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Australian release of high resolution satellite ASTER imagery helps hunt for mineral resources

on May 2, 2012 Library

Geological use of high-resolution satellite ASTER geoscience maps may help in the hunt for mineral resources in South Australia.

ASTER (an acronym for Advanced Spaceborne Thermal Emission and Reflection Radiometer) is a Japanese sensor which is one of five remote sensory devices on board the Terra satellite launched by NASA in 1999, since which time data collection has been ongoing. The latest ASTER geoscience imagery was released by the South Australian government and is available free to explorers.

The new release is a co-operative effort between the Centre of Excellence for 3D Mineral Mapping, the Minerals Down Under flagship of CSIRO, Geoscience Australia, NASA, and the Japanese government.

The web-accessible ASTER geoscience map of SA is a set of digital geoscience products generated from satellite ASTER data. It’s made possible by advances in collecting and processing information from satellites using the latest in remote-sensing imaging capabilities after the older Landsat Thematic Mapper. ASTER technology captures high spatial resolution data in 14 bands, from the visible to the thermal infrared wavelengths, and provides stereo viewing capability for digital elevation model creation.

The end result is a level of accuracy and detail never before seen in South Australia, says Dr. Tim Baker, director of the state’s Geological Survey.

Baker told the Adelaide Now newspaper that "ASTER maps provide a Google-like ‘mineral zoom’ of the cover overlying geological formations, aiding explorers in the search for economic mineral deposits.

“This processing technology means explorers can now see spectral wavelengths sensitive to important rock-forming minerals including iron oxides, clays, carbonates, quartz, and alteration minerals such as muscovite and chlorite,” he said.

The information gleaned will both help exploration companies plan their drilling programs and complement the state’s archive of drill core data. More specifically, the information will aid in the accurate mapping of the regolith cover that blankets much of Australia. As a result, those often small islands of bedrock materials will be easier to locate.

ASTER shortwave infrared bands are especially useful in mapping clastic and carbonate stratigraphy and volcanic environments and are also effective in predicting mineral groups and specific minerals such as kaolinite, alunite, illite, muscovite, montmorillonite, chlorite, calcite, dolomite and serpentine.

The ASTER map of South Australian is the second installment of an Australian ASTER geoscience map that is being developed in co-operation with the other State and Territory surveys and Geoscience Australia. A national map is scheduled for release at the 34th International Geological Congress in Brisbane in August, 2012. Both maps are being generated through Western Australia’s Centre of Excellence for 3D Mineral Mapping. Later updates of this map may include improved removal of complicating vegetation effects and products derived from thermal infrared.

Explorers can view the ASTER maps on SARIG 2020, the South Australian Resource information Geoserver. Go to www.sarig.dmitre.sa.gov.au and select the regional mineral map tab. Google chrome is the recommended browser.

Sources: adelaidenow.com.au, myresources.com.au and csiro.au