Hyperspectral mapping of an Ancient Hydrothermal System

1
Hyperspectral mapping of an Ancient Hydrothermal
System at the North Pole Dome, Pilbara
Craton, Western Australia
AND APPLICATIONS FOR MARS
2
Astrobiology

• To study all aspects of life, particularly its
• Origins
• Habitats
• Future

3
(No Transcript)
4
Satellite or aeroplane
reflectance
wavelength
Critical to concentrate on correct vibration
regions!
5

• Muscovite KAl2(Si3Al)O10(OH)2
• produced when feldspar is broken down by water
• common proximal hydrothermal mineral
• Not easily destroyed once formed
• Vibrations active in 2-2.5 micron region
• Possible geothermometer

6
MAPPING TEMPERATURE ZONES AT A VOLCANIC VENT
200m
(Microns)
Short wavelength
Long wavelength
7
Results Dresser Formation
N
8
Chlorite
Muscovite
Serpentine
3km
Kaolinite
N
9
N
3km
10
Stromatolite occurrences?
3km
N
11
THEMIS Instrument

• In operation on Mars Odyssey since 2001
• Coverage in VIS and IR
• 3.6km wide swathes, variable length
• Bands
• 5 bands VIS 0.3-0.6 microns 19m resolution
• 10 bands IR 6.5-14.5 microns 100m resolution
• Problems
• Cross-band correlation
• Band 5 VIS U/S
• Band 12 IR duplicated
• Band 10 IR CO2 masked
• Coverage not always multispectral

12
Spirit Landing Site Gusev Crater
30km
13
How to catch a Martian

• What do the results of this project suggest?
• Look in the right part of the spectrum
• Concentrate on hydroxyl to find alteration
• Use muscovite as indicator and geothermometer
• Automate discovery of absorption
• Use newly developed Gaussian deconvolution

14
Remaining work

• Refine Pilbara mineral maps using ground truthing
  data
• Investigate causes of high and low temperature
  micas and correlate with possible vent sites
• Investigate other sites on Mars using THEMIS
• Write up for completion in November 2005

15
Acknowledgements

• Special thanks to
• Fieldwork assistance from Geological Survey of
  Western Australia (Dr. Martin Van Kranendonk and
  Dr. Kath Grey)
• Ground-truth assistance from GEMOC Geochemical
  Analysis Unit (Dr. Norm Pearson, Carol Lawson,
  Peter Wieland and Tin Tin Win).
• Hot Tips from Prof. Dick Flood

16
QUESTIONS? WEBSITE! http//aca.mq.edu.au/abrown.ht
m