Effects of pure silica coatings on thermal emission spectra of basaltic rocks: Considerations for Martian surface mineralogy

Michael D. Kraft, Joseph R. Michalski, Thomas Sharp

Research output: Contribution to journalArticle

88 Scopus citations

Abstract

On Mars, silica derived from chemical weathering could precipitate to coat rocks and particles. We suggest that rock coatings of secondary amorphous silica may account for a widespread Martian surface spectral unit previously modeled as andesite or weathered basalt. In a laboratory study, we investigated the effects of synthetic silica coatings on thermal infrared (TIR) spectroscopic measurements. Secondary amorphous silica is spectrally similar to silicate glass and clay spectra used in previous spectroscopic models. Silica coating and substrate spectra combine nonlinearly to produce a composite spectrum of a coated rock. Silica coatings <10 μm thick effectively mask the spectral contribution of a silicate substrate. Therefore, the capability of volumetrically small amounts of silica present as thin coatings on rocks should be considered when seeking explanations for spectral variability of Martian surface materials.

Original languageEnglish (US)
Pages (from-to)PLA 5-1 - PLA 5-4
JournalGeophysical Research Letters
Volume30
Issue number24
DOIs
StatePublished - Dec 15 2003

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

Fingerprint Dive into the research topics of 'Effects of pure silica coatings on thermal emission spectra of basaltic rocks: Considerations for Martian surface mineralogy'. Together they form a unique fingerprint.

  • Cite this