Application of TES Spectral Application of TES Spectral Data to Rock VarnishData to Rock Varnish

Taylor FeiereiselTaylor Feiereisel

Mentors: Shawn WrightMentors: Shawn Wright Laurie RogersLaurie Rogers

OverviewOverview:: Orbital TES thermal infrared (TIR) spectral data Orbital TES thermal infrared (TIR) spectral data

concludes two different types of rock surfaces on concludes two different types of rock surfaces on Mars in the low albedo regions of MarsMars in the low albedo regions of Mars Surface Type I (STI) = BasaltSurface Type I (STI) = Basalt Surface Type II (STII) = ???Surface Type II (STII) = ???

Clay-manganiferous rock coatings called desert Clay-manganiferous rock coatings called desert varnish could manipulate the TES TIR STII spectral varnish could manipulate the TES TIR STII spectral data.data.

Approach: Laboratory SpectroscopyApproach: Laboratory Spectroscopy Results and ImplicationsResults and Implications AcknowledgementsAcknowledgements

Mars TIR Mars TIR History:History:

Mars Global Surveyor Mars Odyssey 2001

TESTHEMIS

STI and STII SitesSTI and STII Sites

Northern Hemisphere

Southern Hemisphere Sources: Wyatt and McSween, 2002; Hamilton et al., 2003

Rock Coatings:Rock Coatings:

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.

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.

Dorn, Rock Coatings, 1998

Approach:Approach: Collected rock samples from around the Collected rock samples from around the

world in arid climates.world in arid climates. Multiple spectral readings of fresh and Multiple spectral readings of fresh and

desert varnished sidesdesert varnished sides SW U.S., India, ArgentinaSW U.S., India, Argentina Obtained TIR emission spectroscopyObtained TIR emission spectroscopy

Compare terrestrial samples to TES STII Compare terrestrial samples to TES STII spectral readings.spectral readings.

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

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

Varnishes vary considerably within the individual rocks Varnishes vary considerably within the individual rocks and within the same varnish.and within the same varnish.

Results:Results:

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

AcknowledgementsAcknowledgements

RATW and MSFF NASA Space Grant