Search Documents

By M. Solomon

Giant, sediment-hosted lead-zinc deposits in northern Australia fonned during development of Mid-Proterozoic extensional basins that overlie Lower Proterozoic basement. The basement in the Mount Isa area, exposed by folding and faulting, contains fractionated, high-heat-producing granites. These granites generate heat at a rate of about 6",Wm-3, probably sufficient to fonn giant lead-zinc deposits either by (a) driving episodic convection of saline basement and basin fluids for periods of IOS to 106 years at temperatures of about 230°C, or (b) heating basin fluids moving under the influence of topographic relief or fault movement. The presence or absence of such granites may form a vital component of the genetic model. Ore-fonning fluid flow was probably initiated by continent-scale, extensional basin fracturing.

Jan 1, 1992

By M. Solomon

Abstract -Giant, sediment-hosted lead-zinc deposits in northern Australia formed during development of Mid-Proterozoic extensional basins that overlie Lower Proterozoic basement. The basement in the Mount Isa area, exposed by folding and faulting, contains fractionated, high-heat-producing granites. These granites generate heat at a rate of about 6 ?Wm-3, probably sufficient to form giant lead-zinc deposits either by (a) driving episodic convection of saline basement and basin fluids for periods of 105 to 106 years at temperatures of about 230°C, or (b) heating basin fluids moving under the influence of topographic relief or fault movement. The presence or absence of such granites may form a vital component of the genetic model. Ore-forming fluid flow was probably initiated by continent-scale, extensional basin fracturing.

Jan 1, 1992

By L. A. Clark, G. H. R. Burrill

"Most unconformity-type uranium deposits in Saskatchewan occur within a few tens of metres above and/or below the basal unconformity of the 1,45-b.y. Athabasca Sandstone. Graphitic basement rocks coincident with post-Athabasca faulting or brecciation at or near the unconformity are important in localizing uranium deposits which form as tabular, ribbon-like bodies with grades averaging over 2 per cent uranium and containing up to 50,000 tonnes UJOs. Some of these deposits have similar contents of nickel and arsenic.In the genetic model proposed to explain these deposits, traces of uranium were leached from the sandstone and weathered basement rocks by oxidized formation waters sweeping through the sandstone and along brecciated faults. Over basement meta-petites, a thick clay regolith adsorbed uranium from the solution. Thus fixed, the uranium was reduced through an indirect reaction with graphite, possibly involving methane. The clay mineral surfaces were thus continuously cleared to allow further adsorption. Basement faults localized along weak graphitic units were re-activated, offsetting the sandstone formation, probably at the time of an early uranium deposition about 1.2 b.y. ago, and served as vents for spent ore solutions. Fluid convection was induced by topographic relief and/or crustal heating from radioactive decay in basement plutons or mantled Archean domes with uranium and/or thorium contents a few ppm above those of adjacent rocks. Heat from radioactive decay within the incipient uranium deposit would develop in about a million years. The self-generating convection cell would continue uranium deposition until all permeability was plugged by minerals. In some instances, convection was re-initiated after subsequent faulting and brecciation. While some deposits were further enriched, heavy flows of oxidized fluids re-dissolved and partially depleted other uranium deposits.The East Alligator Rivers uranium deposits in Northern Territory, Australia, occur within Middle Proterozoic quartzchlorite and quartz-muscovite schists overlain by sandstone. Highest grades occur in silicified breccias where carbonate beds were leached out. Mineralization ages are both pre- and post-Kombolgie Sandstone, but, to date, no significant uranium mineralization has been encountered in the sandstone. There are many general similarities with Saskatchewan deposits, but important differences in detail."

Jan 1, 1981

By w. w. Milde

"Since its startup in 1975, the Rabbit Lake mill has been modified (0 process both increased tonnage and higher grade ore. Ore initially came from the Rabbit Lake pit . In 1985, a major mill expansion was commissioned to allow treatment of B-zone pit ore, which is mineralogically and metallurgically different fromRabbit Lake pit ore.Mill modifications, and the changing ore characteristics and processing targets which made them necessary, are described. Mill LocationThe mill complex, shown in Figure I, comprised of milling facilities, acid plant, power generation , warehouse and administration offices, is located approximately 1.5 Ian south of the Rabbit Lake pit, and about 8 Ian southwest of the B-zone open pit mine.Original Milling CircuitOre feed to the mill commenced June 10, 1975. The mill was designed to process 1500 tonnes per day , 483 000 tonnes per year with an average grade of O.44OJo Ups and an annual production of 2000 tonnes UPs' Run-of-mine ore was dumped directly onto a 60 em square opening grizzly. Oversize was broken with an Ingersoll-Rand hydrauli c rock breaker. Minus 60 cm ore was fed to a 6 m diameter by 1.8 m long Hardinge semi-autogenous (SAG) grate discharge mill. Mill discharge was screened over a Tyler double-deck vibrating screen, with screen oversize returned to the SAG mill feed chute via conveyor belt. Screen undersize (minus 2.4 mm) was pumped to 51 cm diameter Krebs cyclones in closed circuit with the SAG mill. Cyclone overflow (about 50% minus 74 micron) was thickened to 55% solids in a 30 m diameter neutral thickener .Thickened pulp was stored in two mechanically-agitated wood stave tanks (5.5 m diameter by 6 m high), to which sulphuric acid was added to obtain a pH range of 1.5 to 2.0. The fmalleaching was carried out in five more identical tanks. Sulphuric acid and sodium chlorate were used to maintain a pH of 1.5 and a terminal emf of -450 to -500 mV. Steam sparge was utilized to obtain a temperature of 45°C."

Jan 1, 1989

By Rod Maclean, George Stewart

"This paper covers the planning, development, and mining of an underground pillar complex using a bulk mining method. To achieve the long-term goal of continually improving our operating processes, all cut-and-fill and undercut-and-fill workplaces at Thompson Mine have been evaluated for their conversion potential to the bulk method referred to as VerticalBlock Mining (V.B.M.).Since December 1979, conversion has occurred to the extent where 80% of the ore hoisted is mined using Vertical Block Mining (V.B.M.).Productivity and profitability have been substantially improved by converting to this bulk method, especially in pillar areas.IntroductionThompson Mine is a 6000 ton per day underground nickel mine located 3 miles outside the City of Thompson, 400 air miles north of Winnipeg . The mine has two shafts, T-l and T-3 (Fig. 1). The T-l shaft is 4427 feet deep with the deepest mining taking place on 4000 level. The T-3 shaft, which is the area of this presentation, extends to a depth of 2607 ft with the deepest operating level at 2400 ft. The two shafts, some 10 000 ft apart, are connected underground on numerous levels. The ore mined at T-3 is trammed on 2400 level to the T-I main ore pass and hoisted through the T-l shaft. Eight hundred and fifty thousand cubic feet of fresh air per minute ventilates the mine.The 1400 level 310 pillar complex is located in the T-3 mine area. There are six rib pillars, two crown pillars and one main pillar (boundary pillar between cut-and-fill stopes) within the complex (Fig. 2). The majority of the ore in this area has been mined using mechanized cut-and-fill techniques .Undercut-and-fill mining was the method originally planned to recover these pillars. It is slow, labour-intensive, and requires extensive use of timber during the mining cycle. The extraction drifts in the area are heavily timbered due to their proximity to the ore and the age of the facilities. Increasing drift maintenance costs and the successful mining of two main pillars with V.8.M. techniques provided the stimulus to review the mining plans for this area."

Jan 1, 1988

By J. H. Ambrose

Introduction The copper smelter of the Hudson Bay Mining and Smelting Company, Limited was constructed to handle the concentrates produced by the concentrator, the residues from the zinc plant, concentrates from Sherritt-Gordon Mines, Limited, and other custom material that might be available. Construction work was started in 1929 and the first concentrates were smelted in November, 1930. From that time until June, 1931, the operations were more or less of an experimental or tuning-up nature. In designing the smelter, it was believed the following tonnages would be available for smelting per day: Copper Tons Content H. B. M. & S. Co. concentrates 331 14.0 per cent H. B. M. & S. Co. zinc plant residues 77 2.5 per cent Sherritt-Gordon concentrates 200 20.0+ per cent Consideration was given to wet-smelting the charge, but, in order to give greater flexibility to the operation, it was finally decided to roast the concentrates before smelting. Briefly, the smelter equipment consists of three Nichols-Herreshoff roasters, one reverberatory furnace, two Peirce-Smith converters, a Walker casting wheel, and a four-unit Cottrell plant, two units' for the roaster gases and two for the converter gases. A general plan of the smelter is shown in Figure 1. Prior to the commencement of smelter operations, a stockpile of about 9,000 tons of concentrates had been built up by the concentrator and the old pilot-mill. The zinc plant was in operation, but the equipment for drying the residues at the smelter had not been completed. Sherritt-Gordon did not commence their shipments of concentrates until April, 1931. The only flux available was barren sand from a pit ten miles south of Flin Flon, adjacent to the railway. Several small deposits of metal-bearing siliceous ore had been discovered in the district, but none of these were sufficiently large to be considered as a source of smelter flux. At the beginning of March, 1931, the entire stockpile of concentrates had been consumed, and available tonnage for smelting was limited to the daily production of the concentrator.

Jan 1, 1935

By C. B. Webber, L. S. Diaz

"The paper presents the approach taken by Craigmont Mines to grinding circuit control. A detailed description is given of a fully automatic control system which bases its control actions on the continuous measurement of particle size in the cyclone overflow stream. The control system holds a specified particle size in the cyclone overflow, and grinds rod mi 11 ore feed at increased rates. The principles of operation of the system used for continuous measurement of particle size are described, end the improvements in mill throughput and copper recovery over several months of continuous operation are presented.INTRODUCTION Craigmont Mines Limited is located in the south-western interior region of the province of British Columbia, approximately 230 road miles north-east of Vancouver, and ten miles west of the town of Merritt. A moderate climate, good roads and service facilities provided by the Canadian Pacific Railway, Inland Natural Gas Company, and the B.C. Hydro and Power Authority, have provided a very favorable mine and plant site.The preliminary metallurgical design of the Craigmont mill was based on the test results of samples obtained from the original 2500' level drift during 1959. Pilot plant runs and other research testing for design pur¬poses were conducted at the Canadian Exploration Ltd. Laboratory, at Salmo, B.C. The design flowsheet was altered in progressive stages from 2,000 to 3,000, and finally 4,000 tons per day as the ore reserves became better defined. Construction work on the 2,400' level mill site commenced in late 1960. The official opening of Craigntnt Mines Limited took place on September 15, 1961, a little over two years from the time of the metallurgical assessment of the original ore samples.Mill throughput to date has varied widely both on a daily and a monthly basis, due to the varying hardness of the mine ores. The grindability af the ore appears to be related to the oxide iron content, which varies from lows of 9% to highs of 20%. Daily tonnage has ranged from 5,000 tons per day with 10% iron in the feed, to 6,000 tons per day with 20% iron feeds."

Jan 1, 1973

By Simon P. Fricker

Gold drugs have been used for the treatment of rheumatoid arthritis since the mid 20th century as disease-modifying antirheumatic drugs (DMARD) class. Methotrexate is often the preferred DMARD, and with the advent of new therapies gold drugs are now used infrequently. Since the introduction of auranofin in 1985 there has been no new clinically approved gold drug. In spite of this apparent lack of progress there has been a great deal of interest in the use of gold compounds for cancer therapy and early promising indications were achieved with a gold phosphine complex [Au(dppe)2]Cl. This compound was not entered for clinical trials, however, due to problems with cardiotoxicity highlighted during pre-clinical toxicology studies. Gold(III) is isoelectronic (d8) with platinum(II) and likewise forms square planar complexes. It is therefore tempting to speculate that such complexes would have similar antitumor activity to cisplatin. In order to stabilise the gold(III) oxidation cycloaurated complexes were synthesised with a single mononegative bidentate ligand, damp, (2-[(dimethylamino)methyl]phenyl), and two monodentate anionic ligands e.g. Cl or acetate. The damp ligand forms part of a five-membered chelate ring. The monodentate ligands are readily hydrolysed and are available for substitution. These compounds had limited anti-tumor activity in in vivo against human tumor xenografts. Mechanistic studies indicated that these compounds had a different mechanism of action to cisplatin. An alternative molecular target for these compounds is biologically important thiol-containing molecules such as the cysteine protease cathepsin B. Modifications were made to the Au(III) damp structure to give compounds with a six-membered chelate ring. These compounds were shown to be inhibitors of cathepsin B. Compounds were also tested for cytotoxicity against a panel of human tumor cell lines. Three compounds were selected for further evaluation against a human colon tumor xenograft. The compounds showed modest anti-tumor activity but with no marked improvement over the parent Au(III)damp complexes. Initial indications are that Au(III) compounds targeted against disease-specific thiol-containing biological molecules have potential as drugs, particularly for cancer. However, further work is required to produce a target-specific drug with a suitable pharmacological activity and toxicity profile.

Oct 1, 2003

By G. Avramovic-Cingara

Grain boundary characteristics and microstructural evolution are analyzed in a comparative study using orientation imaging microscopy (OIM/SEM) and transmission electron microscopy (TEM/SAD). The subgrain sizes and misorientations were determined by the OIM for aluminum deformed in torsion to equivalent strains between 0.2 and 4 over the temperature ranges of300-600°C and strain rates 0.01-1 s". The OIM gives clearer evidence of boundaries with high misorientation than does TEM, but it overestimates their frequency b y missing boundaries less than 1 0. T EM more clearly reveals low-angle arrays of widely spaced dislocations resulting in finer subgrain sizes than those indicated by OIM. The evidence supports a mechanism combining dynamic recovery (DRY), deformation band formation with permanent boundaries and geometric dynamic recrystallization (gDRX) in contrast to the hypothesis known as continuous dynamic recrystallization (cDRX).

Jan 1, 2004

By W. M. Armstrong, John A. H Lund

The paper describes an investigation of some of the tensile properties of single crystal vanadium, poly-crystalline vanadium and polycrystal-line tantalum, in the range of: W°C to -196°C. Techniques employed in the preparation and testing of specimens are discussed in detail. Some results of determinations of the temperature dependence of yield stress and ductility are given, and discussed in terms of the Cottrell-Bilby Theory of yielding. At subnormal temperatures, all the body-centred cubic transition metals in the Periodic Table exhibit; a) the "yield phenomenon" in tension, b) a strong temperature and strain rate dependence of yield stress, and c) a large decrease or complete loss of ductility. The yield phenomenon (existence of an upper and lower yield point) has been explained by Cottrell and Bilby ( 1) in terms of the dislocation-locking effect

Jan 1, 1961

By Cesar H. Oboni

The development of specific risk-based methodologies to guide and prioritize clearing decisions in countries contaminated by Unexploded Ordnance and Land Mines (generically defined as Explosive Remnants of War: ERW) either at country-wide scale or road-network-scale was used in an unexpected way when a large mining company asked Riskope (www.riskope.com) to develop a multi-modal transportation network risk assessment plan, which included ocean going vessels, ports, wharves, railroad, trucking and other modes of transportation. What had been a first-in-the-world attempt in the humanitarian landmine clearing industry turned out to be extremely useful and equally innovative in the extractive corporate world. Instead of a country contaminated by man-made hazards such as Explosive Remnants of War (ERW) we were now dealing with a very complex multi-modal transportation system afflicted by all sorts of potential hazards from quakes to climate change, sabotage to labour strikes, and vulnerable infrastructures to potential energy crises. Interestingly enough the method developed to deal with ERW risk based clearing was also capable of solving the transportation risk evaluation problem, after necessary customization. This paper shows how ?out of the box? thinking and industry cross dissemination can bring significant evolution and a competitive edge even to unexpected areas of the world-wide mining industry. The results of the logistic system risk assessment shed new light on the management of the system, changed the way insurance coverage was purchased, and led to significant potential cost reductions in a period of global recession.

May 1, 2010

By Fathi Habashi

Extraction by organic solvents is a chemical process in which metal species in the aqueous phase react with an organic reagent to form an organometallic com- plex, thus, the metal species leave the aqueous phase and enter the organic phase from which it can be stripped back in the aqueous phase to obtain a pure and a concentrated solution. The metal in the organic phase is not bound to carbon atoms as in organometallic compounds but to oxygen, nitrogen, sulphur, or hydrogen by a co-ordination (dative) bond (Habashi, 1999).Solvent extraction was used for the first time in hydrometallurgy in connec- tion with the special and urgent materials requirements of nuclear energy during World War II. A plant was constructed in the United States for the preparation of high-purity uranyl nitrate solution. In this plant, the yellow cake (a high-grade sodium or ammonium uranate) was dis- solved in HNO,, and uranium was selec- tively extracted by ether then stripped by water to give a concentrated solution of pure uranyl nitrate. This was gradually followed by developing methods for other high-priced metals such as plutonium, thorium, niobium, tantalum, zirconium, hafnium, boron, beryllium, and molybde num. The second step took place in the 1960s when solvent extraction was applied for the first time to extract a rela- tively cheap metal-copper. At present, solvent extraction technology is wide- spread, well accepted, and highly efficient. Solvent extraction had its origin in the discovery, by Christian Friedrich Bucholz (1770-1818) in 1805, that uranyl

Sep 1, 1999

By E. Tulcanaza

Mining companies normally establish exploration and research programs originated with actions in embryonic stage. At their early stages of development, these exploration and technological activities are subject to uncertainties that need, first, to be resolved, deciphered or, at least, mitigated for information reporting; and later, for valuation reporting. Under these circumstances, these exploration activities follow a sequence of development phases that range from exploration work to the profile, conceptual, and finally to basic engineering phases and construction. For information reporting, the International Template for Reporting of Exploration Results, Mineral Resources and Mineral Reserves integrates the minimum standards being adopted by the relevant professional bodies in Australia, Canada, South Africa, Chile, USA, UK, Ireland, and other European countries which set up the Committee for Mineral Reserves International Reporting Standards (CRIRSCO, www.crirsco.com). These standards are based on the progressive collection of relevant information to reduce present and future uncertainties over time under a context of transparency, materiality, and technical competence. For valuation reporting several procedures have been disclosed and applied. However, in the last decades financial instruments such as real options, decision analysis, and games theory have developed into a niche of great potential for mine valuation applications. The objective of this paper is to provide a summary of the information reporting standards prepared by the Chilean National Commission for the Qualification of Competent Persons in Mineral Resources and Mineral Reserves and show a procedure and an application of real options to the valuation of the sequential development phases of a mine asset from the exploration stage through up to full development.

Jan 1, 2007

By D. M. Maijer, S. M. Mohseni, A. B. Phillion

The microstructure evolution kinetics of aluminum alloy B206 during artificial aging has been investigated using non-isothermal calorimetry. A combination of differential-scanning calorimetry (DSC) and tensile tests have been utilized to develop an Avrami model to predict the precipitation kinetics as a function of the thermal processing parameters. The Avrami coefficients, found based on a Kissinger analysis, compare well against those reported in the literature for aluminum-copper alloys. The rapid precipitation kinetics predicted by the Avrami model at temperatures higher than 200°C were assessed through a qualitative comparison against hardness measurement results. In contrast to the continuous hardening observed at 150°C, the material softens with continuing heat treatment at 250°C resulting in an overaged state. This can be attributed to the rapid precipitation kinetics at this temperature, leading to the termination of the precipitation-hardening effects at early stages of artificial aging.

Jan 1, 2015

By R. H. Nafziger

A novel process has been developed for preparing directly workable steel ingots from prereduced iron ore pellets by a two-stage process. The pellets are continuously charged into an electric arc furnace, where molten metal is separated from the gangue. The molten metal flows out of this furnace through a hollow nonconsumable graphite electrode immersed in a molten flux in an electroslag furnace. The molten metal solidifies on a continuously withdrawing base plate to form the ingot. A variety of standard carbon and alloy steel ingots . free of porosity , were produced using suitable decarburizers and ferroalloy additions. Some advantages of the two-stage process include: (a) consumable electrode fabrication is eliminated; (b ) no expensive deoxidizers are required; (c ) the uncontaminated electros lap flux can be reused; (d) energy consumption averages 25% less than in a conventional electric arc - electroslag operation ; and (e) the operation is continuous.

Jan 1, 1977

By R. F. Robertson

"Adsorption isotherms of hexyl mercaptan vapour on synthetic sphalerite, zinc sulphide and zinc oxide were de-termined with a gravimetric McBain-Baker micro balance incorporated in the B.E.T. apparatus. Isotherms are given for hexyl mercaptan on synthetic sphalerite at 25°C, 0.5°C and 50°C; on zinc sulphide at 25°C and 1.5°C; and on zinc oxide at 25°C. All these isotherms are sigmoidal, with a definite change in slope at or close to the mono-layer. The amount of mercaptan adsorbed below the monolayer increases almost linearly with relative pressure to P/P0 = 0.8.Above this value, the amount adsorbed increases very rapidly with relative pressure. Hysteresis loops appear in the isotherms for all adsorption-desorption cycles. These loops are completely reversible. It is not possible to desorb the mercaptan monolayer from any of the adsorbents, even at elevated temperatures."

Jan 1, 1966

By C. Blawert

The corrosion properties of the skin and the bulk of semi-solid processed and high pressure die cast AZ91 alloy were studied in 5% NaCI solution by (a) analysing the corrosion morphology, (b) measuring electrochemical polarization curves, (c) performing electrochemical impedance spectroscopic measurements, and (d) immersion tests at constant pH-values. Using XRD, LM, SEM and EDX to evaluate the microstructure of skin and bulk specimens, the corrosion results were related to the microstructures of the particular alloys. However, microstructure and corrosion performance were found to be similar for both production processes, and only slight but distinct differences were found. Generally, the skin corrosion properties are inferior to those of the bulk, with the exception of the high pressure die cast AZ91 alloy, where the finer microstructure of the skin layer exhibits a better performance as showed by impedance studies and confirmed in long term immersion tests.

Jan 1, 2004

By G Anders

The effectiveness of two types of powder used in long-wall slashing was compared. The evaluation of the results can serve as a good example of how the application of statistical methods to underground test data can help to minimize the number of tests to be carried out. The conclusions are stated concisely, including a definite assessment of the reliability of the tests. Introduction AN assignment at the Algom Nordic mine called for a performance comparison between 70 per cent Cilgel B and 75 per cent Dygel in longwall stope slashing, particularly taking into account, in both cases, the build-up of bootlegs as dependent on hole deviation. Stopes were usually 8 to 10 ft. high and inclined at about 17 degrees. Starting from a raise, they were widened by consecutive longwall slashes to 60 ft., and, al-lowing for drift pillars, were approximately 300 ft. in length along the incline.

Jan 1, 1964

By W. R. Middagh, R. M. Garvey

"Phosphate rock is shipped by boat from Florida to Vancouver, B.C., where it is unloaded and stored in a 50,000-ton silo. It is shipped from Vancouver in 100-ton hopper cars in 80-car trains to Fort Saskatchewan. Both the ship and the hopper cars are on a back-haul with potash. The rock cars are unloaded at Fort Saskatchewan at a rate of approximately 4 cars per hour. The rock is stored in three concrete silos, 40 ft in diameter by 110 ft high, which hold 18,000 tons of recoverable rock with 2,000 tons dead space. The rock is reclaimed from the silos by gravity and fed to the phosphoric acid plant by remotely operated conveying equipment.Problems encountered in the operation include scheduling the rock shipments, contamination of the rock with potash, and handling the 80-car trains both in Vancouver and Fort Saskatchewan."

Jan 1, 1968

By John S. Stevenson

ZEBALLOS is a relatively new mining camp. It is on the west coast of Vancouver island, approximately 195 nautical miles northwestward from Victoria. Previous to 1934, a small amount of placer gold had been recovered from the Zeballos river and tributary creeks. However, it was not until the winter of 1934-35, when shipments of high-grade gold ore were made from the property of the White Star Gold Mines, Limited, that lode gold mining really began. Since then, several new mines and many promising prospects have been found. Milling in standard sized mills only commenced late in 1938, when the 75-ton mill of Privateer Mines, Limited, and the 50-ton mill of Spud Valley Gold Mines, limited, were first turned over. The most striking feature of the camp is the high-grade quality of the ore as usually mined. At one property, the ore along a drift 650 feet long has ranged from 5.8 ounces per ton to 17.5 ounces, over average vein-widths ranging from 8.3 inches to 14.5 inches in selected blocks along the drift. One . high-grade shipment of 196.6 pounds of ore from the same property contained 142.877 ounces of gold. The present paper deals only with that part of the area in which mining operations are most active, namely the main Zeballos River valley and its tributaries, Spud and Goldvalley creeks. During the summer of 1938, prospecting was carried on beyond this circumscribed area. The geology and early developments in the area have been described in the following reports: (1) CLOTHIER, G. A., Annual Report of the British Columbia Minister of Mines, 1929, p. 376; 1930, p. 441; 1932, p. 205; and 1933, pp. 252-254. (2) GuNNING, H. C., Geological Survey of Canada, Summary Report, 1932, Part A-II, pp. 29-50, Zebaltos River Area, Vancouver Island, B.C. (3) STEVENSON, John S., Annual Report of the British Columbia Min-ister of Mines, 1935, pp. F-38-40. ? ( 4) BANCROFT, M. F., Geological Survey of Canada, Memoir 204, 1937, Gold-Bearing Deposits on the West Coast of Vancouver Island Between Esperanza Inlet and Alberni Canal. (5) STEVENSON, John S., British Columbia Department of Mines, 1938, Lode-Gold Deposits of the Zeballos Area. (6) MAcDoNNELL, G. F., The Privateer Mine, Zeballos; The Miner, Van-couver, B.C., December, 1938.

Jan 1, 1939