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Although the pattern of metamorphic zones south of the Thackaringa-Pinnacles Fault is much obscured by polymetamorphism, displacement of the orthopyroxene isograd by the fault agrees with the displacement of a horizon of "banded aplite" mapped by Andrews (1922). A dextral transcurrent component of 20,000 ft is indicated.INTRODUCTIONThe east-west Thackaringa-Pinnacles Fault (Andrews, 1922; King and Thomson, 1953), one of the major geological structures in the Broken Hill district, New South Wales, cuts across the general north-easterly strike of outcrops and fold structures of the Willyama Complex. The degree of shearing and recrystallization in its unusually wide crush zone and the manner in which adjacent rock units and structures have been dragged into conformity with its strike denote considerable movement on the fault. Information concerning the nature of this movement is of critical importance in the search for possible continuations or repetitions of lead-zinc mineralization south-west of Broken Hill.A transcurrent movement of 20,000 ft, with the southern block moving west, was estimated by Andrews (1922), who correlated prominent outcrops of "banded aplite" at The Pinnacles (north of the fault) and Big Hill (south of the fault). Displacement of this order, however, does not seem sufficient to explain the extent and character of the fault zone. Recent chemical and petrological studies of the banded aplites at The Pinnacles and Big Hill by Vernon (19B1) confirmed their similarity, but indicated an origin by metasomatic replacement of pre-existing folded and metamorphosed rocks. This raises the possibility that some...

Jan 1, 1965

By Schwartz M.

Respect for mining in Botswana is long-standing. This article looks at Africa's most transparent mining regime and some of its ambitious plans. Botswana's mining industry value is forecast to average 5.2% growth from 2014-2018 with solid growth for the diamond sector and acceleration of coal production. Respect for the country's mining regime is maintained in the Fraser Institute 2014 annual survey where Botswana occupies the 26th position of 122 administrations. Botswana's transparency is illustrated by Mupane gold mine near Francistown, Ghaghoo diamond mine in the Gope area and the Morupule coal mine

Mar 1, 2015

This paper summarizes the progress of geological exploration at North Broken Hill Ltd.The North Mine orebodies occur in knots of minor folds on a simple limb structure which is itself highly folded, giving rise to two distinct orebodies pitching N. at av. 42° down to 2,920-ft. level, where the pitch steepens to near vertical as a result of complementary shear movement on the Globe-Vauxhall Crush Zone.The lack of adequate marker beds and top and bottom relations makes the resolving of the complex structural environment of the orebodies most difficult.To test the deeper ground of each side of the De Bavay Fault on the 2,600-ft. level the footwall drive was extended 3,556 feet and over 20,000 ft. of drilling completed from three transverse fans, only one of which intersected the orebodies due to steepening of pitch.The problem of locating the North Mine orebodies N. of the DeBavay Fault remains speculative because the exact position of them S. of the fault is still unknown. Exploration beyond the fault in the search for ore had two lines of mineralization to consider, an eastern one through Cosgroves-Round Hill, long regarded as the continuation of the main lode, and a western one passing through Silver Hill Silver Peak.From surface 45,000 ft. of drilling was completed in five sections, establishing that the structure was dominantly synclinal with a flatdipping E. limb, the W. limb and adjoining structures being involved in the Globe-Vauxhall Crush Zone. Mineralization, though weak, was remarkably persistent but the economic mineralization exposed at surface has not persisted with any continuity.Deep exploratory drilling below the bottom level (3,370 ft.) has established high-grade ore to a depth of 4,095 ft. and also has proved its existence within the Globe-Vauxhall Crush Zone.INTRODUCTIONThis paper summarizes the progress of geological exploration at North Broken Hill Limited from the inception of the Geological Department in 1941 until the end of 1955. The writer has drawn freely on departmental records for the period prior to 1947.

Jan 1, 1956

By V. Izaxon

Current practice in mining frozen, underground placers is to support the mine openings by leaving remnant pillars, which are kept frozen to maintain their stability. These pillars may be partially extracted depending on mining conditions, but this practice may be risky, and roof falls are common. Instead of allowing the mined-out areas to cave, the extracted entries could be filled with waste material, which would then be frozen, using cold ventilation air. A finite difference model for analyzing the effects of various parameters on the freezing of backfill in underground mines in the Arctic has been developed and tested. The model also accounts for properties unique to a frozen rock mass, including those that change with temperature. Examination of the characteristics of ice-cemented mining waste materials as backfill indicates that with proper engineering control, a backfill system can be designed for use in production mines. The system will allow increased extraction ratio while maintaining the stability of underground openings with minimum heat impact on the surroundings. These simulated results establish the relationships among the strength, the temperature, and the freezing characteristics of a given material. When coupled with site observations these relationships will facilitate the optimal design of ore pillar recovery methods.

Jan 1, 2004

Les Mines Inmet ? La Division Troilus exploite une mine d?or à ciel ouvert depuis 1996 et produit un concentré de cuivre. La Division Troilus est localisée à 175 KM au nord de la ville de Chibougamau? au 51 parallèle.

Feb 1, 2008

By E. R. Maize

This report is t e second of s series on roof movement in coal mines. The first (R. I. 3355)4/ dealt with convergence of roof and floor and movement of the surface accompanying and following extraction in a mechanized mine in which retreat of rib lines was rapid. The studies reported herein were made in a mine in which all the coal is loaded by hand, and movement of the rib lines was much slower in consequence. In choosing a site for this work, it was decided that the mine selected should have natural conditions akin to those of the first study and entirely different methods of working. To this end a cooperative agreement was made with the Crucible Fuel Co. through W. J. Whitaker, secretary, for conducting the work in the company?s Crucible mine, operating in the Pittsburgh bed in Greene County, Pa, This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as can be made.

Jan 1, 1939

By P. J. Rowsell, M. D. Waller

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993. The applications of artificial intelligence systems in the upstream petroleum industry are reviewed. Particular emphasis is placed on current and potential applications in drilling engineering. Several recent advances in drilling technology have led to a large increase in the quality and volume of data available. This combined with the escalating cost, particularly of off-shore operations, is testing the traditional reliance on the skill and judgement of rig operators. AI systems offer enormous scope in enhancing and aiding the performance of these operations

Apr 1, 1994

By Malcolm Ross

Fibrous minerals are common in nature but asbestiform minerals are rare. The unique mineralogical characteristic common to all the asbestos minerals is their morphologic form (or habit of crystallization) as polyfilamentous fiber bundles. The individual fibrils within the bundles have a tendency to be very long with a narrow range of diameters and grow with their long fiber axis in parallel orientation to the bundle length. The asbestiform habit imparts to the asbestos minerals sufficient flexibility and tensile strength so that most can be woven into cloth. In the past application has focused on their ability to insulate against the transfer of heat. However, these minerals possess other properties which make them useful in many industrial applications. © 2007 Elsevier Inc. All rights reserved. Keywords: Asbestos; Asbestiform; Fibrous

Jan 1, 2007

Up to 19 chemical parameters were studied in flotation pulps in six Australian lead-zinc concentrators with the aim of obtaining a better understanding of the nature of, and changes in, the chemical environment. This paperdiscusses pH, redox potential, and oxygen concentrations, which were all measured continuously.Two plants operated at natural pH in slightly acid circuit and one at natural pH in alkaline circuit, and pH was stable at all these plants. In two plants varying amounts of cement fill were present in mill feed and pHwas variable. At the other plant pH was controlled with soda ash and lime.Redox potentials became more positive as the pulp passed through the plant. The minimum change was 20 mV and the maximum about 250 mV. Potentials tended to be variable at any point early in the circuit, but were more stable later on. In some plants reagent additions had no noticeable effect on redox potentials. However in the two plants operating in acid circuit the redox potential of .zinc rougher feed was markedly affected by changes in copper sulphate addition rate. Sodium sulphite additions had an effect at other plants.Oxygen concentrations in grinding circuits tended to be low (30 per cent of saturation) and very variable. Flotation was usually conducted in pulps at least 90 per cent saturated with oxygen. Addition of sodium sulphite had a marked effect on oxygen content in one plant, but less effect in two others.Statistically significant relationships were found in some plants between pH and redox potential, redox potential and oxygen saturation, and oxygen saturation and pH.Improved control of copper sulphate and sodium sulphite additions could result from applications of this work.

Jan 1, 1970

By Derek. C. Arnold

In order to meet increasing demands for water supply in the next millennium, the Government of the Hong Kong Special Administrative Region have identified the need for a major new water treatment and transfer scheme. The project now under construction will comprise a 1.2 km long raw water aqueduct, a major new 0.25million cubic metres per day water treatment works (with space for upgrading to 1.2Mm³/d), a 12.1 km long treated water aqueduct and a primary service reservoir. In order to meet increasing demands for water supply in the next millennium, the Government of the Hong Kong Special Administrative Region have identified the need for a major new water treatment and transfer scheme. The project now under construction will comprise a 1.2 km long raw water aqueduct, a major new 0.25million cubic metres per day water treatment works (with space for upgrading to 1.2Mm³/d), a 12.1 km long treated water aqueduct and a primary service reservoir.

Jan 1, 1999

By James A. Mason

The State of California has instrumented numerous buildings, bridges, and dams throughout the state with earthquake recording devices. These accelerometers are strategically placed to measure the response of the structure to a specific seismic event. This comprehensive program enlightens the field of seismic engineering after each earthquake. The Office of Strong Motion Studies, California Strong Motion Instrumentation Program, a sub-branch of the Division of Mines and Geology, provides a professional service unequalled in the world. Within hours of a local earthquake, a preliminary report with the epicenter / hypocenter, structural damage, and time history records are available to all interested parties. The included partial report in the appendix, see section 5.1, is one of the reports that C.S.M.I.P. produced after the Loma Prieta Earthquake of October 17,1989. The diagram on the cover is even of interest. This is a small portion of San Francisco. The values on the diagram are the recorded maximum horizontal ground accelerations at that location in the city. For example, the acceleration at Yerba Buena Island was 0.06g. (The "g" refers to the acceleration of gravity. Thus, a 0.06g acceleration refers to the force, F=m*a, that the structure would experience. For this case, the force would be six percent, 6 % , of the mass of the structure.) Yet, directly on the other side of the Bay Bridge, at Treasure Island, the acceleration was 0.16g. Yerba Buena Island is a natural island composed of hard granular material. Whereas, Treasure Island is a man-made island of imported filled. Here one can see the absorption / transmission difference between hard material, which interact with short seismic wavelengths, and soft cohesive material, which interact with long seismic wavelengths.

Jan 1, 1993

By Quentin Rhoton

To benefit two endangered fish species, waterfowl and other wildlife, and water quality in the lake and downstream, the decision was made to remove levees that had been in place since the 1950s. Because the levee material was mainly dredged up lake bottom peat, it was decided to pare down the sites chosen for breaching with dozers and trackhoes. This material was spread out onsite instead of expensive removal by dumping elsewhere. Because of the instability of the final pared down levees and the lake level being at a ten-year low, it was decided to use explosives to breach four of the sites. After over five months of earthmoving and two weeks of loading holes, the levees were detonated the day before Halloween, 2007. Somehow pumpkins showed up to be part of the explosive activities.

Jan 1, 2009

By G. G. Goble

Dynamic pile testing is now over 20 years old as a routinely applied tool for evaluating driven pile installation. The first test on a cast-in-place pile was performed more that 15 years ago. The research that produced the method began almost 30 years ago. But, questions still arise regarding the appropriate use of this technique so some review is useful. Today a number of methods including dynamic testing all depending in some way on the application of dynamics are in routine use. First, Wave Equation analysis can be used to predict pile driveability before going to the field. The same approach can be used during driving to estimate the bearing capacity based on the blow count observed in the field. Dynamic measurements, on the other hand, can only be used after pile driving has begun. They offer predictions of pile capacity as well as measurements of hammer, driving system, and pile driving performance characteristics. The first part of this paper will be devoted to discussing how the foundation engineer can use these tools. First, a brief review of what dynamic methods actually do. In Wave Equation analysis a numerical model of the hammer, driving system, pile, and the soil is created by the engineer. The hammer is dropped on the pile and using a discrete, dynamic analysis the motion of the individual pile elements is calculated as a function of time. Of course, input information must be supplied by the program user to describe the hammer, driving system, pile, and soil. In the current state of development, the primary problem in input data is with the hammer performance (efficiency) and the soil description. Research may be able to do a better job with the soil data, but hammer performance will always vary from hammer to hammer and is dependent on the affectiveness of the inspection process. Prior to beginning pile driving the Wave Equation analysis supplies the best available estimate of what will happen when driving begins. It gives an estimate of blow count during driving, driving stresses, both tension and compression in the pile, and for diesel hammers, stroke. The selection of the driving system can be checked with the results of Wave Equation analysis and modifications can be made if required. For example, if the blow count at the required capacity was deemed excessive by the contractor a larger hammer could be tried or if driving stresses were too high changes could be made in the cushion or the hammer selection could be modified. All of these modifications are possible with only the cost of a computer run. The primary questions regarding the accuracy and reliability of Wave Equation analysis at this time is with regard to the assumptions made to represent the soil characteristics and the difficulty in predicting hammer performance.

Jan 1, 1993

By F N. Baez

This paper supplements a keynote address prepared for the MassMin 2016 conference on mass underground mining methods, including block, panel, inclined and sublevel caving. It advocates for a new cave mining paradigm that takes advantage of a number of new and disruptive technologies or innovations that have evolved over the last 15 years, some of which were initiated by major mining companies such as Codelco. The paper will address the challenges that the industry will be facing in the future as well as possible solutions. As background, the paper summarises the challenges that the industry has faced in the past and how such challenges were addressed. The author acknowledges that given his more than 30 years of experience with Codelco Chile (operations and corporate), aspects of his intelligent mining concept have no doubt been influenced and have matured during his invaluable time with Codelco also as the Head of Technology and Innovation. In the paper, he uses some of the innovations developed within Codelco and by the Chilean Government to illustrate the concept of ‘intelligent mining’.CITATION:Baez, F N, 2016. ‘Intelligent mining’ – the way of the future, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The AusIMM/AMIC code for reporting Reserves seeks to improve the calibre of professional reporting on this subject. But have they gone far enough? Should the code appreciate that the degree of reliability of estimates required will vary with the type of mining planned? How does one "confirm continuity" as required by the code? The aim of optimum development drilling is to achieve appropriate ore zone definition for acceptable estimates of reserves and their economic extraction. Can this procedure be in conflict with the code? How does it affect finance decisions?

Jan 1, 1989

By G. M. Molinda

Ground Penetrating Radar (GPR) is being investigated for the potential to determine roof hazards in underground mines. GPR surveys were conducted at four field sites with accompanying ground truth in order to determine the value of GPR for roof hazard detection. The resolution of the current system allows detection of gross roof fractures (>63 cm (s1/4 in) zone) or rider beds in coal measure roof. Data quality is not yet sufficient to detect small bed separations or subtle lithologic changes in the roof. Differences in data quality are discussed, as well as suggestions for collecting improved data.

Jan 1, 1996

By G. W. Jones

From evidence made available during the investigation, it was concluded that the first of a series of explosions occurred at 1:15 to 1:20 p.m. September 21, 1951, in an underground vault that housed pressure regulators on the gas-distribution lines that served Brighten. This explosion damaged the pressure regulators and permitted high-pressure gas to enter the distributing mains and individual-service lines. As a part of the gas-distribution system was not provided with means for protection against such excessive pressures, gas gained access to the interiors of many residences in this area and caused a series of disastrous explosions and fires, which took place during a period of approximately 2 hours after the initial explosion in the pressure-regulator vault. Two persons were killed in the first explosion in a residence, and a third person died of a heart attack attributed to the excitement that prevailed during the explosions and fires, Twenty-three persons were listed as injured. Forty-one residences were either destroyed or damaged - 11 by explosion and the remainder by fires, which developed as a result of gas leakage into residences. Fifteen residences were listed as "completely down" or "gutted." Unofficial estimates of property damage ranged from $1,000,000 to $1,500,000. In view of observations made and information obtained during the investigation, recommendations are presented in this report relative to the natural-gas distribution system in Brighton, which may be helpful in the prevention of similar accidents in this and other communities.

Jan 1, 1952

By Marina Carreiro-Silva, Cátia Cardoso, Bruce Shillito, Lisa Mevenkamp, Alastair Brown, Maria J. Bebianno, Juliette Ravaux, Inês Martins, Nélia C. Mestre, S. Sousa Vânia

Mineral extraction activities in the deep sea will expose the local fauna to potentially toxic compounds. However, very few data are currently available on the complex ecotoxicological risks to deep-sea fauna from the potential release of heavy metals, trace metals and Rare Earth Elements (REEs). Nonetheless, this is key information essential to support the regulation of industrial activities in the deep sea. One of the fundamental issues that the MIDAS project will address consists in exploring the concept of whether the existing toxicity test protocols and limits established in shallow-water species are applicable to deep-sea mining. We will detail the specific challenges to recommending exposure limits within the deep sea and show preliminary results of comparative toxicity tests in the shallow-water and in the deep-sea environment.

Sep 1, 2014

By A. A. Smithen

There is an increasing awareness of the importance of including an assessment of environmental liabilities in the preparation of bankable feasibility documents. This means that environmental assessments of proposed, existing and decommissioned mine sites have to be undertaken for the purposes of quantifying environmental liabilities and assessing potential risks. This paper examines the need for considering environmental liabilities before describing the approach adopted in undertaking due diligence studies for the preparation of bankable feasibility documents and some of the difficulties experienced. Finally, some concluding remarks are made and the implications for the mining industry are discussed.

Jan 1, 1999

By W. J. Mcgaughey

A crosshole seismic imaging (tomography) experiment has been carried out in an underground mine in order to delineate waste rock within a massive sulphide ore body. Data comprising 1526 travel time measurements were inverted to yield a compressional wave speed image consistent with, and adding to, knowledge of the extent of the waste inclusions. An effective method of resolving travel time discrepancies measured on reversed ray paths is presented.

Jan 1, 1989