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Deep hydrothermal fluids adjacent to the Alpine Fault move through the brittle-ductile transition to mix with convecting fluids from near surface environments. These tectonically driven fluids evolve mainly from prograde metamorphism at mid crustal depth (ten kilometres) within the ductile regime which has been elevated due to advection and drag on the fault plane. Through the onset of brittle failure and cataclasis within Alpine Fault mylonites, fluid overpressuring results in hydrofracturing and localized implosion. Along the length of the Alpine Fault, hydrothermal alteration varies on most levels (Table 1). There is an observable increase in Fe-Mg carbonate between the Waitaha and Taramakau Rivers (between Ross and Aurthur's Pass, respectively). Field studies concentrate to the north east of the Arahura River, noted for historical mineral wealth. Late meteoric fluids move through cataclasite, brecciated mylonite, and other open fractures. Chloritisation is the major retrogressive phase. Dolomitic hydrofracture veins (Figure 1) within coherent mylonites contain iron and copper sulphides. Notably, the enrichment in Fe-Mg carbonate towards the Alpine-Hope Fault intersection seems to represent a region of enhanced permeability possibly related to shallow seismicity, increased regional faulting, footwall variation, strike-slip dip-slip distribution, and/or topographical anomalies (ie saddles). Isotope studies identifying an 'Inboard Fault Gouge Calcite Zone' correlate to values from the Main Divide region at the headwaters of the Arahura River (Browning Pass-Wilberforce Valley) (Becker et aI, 2000). These correlations are supported by rare arsenic anomalies (avg l06 ppm n = 5, Figure 2) found in both regions which suggest that fluids may be interconnected at depth.

Jan 1, 2001

The Division of Minerals and Geochemistry in collaboration with three mineral exploration companies, Mawson Pacific Ltd, Ramsgate Resources Ltd and Tectonic Systems Pty Ltd commenced a two year research project to investigate the application of remote sensing techniques to exploration for mineral deposits in access of the Yilgarn Block in Western Australia. The project utilizes satellite data such as day and night imagery from the NOAA-AVHRR (National Oceanic and Atmospheric Administration - Advanced Very High Resolution Radiometer) satellite. The recent research with the imagery in the Kalgoorlie, Southern Cross and Mt Magnet regions has highlighted the advantages of the mid infra-red and the two thermal response channels of NOAA-AVHRR for geological investigations. These three channels have the spectral resolution to distinguish stratigraphic units and younger intrusive bodies, and to delineate fracture zones and shear zones associated with Proterozoic dykes. But most important is the capacity to distinguish thermal signatures from geological structure, near-surface outcrop and palaeochannels which have been covered by unconsolidated sediments. The research project applies remote sensing methods including enhanced satellite imagery optimised to the Western Australian environment. It encompasses data from both space and airborne monitoring platforms that have obsreved a significant spectral response for the classification of alteration zone lithologies. It includes the collection of multiseasonal data from areas of interest which is essential both for the understanding of thermal characteristics of important lithologies and for the extrapolation from field work investigation to potential exploration areas. No comprehensive investigation of this type has been carried out within the Yilgarn goldfields.

Jan 1, 1987

By Higuchi K

In this paper, the history of Japanese coal and gas outbursts is presented and circumstances and countermeasures at the time cf outbursts are summarized statistically. Then the present meth- ods for prevention used practically in Japan are introduced. From statistics, it was reconfirmed that Japanese coal and gas outbursts have occur- ed frequently in the district of geological disturbance, symptoms immediately before out- burst occurrence were the phenomena in connec- tion with failure of a coal seam and outbursts have occurred many times when the number of boreholes had not been sufficient to degas. One of the principal protective method adopted in Japan is the large diameter gas drainage boring which also posesses a stress relief effects. There is a tendency to make diameter of borehole larger to increase both stress relief and degassing effects.

Jan 1, 1986

Blasting is at first sight a simple operation. Blastholes are drilled in a suitable pattern, primed, charged with explosives, stemmed and finally the blastholes are connected together to give the appro- priate initiation sequence. In practice the action of the explosive takes place in the interior of an opaque rock mass and only the external faces of the rock mass to be blasted can be easily observed. The mechanisms of blasting cannot be observed directly and must be inferred from observations of the free face and meas- urements of particle movement made by sensors grouted into holes in the rock. Explosives react very rapidly, in some microse- conds and any instrumentation of a blast must have an appro- priate response time. In many mines several rock types can be encountered during production. Several different methods of blasting may be necessary to cope with changes in rock types espe- cially if weak rocks are found in the final limits. This also makes it difficult to be sure of getting a large enough volume of rock to perform a series of reproducible experiments. While there appears to be agreement on the mechanism of blasting it is unlikely that a detailed understanding of how all the variables that can be encountered in practice affect blasting. The ease of assessment of the results of blasting depends on the criteria used. It is easy to isolate, measure and count over- size boulders. It is however difficult and costly to get a complete fragment size distribution. Methods used to assess blasting can vary significantly from site to site and the ways in which data are collected, presented and analysed will vary making compari- son of blasts at several locations very difficult. The definition of an optimum blast can also vary with the type of blasting. The muck-pile profile and fragmentation will be different for a dragline to that for a truck and shovel operation. In order to be able to assess blasting the mechanism has to be understood. Th rock and explosive properties considered rele- vant to blasting can then be determined. This paper discusses the generally accepted mechanism of blasting. The on-site observa- tions to assess blasting are-then listed. The mechanism of blast- ing can also be modelled and the use of modelling to optimize hlaetina ie thPn Aiernccarl

Jan 1, 1988

During the past decade geopolymer technology has emerged as a possible solution for the effective stabilisation and solidification of waste materials. Amorphous to semi-crystalline geopolymers form by the co-polymerisation of individual alumino and silicate species, which originate from the dissolution of silicon and aluminium containing source materials at a high pH in the presence of soluble alkali metal silicates. It has been shown previously that geopolymerisation can transform a wide range of waste alumino-silicate materials such as fly ash and blast furnace slag into building and mining products with excellent chemical and physical properties, including high compressive strength as well as fire and acid resistance. These chemical and physical properties suggest that geopolymeric matrices derived from waste materials are well suited for environmental and other applications such as the encapsulation of mine tails, the immobilisation of heavy metals and also the fabrication of structural products. The current challenge is to demonstrate that a wide variety of natural Al-Si minerals could serve as potential source materials for the synthesis of geopolymers. Moreover, it should be shown on a large commercial scale that it is possible to encapsulate waste materials into the geopolymeric structure without compromising the chemical and physical properties of the final product for the desired application.

Jan 1, 2000

By Mudge S. T

Tin mineralisation occurs at Renison Bell, near Zeehan in Tasmania, as a group of cassiterite-bearing massive pyrrhotite bodies in Cambrian sedimentary rocks. Mineralising fluids from the underlying Pine Hill Granite have replaced carbonate rocks with massive sulphides and cassiterite. The discrete blocks of massive pyrrhotite have high density and high magnetic susceptibility contrasts with the comparatively barren country rock. They are strongly remanently magnetised and are excellent geophysical targets. A detailed geophysical model of the mine was created from a database comprising 1:2500 scale geological mapping and geological logs of approximately 4000 drill-cores. The model comprises 93 parallel cross-sections, each 1.5 km long, spaced 20 m apart. Each cross-section is comprised of up to 150 polygons which represent all known individual rock types and orebodies. The magnetic response of the model was computed and the residual between the model and the observed response, measured by a low-level helicopter magnetic survey, revealed several anomalies unaccounted for by the model. Drill testing of these anomalies led to the discovery of several hitherto unknown massive sulphide occurrences. Surface gravity data of the mine and surrounding district were enhanced by applying digital terrain corrections. The corrected Bouguer anomaly revealed a hitherto unknown positive anomaly associated with the ore zones of the Renison mine. The gravity anomaly of the model was also computed. Unfortunately, the limited resolution of the observed data prevented the delineation of ore targets. The terrain-corrected Bouguer gravity data were also used to model the shape of the underlying non-magnetic Pine Hill Granite. A computer inversion method was implemented to build a 3D block model of the granite. Results agreed with previous conventional 3D modelling techniques but yielded improved resolution of the granite form. The project involved development of new computer software to build and edit the large and complex 3D geophysical model of the mine and to compute the model's magnetic and gravity responses. Software was also developed to build and compute the gravity response of a 3D block model of the underlying granite.

Jan 1, 1997

Open stoping dimensions are typically controlled by a number of factors including production drilling capacity, scheduling, fill constraints, orebody dimensions and host wall rock conditions. Frequently host wall rock conditions are the key control on stope dimensions. As a new mine is brought into production, there is a steep geotechnical learning curve for those associated with the development of the mine. Initially, the experience and observations gained at other mines is used to guide the stope design. As experience is gained at the new operation, site specific techniques can be validated for use. This has been the case at BHP Cannington, where a heavy emphasis has been placed on the validation of empirical stope stability techniques for site specific conditions and experience. A range of empirical and numerical techniques can be applied during the design of open stopes. The empirical techniques are an experience based application of known performance levels during the design of open stopes. The numerical modelling and structural tools can be used to compliment the empirical techniques so that an understanding can be gained of the likely stress and structurally controlled failure mechanisms.

Jan 1, 2000

Some mqre facts and inferences are presented in amplification of a recent paper on the geology of the Kalgoorlie Golden Mile stressing the volcanic origin of its rich gold ores, some of which are considered tobe exhalites. Previously unpublished and largely unmapped pyroclastic features in carbonated and chloritized, but not in amphibolitic, country rock are brought to attention. This applies particularly to the main host, viz. the relatively coarse-grained quartz dolerite greenstone (Q. D. G.), i.e. Golden Mile Dolerite, and gives more credibility to the spatial association of the rich Green Leader and telluride ores with bodies of sediments and tuffites occurring within, or adjacent to, Q. D. G. There may be an intrusive relationship with contiguous mafic amphibolites of doleritic origin, but this is not certain and can only be resolved by morecomprehensive mapping than in the past. Volcanic features have always been recognized in CalC Schist, i.e. Paringa Basalt, more so recently in the shape of coarse volcanic breccia.Iu the subsequent deformation of the gold ores since their inital emplacement there appears to be a structural parallel with some Canadian base-metal deposits, most of them of volcanogenic origin.

Jan 1, 1976

By Rosenblatt M, Gilroy J. A C Cunningham C V B

Vaal Reefs Exploration and Mining Company Limited operates one of the largest producing gold mines in the world. The annual production of 76 tons of gold from 12 million tons of ore treated is obtained mainly from underground sources. Daily some 6.6 km of stope face is blasted and 41 tons of explosives is used to break the rock. The mine employs 45 000 men of whom 35 000 work underground. The company operates nine large vertical shaft systems of which seven extend more than 2000 m below surface and an eighth, currently being sunk, will bottom at 3700 m below surface.

Jan 1, 1995

By Ibaragi K

High grade ores were intersected in 1981 by a scout drill carried out by the Metal Mining Agency of Japan during a reconnaissance dril ling programme. The original aim of the hole was to explore a deep target where geophysical anczralies overlapped the abandoned old drifts (gravity- high, resistivity-low by airborne EM, and resistivity-low near the surface and high at depth by Schlumberger deep sounding). Subsequently, a follow-up drilling programm was commenced by the Sumitcrro Metal Mining Co Ltd, and all the 18 holes intersected high grade ores. The resources were then "guestimated" to contain ca.120 tonnes gold with an average grade of 80g/t Au between -40m and +120n a.s.l. The underground development was started in December 1982 and the first crosscut intersected the ore body at 100m level (a.s.l.) in July 1985.

Jan 1, 1987

The lignite mines in the Latrobe Valley of Victoria/Australia have been using continuously operating mining systems for more than 50 years. The relatively small bucket chain dredgers of the early years have been progressively displaced by bucket wheel dredgers with increasing size, increasing capacity and increasing service weight. The large machines for the new open pit Loy Yang have a bucket wheel outreach of 46m, an effective capacity of 3350 bm' coal/h respective 2500 bm' overburden/h and a serv- ice weight of approx. 4500 t. The time between signing of con- tract and starting of operation for these machines is at least four years. The high service weight, the resulting high capital invest- ment and the long period for design, design review, manufac- turing, erection and commissioning of these machines directed the SECV to investigate a possible application of compact dredgers for the Latrobe Valley.

Jan 1, 1989

By A Torpy, N C. Wilson

Improvements in electron optics, field emission gun design, and X-ray detector technology have led to the development of a new class of microanalysis tools. By combining multiple wavelength dispersive (WD) spectrometers, spectral energy dispersive (ED) spectrometers and cathodoluminescence (CL) data sets, a wealth of information can be collected during routine electron beam mapping and analysis. In this paper, data collection on a field emission electron microprobe equipped with five wavelength dispersive, two silicon drift energy dispersive X-ray spectrometers and a wavelength dispersive linear array optical spectrometer has been automated with the optical, electron and X-ray signals being collected in parallel. To analyse the large hyperspectral data sets we have implemented an autoclustering strategy that can be used to produce a quantitative chemical phase map. The cathodoluminescence spectra can be deconvoluted to produce peak intensity maps, which are then converted into elemental speciation images with quantitative sensitivity down to parts per million levels. Both methods are illustrated using typical mineral processing examples, firstly a Ni-laterite sample is investigated with the fine-scale distribution of Ni examined in detail. Secondly, a scheelite sample with rare earth zoning in mapped and rare earth levels quantified.

Jan 1, 2008

By Sparrow GJ, Woodcock JT

A sample of pyrrhotite flotation concentrate pulp assaying 15.3 g/t An, which had been prepared from an old tailing dump, was treated to extract the gold. Examination of the concentrate with an SEM showed that exposed or free native gold, 5-40 ¦m in diameter, was present but no locked gold was observed. Direct cyanidation of the concentrate to extract the gold showed that the flotation reagents present inhibited gold extraction. A range of pre-treatments was used to overcome these effects.Direct cyanidation for 48 h extracted only 26% of the gold, indicating possible contamination of the gold in the concentrate with flotation reagents. Pre-treatment of the concentrate pulp by aeration for 24 h, or by 72 h aeration with an addition of 3.65 kg/t of sodium sulphite, gave little improvement in gold extraction by subsequent cyanidation. Pre-treatment by filtration, or by aeration with 12.5 L/t 100 volume hydrogen peroxide, followed by cyanidation for 48 h gave gold extractions in the range 67-77%. Combining filtration and an aeration period with hydrogen peroxide addition raised the subsequent cyanidation extraction of gold to 88%, giving a tailing assaying 1.5 g/t Au.

Jan 1, 1990

The origins of instrument application in the Mineral Industry are discussed. Development of measurement techniques pertinent to the industry is described as is the early application of mini-computers. The current application of microprocessor based equipment and the benefits obtained from this range of equipment are discussed. A speculative opinion as to what future instrument development may offer the industry is outlined.

Jan 1, 1985

By Carrucan M. J

Costain Resources Limited operates two open cut coal mines in the Hunter Valley coalfields of New South Wales, Ravensworth Mine and Warkworth Mine. The location of the Ravensworth operation is shown in Figure 1. In the case of the Ravensworth Mine, Costain Australia is essentially a contract miner and is contracted to supply coal to Pacific Power (previously The Electricity Commission of New South Wales), on contracts won through a tender system. Due to the existing infrastructure and the lease area that associated with the contract, the mining strips at Ravensworth South have a maximum strike length of 1500 metres. This paper deals with the methods of scheduling used to overcome the challenge of mining the short strike length, multi-seam deposit at Ravensworth South.

Jan 1, 1992

By C Philander

The West Coast of South Africa is well known for its placer gem quality diamond deposits and also associated with these hosts of Cenozoic unconsolidated marine and aeolian sand and gravel are significant concentrations of heavy minerals. Exploration for economic concentrations of zircon, ilmenite and rutile along the coast started in the mid-1980s. This resulted in the discovery of an inferred 1.6 billion tonne resource with a grade of ten per cent total heavy minerals (THM), which developed into the Namakwa Sands Mine, a world-class producer of heavy minerals. Several other resources, including satellite deposits proximal and distal to the mine area, extensive diamond mine dumps and present day beach placers, demonstrate the vast heavy mineral potential along the West Coast. The favourable gangue to economic mineral ratio, a higher zircon content compared to other similar deposits, relatively lower U+TH content of zircon, low slimes content and effectively pristine low chromium-manganese ilmenite of these deposits, render them attractive exploration targets. Negative factors that will affect conventional mineral beneficiation and liberation include secondary mineral coatings and the regional coastal development of several layers of superimposed duricrust. The economically attractive heavy mineral assemblage along the West Coast is the result of erosion of the proximal, gneissic Namaqualand Metamorphic Province and mature Table Mountain Group sandstone, concentration by marine and aeolian processes and preservation under arid climatological conditions over a period of more than 100 Ma.

Jan 1, 2008

By Bertrand D. L

Although investigations into treatment of Mt. Keast (a hill of tailing) began as early as 1940, it was not until the Imperial Smelting Furnace (I.S.F.) was installed at Cockle Creek by Sulphide Corporation that its treatment became eooncmically feasible. Early investigations and milling operations which began in mid-1976, with their developments are described. Metal recovery involves sulphide flotation, oxide flotation and gravity techniques.

Jan 1, 1983

By Tonks E. E

The earliest discovery and mining of coal in the northern area of the Greta Coal Measures at Anvil Creek in 1862 was by William Farthing, however, some official records attribute the discovery to Thomas Frost in 1864. Frost's discovery was examined by William Keen, government examiner of coalfields, and further prospecting was carried out. This was followed by the pioneering work of C S Wilkinson, government geologist in 1884. Subsequently in 1886 C S Wilkinson entrusted a detailed survey of the coalfield to the then geological surveyor, T W Edgeworth David.The outcrop of the Greta Coal Measures around the Lochinvar dome was mapped by Edgeworth David and as soon as he reported his discovery, the Department of Mines reserved in the interests of coal mining an area of 23700 acres, which extended between what became the South Greta and Abermain No I Collieries.

Jan 1, 1993

By A Fareth

Constructed between 1885 and 1891, the New Croton Aqueduct (NCA) in New York State is a 50 km long (31 mi) brick-lined tunnel conveying water from the Croton watershed north of New York City to distribution systems in the Bronx and Manhattan. Except at two siphons, the aqueduct operates as an open channel conduit from the New Croton Reservoir downstream 39 km (25 mi) to the Jerome Park Reservoir in the Bronx. The remaining 11 km (6 mi) is operated as a pressurised conduit and includes a major siphon, of circular cross-section, under the Harlem River. The aqueduct has a flow capacity of approximately 1100 million litres of water per day (13 m3/s or 290 million gallons per day) and supplies on average ten per cent of New York CityÆs drinking water. The CityÆs water supply system is operated and maintained by the New York City Department of Environmental Protection (NYCDEP). This paper covers the work done during the three main stages of the program to rehabilitate the entire NCA: inspections, design and rehabilitation. It also includes some of the more interesting structural findings of the original construction as well as documents and drawings from the NYCDEP archives. The rehabilitation program has been underway in phases since 1993, with inspections scheduled to minimise outages, allowing this strategic aqueduct to remain in service during critical seasonal periods. The open channel flow section of the aqueduct in the north is horseshoe shaped, with inside dimensions of 4.1 m (13.6 ft) in width and 4 m (13.5 ft) in height. The pressurised section is 3.7 m (12.3 ft) in diameter, and includes a 90 m (330 ft) deep siphon under the Harlem River. A total of 163 million bricks were used in the construction, enough to build a 48 km (30 mi) wall around Manhattan Island, 3 m (10 ft) thick and 15 m (50 ft) high.Between 1993 and 1997 a series of in-tunnel investigations were performed in the open channel portion of the NCA, consisting of field inspection, non-destructive geophysical testing, and coring of the brick liner. Between November 2004 and September 2005, a major inspection program was conducted to assess the condition of the 11 km (6 mi) long pressurised section and all shafts, headhouses and blow-off structures along the entire 50 km (31 mi) alignment. Inspection methods included using an underwater remote operated vehicle (ROV) equipped with sonar and cameras to inspect the deep siphon, fibre optics examinations of probe holes drilled through and beyond the brick lining, and core holes and geophysical inspections to assess properties of the liner and behind-the-liner materials. A water pressure and test grouting program was conducted to assess methods and expected grout takes for the rehabilitation work in the pressurised sections. The rehabilitation program is anticipated to be completed in 2010.

Jan 1, 2008

By S KandT

The FalTmT iron ore deposits are located in the so-called æBirrimianÆ volcano-sedimentary complex that extends in a general NE-SW direction across eastern Senegal and part of Mali and Guinea. The rocks underwent folding and greenschist facies metamorphism, as well as various events of granitoid emplacement. The deposits form part of the DialT-DalTma Series of the Birrimian Supergroup and were subjected to contact metamorphism. The Fe-mineralisation occurs as primary magnetite within the metamorphic aureole. Supergene oxidation (martitisation) of this mineralisation produced the hematite-rich iron deposits that can be seen as prominent hills across the plains of this south-eastern corner of Senegal. BRGM of France and Miferso (SociTtT des Mines de Fer du STnTgal-Oriental) have conducted several phases of prospecting since 1957. Their aim was to delineate the hematite deposits and to assess the grade, beneficiation characteristics and marketability of the iron ore. A feasibility study by Fluor Daniel was completed in 1992. Results indicated that, at the time, the resource could not compete in the international arena in terms of size and accessibility. The growing iron ore market and additional available resources in the area now challenge the 1992 feasibility study results and put the old kid back on the iron ore block. The project faces some mining challenges, such as the amount of magnetite in the hematite product that will be acceptable to the market. Previous project evaluations only considered the secondary hematite deposits as economically viable. It is therefore important to accurately delineate the magnetite/hematite contact zone to optimise the resource tonnage. Project logistic constraints also exist in terms of railway access and harbour facilities. The resource is, however, well situated for the European iron ore market and aims to find a place in the rapidly expanding iron ore seaborne trade.

Jan 1, 2005