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By A. G. Scobie

A spectrographic method for the determination of small amounts of gold and the platinum metals in ores has been developed. By means of this method, an assay of 0.001 ounce per ton on one assay ton samples is possible, and by seecrrographic adjustments the sensitivity may be increased to 0.0001 ounce per ton. All the prec10us metals may be determined from one spectrographic arcing with an accuracy of about 5 per cent average deviation from absolute values, and the complete analysis of an ore or similar product may be reported five or six hours after receipt of sample.

Jan 1, 1945

By T. Patching

"Introduction The occurrence of coal was first reported in the Drumheller area in 1793 but it was not until 1912 that production of coal was recorded. In that year 13,000 tonnes were mined in the Drumheller area. Three years later the Drumheller mines ranked next in the Province to those in the Crowsnest and Lethbridge districts, with an output of 225,000 tonnes. By 1917 production had increased to 600,000 tonnes, moving Drumheller to second place in output in the province, second only to the Crowsnest district. It held this rank until 1960. Production, almost all from underground mining, rose to over a million tonnes a year by 1920 and remained between one and two million tonnes per year until 1954. Competition from newly discovered oil and natural gas, beginning around 1950 caused a steady loss of domestic coal markets, especially from underground mines. By 1960 Drumheller's production had fallen below a half a million tonnes per year and the field ranked third in output in the province, being surpassed by new stripping operations in the Castor field. By 1965 only a couple of producing mines remained in the Drumheller valley, and output was only about a quarter of a million tonnes per year(1). Throughout the life of the field production was seasonal, depending mainly on the domestic heating market. In 1979 the last mine ceased production. For the last several years of its operation it had remained open in the summers to provide tours for visitors(2). The Drumheller mining operations were located along or near the Red Deer River valley which is 300 to 400 feet deep, and extended from a few miles above the city of Drumheller to East Coulee, about 13 miles down the river in a south-easterly direction. Intervening mining communities existed for some years at Wayne and Rosedale. During the peak years of production some 2000 to 2500 miners and their families lived in these communities and the surrounding areas."

Jan 1, 1985

By François Baillargeon

Two types of ore deposit provide the bulk of the world nickel production. They are the hypogene magmatic massive sulfide deposits and the supergene lateritic deposits. Platinum group elements (PGE) are also extracted from magmatic sulfide deposits. Recent sky-rocketing price of palladium has prompted the mineral industry to seek alternative resources. In such a manner has emerged the Lac-des-Iles type of target, a very low sulfide-bearing bulk tonnage type of deposit. Furthermore, unconventional (e.g. non-magmatic) types of deposit are now sought more intensively (Wilde et al., 2003). Considering both this trend of the PGE Industry, and that only a few magmatic deposits account significantly for the world nickel production, someone may wonder if a diversification of the hypogene nickel resources base would not be needed in the near future. Laterites are residual deposits developed on ultramafic rock under wet tropical climate. Are all ultramafic protoliths equal to generate high-grade lateritic deposit? Are some preweathering processes important to generate favourable ultramafic protoliths? The mineralogical heterogeneity of some ?dry? lateritic nickel deposits renders their ore beneficiation difficult. Is the type of nickel-bearing mineral found in the protolith a significant factor influencing the laterite heterogeneity? To contribute to answer all these questions, we have undertaken a research project on the nickel occurrences of the southern Quebec serpentinite belts. Why choosing this specific region for such a project? First because, due to continuous mining of asbestos ore since 1870, the serpentinite belts of this region are among the best exposed and studied in the world. Secondly, this region host a complete spectrum of nickel deposits that have been described before in the scientific literature. Furthermore, this region is slightly to moderately metamorphosed which make it perfectly suited to study the departure from magmatic nickeliferous paragenesis through various metamorphic conditions. As a matter of fact two orogenic events affected this region, the Taconian, in Ordovician time, and the Acadian during the Devonian. The magnitude and the timing of these dynamo-metamorphic events vary considerably through the region (Gauthier et al., 1994). These variations are now well constrained due to precise age dating.

May 1, 2003

By L. Gutierrez, M. Pawlik

The rheology artificial mixtures of bitumen with fine quartz of varying bitumen content, as well as actual oil sand ores, was investigated under different physicochemical conditions (pH, temperature). All rheological measurements were conducted using a Haake Rotovisco VT550 rotational viscometer, connected to a fixture specifically designed to measure properties of settling suspensions. It was found that at low bitumen contents (1 %, wt.) the pH of the slurries was the most important parameter that controlled the rheology of quartz-bitumen slurries. At higher bitumen contents (10%, wt.), it was a combination of high temperature and high pH that gave the lowest apparent viscosities and yield stresses of the model mixtures. These model observations correlated well with the rheology data obtained for slurries of actual oil sand ores. The overall results were discussed in terms of aggregation-dispersion phenomena between bitumen and mineral particles.

Jan 1, 2009

Waste rock extracted from a mine is typically stored nearby on the surface. Such waste rock piles must be designed to ensure their geotechnical and geochemical stability during the mine operation and after closure. The optimal construction of a pile requires detailed planning. Deposition should involve benches of limited height to control the global slope angle, based on the long term factor of safety. It can also be advantageous to compact the top of each bench and to give the surface an outward inclination to control water flow by limiting infiltration and favoring lateral diversion. When part of the waste rock contains reactive minerals, it is also deemed necessary to use selective placement with the non-reactive portion to prevent direct exposure to natural conditions. The construction must be well documented, and include data from the monitoring program. These and related aspects are presented and discussed in the paper.

Aug 1, 2013

By J. Fellowes, Z. Liang, J. Robson, M. Kenyon

"Dispersoids play a significant role in the recrystallization and texture development for wrought Al-Mg-Si (6xxx series) alloys by inhibiting grain boundary motion. It is therefore important to understand the precipitation kinetics of such particles. It is the additions of Mn and Cr in Al-Mg-Si based systems that can lead to dispersoid phases being formed. These phases are currently thought to nucleate on ß’-Mg2Si via an intermediate semi-coherent precipitate. Scanning transmission electron microscopy (STEM) has been conducted to study the precipitation of a-Al(CrFe)Si and a’-AlCrSi dispersoids. Corresponding electron dispersive spectroscopy (EDS) has been used to distinguish the dispersoids. The volume fraction and size distribution of dispersoids has been measured as a function of distance across a grain. Electron probe microanalysis (EPMA) has been conducted to study the inhomogeneity of elements in the cast structure and the effect on dispersoid precipitation. Dispersoid free regions have been observed in the microstructure correlating to regions depleted in the dispersoid forming elements.INTRODUCTION Al-Mg-Si (6xxx series) based alloys are increasingly being used in the automotive industry. The primary reason is to reduce the weight of vehicles, resulting in a reduction of CO2 emissions and increased fuel efficiency. The demand for 6xxx series is predicted to increase over the coming decade. Due to the high cost and CO2 emissions produced by raw extraction of aluminium, close loop recycling of these alloys becomes a more important process. However recycling of automotive alloys can be difficult due to pick up of impurity elements such as Mn, Cr and Fe. The addition of these elements can form dispersoid particles during early heat treatment processes. Although a controlled population of dispersoids is necessary to control the grain structure during thermo-mechanical processing, a significant change to the dispersoid population due to a composition change could profoundly influence the final microstructure, affecting the final properties of the material. More research is required on the precipitation and effect of additional minor alloying elements; in order to increase the 6xxx series alloys recyclability."

Jan 1, 2018

By S. G. Shabestari

In the metal casting industry an improvement of component quality mainly depends on better control over the production parameters. Thus, thermal analysis cooling curve of the alloy is used for process control in aluminum casting industry. Cooling rates of the alloy during solidification process affect microstructure, grain size, eutectic silicon morphology, and dendrite arm spacing (DAS). In this research, effect of cooling rate on the microstructure and solidification parameters of 319 aluminum alloy that is a widely used alloy in automotive industry, has been investigated by means of thermal analysis. Seven different cooling rates have been obtained by using CO2-bonded silica sand molds with two different wall thicknesses, hot-work tool steel molds (H13) with and without coating, thin-wall steel molds with different coatings. In each case, cooling curve and first derivative cooling curve have been plotted by use of very accurate thermal analysis equipment. Effect of different cooling rates on solidification parameters e.g. Nucleation temperature (TN,a), nucleation undercooling (ATN,a), recalescence temperature (TR,a), solidification range (AT,s), and total solidification time (t 0 have been studied in the liquidus region. Microstructural evaluation has been carried out and DAS were measured in all solidification conditions. A numerical equation was proposed to predict cooling rates via measuring DAS in 319 aluminum alloy. Nucleation process and the effect of cooling rate have been interpreted by using thermal analysis cooling curves and microstructural study.

Jan 1, 2004

By P. Cleyle, J. H. Masliyah, R. S. Chow, Z. H. Xu, Z. A. Zhou

Bubble nucleation in water under dynamic conditions was investigated using an autoclave at an air saturation pressure of 7 atm. Agitation during air saturation of water was found to be crucial in enhancing tiny bubble formation. More bubbles nucleated on hydrophobic surfaces at a higher agitation rate, due to cavity formation by the more intense hydrodynamic conditions. Flotation recovery of bitumen from oil sands demonstrated a significant role of bubbles nucleated in water: more than 50-170% increase in bitumen recovery from different oil sands was obtained by using air supersaturated than the regular water.

Jan 1, 2009

By C. E. Lancelle, J. T. Volk, H. F. Wang, D. Fratta

"The Main Injector Neutrino Oscillation Search (MINOS) Near Detector Hall at Fermilab and the Lafarge – Conco Mine are located approximately 100 meters underground in the Galena-Platteville dolomite just below its contact with the overlying Maquoketa shale in Northeastern Illinois, USA. A new cavern was excavated adjacent to the MINOS Near Detector Hall at Fermilab to house the near detector for the Off-axis Neutrino Appearance Experiment (NOvA) program. During this excavation approximately 1150 cubic meters of shale rock were removed. Tiltmeter arrays consisting of a series of hydrostatic leveling sensors (HLS), which are spaced regularly over a total distance of 50-to-100 meters, were used to monitor subsurface deformations. The tiltmeter response in the MINOS Near Detector Hall due to the NOvA cavern excavation is approximately thirteen times the estimated response based on using laboratorydetermined properties. The discrepancy between modeled and measured tilt is likely due to differences in Young’s Modulus in the rock mass versus in a small laboratory sample. Amplitudes of measured solid earth tides differ from the amplitudes of theoretical solid earth tides by up to 40 percent for both arrays. This is likely due to a local heterogeneity or discontinuity.INTRODUCTIONLong baseline tiltmeters have been used to record small earth movements since the early 1900s. One of the first studies using long baseline tiltmeters to measure earth tides was published by Michelson (1914). He used a leveled 152-meter long, 0.15-meter diameter tube half-filled with water connecting two concrete-lined pits. The pipe was trenched 1.75 meters underground in Williams Bay, Wisconsin in a sandy-clay soil. Initially only an east-west line was used, though a north-south line was added after it was seen that viable results were obtained. Measurements were made by hand either hourly or once every two hours depending on the time of day. When compared to 0.7 times the calculated earth tides, the tiltmeter signal matched almost exactly. This excellent result began the use of long baseline tiltmeters to measure small earth movements."

Jan 1, 2015

By A. J. McLaren

Introduction Gold holds an important place among the mineral products of Manitoba. In value, it ranks second only to copper, which in 1931 attained first place. The gold production increased from 23,189 fine ounces in 1930 to 102,969fine ounces in 1931. The production for 1930, worth $479,359, came almost entirely from the Central Manitoba mine. The production for 1931 was worth $2,128,558, of which $1,509,018 came from the Flin Flon mine, $528,951 from the Central Manitoba, and $83,497 from the Sherritt Gordon. The Gem Lake mine and some prospects produced $7,785. The total output of gold in Manitoba, from the first recorded production in 1917 to the end of 1931, is estimated at 178,669 fine ounces, valued at $3,693,332. The production for 1932 promises to reach a new high record, due chiefly to the stepping-up of tonnage at the Flin Flon plants and the coming into production of the San Antonio mill in May. History The Manitoba Act, constituting Manitoba a Province of the Dominion, was passed in 1870 and provided for the vesting in the Crown of all un-granted or waste lands of Manitoba, as well as for the administration of these lands by the Dominion of Canada for the purposes of the Dominion "subject to, and except and so far as the same may be affected by, the conditions and stipulations contained in the agreement for the surrender of Rupert's Land by the Hudson's Bay Company to the Crown". Included in these waste lands were large areas later prospected and staked out as mineral lands. Up to the year 1912, that vast territory extending from the 12th base line to the 60th parallel of latitude, and from the Saskatchewan boundary to Hudson bay, was part of the District of Keewatin. Although added to Manitoba in 1912, the administration of its mineral lands also remained vested in the Dominion, so that all mineral lands within the Province upon which deposits of gold ore have been found were disposed of and administered by the Mineral Lands Division, Department of the Interior, until the transfer of the natural resources to the Province of Manitoba, on July 15th, 1930.

Jan 1, 1932

By J. Coffin, M. Muinonen, D. Fragomeni, R. Multani, C. Deredin

"Rejection of pyrrhotite from pentlandite is of critical importance to the economics of nickel concentrate production and the main goal of the Strathcona milling operations. A joint team of XPS, Glencore Technology and Strathcona Mill personnel executed a comprehensive program of work to develop and implement strategies for increased Po rejection with focus on challenging ores containing high feed Po/Pn ratios (> 7) and significant hexagonal Po content (> 40% of total Po). This paper describes the team results including minerology, bench-scale flotation tests, and plant validation tests and modeling that have defined the path forward to improving the metallurgical performance and economics of the mill operation. Techniques to quantify hexagonal and monoclinic pyrrhotites were developed at XPS to assess the differences in their metallurgical behavior since their flotation responses are quite different. Mineralogical tools including QEMScan were extensively used to determine mineral liberation, associations, optimum grind size, and nickel deportment into pentlandite, pyrrhotite and non-sulphide gangue. Several reagents/strategies were evaluated during bench-scale flotation testing to significantly increase Po rejection. A significant shift in the Po-Pn selectivity and grade recovery curves was achieved using several strategies including the use of DETA and sodium metabisulfite, and regrind of the rougher concentrate and rougher cleaner/rougher tails.INTRODUCTION The Strathcona Mill is owned and operated by Glencore Nickel – Sudbury Integrated Nickel Operations and has been processing Ni-Cu ores from the Sudbury Basin since 1968 (valuable sulphides: pentlandite (Pn) – (Ni,Fe)9S8 and chalcopyrite (Cp) – CuFeS2). Currently Strathcona Mill receives ore mined from two main sources in the Sudbury area and produces two concentrate streams – a nickel-copper concentrate that is shipped to the Sudbury Smelter and a copper concentrate that is sent to the Fonderie Horne (Glencore Copper, Rouyn-Noranda). The general flowsheet currently used at Strathcona is displayed in Figure 1. It is highlighted by separate feed circuits for regular grade Ni ores and high grade copper ores. The copper circuit has a preflotation stage prior to a rougher-scavenger stage, a copper-nickel separation circuit, and a pyrrhotite (Po) rejection circuit."

Jan 1, 2018

By B. D. Pandey, M. S. Kim, B. S. Kim

The recovery of Sn from used Pb-free solder (Sn, 3~4 % Ag, < 0.9 % Cu, < 1.2 % Pb) has been investigated by electrorefining in sulfuric acid solutions containing small amount of hydrochloric acid. This involved preparation of the anode material by melting and casting the used solder followed by refining. During electrorefining, dendritic tin was deposited on stainless steel cathode. Increasing the amount of hydrochloric acid up to 0.3 mol /L in the electrolyte enhanced the current efficiency to 92.2 % and the enrichment ratio of silver to 94.3 % in the anode slime which was otherwise 84.7% and 81.6 % in absence of HCl, respectively. The electrolyte containing hydrochloric acid has also prevented the precipitation of tin oxide in the bath. In the scale-up experiment using 1.6 kg anodes, 84.3 % current efficiency and close to 100 % Ag enrichment ratio were obtained, while the purity of electro-refined tin was over 99.9 %. The energy consumption of the winning process was found to be 0.151 kWh /kg-Sn which is competitive as compared to commercial tin electrorefining processes.

Jan 1, 2014

By J. R. CAMERON

Gypsum is mined in all Atlantic Provinces except Prince Edward Island. It is generally thought to have been derived from the hydration of anhydrite in areas of minimal drainage. Late Devonian downwarping and crustal oscillation east of the Appalachian fold belt allowed the Windsor Sea to advance and retreat in a depositional trough and deposit about 1,000 m of sediments in Mississippian time, much of which were evaporites. The best areas for further gypsum development are lowland basins such as the Cape Breton Lowlands, the Hillsborough area of New Brunswick and the St. George's Lowlands in Newfoundland, all of which are already sites of gypsum quarries. Nova Scotia's gypsum is mined from the Lower Windsor Group, which is divided into subzones 'A' and 'B'; 'B' provides most of the province's gypsum production. The Atlantic Provinces gypsum industry has markets from the St. Lawrence waterway to the mouth of the Mississippi River.

Jan 1, 1984

By Martin Lebeuf

The phenomena occurring in the cathode and at the cathode surface of aluminum electrolysis cells are very important in regards to cathode voltage drop and cathode wear. In the current study, laboratory-scale aluminum electrolysis cell cathodes were analyzed by X-ray microtomography. This technique allows an excellent visualization of the distribution of different substances, if their respective X-ray attenuation coefficients are different enough. In the current case, the important difference in the mean atomic number between cryolitic bath and graphitic carbon results in good contrasts. The volumetric bath penetration profile, porosity and impurities distribution in the cathode were thus obtained. Furthermore, metallic impurities and bath heterogeneities were observed at the cathode surface. Observations were also made with Scanning Electron Microscopy - Energy Dispersive Spectroscopy (SEM-EDS).

Jan 1, 2011

By M. Kreuh

An investigation of the pressure pulse spectrum generated by the gas dispersion processes in a Peirce Smith copper converter was undertaken via the simultaneous measurement of four tuyeres using high frequency pressure transducers. The data was captured, stored, and analyzed using digital data processing techniques; including power spectral density plots, band-pass filtering, and a principal component analysis (PCA). The process was characterized throughout by a dominant 3 Hz pulse signature attributed to the formation of lateral gas envelopes. In particular, test tuyeres in the tuyere line tended to operate synchronously at the dominant frequency, regardless of operating conditions tested and despite being distributed along the converter. Synchronous behavior is thought to arise from the acoustic coupling and possible resonance behavior of the gas delivery system on the converter.

Jan 1, 2007

By I. Filippova, L. Filippov

"The by-product potential of light rare-earth elements (LREE, La, Ce, Nd) and rare-metals (W, Nb, Sn) within the St Austell kaolin deposits (UK) is related to the kaolinisation process, which liberates the accessory heavy minerals of the host granite in the clay matrix and allows their separation in the waste streams. As a consequence these minerals are pre-concentrated in the micaceous residue which displays relatively high LREE content (around 170 ppm) hosted by monazite which is mainly distributed (up to 95%) in the -100 µm fraction. A combined gravity/flotation concentration flowsheet, starting with classification of the residue into 3 size fractions (+150 µm, 150-53 µm and -53µm) was developed. This study presents the results of the clay-rich -53 µm size fraction beneficiation by flotation using sodium oleate and hydroxamate as collectors.The effect of dispersant addition during de-sliming operations on flotation efficiency was also investigated. The LREE grade in the floated product obtained with sodium oleate increased from 3370 ppm to 5350 ppm and recovery from 30% to 80% with dispersant which is attributed to clay coating. Comparison of flotation performance and Falcon Ultra-Fine (UF) concentration of monazite to previous results obtained with Falcon Semi-Batch (SB) gravity concentrator on the unscreened raw residue clearly shows that flotation of the fine residue is more efficient than Falcon UF and Falcon SB. Indeed Falcon UF produced high recoveries (87-95%) but with almost no enrichment (1.3-1.4 ratios) whereas Falcon SB concentration of unscreened residue produced higher grades (up to 0.6 % LREE) but with low recoveries (17-22 %). These preliminary results show that LREE can be pre-concentrated suggesting that the micaceous residue stream (and the associated tailings dams) could be considered as a potential resource for these metals."

Jan 1, 2016

By F. Chevarin

The reaction of O2 with the carbon anode is considered as the main parasitic chemical reaction affecting Hall-Heroult process anodes. The current study aims at investigating the influence of the microstructure of baked anode on its overconsumption. Samples were removed from different positions of an industrial anode. Density, porosity, Lc and BET specific surface area were measured. The anode reactivity was evaluated based on the weight losses for the samples resulting from the reaction of anode with air at 550°C after 7h. The essential parameters determined to control the air reactivity are closed porosity, Lc and pores with a pore entrance radius of 1.5, 8.5 and 12 p.m. The knowledge of effects of these parameters allows better understanding of the reactivity of anodes and consequently reduction of their overconsumption in electrolysis bath.

Jan 1, 2011

By R. R. Song, Q. Li, H. Xing, X. C. Wei

Geomechanical modelling of fault stability is an important part of CO2 capture and storage (CCS) research program to ensure its viability and long-term safety. Storage of CO2 in deep subsurface reservoirs requires estimates of sustainable fluid pressures that will not induce fracturing or fault reactivation which could cause fault slip. More importantly, fault slip gives rise to seismic waves, which inflict severe damage to the cap rock of the reservoirs and may result in leakage pathways for the buoyant plume and thus compromise the integrity of seal formations. In this study, we generated a numerical model tuned towards conditions usually encountered in the Shenhua CCS demonstration project in Ordos basin. In particular, with the purpose of evaluating the sensitivity of the parameters as well as their relationships with the moment magnitude of the seismicity, a variance-based sensitivity analysis was adopted for importance ranking of the uncertain input parameters of the given model. However, such flow models could involve one or several spatial inputs, for instance, fault dip, distance between fault and the injection well, friction angle of fault, permeability of fault, Young's Modulus of fault, injecting pore pressure and the stress field. Studying the sensitivity to each of these spatial inputs motivated the present work. The results led to the following conclusions: fault depth and fault dip significantly affect the behavior of the fault and the fault slip becomes violent with the fault depth increasing and fault dip decreasing. Furthermore, the results indicate that slip time increases with the fault dip decreasing and decreases with permeability of fault increasing. In addition, the calculation of seismic moment and moment magnitude of an earthquake demonstrates that it rises significantly with the decrease of fault dip and the increase of fault depth, and it decreases with the rising stress field. The results show that variations of the only controllable parameter injection pressure do not show great influence to the fault behavior compared with other geological factors, which imply site selection is extremely important for the CCS projects.

Jan 1, 2015

By O. Hungr, V. Gischig, G. Preisig

Deep-seated landslides are characterized by slow time-dependent movements induced by constant gravitational creep, and periods of acceleration associated with stress changes within the rock and the preexisting fracture network. Natural stress changes are typically caused by seasonal variations in surface temperatures and groundwater pressures, but also by rare and more violent events such as earthquakes. These processes are responsible for cyclic loading and unloading that leads to rock mass damage, fatigue and progressive failure with time, and may explain sudden, unexpected rock slope acceleration phases. In this work, we present a set of distinct-element models to investigate and compare the role of hydromechanical fatigue and seismic fatigue in the history of a deep-seated landslide. Hydromechanical fatigue arises from the fluctuation of pore pressure in fractures accompanying periods of significant groundwater recharge. In alpine areas, there are usually one or two cycles per year associated with snow melt and intense rainfall periods. In the presence of a deep confined aquifer within the rock slope, the amplitude of pressure fluctuations may reach values of 0.25-0.5 MPa. Hydromechanical models considering such pressure changes are able to reproduce observed slope accelerations-decelerations phases. Substantial accelerations may occur even in the absence of a cycle of exceptional amplitude, depending on the current state of fatigue. At a given time, one or more fractures may be critically-stressed, and a small change in applied stress is enough to cause local failure and induce a crisis of enhanced slope acceleration. This is augmented if the rock slope contains planes of weakness associated with its tectonic history, glacial debuttressing, etc. The corresponding behaviour is analogous to laboratory experiments on rock and metal fatigue. Similar fatigue effects have also been proposed for repeated earthquake events in seismically active regions. Unlike hydromechanical stress changes that occur in a more localized portion of the rock slope, those induced by passing seismic waves involve the entire rock mass. Moreover, the frequency and amplitude of stress perturbations due to earthquakes are different than those induced by pore pressure variations, although both likely contribute in combination to the degradation and progressive failure of large deep-seated landslides when both are present. The results presented illustrate that: (1) assessment of slope stability near critical infrastructure (e.g., hydroelectric reservoirs) should not only consider static stability, but also failure mechanisms related to fatigue that evolve over time and may result in an apparently stable slope progressing towards a critical state due to relatively small but repetitive stress changes; and that (2) characterization of fatigue processes affecting a deep-seated landslide requires multiparametric continuous monitoring at different observation points.

Jan 1, 2015

By G. W. H. Norman

"During the past few years emphasis has been placed on the importance of major faults, fault zones, and associated structures in localizing ore deposition. This interest has developed partly through experience in mining camps in other parts of the world, and partly by the discovery of such structures associated with ore deposits in the Abitibi region, northwestern Quebec. The recognition of these structures has been brought about chiefly by detailed mapping that has been gradually extended along most of the southern gold belt of Quebec and across adjacent parts of Ontario. In the Chibougamau region of northern Abitibi, progress has been made in mapping major faults by using aeroplane photographs with a scale of about 1,000 feet to 1 inch for field mapping. These studies have shown that many large faults occur in the Abitibi region; also that there is a relationship, direct or indirect, between faults and mineral deposition. The faults are, however, of more than one type and age, and this should be clearly appreciated in any planned programme for prospecting this great region adequately.Geology of the Abitibi RegionGeneral GeologyFaults of more than one age and type occur in the Abitibi region. In order to appreciate some of the age relationships of the faults, a brief summary of the historical aspects and major structural features of the geology (fig. 1) is necessary. These historical aspects may be briefly summarized in chronological order as follows:(1) Accumulation of Archæan lavas and associated pyroclastic rocks, either alternating with, or essentially followed by, deposition of sedimentary rocks, and interrupted at least once by local and perhaps regional folding and erosion."

Jan 1, 1954