A5101908197- Geological and Geochemical Analysis
- Astro and Planetary Science
- Paleontology and Stratigraphy of Fossils
- Geochemistry and Geologic Mapping
- Isotope Analysis in Ecology
- High-pressure geophysics and materials
- Geology and Paleoclimatology Research
- earthquake and tectonic studies
- Forensic Anthropology and Bioarchaeology Studies
- Geochemistry and Elemental Analysis
- Marine animal studies overview
- Pacific and Southeast Asian Studies
- Planetary Science and Exploration
- Pleistocene-Era Hominins and Archaeology
- Silicon Effects in Agriculture
- Groundwater and Isotope Geochemistry
- Nuclear Physics and Applications
- Geological formations and processes
- Spacecraft and Cryogenic Technologies
- Stellar, planetary, and galactic studies
- Evolution and Paleontology Studies
- Astrophysics and Star Formation Studies
- Mineralogy and Gemology Studies
- Primate Behavior and Ecology
- Bone and Dental Protein Studies
Australian National University
2014-2024
Griffith University
2021-2024
The University of Queensland
2022-2024
Environmental Earth Sciences
2022-2023
La Jolla Alcohol Research
2004-2014
Heidelberg University
2013-2014
Institute for Research in Biomedicine
2014
Massachusetts Institute of Technology
2014
Institute of Bioorganic Chemistry
2013
Lomonosov Moscow State University
2013
The Great Oxidation Event (GOE) has been defined as the time interval when sufficient atmospheric oxygen accumulated to prevent generation and preservation of mass-independent fractionation sulphur isotopes (MIF-S) in sedimentary rocks. Existing correlations suggest that GOE was rapid globally synchronous. Here we apply isotope analysis diagenetic sulphides combined with U-Pb Re-Os geochronology document cycle evolution Western Australia spanning GOE. Our data indicate that, from ~2.45 Gyr...
We determined interstellar cosmic ray exposure ages of 40 large presolar silicon carbide grains extracted from the Murchison CM2 meteorite. Our ages, based on cosmogenic Ne-21, range 3.9 ± 1.6 Ma to ∼3 2 Ga before start Solar System ∼4.6 ago. A majority have lifetimes <300 Ma, which is shorter than theoretical estimates for grains. These condensed in outflows asymptotic giant branch stars <4.9 ago that possibly formed during an episode enhanced star formation ∼7 minority >1 Ga. Longer are...
The LA-MC-ICP-MS method applied to U-Pb in situ dating is still rapidly evolving due improvements both lasers and ICP-MS. To test the validity reproducibility of method, 5 different zircon samples, including standard Temora-2, ranging age between 2.2 Ga 246 Ma, were dated using SHRIMP. selected zircons by SHRIMP and, after gentle polishing, laser spot was driven same site or on phase with a 213 nm microprobe coupled multi-collector mixed system. data collected routine size 25 μm some cases,...
In 2013 we presented a model for identifying nursing behavior from primate teeth based on rapid postnatal concentration changes in the non-essential trace element barium. Here leverage permanent neonatal (birth) line enamel of several dozen M1 cusps to compare pre- and trends barium, zinc, strontium, oxygen, as each is believed evince developmental patterning. Barium zinc are most consistent biomarkers initiation; majority shows increases prenatal enamel, whereas strontium decreases or no...
Analytical protocols for SHRIMP‐SI oxygen isotope analysis (δ 18 O) of a suite zircon reference materials (RMs) are presented. Data reduction involved robust estimate uncertainties associated with the individual spot as well groups where data combined. The repeatability δ O measurements is dependent on both analytical conditions and choice primary material. Under optimised conditions, was often better than 0.4‰ (2 s ) allowing sample to be obtained 0.2‰ (at 95% confidence limit). Single...
Variability in resource availability is hypothesized to be a significant driver of primate adaptation and evolution, but most paleoclimate proxies cannot recover environmental seasonality on the scale an individual lifespan. Oxygen isotope compositions (δ 18 O values) sampled at high spatial resolution dentitions modern African primates ( n = 2,352 near weekly measurements from 26 teeth) track concurrent seasonal precipitation, regional climatic patterns, discrete meteorological events,...
Abstract Redox-sensitive trace elements and sulfur isotope compositions obtained via in situ analyses of sedimentary pyrites from marine black shales are used to track atmosphere-ocean redox conditions between ∼1730 ∼1360 Ma the McArthur Basin, northern Australia. Three shale formations within basin (Wollogorang Formation 1730 ± 3 Ma, Barney Creek 1640 Upper Velkerri 1361 21 Ma) display systematic stratigraphic variations pyrite trace-element using LA-ICP-MS. The concentrations several their...
Research Article| September 01, 2006 Combined stratigraphic and isotopic studies of Triassic strata, Cuyo Basin, Argentine Precordillera J. N. Ávila; Ávila 1Laboratório de Geologia Isotópica, Instituto Geociências, Universidade Federal do Rio Grande Sul, Porto Alegre, RS 91501–970, Brazil Search for other works by this author on: GSW Google Scholar F. Chemale, Jr.; Jr. G. Mallmann; Mallmann K. Kawashita; Kawashita R. A. Armstrong 2Research School Earth Sciences, Australian National...
We report the first tungsten isotopic measurements in stardust silicon carbide (SiC) grains recovered from Murchison carbonaceous chondrite. The isotopes 182W, 183W, 184W, 186W and 179Hf, 180Hf were measured on both an aggregate (KJB fraction) single SiC (LS+LU believed to have condensed outflows of low-mass carbon-rich asymptotic giant branch (AGB) stars with close-to-solar metallicity. shows small deviations terrestrial (=solar) composition 182W/184W 183W/184W ratios, deficits 182W 183W...
The time span between the formation of presolar grains in stellar outflows and their incorporation into early solar-system solids is poorly constrained. Knowledge this essential for a better understanding processing interstellar medium (ISM) processes solar system. Here, we report residence times ∼3–1100 Myr large (∼5–50 μm) SiC grains, based on content He Ne produced by Galactic cosmic rays. A majority these have order few tens up to less than 200 Myr, considerably shorter theoretical...
A wide number of genetic models have been proposed for volcanically transported ruby and sapphire deposits around the world. In this contribution we compare trace element chemistry, mineral melt inclusions, oxygen isotope ratios in blue to reddish-violet sapphires from Yogo Gulch, Montana, U.S.A., with rubies Chantaburi-Trat region Thailand Pailin Cambodia. The similarities between Thai/Cambodian suggest a common origin gem corundum both deposits. Specifically, advance model whereby formed...
Variations in human subsistence and settlement patterns have been documented at Holocene archaeological sites across Island Mainland Southeast Asia. Although climate is frequently invoked as a causal mechanism underlying this variation, direct evidence of ancient rainfall variability on the scale lifetimes has thus far elusive. Here we use novel time-resolute method for situ measurement tooth enamel δ18O values (n = 2629 near-weekly measurements sampling 51 years) to assess past seasonality...
Studies of climate variation commonly rely on chemical and isotopic changes recorded in sequentially produced growth layers, such as corals, shells, tree rings, well accretionary deposits—ice sediment cores, speleothems. Oxygen compositions (δ 18 O) tooth enamel are a direct method reconstructing environmental experienced by an individual animal. Here, we utilize long-forming orangutan dentitions ( Pongo spp.) to probe recent ancient rainfall trends weekly basis over ~3–11 years per...
Individual mainstream stardust silicon carbide (SiC) grains and a SiC-enriched bulk sample from the Murchison carbonaceous meteorite have been analyzed by Sensitive High Resolution Ion Microprobe - Reverse Geometry (SHRIMP-RG) for Eu isotopes. The are believed to condensed in outflows of 1.5 3 Msun carbon-rich asymptotic giant branch (AGB) stars with close-to-solar metallicity. 151Eu fractions [fr(151Eu) = 151Eu/(151Eu+153Eu)] derived our measurements compared previous astronomical...