This Major Research Instrumentation (MRI) Program grant supports establishment of a noble gas thermochronometry laboratory (NGTL) at the Berkeley Geochronology Center. The NGTL would focus on (U-Th)/He and 4He/3He dating of accessory phases to establish their low temperature (< 200 degrees C) thermal histories. Equipment to be purchased includes a binocular microscope, components to a build gas extraction system including diode laser and ultrahigh vacuum laser extraction chamber, components to build an ultra high vacuum gas purification system and a quadrupole mass spectrometer. The laser heated gas extraction and purification system would be used to liberate He from samples which would subsequently be analyzed on the quadrupole mass spectrometer. Following gas analysis, recovered samples would be dissolved and solutions would be spiked for isotope dilution measurements of U and Th concentrations via ICP-MS analysis at available off campus facilities. NGTL capabilities for quantitative evaluation of the thermal histories of rocks below 200 degrees C will be used to establish timescales and rates of processes taking place in the uppermost few kilometers of terrestrial planets. A range of PI and collaborative research will be facilitated including: (i) quantifying the rates and timescales of exhumation, erosion and tectonism in mountainous landscapes and testing possible influences that climate variability has on relief, (ii) constraining the temperatures and timescales of near-surface planetary impacts and long-duration residence temperatures of the Martian meteorites while on Mars, (iii) quantifying the timescales and rates of chemical weathering at Earth's surface, (iv) constraining long-term residence timescales of samples near Earth's surface, and (v) studying noble gas diffusion kinetics in different materials to advance basic understanding of solid-state diffusion and potentially identify novel applications of the noble gases to the Earth and planetary science. Graduate and postdoctoral researchers will be trained in low-temperature thermochronometry research methods and the PI's plan targeted recruitments of women and minorities for graduate and postdoctoral fellowships.
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