Understanding the composition and evolution of the Martian surface using thermal infrared laboratory analyses and remote sensing

• Main Author: Koeppen, William Carl
• Language: en-US
• Published: 2011
• Online Access: http://hdl.handle.net/10125/20627

Thesis (Ph.D.)--University of Hawaii at Manoa, 2008. === In this work, thermal infrared (TIR) spectroscopy is used to refine and advance our understanding of the mineralogic composition of the Martian surface. The distinctiveness of glasses and phyllosilicates in TIR spectra is quantified using discriminant analysis and linear least squares modeling of numerical mixtures. Uncertainties in the modeled abundances of glasses and phyllosilicates are +/-15% when the glass components in the mixture are included in the model, whereas uncertainties rise to +/-65% when glass components are arbitrarily excluded from the model. When these uncertainties are applied to glass and phyllosilicate abundances on Mars derived from Thermal Emission Spectrometer (TES) data we find that glass is a likely component of the Martian surface. Spectral indexing and linear least squares modeling are used to compare laboratory-measured TIR emission spectra of Fo91, Fo68, Fo53, Fo39, Fo18, and Fo1 olivine samples to TES data and map the global distribution, composition, and abundance of olivine on Mars. Fo91 spectral shapes are identified in the rims of the Hellas and Argyre impact basins. The Fo68 and Fo 53 olivine spectral shapes are common in the southern highlands, chasmata, outflow channels, and are the most common compositions in the Nili Fossae region. The presence of the Fo39 olivine composition suggests that olivine on Mars is more iron-rich than olivine in most Martian meteorites. The mineralogy, thermophysical properties, stratigraphy, and visual character of four locales in Terra Tyrrhena identified by different compositions of olivine (Fo91, Fo68, Fo53, and Fo39 ) are investigated. Fo91-enriched materials occur as thin Noachian lava flows, perhaps associated with the Hellas impact basin. Fo 68-enriched materials are present throughout Terra Tyrrhena, and in some places have interacted with liquid water at the end of the Noachian epoch; the presence of olivine constrains the total duration of aqueous activity during this period to <∼20,000 years. Fo53 and Fo39 -enriched materials are interpreted as Hesperian-aged lavas that erupted after the end of the Noachian aqueous activity. The settings of olivine-enriched materials suggest that surface materials in Terra Tyrrhena may have been more enriched in olivine before aqueous activity associated with the end of the Noachian epoch. === Includes bibliographical references (leaves 175-190). === Also available by subscription via World Wide Web === 190 leaves, bound 29 cm