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By F. R. Joubin

MR. CHAIRMAN, Members of the C.I.M., and Friends -particularly friends, because I am not entirely a stranger in your city. I was last here some five years ago and it has given me a great deal of pleasure this evening to be able to say "Hello" again to those I had met at that time, when Bourlamaque and V al d'Or were very busy centres of intensive and successful gold exploration. My remarks this evening have to .do with Canada's Place in the Atomic Age. They will be of a general nature but I hope to tell you ?enough to whet your appetite so that you may be provoked into per-.suing the subject further. Now, atomic developments have become quite commonplace. Words like radioactivity, reactors, nuclear fission, and so on are known to everyone, even the youngsters. I re-member two or three years ago one of my office boys came to me and said "Mr. Joubin, I would like a raise." I gave the request a few seconds of serious thought and finally said "Alright, Jimmy, we'll give you a raise." However, he made no effort to leave, so after a -couple of seconds more I said, "Is there something else ?" and he said "Yes, Mr. Joubin, could you make that raise 'radioactive' to the first .of the year ?"

Jan 1, 1958

By P. C. Patnaik

Performance of industrial gas turbine engines in terms of power output, reduced cooling and efficiency have been continuously increasing in parallel with aero gas turbines due to the advances made in the development of new materials, protective thermal barrier coatings (TBCs) and the advanced diagnostics to monitor service induced problems such as hot corrosion, thermal and thermo-mechanical fatigue and other operational issues, Environmental attack (hot corrosion or high temperature oxidation) is a common degradation mode in the hot section of the gas turbine, Hot corrosion occurs when Na or K bearing compounds in the environment or in the fuel combine with other contaminants such as S and Pb or V to form corrosive sulphates or vanadates thus attacking the protective oxide on the turbine airfoil, These problems pose far more threat to new turbine engine materials such as directional solidified, single crystals and ceramic matrix composites (CMCs). The CMCs due to their increased temperature capability, when used in the combustion chamber, are likely to reduce the peak temperatures attained during combustion and therefore provide the benefits of reduced emissions of oxides of C and N, These issues will be reviewed critically and their impact will be assessed on gas turbine lives. With respect to alternate fuels, past experience has shown that utilization of residual oils and coal derived fuels in gas turbines have resulted in complex deposition and corrosion processes, In recent years biomass derived alternate fuels have been used either through a gasification cycle or through direct firing of the biomass derived liquid fuel with a view to reduce Green House Gases (GHGs) and improve the climatic conditions. In both cases, the resulting high temperature corrosion processes (in the presence of alkaloids in the fuel) are also very complex, leading to premature removal of hot section components, Technology solutions mitigating these fundamental problems will be reviewed and solutions presented.

Jan 1, 2005

By L. A. Homeniuk, R. J. McH. Clark

"The Maurice Bay deposit, the Stewart Island showing, the Fond-du-Lac deposit, the Middle Lake showing and the Nisto deposit are located on the North Rim of the Athabasca Basin. They are probably unconformity-related. These occurrences tend to be small. The Fond-du-Lac and Maurice Bay deposits are the largest and contain 450,000 kg and 650,000 kg of U10 8 respectively.Pitchblende is the main uranium mineral of all the occurrences, except at Middle Lake where autunite predominates. A II of the deposits are overlain and partially hosted by the Manitou Falls Formation of the Athabasca Group, except the Nisto deposit which is entirely within basement rocks, and the Maurice Bay deposit which is partially within the basement and overlying the Fair Point Formation of the Athabasca Group.The North Rim deposits are considered to be genetically similar to the other unconformity-type deposits found in northern Saskatchewan. It is suggested that a mechanical concentration of uranium may have occurred in heavy mineral beach sand type placers. The stability of the uranium minerals may have been enhanced by special local conditions. The fossil placers, after hydrothermal alteration and enrichment, would form the apparently ""rootless"" occurrences of uranium found totally within the sandstones above the unconformity.IntroductionAt least five deposits and showings and one train of mineralized glacial erratics of unknown provenance have been located on the North Rim of the Athabasca Basin from Maurice Bay in the west to Black Lake in the east. Distributed over a distance of 250 km, (Fig. l), they occur near the edge of the Basin, and are probably unconformity-related. The following have been identified from west to east (Fig. 2): The Maurice Bay deposit, the Stewart Island showing, the Isle Brochet train, the Fond-du-Lac deposit, the Middle Lake showing, and the Nisto deposit."

Jan 1, 1986

By C. O. Aksoy

Operating the underground marble quarries effectively, it is important to evaluate the deposit blocks economically which are affected by the suitability of the topography and configuration of bedding. The joint sets within the deposit and the spacing between these discontinuties are also of great importance. In this study, the marble deposits that could be geomechanically eligible for underground excavation have been selected throughout Turkey and these selected reserves have been classified accordingly by Q-Rating System. These classified marble deposits that forms groups of 1,2, and 3 (groups were determined by evaluating the O-rating, topography, quarry situation, cracks, joints etc.) are convenient for this type of production. Nevertheless, when the auxiliary factors (topography, location, production method etc.) regarding the deposit have also been investigated, the most convenient sub-group of deposits (Afyon Tiger Skin, Burdur Beige, Diyarbakir Pink and Mugla White) have emerged. The sizing of the pillars have been performed utilising Bieniawski?s stress profile. The LAMODEL software, developed by National Institute for Occupational Safety and Health (NIOSH), USA and run under the laminated displacement discontinuity method, has been used to size the pillars. This work brings in a novel opportunity to Turkey, in which no underground marble quarry has been attempted up-to-date similar to its several examples in Italy, USA, etc. This study serves as a reference for the marble operators and for the pioneering application of laminated displacement discontinuity method in hard rocks.

Apr 1, 2005

By Robert B. Parsons

"It is quite likely that more than a handful of junior exploration companies will receive some startling news from their accountants this spring when 1989s tax returns are being prepared. These companies could find that, for the first time ever, they will have to write a cheque to the federal government on account of a new federal capital tax which became effective July I, 1989IntroductionMany mining companies which have never had to pay a federal income tax are finding that they indeed have a tax liability for 1989. Non-producing companies, such as junior exploration companies, almost automatically assume that they don't have to pay any income tax. But, a new tax imposed under the Income Tax Act catches especially the company that has no income.Effective July 1, 1989, a federal capital tax (some call it a corporation minimum tax) is payable by any corporate carrying on business in Canada where the corporation has ""taxable capital"" exceeding $10 million. As a result of the popular use of flow-through shares in recent years, many junior exploration companies are finding that their balance sheets show capital stock over $10 million, and that they are consequently caught by the new tax. Further, some of these companies are finding, to their chagrin, that the tax for 1989 was due on February 28, 1990, and that non-deductible interest is ticking away on unpaid taxes."

Jan 1, 1990

By Bern Klein

Motivation for Improved Energy Efficiency in Mining ? Canada potentially adopting Greenhouse Gas Emissions and Intensity Legislation in 2013 ? BC -Climate Action Plan and Energy Conservation Agreement in 2008 ? BC Energy Plan 2007 -BC Hydro is mandated to save 50% of new load growth ? TSM Initiative -Energy Management, Energy Reporting, Setting Energy Targets, GHG Management BC MOU for Energy Conservation Agreement -MEMPR, MABC, BC Hydro

May 1, 2010

By Jonathan Tsang, Ali Merati, Jonathan Beddoes

Due to economic factors, many aircraft in service today have been operating for more than 30 years even though they were initially designed with a service life of 20 years. Improved damage management models are therefore needed for use in life prediction and management of the aging fleets of aircraft. Currently, the generally accepted procedure in fatigue life prediction methodologies is to back calculate the equivalent initial flaw size (EIFS) using established long crack growth data. However, it was observed from studies carried out at the National Research Council Canada that nucleation and short crack growth constitute up to -95% of the fatigue life. As a result, it seems that the significance of the short crack regime has been underestimated and must be further investigated and fully understood before an accurate holistic life prediction methodology can be realized. Unlike long cracks, local microstructural features such as grain boundary, grain size, inter-particle spacing, and texture play dominant roles in the behavior of short cracks. An extensive study has been carried out to evaluate different crack detection and monitoring techniques in the short crack regime for AA2024-T3. The results will be presented in detail.

Jan 1, 2004

By M. Dupuis

It has been previously demonstrated [l] that there is no obvious thermal balance related issue limiting the size of a Hall-Héroult cell. Yet, it is well known that a forced-air sidewall cooling system is part of the AP50 cell design [2], In the present study, the authors analyze the impact of thermal loading on the mechanical deformation of high amperage cell potshells. The effect of adding cooling fins or a forced-air sidewall cooling system is then assessed.

Jan 1, 2005

By R. Loney, M. Militzer

There is a significant demand for new high strength steels with fine grain sizes for structural applications. One approach in this regard is to develop hot-rolled HSLA steels where refining the microstructure leads to increased strength levels, e.g. 700 MPa yield strength, that can be attained by suitable modifications of chemistry and processing. Here, an HSLA steel is investigated that contains 0.05wt%C-1.65wt%Mn-0.20wt%Mo¬0.07wt%Nb-0.02wt%Ti and approaches the above strength class. The ability to control and predict the mechanical properties of hot rolled steel depends strongly on the thermomechanical processes, which the steel undergoes. The final microstructure and, thus, the properties of the hot-rolled steel are a function of the austenite decomposition obtained during accelerated cooling on the run-out table and precipitation during coiling. The austenite-to-ferrite phase transformation under run-out table conditions has been investigated using a Gleeble 3500 thermomechanical simulator equipped with a dilatometer. The effects of cooling rate and initial austenite microstructure including the degree of work hardening on austenite decomposition kinetics and ferrite grain refinement have been quantified. Results show that grain refinement can be optimized by the presence of work hardened austenite and accelerated cooling. Based on the experimental results, a model is proposed to predict the transformation start temperature and the resulting ferrite grain size for run-out table cooling conditions.

Jan 1, 2004

By J. Hansen

"ABSTRACTThe paper addresses the application of automated monitoring, control, and navigation to improve dragline performance. SummaryImproving dragline performance in the Canadian coal mines is critical to the continued success of the industry. Draglines represent a large capital investment and coal prices are low by historic standards. This paper argues that the introduction of monitoring, control, and navigation on draglines offers an opportunity to significantly reduce a dragline’s operating cost per cubic metre moved. To place the importance of this in perspective, a North Dakota mine calculates that every 1% increase in dragline productivity means a savings to the mine of US$340,000 per year. MonitorsAutomated dragline monitoring is a well established technology with commercial products available since the early 1980s. The three main reasons for placing monitors on draglines are (Walker, 1993):1. productivity increases: reduce variations between different operators’ performance across different shifts;2. quality increases: increase the percentage of ore and waste loads that go to the correct destination; and3. special projects (engineering projects): justify installing static field exciters and regulator upgrades; implement power management; aid operator training; study high performance buckets, rigging changes, and various excavation sequences.Mines as diverse as Kennecott’s Cordero- Rojo Complex in the United States and Natal Coal Corp.’s Optimum Mine in South Africa report dragline productivity increases of 10% to 20% in the region attributed to the implementation of dragline monitoring."

Jan 1, 2000

By M. E. Hurst

Introduction Between 1903 and 1905, W. Mclnnis, of the Geological Survey of Canada, made a micrometer traverse of the Kawinogans (Crow) river from Kapkichegimaga lake to its junction with the Otoskwin river. He reported that a belt of Keewatin rocks, 1 to 4 miles wide, was exposed along the course of the river for 17 miles east of Kapkichegimaga lake. Prospectors and exploration companies paid little attention to the mineral possibilities of this belt until the summer of 1928 when, with the adoption of airplane transportation, the area became readily accessible. Within a short time widespread interest was aroused by the announcement of attractive finds, and a mild rush followed. During the winter months, hundreds of claims were staked on either side of Crow river for 12 miles east of Pickle lake. In the summer of 1929, much of this ground was systematically explored and a considerable amount of development work was done on the known deposits.

Jan 1, 1930

By Xuanxue Mo, Kaihui Yang

"Abstract- The Laochang mine, located in the Sanjiang area of southwestern Yunnan Province of China, is a volcanogenic massive Pb-Zn-Cu sulfide deposit. It is hosted by a pyroclastic sequence of Barly Carboniferous age, namely the lower member of the Yiliu Group, which was intruded by syenite and rhyolite porphyry . The volcanic suite is basaltic or basaltic-andesitic in composition, has alkaline affinities, and is associated with the initial rifting along the margin of the Baoshan-Shanstate continental rnicroplate (Yang, 1989). The ores are typically Pb>Zn>Cu in composition, averaging 3.820Jo Pb, 3.51% Zn, from 0.01% to 1.85% Cu (0.107% av.), a high average content of Ag (113 g/t) and recoverable amounts of Au, Tl, Gd, Ga, Ge, In. A massive sulflde zone, in which lenticular and stratiform orebodies are localized in a sulflde-carbonate-silica shale unit or sulfldic tufflte horizon that usually overlies coarse-grained pyroclastic rocks, is underlain by a stringer sulflde zone developed in a subvolcanic intrusion or volcanic sequence. The sulfide mineral assemblages, from the top to the bottom of the deposit, are: realgar + orpiment - galena + sphalerite + pyrite- chalcopyrite + pyrite + pyrrhotite + arsenopyrite. Oxide and sulfate minerais occur rarely in the massive ores. The massive ores are generally fine-grained and banded, but coarse-grained ore, colloform and framboidal texture, and growth-zoned pyrite and sphalerite are common. Sedimentary features such as graded bedding, brecciated and deformed ore clasts, and chaotically emplaced blocks, are well preserved, indicating that the massive orebodies have undergone slumping and dis­ placement. Alteration is weak in the hanging-wall rocks, but strong in the stringer zone. Two dis­ tinctive alteration zones have been identified: the upper zone, characterized by an assemblage of quartz, carbonates, chlorite, albite, zeolite and sericite, and the lower zone containing diopside, trema­ lite, actinolite, gamet, clinozoisite, and epidote.The general features of the Laochang deposit are in accord with the descriptive mode! of VMS deposits (Lydon, 1984). However, it falls into neither the Zn-Cu group nor the Zn-Pb-Cu group chemically (Franklin et al., 1981). The depositional setting of the Laochang deposit is quite different from Cyprus or Besshi-type massive sulfide deposits. Laochang is hosted by alkaline lavas that were erupted in a submarine continental rift. Although some features of the Laochang deposit are similar to those of Kuroko-type deposits, there are remarkable differences in the alteration mineral assemblage, the proportion of ore-forming elements (lead enriched) and the amounts of oxides and sulfates. These suggest corresponding differences in ore fluid composition and the associated ore-forming environment. Thus, the authors suggest that the Laochang deposit may be a distinct type of VMS deposit."

Jan 1, 1993

By W. Beres, M. Bielawski

Recent research on the development of erosion resistant coatings has been directed to the finite element modelling of the behavior of coating and substrate, and their interface under the impact of eroding particles. The approach presented in this paper is based on advanced computer simulation techniques using ABAQUS/Explicit to investigate stress and strain at the surface and at the coating/substrate interface of multilayer coatings under single particle impact. It was found previously that solid particle erosion mechanisms are predominantly governed by the kinetic energy of the impacting particles. However, recent modelling efforts revealed that effects of various material models could be also significant. Therefore, different material models representing relevant coating and substrate properties were investigated and the effects of these models on the coating/substrate response were studied. Particularly, differences between elastic, elastic-plastic and brittle cracking model responses were assessed.

Jan 1, 2006

By J. A. Folinsbee, Andre Robitaille, Tony Y. Chong

"Conventional crushing and grinding is followed by gravity concentration to recover free milling gold. Refractory gold, finely disseminated within the pyrite and arsenopyrite matrix, is recovered by flotation followed by pressure oxidation, cyanidation, and cementation. Non-refractory gold is recovered by cyanidation/CIP processing.A comprehensive test program aimed at improving flotation recovery was initiated in June 1995. Plant testing indicated that flotation tails value could be significantly reduced using mechanical flotation cells. Based on these test results, a flotation circuit that incorporates one of the three existing flotation columns followed by mechanical scavenging and cleaning was developed. Detailed engineering was completed in September 1996. Construction started in February 1997 and was completed in 3 months at a cost of $3.2 million. An on-stream X-ray analyzer was installed to provide real-time arsenic and iron analyses and inferred sulphur value on some of the flotation streams.The new flotation circuit proved to be an instant success. Flotation tails values were reduced by 27%. Final tails solids and solution was reduced from 0.035 to 0 023, and 0.0014 to 0.0006 oz/ton Au, respectively. Based on a mill throughput of 1,620 stpd this decrease in tails value will result in an increased gold production of 7,500 ounces per year. The payback for the project is estimated to be around one year.This paper describes the evolution of the project from bench scale testing to commissioning. Also, the operational and economic impacts on down stream processing are highlighted"

Jan 1, 1998

By Harold L. Gibson, Don H. Rousell, Ian R. Jonasson

"Abstract - The Sudbury Structure consists of three major components: 1) the Sudbury Basin; 2) the Sudbury Igneous Complex which surrounds the basin as an elliptical collar; and 3) an outer zone of shatter-coned and intensely brecciated footwall rocks. Although the Sudbury Event which formed the structure may be unique, the area has, in fact, been shaped by a series of tectonic, magmatic and mineralization events which can be considered in terms of two Wilson cycles of continental extension and closure. The first cycle, from 2500 to 1700 Ma, included the following events: doming (uplift of Levack Gneiss Complex); NE-SW extension (Matachewan dikes); N-S to NW-SE rifting (faults, mafic intrusions, sedimentation, and Ni-Cu-PGE and U mineralization); NW-SE extension (Nipissing diabase, and Ni-Cu-PGE, Ag, Co mineralization); and NW-SE and NE-SW closure (Penokean Orogeny, 1900 to 1700 Ma) with superimposed meteorite impact (1850 Ma, Ni-Cu- PGE, Zn-Cu-Pb deposits). The second cycle, from 1700 to 1000 Ma, included: N-S extension (alkali metasomatism, Au); N-S extension (hornblende diabase dikes along the Murray fault set); NNESSW extension (olivine diabase dikes); NE-SW extension (Fecunis Lake fault set); and NW-SE closure (Grenvillian Orogeny).The rich and diverse Ni-Cu-PGE and subordinate Zn-Pb-Cu and Au mineralization of the Sudbury region is related to endogenic and impact-triggered crustal extension and magmatism. The Sudbury Structure apparently was the site of a triple junction or hot-spot. The Sudbury ores, although located within an impact structure, are analogous in terms of age and tectonic setting to Ni-Cu-PGE and Zn-Pb-Cu ores elsewhere in the world. Meteorite impact accentuated on-going ore forming processes and magmatism at Sudbury."

Jan 1, 1997

By K. J. Daun, C. J. Shi

UsiborThrough the second step heating at 900 °C, the spectral emissivity shows a gradually decreasing trend with increasing soak time, caused by the surface phase transformation from Al® 1500P coupons are austenitized in a Gleeble 3500 thermomechanical simulator using a two-step heating procedure in an argon atmosphere. Variations in spectral emissivity are measured in-situ using a near infrared spectrometer and ex-situ with a Fourier transform infrared reflectometer. Microstructural evolution and surface roughness are investigated using optical microscopy, FE-scanning electron microscopy, and a surface profilometer. A series of phase transformations of Al-Fe-Si intermetallic phases at the coating/steel substrate interface cause the surface phase and surface roughness to change, which in turn influences the spectral emissivity. At the beginning of the first heating step, the coupons have very low spectral emissivity, due to the molten Al-Si coating. Spectral emissivity increases significantly with increasing soak time from 5 to 12 minutes, associated with the surface phase transformation of the coating into Al7Fe2Si intermetallic phase and an increase in surface roughness. 5Fe2 into AlFe intermetallic phase with a decrease in surface roughness.

Jan 1, 2015

By R. D. Brown

"Finance Minister Donald Macdonald's budget of May 25, 1976 featured a restructuring of the anti-inflation profit controls and a grab bag of tax changes, some of direct interest to the mining industry. All Canadian taxpayers now will be permitted to write off immediately 100% of mineral and oil and gas exploration expenses included after• May 25, 1976 and before July 1 1979. The cost of acquitting Canadian resource property after May 6, 197.4 from a federal or provincial government will now clearly be included in Canadian development expense, and provincial drilling and exploration incentives received after May 25, 1976 will not reduce exploration and development expense for federal income tax purposes. Under tough new anti-inflation profit controls, all controlled businesses, except distributions, will essentially have one uniform set of rules for• determining allowable profit margins; this allowable margin will be determined by product line or by over-all net margin and will be 85% of the higher of the margin obtained in the five years preceding October• 13, 1975 or the one year preceding May 1, 1976. The basic capital cost allowance system is to continue, but many rates will be revised. The ability to offset losses created through claiming capital cost allowances on leased equipment, etc. against other income will be ended with respect to transactions entered into a/te1• budget night. Miscellaneous other tax changes will raise the low rate base for Canadian-controlled private corporations to $750,000 increase retitement plan contribution limits and reduce the rate of branch tax imposed on branches of corporations resident in a country with which Canada has a comprehensive tax treaty to equal the withholding tax rate on dividends under that treaty."

Jan 1, 1976

By D. Ingram

"PRIMARY DUST COLLECTOR A. 42,000 CFM James Howden Fan Z-6 Size 3650 Fan Dia 40"" HP 75It was found that the fan was not large enough to remove the air that was displaced by the trucks dumping. So it was removed and an enclosure was installed to isolate the gyro from the rest of the building.B. FANSJames Howden Fans Model RPM 3500 Series 357 FW HP 10These fans were installed when the first dust system was put into operation. It was found that the high RPM and extreme fan wear caused a major maintenance problem. These fans were replaced with Chicage Blowers Model SWS1 RPM 1180 Dia 36"".DRY CYCLONE COLLECTORS A.,Three four foot rubber lined cyclones. Four six foot rubber lined cyclones.All under flow. Water is controlled manually and gravity flows to a central sump box. From there it flows to the grinding circuit in the Mill.Cyclone under flow product runs between 100 and 200 tons of dust per 24 hours with a screen analysis 30% + 400.The cyclone under flow product is diluted to about 3 to 4%. Solids total gallonage approximately 400.B.,Elbair Wet Scrubber125 HP RPM 56042,000 CFM,Model PX861The Elbair collects the total product from the discharge. Of the Cyclone fans the under flaw goes to the Mill - the Elbair discharges stack goes to atmosphere.The Elbair wet scrubber had to be redesigned in order to keep it in service."

Jan 1, 1976

By M. El Tokhi, H. Arman, B. M. Amin

"This paper aims to overview some mechanical and physical features of the gabbroic rocks. The study has two phases: filed study/in-situ measurements and laboratory work. During the field studies, rock block samples were collected from different locations of the study area to represent the different types of the gabbroic rocks. Either core or rock samples for various tests were prepared from rock samples taken to the laboratory. The unconfined compressive strength (UCS), indirect tensile strength (ITS), point load index (PLI), Schmidth hammer rebound value (SHV), slake durability index (SDI), sonic velocity (SV) and unit weight (UW) test were carried out either on the selected rock block samples or core samples.INTRODUCTIONThe geology of the United Arab Emirates (UAE) has been divided into three major rock units (Lippard et al., 1986); an autochthonous succession, allochthonous units composed mainly of Mesozoic rocks and include the Sumeini Group (concomittent slope sediments), Hawasina Complex (basinal sediments) and the Semail ophiolite nappe (massive slice of former oceanic crust), that were emplaced as a series of thrust nappe in the Late Cretaceous and Neo-autochthonous sequence of Maastrichtian and Lower Tertiary sediments.The Semail Ophiolite (600 km long and up to 150 km wide) is thought by some authors (Glennie et al., 1990) to have been generated along a subduction related back-arc spreading axis during the Cenomanian-Turonian and was obducted onto the Arabian continental margin during the Campanian. Others, however, consider it to represent a primitive arc-spreading center related to oblique subduction Lippard et al., 1986). The Ophiolitic rocks in the study area comprise mantle and crustal sequences. The mantle peridotite and crustal gabbros are the dominant rock types of the exposed Semail Ophiolite north of the Hatta zone. This paper is only concentrated on the gabbroic rocks."

Jan 1, 2015

By E. W. Mountjoy

THE Exshaw formation is a thin but very persistent black shale unit generally well exposed along the easterly scarp faces of the fault blocks comprising tl1e front ranges of the Rocky mountains. It is over lain by the Mississippian Banff shales and silty shales and underlain by the massive Palliser Limestone formation of late Devonian age. The Exshaw continues eastward under the plains of Alberta and on into Saskatchewan, with little change until it reaches the surface of the Palaeozoic-Mesozoic unconformity. During the summer of 1953, the writer was working- with a field party under Dr. J. L. Usher in the front ranges of the Alberta Rocky mountains. This party, sent out by the Mobiloil Company, conducted a geological survey of Devonian rocks between the towns of Banff and Jasper. The writer helped to describe and map these Devonian rocks and obtained first-hand information concerning the Exshaw shale and its relationship to the underlying and overlying sediments. Additional information was obtained from reference material and from a number of geologists whom the writer has consulted. Grateful acknowledgment is offered to them, to the Mobiloil Company for releasing field information, and to F. W. Beales and W. P. Hancock who helped edit the original paper for publication. Information from areas north and smith of that studied and from bore holes on the prairies is referred to. Localities mentioned may be found in Figure 1.

Jan 1, 1956