s

If you have a GIS program, spreadsheet and the will (perversity?), you can “explore” this stuff for yourself.

DATA SOURCES & COMMENTARY

One of Australia’s outstanding strengths as a mineral exploration destination is its world class Government maintained

public domain mining tenement, historical exploration record and geoscientific data. Queensland has excellent digital

data, records and metadata freely available to the public for download over the internet.

Historical exploration tenement GIS layers and data are available for most of the other states but they vary in suitability

for time series analysis. NT historical exploration data does not currently have grant dates so can’t be used. The huge

number and arcane details of WA mining tenement data make it difficult to deal with. One persistent bugbear is

inconsistent data fields and labels between current and historical tenement records.

Major differences in mining regulations also make direct statistical comparison of tenement number and area statistics

between some states difficult. SA’s exploration tenement system does not require routine reductions as per the

majority of jurisdictions. In this presentation some comparisons are made between QLD & NSW due to the similarity of

the exploration tenement regulations and data. There are also broad geological and commodity production similarities

between the states –they constitute Australia’s black coal exporters.

Australian Bureau of Statistics (ABS) data is available for download as spreadsheets and is derived from returns of self-

assessment questionnaires sent to all Australian mineral and coal exploration tenement holders. The data is very useful

but has a number of potential ambiguities and inconsistencies. Whilst expenditure by commodity class and old/new

project is recorded at the state level, curiously drilling meterage is not. This is unfortunate as drilling statistics

categorised by states and territories would be invaluable data. For this presentation evening the following sources

provided bulk of the data for processing and analysis.

Historical metal prices and indices used are real $US derived from the World Bank datasets available for download.

1. Australian Bureau of Statistics (ABS) - 8412.0 - Mineral and Petroleum Exploration, Australia http://www.abs.gov.au/ausstats/abs@.nsf/mf/8412.0

2. Queensland Government Data: * Exploration Permit for Minerals - Queensland * Mining Leases – Queensland *Mineral Development Licence – Queensland * Mining Claims – Queensland * Historic Exploration and Production Permits – Queensland * Historic Mining Leases – Queensland https://data.qld.gov.au/dataset/queensland-mining-and-exploration-tenure-series * Mineral Resource Sites - Queensland * Queensland surface and drill-hole geochemistry database. * Queensland geology GIS https://data.qld.gov.au/dataset/queensland-coal-petroleum-mineral-occurrence-series https://www.business.qld.gov.au/industries/mining-energy-water/resources/geoscience-information/digital-data/exploration-geochemistry https://www.business.qld.gov.au/industries/mining-energy-water/resources/geoscience-information/digital-data/geological-mapping

3. World Bank Commodity Price Data (the ‘Pink Sheet’ – thanks to Rio Tinto Exploration) http://www.worldbank.org/en/research/commodity-markets#1

DATA PROCESSING METHOD

Mapinfo-Discover and Excel were used as the primary software platforms for processing, analysis and display.

In QLD, the development of exploration permit (EPM), mining lease (ML), mineral development (MDL) and mining claim (MC) time-series were based on current and historical GIS layers downloaded as shape or Mapinfo tab files. Current and historical GIS datasets have different data fields and level of information. Current EPM/MDL/ML/MC GIS files are up to date and scrupulously maintained. The current tenement files have more extensive data and high accuracy boundary polygons. The historical GIS datasets have less data, are less frequently updates and have greater question marks over accuracy of permit boundaries. Conversion of A to P to EPM numbers has been taken as is.

Fortunately both current and historical GIS datasets contain have near complete grant and expiry dates which facilitates time-series analysis. Downloadable historical GIS layers do not currently contain holder identities but this information is available by specific request from QDNRM.

Current and historical GIS data layers with grant, expiry and holder data can them be rationalised, harmonised, merged and stripped of duplicates and null records. Following “clean up” and merge, using mid-June current EPM data, a file with 14,402 historical and current EPMs was produced. Historical EPM data extends back to 1954.

The merged file is time sliced by year by using batched Mapinfo queries to produce a set of year on year GIS layers. Spherical areas of mapped polygon outlines for each year are also batch calculated for each record. The queries are constructed in a way that all EPM’s that existed at any time during the target year are included in the records.

The same process is followed for ML, MDL and MC files and a merged file of all produced.

In total there were 18,783 current and historical EPM, ML, MDL and MC records in the cleaned-up and merged all tenement type master file.

Individual GIS files containing all EPM’s that existed in any year are spatially combined to minimise any double counting of areas that are overlapping in the single year file. Analysis of non-combined and combined (overlaps removed) totals show very little difference, so combined and non-combined data can be used equivalently in time-series.

Individual year GIS layers are exported and recombined in Excel for grouping and graphing using pivot table operations.

Mineral resource sites and drill-hole locations from the geochemistry series have also been referred to. Following editing and removal of coal, aggregate, and stone occurrences a file with 17,845 entries was used.

Merging of the geochemistry series drill-hole data yielded a merged file with 110,024 collar locations across QLD.

METHOD LIMITATIONS & POTENTIAL MERITS

The work is painstaking and involves a variety of data format merges and software operations where mistakes are possible. Whilst much effort has been taken to ensure accuracy of the data plots they should be regarded as provisional drafts requiring third-party scrutiny to ensure higher confidence – caveat lector. If you really want to be sure go get the data and process it yourself!

One of the major logical limitations of the method is that the historical GIS layers/data only contain the dimensions of individual tenements at the time of grant, there is no information on any subsequent reductions. The current tenement layers differ in that they show the actual size of the individual tenements which may have been reduced from the original grant size. Therefore, combining historical and current tenement files does involve merging different types of dimensional data. However, since current EPMs comprise only 10% of the merged tenement file records and several current EPM’s will yet to be reduced the mismatch effect is likely very small. Due to the “original grant size” dimensionality of the bulk of the data the annual tenement areas totals will be consistently maximums. Compiled and summed data for areas granted per year do not suffer from these effects and are likely inherently more accurate.

The potential merit of exploration tenement statistics is that they are derived from scrupulously maintained Govt. sources, independent of vested interest, self-assessment or accounting practice. Exploration tenement, by regulation, should also reduce the ambiguity inherent in using “exploration expenditure” as the key metric – what’s exploration and what’s development spend? It is for these reasons it was decided to investigate exploration tenement date aggregation as an alternative means to measure and analyse historical and current exploration industry trends. Ultimately further investigation and use will demonstrate its ultimate effectiveness.

The determination of the historical EPM time series and other plots will also be fundamentally limited by the accuracy of the source file EPM polygons and date records.

D. Brewster July 2017 Associate - Aussam Geotechnical Services Limited Corresponding email address: brewster.doug@gmail.com