geological mapping and mineral exploration

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HyVista Corporation

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  • HYVISTA CORPORATION

    AIRBORNE HYPERSPECTRAL REMOTE SENSING

    GEOLOGICAL MAPPING and

    MINERAL EXPLORATION

  • Why use HyVista for your next airborne remote sensing survey? With over a decade of experience and the bene-fits of continual product development, HyVista uses the HyMap sensor to provide the worlds best hyperspectral imagery. We are committed to delivering the maximum outcome for our clients.

    HyVista Delivers Every Time

    SUPERIOR SENSORS :: SUPERIOR SERVICE :: SUPERIOR PRODUCTS This is not our mission statement; this is our promise

    HyVista Corporation Pty Ltd The company specialises in the supply of airborne hyper-spectral remote sensing imagery and information products for a wide range of applications including geological mapping, mineral exploration, environmental monitoring, agriculture and land use planning. The company also provides imagery to support R&D projects in areas of future satellite simulation, defence surveillance, soil degradation and vegetation species mapping. Hyperspectral remote sensing (or spectral imaging)provides a significant advantage over the more traditional multi-spectral imaging by leveraging the power of spectroscopy to make more detailed discrimination and identification of the earths surface materials and to be able, in many cases, to reveal details of the materials physical and chemical state. For more than a decade, the company has been delivering survey products of the highest quality to its clients and continues to maintain a high level of product development, from equipment performance through to the most effective image processing outcomes. The companys mission is to provide our clients with a world best survey service and product delivery on a worldwide basis.

  • Application in Geological Mapping and Mineral Exploration

    Mineral Spectral Signatures: Effect of Spectral Resolution

    Spectra recorded by the HyMap scanners show the same diagnostic informa-

    tion as those measured in the laboratory by the USGS. In comparison ASTER

    spectra are under-sampled and critical diagnostic information can be lost.

    Mineral Spectral Signatures: Seamless Maps

    The seamless mineral map (above) was produced from 27 strips of HyMap

    imagery acquired in Namibia during 2005. The image is a grayscale background

    overlain with the distribution of the 9 minerals derived from the HyMap data

    at a spatial resolution of 5m.

    High resolution spectral sensing (hyperspectral) is an advanced remote sensing technique that maps the

    distribution of surface materials through their spectral signatures. This technology can be applied to

    applications in mineral exploration, geological mapping and environmental monitoring.

    The successful application of this technique depends on having sensors with high signal to noise ratio

    and sufficient spatial and spectral resolution. HyVista Corporation utilises the HyMap airborne

    hyperspectral sensor which delivers world best performance.

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  • MtWhalebackisanironoremineintheOpthalmiaRange

    andisprobablytherichestdepositinthegreatHamersley

    IronProvincewhichstartsatthecoastnorthofOnslow

    andrunsESEformorethan500km.

    Theprovincecontainsvastquantitiesofironbearing

    material,anestimated24,000milliontonnesat55%iron.

    TheMtNewmandepositsareinamineralleasecovering

    nearly800squarekm.

    MtWhalebackistheprimeorebody(5.5kmlongand

    225mhigh)andliesintheNewmanareaoftheleaseat

    theeasternedgeoftheOpthalmiaRangeandisassayedat

    68.8%ironcontent(withapossiblemaximumof70%

    pureiron).

    AHyMapdemonstrationtestsurveywasflownonthe

    25thOctober2007.

    MAPPINGHEMATITE,GEOTHITEANDSURROUNDINGLITHOLOGIESFROMHYMAP

    HYPERSPECTRALIMAGERYINTHEMOUNTWHALEBACKIRONOREMININGAREA

    LOCATION DIAGRAM

    Mt Whaleback

    Western Australia

    IRONOREMINERALMAPPINGairbornehyperspectralremotesensing

  • [email protected]>85%probabilityofoccurrence

    >85% >99%

    LeftTop:

    HematiteandgoethitespectraextractedfromtheJPLspectrallibrary

    (overtherange0.7to1.0micronsVNIRregion)thathavebeen

    convolvedtothewavelengthchannelsoftheHyMapscannerusedforthis

    survey.Noteshiftinpeakat~0.7micronsandtroughat>0.8micronsto

    longerwavelengthsingoethitecomparedtohematite.

    [email protected]>85%probabilityofoccurrence

    MOREINFORMATIONFormoreinformationonHyMapsurveysformineralexplorationorenvironmentalassessmentpleasecontact:

    HyVistaCorporationPtyLtdphone:+61288500262email:[email protected]

    LeftBottom:

    Hematiteandgoethitespectraobtainedfromthesurveydata.

    Afterflightstripdatahasbeenconvertedtoreflectance,BRDF

    correctedandmosaicked,processinghasbeenappliedtomapthe

    distributionofhematite,goethiteandbackgroundmineralsincluding

    kaolinite,muscoviteandchlorite.

    Thereareseveralwaysinwhichthemineralmappingdatacanbe

    presentedasshownintheimagesbelow.

    MineralMapClassification

  • Kimberlite Mineralogy and Weathering Products

    MINERAL MAPPING IN KIMBERLITE EXPLORATION

    Hyperspectral surveys, can be used in diamond exploration to

    locate kimberlites that are exposed or weathered in areas of

    residual soil.

    Transported overburden, masking rock formations and vegetation

    cover exceeding 70% preclude surveys. Surveys need to be

    conducted during the dry season. Presence of other ultramafic

    rocks and amphibolites produce similar spectral targets but

    analysis by experienced spectral geologists and advanced data

    processing reduces the number of non-kimberlite anomalies.

    DIAMOND EXPLORATION

    The original HyMap scanner was commissioned by De Beers for kimberlite

    discovery. Over 25 kimberlites (both pipes and dykes) were discovered

    between 1997 and 2005, at a relatively low cost compared to other

    methodologies. Most exceeded 1 hectare and required minimal follow-up

    for confirmation. In suitable areas, hyperspectral surveys are a cost-

    effective kimberlite exploration technique, comparable in price to high-

    resolution aeromagnetic surveys but with significantly lower follow-up

    costs. The ratio of targets to kimberlite discovery is similar to that of

    aeromagnetic surveys and is dependent on the geological conditions

    within the survey area.

    Left: True colour

    composite of Pine

    Creek kimberlite field

    in South Australia.

    Yellow boundaries are

    confirmed kimberlites;

    green boundaries are

    probable kimberlites

    and the blue boundary

    is a buried kimberlite.

    Right: Index image

    created from spec-

    trally classified images

    (far left, 4 & 5). Blue

    overlay maps distribu-

    tion of Mg-Carbonate

    and red overlay

    occurrence of

    Mg-Smectite. Not all

    of the red anomalies

    have been field

    checked.

    Wavelength nm

    1300 1500 1700 1900 2100 2300 2500

    Pine Creek, South Australia

    Data Processing

    The Mg rich unweathered minerals in kimberlinte (above) progressively alter during weathering

    into minerals that have distinct spectral signatures (red boxes) which can be detected in hyper-

    spectral data. Those highlighted in dashed boxes are not typically observed in residual regolith

    derived from kimberlite, though they may be apparent in outcropping kimberlite. The spectral

    signature of these minerals, apart from hematite and silica, are characterised by a strong ab-

    sorption minima at ~2300nm and ~2390nm (right). Though not unique to kimberlite detection,

    anomalous occurrences of these minerals can lead to the discovery of kimberlite, particularly

    when combined with other exploration data in GIS analysis. Neither hematite nor silica can be

    used effectively to locate kimberlite.

    To detect mineral anomalies indicative of kimberlite, the hyperspectral image (1 below) is proc-

    essed so that new bands are derived showing the distribution of spectrally distinct materials (2

    & 3). The band (4) that maps the target spectrum (2) is then selected and further processed to

    highlight anomalous occurrences of the target being sought. The spectra of the anomalous

    regions of interest are then checked and those requiring follow-up selected.

    airborne hyperspectral remote sensing

  • Above Right: Natural Colour HyMap Image

    Above Left: RGB Talc-Saponite, Nontronite and Serpentine supervised spectral classification image mineral map

    (same area as CC). Kimberlite is bright feature in centre, >6 hectares.

    Index image showing distribution of Mg-OH minerals, carbonates and kaolinite in

    red, green and blue. The kimberlite dyke crosses the centre of the image and is

    highlighted in red due to its high Mg-OH mineral content. Other red areas indicate

    amphibolite and greenstones.

    Results from kimberlite

    mapping in the survey sub

    area. Known and discovered

    kimberlites shown in red; those

    located from hyperspectral

    imagery shown with circles.

    Right:

    Simplified geological map of

    HyMap survey area in West

    Greenland.

    Survey area indicated by

    black