Study on formation mechanism of seafloor hydrothermal deposits based on Cu isotope measurement

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K03985
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 17030:Human geosciences-related
• Research Institution: University of Tsukuba
• Principal Investigator: IKEHATA KEI 筑波大学, 生命環境系, 准教授 (70622017)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 海底熱水鉱床 / 銅同位体

Outline of Final Research Achievements

Copper isotope compositions of copper-bearing minerals in seafloor hydrothermal deposits around Japan are within the range of those for reported main various copper-bearing minerals in modern seafloor hydrothermal deposits worldwide. Compared with ancient seafloor hydrothermal deposits which may have experienced more significant isotopic homogenization processes, initial (e.g., pre-metamorphic) copper isotopic characteristics of modern seafloor hydrothermal deposits are probably preserved. The spatial distribution of copper isotopic compositions in this study may reflect fluid pathways during hydrothermal activity.

Free Research Field

鉱床学・地球化学・火山学

Academic Significance and Societal Importance of the Research Achievements

本研究の結果から、海底熱水鉱床試料に含まれる様々な大きさの各種含銅鉱物の銅同位体組成は、鉱物組織（産状）と詳細に比較することで、銅の起源のみならず、これらの鉱物の晶出に関与した熱水の流路を評価・推定する指標になり得ると考えられる。これらの基礎的な情報は、ある海底熱水変質域中の鉱化流体の広がり（鉱量）や鉱床の品位の評価につながる可能性が高いことから、海底熱水鉱床の探査や開発に役に立つことが期待される。