Base Metal Potential – Amadeus Basin, NT

Mineral exploration in remote underexplored sedimentary basins is often hindered by the lack of understanding basin architecture and host-rock potential. In this project we provided an improved 3D framework for mineral exploration.

The Amadeus Basin is mostly known for its hydrocarbon resource, but regarded as prospective for sediment-hosted Cu, Pb, Zn. However, mineral exploration is hindered by poor understanding of the mineral system.

The project (2012-2015) aimed to assess the mineral and hydrocarbon potential by applying and bringing together new technologies and mineral systems thinking from petroleum and mineral exploration. For example, basin inversion modelling using gravity and magnetic data helped to construct a 3D architecture in combination of seismic and shallow magnetic interpretation of stratigraphic packages. The basin fluid and temperature history were interpreted from fluid inclusion thermometry in combination with petrographic investigations. The redox potential of each stratigraphic unit was assessed by a combination of mineralogical, geochemical and isotopic studies. We also reprocessed spectral ASTER data towards known lithologies and improved mapping of stratigraphic units.

The assessment revealed a pre-Amadeus Basin rift sequence composed of mafic igneous rocks that could be metal source, and identified various stratigraphic units that could be source of host of sediment-hosted mineral deposits. The hydrogeochemistry, diagenetic studies and fluid inclusion thermometry in combination with the structural architecture showed basin fluids have ideal conditions for transporting and concentrating metals along the basin margin.

amadeus

Publications/reports:

Schmid, S., Smith, P.M., Woltering, M., 2018. A basin-wide record of the Late Cambrian Steptoean positive carbon isotope excursion (SPICE) in the Amadeus Basin, Australia. Palaeogeography, Palaeoclimatology, Palaeoecology, 508, 116-128.

Schmid, S., Kunzmann, M., Pages, A., 2017. Inorganic geochemical evaluation of hydrocarbon source rock potential of Neoproterozoic strata in the Amadeus Basin, Australia. Marine and Petroleum Geology, 86, 1092-1105.

Austin, J.R., Schmid, S., Foss, C.A., 2017. Using stratiform magnetic anomalies to map near-surface architecture: insights from the Amadeus Basin. Australian Journal of Earth Sciences, 64, 3, 353-383.

Schmid, S., 2017. Chemostratigraphy and palaeo-environmental characterization of the Cambrian stratigraphy in the Amadeus Basin, Australia. Chemical Geology 451, 169-182.

Schmid, S., 2017. Neoproterozoic evaporites and their role in carbon isotope chemostratigraphy (Amadeus Basin, Australia). Precambrian Research 290, 16-31.

Schmid, S., Schaubs, P., Austin, J., Foss, C., Gray, D., Laukamp, C., Kempton, R., Bourdet, J., Trefry, C., leGras, M., 2016. COBRA – Amadeus Basin – Assessment of Resource Potential, (CSIRO EP157036) NTGS Record DIP16, 478pp.

Foss, C., Austin, J.R., Schmid, S., 2015. COBRA – Amadeus Basin Project: Gravity and Magnetic study of the Western Amadeus Basin, Western Australia. Geological Survey of Western Australia, Report 154. 49pp.