A5079734064- Paleontology and Stratigraphy of Fossils
- Geochemistry and Elemental Analysis
- Radioactive element chemistry and processing
- Geology and Paleoclimatology Research
- Geological and Geochemical Analysis
- Isotope Analysis in Ecology
- Radioactive contamination and transfer
- Astro and Planetary Science
- Methane Hydrates and Related Phenomena
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Geologic Mapping
- Marine and environmental studies
- Marine and coastal ecosystems
- Planetary Science and Exploration
- Ocean Acidification Effects and Responses
- Marine Biology and Ecology Research
- Geological and Geophysical Studies
- Bone health and osteoporosis research
- Nuclear Physics and Applications
- Groundwater and Isotope Geochemistry
- Atmospheric and Environmental Gas Dynamics
- Heavy metals in environment
- Microbial Community Ecology and Physiology
- Water Quality Monitoring and Analysis
- Geological Studies and Exploration
Vesta Sciences (United States)
2023-2024
Arizona State University
2014-2023
University of Tennessee at Knoxville
2019-2023
University of Antwerp
2023
National High Magnetic Field Laboratory
2021
Florida State University
2021
Tempe Union High School District
2015
Cornell University
2010
Explaining the ~5-million-year delay in marine biotic recovery following latest Permian mass extinction, largest crisis of Phanerozoic, is a fundamental challenge for both geological and biological sciences. Ocean redox perturbations may have played critical role this delayed recovery. However, lack quantitative constraints on details Early Triassic oceanic anoxia (for example, time, duration, extent) leaves links between conditions ambiguous. We report high-resolution U-isotope (δ238U) data...
The terminal Ediacaran Period witnessed the decline of Ediacara biota (which may have included many stem-group animals). To test whether oceanic anoxia might played a role in this evolutionary event, we measured U isotope compositions (δ238U) sedimentary carbonates from Dengying Formation South China to obtain new constraints on extent global redox change during Ediacaran. We found most negative carbonate δ238U values yet reported (-0.95 per mil), which were reproduced two widely spaced...
Significance Throughout Earth’s history, redox transformations in sedimentary environments have occurred through chemical processes (abiotic pathways) or via the activity of living microorganisms (biotic pathway). Tools able to discriminate between these two mechanisms are major interest, as they would contribute significantly understanding biogeochemical events that shaped evolution life on our planet. Here, we show there is a clear difference isotopic signature associated with abiotic and...
The ability to rapidly detect changes in bone mineral balance (BMB) would be of great value the early diagnosis and evaluation therapies for metabolic diseases such as osteoporosis some cancers. However, measurements BMB are hampered by difficulties with using biochemical markers quantify relative rates resorption formation need wait months years altered produce density large enough resolve X-ray densitometry. We show here that, humans, natural abundances Ca isotopes urine change response...
Abstract Uranium isotopes (238U/235U) in carbonates, a proxy for global-ocean redox conditions owing to their sensitivity and long residence time seawater, exhibit substantial variability the Daxiakou section of south China from upper-middle Permian through mid-lower Triassic (∼9 m.y.). Middle late ocean were similar that modern characterized by improving oxygenation ∼2 m.y. prior latest mass extinction (LPME), countering earlier interpretations sustained or gradually expanding anoxia during...
Research Article| February 09, 2018 Congruent Permian-Triassic δ238U records at Panthalassic and Tethyan sites: Confirmation of global-oceanic anoxia validation the U-isotope paleoredox proxy Feifei Zhang; Zhang * 1School Earth & Space Exploration, Arizona State University, Tempe, 85287, USA *E-mail: fzhang48@asu.edu; zhff414@hotmail.com Search for other works by this author on: GSW Google Scholar Thomas J. Algeo; Algeo 2Department Geology, University Cincinnati, Ohio 45221, USA3State Key...
Demonstration of a commercially-available, fully-automated, offline chromatography method capable simultaneously purifying both Ca and Sr for stable radiogenic isotope analysis.
The role of O2 in the evolution early animals, as represented by some members Ediacara biota, has been heavily debated because current geochemical evidence paints a conflicting picture regarding global marine levels during key intervals rise and fall biota. Fossil indicates that diversification biota occurred or shortly after Ediacaran Shuram negative C-isotope Excursion (SE), which is often interpreted to reflect ocean oxygenation. However, there oxygen SE middle Period. To help resolve...
Research Article| August 04, 2017 Uranium and carbon isotopes document global-ocean redox-productivity relationships linked to cooling during the Frasnian-Famennian mass extinction Huyue Song; Song * 1State Key Laboratory of Biogeology Environmental Geology, China University Geosciences, Wuhan 430074, *E-mails: hysong@cug.edu.cn; thomas.algeo@uc.edu Search for other works by this author on: GSW Google Scholar Haijun Thomas J. Algeo; Algeo China2Department Cincinnati, Ohio 45221, USA3State...