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Reconnaissance geochemical exploration in the vicinity of low angle detachment faults which bound the core of the Paparoa metamorphic core complex yielded Au up to 14 ppm, with 35% of greywacke, granitoid and quartz vein samples in the northern range exceeding the 0.01 ppm detection limit. Au is associated with Ag, As, Sb and Cu anomalies consistent with epithermal-type mineralisation. The Ag and Cu anomalies also distinguish this mineralisation from older, mesothermal Au deposits widespread in the Ordovician 'slate belt' greywackes, which comprise much of the upper plate of the core complex. Baryte, molybdenite, fluorite and stratiform U mineralisation in the northernPaparoa Range may also be related to hydrothermal activity along the detachment fault zones.

Jan 1, 1995

When the first rush of miners took place on the Molyneux River, in the Dunstan Gorge, the gold was won by means of cradling the gravel, which was shovelled from the various beaches and crevices in the rock-bound sides of the river.The above method of winning the gold was only practicable when the beaches were not covered with water, hence the work was usually carried on during the winter months, the ordinary level of the river during spring and summer months being some ten or twelve feet above winter level. The melting of the spow in the Lakes water-shed being responsible for the high summer level of the river.As the available beaches were worked out, other methods of winning the gold were proposed and worked with more or less successful results the first advance being to work the bed of the river by means of a spoon dredge. The spoon was made with a round lip or ring of iron, having a steel cutting edge on one half of the circumference, at the opposite side a socket being forged to take a long spar or boom, which was securely fitted thereto. At intervals round the hoop, half-inch holes were bored to enable. a bullock-hide bag to be laced on to same. The spoon was worked from a pontoon which carried a crab winch, tackles and the necessary washing appliances to treat the washdirt lifted. In starting to dredge, a tackle was attached to near the upper end of the boom, and a line or chain was carried over a cat head from the crab winch...

Jan 1, 1901

In a previous paper the writer dealt -with the jasper bar formations and their relationship to the structural geology of older pre-Cambrian rocks in the goldfields districts of Western Australia (24). He has pointed out in this ahd other papers that jasper bars, or banded iron formations, banded hematite or ,magnetite quartzites, jaspilites and related banded ferruginous or non-ferruginous cherts, occur in abundan'ce in the Older Greenstone Series of Western Australia (22), (24), (26). They are considered to represent special forms of banded ferruginous sediments, and are usually fpund in the field interbedded with more or less metamorphosed pasaltic 01' andesitic lavas and tuffs, now amphibolites, together with occasional thin bands of normal pelitic sediments, which go to make up a large proportion of the Older Greenstones in thfs State (26).Great thicknesses of fiat-bedded ]:landed ferruginous cherts are also found associated with cherty' carbonate rocks; quartzites, shales and thin-bedded dolomite whicIi constit'ute the Nullagine (Pl'oterozoic) system in the northwest of Western Australia. In the Hamersley Range district these banded ferruginous chert beds are the hosts of important deposits of blue amphibole asbestos.In the paper mentioned above brief reference was> made to the importance, of geological structure in relation to economic geology, particularly in the goldfields regions of Western Australia, and it was shown that jasper bars may have an important role in the study of 'the structural geology of many of these regions. Of possibly more immediate economic importance is the part that these rocks play, both directly and indirectly, as host rocks for mineral deposits-the chief of Which are gold, iron ores, blue asbestos, and manganese ores. The blue asbestos bearing banded iron formations mentioned above are confined to the younger pre-Cambrian Nullagine formations. They have been described in detail elsewhere (23). In this paper it is proposed to discuss the economic geology of the jasper bars found in the older pre-Cambrian series.The jasper 'bars have in themselves little or no intrinsic value except perhaps some of the more highly coloured and banded varieties which may be utilised for ornamental and decorative purposes. Probably the best known of such varieties is the so-called "marble bar;" a belt of, strikingly coloured banded chert occurring just south and west of the famous town of that name (see Fig. 1t). This consists of a hard, very fine, even-grained rock with alternate individual stripes varying from the thickness of a sheet of paper up to an inch or more in width, and ranging in colour from clear white to yellow, from various shades of pink to brilliant...

Jan 1, 1943

By L Lachance, F Flament, D Leroux, S GariTpy

"Considerable metal values are often locked in stockpiles (ore, concentrates, heap leach pads, slags, reverts, etc.) and process equipment (bins, holding tanks, thickeners, etc.). This is more than enough to justify accurate accounting of such in-process metal inventories from both financial accounting and operational perspective. However, accurately determining the metal inventory of an in-process unit is often a challenge in industrial practice. Audits have shown that available indirect or direct measurements often carry large inaccuracies. Sooner or later, ignoring these measurement errors lead to unexpected incoherencies in reported metal balances. In such situations, coherent metal balances are then achieved through subjective and sometimes significant adjustments of in-process inventory levels. While such metal accounting methods applied by mineral processing engineers used to be rarely challenged, they are now being increasingly scrutinised by various stakeholders. Hence, metal accounting procedures that mitigate subjectivity in adjustments while still coping with the unavoidable uncertainty are more relevant than ever.This paper reviews three different metal accounting methods for reporting in-process metal inventory values. Their individual application strongly depends on the available measurements i.e. The indirect method where the metal inventory of a given process unit is determined by subtracting the cumulative reclaim from the cumulative feed carries important flaws. The direct method also comes with challenging accuracy issues so that emptying a process unit is often the best available inventory measurement. This reality is recognised for by further analysing a previously proposed operating mode where two interchangeable process units are alternately used. The third investigated method is the redundant method which combines indirect and direct methods for a given process unit. This paper reveals that the dual process unit operating mode and the redundant method can both significantly improve the estimation quality of in-process metal inventories.CITATION:Lachance, L, GariTpy, S, Leroux, D and Flament, F, 2013. Review of metal accounting methods for in-process metal inventories, in Proceedings MetPlant 2013, pp 102-117 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

Chalcopyrite concentrate was combusted in oxygen-nitrogen atmospheres, the composition of which ranged from 1-100 per cent oxygen. Factors studied included particle size, experimental temperature and oxygen concentration. The study was assisted by chemical and X-ray diffraction (XRD) analysis and temperature measurements of single particles. Size reduction occurring after melting was found to have a major effect on the overall reaction time. Thus time to attain ignition was largely determined by the original particle size, whereas combustion time was independent of this factor. For particles larger than 40 I'm in air the time to attain ignition predominated. The maximum temperatures measured for single particles were the result of pyrite present in the concentrate. Chalcopyrite did not attain thesame temperatures. Vaporization, either as CU(g) or CuO(g) lImited the temperature. Maximum temperatures measured for single particles of pyrite ranged from 1610°C in 14 per cent oxygen to 2360°C in 100 per cent oxygen (both at 700°C). Measured temperatures were compared with those calculated from a diffusion-based model.

Jan 1, 1983

THIS has been a much-neglected branch of engineering. With the majority of industries labour is the chief item of trouble and expense. Anything that will reduce trouble and increase efficiency is well worth considering. It is only of recent years that any attempt has been made on a scientific basis to improve conditions sporadic attempts having been made from time to time, privately and by law. Some have been successful, others unsuccessful not necessarily the fault of those who initiated the ideas, though naturally mistakes were made in some cases for want of experience, but those whom it was desired to benefit were not always prepared for the change, and by their distrust hampered schemes instead of assisting them.Man power is generally more expensive than machinery, though there are exceptions, such as when a small amount of work has to be done in a place where machinery does not exist, and it would not pay to instal any or where labour is cheap, and skilled workmen are scarce as in some tropical countries. When machinery is first introduced it generally causes the suspicion that it will deprive men of their work. It may cause men to vary the conditions of their work, and in some individual cases, when men are unable to conform to changed circumstances it may result in a certain amount of hardship; but, after all, the less competent must not hold back progress for the general good. Besides, changes as a rule do not take place suddenly, so old hands can generally find work at their particular calling 'till nature requires them to retire. In cases where men take to machinery, they not only find that they are relieved of the...

Jan 1, 1918

By M F. Jennings, N J. Corlis, B J. Thomas, L N. Tylkowski, A E. Petts, G D. McDonald

Flinders Mines is an iron ore explorer and developer with a tenement package located in the Hamersley Ranges region of Western Australia, approximately 70 km north of Tom Price. Exploration over the past five years has identified a Global Resource in excess of 900 Mt at a grade of 55.2 per cent Fe (+50 per cent Fe cut-off). This resource is spread across multiple deposits and has been divided into a number of mineralisation type domains. These domains are comprised of transported hematite rich detrital iron deposits (DID) and goethite dominant channel iron deposits (CID) as well as in situ bedded iron deposits (BID). The BID at PIOP is low in alumina and silica with a high calcined iron content making it an attractive exploration target. BID exploration techniques include a combination of mapping, structural analysis, downhole gamma logging and 3D geological modelling. Relationships identified between existing BID mineralisation, geology and structure has aided in targeting additional mineralisation across the tenement and highlighted other previously untested areas that warrant further investigation.CITATION:Tylkowski, L N, Corlis, N J, McDonald, G D, Petts, A E, Jennings, M F and Thomas, B J, 2013. The hunt for hydrous bedded iron deposits - an investigation into Flinders MinesÆ Blacksmith Tenement, in Proceedings Iron Ore 2013 , pp 121-126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Various steps, and complete sequences, for the recovery of lead and zinc from a mixed sulphide concentrate, high in silica and pyrite, have been tested.Oxidation steps of roasting in air or in a sulphating atmosphere and use of aqueous acidic, ammoniacal, and near neutral oxidation media were compared. Oxidation roasting or use of acidic media appeared most useful. Procedures for dissolution of zinc from calcines using sulphuric and sulphurous acid to avoid silica gelation problems are compared and a direct leaching procedure with sulphuric 'acid at controlled pH shown to be the most useful.Methods for the removal of germanium, nickel, and magnesium from zinc sulphate solutions prior to zinc electrodeposition were tested. The recoveries of zinc from ammoniacal solutions by electrolysis and distillation are compared.The dissolution of lead compounds from the residue of zinc extraction by amine and ammoniacal ammonium sulphate (AAS) solutions Was tested. Lead, sulphide was precipitated in filtera'ble form from AAS solutions. The reduction of lead sulphate to lead sulphide with sulphur was difficult, but possible. The various steps were used to deveiop five complete processing sequences, of which two were shown to be technically feasible and have potential economic viability.

Jan 1, 1975

With the proving of a mineable orebody at Orlando in May 1961, Peko Mines N.L. was faced with the decision of whether to mill the ore on site or to haul it 25 miles to central facilities at Peko. Orlando was a relatively small orebody, so that it was decided to haul, although no reliable assessment of possible ore haulage costs was available.The necessity for a good haul road was recognised from the beginning and a 17 mile, 12 ft wide, single seal bitumen road was constructed, to link the mine to the Stuart Highway and Peko. The initial selection of 20 ton capacity diesel-powered end-tipping ore carts was made, with the best information available at the time.Since then some 130,000 tons of ore have been carted over a period of 3 years, and this paper presents the experiences of this haulage operation and the lessons learned.A second mine has just been brought into operation at Ivanhoe, 19 miles from Peko. For this haul it was decided to use an ore haulage vehicle of the side tipping road train type, which would cart some 70 tons, or more than three times the load of the vehicles initially selected.Only about 5,000 tons had been hauled at the date of this paper, but preliminary figures indicate a cost 01 1· 65d./ton-mile as against 2·47d. for the smaller vehicles.It would appear that the road haulage of ore from small outlying mines to a central plant can be highly economical, if certain basic rules concerning haul roads and vehicle selection are followed. This paper does not try to determine the maximum tonnages and haul distances which would finally make road hauling uneconomical...

Jan 1, 1966

Iron ore in the Middleback Range area has a density and susceptibility contrast with adjacent rocks, and gravity and magnetic methods are applicable to exploration for it. The gravity method is satisfactory whether the ore mineral is hematite, magnetite, or limonite; the magnetic method is suitable for detecting ores which contain magnetite, such as some hematite ore, magnetite ore, and possible ore in the form of magnetite-bearing schists. jaspilites, and carbonate rocks.Geophysical exploration began in 1948 and is still in progress. The methods which have been used are aeromagnetic (83 per cent), ground magnetic (13 per cent), gravity (3 per cent), and others (1 per cent). Ground magnetic surveys have been made wherever aeromagnetic surveys recorded large anomalies. The gravity method is being used to investigate those parts of the area considered most favourable for ore occurrence.Qualitative and quantitative interpretation of the geophysical data has been made and the rocks causing selected anomalies tested by bores.Magnetite in the Middleback Group rocks produces the major magnetic anomalies in the area. The average magnetite content of magnetite-jaspilite, which is the commonest rock type, is 33 per cent by weight and that of magnetite-carbonate at the Iron Duke-Iron Duchess is 50 per cent. These rock types also contain hematite and the average total iron content of the former is 35 per cent and of the latter 50 per cent.INTRODUCTIONThe geology and iron ore resources of the Middleback Range area were described by Miles (1954). Since 1954, much drilling, mapping, and quarrying has been done but there is no published report of this work.The rocks which constitute the Middleback Range, Camel Hill-Cooyerdoo line, Katunga Hill-Iron Knob, and Ash Range (Fig. 1) belong to the Middleback Group of Middle Precambrian or late Archaean age. Most outcrops of the Group are jaspilites, formerly called banded hematite (or magnetite) quartzite. The high grade hematite deposits...

Jan 1, 1964

It has been fairly firmly established (Fisher, N. H., 1945) that the fineness of the gold in any ore deposit varies with the depth from the surface at which the deposit was formed, and, as a corollary to this, that it is dependent upon the temperature and pressure at the time of deposition. This relationship is such that, under certain conditions, the gold fineness, taken into consideration with other recognised criteria, furnishes a very sensitive and reliable guide to the relative temperature of ore formation, at least within the epithermal and the upper part of the mesothermal range.Definition of Fineness.The fineness of gold is calculated in parts per thousand and refers to the proportion of gold present in the naturally occurring metal in the lode, which is actually a gold-silver alloy, containing usually about 10 parts per thousand of base metal and up to 500 parts perthousand of silver. A clear distinction should be made between fineness and gold-silver ratio. The latter refers to the total gold and silver in the lode as determined by assay and is usually expressed as the ratio Au:Ag. Only in deposits where other silver-bearingminerals are entirely absent, which occurs comparatively rarely, can the gold-silver ratio be used as a measure of gold fineness and, in many cases, the two have no relationship. For instance, in the Edie Creek area in New Guinea, the lodes formed under shallow epithermal conditions all carry gold 500 to 550 fine, although the gold-silver ratio ranges from 1:100 to 1:1, in places in adjacent lodes.Determination of Gold Fineness.The fineness of lode gold can be determined only after it has been separated from all other minerals. Amalgamation recovers gold fairly cleanly - unless native silver is present - and the fineness of amalgam bullion is generally a reliable indication of the correct fineness of the gold. If the use of plates is involved, the bullion may be adulterated, but the effect of any copper, or other metal, that may have been introduced can be cancelled by assuming that the gold and silver shouJrl add up to about 990 fine, or by ignoring the base metal content altogether, which varies little in naturally-occurring gold, and in calculating for comparison purposes all fineness figures to the basis Au + Ag = 1,000.The composition of bullion obtained from cyanidation is generally intermediate between the true gold fineness and the total gold-silver proportion as determined by assay of mine or mill-head samples of Cyanide solution dissolves other silver-bearing minerals and the fineness of the resulting bullion is thereby lowered. Consequently, the fineness of cyanide bullion rarely corresponds to the true gold fineness and is useless for diagnostic purposes, although it is a common fallacy to refer to the fineness of cyanide bullion as the fineness of the gold.

Jan 1, 1950

By P Staples, G Lane, S Morrell

The design of semi-autogenous grinding (SAG) mill based comminution circuits for the treatment of competent ores, similar to those at Geita and Boddington, involves the same process of sample selection, test work, data analysis and data modelling/interpretation as that used for 'average' competency ores. However, over the past couple of years a number of issues have arisen that are common to the design of circuits for the comminution of 'highly' competent ores. The impact of these issues on project viability is generally more pronounced when treating hard ores than average to soft ores due to the greater impact on capital and operating costs. The issues encountered have included: standard test procedures have been modified; test equipment has worn or been damaged; different procedures yield different data and varying interpretation; and modelling and empirical calculations have been based on poor benchmarks, or used incorrectly in the case of JKSimMet, yielding misleading outcomes. The purpose of this paper is to present, discuss and clarify some of the issues associated with conducting test work and designing comminution circuits for the treatment of 'highly' competent ores in order to reduce thelevel of conflict arising from interpretation and application of test work data. Specifically, the issues associated with the bond crushing (impact) and rod work indices measurement, the various SAG mill specific energy tests, and the interpretation of the resulting data will be discussed in the context of case studies.

Jan 1, 2009

By C N. Whata

While there is no specific obligation on the part of any applicant to consult directly with tangata whenua (people of the land), recent cases highlight the need to engage in active consultation in order to avoid serious objections and delay, particularly where a proposal may affect the matters referred to in section 6(e) (Waahi tapu/sacred places) and 7(a) (KaitiakitangaiGuardianship) of the RMA.   The Environment Court has shown some sympathy for tangata whenua where waahi tapu and other significant matters of cultural concern are at risk because of a proposed development. There are several practical steps that can be taken to minimise the potential for serious objection including: ò knowing who to contact and how to contact them; ò demonstrating empathy for the concerns of tangata whenua; ò engaging in proactive consultation, for example meeting at a time and a place that is suitable to tangata whenua, and a preparedness to meet the costs of tangata whenua etc; ò demonstrate an awareness of tangata whenua issues; being aware of the types of mechanisms that are available to remedy, avoid etc adverse effects on matters of concern to tangata whenua.

Jan 1, 1997

By P Gunn, M Watts

The general goal of passive acid mine drainage (AMD) treatment is to reduce levels of acidity and metals to acceptable levels. Most treatment systems use either an oxidising or a reducing strategy. In oxidising systems, alkalinity is added along with dissolved oxygen; in reducing systems, dissolved oxygen is removed (if present) and then alkalinity is added. It is recommended that small-scale field trials be conducted as part of the methodology of selecting the best remediation strategy at AMD sites. Following successful field trials at the Sullivan Mine AMD, the Pike River Coal Company (PRCC) has shown foresight by using the same system to treat AMD generated as a result of taking a bulk sample of coal at the Pike River coal field. The system reduced acidity by 100 per cent, iron by 99 per cent, aluminium by 96 per cent, nickel by 95 per cent, manganese by 51 per cent and zinc by 99 per cent. The success of this field trial suggests that a system using a reducing strategy may be appropriate for the Pike River Adit AMD site.

Jan 1, 2005

Amongst the unavoidable studies of the mining engineer who desires to reach the maximum efficiency, is the subject of patents. With the fundamental principles of the patent laws of this and other leading countries he should of course befamiliar, but still more should he keep abreast of that practical knowledge which will enable him to act or advise wisely when the patenting of a new invention, or the sale, purchasing, or adoption of a new patented machine or process becomes amatter for consideration. As every engineer worthy of the name is an inventor and more particularly every mining engineer he has a direct interest in watching the progress of legislation and administration concerning patent monopolies.His worldly prospects may indeed, to a considerable extent, depend upon the defeat of bad patent laws and the removal of incompetent officials, or the appointment of better ones. Better patent administration is always in Australia a valid requirement, and until engineers generally take up and press the demand, bad administration is likely to continue. Even though every engineer is not a patentee, nevertheless his interests in patents must always be direct and powerful, and ignorance or apathy in regard thereto must inevitably injure either his own interests or those of his employer. When we consider the tens of thousands of mines scattered through Australia alone, on everyone of which there is expensivepatented machinery, and when we consider the thousands of...

Jan 1, 1901

The ~2500 km long Kermadec-Tonga arc northeast ofNew Zealand is the longest continuous intraoceanic arc in the world. At least 94 volcanic centres along the arc are submarine, most (87 per cent) within the Kermadec arc (de Ronde et al, 2003a). Volcanic rocks range from basalt to rhyodacite with trace element and isotopic data indicating significant magma source heterogeneity both along and across the arc.   The entire ~1300 km of the Kermadec arc has now been surveyed for hydrothermal emissions (de Ronde et al, 2004). First-stage surveys utilised surface vessels. In February 1996, the first sulfide samples from the southern Kermadec arc were dredged from the Brothers and Rumble II West caldera volcanoes (R/V Tangaroa cruise TAN96/03; Wright et al, 1998; de Ronde et al, 2003b). In September 1998, low-temperature, diffuse venting was discovered at Monowai, Rumble III and Clark volcanoes, and high-temperature, black smoker venting was found within Brothers caldera (R/V Sonne cruise SO-135; Stoffers et al, 1999). The NZAPLUME cruise of March 1999 surveyed 13 volcanic centres (each mainly comprised of single, large volcanoes) of the southern Kermadec arc and documented hydrothermal emissions above seven of them (de Ronde et al, 2001; Baker et al, 2003; Massoth et al, 2003). In July 2001, additional mineralised and hydrothermally altered samples were dredged from Brothers volcano (R/V Tangaroa cruise TAN01/07). The NZAPLUME II cruise of May 2002 confirmed venting was still occurring at all the known hydrothermal sites, and that ten active vent sites occurred along the mid-part of the arc, between Brothers and Raoul Island (de Ronde et al, 2002). In September-October 2004, NZAPLUME III surveyed the northern-most part of the Kermadec arc where another nine volcanic centres are hydrothermally active.   Second-stage exploration of the Kermadec arc hydrothermal systems utilised deep submergence vehicles. In October-November 2004, the Japanese submersible Shinkai 6500 made four dives on Brothers. Samples recovered include vent fluids, chimneys, altered rocks and various animals and microbes. In April-May 2005, a more extensive expedition using the American submersible Pisces V made 23 dives on nine different volcanic centres, eight of them for the first time.   Extensive plume surveys show Brothers volcano is host to the most hydrothermally active sites of all those known along the Kermadec arc. In total, nine dives have been made on Brothers, six on the NW caldera site and three on the cone site. The NW caldera vent site is a long-term hydrothermal system that is today dominated by evolved seawater but has had episodic injections of magmatic fluid. The cone site is a nascent magmatic-hydrothermal system where crack zones localise upwelling acidic waters (de Ronde et al, 2005). A SE caldera site represents the main upflow of a relatively well-established magmatic-hydrothermal system on the seafloor where sulfide-rich chimneys are extant. Each of these different vent sites represent diverse parts of an evolving hydrothermal system, any one of which may be typical of submarine volcanic arcs.

Jan 1, 2005

The presence of undetonated explosives in a rock face after firing constitutes a hazard which can result in a fatal or serious accident if undetected before drilling commences.Most accidents caused by drilling into explosives are the result of failure to examine the working face properly and lack of care in subsequent drilling operations; it is not always realized that explosive may be left in the butts of holes or may be driven into cracks or crevices in the rock.Obviously the best means of preventing accidents of this nature is to adopt methods of drilling, charging and firing which will reduce the hazard to a minimum.There are three ways in which undetonated explosives may be left in the rock face, namely:1. Misfires.2. Cut-off shots.3. Incomplete detonation or failure of the charge to propagate throughout.MisfiresNo attempt will be made in this paper to deal fully with the question of the prevention of misfires, as apart from the fact that most of the preventive methods are well known, it is believed that if the miner receives his explosives and means of initiation in good order, and proper care is taken in their use, the failure of a charge to fire will be a rare occurrence. The provision of central fuse capping stations on mines has gone a long way towards the elimination of misfires caused by the mishandling of safety fuse anddetonators.

Jan 1, 1956

Difficulties were experienced in the identification of carbonate minerals intimately associated with iron oxides in the so called carbonate ore, which occurs at depth in the Iron Duke Orebody.Determination of refractive indices by examination under the microscope using the immersion method, together with inferred chemical composition indicates that dolomite and parankerite are common constituents. Histograms of the manganese and sulphur contents strongly suggest that manganese is associated with the carbonate minerals, and that the highest sulphur assays occur near the base of the carbonate body.From the present work it is concluded that refractive indices indicate only a very approximate composition for carbonates of the parankerite type.The different carbonate minerals occur in irregular zones.INTRODUCTIONThe Iron Duke deposit is situated in the southern portion of the South Middleback Range on Eyre Peninsula, S.A., 30 miles from Whyalla. (Fig. 1).Drilling at Iron Duke revealed a large body of so called carbonate ore, which was tested in detail at cross section 1000 ft. S by three diamond drill holes, DDH.57, 67 and 78. (Fig. 2)Most specimens of carbonate ore described below were obtained from DDH 67 and 78.GENERAL GEOLOGYThe South Middleback Range is composed of two parallel ridges trending north-south. The Iron Duke orebody is situated on the southern portion of the western ridge. (Fig.1) .The rocks of these ranges belong to the Middleback Group which rests on a gneiss complex. Their age is considered to be Middle Precambrian or late Archaean.

Jan 1, 1963

The authors describe two stratiform intrusions within a two miles thick ophiolite belt, one of the many ophiolite (serpentine) belts of the eugeosynclinal sequences of the Kalgoorlie System (metamorphic age c.2700 million years). Unusually good evidence of gravitational differentiation involving cumulates for an Alpine type peridotite-gabbro intrusion has been obtained, in spite of modifications of the original igneous rocks imposed by regional metamorphism. Unmetamorphosed relics of cumulate rocks are a surprising feature of this occurIfence.'fhe differentiation process reflected in the layered sequences is compared to that of the Stillwater Intrusion, Montana. Phase, cryptic and rhythmic layering are recognized. The economic significance of this study lies not only in the possibility of nickel mineralization in this ophiolite belt, but also in that much detailed information on the nature of these belts, which is difficult to obtain in the case of the more altered and sheared rocks of the belts carrying gold and nickel ore deposits nearby, is gathered from the Yilmia occurrences.

Jan 1, 1969

Satellite Image Based Strategies to Evaluate the Impact of Dismissed Mine Site - An Application to the Mae Moh Coal Mine Area in the Lampang Province, Thailand

Sep 13, 2010