Electron Microprobe Laboratory
Earth & Environmental Sciences
Rensselaer Polytechnic Institute
Jonsson Rowland Science Center BC09

Trace-Element Analysis & Thermometry

By combining counts from multiple spectrometers that use "oversized" PET and LIF crystals (providing high x-ray count rates), we can achieve detection limits in the 20-40 ppm range, suitable for application of the Zr-in-rutile, Zr-in-sphene and Ti-in-Quartz (TitaniQ) thermometers in a range of rock types.

Wark D. A. and Watson E. B. (2006) TitaniQ: A titanium-in-quartz geothermometer. Contributions to Mineralogy and Petrology 152(6), 743-754.

Watson E. B., Wark D. A., and Thomas J. B. (2006) Crystallization thermometers for zircon and rutile. Contributions to Mineralogy and Petrology 151(4), 413-433.

EMP Analysis & Imaging

Our Cameca SX-100 electron microprobe is used for chemical analysis and for electron- or CL imaging of geological, metallurgical, ceramic, glass, and other materials.

Equipment purchase funded in part by the National Science Foundation

Our instrument is configured for simultaneous analysis of all rare earth elements plus U, Th, and Pb. This allows precise determination of chemical ages from monazite, and of temperatures of equilibration for monazite-xenotime assemblages.

Pyle J. M., Spear F. S., Rudnick R. L., and McDonough W. F. (2001) Monazite-xenotime-garnet equilibrium in metapelites and a new monazite-garnet thermometer. Journal of Petrology 42(11), 2083-2107.

Pyle J. M., Storm L. C., Spear F. S., Wark D. A., and Daniel C. G. (2005) Contributions to precision and accuracy of monazite microprobe ages. American Mineralogist 90(4), 547-577.

The electron microprobe uses a focused electron beam to generate characteristic x-rays from a flat, polished, solid material.

Click here for a very general introduction to this technique.

With Gatan's monoCL3 imaging and spectroscopy system, we can collect high-resolution, cathodoluminescence images and spectra - even from crystals with weak CL emissions, such as quartz.

Wark D. A., Watson E. B., Hildreth W., Spear F. S., and Cherniak D. J. (2007) Pre-eruption recharge of the Bishop magma system. Geology 35(3), 235-238.