Application of remote sensing and GIS mapping to Quaternary to recent surficial sediments of the Central Uranium district, Namibia

The arid conditions in the study area within the central Uranium district of the Namib Desert are suitable for remote sensing analysis. This research applies integrated remote sensing and GIS methods to various datasets including ASTER and Hymap hyperspectral, and includes field-validation to differentiate between previously undifferentiated Quaternary to Recent surficial sediments. Comparative assessment of the remote sensing and GIS derived geological datasets is performed, and field mapping used to the constrain results. In conjunction with the integrated mapping, the distribution of uranium in the area through natural processes such as wind and fluvial systems, as well as factors associated with mining and exploration are investigated. In addition to baseline geological data, the study provides useful information for the understanding of secondary uranium mineralisation, and for environmental monitoring of uranium activity

Knowledge-driven mineral potential modelling: applying the Mineral Systems Approach to the west Kimberley, Australia

Regional prospectivity analysis of the west Kimberley has been undertaken using the results of geophysical structural interpretation and the mineral systems approach (MSA) to mineral potential modelling. Ore deposits are small expressions of much larger Earth processes and systems focusing mass and energy flux at multiple scales. The MSA provides a framework within which metal sources, fluid transport mechanisms and traps can be recognised and represented by predictor maps. Predictor maps act as proxies for mineral system processes and include distance to a particular geological feature, locations of rheological and chemical contrast, structural complexity and location of mantle-tapping structures. The approach to mineral potential modelling taken here combines different predictor maps in a knowledge-driven inference framework order to identify likely zones of mineralisation. Nickel-sulphide analysis indicates that the Inglis Fault and Yampi Fold Belt localises areas of increased mineral potential. Carbonate-hosted base metal prospectivity is restricted to regions overlying basement highs in the Lennard Shelf. A buried NW extension of the Oscar Range interpreted from geophysics is identified as a region of high mineral potential. Gold potential is mostly associated with the Inglis Fault, the Yampi Fold Belt and the central portion of the King Leopold Orogen. The centre, west and east of the King Leopold Orogen and parts of the Yampi Fold Belt show small, but high, regions of mineral potential for stratiform-hosted base metal deposits. The northwest and east of the King Leopold Orogen show small regions of tin-tungsten mineral potential. Intrusion-related base metal mineral potential is restricted to the Wotjulum Porphyry in the Yampi Fold Belt and the northern central part of the King Leopold Orogen

Future Understanding of Tectonics, Ores, Resources, Environment and Sustainability (FUTORES) II Conference: abstract volume

With the increasing world population and living standards the demand for mineral and energy resources continues to grow. Future exploration will need to target resources at increasing depths and in areas with cover, and will require an improved understanding of mineral and energy systems and advances in exploration methods and approaches. The Economic Geology Research Centre (EGRU) at James Cook University has organized the FUTORES II conference to summarise recent developments in the exploration and understanding of major types of mineral deposits, to examine the key issues and techniques critical to future minerals and energy exploration, and to discuss the way forward. The conference is being held in tropical Townsville, Queensland, Australia, on 4-7 June 2017. It is following on from the inaugural and highly successful FUTORES conference held in Townsville in 2013.FUTORES II will bring together researchers, explorers and government agencies to address issues related to the sustainable supply and utilisation of mineral and energy resources. The conference has three symposia: the David Groves Symposium - New Insights in Mineral Deposit Understanding, the New Technologies and Approaches in Mineral Exploration Symposium, and the Tectonics, Basins and Resources Symposium. The conference is convened by EGRU, an organisation that was established in 1982 to strengthen the links between research and exploration, to promote exploration-oriented research, and to facilitate knowledge transfer. EGRU has a track record of organising successful major conferences to facilitate the exchange of knowledge and ideas and to stimulate new ideas for cutting-edge research and exploration. The Hydrothermal Odyssey conference in 2001, and the STOMP (Structure, Tectonics and Ore Mineralization Processes) conference in 2005, both attracted over 200 participants. In 2009 EGRU collaborated with the SGA to host the tenth biennial SGA conference in Townsville - Smart Science for Exploration and Mining - which attracted over 480 delegates from around the world. In 2013 the first FUTORES conference attracted around 250 participants from 15 countries. FUTORES II is looking to be equally successful and has so far attracted around 265 registrants. This conference abstract volume contains 134 abstracts covering a wide range of topics related to mineral and energy resources, tectonics and metallogenesis. The abstracts have been reviewed and edited by the Editorial Committee and, in this volume, are organised in alphabetical order of the first author. We thank the delegates for their abstracts and the reviewers for ensuring the quality of the abstract volume

Uncertainty in GIS-based prospectivity mapping in greenfields and undercover terranes

Given the potential for the discovery of significant mineral deposits in greenfields terranes, as well as undercover, the methods used for GIS-based prospectivity mapping must be examined and adapted to address the challenges faced with exploration in these regions. As the quality of a prospectivity map can be dependent on both the understanding of a mineral system as well as the quality and quantity of the input datasets, the issue of how to quantify uncertainties must be addressed. Uncertainties may arise from the mathematical models used, data quality issues, and human bias. While mathematical uncertainties can generally be quantified using different statistical measures, it is more difficult to quantify the uncertainty related to human bias and data quality. Different methods for data interpretation and analysis are investigated to reduce the degree of uncertainty and to measure this value in a quantitative way when undertaking a prospectivity mapping exercise

Mineral potential mapping in frontier terrains

A successful targeting of potential mineralization in frontier terrains using mineral potential mapping in a GIS presents many challenges. There is often a lack of available data, data tends to be of poor or questionable quality, data are typically not digitized and may demonstrate incomplete data coverage. Additionally, a lack of available literature and research on known deposits with which to derive models or train data sets may further limit progress. Using both data-driven and knowledge-driven mineral potential mapping techniques, these challenges have been overcome through careful selection and refining of the training data (mineral deposits), as well as upgrading critical geological datasets (evidential layers) in order to generate country-scale mineral potential maps for orogenic gold deposit targets. The success of these mineral potential maps is measured by their ability to predict known deposits, which allows for validation of the results

Application of fractal and multifractal analysis to mineralized systems with special reference to the Mount Isa Inlier

Previous studies have suggested that controls on mineralization can be inferred from fractal analysis of mineral deposit distributions. However, many of these potential controls have been suggested on a qualitative rather than a quantitative basis. Whereas fractal analysis of mineral deposit distributions simply considers the location of the deposits, multifractal analysis can examine variation in values of attributes assigned to each deposit location such as deposit size. Yet no comprehensive study of the multifractal properties of mineral production data has been presented.\ud \ud Coupled deformation and fluid flow modelling has been used to verify sites of importance for mineralization in both two- and three-dimensional modelling space.\ud Numerical modelling in three-dimensions of strike-slip faulting has yet to fully examine the effect of variation in fault geometry. Quantitative analysis of model outputs can provide criteria for ranking of different fault geometry parameters in terms of their relative prospectivity.\ud \ud The Proterozoic Mount Isa Inlier is a rich base metal province in northwest Queensland,\ud Australia. As a well studied and well mineralized terrain, with comprehensive literature, and detailed geological and mineral deposit databases available, the Mount Isa Inlier is an ideal study area for investigating and verifying new techniques for brownfields exploration targeting. A quantitative examination of the controls on base metal deposition in the Mount Isa Inlier has substantial implications for future exploration in the region, with the techniques being readily applicable to other study areas and commodities.\ud \ud A new method is presented which evaluates mineral occurrence distributions by combining fractal analysis of clustering with Weights of Evidence (WofE). Variation in clustering of copper occurrences from the Mount Isa Inlier has a strong positive correlation with variation in clustering of fault bends (R=0.823), fault intersections (R=0.862), and mafic intrusions (R=0.885). WofE analysis as quantified by contrast values indicates that the copper occurrences have a strong spatial association with fault intersections, and fault bends. Correlation of the variation of clustering of copper occurrences and geological features shows a linear relationship with the contrast values indicating that the geological features controlling the clustering of the copper occurrences may be the same features controlling their localization.\ud \ud A fractal dimension can be used to quantify geological complexity, which characterises the distribution of faults and lithological boundaries. Two-dimensional analysis of geological complexity in the Mount Isa Inlier suggests that there exists a strong spatial relationship between geological complexity and copper endowment (R=0.914). A weak inverse relationship exists between complexity gradients and copper endowment. The results indicate that geological complexity could be used as an exploration targeting tool\ud for copper in the Mount Isa Inlier.\ud \ud The de Wijs model was developed to describe the distribution of element enrichment and depletion in the crust. An expansion of the de Wijs model is presented to investigate the distribution of ore tonnage as well as grade. The expanded model produces a log-normal relationship between ore tonnage and grade. Multifractal analysis suggests that ore tonnage values from the expanded model are not multifractal. Analysis of production data from the Zimbabwe craton displays a log-normal relationship between ore tonnage and grade, and indicates that ore tonnage is not multifractal, as suggested by the expanded de Wijs model.\ud \ud Variation of fault bend and fault jog system geometry parameters during coupled deformation and fluid flow modelling of strike-slip faulting reveals that having a low dipping fault, a contrast in lithology and a wide fault width generates the highest dilation and integrated fluid flux values which can be considered proxies for prospectivity. It is demonstrated that little difference is seen between the results obtained for restraining and releasing fault bend and fault jog geometries. The fault geometries observed in the modelling to be the most prospective could be incorporated into exploration targeting strategies

Addressing challenges with exploration datasets to generate usable mineral potential maps

Mineral potential mapping using GIS can pose many challenges in terms of data availability (eg. non-existent information, lack of digital data, limited understanding of mineral system) and data quality (eg. inaccurate locations or attributes, inhomogeneous mapping detail, incomplete coverage). As the quality of a mineral potential map is limited by the quality of the input data, it is affected by data availability and quality. These challenges are not limited to frontier or greenfields regions, but are the issues are often compounded by having multiple problems within the same dataset, which is uncommon in datasets from more explored and data-rich areas. Using several case studies, this analysis shows how mineral potential mapping can be successfully applied in regions with multiple data challenges in order to generate targets with high potential for hosting a mineral deposit. The data is evaluated using multiple statistical techniques, and the results validated by their ability to predict the location of known mineralization

Prospectivity mapping in a frontier region: a case study from Mongolia

The quality of a prospectivity map is dependent on the quality of the inputs used in the analysis. In regions with little to no exploration history, datasets are often of questionable quality, incomplete with information missing due to incomplete mapping or data simply not being available over certain areas. This study investigates how a data-driven technique for GIS based prospectivity analysis can be used to overcome such challenges for targeting potential mineralized areas. Using data from Mongolia, an iterative weights of evidence method is used to evaluate potential orogenic gold mineralization

Fluid flow in 3D strike-slip fault systems

[Extract] This study illustrates the effect of varying fault geometry using a three-dimensional finite difference code, whereas previous studies focused on two-dimensional models. Utilizing an existing GIS fault database of the Mount Isa Inlier, the most common trend of the major structures in the Western Succession was found and set as the default geometry for the numerical models

Mineral potential mapping in frontier regions: a Mongolian case study

The quality of a mineral potential map is dependent on the quality of the input data used in the analysis. In frontier regions or those with limited or no exploration history, datasets are often of questionable quality, and are generally incomplete with data missing either due to incomplete mapping or data not being made available to the public. This study introduces a method for addressing these challenges in mineral potential mapping to derive exploration targets. Utilizing four established statistical measures, an iterative weights of evidence method is employed to assess the strength of the relationship between known deposits and a set of geological feature layers. This method acts as an indirect validation tool for assessing the quality of the data by allowing an expert user to determine whether the statistics conform to expected relationships. Taking data from Mongolia, this iterative weights of evidence method is used to produce a mineral potential map and to evaluate potential targets for orogenic gold mineralization. The success of the method is determined by the ability of the mineral potential map to predict the location of the known mineralization.\u