0.3 to the limiting current density in order to achieve tolerable copper quality deposits. The codeposition of As could be considered impossible in this current density condition. However, it is known that during the initial phases of electrodeposition on foreign substrates, a substantial part of the reaction proceeds by growth of individual nuclei where the current density is locally high and diffusion limited (Radisic, Ross, & Searson, 2006). Furthermore, it was observed that copper nucleation on TiO substrates occurred preferentially in the scratched oxide free areas which could serve as parts with high localized current densities (Chang, Choe, & Lee, 2005).

Jan 1, 2019

By A. Hutwalker, T. Plett

"Blast fumes are one of the major sources for NOx in underground mines. In 2016, the Occupational Exposure Limits for NOx in Germany were reduced by 90%. The task is to keep re-entry times after blasting at the present level and thereby ensure an economic operation of the mine. Measurements show that using ventilation solely is not sufficient. A new approach to reduce NOx from blast fumes is described. Laboratory experiments were performed and a reduction of NOx was observed. Measurements were conducted at an explosive factory’s testing facility and in an underground mine at blasting operations. INTRODUCTION Whether for production of ore or for drift development, the processes in an underground mine are always the same: 1) fracturing the rock, 2) loading the pile, 3) support the resulting cavity. The fracturing of the rock can be done mechanically, by cutting, for example by using continuous miners or tunnel boring machines, or by drilling and blasting. Drilling and blasting is more flexible than mechanical driving, as it can be used independently of the rock strength. Furthermore, this driving method allows a more flexible reaction to changes in geological and/or operational conditions. Thus, underground mining and blasting are almost inextricably linked with each other, and regardless of the size and level of technology of the mine, blasting is hardly avoidable. Depending on the mining method chosen and the existing framework conditions, such as the mechanical properties of the rock or the availability of machinery, blasting is an integral part of daily operations. Even in mines where blasting is not part of regular operations, it cannot be completely avoided. The blast fumes generated by the explosions are, in addition to diesel engine emissions, one of the two main sources of emissions of nitrous gases underground. Up to now, state of the art for dealing with blast fumes is ventilation. The fumes are diluted with fresh air and ventilated out of the mine. This treatment of blast fumes is more than sufficient with the former German Occupational Exposure Limits (OEL). The adaption of the OEL in Germany to the recommendations of the Committee on Occupational Exposure Limits (SCOEL), a committee of the European Commission, leads to big challenges for the mining industry in reducing the concentrations of these gases at the workplaces underground. On its meeting on May 2nd and 3rd 2016, the Committee on Hazardous Substances (Ausschuss für Gefahrstoffe, AGS), an advisory body of the German Federal Ministry of Labour and Social Affairs (BMAS), advised the BMAS to copy the OEL, as recommended by the SCOEL, to the Technical Rules for Hazardous Substances (TRGS 900). BMAS followed this advice, consequently the new OEL where published on November 4th 2016 and became part of the TRGS 900. Table 1 shows the former and new OEL for Germany. These new OEL became law after publishing, but two exceptions were made: For tunneling operations, they became law on October 31st 2017, for mining operations they will become law on October 31st 2021 (BAuA, 2004, 2016, 2017)."

Jan 1, 2019

By J. B. Heslop, D. S. Bubar

"The Gondor Zn-Ag-Pb-Cu deposit is a stratabound massive sulphide lens occurring within Archean volcaniclastic rocks of the Yellowknife Supergroup. The deposit is located in the west-central portion of the Slave Structural Province, approximately 350 km north of Yellowknife.Initial diamond drilling at Gondor has outlined a steeply dipping, L-shaped, folded, massive sulphide body, which may be traced over a strike length of approximately 800 m, and to a depth of 350 m. True widths of up to 40 m have been intersected in the thickest part of the deposit. Preliminary estimates suggest that the deposit contains a minimum of 7.5 million tonnes grading 6% Zn, 50 g/tonne Ag and less than I% combined Cu and Pb. In addition, significant gold, grading up to 2.8 g/tonne, occurs in some parts of the deposit. The mineralization is open both down-dip and along strike.The Gondor deposit lies conformably within a predominantly east-west striking, north-facing sequence of felsic to intermediate volcaniclastic rocks. Coarse fragmental rocks are abundant in the hanging wall, whereas ash and lapilli-tuffs predominate in the footwall. The main structural feature in the area is a large-scale, steeply northeast-plunging, Z-shaped fold. The sulphide mineralization lies within the synformal portion of this fold, with the thickest part of the deposit coinciding with its hinge zone. Several episodes of faulting have also affected the local stratigraphy.The wallrocks of the Gondor deposit were hydrothermally altered prior to the onset of medium-grade regional metamorphism. A halo of altered rocks surrounds the massive sulphide lens, with no apparent difference in the degree of alteration between the hanging wall and footwall strata. The alteration zone is characterized by the addition of MgO and K20 and by the depletion of Na20 and CaO. These changes are reflected in the mineralogy of the altered wallrocks by local enrichment in chlorite, biotite, muscovite and cordierite.The mineralized zone is medium- to coarse-grained, well-banded and is composed largely of pyrite, quartz, and sphalerite with subordinate galena and chalcopyrite. Preliminary studies of metal distribution indicate that a lateral zonation is present, with lead enrichment in the central part of the deposit, and copper enrichment toward both ends. Stringer-type copper mineralization has not yet been discovered in the footwall of the Gondor deposit."

Jan 1, 1985

"The Code was developed in 2004 through the Collaboration Agreement between Institution of Mining Engineers of Chile (IIMCh) and the Ministry of Mining (Chile) in Dec 2002. It is an amalgamation of current practices with respect to standards and procedures for exploration prospects, mineral resources, and reserves for the purpose of public reporting. Certification is required to prepare and issue information on mineral assets according to the guidelines that regulate the technical, economic, and environmental aspects that satisfy the conditions set by the Chilean capital and financial markets.The Mineral Resources Committee of the Instititution of Mining Engineers of Chile (IIMCh) is pleased to introduce theCode for the Certification of Exploration Prospects, Mineral Resources and Reserves which is the result of a Collaboration Agreement between the IIMCh and the Ministry of Mining established in December, 2002.This code synthetizes the present practice of the mining industry in regard to standards and procedures applied to exploration prospects, mineral resources, and reserves with the purpose of reporting publicly on financial instruments based on these mine assets in the capital markets. These standards follow general criteria already adopted and applied by capital markets in those countries characterized by a very dynamic and well developed mining sector such as Australia, Canada, Southafrica, United Kingdom, and others. The work done by the Mineral Resources Committee of the IIMCh has had the recognition of the Combined Reserves International Reporting Standards Committee (CRIRSCO) that leads the establishement of an international code in these matters. CRIRISCO is an entity formed by representatives of the countries previously mentioned, a representative of the Society of Mining Engineers of the UStates and a representative of the IIMCh. The Institution thanks the Ministry of Mining, the representatives of these Ministry in the Mineral Resources Committee, and specially the Minister of Mining, Sr. Alfonso Dulanto Rencoret due to the genuine support given to the IIMCh in the preparation of this Code.The Institution also thanks the Superintendencia de Valores y Seguros (SVS) because of the help given continuously to the Committee as well as by the interchange of opinions and suggestions received during the preparation of this document."

Jan 1, 2003

By R L. Cheesman

An extensive Precambrian iron-formation lies about 2,000 ft. beneath post-Precambrian rocks in the Fort a Ia Corne Forest Reserve, south of Choiceland, Saskatchewan. The geology, deduced from limited drill results and from some geophysical observations, indicates that the deposit is a characteristic magnetite iron-formation, not uncommon in the exposed Precambrian of Saskatchewan, but also shows certain interesting features of faulting and pre-Paleozoic weathering which have given rise to a pre-served detrital deposit of hematite. The body is of ore grade and of sizeable proportions. T HIS paper is presented in order to set forth the interesting geological features of a Precambrian iron deposit located beneath the cover rocks of the Great Plains region and to comment upon the methods of discovery and interpretation of the nature of the body. The Choiceland iron deposit is located in the Fort a Ia Corne Provincial Forest Reserve, some 15 miles south of the town of Choiceland, Saskatchewan. Choiceland is

Jan 1, 1964

By W. E. Roscoe

"Mineral exploration properties are those on which an economically viable mineral deposit has not yet been discovered. Such properties are bought, sold, optioned and joint ventured on the basis of their perceived potential for the existence and discovery of a viable mineral deposit. The intrinsic value of an exploration property is therefore based on the exploration potential. One measure of the exploration potential is the amount that can be justified to spend on exploration for a viable deposit.The appraised value method uses a cost approach to value exploration properties. It is based on the premise that an exploration property is worth the meaningful past exploration expenditures plus warranted future costs to test remaining exploration potential. Results of past exploration work are analyzed in order to retain only those past expenditures that are productive in terms of identifying remaining potential. Warranted future costs comprise a reasonable exploration budget to test that potential."

Jan 1, 2002