1. Application of TES Spectral Data to Rock Varnish
Taylor Feiereisel
Mentors: Shawn Wright
Laurie Rogers

2. Overview:
Orbital TES thermal infrared (TIR) spectral data concludes two different types of rock surfaces on Mars in the low albedo regions of Mars
Surface Type I (STI) = Basalt
Surface Type II (STII) = ???
Clay-manganiferous rock coatings called desert varnish could manipulate the TES TIR STII spectral data.
Approach: Laboratory Spectroscopy
Results and Implications
Acknowledgements

3. Mars TIR History:
Mars Global Surveyor
Mars Odyssey 2001
THEMIS
TES

4. STI and STII Sites Northern Hemisphere Southern Hemisphere
Sources: Wyatt and McSween, 2002; Hamilton et al., 2003
Southern Hemisphere

5. Rock Coatings:
Rock Coatings are additional sub aerial layers on a rock derived through multiple biochemical and geomorphologic processes.
Desert Varnishes are dark rock coatings that are composed of clay minerals cemented to the underlying rock by oxides of Mn, Fe, or both.
Weathering a rock will breakdown and decay the lithosphere into products that are in equilibrium with conditions at or near the earth’s (rock’s) surface. Weathering processes also forms new compounds.
Dorn, Rock Coatings, 1998

6. Approach:
Collected rock samples from around the world in arid climates.
Multiple spectral readings of fresh and desert varnished sides
SW U.S., India, Argentina
Obtained TIR emission spectroscopy
Compare terrestrial samples to TES STII spectral readings.

7. Results: Fresh Surfaces were primarily basalt and obsidian
Desert Varnishes were the same on various fresh surfaces

8. Results:
The main component of desert varnish is likely the clay Montmorillonite

9. Results:
Varnishes vary considerably within the individual rocks and within the same varnish.

10. Conclusions:
Desert varnishes uses the surrounding environment for material to create the layer
Surface Type II rocks on Mars are not completely varnished by clay materials

11. Acknowledgements
RATW and MSFF
NASA Space Grant