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Lithocaps are potentially voluminous zones of advanced argillic and associated argillic alteration located above the subvolcanic intrusive environment. They constitute exploration objectives for epithermal and porphyry-type deposits. High-sulphidation epithermal deposits may be sought within lithocaps, whereas low-sulphidation deposits may exist on their edges. Porphyry Cu-Au/Au deposits may be accessible beneath lithocaps if systems are telescoped sufficiently. Oxidation of the basal, pyritic parts of lithocaps may promote supergene sulphide enrichment under appropriate tectonic and climatic conditions.

Jan 1, 1995

The Tom's Gully gold mine is located 90km ESE from Darwin, in the Northern Territory of Australia. The orebody is the auriferous portion of a large sulphide rich quartz reef, hosted in the Wildman Siltstone Formation of the Early Proterozoic Pine Creek Inlier, at the NH extremity of the Mount Bundey granite-syenite intrusion. It was discovered by Carpentaria Exploration Company Pty Ltd on November 17th, 1986, using stream sediment geochemistry.The reef is 800m long at surface, strikes E-H and dips approximately 300 to the south, becoming progressively less steep. Only the eastern half of the reef is auriferous, with gold grades averaging 9 g/t plus anomalous silver, base metals and arsenic.The enclosing siltstone is a dark grey banded carbonaceous and pyritic metapelite, showing areenschist regional metamorphism and thermal effects from the adjacent pluton. Local folding plunging gently SW is cut by a south dipping fault, probably a thrust, in which the reef was later formed at about the time of the granitic intrusion. The main sulphides in the reef are pyrite and arsenopyrite, with gold occurring as microscopic particles in...

Jan 1, 1990

By Butler I. K, Nicholson P. M

There are four main types of base metal and gold mineralisation recognised in the central Pine Creek Geosyncline. These are stratiform, polymetallic veins, stockwork/concordant gold-quartz veins and unconformity related uranium-gold-platinoid mineralisation. The stratigraphy of the central Palaeoproterozoic Pine Creek Geosyncline has been simplified into three groups comprising the Batchelor, Frances Creek and Finniss River Groups in ascending order. Stratiform mineralisation occurs within the Frances Creek Group. The earliest mineralisation is found adjacent to circular faults ringing basement highs. Higher in the stratigraphy, stratiform mineralisation is often associated with zones of high compression in the vicinity of basement highs. A synsedimentary-diagenetic origin for stratiform mineralisation is proposed. Polymetallic vein mineralisation occurs within the Frances Creek and Finniss River Groups. Its composition changes systematically through the stratigraphy similar to the stratiform mineralisation. The mineralisation is structurally controlled and usually occurs in the vicinity of basement highs. Stockwork-concordant gold-quartz vein mineralisation is hosted by the upper Frances Creek and Finniss River Groups. It occurs within compressional zones and along the Pine Creek Structure corridor around, above and particularly between basement highs. Mineable reserves occur in thick continuous semi concordant quartz-sulphide veins and/or stockworks. Unconformity related uranium-gold-platinoid mineralisation shows a close spatial relationship with the Palaeoproterozoic/Mesoproterozoic unconformity. The mineralisation is localised by structures formed during Mesoproterozoic deposition and is commonly adjacent to Archaean basement or its remobilised equivalents. The type of mineralisation (stratifom/polymetallic vein) is a reflection of local stress regimes, structure and physio-chemical conditions. An initial phase of stratiform mineralisation is postulated to have occurred with the first significant marine transgression in a tensional regime. A second phase occurred later during a compressive regime. "Ihermochemical sulphate reduction of mineralising fluids by hydrocarbons is invoked as the precipitation mechanism for the polymetallic vein type of mineralisation. Hydrocarbon generation is postulated to have occurred within the Frances Creek Group, in many places contemporaneously with the movement of mineralising fluids and basin compression. Polymetallic veins formed from the interaction of mineralising fluids and hydrocarbons which were trapped in suitable structures. An abundant, continuing supply of hydrocarbons was necessary to form significant deposits. Where these conditions were not net, the mineralising fluids largely continued their ascent to the near surface environment to form stratiform deposits. The stockwork/concordant gold-quartz vein mineralisation is a later event and occurred during the relaxation of compressional defonnation after deposition of the 1-inniss River Group.

Jan 1, 1994

A model has been developed for the per iodical maintenance of bins used for hydraulic hoisting in mining of steeply inclining coal seams. This model gives a control plan for hoisting, bin switching and bin maintenance on a regular schedule.

Jan 1, 1977

By Nixon C. A

The exploration of Mount Isa Mines' new copper source will require the development of a five kilometre 4.7 x 5.5 metre blind decline commencing 1000m below the surface and extending to 1600m below the surface. With virgin rock temperatures approaching 60¦C, the ventilation strategy represents a complete departure from any previously used at this mine, in that refrigeration becomes essential. The use of direct water to air cooling techniques has become commonplace in mines throughout the world and their application is being adopted at Mount Isa Mines. A heat load simulation routine has been implemented to allow for the design of refrigeration requirements, as well as to aid in the selection of diesel or electric equipment. This enabled planners to determine the size of a surface based refrigeration plant. Future refrigeration demand for expansion into the ore production stage has also been investigated.

Jan 1, 1988

By J D. Bryant

The Ernest Henry Copper-Gold mine, the third largest copper deposit in Australia, is located 35 km NE of Cloncurry in the Mt Isa-Cloncurry mineral district of NW Queensland. Ernest Henry Mining Pty Ltd (EHM), a wholly owned subsidiary of Xstrata Copper Australia, operates the mine. Approximately 10.2 Mt of ore grading 1.12 per cent Cu and 0.56 g/t Au were processed during the 2001 - 2002 financial year. The Ernest Henry plant produces copper-gold concentrate, which is trucked to Mt Isa for smelting. The Ernest Henry deposit is a member of the diverse Fe-oxide-(Cu-Au) class of deposits. The orebody is hosted within a sequence of moderately SSE-dipping, intensely altered Paleoproterozoic intermediate metavolcanic and metasedimentary rocks. Copper (chalcopyrite)-gold mineralisation occurs mainly within the magnetite-biotite-calcite ¦ pyrite matrix of a 250 m + 300 m pipe-like breccia body. The breccia pipe comprises two anastomosing lenses separated by a lower grade, clast-supported breccia zone. Several anastomosing brittle faults affect the macro-geometry of the orebody. Copper grade is proportional to the degree of matrix support in the breccia. The July 2002 Ore Reserve was 88.7 Mt @ 1.0 per cent Cu and 0.5 g/t Au. Resource estimation at Ernest Henry is based on a large database of predominantly diamond drill hole information. Drill spacing is typically 50 m + 50 m. Ordinary kriging is used to estimate Cu, Au, SG and IST (oxidation indicator) into model parent cells of dimension 20 m E + 20 m N + 16 m RL. The block model is comprised of five geological-geochemical domains represented by 3D wireframe surfaces. Zonal control, where samples and blocks are assigned the same domain number, is used to control grade estimation. The geometry of the domains defines hard grade boundaries across strike and soft boundaries along strike A Deep Drilling Project was initiated in August 2002 with the initial aim of testing the down-plunge extension of the orebody to a vertical depth of over 1 km. The encouraging intersections to date have resulted in a significant increase in the mineÆs open pit Mineral Resource together with the identification of an underground Mineral Resource. Added benefits of the project included an expanded and updated geological legend and an improved understanding of the host geological sequence.

Jan 1, 2003

The flotation circuit handling Peko ore at Peko Mines N.L. was examined in July 1970 with a view to determining simple changes in circuitry or reagents which could improve the grade and recovery of the final copper concentrates. The investigation included sampling over one shift followed by detailed testing of the samples by sizing-assays, sizing-mineralogy and sizing-liberation. Mass balances were carried out over total streams, the component minerals and the copper contents. Some laboratory work was carried out to assess the effect of salinity on flotation. In order to handle the sizing-mineralogy calculations a computer programme was set up. The raw data were corrected for locking factors, then mineral and elemental distributions cal- culated for each screen fraction and the total sample. Calculated assays from grain counting were compared with chemical assays. Recoveries through the size-ranges re- vealed very rapid flotation of copper minerals at sizes below 350 mesh. This pointed to a possible circuit improvement by desliming rougher tailings ahead of the scavenger stage. A strong correlation was found between water in concentrates and gangue recovery for the subsieve sizes. This pointed to clean water additions to the cleaner circuit as a way to 1 Project Consultant, The Australian Mineral Development Laboratories, Adelaide, South Australia.

Jan 1, 1972

By Heesteman LJL, Turvey DJ

The Mangani mine in West Sumatra is historically one of the most important precious metal mines in Indonesia, although the past production by World standards is small, totall- ing 5.66 tonnes gold and 242 tonnes silver. The geology is dominated by a distinctive NW-SE graben structure formed by dextral splay faults from the Sumatran Fault System. Quartz- rhodochrosite-rhodonite-Ag-Au veins are hosted by Tertiary pyroxene andesite volcanics and quartz-phyllite conglomerates, on N-S tensional fractures which intersect the Mangani graben. Intrusive rocks include andesitic dykes, pyroxene microdiorite, and hornblende granodiorite. Quartz-epidote-pyrrhotite alteration is related to concealed intrusions. Precious metal vein mineralization is characterized by: high Ag/Au ratio (>25); complex sulphide mineralogy of Fe, Mn, Ag, Cu, Pb, Zn, As, Se and the occurrence of Sn as stannite; low total sulphide content (

Jan 1, 1987

By Williams ID

Ore and coke of various size fractions (1 to 11 mm) were packed in a column (146 ó) and resistance to air flow measured under a range of conditions. Results have shown that layered charging results in an interface having essentially a directional structure the thickness of which is directly proportional to the coke and ore size ratio and whose flow resistance exceeds that of the coke layer many times its thickness. Friction factor - Reynolds number plots showed large positive departure from the Ergun equation for all components investigated whilst functional analysis and that in terms of bed constants, showed a strong dependency of the pressure gradient on bed properties and the actual particle size as well as the size ratio. It is also shown that pressure gradient in mixed beds follows previously reported behaviour and that a directional interface offers higher resistance to flow than a mixed interface having the same volumetric ore/coke ratio. Significance of results to practice is discussed.

Jan 1, 1975

By Houtgraaf M

The Far Fanning gold deposit is situated 60 kilometres south-west of Townsville (Fig. 1). Previous recorded production is 3756 tonnes returning about 1600 ounces of gold. This has been taken from surface and shallow underground workings- scattered over the strike length of the deposit of 1700 metres. The main production period was from 1895 to 1908.Previous exploration involving extensive trenching and sampling has been: carried out intermittently. since the 1930's, by Gold Mines of Australia (1932), Placer (1974), Anaconda (1975), Marathon (1980-8-1), Aberfoyle (1981-82), and The Northern Queensland Company (NQC) (1983-present).In 1980 Marathon undertook an extensive drilling programme to test the oxidised mineralisation. Over 200 percussion holes and- 7 diamond holes were drilled along traverse lines spaced 29 to 103 metres apart covering a strike length of around 1800 metres.

Jan 1, 1986

When Matthew Flinders entered in his log `This land forms the South side of the large bight; and besides projecting beyond the coast line, and being a little higher than usual is remarkable for having some reddish cliffs in it, and deep water near the shore', he was commenting on the deposit of bauxite at a place now known as Weipa. This sighting took place on 9 November 1802, and probably represents the first direct entry in Australia acknowledging a potential mineral deposit. Flinders, of course, had no idea as to what he was looking at, nor did he land to determine its content. If he had, he probably would have had no idea of the substance, and even less knowledge of its use. Nothing further was done to this for about 150 years.

Jan 1, 1993

The Nagambie heap leach gold mine commenced production of gold in September, 1989. The mine,120km north of Melbourne in Victoria, Australia, was developed by Perseverance Mining Cor- poration Ltd, a junior Australian mining company, with no other operating mines. Gold production to December 31, 1990 was 47,621 oz. The mine is now producing at the rate of about 45,000 oz per year. As of February 28, 1991, resources at the mine are 5.1 million tonnes measured, at 0.65g/t Au while reserves were 1.65 million tonnes at 0.86g/t Au of proven, heap leach ore, plus 0.37 million tonnes at 0.40g/t Au, of dump leach ore. Metallurgical recoveries expected are 80 per cent for the heap ore and 60 per cent for the dump ore. Perseverance Mining Corporation was listed on the Australian Stock Exchange on April 2, 1987, after a capital raising in March that year. At this time the company's issued capital was 4 million ordinary 25ó shares, 3 million of which were issued to the public to raise $0.75 million.

Jan 1, 1991

The Australian mining industry has suffered from a decline in its public image during the past decade. This has occurred partly as a result of increased questioning of accepted social and economic values since the mid-1960s and the greater restrictions placed on industry since then, and partly ò from the industry's inability to effectively answer its critics. Public opinion surveys have shown the depth of the decline in the industry's community acceptability and highlighted those issues which people regard as disadvantages of mining. The industry's poor public image has contributed to the difficulties of attracting young people to take up professional careers in mining. All those involved in the industry have a responsibility to assist in activities designed to improve the industry community Acceptability.

Jan 1, 1981

By S Wainio, P J. Beckett, T Miller

Lichens are a symbiosis of fungi and algae. Air borne elements and gases are absorbed very efficiently over the entire surface of the lichen, because they have no protective structures such as a waxy cuticle or stomata. A survey in 1977 (one year before the Sudbury Regreening program began), indicated that several Cladonia spp had invaded the soil in Sudbury’s open birch woodlands. Pollution sensitive species such as Cladonia rangiferina and C. mitis occurred 20–25 km from the smelters. It was anticipated that the improvements in air quality and reclamation efforts would allow a natural invasion of pollution sensitive species into what once was a lichen desert that surrounded the smelters. The purpose of this project was to study the invasion of terricolous (soil-inhabiting) communities of lichens and mosses on reclaimed land in the Sudbury region 45 years after commencement of the Sudbury Regreening Program.

Aug 2, 2023

Cretaceous volcanic activity (Hauterivian Albian) in the Peruvian Andes can be found along the coast of Peru and the western edge of the Andes mountains between 15o30'S and 5o30'S, extending discontinuously in south to Chile and north to Ecuador and Colombia. This volcanic activity formed in three aborted marginal basins; the NNW-trending volcanic Ca±ete and Huarmey, and NNE-trending Lancones basins. These volcanic rocks are predominantly andesitic and basaltic in composition, of calc-alkaline and tholeiite affinity with subordinate dacitic and rhyolitic rocks. One notable feature is the appearance of æocoitasÆ from Ica (14oS) south to Santiago de Chile. These rocks have a calc-alkaline to alkaline affinity. From south to north, the continental crust gradually becomes thinner, allowing mantle material to rise towards the surface. Ophiolitic sequences of this type form a marginal basin in Colombia. Very low-grade regional metamorphism which affects the volcanic rocks also varies gradually from south to north. Between Santiago de Chile and Ica this takes the form of burial metamorphism, with moderate geothermal gradients (20o-30oC/km). Metamorphism in the Huarmey basin is transitional between burial and ocean-floor metamorphism, with very high geothermal gradients (>3000C/km). High geothermal gradients are also apparent in metamorphism of the Lancones basin, though less than the other basins. Ocean-floor metamorphism is present in the ophiolitic sequence in Colombia. Associated mineral deposits in the Huarmey and Lancones basins, and in the north, are of the volcanic massive sulphide-type (VMS). The principal deposits in Peru are Leonila Graciela (20 Mt Zn and Pb) and Tambogrande (40 Mt Cu and Zn). There are also smaller mines and prospects. To the south of Lima, manto-type Cu deposits (CuMT) are found with a mineralogy of chalcopyrites, pyrites, magnetite, actinolite and apatite. The main example is Raul Condestable (10 Mt Cu). Other prospects are present to the south and Chile has some very large mines of this type (El Soldado, Lo Aguirre). The notable differences between the CuMT and the VSM deposits are thought to be the result of the prevailing conditions in the earthÆs crust during the Hauterivian Albian. To the south, calc-alkaline and alkaline volcanic activity in aborted marginal basins, with thicker crust, was thick, produced moderate geothermal gradients associated with burial-type regional metamorphism and deposits of CuMT. In the north aborted marginal basins associated with calc-alkaline to tholeiitic volcanic activity and a gradually thinning crust, produced transitional regional metamorphism between burial-type and ocean-floor type, associated with high to very high geothermal gradients and VMS deposits. In Colombia these conditions led to ophiolite extrusive rocks, ocean-floor metamorphism and also VMS deposits.

Jan 1, 1999

By Nichol R

- PART A The Hoppers Crossing Pumping Station is one of the principal components of the Western Trunk Sewer Project which replaces the 90 year old Main Outfall Sewer and will convey 60% of Melbourne's sewage flow from Brooklyn to the Board's Farm at

Jan 1, 1987

Laboratory experiments have been used tostudy a wide range of convective processes which are significant for the formation of rocks and the ores that form in them. Metal-rich solutions flowing through the sea floor produce 'black smoker' chimneys; both the size and structure of a solid chimney and the height to which the plume of effluent rises above it can be predicted using model experiments. Analogues of processes in solidifying magmas can also be studied using crystallizing aqueous solutions. The release of lighter or denser residual fluid as crystallization proceeds, and the resulting compositional convection, have a vital influence on the differentiation of initially homogeneous magma and on the evolution of stratified magma chambers. Mixing during the replenishment of magma chambers, and its dependence on the rate of filling and on the fluid properties, have also been studied on the laboratory scale. Experiments carried out in different geometries have been applied here to the formation of platinum and chromite ores and komatiite lavas. Larger-scale mantle convection, in particular the motion of subducting plates and plumes rising from the core-mantle boundary, also determine the tectonic settings in which ore bodies form. These phenomena too can be usefully investigated in laboratory experiments using very viscous fluids.

Jan 1, 1990

For the mineral industry, sustainability seems to mean socially positive and ecologically neutral mineral extraction. Mines are financed and developed in response to demand for their products. The purpose of my paper is to indicate the potential dimension of demand. As part of an unrelated study which I undertook ten years ago, it became apparent that there is a persistent relationship within communities between infant mortality and mineral use; greater mineral use corresponds to a lower rate of infant mortality. This comes as no surprise; sufficient potable water, a reliable supply of food, hygienic waste disposal, hot water and refrigeration all improve the chances of survival of the more vulnerable members of any community. The predictable provision of these facilities requires the application of minerals. This relationship is supported by a table (Appendix 1) included in the UNICEF publication, æThe State of the WorldÆs Children 2001Æ. This table lists regional infant mortality rate (IMR) statistics from around the world, including a listing for æindustrialised countriesÆ. Such countries experience an IMR lower by an order of magnitude than any other region. æIndustrialisedÆ inevitably involves the use of metallic and energy minerals. The principal use of copper is in the generation and distribution of power; it is fundamental to any industrialisation. IMR is a valuable connection because it quantifies caring for the young, a vital strategic driver of human behaviour independent of time, place, fashion or economic circumstances. I have tabulated the population, IMR and the copper demand per head of population for countries containing over 99 per cent of the population of the world in the years 1950, 1960, 1970, 1980, 1989, and 1999. These countries have been consolidated into four groups, Very High, High, Medium and Low rates of infant mortality (UNICEF has used this terminology; the Low group includes all the æindustrialised countriesÆ). The purpose of this consolidation was to reduce the volume of work, to dampen out the impact of regional wars and business cycles, and to dampen out the variable quality of information. Based on the pattern of the copper demand, population and IMR over the last 50 years, I have projected the likely copper demand in 50 years time. A dominant feature of my tabulation is the increase per decade in copper use per head and a corresponding reduction of the IMR. The word æuseÆ is preferred to æconsumptionÆ because it is estimated that over 80 per cent of all the copper ever mined is still in circulation There are two major influences at work; one is the absolute increase in population (UN estimates for 2050 are updated periodically) and the second is the movement of countries into a higher pattern of use and lower IMR. For example the Medium group in 1989 had an infant mortality rate approximating that of the Low group in 1960. With the population of the Medium group (which includes Russia and China) forecast to reach 2.6 billion in 2050, the world copper demand in that year will be significantly greater than the present figure. Nevertheless it will not be as great relatively as the increase of over 300 per cent in the last 50 years.

Jan 1, 2002

By Shklyar FP, Babushkin NM, Bokovikov BA, Fedotov PB

A mathematical model for gas flow dynamics and heat and mass transfer processes occuring in the tuyere raceways and in the zone of the final for- mation and heating of pig iron and slag has been developed and simulated on a digital computer. It takes into account the formation and size of the raceway zones, combustion of coke and its substit- utes, oxidation of the metal, radiation from the gases to the raceway boundaries, physical heat losses and the direct reduction of the pig iron elements below the raceway zones. To evaluate the distribution of heat produced by the oxidation of metal between gases and prod- ucts of smelting, the problem of heating the mat- erials in the raceways with the sources of heat in the materials under conditions of intensive gas circulation in the raceways is solved. To determine the amount of heat transferred by radiation from the gas to the boundaries of the raceways, the problem of radiant heat transfer be- tween two grey bodies forming a closed system is solved. Using the structural parameters of the furn- ace, the inlet parameters of the combination blast and exit parameters of the melt, the model permits the calculation of the temperatures of materials entering and leaving the raceways and also the res- idual temperature of the gases, which qualitatively differs from the theoretical combustion temperature. Analysis of the operation of several different blast furnaces has shown that the overall picture of the interaction between gas flow dynamics, mass and heat transfer processes occuring in the race- ways and in the zone of final product formation, obtained with the aid of the model, now permits us to approach from a different position the deter- mination of the limiting factors in furnace operat- ion. It also allows us to explain certain phenom- ena observed in blast furnace practice and to dis- cover new relationships which may be used in analy- sis and control of the smelting process.

Jan 1, 1981

INDEX OF CONTENTSIntroduction.Systems of classification of coals.RankClassification of Australian coals.Defects of systems in use in other countries.Indexing by Fuel Ratio.Classification by Ultimate Carbon/Ultimate Hydrogen.Relationship between Fuel Ratio and ultimate composition.Suggested convention for classification.Origin and Evolution.Notes on directions of change of composition on Carbon Hydrogen chart.Summary and conclusion.Acknowledgments.Bibliography.Appendix.

Jan 1, 1948