Sun. May 24, 2015 3:15 PM - 4:00 PM A04 (APA HOTEL&RESORT TOKYO BAY MAKUHARI)

Convener:*Hironobu Hyodo(Research Institute of Natural Sciences, Okayama University of Science), Hirochika Sumino(Geochemical Research Center, Graduate School of Science, University of Tokyo), Takahiro Tagami(Graduate School of Science, Kyoto University), Chair:Hirochika Sumino(Geochemical Research Center, Graduate School of Science, University of Tokyo), Hironobu Hyodo(Research Institute of Natural Sciences, Okayama University of Science)

Noble gas isotopes show unique chemical behavior by not forming compounds with other elements, and because of this they have been often used as important and distinctive geochemical and cosmochemical tracers. Since the first attempt on absolute dating was carried out using the U-He system, other dating methods involving noble gas isotopes, such as the K-Ar (Ar-Ar) system, have been developed and used as powerful tools in geochronology. Physical analysis of diffusion processes involving radiogenic noble gases in minerals has led to the concept of closure temperature, resulting in improved understanding of discordant ages between different isotope systems and their geologic interpretation. Recently developed `next generation' noble gas mass spectrometers enable isotope ratio determination at ultrahigh precision utilizing multi-collectors and high sensitivity ion source and detectors. These innovations facilitate high spatial resolution noble gas isotope measurements at the 10-microns scale in rocks and minerals. In this session, we welcome contributions from various cutting-edge analytical techniques and geoscience applications of noble gas isotopes including neutron conversion of other elements to noble gas isotopes and new insights from conventional methods.