- Title Information
- Title
- Clays and Opals on Mars: Implications for Water-Rock Interactions Through Time
- Name:
Personal
- Name Part
- Sun, Vivian
- Role
- Role Term:
Text
- creator
- Name:
Personal
- Name Part
- Milliken, Ralph
- Role
- Role Term:
Text
- Advisor
- Name:
Personal
- Name Part
- Mustard, John
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Russell, James
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Pieters, Carle
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Ruff, Steve
- Role
- Role Term:
Text
- Reader
- Name:
Corporate
- Name Part
- Brown University. Department of Earth, Environmental, and Planetary Sciences
- Role
- Role Term:
Text
- sponsor
- Origin Information
- Copyright Date
- 2017
- Physical Description
- Extent
- 16, 431 p.
- digitalOrigin
- born digital
- Note:
thesis
- Thesis (Ph. D.)--Brown University, 2017
- Genre (aat)
- theses
- Abstract
- Diverse hydrous minerals have been identified on Mars and suggest a rich history of water-rock interactions in a variety of aqueous environments. Fe/Mg clays and hydrated/opaline silica comprise the two largest groups of hydrous minerals detected on Mars, and are distinctly associated with Noachian and Hesperian terrains respectively. These clays and opals also have characteristic properties where increasing exposure to water will convert Fe/Mg smectite to chlorite, and amorphous opal-A to more crystalline opal-CT, opal-C, and quartz. Distinguishing between these mineral forms therefore allows us to make inferences of aqueous activity in an environment and carries implications for biosignature preservation. This dissertation uses near-infrared spectroscopy to explore the distribution and types of Fe/Mg clays and opals on Mars and infer the nature and timing of the aqueous processes that formed them. The major findings from this work are as follows. 1) From a global survey of martian central peak craters, we find that Fe/Mg clays formed primarily during the Noachian but could have formed in Hesperian or Amazonian crater environments relatively recently in Mars’ past. 2) Chlorite occurrences increase with crater excavation depth, suggesting smectite-to-chlorite diagenesis within the martian crust. 3) Opal-A and opal-CT can be distinguished in near-infrared laboratory spectra due to the different distribution and behavior of H2O in these two phases. 4) Based on laboratory hydration experiments, we find that opals will readily exchange H2O with a Mars-like atmosphere and exhibit spectral changes that are theoretically observable from Mars orbital spectra. 5) Opal-A and opal-CT are both present on Mars but appear correlated with geologic setting on a global scale. Opal-A is associated with bedrock, while opal-CT is associated with unconsolidated deposits, suggesting differences in exposure age or facilitated opal maturation in unconsolidated deposits. These results add to the increasing evidence for diagenetic alteration of both clays and opals that suggest more extensive aqueous processes in Mars’ history.
- Subject
- Topic
- Spectroscopy
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01094469")
- Topic
- Remote sensing
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01243063")
- Topic
- Mars (Planet)
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00863854")
- Topic
- Clay minerals
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01046035")
- Topic
- Opals
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00892271")
- Topic
- Diagenesis
- Language
- Language Term (ISO639-2B)
- English
- Record Information
- Record Content Source (marcorg)
- RPB
- Record Creation Date
(encoding="iso8601")
- 20170616
- Identifier:
DOI
- 10.7301/Z08G8J58
- Access Condition:
rights statement
(href="http://rightsstatements.org/vocab/InC/1.0/")
- In Copyright
- Access Condition:
restriction on access
- Collection is open for research.
- Type of Resource (primo)
- dissertations