{"682768":{"#nid":"682768","#data":{"type":"event","title":"PhD Defense by Emmy Hughes ","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003EEmmy Hughes PhD Defense\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EJune 25th, 1 p.m., Ford ES\u0026amp;T L1205\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EZoom link:\u0026nbsp;\u003C\/strong\u003E\u003Ca href=\u0022https:\/\/gatech.zoom.us\/j\/96940711745\u0022 target=\u0022_blank\u0022\u003Ehttps:\/\/gatech.zoom.us\/j\/96940711745\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EDissertation title:\u0026nbsp;\u003C\/strong\u003EMartian Salts and Surface Materials as Paleoclimate Indicators through Orbital, In Situ, and Analogue Analyses\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E James Wray (advisor), Frances Rivera-Hern\u00e1ndez (co-advisor), Chris Carr, Suniti Karunatillake, Ben Tutolo.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EMars\u2014a cold, dry planet today\u2014one was home to flowing, pooling, and concentrating liquid water. The aqueous processes that occurred billions of years ago on the surface of Mars left traces, often in the form of minerals. The composition, structure, and chemistry of these minerals records the environments in which they formed, including the temperature of fluids in an environment. Here, we investigate the paleoclimate of Mars in three distinct ways: through orbital data of a proposed ancient hydrothermal lake on Mars; in situ data of an ancient, habitable lake on Mars; and in situ study of a series of lakes on earth that serve as Mars analogues. We rely on spectroscopy\u2014primarily, near-infrared, Raman, laser induced spectroscopy, and X-ray fluorescence\u2014to determine the mineralogical and chemical makeup of climate indexing minerals, as proxies for their environments. We find that the proposed ancient hydrothermal system on Mars (Eridania Basin in the Mars southern highlands) has minimal definitive surface evidence for hydrothermalism, and the mineralogy and geochemistry is more consistent with low-temperature, minimal water-to-rock weathering of basaltic materials. This suggests a limited watershed and may fit into a broader history of a colder early Mars. Study of the Mars analogue Basque Lakes in British Columbia, Canada, reveals a suite of metastable minerals forming in brine pools and efflorescent crusts seasonally, and indicates that cold-temperature salts form from freezing brines, which might act as cold-climate indicators when preserved in the rock record. We identify a region of the near-infrared that is particularly useful for identifying warm- and cold-temperature salts on Mars and Earth. Finally within Gale crater, Mars (the landing site of the Mars \u003Cem\u003ECuriosity\u003C\/em\u003E rover), we report on unusual geochemical signatures within dark-toned laminations in sulfate-bearing strata, suggesting that likely warm diagenetic fluids permeated bedding planes to form hydrated Na-Mg-sulfates and fluorine-bearing minerals. These fluids might be linked to major climate cycles forming the stratigraphy in this region\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EMartian Salts and Surface Materials as Paleoclimate Indicators through Orbital, In Situ, and Analogue Analyses\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Martian Salts and Surface Materials as Paleoclimate Indicators through Orbital, In Situ, and Analogue Analyses"}],"uid":"27707","created_gmt":"2025-06-11 16:56:00","changed_gmt":"2025-06-11 16:56:40","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2025-07-25T13:00:01-04:00","event_time_end":"2025-07-25T15:00:00-04:00","event_time_end_last":"2025-07-25T15:00:00-04:00","gmt_time_start":"2025-07-25 17:00:01","gmt_time_end":"2025-07-25 19:00:00","gmt_time_end_last":"2025-07-25 19:00:00","rrule":null,"timezone":"America\/New_York"},"location":"Ford ES\u0026T L1205","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}