Trace gas analysis in Earth systems plays an important role in planetary research. Bernard (1976) and Whiticar (1999) proposed that biologically produced methane and thermogenically or geologically produced methane could be differentiated in marine environments through isotopic analysis coupled with methane to higher n-alkane gas concentration ratios. This differentiation is important to the study of exobiology; the ability to determine a biological source of atmospheric gas production through isotopic and/or concentration analysis could prove critical to the search for a "second genesis" within our solar system, greatly increasing the probability of life throughout the universe. It is hypothesized that the earliest forms of life on Earth were methanogenic archaea developing in extreme anaerobic conditions. These conditions include high temperature >90°C hydrothermal vents as well as hypersaline environments where archaea have been found to exist in present day (Rasmussen 2000, Huber et al., 1989, Kelley et al., 2005 ). Analogous hypersaline paleoenvironments have been found to exist on Mars (Osterloo, M.M. et al., 2008). Tazaz (2012) proposed an extension to the biogenic isotopic boundaries of methane from hypersaline environments investigated in Baja, Mexico. Here we reconfirm Tazaz's results from Baja while showing a similar isotopic composition of methane in hypersaline environments in Atacama, Chile. Tazaz (2012) also proposed further research into low methane to higher n-alkane gas ratios found in field samples from Baja, Mexico. We show here through lab incubation experiments of sediment collected in Baja, Mexico and Atacama, Chile that these low ratios are primarily due to the biogenic production of ethane in hypersaline environments. Experiments were done with various substrate amendments to investigate the greatest yield of ethane and the effects of inhibiting sulfate reducing bacteria. Given the significance of such findings, it is essential to examine the extremophiles that exist in hypersaline environments to gain a better understanding of the biomarkers in trace gas analysis. / A Thesis submitted to the Department of Earth, Ocean and Atmospheric Science in partial fulfillment of the Master of Science. / Spring Semester, 2015. / January 30, 2015. / Astrobiology, Exobiology, Extremophiles, Hypersaline / Includes bibliographical references. / Jeffery Chanton, Professor Directing Thesis; Olivia Mason, Committee Member; Angela Knapp, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_253000 |
| Contributors | Mauney, Michael Tyler (authoraut), Chanton, Jeffrey P. (professor directing thesis), Mason, Olivia Underwood (committee member), Knapp, Angela Noel (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Earth, Ocean, and Atmospheric Science (degree granting department) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource (92 pages), computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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