Development of high-precision ultra-micro radiocarbon dating to accelerate high-resolution chronological studies

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K21894
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 17:Earth and planetary science and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Omori Takayuki 東京大学, 総合研究博物館, 特任研究員 (30748900)
• Project Period (FY): 2019-06-28 – 2024-03-31
• Keywords: 放射性炭素 / 加速器質量分析 / 微量分析

Outline of Final Research Achievements

This study aimed to establish an ultra-micro measurement method for radiocarbon dating that reduces the sample amount to one-thousandth of the conventional method. To achieve ultra-micro measurement, it was necessary to optimize chemical preparation and accelerator mass spectrometry(AMS), which is suitable for ultra-micro samples, and conduct technical evaluations while applying these methods to actual samples. In this study, I established a sample preparation system and AMS operation methods suitable for ultra-micro samples and conducted test measurements using AMS standard materials and the varved lacustrine sediments from Lake Suigetsu. This research demonstrated that with ultra-micro measurement, accurate dating can be performed for samples up to approximately 30Ka, and that an amount of at least 20 ug carbon is sufficient for practical use in dating to the last 20 Ka.

Free Research Field

年代学

Academic Significance and Societal Importance of the Research Achievements

本研究の達成により、今まで試料量の制限から年代をはかれなかった微量な有機物、例えば、土壌に含まれる花粉粒や微粒炭、生物組織を構成する特定の有機化合物など、実質的にみて年代測定できないものがないほど、AMSの応用範囲が拡大することになる。これにより、地球科学や考古学など、過去に目を向ける学術研究の時間的な解像度を飛躍的に向上させることが期待される。