A multi-agency collaboration between Australian government partners has been working towards making continent-scale, public, web-accessible and GIS-compatible ASTER geoscience maps. CSIRO along with Geoscience Australia and several state government agencies, (including GSWA, GSQ, DMITRE and NTGS), have developed methodology and produced 15 geoscientific products, with applications for mineral mapping and exploration, soil-mapping, environment and agricultural sectors. This work represents the largest ASTER mosaic of this type in the world and sets a new benchmark for state-to-continent scale spectral remote sensing. The project is supported both nationally and internationally by the ASTER Science Team, ERSDAC, NASA and the USGS. Outcomes include the formation of a platform for establishing national standards; geoscience product nomenclature; processing methods; accuracy assessments; and traceable documentation. Detailed product notes outline these standards and provide significant knowledge transfer for existing and new users of this type of data. Hyperion satellite hyperspectral imagery has been critical for calibration and validation of the processed ASTER data, reduction to 'surface' reflectance using independent validation data such as Hyperion, and calculating statistics to generate regression coefficients, reduces errors in the ASTER instrument and increases reliability and corroboration of spectral responses.

1. Band ratio: B5/B4 Blue is low abundance, Red is high abundance This product can help map exposed "fresh" (un-oxidised) rocks (warm colours) especially mafic and ultramafic lithologies rich in ferrous silicates (e.g. actinolite, chlorite) and/or ferrous carbonates (e.g. ferroan dolomite, ankerite, siderite). Applying an MgOH Group content mask to this product helps to isolate ferrous bearing non-OH bearing minerals like pyroxenes (e.g. jadeite) from OH-bearing or carbonate-bearing ferrous minerals like actinolite or ankerite, respectively. Also combine with the FeOH Group content product to find evidence for ferrous-bearing chlorite (e.g. chamosite).

1. Band ratio: (B10+B12)/B11 Blue is low gypsum content. Red is high gypsum content. Accuracy: Very Low: Strongly complicated by dry vegetation and often inversely correlated with quartz-rich materials. Affected by discontinuous line-striping. Use in combination with FeOH product which is also sensitive to gypsum. Geoscience Applications: Useful for mapping: (1) evaporative environments (e.g. salt lakes) and associated arid aeolian systems (e.g. dunes); (2) acid waters (e.g. from oxidising sulphides) invading carbonate rich materials including around mine environments; and (3) hydrothermal (e.g. volcanic) systems.

1. Band ratio: B1/B4 Blue is low abundance, Red is high abundance (potentially includes carbon black (e.g. ash), magnetite, Mn oxides, and sulphides in unoxidised envornments Useful for mapping: (1) magnetite-bearing rocks (e.g. BIF); (2) maghemite gravels; (3) manganese oxides; (4) graphitic shales. Note 1: (1) and (4) above can be evidence for "reduced" rocks when interpreting REDOX gradients. Combine with AlOH group Content (high values) and Composition (high values) products, to find evidence for any invading "oxidised" hydrothermal fluids which may have interacted with reduced rocks evident in the Opaques index product.

B6/B5 (potential includes: pyrophyllite, alunite, well-ordered kaolinite) Blue is low content, Red is high content Useful for mapping: (1) different clay-type stratigraphic horizons; (2) lithology-overprinting hydrothermal alteration, e.g. high sulphidation, "advanced argillic" alteration comprising pyrophyllite, alunite, kaolinite/dickite; and (3) well-ordered kaolinite (warmer colours) versus poorly-ordered kaolinite (cooler colours) which can be used for mapping in situ versus transported materials, respectively.

1. Band ratio: B4/B3 Blue is low abundance, Red is high abundance (1) Exposed iron ore (hematite-goethite). Use in combination with the "Opaques index" to help separate/map dark (a) surface lags (e.g. maghemite gravels) which can be misidentified in visible and false colour imagery; and (b) magnetite in BIF and/or bedded iron ore; and (3) Acid conditions: combine with FeOH Group content to help map jarosite which will have high values in both products. Mapping hematite versus goethite mapping is NOT easily achieved as ASTER's spectral bands were not designed to capture diagnostic iron oxide spectral behaviour. However, some information on visible colour relating in part to differences in hematite and/or goethite content can be obtained using a ratio of B2/B1 especially when this is masked using a B4/B3 to locate those pixels with sufficient iro oxide content.

1. Band ratio: B5/B4 Blue is low ferrous iron content in carbonate and MgOH minerals like talc and tremolite. Red is high ferrous iron content in carbonate and MgOH minerals like chlorite and actinolite. Useful for mapping: (1) un-oxidised "parent rocks" - i.e. mapping exposed parent rock materials (warm colours) in transported cover; (2) talc/tremolite (Mg-rich - cool colours) versus actinolite (Fe-rich - warm colours); (3) ferrous-bearing carbonates (warm colours) potentially associated with metasomatic "alteration"; (4) calcite/dolomite which are ferrous iron-poor (cool colours); and (5) epidote, which is ferrous iron poor (cool colours) - in combination with FeOH content product (high).

1. Band ratio: B2/B1 Blue-cyan is goethite rich, Green is hematite-goethite, Red-yellow is hematite-rich (1) Mapping transported materials (including palaeochannels) characterised by hematite (relative to geothite). Combine with AlOH composition to find co-located areas of hematite and poorly ordered kaolin to map transported materials; and (2) hematite-rish areas in drier conditions (eg above the water table) whereas goethite-rich in wetter conditions (eg at/below the water or areas recently exposed). May also be climate driven.

1. Band ratio: (B6+B9/(B7+B8) Blue is low content, Red is high content (potentially includes: calcite, dolomite, magnesite, chlorite, epidote, amphibole, talc, serpentine) Useful for mapping: (1) "hydrated" ferromagnesian rocks rich in OH-bearing tri-octahedral silicates like actinolite, serpentine, chlorite and talc; (2) carbonate-rich rocks, including shelf (palaeo-reef) and valley carbonates(calcretes, dolocretes and magnecretes); and (3) lithology-overprinting hydrothermal alteration, e.g. "propyllitic alteration" comprising chlorite, amphibole and carbonate. The nature (composition) of the silicate or carbonate mineral can be further assessed using the MgOH composition product.

Comprises a national satellite imagery mosaic and derived information products produced by a collaboration of CSIRO, Geoscience Australia (GA) and State and Territory Surveys, and several additional national and international collaborators. Mineral products were derived using a validated mosaic of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. <b>Value: </b>The data are used to understand distributions of and changes in surface materials and assessment of environmental, agricultural and resource potential. <b>Scope: </b>This dataset covers the continent with the intent to provide the best quality mosaic from 10+ year archive of scenes across Australia (i.e., lowest cloud/vegetation cover, high sun angle etc)