[M-TT48] 地球化学の最前線

[MTT48-P04] 地球表層物質の宇宙線生成核種(10Be, 26Al)の分析方法の改良と地球科学研究

*横山 祐典^1,2,3、山根 雅子⁷、中村 淳路⁴、宮入 陽介¹、堀内 一穂⁵、阿瀬 貴博¹、松崎 浩之⁶、白濱 吉起⁴、安藤 有加¹ (1.東京大学　大気海洋研究所 高解像度環境解析研究センター、2.東京大学　大学院理学系研究科　地球惑星科学専攻、3.海洋研究開発機構　生物地球化学研究分野、4.産業技術総合研究所　地質調査総合センター、5.弘前大学　理工学部、6.東京大学　総合研究博物館、7.名古屋大学　宇宙地球環境研究所 年代測定研究部)

キーワード：宇宙線生成核種、加速器質量分析

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.