Current Research Updates, Projects, and interests
See Research Gate profile or GoogleScholar page
I will be editing “Reviews and Mineralogy and Geochemistry” MSA Volume (2020) “Triple Oxygen Isotopes on Earth” with Andreas Pack. Short course will be held at AGU 2020 in San Francisco. I myself will write a Chapter on triple oxygen isotopes in shales through time
Our currently funded research topics include:
1) Triple oxygen isotope investigation of shales, clays and hydrothermally altered rocks cross the geologic history which builds on our recent analytical developments. (students David Zakharov, Research Associate Jim Palandri, many collaborators), new NSF grant
new students are welcome to apply
2) -Volcanic ash and glass as paleoenvironmental isotopic climate tool using D/H and oxygen isotopes (student Mike Hudak, past students Angela Seligman and Gary Nolan, collaborator and former postdoc Erwan Martin), continuing NSF grant
3) Continuing research on the origin of large volume silicic magmas using isotopic microanalytical tools (especially zircons) and numerical modeling. We concentrate on the Yellowstone hot spot track centers, Iceland and Kamchatka. Past CAREER NSF grant, current funds, international collaboration with Russia and Switzerland.
In 2010-2016:
-Ultra-low-d18O and dD rocks from Karelia, Russia as recorders (or proof) of the first pan global glaciation after which oxygen increased in the atmosphere 2.4 billion years ago. We have the world lowest d18O (-27.3‰ SMOW) rocks
-Mass-independent signatures of volcanic sulfate with its connections to the ozone layer depletion after large and small volcanic eruptions.
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My traditional interests are in the fields of Volcanology, high-temperature Geochemistry but current interests and efforts are shifting more toward the the cutting edge research involving triple oxygen isotopes, with applications mostly in the “low-temperature” geochemistry fields. For example, we are using shales and clays to talk about climate and evolutions of weathering conditions on the surface, the crust, and hydrosphere. We are also using volcanic glass as recorder of paleoenvironmental conditions. See titles of papers under Publications to get the sense of current our efforts.
Our Earth Science Department is particularly great for volcanology, and we have a recently created Volcanology cluster with many faculty and students who are interested in various aspects of volcano behavior.
Oxygen isotopes are important because oxygen is the major component of many minerals, rocks, and fluids. Each of these have different isotopic values which are controlled by the sources of drivation, thermodynamics of isotope fractionation, and by the kinetics of isotope exchange. Laser fluorination and ion microprobes, two instruments of my expertise, serve as excellent tools to unravel these phenomena in nature and interpret the variations. High precision is critical in volcanology, igneous petrology, and mantle and crustal geochemistry, simply because at high temperatures isotopic fractionations are small, and so the requirements for precision are very demanding.
I collaborate with scientists in Switzerland on zircon U-Pb dating and other aspects of zircon research. I spent two of my sabbaticals in Switzerland.
I collaborate with scientists in Russia on numerical modeling of magmatic processes. We are trying to bring together isotope geochemistry and numerical models to better understand the nature of the processes
Lab equipment and analytical developments
We have:MAT253 multi-collector mass spec, laser fluorination line for extraction of oxygen from silicates, with recently added triple oxygen gas chromatographic system. A Newave 30W laser-motion system is used in our extraction and is the chief method used to react minerals in the sample chamber. Line includes VCR joints with Ni gaskets, all-metal electropolished tubing, high-flow diaphragm-valves, and small line size. The line permits 4 oxygen extractions per hour for routine operation and 5-6 triple oxygen analyses per day. We will be working on automating some operations.
TC/EA system is used to extract waters from solid materials such as micas and amphiboles and liquids (such as waters or solutions) to study hydrogen is oxygen isotopes. This is accomplished in a continuous flow mode, which means that small amount of gas is carried in a helium flow.
GasBench II device, another continuous flow peripheral device, is now used for routine carbonate analysis for carbon and oxygen isotopes in automated mode, water analysis, dissolved inorganic carbon analysis. The PAL autosampler, a robotic arm, is capable of sample introduction into the GasBench and TC/EA.
General purpose vacuum line is used for off-line sample preparation, such as evacuation of quartz sample tubes with organic matter in them in preparation for combustion in oven using cupric oxide in order to study carbon isotopic composition of organic compounds. It can be used for off-line carbonate reaction with orthophosphoric acid for precise dual-inlet measurements. It has a series of metal and glass vacuum manifolds, isolated volumes, gauges and electronic manometers, diffusion and a rotary vane pumps.
We also have Sartorius six-digit balance capable of weighing small samples with ±1 microgram precision, Nikkon stereoscope with 0.8-8 zoom ratio, old robust German petrographic microscope, digital water heating temperature-control bath, Bransonic ultrasound cleaners, and other smaller pieces of equipment.
With these pieces of equipment we are the newly established stable isotope lab with many capabilities
Press Releases about our research
To new graduate students and postdocs: I suggest being knowledgeable in geology, math, inorganic chemistry and have interest in lab and field work.
UO is competitive (~20% acceptance) we only accept motivated students who have academic aspirations, i.e. those who wants to become researchers, teachers, or professors. We advise achieving personal and academic maturity before applying to graduate school. People with MS degree, work experience in research lab are preferred. Mature international students are welcomed.
