Short communication: Inverse correlation between radiation damage and fission-track etching time on monazite

Toru Nakajima*, Shoma Fukuda, Shigeru Sueoka, Sota Niki, Tetsuo Kawakami, Tohru Danhara, Takahiro Tagami

*この論文の責任著者

研究成果: ジャーナルへの寄稿学術論文査読

1 被引用数 (Scopus)

抄録

In this study, we explored the impacts of radiation damage and chemical composition on the etching time of fission tracks in monazite. Despite the potential of monazite fission-track (MFT) dating as an ultralow-temperature thermochronology, the comprehensive effects of radiation damage and non-formula elements, especially on the etching rate of MFTs, remain unexplored, and established analytical procedures are lacking. We quantified the degree of radiation damage (1FHWM) in Cretaceous to Quaternary monazites distributed in the Japan arc through Raman spectroscopy and chemical composition analyses. Subsequently, MFT etching was performed to examine the correlation between these parameters and the etching time. Estimation of the degree of radiation damage showed an increase in radiation damage corresponding to the cooling age of each geological unit. For example, the Toya ignimbrite (ca. 0.1 Ma) and the Kurobegawa granodiorite (< 0.8 Ma), both of which are types of monazite from Quaternary geological units, have 1FHWM values of 0.27 and 0.55 cm−1, respectively. In contrast, the Muro ignimbrite (ca. 15 Ma) has a 1FHWM value of 4.01 cm−1, while the Kibe granite and the Sagawa granite, both of which are Cretaceous granitoids, yielded 7.35 and 6.31 cm−1, respectively. MFT etching of these samples according to the existing recipe (6 M HCl at 90 °C for 60–90 min) was completed at 1200, 860, 210, 120, and 90 min for the Toya ignimbrite, Kurobegawa granodiorite, Muro ignimbrite, Sagawa granite, and Kibe granite, respectively. These outcomes highlight an inverse relationship between MFT etching time and the degree of radiation damage in monazite, while the correlation between MFT etching time and chemical composition was unclear. The results affirm earlier considerations that the etching rate of MFTs is strongly influenced by radiation damage. Conversely, young samples with lower levels of radiation damage exhibit higher chemical resistance, suggesting that existing etching recipes may not adequately etch MFTs.

本文言語英語
ページ(範囲)313-323
ページ数11
ジャーナルGeochronology
6
3
DOI
出版ステータス出版済み - 2024/07/03

ASJC Scopus 主題領域

  • 地質学
  • 層序学
  • 古生物学

フィンガープリント

「Short communication: Inverse correlation between radiation damage and fission-track etching time on monazite」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル