Abstract
Minerals have characteristic absorption features in the visible and near-infrared wavelength range, which can be detected in remotely sensed observations using methods such as spectral parameter maps or modeled via spectral mixtures. My dissertation uses both methods on orbital and ground-based single-scattering albedo data to assess the surface compositions of Meridiani Planum and Oxia Planum, regions of Mars that are rich in secondary minerals. A probabilistic approach to spectral unmixing was adopted to account for the nonuniqueness of model solutions, with endmember abundance and grain size maps being produced for Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) orbital images. For the Oxia Planum study, the probabilistic algorithm was modified to accommodate a sparse unmixing technique, in order to determine the optimal combination of endmembers on a per-pixel basis. The unmixing results for Meridiani Planum CRISM data, together with Panoramic Camera-based spectral mixing models from the Mars Exploration Rover Opportunity, suggest that modern winds are enhancing ferric absorption signatures in this area by removing dust from surfaces. In Oxia Planum, spectral parameter maps are consistent with detections of clay-bearing materials in previous works. Model results from the sparse probabilistic unmixing corroborate the clay detections and show that carbonates may also associate with the clays in some terrains, offering more insight into the formation history of the region. This research demonstrates the continued usefulness of spectral mixture analysis for compositional studies, helping us to better understand the geology of Mars and to aid future exploration of its surface.
Committee Chair
Bradley Jolliff
Committee Members
Jeffrey Catalano; Joseph O’Sullivan; Paul Byrne; Roger Michaelides
Degree
Doctor of Philosophy (PhD)
Author's Department
Earth & Planetary Sciences
Document Type
Dissertation
Date of Award
8-18-2025
Language
English (en)
DOI
https://doi.org/10.7936/0j5c-mg12
Author's ORCID
https://orcid.org/0000-0001-7066-1072
Recommended Citation
Condus, Thomas Jake, "Spectral Mixture Analyses of Hematite-Rich and Clay-Bearing Terrains in Meridiani and Oxia Planum, Mars" (2025). Arts & Sciences Theses and Dissertations. 3581.
The definitive version is available at https://doi.org/10.7936/0j5c-mg12