Gold Japanese

Figure 1.6. Di.stribution and temporal and spatial relationship of late Cenozoic gold deposits in the Japanese Islands. 1 Quartz vein-type gold deposits with little to no base metals. 2 Gold-silver deposits with abundant base metals. 3 Distribution boundary of gold deposits formed during the Miocene. 4 Location of Plio-Pleistocene gold deposits at the actual island arc junctions. 5 Location of Plio-Pleistocene gold deposits in front of the actual island arc junctions. Numbers in the figure are K-Ar ages of epithermal Au-Ag veins (Kubota, 1994).

Figure 1,188. Typical sulfur activity and temperature ranges for Japanese auriferous vein (dotted) and gold-silver vein (hatched) deposits. I.so-FeS content curves for sphalerite were drawn based on the equation of Barton and Skinner (1979). py pyrite, po pyrrhotite (Shikazono and Shimizu, 1987).

Aq- (Fig. 1.189), while an increase in pH causes a decrease in wrAucr/ Au(Hsr It is apparent in Fig. 1.190 that Au bisulfide species are more abundant than Au cliloride species under the conditions common for ore fluids responsible for Japanese Au-Ag veins. However, Au chloride species may dominate Au bisulfide species in ore fluids responsible for the gold-quartz (auriferous) vein deposits, as shown in Fig. 1.189. 

Figure 1.189. The relationship between tAuCl / Au(HS)" temperature. Hatched and dotted areas represent the probable geochemical environment for typical Japanese gold-silver vein and auriferous vein deposits, respectively. A, mci- = 10, mK+ =2, qh2S = 10, K-feldspar/K-mica/quartz equilibrium B, mQ- = 1. niK+ =0.2, H2S = 10 - , K-feldspar/K-mica/quartz equilibrium C, mci- — 1, Wk+ =0.2, qh2S = 10, K-feldspar/K-mica/quartz equilibrium D, mci- =0.2, mK+ =0.04, oh2S = 10 , K-feldspar/K-mica/quartz equilibrium E, mci- =0.2, m <+ =0.04, uh s = 10 K-feldspar/K-mica/quartz equilibrium F, mci- =0.2, = 0.04, UHiS = 10 , K-feldspar/K-mica/quartz equilibrium. Thermochemical data for the calculations were taken from Helgeson (1969), Seward (1973), Drummond (1981), and Henley et al. (1984). (Shikazono and Shimizu, 1987).

Abe, H. (1981) Chemical compositions of gold ores and Ag/Au values of electrums from the Oya mine. Mining Geology Special Issue, 10, 119-125 (in Japanese with English abst.). 

Aoki, M. (1988) Gold mineralization in the Osorezan hydrothermal system — Rock alteration and hot spring precipitates. Mining Geology, 38, 64 (in Japanese). 

Ibaraki, K. and Suzuki, R, (1990) Wall rock alteration in the Hishikari gold mine, Kagoshima Prefecture, Japan. Mining Geology, 40, 97-106 (in Japanese with English abst.). 

Imai, H. (1986) Formation of potash feldspar in the propylites in the epithermal gold-silver mining areas (Preliminary report). Mining Geology, 36, 231-238 (in Japanese). 

Izawa, E. (1988) Science of exploration for gold. Kagaku (Science), 58, 15-23 (in Japanese). 

Kitami, M. (1973) Recent exploration and development of the Takatama gold and silver mine, Fukushima Prefecture. Mining Geology, 23, 191-197 (in Japanese). 

Koga, A. (1961) Gold in Beppu thermal spings. J. Chem. Soc. Japan, 82, 1476-1478 (in Japanese with Enghsh abst.). 

Kubota, Y. (1991) Significance of cauldrons as potential sites of gold deposits. Mining Geology, 41, 379-386 (in Japanese). 

Kubota, Y. (1994) Temporal and spatial relationship and significance of island arc junction on the late Cenozoic gold deposits in the Japanese Islands. Resource Geology, 44, 17-24 (in Japanese). 

Matsukuma, T. (1985) Gold and silver in the Kuroko deposits. In Mining and Metallurgical Institute of Japan (ed.). Gold and Silver Ore in Japan, 155-193 (in Japanese). 

Miyashita, A. (1995) Were the epithermal gold-silver deposits in the Hokusatsu region formed in association with cauldrons Resource Geology, 45, 313-321 (in Japanese). 

Takahashi, M. Ishiyama, T. and Mizuta, T. (1998) Structure and environment of formation of the Hosen No. 5 and Ryosen No. 5 gold-quartz veins, Hishikari mine. Japan. Rep. Inst. Appl. Earth Sci. Dep. Geosci. Akita U., 63, 55-72 (in Japanese with English abst.). 

Takenouchi, S. (1981) Fluid inclusion studies from Nansatsu-type gold deposits. Abstr., Annual Joint Meet., Soc. Min. Geol Jpn., Assoc. Mineral. Petrol, Econ. Geol., Min. Soc. Jpn., No. 22 (in Japanese). 

Togashi, Y. and Shibata, K. (1984) K-Ar age for alumite-bearing rock from the Iwato gold deposit, Kagoshima Prefecture, southern Japan. Mining Geology, 34, 281-286 (in Japanese). 

Tsuboya, K. (1936) The geology and the ore deposits of the Tsugu gold mine, Aichi prefecture. J. Geol. Soc. Japan, 43, Ci-ll (in Japanese). 

Urashima, Y, Sato, M. and Sato, E. (1981) The Iwato gold ore deposits, Kagoshima Prefecture, Japan. Mining Geology Special Issue, 10, 1-14 (in Japanese). 

Watanabe, K. and Nagai, S. (1986) Regional aleration in and around the Rendaiji gold-silver ore deposits, Shizuoka Prefecture. J. Miner. Soc. Jpn., 17, 69-74 (in Japanese with English abst.). 

Fig. 2.23 shows the distributions of major geothermal systems and epithermal gold deposits of Japanese Islands. It is interesting to note that their distributions are similar and they are distributed close to the volcanic front. 

During the middle Miocene, Kuroko deposits, polymetallic vein-type deposits, gold-quartz vein-type deposits and Sb and Hg vein-type deposits were formed (see sections 1.3 and 1.6). Many vein-type deposits were formed not only in and nearby the Japanese Islands, but also at middle Miocene in northwest USA (Basin and Range Lipman, 1982), and elsewhere in the circum-Pacific regions (e.g., Peru). It is probable that large amounts of CO2 effused into the atmosphere from hydrothermal solution associated with this widespread mineralization and volcanic gas from subduction zones, causing an increase in temperature. 

Oguchi, H. (1983), Japanese shakudo, its history, properties and production from gold containing alloys, Gold Bull. 16, 125-132. 

The Order of the Sacred Treasure, Gold Rays with Neck Ribbon (Japanese Government, posthumous award)... 

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