Spectral Geology
West Pilbara Hyperspectral gold exploration case-study
Airborne
HyMap hyperspectral data was used to map mineral assemblages associated
with gold deposits. A previously unknown gold zone was immediately found
by association with pyrophyllite detected by hyperspectral imaging..
Read More: Bierwirth, P.N., Blewett, R and Huston,D (1999). Finding new mineral prospects with HYMAP: early results from an hyperspectral remote sensing case study in the West Pilbara. AGSO Research Newsletter, No 31, November 1999
Bierwirth, P.N., Blewett, R and Huston,D., (2002). Hyperspectral mapping of mineral assemblages associated with gold mineralization in the West Pilbara, W.A. Economic Geology, vol 97, no 4, p819-826.
Laboratory and imaging spectroscopy of tourmaline group minerals- a tool for mineral exploration
This
is a study of the spectral features of tourmaline group minerals in the
VNIR to SWIR wavelength range. Tourmaline is a hydrothermal mineral that
is important as an indicator for gold and metals exploration. The spectroscopy
is complex and for natural materials, there may be no rivals in terms
of the number of narrow spectral features across the VNIR-SWIR range.
Analysis of hyperspectral imagery in the Pilbara region, W.A., demonstrates
that rapid spectral identification of tourmaline be used to determine
proximity to ore-bodies and hence is a valuable exploration tool.
Read More: Bierwirth, P.N., (2008). Laboratory and imaging spectroscopy of tourmaline - a tool for mineral exploration. 14th Australasian Remote Sensing and Photogrammetry Conference, Darwin (Paper) (Presentation)
Evaluation of ASTER satellite data for geological applications
The ASTER satellite sensor,
at medium spectral resolution, poses a challenge for the analyst. In this study, ASTER analysis results were
presented for areas at Laverton. W.A. and in the Pilbara, W.A. the latter being compared with airborne
hyperspectral data and field data. For the Pilbara study, ASTER was partially successful in mapping carbonate,
Fe-chlorite, white-mica, kaolinite, tourmaline, talc and Fe-oxides. The analysis did not work for pyrophyllite.
In the Laverton area, ASTER rock-type end-members shows the subtle change in rock units between acid, intermediate to
basic igneous units, information that is not represented on the geological map. Thermal IR data were found to be
valuable, particularly in the Laverton area, for mapping quartz rich units and the dispersion of associated
sandy soils.