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Application of TES Spectral Data to Rock Varnish. Taylor Feiereisel Mentors: Shawn Wright Laurie Rogers. 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
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Application of TES Spectral Data to Rock Varnish Taylor Feiereisel Mentors: Shawn Wright Laurie Rogers
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
Mars TIR History: Mars Global Surveyor Mars Odyssey 2001 THEMIS TES
STI and STII Sites Northern Hemisphere Sources: Wyatt and McSween, 2002; Hamilton et al., 2003 Southern Hemisphere
Rock Coatings: • Rock Coatings are additional sub aerial layers on a rock derived through multiple biochemical and geomorphologic processes. • 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. • Desert Varnishes are dark rock coatings that are composed of clay minerals cemented to the underlying rock by oxides of Mn, Fe, or both. Dorn, Rock Coatings, 1998
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.
Results: • Fresh Surfaces were primarily basalt and obsidian • Desert Varnishes were the same on various fresh surfaces
Results: • The main component of desert varnish is likely the clay Montmorillonite
Results: • Varnishes vary considerably within the individual rocks and within the same varnish.
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
Acknowledgements RATW and MSFF NASA Space Grant