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By L Brodie-Hally

In the early-1990s, Tad Golosinski, the former the head of mining department at WASM participated in a review mining engineering courses in Australia. The review team asked various industry executives what subjects they thought graduates needed to be taught. Tad made the comment to me that the more senior executives thought that history and ethics were very important. The outcome was that the mining engineering courses were required to contain at least five per cent content dealing in ethics. The course was to be modified to reflect this. Tad thought at the time the students would think that subjects dealing in history and ethics came from retirees and professionals that were over the hill. So let me talk to you today about ethics.

Jan 1, 2002

By E R. Ramanaidou

Two unknown iron ore samples were found by a geologist from Ok Tedi Mining Limited copper, gold and silver mine at an old wharf site dedicated to a 1970s drilling program in Lake Murray in Papua New Guinea (PNG). These iron ore samples could not come from a PNG mine and it was decided that a study should be undertaken to understand their origin. Lake Murray is the largest lake in PNG with a total surface area of 647 km2. It has a high-water 2038 km long convoluted shoreline with seasonal water level changes (Osborne, Kyle and Abramski, 1987) and it is located around 200 km south of the Ok Tedi mine (5°13’25”S, 141°09’37”E). The petrology, mineralogy and chemistry of two Fe samples (Ok Tedi 1 and Ok Tedi 2) included optical microscopy, X-ray fluorescence (XRF) analysis and a comparison with worldwide iron ore deposits. The two rock samples were cut to produce two subsamples: (1) a polished thin section; and (2) a pulp that was used for XRF analysis including major, minor and trace elements. Ok Tedi 1 and Ok Tedi 2 were petrologically and chemically compared to a range of known iron ore samples from Australia, Brazil and South Africa. The petrological study of Ok Tedi 1 indicates that it is composed of granoblastic recrystallised hematite and the overall texture is uniform without any obvious original ‘sedimentary’ texture. Ok Tedi 2 is a ‘specular’ or platy hematite with recrystallised and fused grains. Using both petrological and chemical clues, the two Ok Tedi samples likely originated from the Iron Quadrangle in Brazil.

Sep 18, 2023

By D Piason

Newstan Mine commenced mining operations in 1887 and has since undertaken extensive mining within the Young Wallsend, Great Northern, Fassifern, Borehole and West Borehole coal seams using a range of mining methods including board and pillar mining and longwall mining.Newstan Mine is planning to extend the existing mine workings using longwall and miniwall mining methods to produce up to 4.5 Mt/a of run-of-mine (ROM) coal for at least 25 years. The planned extension in the Main East and South West sections will involve developing new longwall panels and related mains headings. The new area contains higher specific gas emissions (SGE) than previously experienced at Newstan Mine. To achieve the optimum ventilation requirements for the longwall operation in this new area, a new ventilation shaft was designed to be constructed using the blind boring method in the South West Headings section.This paper presents the shaft design parameters and selection criteria for the construction of the new ventilation shaft, including the construction phase and the holing process to connect the shaft to the underground workings. The paper also discusses future ventilation requirements for Newstan Mine.CITATION:Piason, D, 2015. South-west ventilation shaft project at Newstan Mine, in Proceedings The Australian Mine Ventilation Conference, pp 229–238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

Since the early 1990s it has been evident that electricity demand has outstripped investment in generation and transmission. At the same time, concerns were being expressed about the risks associated with the run down of the Maui gas field. It is axiomatic that the necessary investments firstly require a stable and supportive regulatory and fiscal environment, and secondly that such investments have long lead times. A unwillingness by successive Governments to fund the necessary infrastructure, however, lead to the profound restructuring of the electricity with the ultimate objective of transferring the investment risk from Government to the private sector. Successive power crises since 1992 result from a failure to put in place a regulatory framework necessary to provide the environment to allow the private sector to make the needed investments within the necessary timeframe. The electricity sector has now stabilised to the extent that the regulatory risks associated with generation investment have been reduced. This does not mean that risk has been eliminated, however, and both economic and environmental issues will continue to constrain investment in some power proposals particularly those in the South Island and especially any South Island coal or gas thermal proposal. This is firstly because of several very simple economic issues:  1. while the South Island may have significant coal resources it lacks a significant electricity market; 2. except for a six to ten week period in a dry year, low cost hydro will price any large-scale South Island thermal out of the market which will restrict any large scale thermal station to a dry year and/or peaking load; 3. except for a six to ten week period in a dry year, export capacity on the HVDC link to the North Island is constrained to around 964 MWe (and 482 MWe from North to South in dry years); and 4. construction of any new thermal plant in the northern half of the North Island will price any South Island thermal station out of the market. There are also significant environmental issues associated with the establishment of a large scale thermally based power station in the South Island. Because the South Island lacks any large scale economically proven gas reserves, the environmental constraints considered are those associated with coal production. A coal mine dedicated to power generation will have significant on-site impacts associated, in particular those associated with disposal of opencast overburden and visual impacts. These will, however, be partially offset by the relative remoteness of such sites to population centres. What cannot be offset, however, is the off-site impacts, in particular, CO2, SOx and NOx emissions, water disposal and acid mine drainage.

Jan 1, 2003

By F Hungerford, T Ren

"Gas management has always been a major concern for the ventilation officer of any gassy mine. With an increase of mining depth and gas content, there is a great demand for the development of in-seam drilling sites where boreholes can be drilled for the pre-drainage of gas prior to longwall operation. The ventilation and gas management in the drilling site therefore becomes a critical component of mine safety. In this study, advanced computational fluid dynamics technology was adopted to investigate the aerodynamics of gas emitting from the drilling site and boreholes during normal drilling and, in the case of a sudden gas inrush, from the borehole. In addition, the impact of different ventilation controls on gas removal in the drilling site was investigated. Modelling results indicate that gas accumulation zones could be formed if the ventilation system fails to deliver sufficient airflow to the drill site, especially when a sudden gas inrush from a borehole occurs. The configurations of brattice, layout of ventilation tubes and the gas emission rate all have a significant effect on the gas distribution. Due to variations in site-specific conditions, it would be desirable to conduct modelling studies to assess the effects and efficiencies of a ventilation design for the varying environment on-site before carrying out drilling practice. CITATION: Ren, T, Hungerford, F and Wang, Z, 2015. Computational modelling studies of ventilation management for underground in-seam drilling sites, in Proceedings The Australian Mine Ventilation Conference, pp 239–250 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 31, 2015

By Ito H, Noguchi F, Ueda Y

DTA curves of synthesis lead sulfide and commercial. lead concentrates during oxidation were measured to clarify the mechanism of ox- idation of lead sulfide. The oxidation reac tions could be divided to elementary reactions with production of basic lead sulfates such as 2PbO PbSO4. An existance of iron sulfide played an important role of the oxidation of lead concentrates. The oxidation rates of lead sulfide were measured in the wide range of oxygen potenti- als using IR type SO2 gas-meter. The oxidation rates under low Po 2 which corresponds to the direct oxidation smelting were much lower than those obtained under high Pot. The combustion temperatures of lead sulfide were also measured by hot thermocouple method. Those values were extremly low compar- ing the oxidation temperatures obtained by DTA.

Jan 1, 1987

By P Dowd, A Adeli, C Xu, X Emery

Geometallurgical modelling is increasingly being incorporated into mineral resource modelling and estimation as a means of increasing efficiency, decreasing operating costs and reducing risk in mining operations. Traditional geostatistical workflows for geometallurgical modelling face several difficulties, in particular, related to the non-additivity of process response variables, to highly heterotopic data sets and/or to preferential sampling designs, all of which may explain why most attempts to estimate geometallurgical response variables from assay data and mineralogy are still based on statistics and machine learning. The aim of the work presented here is to demonstrate the applicability of geostatistics to estimate copper recovery from copper sulfide ores at the Prominent Hill Iron Oxide Copper-Gold (IOCG) deposit in Australia. As recovery is non-additive, the preferred workflow is the joint estimation of the masses of metal in the feed and in the concentrate, both of which are additive variables. While the mass of metal in the feed can be estimated from abundant online assay analyses, the mass of metal in the concentrate can only be estimated from a very limited number of laboratory-scale batch flotation tests. Traditional approaches to estimating the masses of metal in the feed and in the concentrate, such as simple and ordinary co-kriging, are described and discussed. A modified version of co-kriging is introduced, which incorporates linear relationships between the mean values of the input variables, in addition to a spatial correlation model. Co-kriging with related means is shown to outperform traditional simple and ordinary co-kriging in terms of precision, accuracy and consistency of the estimates, and offers a practical and efficient tool to deal with highly heterotopic and preferential sampling designs.

May 24, 2023

By M Scoble, E Rubio

The re-engineering of manufacturing production systems has demonstrated the benefits from using production information for optimising processes. This paper explores the techniques and issues in the acquisition and analysis of mine production data for tactical decision making in production control. The use of information and operations management tools is presented in the context of block caving studies, with particular focus on the relationship between secondary breaking and LHD production performance.

Jan 1, 2000

By D-J Min

Strategies and achievements in the Asian steel industry to construct industrial ecological chain are reviewed largely in the case of Japan, Korea and China. Emphasis is placed on the development of resource circulatory system for the minimisation of various wastes and emissions of green house gases (GHG), toxic gases and polluting particulates. The minimisation includes:Rationalisation of iron and steelmaking processes; Implementation of available relevant measures/technologies; Life cycle assessment in designing steel from semis to assembled products; Reduction, reuse and recycling of materials and energies; and Utilisation of core competence technologies to process domestic and industrial wastes. In view of global nature of the above wastes- and emission-issues, inter-industrial linkage and international cooperation across the borders in the Asian countries have become more important. Inter-industrial linkage definitely serves to cut back the wastes and emissions. Examples of such linkage and factors influencing the sustainability of the linkage are described with expectation for further development of the linkage. Importance of international cooperation cannot be overstressed under the circumstances where steel production in China exceeded 220 Mt and world production exceeded 945 Mt in 2003 and is still increasing. Practical measures are discussed to enhance the linkage and cooperation for effectively promoting the reduction, reuse and recycling, including implications for the nonferrous industry.

Jan 1, 2004

By L Dubron

This study details a mineralogical and textural characterisation of West African iron ores with an emphasis on their behaviour during mineral processing. By means of both qualitative and quantitative characterisation, a simulation of the beneficiation process applied to these iron ores is performed. A series of different analytical tools are used, including:X-Ray Diffraction (XRD) for qualitative mineralogical analysis;• qualitative optical microscopy (phase identifi cation, description of micro-textures) and (semi)• quantitative optical microscopy (counting of particles, phases and textural types); and• chemical analysis.All the information provided by these analytical methods are combined into a quantitative mineralogical and textural analysis, here called ‘modal analysis’, which enables us to simulate the capability of West African iron ores to be benefi ciated by magnetic and gravimetric separation techniques.On one hand, both qualitative XRD and optical microscopy have revealed the presence of the following mineralogical phases: magnetite, haematite, goethite and quartz. On the other hand, the chemical analyses provide us with quantitative inputs expressed as oxides. We have converted the oxides into mineralogical contents expressed as magnetite, haematite, goethite and quartz. In this way, we build a simple quantitative mineralogical analysis.Beside this, the semi-quantitative approach of the characterisation by optical microscopy also provides us with a liberation study, enabling us to split the gangue-bearing content between two types of particles:1. liberated gangue-bearing particles, and2. composite particles composed by both iron (oxhydr) oxides and gangue-bearing minerals.We have assumed that we could anticipate the behaviour of these two kinds of particles through a mineral process, by simulating the removal of at least the liberated particles of gangue. Optical microscopy also revealed a trend in the weathering profi le of the Tokadeh ore horizon with a decrease from bottom to top of magnetite and an increase of both goethite and martite showing a higher level of oxidation and hydration in the upper ore horizon.We have applied this removal extent upon the quartz content of the mineralogical quantitative analysis and we have re-calculated the quantitative mineralogical analysis considering the expected decrease in the quartz content. Finally, by converting the re-calculated (oxhydr) oxides contents into iron grades and summing them, we do obtain a fi nal simulated iron grade for the upgraded products.

Jul 11, 2011

By S Hapugoda, Y Tang, L Lu

The steel industry is one of the global leading CO2 emitters, accounting for approximately 7 per cent of global anthropogenic CO2 emissions. In 2022, the world produced 1878.5 Mt of crude steel. About 70.8 per cent of the world’s crude steel was produced by integrated steel mills through the blast furnace and basic oxygen furnace (BF-BOF) process, while the remainder was produced largely by mini mills using electrical arc furnaces (EAF). Compared with gas-based DRI and scrap-based EAF processes, the direct CO2 emissions from the BF-BOF process and the coal based DRI and EAF process are significantly more, as both the processes rely heavily on fossil fuels, such as coke and pulverised coal, to provide energy and reduce iron oxides. Hydrogen is very reactive and reduces iron oxides to metallic iron without generating CO2. Therefore, substitution of hydrogen for fossil fuels in these processes presents a good opportunity to significantly decarbonise the steel industry. This paper will first discuss the thermodynamic and kinetic characteristics of hydrogen and carbothermic reductions of iron oxides and then examine the behaviours of different ore types present in Australia iron ores during hydrogen reduction.

Sep 18, 2023

By Lawson F

Chrome chemicals are commercially produced by the alkali roasting of the chrome-bearing ore chromite with sodium carbonate. In order to ascertain the influence on the extent of reaction of the replacement of Mg(II) for Fe(II) in the chromite spinel structure and the presence of acidic oxides in the gangue material, a series of roasting experiments was conducted using chromite materials from a number of different locations. The roast feeds and products were chemically analysed and the major compounds identified using X-ray diffraction and scanning electron microscope techniques.Mg(II) replacement for Fe(II) in the chromite structure does not appear to restrict the amount of "available" chromium for reaction.Under the test conditions, namely an atmosphere of pure oxygen, finely ground chrome-bearing material, a roast temperature of 950°C and the stoichiometric amount of sodium carbonate to react with the chromite, the yield of water-soluble sodium chromate was able to be expressed as %yield = 104.5 -1.58 × %AI2O3 - 2.23 × %SiO2 for chromite samples containing alumina in the range 7.8 to 27.8 per cent and silica in the range 2.9 to 7.4 per cent.

Jan 1, 1984

By R Strand, B Usher

Environmental compliance and mine designs are increasingly including assessment of flows and water qualities as a key driver to decision-making over life-of-mine. Integrated site-wide water quality models linked to dynamic water balances have been used for regulatory submissions, feasibility studies, operating mines and mine closure studies. These models, developed in GoldSim, link aqueous chemistry to the physical system of the site-wide water balance. Geochemical mechanisms included are determined from geochemical characterisation and site water monitoring, depending on the data availability at each site. External geochemical modelling using PHREEQC, version 2 (by D?L?Parkhurst and C?A?J?Appelo) and Geochemists Workbench (GWB), (by C?M?Bethke and The Board of Trustees of the University of Illinois) identifies the most important geochemical processes to be included in the model as a series of geochemical mechanisms which include source term loading rates, pH-buffering and equilibration of water quality. Water balance components include seasonal flow variability; waste facility water storage and system lags; run-off variability; milling processes and tailings production as a function of ore types; simulation of automated and scheduled maintenance of settling ponds; water re-routing for water treatment and freshwater demand, usage and storage.Case studies illustrating the use of these models for regulatory submissions and mine feasibility studies in a variety of climatic and regulatory environments show the utility and applicability of these models. Site-specific examples of these models developed by Klohn Crippen Berger Ltd are currently used at operating mines across the world. One of the larger mines where this is used is a mature poly-metallic mine in South America where the model has aided mine managers in understanding how various planned initiatives and potential water options will result in changes to flows and water quality. It is used regularly to inform water and waste management to minimise impacts to the receiving environment as a consideration of both flows and concentrations. The mine has also used the model in support of water treatment design, regulatory submissions and mine closure planning.Further examples of feasibility and operational/compliance assessment in arid and strongly seasonal environments for planning, regulatory and closure consideration of mine wastes and pits have shown the utility and usefulness of these approaches for a range of mining operations at various stages of mine life.CITATION:Strand, R and Usher, B, ?2014. Integrated site water balances and water quality models for decision-making over life-of-mine, in Proceedings Life-of-Mine 2014 , pp 271–284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Han Kook-Nam, Lawson F

The recoveries of the three cobalt minerals in the Mount Cobalt deposit, cobaltite CoAsS, erythrite CO3(AS04)8H20, and new cobalt mineral with a composition approximating 2CoO.CaO.Fe203.2As205.11H2O were investigated using physical and surface-chemical processes.Over 80 per cent cobalt recovery was achieved by tabling a cobaltite-mineralized sample, while about 76 per cent cobalt recovery was obtained by dry feed magnetic separation of a sample containing erythrite and the new cobalt mineral. The resultant primary magnetic concentrate with a cobalt grade of 5.5 per cent, was able to be upgraded to 14.4 per cent cobalt by regrinding .and a further magnetic separation.Electrophoretic mobility - pH responses for each of the three cobalt minerals were found to be similar. Each mineral remained negative over the pH range 3 to 11 and was most negative at mildly alkaline pH values.Cobaltite was floated effectively with amyl and ethyl xanthate collectors under acidic conditions at collector concentrations of 10-2M to 10-5M. Erythrite showed a similar flotation response using 10-sM amyl xanthate. The practical application of these laboratory separations to an industrial process is suggested.

Jan 1, 1976

By M Wortley, J McKay, D La Rosa, O Guyo

It has been a generally held concept that crushing operations were, by their nature, too simple to benefit from the implementation of advanced process control. The commissioning of an OCS¬ expert control system and image-based oversize detection system, VisioRock, at the Pilbara Iron Tom Price facility are dispelling these notions. A constraint-based OCS¬ expert control system has been designed and commissioned on the high-grade crushing and screening plant along with a vision-based oversize detection system functioning on six product conveyor belts. To date, the expert control has demonstrated the ability to increase production by maximising dynamic constraint utilisation. Dynamic constraint utilisation is a concept developed by Rio Tinto Technical Services for effectively evaluating constraint-based control logic performance. The VisioRock system has been installed and configured and has been operating for a period of several months. Currently, Tom Price and Metso personnel are working to define correct oversize detection thresholds. Details of the plant implementation are discussed.

Jan 1, 2006

By J Rowland

"Ventilation models are invaluable tools for both prediction of routine daily ventilation changesin an operating mine to circuit performance expectations at the mine in 20 yearsÆ time. Arguably ventilation offi cers are becoming increasingly reliant on maintaining an accurate ventilation model with which to do their work. This paper relates to the practical assessment of the accuracy and thus ability of a mine site ventilation model to be reliably utilised on such varied tasks. The author's experience shows that in some cases the incumbent model is found to be in a state of tune that demonstrates a mine wide detailed assessment of branch resistances is simply not required. The money spent on a detailed mine wide ventilation survey that is not required would be far bett er served purchasing much needed monitoring equipment, rather than fixing something that is possibly not even broken. The term ænot rocket scienceÆ has been incorporated into the title of this paper because it appears that many practitioners believe that circuit validation is diffi cult. As long as clear att ention to detail is paid to the actual data collection process then drawing an accuracy comparison between the circuit performance and the model performance at any particular point in time, is really very simple. This paper will show a manner in which a circuit can be analysed to determine its actual state of health by using various diagnostic tools and tips. It will help ensure that subsequent work scopes to address any highlighted model defi ciencies can be more effi ciently scoped and targeted. It will hopefully remind operational people that such self assessments can easily be done æin houseÆ if the appropriate steps are followed."

Jun 1, 2012

The new law on Environmental Protection and Management (Republic of Indonesia Law 32 of 2009) was passed by the Indonesian parliament in September 2009. This law aims to protect Indonesia's rapidly degrading environment by providing tougher provisions for both polluters and law enforcers. In doing so, the law introduces a number of new constraints and potential business risks that will affect all companies in Indonesia, particularly mining companies. Some of the newly introduced concepts follow.   Mining companies will now require an environmental license, issued by the Minister of Environment or local counterparts. This license is a prerequisite for all other business and operational permits. The Minister can revoke the environmental license at any time in case of an environmental incident or dispute. Mining companies may be exposed to additional environmental taxes and bonds besides already existing reclamation and mine closure bonds.   There is an increased risk of environmental lawsuits, due to more stringent controls on one side and greater protection for NGOs on the other side who make claims, false or true, against the company. Company executives and managers can be sued and they will be held accountable if environmental degradation has indeed occurred due to the company's activities.   Companies may face increased liabilities due to a change in the definition of contamination. The new definition is more stringent (and on occasion may prove too stringent to be practical); it also provides little room for flexibility in its application.   As implementing regulations are prepared over the coming two to three years, mining companies will need to adjust to the new law. A proactive approach is needed to minimise risk. Recommended actions include: upgrading existing environmental impact assessments to a higher standard; conducting baseline studies and thoroughly documenting environmental conditions on a regular basis; closely tracking regulatory changes, especially the forthcoming implementing regulations on the new environmental law; and regularly engaging key government and community stakeholders on environmental issues.

Jun 1, 2010

By A Jyoti, J R. Black, R R. Haese, E O. Ansah

Copper (Cu) is a critical metal in the transition to a low-carbon power supply. Presently, low-grade copper sulfide ores account for almost 80 per cent of the global reserves. Large amounts of water are required to process these low-grade copper ores. The mining industry utilises lixiviants from recycled water from different sources to conserve water, whilst enhancing Cu recovery. Some utilise intermediate to pregnant leach solutions, sea water, and processed water from electrowinning circuits with highly variable concentrations of ions. Previous studies have highlighted the formation of precipitates that passivate the surfaces of minerals in these low-grade copper ores and/or block flow paths for lixiviant during heap leaching. In this study, we utilised concepts of phase replacement to devise an innovative means of controlling precipitation and increasing copper recovery using industrial brine as opposed to freshwater. We propose the formation of Al-rich phases (such as AlSO4 + or alunite) to replace iron sulfate and iron hydroxysulfates (such as jarosite) during the chalcopyrite dissolution-precipitation mechanism. The rationale is to have available Fe3+ throughout the chalcopyrite leaching process. We tested this method by carrying out various batch experiments using CaCl2, AlCl3, and NaCl industrial brine types compared to freshwater and explored the capacity to leach Cu from chalcopyrite. There is higher Cu recovery during oxidative leaching of chalcopyrite in industrial brine with 91 per cent recovery using AlCl3-rich brine, 84 per cent with NaCl-rich brine, and 56 per cent with CaCl2-rich brine as compared to 35 per cent recovery using freshwater. In the absence of Al3+, various forms of iron sulfates, and jarosite are formed, reducing the availability of Fe3+ for chalcopyrite dissolution. The introduction of Al3+ leads to the formation of AlSO4 + species, thus lowering sulfate activity and the tendency for K-jarosite formation.

Aug 24, 2022

The mmmg operations carried out by North Broken Hill Limited, necessitate the use of four shafts for the haulage of ore, men, and supplies. These are:-1. Blackwood's Shaft.-British Section, which has 100 feet intervals between levels to the bottom 800 feet level plat;2. Thompson's Shaft.-British Section, which has 100 feet intervals between levels to the bottom 1400 feet level plat;3. No. 1 Shaft.-With intervals between levels:(a) 100 feet to the 800 feet level,(b) 150 feet from 800 feet level to the 1700 feet level;4. No. {2 Shaft.-2770 feet from collar to bottom plat, with intervals between levels: (a) 100 feet to 800 feet level, (b) 150 feet from 800 feet level to the 2600 feet level. (c) 170 feet from 2600 feet level to the 2770 feet level.All shafts have two cage compartments, and the No. 2 Shaft a skip installation in addition.For the control of hoisting operations an electric signalling system is installed on each shaft, and is supplemented by a counterbalanced rope pull ("Knocker line") operating a surface gong. The latter system is shown diagrammatically in Fig. 1.Two sets of electrical equipment are used per shaft. The first, shown in Fig. 2, is that operated by the braceman or...

Jan 1, 1940

By W Dodson

Major ions, d18O and d2H and Carbon-13 concentrations in groundwater from 30 bores near an open pit iron ore mine were used to better understand the chemical evolution of groundwater in the aquifer. The relatively depleted d18O and d2H isotopes of groundwater from various depths suggest that groundwater is recharged from intense rainfall events, with little evaporative effect. The 300 to 500 mg/L increase of major ions relative to that of rainfall is due to evapotranspiration of rainfall during recharge. Geochemical mass balance modelling suggests that the evapotranspiration of rainfall during infiltration through the unsaturated zone varies over six fold from 20 to 130. This coupled with the dissolution of CO2 from the unsaturated zone and partial dissolution of carbonates and gypsum from Tertiary sediments and carbonates from the Wittenoom Formation accounts for the current major ion, d18O and d2H distribution in groundwater. Despite the relatively dissected morphology and steep hydraulic gradient the results of this study highlight the dominance of vertical flow relative to horizontal flow. The study also shows the dominance of rapid recharge by significant rainfall events as an important component of the water budget for east Pilbara aquifers.

Jan 1, 2009