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Neoarchean Microfossils and Microbialites Inform the Search for Extraterrestrial Life in the Solar System

Corpolongo, Andrea
http://orcid.org/0000-0002-8623-358X
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1721145153623216

Abstract Details

2024, PhD, University of Cincinnati, Arts and Sciences: Geology.
The Great Oxygenation Event is the period, between 2.3 and 2.4 billion years ago, when oxygen began to accumulate in Earth's atmosphere. It was arguably the most consequential change in the history of our planet and the life that inhabits it. Knowledge of the events that led to this change is of great scientific interest because it will help us understand how Earth became a planet that can support complex multicellular organisms, including humans, and determine what to look for when planning missions to seek evidence of life beyond Earth, such as NASA’s current Mars 2020 mission. This dissertation presents studies of fossilized microorganisms (microfossils) and microbially-influenced carbonate (carbonate microbialites) that formed shortly before the Great Oxygenation Event. Three-dimensional reconstructions along with photomicrography reveal the morphologies and habits of the preserved microbial communities to provide a better understanding of the types of microorganisms that existed just before the Great Oxygenation Event. The results suggest that microorganisms may have evolved to take advantage of transient microoxic-sulfidic interfaces 200 million years before the Great Oxygenation Event. Petrographic examinations and Raman spectroscopy provide insight into the geological processes that led to the preservation of these microfossils and microbialites. Understanding the preservation and detection of life’s signatures, or biosignatures, on Earth is both necessary to the study of life on Earth and foundational to planning missions to seek biosignatures elsewhere in the solar system. The results of this work include the first reported instance of early diagenetic silicification that occurred via silica spherule nucleation directly on organic matter in a deep-water environment. To support the interpretation of DUV Raman data collected on Mars, this dissertation presents a comparison of Raman data collected from terrestrial biogenic microbialites with a Mars 2020 analog DUV Raman and fluorescence spectrometer and a visible Raman spectrometer. The results of this work indicate that the positions of peaks in the fingerprint region of calcite and dolomite DUV Raman spectra are approximately 10 wavenumbers lower than they are in visible Raman spectra, which suggests that data collected with visible Raman spectrometers cannot be relied on to interpret DUV Raman carbonate spectra. Finally, this dissertation presents an early interpretation of the first Raman mapping performed on the surface of another planetary body, which took place during the first science campaign of NASA’s Mars 2020 mission. This data interpretation supports the claim that Jezero Crater, the site of the Mars 2020 mission, was once a habitable environment and is currently host to multiple mineral deposits with a high biosignature preservation potential. In addition, this work has provided a foundation for the interpretation of subsequent DUV Raman data collected during the Mars 2020 mission.
Andrew Czaja, Ph.D. (Committee Chair)
Carlton Brett, Ph.D. (Committee Member)
Susannah Porter, Ph.D. (Committee Member)
Annette Rowe, Ph.D. (Committee Member)
Joshua Miller, Ph.D. (Committee Member)
204 p.
Paleontology
Microbial Sulfur Oxidation; Great Oxygenation Event; Great Oxidation Event; Astrobiology; Mars; Archean

Recommended Citations

Citations

  • Corpolongo, A. (2024). Neoarchean Microfossils and Microbialites Inform the Search for Extraterrestrial Life in the Solar System [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1721145153623216

    APA Style (7th edition)

  • Corpolongo, Andrea. Neoarchean Microfossils and Microbialites Inform the Search for Extraterrestrial Life in the Solar System. 2024. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1721145153623216.

    MLA Style (8th edition)

  • Corpolongo, Andrea. "Neoarchean Microfossils and Microbialites Inform the Search for Extraterrestrial Life in the Solar System." Doctoral dissertation, University of Cincinnati, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1721145153623216

    Chicago Manual of Style (17th edition)

ucin1721145153623216
139
© 2024, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.