Acquisition of a multi-collector mass spectrometer for the University of Wisconsin Rare Gas Gechronology Laboratory

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

0741794 Singer This award will fund a rare gas multi-collector mass spectrometer at the University of Wisconsin dedicated to improving the precision, accuracy, and capacity of 40Ar/39Ar dating applied to Quaternary problems. Development of a highly-calibrated 40Ar/39Ar-based geomagnetic instability timescale (GITS) that can be correlated within marine and continental sediments via magnetostratigraphy is among the primary objectives of the primary investigators (PI's) during the next decade. Precise 40Ar/39Ar dating of these materials demands ever increasing numbers of isotopic measurements, often on K-poor lavas, thereby challenging the best technology in most laboratories. One way to confront this issue involves using a new generation multi-collector mass spectrometer with ion counting electron multipliers. The potential impact on geochronology, particularly at the younger end of geologic time, is great. Not only are measurements using multi-collection more precise than is possible on a single collector instrument, but they can be done more than twice as rapidly on samples of less than half the size. The Rare Gas Geochronology Laboratory has established a tradition of making its technology available to the wider Earth Science community. This includes multidisciplinary research supported by a diverse group of NSF Divisions, including Earth Sciences (EAR), Ocean Sciences (OCE), Antarctic (ANT), and Environmental Biology (DEB). Thus far, twenty-two students at the undergraduate, graduate and post-doctoral levels from UW-Madison and ten other institutions have trained with the PI's. The PI's plan to continue this educational commitment by participating in the EARTHTIME network as a national "geochronology node" where paleontologists, stratigraphers, and students from diverse backgrounds will be welcome to work in the laboratory and gain a first-hand appreciation of the methods and technology employed to determine precise ages. EARTHTIME also involves an aggressive campaign to increase the general public's awareness of the importance of geochronology.