A5058106939- Geological and Geochemical Analysis
- earthquake and tectonic studies
- High-pressure geophysics and materials
- Geochemistry and Geologic Mapping
- Hydrocarbon exploration and reservoir analysis
- Drilling and Well Engineering
- Seismic Imaging and Inversion Techniques
- Geotechnical and Geomechanical Engineering
- Mineralogy and Gemology Studies
- Geological Studies and Exploration
- Rock Mechanics and Modeling
- Paleontology and Stratigraphy of Fossils
- Geology and Paleoclimatology Research
- Geological and Geophysical Studies
- Geomagnetism and Paleomagnetism Studies
- CO2 Sequestration and Geologic Interactions
- Methane Hydrates and Related Phenomena
- Clay minerals and soil interactions
- Geochemistry and Elemental Analysis
- Mineral Processing and Grinding
- Seismic Waves and Analysis
- Geological Modeling and Analysis
- Hydraulic Fracturing and Reservoir Analysis
- Astro and Planetary Science
- Work-Family Balance Challenges
University of Delaware
2016-2024
Child Trends
2023
Centers for Medicare and Medicaid Services
2023
Arizona State University
2022
University of Georgia
2020
Florida Department of State
2019
Boston College
2019
Boise State University
2019
University of Rhode Island
2019
Stanford University
2012-2017
Abyssal peridotites are ultramafic rocks collected from mid-ocean ridges that the residues of adiabatic decompression melting. Their compositions provide information on degree melting and melt–rock interaction involved in formation oceanic lithosphere, as well providing constraints pre-existing mantle heterogeneities. This review presents a compilation abyssal peridotite geochemical data (modes, mineral major elements, clinopyroxene trace elements) for > 1200 samples 53 localities 6 ridge...
Abyssal peridotites, the depleted solid residues of ocean ridge melting, are most direct samples available to assess upper oceanic mantle composition. We present detailed isotope and trace element analyses pyroxene mineral separates from Southwest Indian Ridge abyssal peridotites pyroxenites in order constrain size length scale heterogeneity. Our results demonstrate that can be highly heterogeneous <1 km even <0.1 m scales. Examination Nd isotopes relation modal, trace, major...
Kane Megamullion, an oceanic core complex near the Mid-Atlantic Ridge (MAR) abutting Transform, exposes nearly full plutonic foundation of MARK paleo-ridge segment. This provides first opportunity for a detailed look at patterns mantle melting, melt transport and delivery slow-spreading ridge. The lower crust section is heterogeneous, as result focused flow to different points beneath ridge segment in time space, over ∼300–400 kyr scale. association residual peridotite, dunite troctolite...
Abstract The concentration and distribution of volatiles in the Earth's mantle influence properties such as melting temperature, conductivity, viscosity. To constrain upper water content, concentrations H 2 O, P, F were measured olivine, orthopyroxene, clinopyroxene peridotites by secondary ion mass spectrometry. Analyzed are xenoliths (Pali Aike, Spitsbergen, Samoa), orogenic (Josephine Peridotite), abyssal (Gakkel Ridge, Southwest Indian Tonga Trench). comparison fresh altered demonstrates...
We conducted a microstructural study of high-strain mantle shear zone from the Josephine Peridotite, SW Oregon, USA. The goal this is to understand how evolution at large strains leads transitions in rheological behavior. we investigated exhibits higher strain and greater localization than previously studied zones Peridotite. margins have homogeneous microstructure, characterized by moderately strong olivine fabrics, fairly weak orthopyroxene grain sizes 2–3 mm. highly deformed samples...
Ranges in clinopyroxene trace element contents of 2–3 orders magnitude occur over <2 cm distance peridotite samples from the Atlantis II Fracture Zone on Southwest Indian Ridge. This represents smallest length-scale at which concentrations have been observed to vary abyssal peridotites. Because absence any accompanying veins or other macroscopic features melt–rock interaction, these peridotites are interpreted as being result cryptic metasomatism by a low-volume melt. The small variations,...
Mantle sulfides (Fe–Ni–Cu-rich base metal or BMS; Fig. 1) play a crucial role in the distribution of Re, Os, and Pb mantle rocks are thus fundamental to obtaining absolute ages by direct geochronology using Re–Os Pb–Pb isotope systems on samples. samples exist as hundreds exposures peridotites, pyroxenites diamonds, either brought surface accidental xenoliths xenocrysts during kimberlitic alkali basaltic volcanism (for comprehensive reviews, see Pearson et al. 2014; Aulbach 2016, this...
The elevated oxygen fugacity recorded by subduction-related lavas and peridotites, relative to their mid-ocean ridge counterparts, fundamentally influences the petrogenesis of arc magmas. However, timing, process, spatial extent oxidizing mass transfer at subduction zones remain unknown. Forearc which are sometimes exposed on trench wall overriding plate, record chemical fingerprints melting melt–rock interaction processes that occur during following initiation, thus provide insight into...
Natural peridotite samples containing olivine, orthopyroxene, and spinel can be used to assess the oxygen fugacity (fO2) of upper mantle. The calculation requires accurate precise quantification Fe3+/∑Fe ratios. Wood Virgo (1989) presented a correction procedure for electron microprobe (EPMA) measurements ratios that relies on reported correlation between difference in ratio by Mössbauer spectroscopy (ΔFe3+/∑FeMöss-EPMA) Cr# [Cr/(Al+Cr)] spinel. This has not been universally adopted, part,...
When deforming by low-temperature plasticity, the strength of mantle mineral olivine is controlled its grain size.
Abstract The influence of pyroxene on upper mantle viscosity remains unclear but may occur either through its difference in strength relative to olivine or effect microstructure. To determine the role moderating peridotite viscosity, we analyzed microstructures paired harzburgites and dunites from a natural shear zone exposed Josephine Peridotite. Olivine crystallographic textures evolve similarly with increasing strain, indicating operation similar deformation mechanisms olivine. mean grain...
This cohort study assesses outcomes of patients treated during the initial 16 months Centers for Medicare & Medicaid Services Acute Hospital Care at Home initiative.
Ultraslow spreading at mid-ocean ridges limits melting due to on-axis conductive cooling, leading the prediction that peridotites from these are relatively fertile. To test this, we examined abyssal Gakkel Ridge, slowest ridge in global ocean system. Major and trace element concentrations pyroxene olivine minerals reported for 14 dredged peridotite samples Sparsely Magmatic (SMZ) Eastern Volcanic (EVZ) Zones. We observe large compositional variations among same dredge dredges close proximity...
Abstract Uncertainty in constitutive equations for brittle‐ductile deformation limits our understanding of earthquake nucleation and propagation at the base seismogenic lithosphere. To reduce this uncertainty, we investigate exhumed strike‐slip faults related features Lake Edison granodiorite (central Sierra Nevada, CA) that developed 250–500°C ~250 MPa. The Seven Gables outcrop contains a 10 cm wide contractional fault step separating 2 m‐scale left‐lateral faults. Within step, an ~ 4 thick...
The Southwest Indian Ridge (SWIR) at 9–16°E and 52–53°S is characterized by ultra-slow, oblique spreading contains one of the few documented occurrences pyroxenite veins associated with abyssal peridotites. origin these uncommon lithologies still debated. We present a detailed study (including electron microprobe laser ablation inductively coupled plasma mass spectrometry) spinel websterites collected during Cruise 162, Leg 9, R.V. Knorr. Rare earth element patterns in clinopyroxenes (Cpx)...