The controls on precious metals content of massive sulfide deposits

2023 Fiscal Year Research-status Report

• Project/Area Number: 20K05395
• Research Institution: Akita University
• Principal Investigator: AGANGI ANDREA 秋田大学, 国際資源学研究科, 教授 (20840812)
• Co-Investigator(Kenkyū-buntansha): 高橋 亮平 秋田大学, 国際資源学研究科, 准教授 (10396286)
• Project Period (FY): 2020-04-01 – 2025-03-31
• Keywords: Kuroko / Massive sulfide deposit / Metals / Hydrothermal process

Outline of Annual Research Achievements

During fiscal year 2023, new analyses were performed, including Pb isotope analyses at the University of Johannesburg, South Africa and element mineral analyses at Akita. The Pb isotope analyses will be combined with previous trace element analyses (including Au and Ag) in order to infer the source of precious metals in the Kuroko. This is a central part of the planned work submitted in the original plan.
Analyses of sulfides will help constrain the contents of Au and Ag of the individual mineral phases. In addition, analyses of volcanic host-rocks, including whole-rock and mineral analyses, will be used to constrain the volcanic processes that produced hydrothermal circulation and ore deposition.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

The results of this research are overall satisfactory so far. A good proportion of the analyses have been completed, although data gathering will continue through fiscal year 2024. Some delay was introduced due to the difficulty to book the laboratory at University of Johannesburg. However, this was solved within 2023, and the data were collected in September 2023. Further delay was introduced by the necessity to process large a number of samples in order to find the appropriate sample material for analysis. Because of this sample processing will continue in the next months. Data elaboration and manuscript writing for publication is currently underway.

Strategy for Future Research Activity

Data gathering will continue through fiscal year 2024, along with data interpretation and write-up for conference presentations and manuscript submission. Part of these results will be presented in two conference presentations scheduled in Tokyo in 2024 (May 20240 and Busan, Korea (Aug 2024). A manuscript is currently in preparation for submission to an international journal, and is expected to be submitted for publication later this year.

Causes of Carryover

Some delay was encountered during 2023, which postponed some expenses. The carried-forward amount will be used for sample analysis over the next few months.

Research Products

• [Journal Article] Association and textural-compositional evolution of pyrite-organic matter in coals of the Tarakan, Barito, and Pasir Basins, Kalimantan, Indonesia (2024)
  • Author(s): Patria, A A., Suhendra, R, Anggara, F, Agangi, A, Obrochta, S P., Setiawan, I
  • Journal Title: International Journal of Coal Geology Volume: 282 Pages: 104442
  • DOI: 10.1016/j.coal.2023.104442
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The Age and Origin of the Ruwai Polymetallic Skarn Deposit, Indonesia: Evidence of Cretaceous Mineralization in the Central Borneo Metallogenic Belt (2023)
  • Author(s): Dana, C D.P., Agangi, A , Idrus, A et al.
  • Journal Title: Economic Geology Volume: 118 Pages: 1341
  • DOI: 10.5382/econgeo.5009
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Geology and geochemistry of gold mineralization at the Namicupo prospect, Mozambique Belt, northeastern Mozambique (2023)
  • Author(s): Nopeia M., Imai A., Takahashi R., Yonezu K., Manalo P.C., Tindell T., Sato H., Jamal D, Agangi A.
  • Journal Title: Journal of Geochemical Exploration Volume: 249 Pages: 107220
  • DOI: 10.1016/j.gexplo.2023.107220
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Zinc enrichment and isotopic fractionation in a marine habitat of the c. 2.1 Ga Francevillian Group: A signature of zinc utilization by eukaryotes? (2023)
  • Author(s): Ossa Ossa F., Pons M.-L., Bekker A., Hofmann A., Poulton S.W., Andersen M.B., Agangi A., Gregory D., Reinke C., Steinhilber B., Marin-Carbonne J., Schoenberg R.
  • Journal Title: Earth and Planetary Science Letters Volume: 611 Pages: 118147
  • DOI: 10.1016/j.epsl.2023.118147
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Proximal to distal geochemical variations of the Ruwai polymetallic skarn deposit, Central Borneo, Indonesia: Insights from sulfides chemistry and implications to exploration (2023)
  • Author(s): Idrus, A., Dana, C.D.P., Lai, C.-K., Lai, Agangi, A., Takahashi, R., Rajagukguk, E.H.
  • Journal Title: Journal of Geochemical Exploration Volume: 246 Pages: 107161
  • DOI: 10.1016/j.gexplo.2023.107161
  • Peer Reviewed / Int'l Joint Research
• [Presentation] A trace element and C-O isotope study of Sb-Au vein-hosting carbonate-talc schists of the Murchison Greenstone Belt, South Africa (2023)
  • Author(s): Agangi, A., Hofmann, A., Bolhar, R.
  • Organizer: Society of Economic Geology conference, London Aug 2023
  • Int'l Joint Research
• [Presentation] Geological and geochemical characterization of the Mugomo gold prospect, Tete province, northern Mozambique (2023)
  • Author(s): Cossa, E.P.F., Agangi, A., Takahashi R., Manalo P.C, Imai, A., Manjate, V.
  • Organizer: Society of Economic Geology conference, London Aug 2023
  • Int'l Joint Research
• [Presentation] Evolution of ore fluids for gold mineralization in the Neoproterozoic Xixano Complex, Mozambique Belt, Mozambique. (2023)
  • Author(s): M. Nopeia, A. Imai, R. Takahashi, A. Agangi, K. Yonezu, D. Jamal
  • Organizer: The 72nd Annual Meeting of the Society of Resource Geology of Japan
• [Presentation] Petrography and Mineralogical Characteristics of the White Pidgeon and Somerset Gold Deposits in the Vumba Greenstone Belt of Northeastern Botswana (2023)
  • Author(s): L. Mokane, A. Agangi, R. Takahashi, K. Phili
  • Organizer: JpGU 21-26 May 2023