Applying spatial prospectivity mapping to exploration targeting: Fundamental practical issues and suggested solutions for the future

Abstract Despite many decades of development, spatial prospectivity modelling is not yet widely used or accepted throughout the global mineral exploration industry. A common criticism of the method is that it is not practically useful because it has a bias to mature, well-known areas and generates excessively large areas of high-prospectivity. It is suggested that the reason for this is not primarily related to limitations in the prospectivity mapping algorithms but rather to issues relating to the use of input data sets. Specifically, it is common that the input data (such as geological interpretations) do not uniformly and objectively represent the search space of interest, omit critical targeting-relevant geoscientific elements (such as major, deep-seated ore-controlling structures) and have a large degree of unrecognised dependence. It is considered that these problems are not in principle barriers to the eventual successful deployment of this technology. However, future approaches to spatial prospectivity modelling need to explicitly address these concerns. It is suggested that the most effective method may be a hybrid of subjective human geological interpretation and objective, machine-based analysis, that captures the best aspects of these alternative approaches; i.e., an intelligence amplification (IA) rather than an artificial intelligence (AI) approach. A roadmap is proposed for improving the effectiveness of spatial prospectivity modelling that has implications for the broader community interested in mineral exploration targeting.

[1]  J. Walshe,et al.  Metallogenic episodes of the Tasman fold belt system, eastern Australia , 1995 .

[2]  S. Thiel,et al.  The crustal geophysical signature of a world-class magmatic mineral system , 2018, Scientific Reports.

[3]  G. Partington Developing models using GIS to assess geological and economic risk: An example from VMS copper gold mineral exploration in Oman , 2010 .

[4]  E. O'driscoll Observations of the lineament-ore relation , 1986, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[5]  T. McCuaig,et al.  The mineral systems concept: The key to exploration targeting , 2017 .

[6]  V. Grauch,et al.  Geologic and geophysical evidence for the influence of deep crustal structures on Paleozoic tectonics and the alignment of world-class gold deposits, north-central Nevada, USA , 2002 .

[7]  S. Barnes Komatiite-Hosted Nickel Sulfide Deposits: Geology, Geochemistry, and Genesis , 2006 .

[8]  Magoon The petroleum system , 1989 .

[9]  F. Agterberg,et al.  Weights of evidence modelling: a new approach to mapping mineral potential , 1990 .

[10]  O. Kreuzer,et al.  Linking Mineral Deposit Models to Quantitative Risk Analysis and Decision-Making in Exploration , 2008 .

[11]  A. Porwal,et al.  Introduction to the Special Issue: Mineral prospectivity analysis and quantitative resource estimation , 2010 .

[12]  O. Kreuzer,et al.  Comparing prospectivity modelling results and past exploration data: a case study of porphyry Cu–Au mineral systems in the Macquarie Arc, Lachlan Fold Belt, New South Wales , 2015 .

[13]  T. McCuaig,et al.  Translating the mineral systems approach into an effective exploration targeting system , 2010 .

[14]  W. Griffin,et al.  Gold in the mantle: A global assessment of abundance and redistribution processes , 2018, Lithos.

[15]  Frederick P. Brooks,et al.  The computer scientist as toolsmith II , 1996, CACM.

[16]  V. Lisitsin,et al.  Orogenic gold mineral systems of the Western Lachlan Orogen (Victoria) and the Hodgkinson Province (Queensland): Crustal metal sources and cryptic zones of regional fluid flow , 2016 .

[17]  A. Porwal,et al.  Fuzzy inference systems for prospectivity modeling of mineral systems and a case-study for prospectivity mapping of surficial Uranium in Yeelirrie Area, Western Australia , 2015 .

[18]  V. Grauch,et al.  Geophysical and isotopic constraints on crustal structure related to mineral trends in north-central Nevada and implications for tectonic history , 2003 .

[19]  E. Carranza,et al.  Introduction to the Special Issue: GIS-based mineral potential modelling and geological data analyses for mineral exploration , 2015 .