Spectral Geology Lecture series presented by the UWA
Spectral Geology Lecture series presented by the UWA Student Chapter of the by the Lecture series presented UWAof. Student Chapter Society Economic Geologists of the Society of Economic Geologists 2 June 2009
Objective To show remote (airborne and satellite imagery) and field/drill-core (e. g. ASD™, micro. FTIR™ and Hylogger™) spectral data can be applied for exploration and research. • Asking the right questions! • Mineral system analysis • Integration with geophysical and geochemical data
Outline 9: 00 - 9: 15: Introduction to spectral geology and the available technologies - Carsten Laukamp (CET) 9: 15 - 10: 00: Is spectral geology complementary to current geophysics? - Rob Hewson (CSIRO) 10: 00 - 10: 20: The application of ASTER and ASD data at Pataz Goldfields, Northern Peru - Wally Witt (CET) 10: 20 - 10: 35: Coffee break 10: 35 - 11: 20: Mine scale spectral geology - Ore characterisation using "Hy. Logging Systems” - Erick Ramanaidou (CSIRO) 11: 20 - 12: 05: 3 D spectral geology - mineral systems, exploration targeting and C 3 DMM - Tom Cudahy (CSIRO) 12: 05 - 12: 30: Qand. A - led by SEG Student Chapter and Carsten Laukamp
Mineral Mapping Theory
Mineral Mapping Theory
Mineral Mapping Theory
Mineral Mapping Theory • Diagnostic absorption features of hydroxyl mineral groups in the SWIR – Al(OH): 2170 - 2210 nm • Topaz, Pyrophyllite, Kaolinite, Montmorillonite, Muscovite, Illite – “Mg(OH)”: 2300 - 2400 nm • Chlorite, Talc, Epidote, Amphibole, Antigorite, Biotite, Phlogopite – “Fe(OH)”: 2250 - 2300 nm • Jarosite, Nontronite, Saponite, Hectorite – Si(OH): 2240 nm (broad) • Opaline silica
Composition of Minerals • white mica composition • crystallinity of white micas or clay minerals • Mg# of chlorites • carbonate composition • … mineralminers. com/html/musmins. stm (Mg, Fe)oct Sitet = Aloct Al tet interlayer K, Na, Ca tetrahedral Si, Al octahedral Muscovite Al, Fe, Mg, Cr, V Phengite From Scott and Yang, 1997
Spectral-Mineral Wavelength Regions iron oxides REEs vegetation Visible Near VNIRInfrared OH-bearing hydroxyls (kaolin, chlorite, mica, amphibole) sulphates carbonates Non-OH-bearing silicates Spectral Resolution (quartz, feldspars, pyroxene, garnet) sulphates carbonates Short Wave Infrared SWIR Thermal Infrared Laboratory ARGUS / AVIRIS HYMAP ASTER Landsat TM From Peter Hausknecht
Available Technologies (examples) • Field spectral devices: • PIMA • Fieldspec Pro • TERRASPEC • micro. FTIR • Hylogger system: • Hy. Logger™ • Hy. Chips™ • TIR-Logger™ • Remote sensing devices: • airborne (e. g. Hy. Map) • satellite (e. g. ASTER)
Field Spectral Devices • Anayltical spectral devices (ASD, http: //www. asdi. com) • Fieldspec Pro • 350 -2500 nm • 10 nm spectral resolution @ SWIR • ~AUD$100 K • TERRASPEC • More robust fibre • contact Fieldspec Pro Integrated Spectronics (ISPL, http: //www. intspec. com) • PIMA (Portable Infrared Mineral Analyser) • 1300 -2500 nm • 8 nm resolution • contact • ~AUD$40 K TERRASPEC
Hylogging Suite • Hy. Logger™ • • 0. 4 -2. 5 m FTIR (D&P) diamond drill core logging ~700 m / day • 1 cm line-profile footprint • Hy. Chips™ • • 0. 4 -2. 5 m ASD based RAB/RC drill chip tray logging 45 trays / hour (up to 3000 * 1 m samples p/d) • TIR-Logger™ • • • 2. 5 -20 m FTIR (D&P) Diamond drill (and Chips) ~700 m / day 1 cm line-profile footprint
Remote Sensing Spectral Devices
Airborne Hy. Map www. hyvista. com • • • Australian sensor Sydney-based NASA-approved high SNR 126 bands 0. 4 -2. 5 m 3 -30 m pixel 512 pixel swath whiskbroom fully calibrated Spectral Configuration – 128 channels Module Spectral range Bandwidth Average spectral across module sampling interval VIS 0. 45 – 0. 89 um 15 – 16 nm 15 nm NIR 0. 89 – 1. 35 um 15 – 16 nm 15 nm SWIR 1 1. 40 – 1. 80 um 15 – 16 nm 13 nm SWIR 2 1. 95 – 2. 48 um 18 – 20 nm 17 nm
Airborne Hy. Map white mica composition false colour Hy. Map products delivered for the Qld Next Generation Mineral Mapping Project (excerpt) (http: //www. em. csiro. au/NGMM/): • • • • • • Natural colour basemap; False colour basemap; Green vegetation content; Dry vegetation content; Iron oxide content; Hematite/Goethite ratio; Ferrous iron content; Kaolin crystallinity; Al-smectite content; Al-smectite composition; White mica (paragonite-muscovite-phengite) content; White mica composition; White mica crystallinity; Mg. OH (cc/dol/chl/ep/amph) content; Mg. OH (cc/dol/chl/ep/amph) composition; Ferric iron and Mg. OH; Ferrous iron and Mg. OH; Chlorite-Epidote content; Opaques; Hydrated silica Block H 5 km 2190 nm Al-rich 2215 Al-poor nm
ASTER (Advanced Spaceborne Thermal Emission and Reflective Radiometer) • “Next generation” geology-tuned satellite sensor: • 14 spectral bands including 6 SWIR and 5 TIR geological bands (+ DEM) • 15 m VNIR • 30 m SWIR • 90 m TIR • Pushbroom for VNIR and SWIR • Whiskbroom for TIR • Significant Instrument/Data Issues • atmospheric correction, SWIR X-talk, TES www. asterweb. jpl. nasa. gov www. science. aster. ersdac. or. jp
Software • TSG (the Spectral Geologist) – Field and core spectra • TSA (the Spectral Assistant) • TSG-Core Distributed through Ausspec (www. ausspec. com) • ENVI (Environment for Visualising Images) (www. ittvis. com) – Hyperspectral images – Field spectra • ERMapper (www. ermapper. com) – ASTER wizard • CSIRO/Hy. Vista Suite – ASTER and hyperspectral multi-scene processing • C-Hyper. MAP • C-Sat. MAP – IDL based
Outline 9: 00 - 9: 15: Introduction to spectral geology and the available technologies - Carsten Laukamp (CET) 9: 15 - 10: 00: Is spectral geology complementary to current geophysics? - Rob Hewson (CSIRO) 10: 00 - 10: 20: The application of ASTER and ASD data at Pataz Goldfields, Northern Peru - Wally Witt (CET) 10: 20 - 10: 35: Coffee break 10: 35 - 11: 20: Mine scale spectral geology - Ore characterisation using "Hy. Logging Systems” - Erick Ramanaidou (CSIRO) 11: 20 - 12: 05: 3 D spectral geology - mineral systems, exploration targeting and C 3 DMM - Tom Cudahy (CSIRO) 12: 05 - 12: 30: Qand. A - led by SEG Student Chapter and Carsten Laukamp
- Slides: 18