Current Research Interests and Projects
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. The ion microprobe serves as an important complementary tool to study crystal domains although so far it has worse (±0.25‰), yet improving precision. Significant advances are being made, including the Cameca1280 lab in Wisconsin, as well as similar labs around the world (UCLA,Nancy, Stanford). While ion microprobes are rivaled by LA-MC-ICPMS methods, the precision and spatial resolution are still better when it comes to zircon U-Pb dating, trace element phenocryst profiling, and melt inclusion analysis, meaning that SIMS will quite possibly remain the best tool for stable isotope research for many years.
New generation of gas source mass spectrometers feature improved software and hardware, and multi-collector capabilities. It is possible to measure rare oxygen, rare CO2, and rare sulfur isotopes fairly easy. The new Finnigan MAT 253 large radius instrument has been installed and it has multi-collector capabilities for analyses of rare isotopes. It is now installed since August 2006. It is the “cornerpiece” instrument for the new stable isotope laboratory here at the University of Oregon. The mass spec has laser line,TC/EA system, GasBenchII, and a general purpose vacuum line with He flow capability and gas chromatographic column attached to it.
After leaving Caltech in December 04, (the room space in the 110C Cascade Hall was empty. Now the lab is full with equipment and is getting more and more items.We have working laser fluorination extraction line. The line has three pumps attached to it: a rotary vane, a diffusion, and a back ion pump; these pumps and Ni-gaskets VCR joints with Ni gaskets, all-metal electropolished tubing, high-flow diaphragm-valves, and small line size are getting tested for accuracy. The line permits 4 oxygen extractions per hour. A Newave 30W laser-motion system is used in our extraction and is the chief method used to react minerals in the sample chamber.
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.
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.
GasBenchII device, another continuous flow periferal device, is now used for precise 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. The GasBench can also be used for many other types of isotope analyses in different media and compounds. We analyze carbon and oxygen isotope composition of dissolved inorganic carbon in waters, which is relevant for Oregon lakes and rivers. GasBench permits analyses of waters for hydrogen and oxygen isotopes by equilibration with H2 and CO2 gases respectively, and analyses of atmospheric gases.
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
Topics of current Research:
Large volume silicic and basic volcanism in Kamchatka
Large basaltic fissure eruptions of Iceland
Explosive silicic volcanism of the Western US
Effects of large volcanic eruptions on climate: isotopic traces
Low temperature topics
Your Topic here…
To new graduate students: I suggest being knowledgble in geology, math, inorganic chemistry and have interest in lab and field work.
We only accept motivated students who have academic aspirations, i.e. those who wants to become researchers, teacher, or professors.
Given that it is hard to master such background during 4 year US college education, we advise achieving personal and academic maturity before applying to graduate school. People with MS degree, work experience in research lab with academic aspirations are clearly preferred. Mature international students are warmly welcomed.