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Characteristics and Mineralization Age of the Fukusen No. 1 Vein,Hishikari Epithermal Gold Deposits,Southern Kyushu,Japan |
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| Authors: | Yuki Tohma Akira Imai Kenzo Sanematsu Kotaro Yonezu Ryohei Takahashi Masaaki Koyama Ryota Sekine Robert Duncan Koichiro Watanabe |
| Institution: | 1. Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
Present addresses: Nippon Mining Exploration and Development, Tokyo, Japan;2. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan;3. Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan;4. Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan Research Institute of Engineering for Sustainability, Faculty of Engineering, Kyushu University, Fukuoka, Japan;5. Hishikari Mine, Sumitomo Metal Mining Co. Ltd., Hishikari, Kagoshima, Japan;6. College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, USA |
| Abstract: | The Fukusen No. 1 vein is located in the southeastern part of the Yamada deposit, Hishikari epithermal gold deposits, southern Kyushu, Japan. 40Ar/39Ar plateau ages of adularia from the margin and the center of the Fukusen vein are determined to be 0.617 ± 0.024 Ma and 0.606 ± 0.009 Ma, respectively. The Fukusen No. 1 vein shows banding structure composed mainly of quartz, adularia and clay minerals. Colloform texture is displayed by cryptocrystalline to amorphous silica material that is associated with fine-grained electrum and sulfides near the center of the vein. Pyrite in the Fukusen No. 1 vein often shows acicular shape resulting from inversion from marcasite. Near the center of the vein, primary marcasite occurs associated with colloform texture of silica. The Fukusen No.1 vein preserves primary texture and materials which were deposited from the ore-forming hydrothermal solution. The Fukusen No. 1 vein was formed in a short period and is one of the youngest veins in the Hishikari deposits. |
| Keywords: | 40Ar/39Ar dating adularia colloform texture electrum epithermal gold deposit Hishikari |