Acquisition of a Noble Gas Mass Spectrometer for the Oregon State University 40Ar/39Ar Geochronology Laboratory

Oregon State University, Corvallis OR

Investigators

Abstract

Earth system scientists increasingly explore research frontiers that require precise timing of physical, chemical and biological processes. With the precise and accurate measurement of geological ages they are able to correlate and link past events in the Earth's geological record and determine durations and rates at which processes act. The application of 40Ar/39Ar age dating techniques is especially critical to addressing many of the grand scientific challenges in hotspot geodynamics, large-scale cataclysmic volcanism, paleo-environmental impacts, lunar crust formation and geological time scale calibrations. The acquisition of a state-of-the-art ARGUS VI multi-collector noble gas mass spectrometer to the 40Ar/39Ar Geochronology Laboratory at the College of Oceanic & Atmospheric Sciences at Oregon State University is significantly improving the capability to conduct 40Ar/39Ar experiments on very small samples from dredged submarine basalts and deep sea drill cores, fine-grained terrigenous sediment fractions to use as paleoproxies to study sediment transport and climate change, extremely small fragments of lunar impact melts and breccias, and low-potassium lavas from large oceanic igneous provinces in order to unravel their temporal evolution and their world-wide environmental impacts. The Oregon State University 40Ar/39Ar Geochronology Laboratory has been in operation since 1977 and functions as a multi-user facility for both scientists and students, within and outside the United States. With more than 75 visitors and students over the last 17 years, 70 collaborators over the last 3 years, and more than 175 publications, this NSF-sponsored laboratory has established itself as a widely-used facility, specifically focused on the geochronology of ocean crust, seamounts, marine sediments and large igneous provinces. The new ARGUS VI mass spectrometer will operate in tandem with the current MAP 215-50 mass spectrometer and will allow for a continued active participation of undergraduate and graduate students and post-doctoral fellows in this laboratory, training them in noble gas analytical techniques and the use of the NSF-sponsored ArArCALC software.