A Teledyne Analyte G2 excimer laser ablation (LA) system was purchased for use with an existing high resolution inductively coupled plasma mass spectrometer (ICPMS) in the Geological Sciences department at California State University, Northridge (CSUN). This system was acquired in order to efficiently and precisely measure isotopic ratios in accessary minerals, with the goals of routinely collecting high-quality U-Pb geochronologic and trace geochemical data. Our laser ablation ICPMS facility is unique in the Los Angeles area and was acquired in large part to support the research activities of CSUN students, as well as students from other institutions in the Los Angeles basin, many of whom are from groups underrepresented in the Earth Sciences.

Intellectual Merit: The energy production, good beam focusing, and enhanced signal stability of the acquired laser ablation system has allowed the PIs to increase sample throughput, reduce spot size, and ablate for shorter durations. These capabilities have in turn allowed for better spatial resolution and development of grain mapping techniques, down-hole measurements, and targeted analysis of mineral growth domains. With the new laser system, the PIs have improved methods of U-Pb dating of zircon and titanite, and have developed new methods for trace element geochemical analysis of zircon, garnet, amphibole and pyroxene. These geochronologic and geochemical approaches are used broadly by the PIs and their students. The overall impact of this instrumentation is therefore similarly broad, as the laser ablation system has contributed to almost every collaborative project, student investigation, and research proposal developed by the PIs.

Broader Impacts: Since installing our new laser ablation system, it has been used to support the theses of 14 Masters students, and research experiences for over 20 undergraduate students at CSUN. The laser ablation ICPMS facility also benefitted an additional 13 BS and MS students over two years in a pilot PLASMA (Projects in Laser Ablation Spectrometry for Minority Achievement) Institute. Students were recruited who were working with advisors at their home institutions on projects for which detrital and / or igneous geochronologic data were needed. The PIs helped these students with sample preparation, data collection, and data interpretation, and provided group workshops on U-Pb geochronology, mass spectrometry, and data visualization. A PLASMA Institute is currently being implemented by PI Schwartz as part of a separate NSF award. In addition to research opportunities, the LA-ICPMS facility is also used for instructional purposes in upper division petrology and geochronology courses taught by the PIs.

The ability to routinely collect geochronologic and geochemical data with the LA-ICPMS has led to new collaborations between the PIs and researchers at universities and government agencies. These collaborations have broadened the scope of the research being carried out in the facility and have provided financial support for operations. Development of this laboratory has also been leveraged to obtain additional instrumentation through competitive awards at NSF and DOE, including a quadrupole mass spectrometer and a field emission scanning electron microscope. The laser ablation system has become a building block onto which a larger geoanalytical facility at CSUN is being constructed. Since acquiring the laser ablation system, the PIs have been awarded four additional research awards; all of which depend on datasets generated using the LA-ICPMS. Published geochronologic and geochemical datasets coming out of the laser ablation laboratory have been made available in public-access databases, thereby enhancing their impact. A total of 20 peer-reviewed papers, and over 30 conference abstracts, have been published by the PIs using data generated in with this laser ablation system. It is difficult to overstate the impact that this instrumentation has had on technique development, advancing research objectives, and supporting students at CSUN and elsewhere.

Last Modified: 03/17/2023
Modified by: Robinson Cecil