A5011404921- Paleontology and Stratigraphy of Fossils
- Geomagnetism and Paleomagnetism Studies
- Geological and Geochemical Analysis
- Geological Studies and Exploration
- Astro and Planetary Science
- Geology and Paleoclimatology Research
- Planetary Science and Exploration
- Methane Hydrates and Related Phenomena
- Historical and Architectural Studies
- Geological and Geophysical Studies
- Geochemistry and Elemental Analysis
- Geochemistry and Geologic Mapping
- Microbial Community Ecology and Physiology
- Genetics, Bioinformatics, and Biomedical Research
- Space Science and Extraterrestrial Life
- Winter Sports Injuries and Performance
- Spaceflight effects on biology
- Biotechnology and Related Fields
- Historical Astronomy and Related Studies
- Genomics and Phylogenetic Studies
- Archaeology and ancient environmental studies
- Cryospheric studies and observations
- Mineralogy and Gemology Studies
- Silicon Effects in Agriculture
Texas A&M University
2023-2024
University of Colorado Boulder
2020-2024
University of Colorado System
2022-2023
Mitchell Institute
2022
Abstract The Mars 2020 Perseverance rover has examined and sampled sulfate‐rich clastic rocks from the Hogwallow Flats member at Hawksbill Gap Yori Pass Cape Nukshak. Both strata are located on Jezero crater western fan front, lithologically stratigraphically similar, have been assigned to Shenandoah formation. In situ analyses demonstrate that these fine‐grained sandstones composed of phyllosilicates, hematite, Ca‐sulfates, Fe‐Mg‐sulfates, ferric sulfates, possibly chloride salts. Sulfate...
Abstract The Perseverance rover has collected seven oriented samples of sedimentary rocks, all likely older than the oldest signs widespread life on Earth, at exposed base western fan in Jezero crater, Mars. include a sulfate‐ and clay‐bearing mudstone sandstone, fluvial sandstone from stratigraphically low position front, carbonate‐bearing deposited above sulfate‐bearing strata. All contain aqueously precipitated materials most or were deposited. Although instruments have not confidently...
Abstract Recovering ancient records of Earth's magnetic field is essential for determining the role magnetosphere in protecting early Earth from cosmic radiation and atmospheric escape. We present paleomagnetic tests hinting that a record 3.7‐billion‐year (Ga) old may be preserved northeastern Isua Supracrustal Belt as chemical remanent magnetization acquired during amphibolite‐grade metamorphism banded iron formation. Multiple petrological geochronological lines evidence indicate...
Abstract Biogeochemical cycling of sulfur is relatively understudied in terrestrial environments compared to marine environments. However, the comparative ease access, observation, and sampling settings can expand our understanding organisms processes important modern cycle. Furthermore, these sites may allow for discovery useful process analogs ancient sulfur‐metabolizing microbial communities at times Earth's past when atmospheric O 2 concentrations were lower sulfide was more prevalent...
Abstract The Mars 2020 Perseverance rover discovered fine‐grained clastic sedimentary rocks in the “Hogwallow Flats” member of “Shenandoah” formation at Jezero crater, Mars. Hogwallow Flats shows evidence multiple phases diagenesis including Fe/Mg‐sulfate‐rich (20–30 wt. %) outcrop transitioning downward into red‐purple‐gray mottled outcrop, Fe/Mg clay minerals and oxides, putative concretions, occasional Ca sulfate‐filled fractures, variable redox state over small (cm) spatial scales. This...
We present paleomagnetic field tests that hint a record of Earth’s 3.7-billion-year (Ga) old magnetic may be preserved as chemical remanent magnetization acquired during amphibolite-grade metamorphism in the banded iron formation from northeastern Isua Supracrustal Belt. Multiple petrological and geochronological lines evidence indicate northern most part has not experienced metamorphic temperatures exceeding 350◦C since Eoarchean, suggesting rocks have been significantly heated was...
Earth is the only known inhabited world in our solar system. Criteria essential for planetary habitability include surface liquid water, a stable atmosphere, and magnetic field. While rock record suggests has fulfilled these criteria at least 4 billion years (Ga), both its environment life have evolved over time. The Great Oxygenation Event (GOE), which occurred ~2.5 Ga ago, drastically altered chemistry of oceans atmosphere. Decoding environmental signals recorded rocks prior to GOE...
<p>The biogenicity of proposed stromatolites from deformed greenschist/amphibolite facies Eoarchean (ca. 3.71 Ga) rocks the Isua Supracrustal Belt (ISB) in West Greenland, is debated  [1,2; cf. 3]. To assess their promise as primary sedimentary structures – opposed to artefacts strain localization layered ductile we report new field mapping at discovery site Nutman et al. (2016) guide micro- and macro-structural investigations geochemical sampling....
<p>The biogenicity of proposed stromatolite structures from Eoarchean (ca. 3.71 Ga) rocks the Isua Supracrustal Belt (ISB) in West Greenland is under debate. Our 2020 publication argues against for stromatolites. The subsequent Comment to our work challenged some fundamental arguments a tectonic origin structures. This has been an opportunity us elaborate on these and further refine solidify initial conclusion that they represent expected outcome deformation displayed ISB....