Hyperspectral project

Hyperspectral surveys use visible to infrared radiation from the earth's surface to identify surficial distribution of various minerals.  The hyperspectral instrument is a passive system that records reflected sunlight as the aircraft flies over the survey area.  The data can be processed to map the distribution of selected minerals on the land surface, as well as providing natural and false colour high resolution images.  Vegetation, dust and pollution can also be mapped from hyperspectral datasets.

Hyperspectral surveys enable rapid, no impact data collection complementing satellite imagery, aerial photography, magnetics, radiometrics and gravity surveys.  The resulting mineral maps are of great assistance to mineral explorers by identifying areas of alteration and enabling mineral emplacement models to be tested.

The surface minerals have direct relevance to mineral exploration by helping identify areas of mineralisation, or areas of chemical alteration that may characterise sub-surface deposits at mineable depths.

Airborne hyperspectral surveys are one of the new high technology airborne geophysical methodologies being applied to mineral exploration. 

Funding was derived from the Queensland Smart Exploration program in 2006 for the stage 1 survey, and from the Smart Mining - Future Prosperity program in 2007 for the Stage 2 survey.

The Stage 1 survey acquired airborne hyperspectral data over parts of the highly prospective Mount Isa base metals province, whilst Stage 2 will investigate additional areas at Mount Isa as well as other prospective regions including Croydon-Kidston, the Hodgkinson Basin, and the Pajingo area south of Charters Towers.

All of these areas were specifically chosen to target prospective mineralised regions, major faults, and transects to cover a range of geology and mineralisation types.

Stage 1

The Stage 1 hyperspectral survey consists of 15km wide swaths at 5m resolution over areas with significant known deposits, eg Mount Isa - Cu, Pb, Zn; Century - Zn; Cannington - Zn, Ag; Lady Loretta - Zn; Dugald River - Pb, Zn; Tick Hill - Au; Cloncurry - Cu, Au; Selwyn - Cu; and Mary Kathleen - U, and covered a total length of approximately 570km and a total area of approximately 8250km².

• Termite Range - extends along Termite Range Fault south-east from Century
• Lady Loretta-Dugald River (along proposed Seismic Line)
• Pilgrim - extends along major faults from Tick Hill to Dugald River
• Selwyn - extensively mineralised area
• Cloncurry - along Cloncurry Fault

Stage 2

Survey Details - Stage 2

Areas to be flown include 15km-wide swaths at 5m resolution, with a total length of approximately 1117km and a total area of approximately 16 750km². Stage 2 will be flown in July-August 2007 and the outcomes will be released in June 2008.

Products

CSIRO delivered the Stage 1 results on time in early July 2007, comprising the basic data  and 22 GIS compatible maps.  The products are available for web download from the CSIRO web site (free download).

Alternatively, the (voluminous - >350GB) basic data is available on an external hard disk drive for the 'cost of provision' (contact geophysics@dme.qld.gov.au), and a DVD of the derived products is also available for 'cost of provision' (contact sales@dme.qld.gov.au).

The products from the Stage 1 phase are designed to meet a range of user needs. 

• Basic raw data is available for users with access to appropriate software and expertise in data processing; the total volume of data is about 350Gb.  The data comprise both radiance and reflectance data for each flight line; the lines are not mosaiced into the full 15km swath widths to keep file sizes manageable.  Users will need to apply their own atmospheric corrections, and process the data to prepare mineral maps.
• Basic raw data can also be provided to research groups, educational institutions, or third party service providers to process the data to a user's requirements.
• 22 map products prepared by CSIRO are available in jpeg2000 and ECW formats.  The images are readily loaded into GIS software such as ArcMap and MapInfo.  Free plugins are available for versions that require them.  These data can be related to other information in the GIS environment such as mineral occurrences, tenement boundaries, geology and geophysics.  Hyperspectral data can assist explorers to evaluate their mineral deposit models within their areas of interest.

Participants

Geological Survey of Queensland, CSIRO, HyVista Corporation, Geoscience Australia, James Cook University

For more information contact:

Mal Jones

Telephone: +61 7 3362 9348

or the Geological Information Hotline
at +61 7 3006 4666 (9.00am to 4.00pm EST workdays)

or go to the CSIRO web site.