A5070838720- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- Electron and X-Ray Spectroscopy Techniques
- Hydrocarbon exploration and reservoir analysis
- Geological Studies and Exploration
- X-ray Spectroscopy and Fluorescence Analysis
- earthquake and tectonic studies
- Geochemistry and Geologic Mapping
- Mineralogy and Gemology Studies
- Methane Hydrates and Related Phenomena
- Advanced Materials Characterization Techniques
- Glass properties and applications
- Ion-surface interactions and analysis
- Paleontology and Stratigraphy of Fossils
- Seismic Imaging and Inversion Techniques
- Analytical chemistry methods development
- Plasma Diagnostics and Applications
- High-Temperature Coating Behaviors
- Iron oxide chemistry and applications
- Geological formations and processes
- Metal Extraction and Bioleaching
- Nuclear materials and radiation effects
- Reservoir Engineering and Simulation Methods
- Geochemistry and Elemental Analysis
- Geological and Geophysical Studies
University of British Columbia
2023-2024
University of Minnesota
2014-2023
University of Minnesota System
2014-2023
Twin Cities Orthopedics
2020
University of Freiburg
2011-2013
Max Planck Institute for Chemistry
2008-2011
University of Hawaii System
2008-2011
Max Planck Society
2006
[1] Expeditions 304 and 305 of the Integrated Ocean Drilling Program cored logged a 1.4 km section domal core Atlantis Massif. Postdrilling research results summarized here constrain structure lithology Central Dome this oceanic complex. The dominantly gabbroic sequence recovered contrasts with predrilling predictions; application ground truth in subsequent geophysical processing has produced self-consistent models for Dome. presence many thin interfingered petrologic units indicates that...
Abstract This work advances the understanding of influence rare earth (RE) ion radius on stability and extent garnet solid solution phase in (ytterbia/yttria/gadolinia)‐calcia‐magnesia‐alumina‐silica systems. Guided by crystal chemistry charge neutrality constraints, selected compositions notional field were synthesized, equilibrated at 1400°C, characterized to determine equilibrium phases their compositions. The results show a significant reduction silicate relative apatite with increasing...
Several ODP-IODP expeditions drilled oceanic core complexes (OCCs) interpreted as exhumed portions of lower crust close to the ridge axis, and provide community with invaluable sampling opportunity for further constraining magmatic processes involved in formation slow-spreading crust. ODP Hole 735B presents most primitive lithologies sampled at Atlantis Bank OCC (Southwest Indian Ridge) a ~250 m thick section that was previously single crustal intrusion. We combined detailed structural...
Abstract While much progress has been made in electron-probe microanalysis (EPMA) to improve the accuracy of point analysis, same level attention not always applied quantification wavelength-dispersive spectrometry (WDS) X-ray intensity maps at individual pixel level. We demonstrate that rigor traditional analysis can also be pixels maps, along with additional acquisition and quantitative processing procedures further accuracy, precision, mapping throughput. Accordingly, map should include...
A quantitative understanding of nitrogen incorporation in Earth materials is important for constraining volatile evolution planetary bodies. We used a combination chemical (SIMS, EPMA, and laser-extraction mass spectrometry) spectroscopic (FTIR) observations to study contents speciation mechanisms silicate glasses, metal alloys, an N-bearing mineral (hyalophane). One suite Fe-free basaltic glasses was studied by all four methods. Concentrations N these determined EPMA are systematically...
Abstract In orogens worldwide and throughout geologic time, large volumes of deep continental crust have been exhumed in domal structures. Extension‐driven ascent bodies deep, hot is a very efficient mechanism for rapid heat mass transfer from to shallow crustal levels therefore an important the evolution continents. The dominant rock type domes quartzofeldspathic gneiss (typically migmatitic) that does not record its former high‐pressure (HP) conditions equilibrium mineral assemblage;...
Pyroxenites are an essential component in petrological and geochemical models for melt formation at mid-ocean ridges ocean islands. Despite their rarity, origin has been widely discussed various processes have invoked formation. Here, we present a detailed study of the microtextures major, minor trace element compositions relatively fresh pyroxenites associated harzburgites from ultraslow-spreading Lena Trough, Arctic Ocean. Microtextural characteristics suggest by magmatic...
Passive rifting and the early non-volcanic formation of ocean basins are fundamental aspects plate tectonic cycle.Cenozoic margins where this has occurred rare.Here we present new observations from Lena Trough in Arctic Ocean that bear on phase oceanic spreading such rifts.Lena is an oblique seafloor rift system bounding North American Eurasian plates, connecting neighboring Gakkel Ridge with rest global mid-ocean ridge system.Mapping sampling show widespread mantle outcrop along two...
To evaluate the accuracy of Fe3+ and Fe2+ ratios in silicate glasses determined by Mössbauer spectroscopy, we examine detail temperature (47-293 K) spectra for two andesitic glasses, one quenched at 1 atm, 1400 °C (VF3) other 3.5 GPa, 1600 (M544). Variabletemperature these are used to characterize recoilless fraction, f, different methods-a relative method (RM) based on dependence doublets second center shift (CS) doublets. The ratio fractions Fe2+, CT, can then be adjust observed area into...
Journal Article Quantitative EPMA of Nitrogen in Silicate Glasses Get access Anette von der Handt, Handt University Minnesota, Dept. Earth Sciences, Minneapolis (USA) Search for other works by this author on: Oxford Academic Google Scholar Celia Dalou Microscopy and Microanalysis, Volume 22, Issue S3, 1 July 2016, Pages 1810–1811, https://doi.org/10.1017/S1431927616009892 Published: 25 2016
Abstract The recent availability of Schottky-type field emission electron microprobes provides incentive to consider analyzing micrometer-sized features. Yet, quantify sub-micrometer-sized features, the interaction volume must be reduced by decreasing accelerating voltage. However, K lines transition elements (e.g., Fe) then cannot excited, and L used. Fe α 1,2 line is most intense series but bonding effects change its atomic parameters because it involves a valence band transition. For...