Updated on 2025/04/30

写真a

 
GONOI, Yuji
 
Affiliation
Faculty of Science and Engineering, School of Creative Science and Engineering
Job title
Assistant Professor(non-tenure-track)

Research Experience

  • 2025.04
    -
    Now

    Waseda University   School of Creative Science and Engineering   Assistant professor

  • 2024.04
    -
    2025.03

    Waseda University   School of Creative Science and Engineering   Assistant professor

Education Background

  • 2018.04
    -
    2022.03

    Kyushu University   Faculty of Engineering   Department of Earth Resources Engineering  

  • 2014.04
    -
    2016.03

    Nagoya University   Graduate School of Environmental Studies   Department of Earth and Environmental Sciences  

  • 2010.04
    -
    2014.03

    University of Toyama   Faculty of Science   Department of Earth Science  

Professional Memberships

  • 　
    　
    　

    Society of Economic Geologists

  • 　
    　
    　

    資源地質学会

Research Areas

  • Earth resource engineering, Energy sciences / Human geosciences

Research Interests

  • 金鉱床

  • 粘土鉱物

  • 資源探査

  • 熱水変質

  • 資源地質学

  • 浅熱水系

▼display all

Awards

  • 優秀ポスター賞

    2015.09   日本地質学会   愛知県の中央構造線沿いに産する食い違い礫の自己修復作用とその応用

    Winner： 五ノ井祐二, 吉田英一

 

Papers

  • High temperature wall-rock alteration zoning in the Sanjin deposit, Hishikari gold mine, Japan: Implication for exploration of mature mining districts

    Yuji Gonoi, Akira Imai, Kotaro Yonezu, Thomas Tindell, Adrian J. Boyce, Jun ichiro Ishibashi

    Journal of Geochemical Exploration   240  2022.09  [Refereed]

    Authorship：Lead author, Corresponding author

    　View Summary

    The Sanjin deposit is one of three major ore zones hosted by Pleistocene quartz-adularia veins being mined at the Hishikari low-sulfidation epithermal gold mine, which has produced more than 242 t of gold at an extraordinary average grade since 1985. Hydrothermal alteration zoning of the Sanjin deposit was examined with respect to mineralogy, geochemistry, fluid inclusion microthermometry, and oxygen and hydrogen isotopes. Clay minerals are dominated by interstratified chlorite-smectite (C/S) and interstratified illite-smectite (I/S) with <20% smectite. Epidote and prehnite are recorded for the first time at Hishikari in the southeastern part of the Sanjin deposit, typically coexisting with chlorite. Trapping temperatures of fluid inclusions from associated ore zone quartz veins typically range from 195 to 230 °C, with higher temperatures prevalent in the southeastern part of the Sanjin deposit. The calculated fluid δ18O and δ2H values from clay minerals and quartz cannot be explained by a simple water-rock interaction or a simple fluid mixing model, since variable isotopic exchange temperature and endmembers have to be considered. This suggests that both water-rock interaction and mixing of fluids occurred between dynamically variable end members during mineralization. The average estimated formation temperature of chlorites in the Sanjin deposit using chlorite geothermometry is 233 ± 19 °C, in agreement with the highest temperature zone in Hishikari, estimated by homogenization temperature of fluid inclusions of ore veins. In addition, the estimated formation temperatures of chlorite in epidote- and/or prehnite-rich altered rocks are higher (avg. 240 ± 17 °C) than those in epidote- and/or prehnite-poor altered rocks (avg. 216 ± 9 °C). Thus, the chlorite-epidote/prehnite assemblage can be an index of a high temperature alteration zone in the Sanjin deposit. Considering the position of the paleo-water table of the three ore zones, these factors are consistent with the formation of the Sanjin deposit proximal to the upflow zone responsible for gold mineralization at Hishikari. We suggest that our approach could be utilized to understand the thermal structure of epithermal gold system, which may be important to explore for blind veins at mature mining districts.

    DOI

    Scopus

    2
    Citation
    (Scopus)

Presentations

  • Reexamination of hydrothermal alteration and mineralization in the Iriki district, northern Kagoshima, Japan

    Jun Ito, Yuji Gonoi, Kotaro Yonezu, Akira Imai, Junya Oshika

    International Symposium on Earth Science and Technology 

    Presentation date： 2024.11

    Event date：
    2024.11
    　
    　

  • Chemical properties of epidote and prehnite in the Sanjin deposit, Hishikari mine, Japan

    Gonoi, Y, Imai, A, Yonezu, K, Tindell, T, Ishibashi, J, Watanabe, K

    International Symposium on Earth Science and Technology 

    Presentation date： 2020.11

    Event date：
    2020.11
    -
    　

  • Variations in mineral assemblages and oxygen and hydrogen isotopes of wall rock alteration in the Hishikari epithermal gold deposit, Japan

    Gonoi Y, Imai A, Yonezu K, Tindell T, Boyce A.J, Watanabe K

    JpGU - AGU Joint Meeting 2020 

    Presentation date： 2020.07

  • New implication of wall rock alteration mineralogy in the Hishikari epithermal gold deposit, Japan

    Gonoi, Y, Imai, A, Yonezu, K, Tindell, T, Watanabe, K

    New Zealand Geothermal Workshop 

    Presentation date： 2019.11

  • Subdivision of wall rock alteration zoning in the Hishikari epithermal gold deposit, southern Kyushu, Japan

    Gonoi, Y, Imai, A, Yonezu, K, Tindell, T

    15th Biennial SGA Meeting, 

    Presentation date： 2019.08

  • 菱刈鉱床母岩の熱水変質分帯の再検討

    五ノ井祐二, 今井亮, 米津幸太郎, Tindell Thomas, 渡邊公一郎

    資源地質学会第 69 回年会学術講演会 

    Presentation date： 2019.06

  • 愛知県の中央構造線沿いに産する食い違い礫の自己修復作用とその応用

    五ノ井祐二, 吉田英一

    日本地質学会第122年学術大会（長野大会） 

    Presentation date： 2015.09

▼display all

Research Projects

  • 浅熱水性鉱床と深部変質化学ゾーニングー本邦における新規金探鉱に向けてー

    日本学術振興会  科学研究費助成事業

    Project Year :

    2024.07
    -
    2026.03
     

    五ノ井 祐二

 

Syllabus

 

Internal Special Research Projects

  • 福岡県星野地区における浅熱水金銀鉱床の成因的研究

    2024   今井　亮, 米津　幸太郎, 野崎　達生, 鳥本　淳司

    　View Summary

    　福岡県八女市の星野地区，特に西部の大規模鉱脈において地表踏査，岩石試料採取を行い，早稲田大学創造理工学部環境資源工学科の実験室において，鉱脈および母岩試料の偏光顕微鏡観察，X線回折 (XRD)，蛍光X線のマッピング分析 (Mapping-ED-XRF)を行った．その結果，鉱脈は石英脈および熱水角礫岩 (母岩片，石英脈片を含む) からなり，熱水角礫岩が大部分を占めることが明らかになった．石英脈は大部分が細粒～極細粒の石英からなり，塊状 (massive) 組織，葉片状 (bladed) 組織，櫛歯状 (comb) 組織を示し，熱水角礫岩は黒色～灰色のごく細粒シリカの基質からなる．また，母岩は脈際では珪化，緑泥石・イライト化，粘土化がみられることが明らかとなった．産業技術総合研究所 地圏資源環境研究部門において，石英脈の流体包有物の測定を行い，均質化温度，氷融解温度から推定される鉱化流体の捕獲温度，塩濃度はそれぞれ平均約180℃，約1％であることが明らかになった．以上のような脈石および母岩鉱物の特徴は，地下深く循環した中性熱水によって形成されたと考えられる．一方，地域北側において，白色および玉髄質の基質からなる熱水角礫岩の産出が確認され，顕微鏡観察およびXRDの結果，粒径300 µm程度の結晶質の明礬石の存在が確認された．一般的に結晶質の明礬石は，深成 (地下水面下最大2 km) のマグマ性揮発性物質を含む酸性熱水によって形成されたと考えられる．来年度は，これらの性質の異なる熱水活動の時間および空間的関係について，また，地区東側の熱水系についてもさらに研究を進めていく予定である．