Achievement of accurate C-14 dating for charcoal based on a chemical index

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H02947
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Cultural assets study and museology
• Research Institution: Nagoya University
• Principal Investigator: MINAMI MASAYO 名古屋大学, 宇宙地球環境研究所, 准教授 (90324392)
• Co-Investigator(Kenkyū-buntansha): 鍵 裕之 東京大学, 大学院理学系研究科(理学部), 教授 (70233666) ; 三村 耕一 名古屋大学, 環境学研究科, 准教授 (80262848)
• Research Collaborator: TOMIYAMA SHINJI 名古屋大学, 大学院環境学研究科 ; NAKAMURA TOSHIO 名古屋大学, 名誉教授 (10135387)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 炭素14年代 / 炭化物 / 化学処理 / 元素分析 / 赤外吸収スペクトル / 蛍光X線回折パターン

Outline of Final Research Achievements

This study assesses two pre-treatments of charcoal samples: acid-base-acid (ABA) treatment and acid-base-oxidation with stepped combustion (ABOx-SC) treatment. In addition to C14, the effects of the treatments on the chemical structure and composition of charcoal were studied.
The ABOx-treated charcoal yielded older C14 dates than the ABA-treated samples, probably owing to the effects of removing organic contaminants bound to the edges of the aromatic molecular structures produced by the original pyrolysis. This investigation of the structural and compositional changes of charcoal during its pre-treatment demonstrates that oxidation treatment and stepped combustion can remove contaminants preferentially from the ABA-treated charcoal and ABOx-treated charcoal, respectively. Especially, the stepped combustion, not the chemical oxidation, is a key to reduce contaminant residue left after ABA and ABOx treatments.

Free Research Field

同位体地球化学、文化財科学