Part of the responsibility of the Geological Survey of NSW (GSNSW) is to understand which areas of NSW have the greatest potential to host significant mineralisation. The challenge is to distil the vast knowledge and data available into a scientifically defendable map that can be used for:

  • land-use planning and advice
  • improved mineral system studies, including global endowment estimations
  • reduction of exploration risk, through the generation of targets and prospective tracts.

Creation of a mineral potential map is a predictive science that requires in-depth knowledge of how deposits form, and applying statistical modelling using high quality geoscientific data. GSNSW will be generating predictive GIS (2D) models for each significant mineral system in all NSW basement provinces. The key output is a Mineral Potential Data Package for each province. Each data package will contain all the GIS data used to produce the mineral potential maps for each mineral system.

Geoscientific data used in the models

Mineral deposit models are used to define modelling parameters applied in the analysis. The input variables include a complete array of data relating to ore formation, arranged into temporal stages of the mineral system process - including metal source, fluid source and pathways, migration to trap and deposit preservation. The common types of data used by GSNSW for the modelling are:

  • mineral occurrence data, including deposit locations, alteration descriptions, attributed deposit types, and vein structural data
  • basement geological data, including rock units and structural data
  • fault data, attributed with age, type and order
  • geophysical data layers, including magnetics, gravity and radiometrics
  • geochemical data, including drillhole, stream sediment and surface samples
  • igneous metallogenic fertility for granites and volcanic rocks
  • distribution of chemically reactive rocks (for example, black shales and carbonate units)
  • regional metamorphic data
  • field observations.

Southern New England Orogen mineral potential

The first province to be tested was the southern New England Orogen. This province was analysed for three potentially economic mineral systems: intrusion-related Au, intrusion-related Sn-W, and orogenic Au-Sb. Spatial modelling experts Kenex Pty Ltd were engaged to work with GSNSW's Mineral Systems section to perform the analysis. They employed a robust weights-of-evidence approach to the task, which resulted in the creation of between 71 and 101 predictive maps for each mineral system, distilled down to 18 maps for the final models.

Related reports

Left: Study area of the southern New England Orogen within NSW.
Right: Intrusion related Sn-W potential map for the southern New England Orogen.

Left: Intrusion related Au potential map for the southern New England Orogen.
Right: Orogenic Au potential map for the southern New England Orogen.

Zone 54 — Curnamona Province and Delamerian–Thomson Orogen mineral potential

Four significant mineral systems were analysed in the Zone 54 mineral potential study. These were: Broken Hill type Pb-Zn-Ag and iron-oxide copper–gold in the Curnamona Province and orogenic Au and volcanic-associated massive sulfide in the Delamerian–Thomson Orogen of the Koonenberry Belt. Spatial modelling experts Kenex Pty Ltd and GSNSW's Mineral Systems section used a weights-of-evidence approach, creating up to 132 predictive maps for each mineral system, and included up to 14 maps for the final models.

Related reports

Zone 54 in NSW showing the Curnamona and Delamerian-Thomson Orogen (Koonenberry Belt) study areas.

Left: Curnamona Broken Hill type Pb-Zn-Ag mineral potential map.
Right: Curnamona iron-oxide copper-gold mineral potential map.

Left Delamerian-Thomson Orogen orogenic Au mineral potential map.
Right: Delamerian-Thomson Orogen volcanic-associated massive sulfide mineral potential map.

Eastern Lachlan Orogen mineral potential

Five mineral systems were analysed as part of the eastern Lachlan Orogen mineral potential study. These were: Ordovician–earliest Silurian porphyry copper–gold and related systems of the Macquarie Arc; volcanic-associated massive sulfide systems in middle Silurian–Lower Devonian deep-water basins; Middle Devonian and early Carboniferous orogenic gold systems; and Silurian to Carboniferous granite-related skarn systems. Spatial modelling experts Kenex Pty Ltd and GSNSW's Mineral Systems section used a weights-of-evidence approach, creating up to 229 predictive maps for each mineral system, and included up to 11 maps for the final models.

Related reports

Left: Map of eastern Lachlan Orogen study area showing the location of the
mineral occurrences used to train the data-driven mineral potential models.
Right: Porphyry Cu–Au mineral potential map for the Macquarie Arc.

Left: Silurian to Carboniferous polymetallic skarn mineral potential map for the eastern Lachlan Orogen.
Right: Kanimblan Cycle orogenic Au mineral potential map for the eastern Lachlan Orogen.

Left: Tabberabberan Cycle orogenic Au mineral potential map for the Lachlan Orogen.
Right: Volcanic-associated massive sulfide mineral potential map for the eastern Lachlan Orogen.

Central Lachlan Orogen mineral potential

Three mineral systems were analysed as part of the central Lachlan Orogen mineral potential study. These were: Silurian–early Devonian granite-related Sn–W systems, Cobar Cu–Au systems related to magmatism in the late Silurian–early Devonian in the Cobar Superbasin and Cobar Pb–Zn systems related to inversion of the Cobar Superbasin in the Middle Devonian. Spatial modelling experts Kenex Pty Ltd and the GSNSW Mineral Systems section used a weights-of-evidence approach, creating up to 225 predictive maps for each mineral system. Up to 9 maps are included for the final models.

Left: Map of the central Lachlan Orogen Sn–W study area and Cobar Superbasin Cu–Au and Pb–Zn study areas showing the location of the mineral occurrences used to train the data-driven mineral potential models.
Right: Granite-related Sn–W mineral potential map for the central Lachlan Orogen.

Au mineral potential map (left) and Pb–Zn mineral potential map (right) for the Cobar Superbasin.

Related reports

  • FITZHERBERT J.A. & DOWNES P.M. 2020. A mineral system model for Cu–Au–Pb–Zn–Ag systems of the Cobar Basin, central Lachlan Orogen, New South Wales. Geological Survey of NSW.
  • BLEVIN P.L. 2020. A mineral system model for Palaeozoic granite-related Sn–W mineralisation in the central Lachlan Orogen, New South Wales. Geological Survey of NSW.
  • FORD A., PETERS K., DOWNES P., BLEVIN P., GREENFIELD J. & FITZHERBERT J. 2020. Central Lachlan Orogen mineral systems mineral potential report. Geological Survey of New South Wales.

Mineral potential data packages