Research on provenance study using quartz grain surface microtextures

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K16351
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Geography
• Research Institution: National Research Institute of Police Science
• Principal Investigator: Itamiya Hiromi 科学警察研究所, 法科学第三部, 研究員 (40645488)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 石英粒子 / 表面形態 / 円磨度 / フラクタル次元 / 主成分分析 / 共焦点レーザー顕微鏡 / 表面粗さ

Outline of Final Research Achievements

The microtexture of a quartz surface reflects the sedimentary history of the grain, including its parent rock, transportation process, and depositional environment. In this study, we examined the relationship between quartz morphological features and sedimentary history to apply surface textural analysis to provenance study in Japan.
Fluvial sediments and coastal sands were collected in Japan, and quartz grains after chemical treatment were observed by scanning electron microscope. It is revealed that quartz surface analysis has the potential to show the morphological variation and provide useful information on the provenance study. Furthermore, 3D measurement of v-shaped percussion cracks, one of the surface microtextures, was developed. This analysis can contribute to reveal the subaqueous environment of fluvial and marine sediments.

Free Research Field

法科学

Academic Significance and Societal Importance of the Research Achievements

日本の土における石英粒子の形態的特徴の多様性を確認し、後背地の推定に有用であることを示した。一方、先行する欧米諸国の研究とは必ずしも同様の傾向を示さないことも明らかとなり、日本の地質や地形的特徴を踏まえた考察を行う必要があると示唆された。土砂の後背地を推定し、「いつ、どこで、どのような地形変化が起こったのか」を明らかにする研究は、自然地理学における地域的多様性や地形変遷の解明、防災学における将来の自然災害の予測や土地の危険度の評価などに貢献できると考えられる。