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A Multi-Faceted Approach to Characterize Acid-Sulfate Alteration Processes in Volcanic

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A Multi-Faceted Approach to Characterize Acid-Sulfate Alteration Processes in Volcanic A multi-faceted approach to characterize acid-sulfate alteration processes in volcanic hydrothermal systems on Earth and Mars by Emma Cordts Marcucci B.S., Johns Hopkins University, 2008 A thesis submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirement for the degree of Doctor of Philosophy Department of Geological Sciences 2013 This thesis entitled: A multi-faceted approach to characterize acid-sulfate alteration processes in volcanic hydrothermal systems on Earth and Mars written by Emma Cordts Marcucci has been approved for the Department of Geological Sciences ____________________________________ Dr. Brian M. Hynek ____________________________________ Dr. Lang Farmer ____________________________________ Dr. Tom McCollom ____________________________________ Dr. Alexis Templeton ____________________________________ Dr. Steve Schmidt Date: ______________________ The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. Marcucci, Emma Cordts (Ph.D., Geological Sciences) A multi-faceted approach to characterize acid-sulfate alteration processes in volcanic hydrothermal systems on Earth and Mars Thesis directed by Associate Professor Brian M. Hynek Abstract Acid-sulfate alteration is a dominant weathering process in high temperature, low pH, sulfur-rich volcanic environments. Additionally, hydrothermal environments have been proposed as locations where life could have originated on Earth. Based on the extensive evidence of flowing surface water and persistent volcanism, similar locations and processes could have existed on early Mars. Globally observed alteration mineral assemblages likely represent relic Martian hydrothermal settings. Yet the limited understanding of environmental controls, limits the confidence of interpreting the paleoconditions of these hydrothermal systems and assessing their habitability to support microbial life. This thesis presents a series of laboratory experiments, geochemical models, analog fieldwork, and Martian remote sensing to characterize distinguishing features and controls of acid-sulfate alteration. The experiments and models were designed to replicate alteration is a highly acidic, sulfurous, and hot field sites. The basaltic minerals were individually reacted in both experimental and model simulations with varying initial parameters to infer the geochemical pathways of acid-sulfate alteration on Earth and Mars. It was found that for a specific starting material, secondary mineralogies were consistent. Variations in pH, temperature and duration affected the abundance, shape, and size of mineral products. Additionally evaporation played a key role in secondary deposits; therefore, both alteration and evaporitic processes need to be taken into consideration. Analog volcanic sites in Nicaragua were used to supplement this work and highlight differences between natural iii and simulated alteration. In situ visible near-infrared spectroscopy demonstrated that primary lithology and gas chemistry were dominant controls of alteration, with secondary effects from environmental controls, such as temperature and pH. The spectroscopic research from the field was directly related to Mars observations in Noctis Labyrinthus, Terra Sirenum, Syrtis Major, and Mawrth Vallis to help interpret ancient conditions in those settings. To further apply the results from experiments, models, and fieldwork, Coprates Chasma in eastern Valles Marineris was studied using mineralogical and morphological data. Emplacement of alteration minerals indicated both pre- and post-rifting hydrothermal activity. Smaller southern grabens appeared to have experienced a unique alteration. In summary, this dissertation presents research that contributes to the understanding of the geological evolution of Mars and potentially habitability. iv Acknowledgements I would most like to thank my advisor, Brian Hynek, for his guidance through this project and his patience reading and re-reading many drafts of my articles. I would also like to thank Tom McCollom for use of his laboratory for experimental work and advice on geochemical modeling. The fieldwork component of this research would not have been possible without the in-country assistance of INETER and the spectral interpretation help from Kathryn Young and Mikki Osterloo. I would also like to thank Karyn Rogers for introducing me to field techniques for biological samples. Chapters 2-5 have been or will be submitted for publication in scientific journals and have benefitted greatly from: Brian Hynek, Tom McCollom, Mikki Osterloo, Stuart Robbins, Karyn Rogers, and Kathryn Young. A number of friends and family provided insightful comments on the introduction of this these, including Barbara Cordts, Grace Cordts, Elizabeth Frank, Ulyana Horodyskyj, Kristin Lucas, Andrea Marcucci, Dan Marcucci, Olivia Marcucci, Macy Marcucci, Michael O’Keefe, Mikki Osterloo, Ernesto Perez, Stuart Robbins, and Nadine Semer. Finally, I would like to thank my family and friends, the wonderful actors and technical crew of Centerstage Theater Company and the instructors at FAC for helping me remain sane and healthy through the intense process to obtain a Ph.D. The science chapters 2-4 presented in this thesis have been submitted or will soon be submitted to journals. Acknowledgements for each section follow: Chapter 2: We would like to acknowledge the Laboratory for Environmental and Geological Studies (LEGS) at the University of Colorado at Boulder’s (UCB) Department of Geological Sciences for completing the fluid analysis. The XRD instrument used is also at UCB’s Department of Geological Sciences. The SEM/EDS instrument is housed at the Nanomaterials Characterization Facility on the UCB campus. Additionally, we thank the v Nicaraguan government agency Instituto Nicaragüense de Estudios Territoriales for logistical support in Nicaragua. This work was supported by NASA NESSF Grant # NNX10AU39H. Thank you to T. McCollom for insight comments on experiment and model design and analysis, as well as, use of laboratory space and manuscript edits. Many thanks to M. Osterloo, S. Robbins, and D. Marcucci for editorial comments that greatly improved this manuscript. Chapter 3: We would like to thank Analytical Spectral Devices, Inc. in Boulder, CO for the use of the TerraSpec4 instrument used during this field campaign, particularly those individuals who worked hard to facilitate the loan and training in a limited timeframe. Additionally, we thank the Nicaraguan government agency Instituto Nicaragüense de Estudios Territoriales for in country support of this study. Thanks to Mikki Osterloo for useful discussions regarding this manuscript. This work was supported by NASA NESSF Award #NNX10AU39H, the CU Department of Geological Sciences Longley-Wahlstrom-Werner Graduate Research Award, and NASA Exobiology Award #NNX08AQ11G and NASA Early Career Award #NNX12AF20G to B. M. Hynek. Chapter 4: We would like to thank Kathryn Kierein-Young for the custom ENVI/IDL spectra clean program and support in CRISM analyses. We would like to thank Mikki Osterloo for assistance with the analysis of THEMIS spectral data. We thank the CRISM, THEMIS, HiRISE, and CTX teams for the acquisition of data used in this study. This work was supported by NASA NESSF Grant # NNX10AU39H. vi Table of Contents Acknowledgements ....................................................................................................................... v Table of Contents ........................................................................................................................ vii List of Tables ................................................................................................................................ ix List of Figures ................................................................................................................................ x 1. Introduction .............................................................................................................................. 1 1.1 Historical Observations ..................................................................................................... 1 1.2 Spacecraft Exploration ...................................................................................................... 4 1.2.1 Brief History of Water and Alteration Environments ................................................... 7 1.3 Morphological Evidence .................................................................................................... 9 1.3.1 Orbital Evidence for Ancient Surface Water ................................................................ 9 1.3.2 Orbital Evidence for Ancient Subsurface Water ........................................................ 14 1.3.3 Orbital Evidence for Modern Water ........................................................................... 15 1.3.4 In situ Evidence for Ancient Water ............................................................................ 16 1.3.5 Modern Ground Ice ..................................................................................................... 19 1.4 Chemical and mineralogical evidence ............................................................................ 19 1.4.1 Iron minerals ..............................................................................................................
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