Queensland Next Generation Mineral Mapping Project
The aim of the Queensland Next Generation Mineral Mapping Project (Cudahy et al., 2008) was to develop, validate, evaluate and deliver a suite of publicly available, pre-competitive mineral mapping products from airborne HyMap hyperspectral imagery and satellite multispectral ASTER imagery. Moreover, it was important to establish whether these mineral maps would complement other precompetitive geological and geophysical data and provide valuable new information for enhanced mineral exploration by the Australian resources community.
The project comprised several parts:
- Generating a suite of 15 mineral group maps of the Mount Isa Block (~500K km2) from satellite multispectral ASTER imagery (~140 scenes);
- Stage 1 (2006-2007): acquisition and generation of a suite of 22 mineral abundance and mineral composition maps derived from airborne HyMap hyperspectral imagery (88 flight-lines) covering five structural/mineralised corridors (each about 15 km wide and 50 km long and covering 8250 km2 ) across the Mount Isa Block; and
- Stage 2 (2007-2008): acquisition and generation of a suite of 29 mineral abundance and mineral composition maps derived from airborne HyMap hyperspectral imagery (204 flight-lines) covering four geological provinces (Mount Isa, Georgetown, Charters Towers and Hodgkinson) across geological/structural/mineralised corridors (each about 12 km wide and 50 km long and covering 16,000 km2) in north Queensland.
The image processing methodology used to generate the current suite of mineral mapping products was designed to process multiple flight-lines/images based on a physical model that does not rely on levelling but instead normalises most/all of the inherent complications typical of remote sensing data (i.e. topographic shading, surface directional scattering, solar illumination, residual atmospheric/instrument effects). Furthermore, this methodology aims to be transferable, i.e. applicable to other similar data, and easily implemented by others wanting to reproduce similar products. The mineral mapping processing methodology is based on the assumption that a given mineral abundance (or composition) is proportional to the normalised continuum-depth (wavelength, width, and asymmetry) of its diagnostic absorption bands, with zero abundance equal to no absorption developed. Currently, multiple masks are used to remove possible overlapping mineral absorptions and other effects like vegetation.
The HyMap-derived mineral maps can be downloaded from https://geoscience.data.qld.gov.au/ (enter “HyMap” into search and select “Spectral” from Data Types).
Figure: Selected mineral and geophysical maps of the Starra area showing attributes of granites that may provide a suitable fluid source for Cu-Au mineralisation (a) ferric iron mineral map; (b) white mica content mineral map; (c) magnetic susceptibility; and (d) radiometric ternary image. The dotted/dashed outlines of the Mount Dore granite (A) and the Gin Creek granites (B) are shown.
References:
Cudahy, T., Jones, M., Thomas, M., Laukamp, C., Caccetta, M., Hewson, R., Rodger, A., Verrall, M. (2008): Next Generation Mineral Mapping: Queensland airborne HyMap and satellite ASTER surveys 2006-2008.- CSIRO report P2007/364, 161pp. https://geoscience.data.qld.gov.au/data/report/cr133119
Laukamp, C., Cudahy, T., Thomas, M., Jones, M., Cleverley, J., Oliver, N. (2011): Hydrothermal mineral alteration patterns in the Mount Isa Inlier revealed by airborne hyperspectral data.- Australian Journal of Earth Sciences, 58 (8), 917-936.
Laukamp, C., Cudahy, T., Cleverley, J., Oliver, N., Hewson, R. (2011): Airborne hyperspectral imaging of hydrothermal alteration zones in granitoids of the Eastern Fold Belt (Mount Isa Inlier, Australia).- Geochemistry: Exploration, Environment, Analysis. 11: 3-24.
Murphy, F.C., Kendrick, M.A., Aillères, L., Jupp, B., McLellan, J., Rubenach, M.J., Laukamp, C., Oliver, N.H.S., Roy, I.G., Gessner, K., Bierlein, F.P., Walshe, J.L., Cleverley, J.S., Hutton, L.J. (2011): Mineral system analysis of the Mt Isa–McArthur River region, Northern Australia.- Australian Journal of Earth Sciences, 58 (8).