Genesis of gold and platinum group element precipitation - new developments in elucidation of nano-level morphology

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K03758
• 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: Shizuoka University
• Principal Investigator: MORISHITA Yuichi 静岡大学, 防災総合センター, 客員教授 (90358185)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 金 / 白金 / SIMS / IRMS / 微小領域分析 / 深さ方向分析 / 鉱床成因

Outline of Final Research Achievements

Gold and platinum group elements are unevenly distributed on a microscopic scale in nature, and are often invisible even with a microscope due to their microscopic size. The relationship between gold and arsenic concentrations was investigated using secondary ion mass spectrometry (SIMS) in small regions less than 10 micrometers in pyrite from various gold deposits, and the existence form of gold and the properties of hydrothermal fluids were inferred.
On the other hand, SIMS was used to analyze the platinum concentration in ferromanganese crusts collected from seamounts, and the existence form of platinum was clarified. In addition, the properties of the hydrothermal fluid that produced several metal deposits were investigated by stable isotope measurements of minerals.

Free Research Field

鉱床学

Academic Significance and Societal Importance of the Research Achievements

金と白金族元素は、産業において様々な重要な役割を担っている。これら希少な元素は自然界においてミクロなスケールで偏在している事が多いために、未解明な課題も多い。陸上の様々なタイプの金鉱床と、将来の資源として注目される海底の鉄マンガンクラストを対象として、二次イオン質量分析法(SIMS)で金と白金を微小領域分析し、それらの存在形態を明らかにした。
安定同位体比分析による鉱床鉱物の研究と合わせ、これらの研究から学術的には鉱床の成因解明、社会的には資源を得るための知見が得られる。