T. F. Bristow
A5015494306- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Geochemistry and Geologic Mapping
- Isotope Analysis in Ecology
- Hydrocarbon exploration and reservoir analysis
- Geological and Geochemical Analysis
- Space Science and Extraterrestrial Life
- Clay minerals and soil interactions
- Research Data Management Practices
- Methane Hydrates and Related Phenomena
- Nuclear Physics and Applications
- Scientific Computing and Data Management
- Spaceflight effects on biology
- Radioactivity and Radon Measurements
- Geochemistry and Elemental Analysis
- X-ray Spectroscopy and Fluorescence Analysis
- Mineralogy and Gemology Studies
- Spacecraft and Cryogenic Technologies
- Iron oxide chemistry and applications
- Advanced X-ray Imaging Techniques
- X-ray Diffraction in Crystallography
- Biocrusts and Microbial Ecology
Ames Research Center
2015-2024
Honeybee Robotics (United States)
2021
Aix-Marseille Université
2021
Johnson Space Center
2021
Jacobs (United States)
2021
University of Arizona
2021
Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2021
Centre National de la Recherche Scientifique
2021
Chesapeake Bay Program
2020
NASA Research Park
2020
The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of environment that would have been suited support a martian biosphere founded on chemolithoautotrophy. This aqueous was characterized by neutral pH, low salinity, variable redox states both iron sulfur species. Carbon, hydrogen, oxygen, sulfur, nitrogen, phosphorus were measured directly as key biogenic elements; inference, is assumed available. probably had...
Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, calcium sulfates, iron oxide or hydroxides, sulfides, amorphous material, trioctahedral smectites. smectite has basal spacing of ~10 angstroms, indicating little interlayer hydration. Cumberland both ~13.2 angstroms. larger suggests a partially chloritized magnesium facilitating H2O retention. Basaltic minerals...
The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian bedform in Gale crater. Analysis with Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, pigeonite, minor K-feldspar, magnetite, quartz, anhydrite, hematite, ilmenite. phases are present at, or near, detection limits. also contains 27 ± 14 weight percent amorphous material, likely containing multiple Fe 3+ -...
The Rocknest aeolian deposit is similar to features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. fraction of sand <150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage ~45% x-ray amorphous material. component iron-rich silicon-poor host volatiles (water, oxygen, sulfur dioxide, carbon chlorine) detected Sample Analysis at instrument fine-grained nanophase oxide first described from soils MERs. similarity between materials...
The Mars Science Laboratory Curiosity rover has been traversing strata at the base of Aeolis Mons (informally known as Mount Sharp) since September 2014. Murray formation makes up lowest exposed Sharp group and is composed primarily finely laminated lacustrine mudstone intercalated with rare crossbedded sandstone that prodeltaic or fluvial in origin. We report on first three drilled samples from formation, measured Pahrump Hills section. Rietveld refinements FULLPAT full pattern fitting...
We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age 4.21 ± 0.35 billion years represents mixture detrital authigenic components confirms expected antiquity rocks comprising crater rim. Cosmic-ray-produced (3)He, (21)Ne, (36)Ar yield concordant surface exposure ages 78 30 million years. Surface occurred mainly present geomorphic setting rather than during primary erosion transport. Our observations are consistent with deposition shortly...
Significance Tridymite, a SiO 2 mineral that crystallizes at low pressures and high temperatures (>870 °C) from high-SiO materials, was detected concentrations in sedimentary mudstone Gale crater, Mars. Mineralogy abundance were determined by X-ray diffraction using the Chemistry instrument on Mars Science Laboratory rover Curiosity . Terrestrial tridymite is commonly associated with silicic volcanism where high-silica magmas prevail, so this occurrence first situ mineralogical evidence...
Abstract The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X‐ray diffraction (XRD) in MSL Curiosity rover. From Rietveld refinements its XRD pattern, contains following: sanidine (21% weight, ~Or 95 ); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (~25%); percent levels others including ilmenite, fluorapatite, bassanite. mass balance on Alpha Proton Spectrometer...
Clay minerals found in Gale crater, Mars, record surficial chemical weathering and changing conditions an ancient lake.
The Mars rover Curiosity in Gale crater conducted the first-ever direct chemical and mineralogical comparisons of samples that have clear parent (unaltered) daughter (altered) relationships. mineralogy chemistry within adjacent to alteration halos a sandstone formation were established by Chemistry Mineralogy (CheMin) X-ray diffraction (XRD) instrument Alpha Particle Spectrometer (APXS), respectively. Stimson sandstones unconformably overlie Murray mudstone represent youngest stratigraphic...
Research Article| November 01, 2008 Carbon isotope excursions and the oxidant budget of Ediacaran atmosphere ocean Thomas F. Bristow; Bristow * 1Department Earth Sciences, University California–Riverside, Riverside, California 92521, USA *E-mail: tbris001@student.ucr.edu Search for other works by this author on: GSW Google Scholar Martin J. Kennedy Author Article Information Publisher: Geological Society America Received: 18 Mar Revision 10 Jul Accepted: 22 First Online: 02 2017 Online ISSN:...
The Mars Science Laboratory (MSL) rover Curiosity has documented a section of fluvio-lacustrine strata at Yellowknife Bay (YKB), an embayment on the floor Gale crater, approximately 500 m east Bradbury landing site. X-ray diffraction (XRD) data and evolved gas analysis (EGA) from CheMin SAM instruments show that two powdered mudstone samples (named John Klein Cumberland) drilled Sheepbed member this succession contain up to ~20 wt% clay minerals. A trioctahedral smectite, likely ferrian...
Abstract The Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis observed rock minerals, we present results equilibrium thermochemical modeling Sheepbed mudstones Bay in order to constrain formation conditions its secondary mineral assemblage. Building on conclusions from sedimentary observations by team, assume diagenetic, situ alteration. shows that assemblage...
Analyses by the CheMin X-ray diffraction instrument on Mars Science Laboratory show that gypsum, bassanite, and anhydrite are common minerals at Gale crater. Warm conditions (~6 to 30 °C) within drive gypsum dehydration bassanite; measured surface temperatures modeled temperature depth profiles indicate near-equatorial warm-season heating can also cause bassanite. By accounting for instrumental effects we able quantify in situ abundances of Ca-sulfate phases sedimentary rocks eolian sands...
Abstract The Mars Science Laboratory rover, Curiosity, is using a comprehensive scientific payload to explore rocks and soils in Gale crater, Mars. Recent investigations of the Bagnold Dune Field provided first situ assessment an active dune on Chemistry Mineralogy (CheMin) X‐ray diffraction instrument Curiosity performed quantitative mineralogical analyses <150 μm size fraction Namib at location called Gobabeb. Gobabeb dominated by basaltic minerals. Plagioclase, Fo56 olivine, two...
Abstract Vera Rubin ridge (VRR) is an erosion‐resistant feature on the northwestern slope of Mount Sharp in Gale crater, Mars, and orbital visible/shortwave infrared measurements indicate it contains red hematite. The Mars Science Laboratory Curiosity rover performed extensive campaign VRR to study its mineralogy, geochemistry, sedimentology determine depositional diagenetic history constrain processes by which hematite could have formed. X‐ray diffraction (XRD) data from CheMin instrument...
Crystal chemical algorithms were used to estimate the composition of selected mineral phases observed with CheMin X-ray diffractometer onboard NASA Curiosity rover in Gale crater, Mars. The sampled materials include two wind-blown soils, Rocknest and Gobabeb, six mudstones Yellowknife Bay formation (John Klein Cumberland) Murray (Confidence Hills, Mojave2, Telegraph Peak), as well five sandstones, Windjana samples unaltered Stimson (Big Sky Okoruso) altered (Greenhorn Lubango). major...
Modified clay minerals on Mars Sedimentary rocks exposed in Gale crater contain extensive minerals. Bristow et al. analyzed drill samples collected by the Curiosity rover as it climbed up sedimentary layers crater. They found evidence of past reactions with liquid water and sulfate brines, which could have percolated through from an overlying deposit. Similar deposits are widespread across planet represent some last to form before lost its surface water, so results inform our understanding...
Abstract The Glen Torridon (GT) region in Gale crater, Mars is a with strong clay mineral signatures inferred from orbital spectroscopy. CheMin X‐ray diffraction (XRD) instrument onboard the Science Laboratory rover, Curiosity , measured some of highest abundances to date within GT, complementing detections. GT may also be unique because XRD patterns samples, identified new phases, including: (a) Fe‐carbonates, and (b) phase novel peak at 9.2 Å. Fe‐carbonates have been previously suggested...
The Mars Science Laboratory rover, Curiosity, explored the clay mineral-bearing Glen Torridon region for 1 Martian year between January 2019 and 2021, including a short campaign onto Greenheugh pediment. sought to characterize geology of area, seek evidence habitable environments, document onset potentially global climatic transition during Hesperian era. Curiosity roved 5 km in total throughout Torridon, from Vera Rubin ridge northern margin acquired samples 11 drill holes this conducted...
Abstract For the first time on Mars, crystalline magnesium‐sulfate mineral starkeyite (MgSO 4 ‧4H 2 O) was definitively identified using CheMin X‐ray diffraction instrument at Gale crater. At Canaima drill site, along with amorphous MgSO ‧ n H O are among “polyhydrated Mg‐sulfates” interpreted in orbital reflectance spectra. Mg‐sulfates good climate indicators as they very responsive to changes temperature and relative humidity. We hypothesize that, through evaporation, formed end of brine...
Assemblages of clay minerals are routinely used as proxies for paleoclimatic change and paleoenvironmental conditions in Phanerozoic rocks. However, this tool is rarely applied older sedimentary units. In paper, the mineralogy Doushantuo Formation South China documented, providing constraints on depositional Ediacaran Yangtze platform that host earliest animal fossils geological record. multiple sections from Gorges area, trioctahedral smectite (saponite) its diagenetic products (mixed-layer...
Ferrian saponite from the eastern Santa Monica Mountain, near Griffith Park (Los Angeles, California), was investigated as a mineralogical analog to smectites discovered on Mars by CheMin X-ray diffraction instrument onboard Science Laboratory (MSL) rover. The martian clay minerals occur in sediment of basaltic composition and have 02l bands peaking at 4.59 Å, consistent with tri-octahedral smectites. occurs basalts pseudomorphs after olivine mesostasis glass fillings vesicles cracks has...