[M-TT48] Frontiers in Geochemistry

[MTT48-P04] In-situ and meteoric 10Be and 26Al measurements: Improved preparation and application at the University of Tokyo

*Yusuke Yokoyama^1,2,3, Masako Yamane⁷, Atsunori Nakamura⁴, Yosuke Miyairi¹, Kazuho Horiuchi⁵, Takahiro AZE¹, Hiroyuki Matsuzaki⁶, Yoshiki Shirahama⁴, Yuka Ando¹ (1.Atmosphere and Ocean Research Institute, University of Tokyo, 2.Department of Earth and Planetary Science, University of Tokyo, 3.Department of Biogeochemistry, Japan Agency for Marine-Earth Science and Technology, 4.Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, 5.Graduate School of Science and Technology, Hirosaki University, 6.Micro Analysis Laboratory, Tandem Accelerator, University of Tokyo, 7.Division for Chronological Research, Institute for Space–Earth, Environmental Research, Nagoya University)

Keywords:Cosmogenic nuclides, Accelerator Mass Spectrometry

Cosmogenic radionuclides have been widely used to decipher Earth surface processes. At the University of Tokyo Accelerator Mass Spectrometry facility (5 MV Tandem accelerator), we have been measuring both in-situ and meteoric cosmogenic 10Be and 26Al. In this presentation, we report some development of methodology, including how to prepare target samples chemically to reduce their background. We then introduce some examples using the method to provide further insights into earth surface processes. These studies include: i) exposure to reveal the history of the growths and decays of the Antarctic ice sheet, ii) studying ice shelf collapse history, iii) palaeomagnetic excursion reconstructions using ice cores, iv) understanding the erosion rates using depth profiles of mid latitude outcrops, v) providing the timing of impact crater formation.

Reference: Yokoyama et al (2019) Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atom. https://doi.org/10.1016/j.nimb.2019.01.026.