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By Erik Richer La Fleche

LEGAL RISKS LEGAL RISKS ARE COUNTRY RATHER THAN PROJECT RISKS OTHER COUNTRY RISKS ARE POLITICAL AND MACRO-ECONOMIC RISKS COUNTRY RISKS ARE EXAMINED AFTER PROJECT RISKS COUNTRY RISKS COUNTRY RISKS INCLUDE: WAR AND ARMED CONFLICT TERRORISM AND SABOTAGE CURRENCY INCONVERTIBILTY AND TRANSFER NATIONALIZATION AND CREEPING EXPROPRIATION GOVERNMENTAL BREACH AND REPUDIATION OF CONTRACT CHANGE OF GOVERNMENT CORRUPTION COUNTRY RISKS FIRST NATIONS AND LANDOWNER CLAIMS LABOUR UNREST SINGLE CAUSE ACTIVISTS REGULATORY AND BUREAUCRATIC DELAYS CONFLICT BETWEEN GOVERNMENT LEVELS ETHIC AND RELIGIOUS TENSIONS INTERNATIONAL SANCTIONS TAXATION CHANGES CHANGES IN LAW

May 1, 2013

By Richard F. Lynch, Frank E. Goodwin

"The development of Galfan, a new generation 95% zinc-5% aluminum-mischmetal alloy coating for steel, offers opportunities for greater fabrication flexibility and upgraded corrosion performance in automotive applications. The formability of Galfan is equivalent to that of electrogalvanized steel, based on laboratory tests and automotive component fabrication. Corrosion resistance of Galfan exceeds that of hot dip and electrogalvanized, including performance in automotive industry tests. Automotive production applications for deep drawn and stamped components in France and Germany are based on the ability to meet dual performance requirements for upgraded formability and corrosion resistance. The first U.S. Galfan application was on 1985 model Ford cars and light trucks for transmission oil cooler lines which has now expanded into a number of power steering tubing uses. IntroductionContinuing requirements for improved vehicle performance coupled with the ever present need for reduced cost have spawned the development of a number of new coated steel products. Among this new generation of coated steels is Gaifan™, a 95070 zinc-Solo aluminum-mischmetal hot dip alloy coating. Galfan exhibits particular promise for automotive use based on broad fabrication advantages and upgraded product performance(I ),The unique characteristic of Galfan is the key combination of greatly improved formability with much longer corrosion life. Galfan provides significantly better formability than any other hot dip coating. Testing shows that formability is limited primarily by the steel substrate to which the Galfan coating is applied. Galfan exhibits excellent resistance to flaking and microcracking during commercial forming operations. The result is the elimination of unnoticed damage to the coating which would show up later as premature rusting on the finished product."

Jan 1, 1987

By C. J. Coulson, G. A. McKay, A. M. Cormie

"The Leitch mine, in the Beardmore area, Thunder Bay district, Ontario, is a part of the Leitch estate. It includes a group of patented claims, staked by P. A. Leitch of Port Arthur early in the century, along bands of jasper, hematite, iron-bearing slates, carbonatized schists, and greywacke, commonly known as 'iron formation'. The folding and shearing in these variably interstratified beds is a striking structural feature. The vein pattern is very definitely related to these structures.ROCKSThe rocks in the area are typical Keewatin lavas-greenstone-overlain by a series of Timiskaming sediments consisting of arkosic greywacke, iron formation, slate, greywacke, conglomerate, and greywacke, in this order from the contact. The sedimentary beds are generally conformable with the older rock contact except on local folds.Small intrusions of diorite occur as nearly vertical dykes and are believed to be of Algoman age. To the northwest of the mine there are larger intrusions of granodiorite belonging to the same period.Several dykes of quartz diabase up to 100 feet in width, striking generally north and south, with a vertical dip, cross the property. These have been classified by W. C. Laird as pre-Keweenawan in age. One of these dykes in particular is of importance for it cuts through the No. 2 vein and serves as a pillar when stoping. It is approximately 6 feet wide.The youngest rock type represented is a sheet of olivine diabase that extends over an area of thousands of square miles in and around lake Nipigon. It underlies most of this area and its outcrops form some of the most interesting topographical features, with fault scarps rising hundreds of feet. In the vicinity of the mine shaft the sheet is about 600 feet thick and extends from a depth of 1,871 feet to approximately 2,470 feet. It has a dense, hard, chilled margin and a sharp, tight contact. It intruded the sediments with very little lateral disturbance. The chief effect was baking, which darkened and hardened the greywacke near the contact. The sheet dips flatly to the cast."

Jan 1, 1954

By Rick Wilkins

The stability of steep embankments is a major safety issue in open pit mining, highway passes, and earth filled dams. A failure in any one of these situations could mean a loss of very expensive equipment, a long term inconvenience, and more importantly, a loss of life. These possible catastrophes could be avoided by installing a reliable real time monitoring system. Robotic total stations (RTSs) give one possible cost effective solution to creating a near real time monitoring system. Repeated surveys at predetermined time intervals can automatically generate warnings if slope movements exceed a preset tolerance level. The variation in atmospheric refraction, combined with possible instabilities in reference targets, can make a monitoring system based on RTSs produce false alarms. A methodology has been developed at the Canadian Centre for Geodetic Engineering (CCGE) for reducing these systematic error effects. The methodology has been realized in the creation of a software package that has been successfully implemented at large earthen dams in California and at an open pit mine operation in British Columbia.

May 1, 2002

By L. Li

Iron removal is a common procedure in hydrometallurgy of non-ferrous metallic ores. Chemical precipitation and solvent extraction are currently the main methods employed for separation of iron from copper leach solution. However, chemical precipitation methods have the problem of producing large amounts of iron precipitates, and/or requiring high temperature and high pressure conditions for precipitation. The precipitates are difficult to separate from the solution. Emulsification is a general problem for solvent extraction, which causes loss of extractants and contamination of the electrolyte. A common problem for solvent extraction and chelating ion exchange processes is the difficult iron stripping process. Therefore, finding an efficient and environmentally friendly method for iron removal is of great significance. In this paper, new processes of using ion exchange resins to remove iron from copper leach solution have been investigated. Salicylic acid, amino carboxylic acid, amino phosphonic acid and hydroxy-oxime resins were employed to adsorb iron from a simulated copper leach solution containing 40 g/L of Cu2+ and 36 g/L of Fe3+. It was found that a hydroxy-oxime resin, named Z-Fe, has excellent adsorption selectivity on Fe3+. Desorption behavior of the resin was studied by two step elution using dilute H2SO4 and oxalic acid solution, respectively. After optimizing the adsorption-elution processes, the extent of removal of iron from the simulated copper leach solution using resin Z-Fe was 90%, while copper recovery could reach 100% in closed circuit processing.

Jan 1, 2016

By R. Simkus, J. K. Gowans

Polaris Operations, a Cominco Ltd. lead-zinc mine, is located on Little Cornwallis Island, Northwest Territories, at Latitude 75°23' N and Longitude 96°75' w. When the Polaris Mine went into operation in late 1981, it became the world's most northerly base metal mine.The Polaris Concentrator, housed in a unique process barge, is a basic lead-zinc concentrator where flotation is used to produce the lead and zinc concentrates.The paper describes the ""coarse lead"" flotation feature incorporated in the concentrator flowsheet and describes the start-up problems and continuing operation of this circuit.

Jan 1, 1984

By Alfred C. Lane

WE recently received from Professor A. C. Lane, Emeritus Professor of Geology and Mineralogy, Tufts College, Mass., and a Corresponding Member of this Institute, a very interesting account of some recent developments in radioactive methods of determining the age of minerals and, therefore, of the rocks in which they occur. It deals in particular with studies of the minerals of certain pegmatite dykes on the Huron claims and Bear claims in southeastern Manitoba, which, the results indicate, are among the oldest rocks of the earth's crust. The following article presents a non-mathematical summary of Professor Lane's paper . . It will be noted that he is anxious to obtain suitable samples of certain minerals and rocks for further age studies. We hope some o our members may be able to supply him with the material he needs. It may be well to explain briefly how the age determinations are made. Uranium is continually breaking down, or disintegrating in successive steps through radium, etc., to a final product which is lead (uranium-lead), and the rate at which this change takes place is known. Minerals containing uranium will therefore contain lead also, and the lead-uranium ratio mul-tiplied by a certain factor (approximately 7 ,600) will give the age of the mineral in millions of years. Thorium also disintegrates at a known rate to give lead (thorium-lead) as a final product, and the age of a mineral containing thorium can thus be calculated from the lead-thorium ratio. Thorium breaks down more slowly than uranium. In unit time, one gram of thorium produces about as much lead as 0.36 grams of uranium.-ED.

Jan 1, 1938

By T. D. Traubert, J. T. Dietz, D. Catena

"Canadian process industry experts have often observed the strong trend for U.S. industrial safety and environmental laws to creep across the border. These experts will be interested in new United States (OSHA) regulations (29 CFR 1910.119), and anticipated new U.S. Environmental Protection Agency (EPA) regulations that will require over 28 000 U.S. refineries and chemical plants employing more than three million workers, to begin a comprehensive Process Hazard Analysis (PHA) of these complex plants immediately. Impending EPA regulations are expected to expand these efforts and add process Hazard Frequency and process Hazard Consequence reviews for many additional industrial locations.These regulations were created to reduce catastrophic industrial accidents, and emergency releases of hazardous chemicals which endanger employees, the public, and the environment.Accurate, and field verified Piping and Instrument Diagrams (P&IDs) are essential to permit a meaningful Process Hazard Analysis or emission release to be done. Today accurate P&IDs often do not exist. Many companies that have started to update their old P&IDs have found the process to be far more difficult, time-consuming,and expensive than they ever thought.This paper describes a new technique of computer drawn ""Intelligent"" P&IDs that can make a Process Hazard Analysis less expensive, more accurate, easier to perform, and provides lasting benefits to the plant owner long after the PHA has been completed."

Jan 1, 1993

By Jianhong Xu, Hailong Hou, Yu Jing, Yundong Wang

Microcapsules containing extractants have been applied to the extraction of metal ions, organic acid, pesticide, and herbicide. The difficulties of conventional liquid-liquid extraction in phase mixing and phase separation (e.g. high energy consumption, emulsification phenomenon, and large equipment requiring housing) could be overcome in a liquid-solid system by using microcapsules. Even some extractants with high viscosity and poison can be encapsulated conveniently into microcapsules. In the work described in this paper, polysulfone microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (P507) were successfully prepared. Then, the extraction rate of lanthanum, samarium, and erbium in dilute solution into the microcapsules containing P507 was studied. An extraction kinetic model is proposed based on the interfacial reaction model accompanied by intraparticle diffusion expressed by Fick’s law. The extraction efficiency was obtained by using the kinetic model with the separately determined complex formation rate constant and the intraparticle diffusion coefficient. From the results, it was confirmed that the kinetic model could predict the experiment in a microcapsule system over a wide concentration range of lanthanide solution. In the future, the model could provide good guidance for the design and application in extraction of lanthanides.

Jan 1, 2014

By C. E. Cairnes

The Slocan mining camp in Kootenay district; British Columbia; has long been noted for the great number of its silver-bearing deposits; and for the success that has; in many instances; attended their development. The orebearing area lies east of Slocan lake and mainly within a radius of 6 to 8 miles of the mining town of Sandon. Within this limited area 135 or more properties have shipped ore in quantities of from 100 tons or less to more than 500; 000 tons; and with a total value in silver; lead; and zinc ranging from a few hundred dollars to well over $10; 000; 000. Of the three metals; silver has easily ranked first in value; with lead second and zinc third. Zinc production; however; made slow progress in the early years; and with . the exception of the Lucky Jim mine; and a few others where high-grade ore could be readily hand-sorted; was a detriment to the silver-lead ores until improved methods of separation enabled it to take an important place in the mineral production of the Slocan.

Jan 1, 1954

By Douglas W. Reeve, Hoc Nghia Tran, David Barham

"In kraft pulp mills, the spent pulping liquor is concentrated and used as fuel in the recovery boiler. Extensive deposits are formed in the upper section of the boiler due to the very high ash content of the fuel and the volatite nature of the ash. Deposits are composed of Na2S04, Na2C03 NaCI, some potassium salts and reduced sulphur compounds. Chloride and potassium salts are enriched in the deposits compared to the smelt due to their greater volatility.Severe corrosion of the superheater tubes in a recovery boiler has been traced to three factors: a non-uniform temperature profile in the flue gas, relatively high operating steam temperatures and high chIoride and potassium concentrations in the fireside deposits.The role of chIoride and potassium in superheater corrosion has been explained by increased Iiquid phase in deposits. Together with corrosion studies, this information has shown that kraft recovery boiler superheater corrosion due to the chloride and potassium enriched deposits can be avoided by proper boiler operation and by judicious superheater and furnace design.IntroductionThis investigation of recovery boiler superheater corrosion was initiated by the discovery of severe corrosion of the final stage superheater in a Canadian closed cycle kraft pulp mill(1,2). Metal wastage leading to tube failure was believed to be due to three major causes : the relatively high operating steam temperatures, the uneven distribution of flue gas temperature across the boiler which created a "" hot spot"" and the high chloride and potassium concentrations in the superheater fire side deposit. The mill responded to the problem by i) lowering the superheater steam temperature from 475°C to 380°C, ii) minimizing the chloride content in the spent pulping liquor, by controlling the NaCI input with recovered bleach plant effluent, and iii) changing metallurgy of a portion of the bottom section of the final stage superheater platens from ferritic steel T-22 (2.25% Cr, 1% Mo) to austenitic steel Incoloy 800H (21% Cr, 32% Ni, 46% Fe, 1.5% Mn, 1% Si, 0.6% Al) (Fig. 1). Details of the superheater corrosion experienced in the closed cycle mil! have been reported in previous papers(l ·2,) ."

Jan 1, 1984

By Dieter Birk

"The Atlantic Coal Institute illustrates the potential for high technology employment in Maritime Canada, by using local talent and the latest equipment to address a national market. Since I983, contract research for industry and government has generated 31 man-years of high-tech employment, added $2.3 million to the local economy and contributed new technology for Canadian coal. Industry now has access to new procedures for coal minerals analysis, pyrolysis, and geochemistry applied to industrial problems of exploration, beneficiation, conversion and combustion.Research at the Institute is market-driven, based on cost recoveries from contracts. The financial performance to date exceeds that of similar industrial research institutes in major cities and demonstrates that small isolated laboratories are cost-effective. Economic renewal of Canada's resource industries will require increased R&D which in turn can be a source of local employment and pride. Small research teams are more efficient but require an enlightened policy of contracting-out by big business and big government."

Jan 1, 1987

By A. Sacit Saydam

"Induced polarization/resistivity and magnetometer surveys have been carried out over the Casmo molybdenite deposit in mountainous terrain of northern British Columbia. Molybdenite occurs in quartz-bearing fractures with or without pyrite along a zone of hydrothermal alteration and intense fracturing, believed to be a northerly dipping fault zone, within medium-grained equigranular and porphyritic quartz monzonite.The molybdenite-bearing zone is characterized by a significant resistivity low, a metal factor high and a subtle IP low flanked by highs outside the mineralized area. Magnetic trends, indicated by a magnetometer survey, generally parallel the zone and strike direction of the different intrusive phases, and have been helpful in delineating contacts and faults in the area.IntroductionThe Casmo molybdenite deposit is 6 km southwest of the asbestos mining town of Cassiar in northern British Columbia, at an elevation of 1,550 metres. Molybdenite was first discovered during the early 1950s and the first important exploration work was done in 1964. Between 1964 and 1971, about 25,000 feet of drilling was done by various operators, as a result of which 33.7 million tons of molybdenite ore was drill indicated at a grade of 0.123%. In 1979, Shell Canada Resources entered into an option agreement with the former operator, New Jersey Zinc Corporation. Shell completed 27,000 feet of diamond drilling between 1979 and 1980 and ha s reported 75 million tonnes of drill-indicated ore with an average grade of 0.13% MoS2• This paper is a case history of IP I resistivity and magnetometer surveys done over the Casmo deposit during 1979 and 1980."

Jan 1, 1983

By L. D. Smith

"Those who submit competing proposals for projects seek to present senior management with complete and fully supported material that will not fail under questioning. Hopefully, misleading notions and omissions will have been minimized and there will have been testing of the assumptions regarding the economic, social and political environments.A capital project evaluation team can do management and itself a service by including a sound approach to the impact of inflation (and its twin problem, interest) on a project and a great disservice with an inappropriate approach to inflation.InflationHandled deftly, inflation can alter a project evaluation to show almost any result the handler desires. It must be a constant source of frustration for design people and cost estimators to spend weeks perfecting the technical aspects of a project in order to minimize costs, only to have all of their efforts set awash in a sea of financial and economic assumptions that submerge all of the detail. In all of this, inflation is perhaps the largest offender, with inflation criteria often being brought to bear at the last minute, almost as an afterthought. Perhaps this tardiness reflects the difficulty of the subject and the belief that senior management will take its own approach to the problems of inflation. Such a belief is unfair to senior management, for it is entitled to not being misled by omission. It is entitled to the full use of the skills of the evaluating team, including reasonable assumptions of the impact of inflation.Working in a consulting context, one has the opportunity to participate in the evaluation of a large number of projects."

Jan 1, 1990

By D. J. McCulla

Mineral development and utilization affect the health of the economy and the pattern of long-term development throughout Canada. There are many diverse opinions on the contribution of minerals to the economy, but there is a dearth of adequate quantitative information. This paper discusses some recent research and provides some new information.

Jan 1, 1977

By A. Mazhary, T. Huff

Sensor-based ore sorting technology is a growing area of interest due to lower-grade ore deposits and higher costs of processing, among other reasons. Among the sensors currently utilized in the particle sorting industry, X-Ray Fluorescence (XRF), as the only sensor with elemental analysis capabilities, has always attracted more attention. Currently, the bench-scale amenability tests for this sensor are performed using hand-held XRF analysers. However, this testing method overestimates the performance of the XRF sorter, and therefore, the results from these tests can be misleading and are often mispresented. The work presented here was conducted on a copper mine and investigates how the sensor’s sensitivity to copper deteriorates under different testing methods. This work compares and correlates the results of an Olympus hand-held XRF analyser, static, and dynamic sorter responses with the actual grades of the rocks. The results confirmed that, the sorter response was extremely prone to blind spots. Furthermore, the results demonstrated that although the static sorter’s responses were comparable in terms of rock identification to those of the hand-held XRF analyzer and assays, the accuracy of the dynamic sorter response deteriorated both as a function of grade of the rocks as well as the potential for blind spots. INTRODUCTION Sensor-based sorting technology has been gaining increasing attention even by larger mining corporations as ore grades decrease, deposits get deeper and therefore cost of mining and processing increases. There are various types of sensors that are currently being used in the particle sorting industry such as X-Ray Transmission (XRT), Color, Electromagnetic (EM), Near-Infrared (NIR) and others. However, none of the sensors are capable of identifying and quantifying particles by the elemental content, except for X-Ray Fluorescence (XRF). XRF is a non-destructive, surficial analytical technique used to measure elemental composition of materials. X-ray fluorescence happens when a secondary x-ray (fluorescence) is released after a sample is bombarded by a primary x-ray source. From a sorting perspective, the most common and expected issues that are associated with XRF sorting are lower throughputs compared to other sensors due to particle presentation limitation as well as the need to wash the material before introducing to the sorter. However, one important issue that is mostly neglected is how the amenability tests are performed and how realistic the obtained results are. Current amenability test procedure utilises a handheld XRF analyser (such as an Olympus InnovX, as used in this work) on multiple, generally 4, sides of the rock and uses the average measured grade as a criterion for separation. While this is a widely accepted technique, it fails to consider some important factors such as exposure time and the distance between the sensor and the particle. These factors can significantly affect the sorting outcome.

Jan 1, 2019

By Jim Dodd, Jim Paynter

"We would like to acknowledge the efforts of the following key people who helped to make this project a success.Ron Jung, instrumentation supervisor for the Golden Giant Mine, spent many hours reviewing process and instrument drawings, selecting instruments and providing hands on support during commissioning.Andy Keough, underground production supervisor for the Golden Giant Mine, was responsible for readying the underground distribution network for paste backfill.H.A. Simons Ltd. personnel who did an excellent job providing sound conceptual and detailed engineering.Fred Brackebusch, of Mine System Design who designed the paste backfill delivery systemPierre Lacombe, mill superintendent of the Louvicourt Mine, generously shared information and operating experience of their paste backfill plant.AbstractThroughout the 11 year history of the Golden Giant Mine, the primary backfilling method made use of consolidated rock fill. New backfill technologies have developed over recent years which now make it possible to use large quantities of fine mill tailings as backfill.In January of 1996, construction began on a new paste backfill plant at the Golden Giant Mine. Six months following, the plant was commissioned. This paper describes the design, commissioning and operational experience to date of the paste backfill plant."

Jan 1, 1997

By R. R. Rogers

Introduction The subject of cathodic protection is not new. In 1824 Sir Humphry Davy, in publishing the results of his investigations for the British navy, pointed out that copper could be protected from sea-water corrosion by connecting it electrically with zinc or iron. Since that time much work has been clone in this field, particularly in the protection of metals from the action of sea water, neutral brines, and treated and untreated waters. Special mention should be made of the successful protection of underground pipe-lines which formerly were badly corroded by the water in the ground. So far, magnesium alloy and zinc anodes have been the most popular. However, fairly recent work has indicated that aluminium anodes will give good service under certain conditions. The principle of cathodic protection has been applied extensively in coating steel articles with zinc and in cladding aluminium alloy sheet with pure aluminium. A valuable discussion of the fundamentals and applications of cathodic protection recently was presented in the Corrosion Handbook. A useful list of references was included in the article.

Jan 1, 1949

By J. Bigu, M. G. Grenier, S. Hardcastle

"This study was undertaken in a belt conveyor drift of an underground hard rock mine. The conveyor transported ore or waste from a crushing operation located upwind from the drift sampling locations. A 250 m section of this drift was selected and several types of measurements were taken. Average respirable concentrations in the drift were 0.43 mg/m3 and 0.19 mg/m3 for total and silica dust, respectively. From the respirable dust concentration profile along the drift, it may be possible to estimate the contribution from extended sources such as dust produced by the belt and return idlers.The airborne dust in the drift had an average mass-median aerodynamic diameter of 4.2 micron. A continuous dust monitor showed that the crushing operation produced fairly high dust concentrations (sometimes greater than 4 mg/m3) over short periods of time.IntroductionAirborne dust in the respirable range is known to be the cause of various forms of lung ailments . In underground mines, respirable dust sources are created at many stages of production. All mining operators are responsible for de signing and establishing means of reducing airborne dust. In some cases, sources of dust are well defined and suppression methods are standard.In the case of interest here, the airborne dust cloud was formed from the contribution from many sources, which may be either discrete or extended. At the experimental site, the discrete or point sources were the crushing operation and the belt conveyor transfer point (tail pulley). These sources may be controlled by proper dust capture and scrubbing systems as well as dilution ventilation. Examples of extended dust sources in the area include dust produced by the re-entrainment of settled particles along the drift. Ventilation air movement and vehicular traffic both contribute to this phenomenon. Dust produced by the conveyor is another example of an extended dust source. Caked deposits on the return strand and idlers as well as the transportation of dry material on the belt, can be major contributors. Proper wetting of roadways and muck as well as proper belt cleaning techniques can help reduce these emissions. The cleaning apparatus, used on the belt where these experiments were conducted, is shown in Figure I. These and other belt cleaning techniques are described in more detail elsewhere."

Jan 1, 1987

By A. E. Boudreau

Abstract-It has long been recognized that platinum-group-element (PGE) deposits in layered intrusions preferentially occur in intrusions that crystallized from high-Mg parent magmas. Recent studies suggest that evaluation of any given intrusion for economic PGE potential should also include assessment of the PGE, sulfur and chlorine concentrations in the cumulates and potential parent liquids. PGE: Magmas that contain relatively abundant Pt and Pd are the best candidates for forming economic deposits. Although analyses of coeval sills and dikes are the best indicators of primary magmatic PGE concentrations, analysis of the cumulates themselves is also valuable. For example, within the Stillwater complex, background PGE values in cumulates from the ultramafic sections of the complex contain, on average, several 10s of ppb Pt and Pd. Background concentrations of this order are suggestive that the magma was not depleted in the PGE. Sulfur: Conventional petrogenetic models for the formation of PGE deposits in layered intrusions require the PGE to have been concentrated during a magmatic sulfide-saturation event. In contrast, some hydrothermal models suggest that sulfur and the PGE were mobilized from footwall cumulates by upward- migrating, high-temperature hydrothermal fluids. Both models suggest that significant PGE deposits are likely to occur at and below the level where stratigraphic increases in whole rock sulfur concentrations occur. Chlorine: In both the Stillwater and Bushveld complexes the cumulate sequences below the major PGE-bearing zones contain anomalous Cl-rich apatite. The chlorapatite component of apatite in these rocks may exceed 40% and, in the Stillwater complex, typically exceeds 90%. It is stressed that pristine igneous mineral analysis and not whole rock data be used, as whole rock Cl concentrations may be affected by very localized (grain boundary), low-temperature alteration. Intrusions that crystallized from high-Mg, high-Cl magmas appear to have the best potential to host significant PGE deposits.

Jan 1, 1995