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By A J. Gunson

The Norman B Keevil Institute of Mining Engineering, or the Department of Mining Engineering (the Department), at CanadaÆs University of British Columbia (UBC) is addressing the integration of sustainable development concepts into mining education and research on behalf of industry and society. Over the past decade, the DepartmentÆs education and research model has been evolving to incorporate collaborative and multidisciplinary strategies, where sustainability initiatives are taught in classes, supported in research and discussed in a voluntary collective of mostly graduate students û the Sustainability Working Group (SWG). The SWG has brought together a diverse array of disciplines from academia, industry, government, non-governmental organisations (NGOs) and mining communities. The operational mechanisms and structure of the SWG have enabled momentum to be gained through several multidisciplinary educational and research networking initiatives. It acts to attract new students with diverse backgrounds, foster innovative research, develop relationships and networks, and create the space to discuss progressive ideas and projects. The original cohort of SWG graduate students laid the foundation for sustainable research initiatives within the Department at UBC. Novel research has incorporated topics such as: community resilience, artisanal small-scale mining, sustainability indicators and corporate social responsibility, environmental assessment and impact benefit agreements and the recycling of waste. Propelled by the support of the Department and inspired by the works completed, a host of new graduate students have embarked on their research quests to integrate sustainability principles into their projects. Such projects include: social impacts and benefits of mining, artisanal small-scale mining, community health, the production and transport of mine pollutants, mine waste management, mineral process plant design and the evolution of community education and mine policy. This paper reports on the departmentÆs continuing research and development towards an understanding and evaluations of the ongoing contributions of mining to sustainable development.

Jan 1, 2009

By N Boughen, K Moffat, L Brooks, A Zhang

In 2015, Ernst and Young (EY) ranked socio-political license to operate (SPLTO) as the fifth greatest challenge to the mining sector (EY, 2015). The EY report asserts that SPLTO will continue to present a risk to the mining sector in the context of ‘increased activism, digitally connected stakeholders and politicians who need to respond to general consensus’. While there is no consensus on a definition, SPLTO is commonly regarded as the ongoing acceptance or approval of an operation by affected stakeholders (Moffat and Zhang, 2014; Thomson and Joyce, 2008) as well as those stakeholders that can affect the operation (Graafland, 2002). Warhurst (2001) relates the process of stakeholders granting SPLTO to the establishment of meaningful partnerships between operations, communities and government based on a variety of factors that build trust between stakeholders.From these accounts, we can see that understanding stakeholder attitudes about company performance and impacts on stakeholders directly affected by an operation are important in any attempts to measure SPLTO. Understanding the level of acceptance of an operation within these stakeholders provides a good proxy or outcome measure of SPLTO. Moreover, trust seems to be a central variable in the translation of these experiences of an operation into acceptance. What the mine or company does, its behaviour, degrades or builds trust with stakeholders, and this then affects acceptance (Moffat and Zhang, 2014).In addition, a strong emphasis is placed on the nature of the relationship between companies and stakeholders as influenced by inter-group interactions. It is not just what companies do well or poorly with respect to environmental impacts, for example, that will determine trust and acceptance, but how the company relates to its stakeholders at personal and group levels.These relationships between communities of stakeholders and extractive companies are dynamic. Brown and Fraser (2006) recognised the importance of industry being able to respond to the changing nature of societal approval and acceptance, arguing that ‘business must have regard for evolving social attitudes and expectations if it is to maintain its ‘social licence’’.This paper will describe a series of five pilot projects conducted by CSIRO with Anglo American in Australia and South Africa to generate a real-time understanding of SPLTO to guide more reflexive and effective social performance strategies.CITATION:Moffat, K, Boughen, N, Brooks, L and Zhang, A, 2016. Social licence in real-time – using dynamic methods to support a new kind of community relationship, in Proceedings Life-of-Mine 2016 Conference, pp 191–194 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

The efficient and profit-maximising daily and long-term management of the Vera Nancy resource depends on decisions based upon assay data. This paper examines the range of sample sources, the methods of sample collection, assay techniques and Quality Assurance used by the mine. The orebody has a relatively low nugget effect for a gold mine (around 25 per cent) and this greatly assists in reducing sampling error and producing reliable assay data for production decision-making. Reconciliation between mine and back-calculated mill grades generally sees the mine under-calling mill grades by around four per cent.

Jan 1, 2000

By S Talu, E Savage, P Sturm, A van As

It is estimated that substandard ground support installations and elements cost the Rio Tinto Copper Group millions of dollars between 2000 and 2014. These issues have also created significant safety and financial risks in Rio Tinto mines. As a result, Rio Tinto Copper has developed CaveCAD, an integrated system to collect, store and analyse all ground support-related data. The CaveCAD system stores geotechnical data and has the ability to automatically import data, collect data through tablet applications, report processed/analysed data and present this data through 3D visualisation software.The CaveCAD Ground Support module closes the design–implementation–verification loop by providing a method of verifying the compliance of all installed ground support, recording manufacturer specifications, recording quality control test compliance and rectifying any non-conformant areas. The module uses innovative technology to create value through cost saving, safety improvements and data collection efficiency. Cost savings will be achieved by a decreased need for excavation rehabilitation, less ‘waste’ due to faulty installation and quality assurance checks reducing the likelihood of substandard support units being used. Data collection will be improved through the use of a mobile tablet application that can be used underground in ‘off-line’ environments.CITATION:Savage, E, Talu, S, Sturm, P and Van As, A, 2016. Development and implementation of the CaveCAD ground support module for cost and safety improvements in block cave mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 769–772 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Y K. Ji, B J. Chung

In recent years, the utilisation of ultra-fine ore in ironmaking has gradually increased due to the depletion of high-quality iron ore. The use of ultra-fine ore in the ironmaking process is typically energy intensive and leads to high CO2 emissions. The improvement of sinter reducibility is one of the methods used to reduce the environmental impact of using fine ore.In this study, a high-strength and high-reducibility sinter manufacturing process was investigated by controlling the sintering reaction. The key technology used in this method is the manufacture of mini-pellets by selective granulation equipment. The mini-pellets consist of iron ore, limestone and burnt lime and are designed to melt at temperatures below 1200°C. The molar ratio of CaO to Fe2O3 of the mini-pellets is 0.25~0.75. The 2~5 mm diameter mini-pellets are manufactured with burnt lime as the binding material.During the sintering of mini-pellets, goethite, which has relatively high reducibility, should be retained as residual ore in the sinter cake. The strength of the sinter cake was kept by the bonding reaction of the mini-pellets, which have a low melting temperature. This is the main principle of the reaction-controlled sintering method.The reaction-controlled sintering method manufactures a high-strength and high-reducibility sinter cake and increases sinter productivity by around 15 per cent using ultra-fine iron ore.CITATION:Chung, B J and Ji, Y K, 2015. Production of high-quality sinter by controlling the sintering reaction, in Proceedings Iron Ore 2015, pp 21–28 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By D J. Williams, G W. Wilson, S, A B. Tran

A comprehensive field program was implemented to evaluate the internal structure and hydrology of two full-scale waste rock piles. The excavation of waste rock dumps for in-pit disposal at the two mine sites provided an opportunity to characterise the in situ properties of the dumps given contrasting geologic and climatic settings. The internal structure and materials within the dumps were observed and sampled as the waste rock piles were being excavated and placed in the open pits for permanent closure. The field program was designed to fully characterise the structure and material properties of the waste rock. The alteration of the material by physical and chemical weathering was also observed. Samples were analysed for paste pH, water content, grain size distribution and geochemistry. In situ density and matric suction were also measured. Soil water characteristic curves and saturated hydraulic conductivity were measured for representative materials. These properties were used to predict seepage pathways through the waste rock and the resulting outflow geochemistry using the finite element model SEEP/W. The materials in the dump at Site 1 were predominantly fine-grained in texture and highly weathered. The presence of dipping beds with alternating coarse and fine materials was evident throughout the profile of the dump. The structure of the waste rock appears to have an impact on the hydrologic pathways within the waste rock pile. The material in the dump at Site 2 was found to be competent and resistant to particle size breakdown. The particles range in size from clay size to large boulders with the median particle size being approximately 125 mm in diameter. The coarse-grained texture of the waste rock resulted in a loosely packed arrangement of coarse particles with little matrix material infilling the pore spaces between the coarse-grained particles. Seepage modelling for Site 1 was completed to predict seepage paths based on observed structure and hydraulic properties measured in the laboratory. The modelling showed that materials with a fine grain size distribution become the dominant pathways for flow through the waste rock pile. The modelling also showed that layers with high silt and sand contents are subject to the highest flow rates. Finer grained clay rich layers have a low hydraulic conductivity and do not convey large volumes of water. Alternately, coarse gravel and cobble materials are unsaturated under values of matric suction that approach the residual water content of the material and do not transmit liquid water. The seepage modelling together with the results of the geochemical analysis show that the dominant particle size that receives the most fluid flow and flushing ranges from fine sand to silt, corresponding to materials with air entry values ranging between 5 kPa to 50 kPa.

Jan 1, 2003

A new engine family has been developed by Caterpillar Tractor Co. for application in off-highway trucks. This family, the 3500 Series is available in three configurations, covering a 600-1200 kilowatt range. This engine series incorporates the latest in design technology, stringent functional specifications for servicing ease, fuel economy, reliability, optimum performance and parts interchangeability. TECHNICAL INTRODUCTION The 3500 Series Engine has been under development by Caterpillar for over eight years and has undergone extensive testing in the laboratory and in field prototype units. - The engine configuration is a 600 Vee in 8, 12, and 16 cylinder versions. - The intermittent power output per cylinder is 75 kilowatt (100 HP). Net power for off-highway trucks is 600-1200 kilowatt (800-1600 Hp) depending on engine configurations. The 3512 (3500 Series Engine 12 cylinder Vee configuration) was the first model of the 3500 Series released. These engines offer optimum user value in terms of product durability, reliability, fuel consumption, performance and installation flexibility. Additional features of 3500

Jan 1, 1982

An Integrated Geology-Mine-Plant and Eco-Efficiency Simulator for Anglo Platinum's Evaluation and Operational Improvement Initiatives

Sep 13, 2010

During the later part of 2007 I was lucky enough to visit the Atlas Copco facilities in Sweden, and to see first hand what a large and diverse company Atlas Copco is. The reason this paper calls the Atlas Copco experience a bonanza is that it means a source of great and sudden wealth or luck; a spectacular windfall or a rich mass of ore, as found in mining. I think this aptly describes the scholarship as it has greatly increased my wealth of knowledge of the mining industry. This paper intends to encourage all those eligible to apply for this fantastic scholarship opportunity, and seeks to thank all those involved who made this scholarship the amazing experience that it was. Atlas Copco produces most of its Swedish products in the town of +rebro, and it was here that I spent most of my time, visiting the Underground Rock Excavation group, the Surface Mining Equipment group and Rocktec. I also travelled around Sweden and was able to visit one of OricaÆs manufacturing plants, the Secoroc groupÆs manufacturing plant, the Geotechnical Drilling and Exploration group as well as being fortunate enough to visit the LKAB mine in the Arctic Circle in Sweden. The trip was not all information on Atlas Copco products and services however; I was able to go to the Ice Hotel in JukkasjSrvi and drink Absolut Vodka out of ice glasses, go on a reindeer safari (as well as eat them!), sample the fine meat from a moose, drink local schnapps, attend the Atlas Copco Christmas party, wander around the wonderful city of Stockholm and generally immerse myself in the great Swedish culture.

Jan 1, 2008

Sizing is fundamental technology for each step of ironmaking process. The progress of sizing technology has greatly contributed to the development of ironmaking technology. As the purposes of ironmaking operations diversified particularly since the oil crisis of 1973, the sizing technology made new advance- ment, as represented by pulverization of ser- pentine, dezincification and classification of secondary blast furnace dust, pulverized coal injection, size-segregated sinter charging and a coal preparation control process. These techniques are mostly characterized by the fine grinding of a given type of mineral or coal to heighten the degree of reaction con- trol. This trend is expected to continue Further.

Jan 1, 1984

By R J. Goldie

The Monty Copper Gold Deposit is an ultra-high grade mine in Sandfire Resource’s Doolgunna region which was completely drilled out and developed within two years of commencing mine development. During this period, a total of 986 grade control diamond drill holes were completed, assayed, and validated, 15 levels developed, and 3136 faces mapped. The aggressive schedule meant a high flow of geological data was produced, validated, and incorporated into regular geological model updates. To process this data at a rate which allowed for timely use, more robust data processing methodologies needed to be generated. A new validation system was implemented which required two levels of validation being applied to any diamond drilling update. Step one was the validation of initial physical data including survey pick-ups and logging. This was done prior to new drill data being added to the geological model. Step two was the validation of assay data which was required prior to resource estimation. The implementation of Seequent’s Leapfrog Geo modelling software also allowed for a more seamless and efficient modelling workflow. The use of the Leapfrog Geo vein systems allowed for more rapid generation of geological models which then afforded more time for stringent assessment of the mineralisation system. An example of this was the introduction of cross-shift peer reviews in which opposing rosters of geologists would rigorously evaluate the previous rosters work prior to reporting. This additional level of validation resulted in more robust geological models and the identification of new ore trends. This presentation will detail the evolution of the Monty Geological model from a simple tabular indicated resource into a complex highly refined measured resource. Themes will include how the model was produced using workflows developed and optimised to meet key deliverables.

Mar 22, 2022

SOME 70 miles south-east of the of Auckland lies the town of Waihi-the centre of the Waihi goldfield, at present the mining pride of New Zealand. That the glory of most mining camps is evanescent forms an axiom to which it may be expected Waihi will prove no exception. For the last fifteen years, however, Waihi has been an important gold-silver producer, with an annually increasing output, so that now the area ranks as one of the leading goldfields of the world.

Jan 1, 1911

By H Kurth, L Balzan

The potential for bulk diversion was identified and quickly implemented following the development of bulk sensing technologies applied to conveyed flows. In the early 1980s real time analysis of ash in coal was intended to improve the understanding and control of quality variability. By the end of the 1980s approximately 5% of coal analysers installed were being utilised for bulk sorting; diverting flows to create stockpiles to improve blending flexibility and boiler feed consistency, diverting waste material, or bypassing the beneficiation process when the coal met product quality criteria. In the 1990s bulk sensing and sorting utilising natural gamma detection was applied to conveyed waste in gold-uranium mineralisation and allowed ore to be recovered and processed that would otherwise have been discarded. Further applications developed in the iron ore sector where product quality ore could be diverted to bypass beneficiation and save significant unnecessary processing costs and improve recovery by avoiding process inefficiency losses. Plant capacity was freed up to be utilised by material that required processing. Similar benefits became evident in the phosphate industry and in base metals where multi-elemental analysis using Prompt Gamma Neutron Activation Analysis provides ideal opportunities to representatively measure 30 second conveyed increments at high accuracies. This has been successfully adopted in copper, nickel, platinum and lead-zinc to improve waste removal after primary crushing to eliminate unnecessary expense and improve plant efficiency. The benefits include increased output from existing operating capacity, significant reductions in consumable costs and generation of fewer detrimental waste streams. The paper outlines the technologies and discusses case studies covering the above commodities, demonstrating the immense value that representative real time measurement of conveyed flows can create. Measurement data concurrently provides multiple benefits in operational performance besides sorting, through ore reconciliation, ore blending, feedforward control and metal accounting, adding further value.

Nov 10, 2020

By H Allday

The mining industry’s attention has shifted over the last decade with the recovery from the downturn resulting in greater development of innovation and new work methods in a bid to remain competitive and deliver higher productivity. The emphasis on cost reduction to improve profit margins has primarily been the focus of the “work smarter” campaigns embraced within the industry. But is this strategy holistically the best-for-business, or does it place a ceiling on revenue opportunities and inhibit mining companies from truly maximising value? Businesses need to maintain a balance between active cost management and revenue generation often resulting in cost reduction strategies at site level. These strategies have merit, assessing areas of cost wastage across operations and creating space for opportunity. However, this potentially can create distractions from the goal of enabling growth and lead to the sacrifice of quality and delivery. Focusing too heavily on cost reductions without addressing revenue generation is an unprofitable lens to look through, and the relationships between cost, revenue, quality and profit margin can often be overlooked resulting in missed opportunity to maximise value. How these relationships are effectively employed by mining companies to reap the rewards from an overarching corporate perspective down to site level remains a fluid concept depending on the nature, operating market and strategy of the business. A common directive from businesses to their operations is to strive for greater profitability and productivity. The quantification of these requirements, and the nature of the cascading message delivered, impacts the methods employed by the operational team to meet the expectations of the business. Cascaded strategies, if not delivered with appropriate participation and buy-in can often be perceived to be knee-jerk and create frustration for operations who are squeezed to deliver on expectations by slashing site costs. This squeezing is not only felt by the mining operation but at the individual level and can result in increased team stresses. In some cases, this may also steer behaviours towards activities that result in corner cutting and an elevation of operational risk, potentially increasing associated incidents and injury. Driving down costs by any means can create an unhealthy tunnel vision where value is no-longer assessed for best-forbusiness results. By flipping the viewpoint to a value-based approach revenue opportunity may be realised and potentially exceeded, however this opportunity may be missed if value is over shadowed by a cost heavy focus. By analysing a selection of real operational cases (ranging from mining contractors through to in-house mining giants), it becomes apparent that practical revenue maximisation strategies are not only key to an increase in value and cash flow but to a stronger understanding of business drivers for sites and operators alike. In the cases evaluated additional revenue opportunities are foregone in favour of cost reduction strategies resulting in negative impacts on the associated operations and wider businesses. Alignment towards value generation is king. If strategies are not implemented focusing towards value and revenue maximisation, the opportunity loss experienced by mining operations could continue be great and the question should be posed; when the next up-turn hits will operations be ready to reap the rewards or still have a glass ceiling above their heads?

Mar 15, 2021

By A N. Parry, G van Wyk

"Sensor based automatic ore sorting technologies are used in the minerals industries to efficiently remove waste and submarginal grade material from crushed and screened run-of-mine (ROM) ore, producing a coarse (typically >10 mm) upgraded preconcentrate at an early stage in the mineral processing circuit. This avoids additional energy intensive downstream processing of this rejected component of the ROM feed, leading to lower unit operating costs and reduced tailings disposal volumes.Test work on bulk low-grade gold ore stockpile samples from Central Norseman Gold Proprietary Limited has been conducted, indicating high gold recoveries as well as high material rejection rates. A financial model, based on these results, evaluates grade sensitivity and identifies a minimum stockpile grade for adequate financial returns. The base case modelling estimates that the ex-stockpile grade (including the fines bypassed fraction) can be more than doubled through ore sorting and that the project will be highly viable with strong cash flow generation at stockpile grades as low as 0.7 g/t gold. The modelling will enable the company to benchmark ore sorting options against stockpile reclaim and screening operations currently employed. Citation:Parry, A N and van Wyk, G, 2016. Upgrading Low-grade Gold Ore Stockpiles by Preconcentration Using Ore Sorting - an Assessment of the Economic Impact and Viability, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 179–190 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By S Szylkarski, D N. Graham

In mining, water management is an operational necessity, requiring planning and detailed engineering, as well as risk assessment. Yet, the hydrology of streams and aquifers typically extends well beyond the boundaries of mine operations and intersect with environmental and social values. Mine managers often plan, design and assess the impact of water management activities (such as dewatering, excess water disposal and flood management) with a mine site or process specific focus. The challenge is that the impacts are spatial, long-term and complex – and may be cumulative across multiple mine sites. Further, there is usually little consideration of the feedbacks and interactions between surface water, groundwater and catchment hydrology. Failure to understand these processes can lead to poor decisions and increased costs. This presentation outlines an approach to simulating integrated hydrology in mining catchments that addresses the shortcomings of traditional modelling techniques.CITATION:Graham, D N and Szylkarski, S, 2016. Simulating integrated hydrology in mining catchments from planning to closure, in Proceedings Life-of-Mine 2016 Conference, pp 101–105 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By R Dunne, W McCallum

Continuous improvement might be defined as seeking incremental improvement over time through improved equipment, processes, technology and the efforts of people. Most people working in ore processing facilities embrace the general principles of continuous improvement. However, given the industry-wide issues with skilled personnel and the constantly changing environment in ore processing facilities, it is often difficult to identify improvements in a facility over a given time period. The driver for these outcomes is the use of basic principles and technology to achieve best practice targets. The process involves four stages: develop standards of practice to define best practice in specific areas; write procedures to guide the organisation towards these best practices; implement the procedures and develop a review process to provide a method of measuring performance against best practice.By reviewing performance against best practice on a regular basis, the organisation measures progress towards the best practice targets and the incremental improvement between these regular reviews is a measure of continuous improvement.This paper provides the background for developing standards of practice for metal accounting, metallurgy and metallurgical management. The paper also describes how standards of practice can be used to develop continuous improvement and the skills set of the departmentÆs leadership team.CITATION:McCallum, W and Dunne, R, 2012. Metallurgical management tools for continuous improvement, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 225-230 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Mauk JL, Arehart GB

Quartz veins from the Martha Hill epithermal gold-silver deposit, Waihi, commonly exhibit crustiform banded textures. Visual differences observed between bands are primarily the result of a 1 to 1500 ¦m variation in quartz grain size. Quartz band textures are dominated by anhedral interlocking quartz mosaics, commonly associated with minor adularia and sulfide phases; these textures are interpreted to be products of amorphous silica crystallisation. The occurrence of rhombic adularia suggests that prolonged boiling influenced parent fluids. In contrast, the presence of coarsely crystalline bands, made up of subhedral to euhedral quartz grains, infers primary crystal growth from solution; evidenced by the occurrence of growth-zoned quartz within these bands. There is a narrow range of 3.3%o in 618Oq,,,,,= between maximum and minimum isotopic values for the deposit. Significant overlap in 618Oqu,, values are observed between the Martha and Welcome lodes. However, statistically significant and commonly systematic differences do occur between individual bands analysed in most samples. Temperature fluctuations may be the dominant factor responsible for observed inter-band variation.

Jan 1, 1995

By H Cifuentes, D J. Williams

Despite the recognised importance of tailings management, there remain little data on the potential benefits of biological treatments compared with physical and chemical treatments. The operation of the majority of tailings storage facilities (TSFs) continues to employ mainly physical solutions, such as sub-aerial tailings slurry deposition, with increasing adoption of thickening, paste and filtration to dewater the tailings involving the addition of chemicals such as flocculants and coagulants. However, with tailings production continuing to escalate rapidly due to the increasing demand for commodities and reducing ore grades, available technologies have not demonstrated cost-effective performance at high tailings production rates. This paper examines the emerging role of bacteria to better manage tailings, reducing risks and optimising storage capacity. Bacteria have the potential to enhance tailings dewatering, maintain their permeability, delay the onset of desiccation cracking, and improve their shear strength. Bacteria-treated tailings may be suitable for use as construction materials. Bacteria also have potential in limiting the dusting of tailings and facilitating rehabilitation on closure. The paper describes a series of laboratory involving the addition of harmless bacteria to a range of tailings. The bacteria form a compact material called calcite (a common and stable form of calcium carbonate), which immobilises the tailings particles, releases water, and cements the tailings in a stable and natural matrix. The water released can be recovered or evaporated, depending on site objectives. The bacterial reactions are linked to physical and chemical processes, providing the potential for an optimal mix of technologies for particular tailings and site conditions.CITATION:Cifuentes, H and Williams, D J, 2018. Potential improvement of tailings geotechnical behaviour using bacteria, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 228–238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By T Blyth, D Holden, N Archibald, S Huffadi

The Morning Star mine is owned by Hill 50 Gold NL. Gold is hosted in quartz-carbonate ¦stibnite ¦molybdenite veins that occur in a series of deformed, altered and metamorphosed mafic volcanics with subordinate sediments and felsic intrusive rocks. The irregular gold distribution and its relationship to structure and alteration intensity makes the definition of stoping limits difficult. Understanding the structural evolution of the orebodies and the contemporaneous and later structures that affect the orebodies has been very useful in this context. This paper reports on a detailed mapping exercise (as part of a more extensive and on-going investigation) and the integration of this mapping with other geological and grade control data in a 3D modelling environment to provide an expanded basis for stope design. Three types of mineralised zones can be discriminated based on the morphology of the veins within. They are:those associated with strongly folded, thick veins (approximately 1 m thick eg 05 orebody); those comprising planar, boudinaged and some folded veins which consolidate to form tabular, steeply dipping bodies (eg 010 orebody); and zones containing the above vein types and thin, highly deformed veins within zones of intensely foliated country rock that result in localised, irregularly distributed high-grade gold zones (eg 02 orebody). The mineralised zones associated with thick folded veins are typically predictable over many tens of vertical metres. The second and third types of ore zone is generally less predictable. Detailed mapping and structural kinematic studies indicate all ore zone types are affected by progressive deformation involving strong strain partitioning. It is interpreted that high strain zones, recognisable by intense foliation development and highly deformed veins, are the latest stage of a progressive deformation which approximates bulk flattening. Structural controls on mineralisation can be defined at two different scales.Regional scale folding has deformed a sequence of mafic volcanics with interlayered sediments and felsic intrusives. Initial geometry of felsic bodies relative to orientation of the primary lithological layering and the bulk shortening direction is interpreted to be critical for initiation and development of strongly dilatant zones within this package of rocks, and Local scale dilation is evidenced by development of several vein sets whose range in orientations and opposed vergence relationships suggest a pre-folding origin comprising both extensional and hybrid shear-extensional types. Continued deformation resulted in folding of these veins with strong strain partitioning. Major vein packages are closely spatially associated with the felsic/mafic contact and an interpreted early structure which appears to have partitioned early dilation. This structure is now obscured by strong deformation but is currently represented by a zone of planar veins.

Jan 1, 2000