To determine local deposit features in the vein-type gold–silver ore deposit of the historical Togi mine, Noto Peninsula, central Japan, we investigated the occurrence and chemical compositions of ore minerals, especially silver- and/or gold-bearing minerals, and wall-rock alteration in the Togo No. 3 tunnel, a major tunnel of the Urukami mining area of the Togi mine. In the tunnel, the stockwork veins which are generally 0.1–1.5 m wide runs in Neogene pyroxene andesite. In the ore-bearing quartz vein, in addition to the sulfides such as sphalerite, pyrite and chalcopyrite, the following Au and/or Ag ore minerals were identified: electrum with <49.3 mol% Ag, uytenbogaardtite, fischesserite, silver-rich minerals of the Ag₂S–Ag₂Se solid solution series, and Se-rich pearceite. Gangue minerals in the quartz veins are quartz and adularia. The wall rock is silicified, chloritized, and sericitized pyroxene andesite. Multiple generations of adularia grown on quartz suggest that adularia has grown by repeatedly passing the hydrothermal solution through the vein. Based on the characteristic occurrence of the Ag and/or silver-rich ore minerals such as electrum, fischesserite, and Se-rich pearceite and a gangue mineral, adularia, and on the wall-rock alteration characterized by chlorite, sericite, and calcite, the Togi deposit is classified as a Se-type and low-sulfidation epithermal gold vein deposit. The K-Ar ages of illite/smectite mixed-layer minerals from the altered outcrop and plagioclase from a fresh andesite sample are 17.68 ± 0.41 and 17.52 ± 0.43 Ma, respectively, in agreement with published data of the Besshodake andesite. These results indicate that the hydrothermal fluids generated by the Miocene andesitic magma activity infiltrated the fissures relating to the formation of the Togi-gawa Nangan Fault at the northern boundary of the Togi mining area, and Au and/or Ag-rich ore minerals were formed from the hydrothermal fluid with decreasing temperature at the shallow level.

中文翻译：

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日本能登半岛历史悠久的 Togi 矿浅成热液金银脉矿床的矿物学、年代学和形成过程

为了确定日本中部能登半岛历史悠久的 Togi 矿脉型金银矿床的局部矿床特征，我们调查了矿石矿物的产状和化学成分，特别是含银和/或含金矿物，以及Togi矿山Urukami矿区的主要隧道多哥3号隧道的围岩改变。隧道内，新近纪辉石安山岩中运行一般0.1～1.5 m宽的网纹脉。在含矿石英脉中，除闪锌矿、黄铁矿和黄铜矿等硫化物外，还鉴定出以下金和/或银矿石矿物：银<49.3 mol%的金银矿、uytenbogaardtite、fischesserite、富银矿物Ag ₂ S–Ag ₂硒固溶系列，富硒珠光体。石英脉中的脉石矿物为石英和金银花。围岩为硅化、绿泥石化和绢云母化辉石安山岩。多代生长在石英上的 adularia 表明，adularia 是通过反复使热液溶液通过静脉而生长的。基于金银矿、硅藻土、富硒珠光体等富银和/或银矿石矿物和脉石矿物adularia的特征产状，以及以绿泥石、绢云母和方解石为特征的围岩蚀变， Togi矿床为硒型低硫化浅成热液金脉矿床。来自新鲜安山岩样品的蚀变露头和斜长石的伊利石/蒙脱石混合层矿物的 K-Ar 年龄分别为 17.68 ± 0.41 和 17.52 ± 0.43 Ma，与 Besshodake 安山岩的公布数据一致。这些结果表明，中新世安山岩浆活动产生的热液渗入了与栃木矿区北部边界栃川南岸断层形成有关的裂缝中，形成了富金和/或银的矿石矿物。来自随着浅层温度降低的热液流体。