This award will be used to acquire materials for fabricating a laser fluorination system to prepare samples for oxygen isotope measurements. The laser fluorination system will allow small-scale isotopic variation studies, increase sample throughput, and allow isotope measurements on ?resistant? minerals. Isotopes will be used to understand the role of aqueous fluids in the genesis of magmas, hydrothermal systems, sedimentary basins, hydrothermal vent systems, shallow subduction zones, and in groundwater circulation. Water-rock interaction history will be applied to understand metamorphic rock exhumation. Laser fluorination would allow oxygen isotope measurements on individual minerals within rocks, allowing better constraints on geochronologic cooling. As part of the Geoscience Diversity Enhancement Program (GDEP), samples from the Catalina Schist will be analyzed by the new system to better understand petrologic and tectonic evolution. Oxygen isotope data from thermally-altered intrusions will be used to establish the degree of isotopic disequilibrium to estimate water-rock ratios and duration of hydrothermal activity in the Southern White Pine Range in Nevada. In addition, fluid inclusions will be analyzed using laser fluorination to reveal silica sources. Stable isotopes will be used to source historic gunflints and paleoindian quartzite tools. Biogenic silica and sediment organic matter will be analyzed and used as a proxies to estimate past oxygen and salinity concentrations. This fluorination system would allow CSULB to provide a system-wide facility for geology and archeology isotope and trace elements (GAITE) measurements. The instrument will be used for undergraduate and graduate-level student training. CSULB is a Hispanic Serving Institution and is highly ranked for conferring minorities with bachelors. The Institute for Integrative Research in Materials, Environments, and Society (IIRMES) was formally established in 2004 with a purpose to promote intellectual exchange and foster interdisciplinary collaborations among faculty and students with different educational and research backgrounds. The PI will be responsible for building the vacuum lines The instruments will be installed at the CSULB stable isotope laboratory in the IIRMES facility. The facility will operate as fee-based for outside samples.
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A laser fluorination system and vacuum line were constructed, tested, and implemented using $37,868 from an NSF Instrumentation and Facilities grant and $76,000 from CSULB internal infrastructure funds at the stable isotope laboratory houses in the Institute for Integrated Research in Environments, Materials, and Societies (IIRMES) at California State University, Long Beach. The laser system provides for the acquisition of precise and accurate oxygen isotope data from silicate and phosphate compounds from geologic, archaeologic, anc biologic materials. This new addition to the lab complement other inlet methods for gas source mass spectrometry that include a Costech elemental analyzer for the acquisition of carbon and nitrogen isotope data, a Thermo-Finnigan thermo-combustion elemental analyzer for the acquisition of oxygen and hydrogen isotope data from solids and liquids, and a ThermoFinnigan GasBench for the acquisition of carbon and oxygen isotope data from carbonates by acid dissolution and liquids by head-space equilibration. This new instrumentation is supporting the research of at least four faculty in the departments of geosciences and anthropology at three universities. Five graduate students are utilizing the laser system in the acquisition of stable isotope data for their thesis projects. Three undergraduate student research projects are also benefiting from this instrumentation. The laser fluorination system is the only facility of its kind availble for researchers in southern California, so its demands are expected to increase dramatically in the near future. Two projects have been completed since the installation and implementation of IIRMES laser fluorination system. Publication of results from these projects is expected and manuscripts are in preparation. The first project entitled "The Fluid Evolution of the Mount Mica Pegmatite: Evidence from Stable Isotopes" documents magmatic fluid history of a pegmatite system formed by anatexis as it cooled and crystallized under closed system conditions. The second project entitled "Stable Isotope Evidence for the Fluid Evolution of the Orocopia Schist, Southeastern California" documents the role of metamorphic and meteoric-hydrothermal fluids during the Paleocene metamorphism and Miocene exhumation of the Orocopia Schist at the Orocopia Mountains and Gavilan Hills localities.
