Hugh P. Taylor, Jr.

GPS Home Page

Robert P. Sharp Professor of Geology

Division of Geological and Planetary Sciences
MC 100-23, Caltech
Pasadena, CA 91125

The Taylor Group | Current Stable Isotope Research | Research Facilities | Links
Chemical petrology of igneous and metamorphic rocks using the stable isotopes of Oxygen and Hydrogen
The Taylor Group
PhD Students

   » Elizabeth Holt (Geochemistry)
   » Edwin Schauble (Geology)


   » Mihai Ducea

Recent Graduates
(and Occasional Visitors)

   » Greg Holk
      (Queens University)
   » Diane Clemens-Knott
      (CalState Fullerton)

Current Stable Isotope Research Abstracts
Extremely short-lived fumarolic hydrothermal systems in the Bishop Tuff
Elizabeth Holt and Hugh P. Taylor, Jr.
Eclogitic residues from beneath the Sierra Nevada batholith, Similarities between granitoid extraction in Cordilleran and Archean settings
Mihai Ducea, Jason Saleeby, and Hugh P. Taylor, Jr.
Oxygen- and radiogenic-isotope relationships in Mesozoic and Cenozoic granitoids of the northeastern Great Basin, Nevada and Utah
Edwin Schauble, Hugh P. Taylor, Jr., and James E. Wright
Research Facilities

We maintain two types of systems for extracting oxygen from silicate minerals:

  • Conventional fluorination lines use electrically heated nickel vessels to promote the quantitative reaction of high-purity F2 gas with approximately 20 mg rock and mineral samples. A typical reaction:
    SiO2(quartz) + 2F2(g) => SiF4(g) + O2(g), at 500ºC
    This method is well suited to powdered rock samples and easily fluorinated minerals like quartz, feldspar, and micas. Two conventional fluorination lines are currently operational, in 307 N. Mudd and in the N. Mudd Penthouse.
  • Laser fluorination operates similarly, except that sample heating is accomplished with a focused 13W CO2 infrared laser. Much higher temperatures can be achieved with laser heating, so this method is ideal for hard-to-react minerals such as garnet, zircon, and olivine. Also, sample sizes are much smaller, about 2 mg, so that it is often possible to analyze single mineral grains. Very small blanks (< 0.1 mmol O2), and the ability to run extract up to 40 samples without venting the system mean that greater precision is often obtained with laser fluorination. The Caltech oxygen isotope laser fluorination system is located in 07 N. Mudd.
Additional facilities for the extraction of oxygen from carbonates, and hydrogen from a variety of sample types are also available.

After sample oxygen is extracted, purified, and converted to CO2, its 18O/16O ratio is measured with the Finnigan MAT 252 gas-source mass spectrometer in 07 N. Mudd.

LINKS Publications Bishop Tuff Xenoliths
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