This study looks at two iron-rich phyllosilicates, which may be present on Mars. The minerals, greenalite and hisingerite, are rich in iron-II and iron-III, respectively. Small samples (~0.40 grams) of each mineral were crushed and heated in a Lindberg Tube Oven for approximately twenty-four hours at temperatures selected to mimic lava flows and impact events. Following heating, each sample was placed in a Fourier Transform Infrared (FT-IR) spectrometer to collect the near- and mid-infrared spectra. The spectra allowed for these terrestrial analogs to be analyzed with regards to how their structure breaks down with increasing temperature. The samples' colors were also recorded and show varying degrees of oxidation following heating, which is expected in the oxygen-rich ambient atmosphere they were heated under. It is apparent from the spectra that for greenalite, heating at 765°C and higher breaks the mineral down into hematite and a high-temperature silica, such as cristobalite. Hisingerite exhibits the same behavior, but its basic spectra structure is retained in the 710°C sample. The near-infrared spectra were compared with spectra from different locations on Mars, collected by both Mars Express and the Mars Reconnaissance Orbiter. The spectra were also compared with each other to allow for analysis of how the iron-III polymorph of a mineral reacts differently from its iron-II counterpart. The multiple facets of the study aim to help understand the current state, history, and evolution of Mars, specifically if clay formation occurred deep in Mars' past or as the result of impact-induced hydrothermal activity more recently in its history.
","abstract_html":"<p>This study looks at two iron-rich phyllosilicates, which may be present on Mars. The minerals, greenalite and hisingerite, are rich in iron-II and iron-III, respectively. Small samples (~0.40 grams) of each mineral were crushed and heated in a Lindberg Tube Oven for approximately twenty-four hours at temperatures selected to mimic lava flows and impact events. Following heating, each sample was placed in a Fourier Transform Infrared (FT-IR) spectrometer to collect the near- and mid-infrared spectra. The spectra allowed for these terrestrial analogs to be analyzed with regards to how their structure breaks down with increasing temperature. The samples' colors were also recorded and show varying degrees of oxidation following heating, which is expected in the oxygen-rich ambient atmosphere they were heated under. It is apparent from the spectra that for greenalite, heating at 765°C and higher breaks the mineral down into hematite and a high-temperature silica, such as cristobalite. Hisingerite exhibits the same behavior, but its basic spectra structure is retained in the 710°C sample. The near-infrared spectra were compared with spectra from different locations on Mars, collected by both Mars Express and the Mars Reconnaissance Orbiter. The spectra were also compared with each other to allow for analysis of how the iron-III polymorph of a mineral reacts differently from its iron-II counterpart. The multiple facets of the study aim to help understand the current state, history, and evolution of Mars, specifically if clay formation occurred deep in Mars' past or as the result of impact-induced hydrothermal activity more recently in its history.</p>","abstract_has_math":false,"creators":["Bryan, William Thomas"],"institution":null,"degree_name":"Master of Science in Space & Planetary Sciences (MS)","degree_level":"Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Dixon, John C.","Roe, Larry A."],"advisors":["Chevrier, Vincent F."],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-12-01T08:00:00Z","date_published":"2013-12-01T08:00:00Z","updated_at":"2026-07-24T01:00:19Z","subjects":["Earth sciences","Clays","Grrenlalite","Hisingerite","Infrared","Mars","Spectra","Mineral Physics","Physical Processes","The Sun and the Solar System"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.uark.edu/etd/941","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dixon, John C.","Roe, Larry A."]},{"key":"dc:contributor.advisor","label":"Advisor","values":["Chevrier, Vincent F."]},{"key":"dc:creator","label":"Author","values":["Bryan, William Thomas"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-09-29T07:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science in Space & Planetary Sciences (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Earth sciences","Clays","Grrenlalite","Hisingerite","Infrared","Mars","Spectra","Mineral Physics","Physical Processes","The Sun and the Solar System"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.uark.edu/etd/941"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This study looks at two iron-rich phyllosilicates, which may be present on Mars. The minerals, greenalite and hisingerite, are rich in iron-II and iron-III, respectively. Small samples (~0.40 grams) of each mineral were crushed and heated in a Lindberg Tube Oven for approximately twenty-four hours at temperatures selected to mimic lava flows and impact events. Following heating, each sample was placed in a Fourier Transform Infrared (FT-IR) spectrometer to collect the near- and mid-infrared spectra. The spectra allowed for these terrestrial analogs to be analyzed with regards to how their structure breaks down with increasing temperature. The samples' colors were also recorded and show varying degrees of oxidation following heating, which is expected in the oxygen-rich ambient atmosphere they were heated under. It is apparent from the spectra that for greenalite, heating at 765°C and higher breaks the mineral down into hematite and a high-temperature silica, such as cristobalite. Hisingerite exhibits the same behavior, but its basic spectra structure is retained in the 710°C sample. The near-infrared spectra were compared with spectra from different locations on Mars, collected by both Mars Express and the Mars Reconnaissance Orbiter. The spectra were also compared with each other to allow for analysis of how the iron-III polymorph of a mineral reacts differently from its iron-II counterpart. The multiple facets of the study aim to help understand the current state, history, and evolution of Mars, specifically if clay formation occurred deep in Mars' past or as the result of impact-induced hydrothermal activity more recently in its history.
"]},{"key":"dc:title","label":"Title","values":["Infrared Spectra Analysis of Thermally Altered Iron Phyllosilicates and the Implications for Mars"]}]}],"canonical_facts":{"dc:contributor":["Dixon, John C.","Roe, Larry A."],"dc:contributor.advisor":["Chevrier, Vincent F."],"dc:creator":["Bryan, William Thomas"],"dc:date":["2013"],"dc:date.available":["2017-09-29T07:00:00Z"],"dc:description.abstract":["This study looks at two iron-rich phyllosilicates, which may be present on Mars. The minerals, greenalite and hisingerite, are rich in iron-II and iron-III, respectively. Small samples (~0.40 grams) of each mineral were crushed and heated in a Lindberg Tube Oven for approximately twenty-four hours at temperatures selected to mimic lava flows and impact events. Following heating, each sample was placed in a Fourier Transform Infrared (FT-IR) spectrometer to collect the near- and mid-infrared spectra. The spectra allowed for these terrestrial analogs to be analyzed with regards to how their structure breaks down with increasing temperature. The samples' colors were also recorded and show varying degrees of oxidation following heating, which is expected in the oxygen-rich ambient atmosphere they were heated under. It is apparent from the spectra that for greenalite, heating at 765°C and higher breaks the mineral down into hematite and a high-temperature silica, such as cristobalite. Hisingerite exhibits the same behavior, but its basic spectra structure is retained in the 710°C sample. The near-infrared spectra were compared with spectra from different locations on Mars, collected by both Mars Express and the Mars Reconnaissance Orbiter. The spectra were also compared with each other to allow for analysis of how the iron-III polymorph of a mineral reacts differently from its iron-II counterpart. The multiple facets of the study aim to help understand the current state, history, and evolution of Mars, specifically if clay formation occurred deep in Mars' past or as the result of impact-induced hydrothermal activity more recently in its history.
"],"dc:identifier":["https://scholarworks.uark.edu/etd/941"],"dc:subject":["Earth sciences","Clays","Grrenlalite","Hisingerite","Infrared","Mars","Spectra","Mineral Physics","Physical Processes","The Sun and the Solar System"],"dc:title":["Infrared Spectra Analysis of Thermally Altered Iron Phyllosilicates and the Implications for Mars"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science in Space & Planetary Sciences (MS)"]},"updated_at":"2026-07-24T01:00:19Z"}