Chemistry and Occurrences of Native Tellurium from Epithermal Gold Deposits in Japan
スポンサーリンク
概要
- 論文の詳細を見る
The chemistry and mode of occurrences of native tellurium in the epithermal gold ores from Teine, Kobetsuzawa, Mutsu, Kawazu, Suzaki and Iriki in Japan are examined. Mineral assemblages in contact with native tellurium are: quartz-sylvanite at Teine, quartz-hessite-sylvanite-tellurantimony at Kobetsuzawa, quartz at Mutsu, quartz-stutzite-hessite-sylvanite-tetradymite at Kawazu, quartz at Suzaki, and quartz-goldfieldite at Iriki. The peak patterns of XRD for native tellurium from these six ores are nearly identical to that of JCPDS 4–554. Their chemical compositions of Te range from 98.16 to 100.73 wt.%, showing nearly pure tellurium. Other elements detected are: Se of 0–0.85 and Cu of 0–0.74 at Teine, Sb of 0.45–0.47 and Se of 0.19–0.27 at Kawazu, Se of 0.22–1.11 and Sb of 0–0.49 at Suzaki, and Cu of 0.69–0.98, As of 0.22–0.28 and Bi of 0–0.22 wt.% at Iriki. No other elements are detected in the ores of Kobetsuzawa and Mutsu. The ranges of associated minor compositions are consistent with those of the experimental phase. The differences would be related to associate minerals. The mineral assemblages in these ores agree well with the previously proposed experimental phase relations in Au-Ag-Te ternary system for 120–280°C. The Suzaki ore has high Te-Au assemblage: from calaverite-sylvanite-krennerite via native tellurium to petzite, with changing mineralization stage, whereas the Kobetsuzawa and the Kawazu ores have high Te-Ag assemblage of tellurium-hessite, and native tellurium-stutzite-hessite-sylvanite, respectively. The Teine ore has intermediate assemblage of native tellurium-sylvanite. The mineral assemblages in the Au-Ag-Te system are related to the hydrothermal environment especially to the pH condition, i.e. Au rich assemblages under acidic and Ag rich assemblages under intermediate pH conditions, being supported by alteration mineral species. The other telluriferous epithermal gold deposits not in association with native tellurium such as Agawa, Date, Takeno, Chugu, Chitose, Sado and Kushikino are estimated to have been formed under higher pH conditions as adularia and calcite occur in these deposits. The pH-Eh diagram for aqueous tellurium species and tellurium minerals at 250°C indicates that the region of native tellurium occurs between those of aqueous telluride and tellurous species at lower pH, being consistent with their mineral assemblages in ores and alteration envelopes.
- Blackwell Publishingの論文
Blackwell Publishing | 論文
- Oncogenic role of miR-17-92 cluster in anaplastic thyroid cancer cells
- Genetics and Molecular Breeding in Lolium/Festuca
- Genetic and reproductive potential of spermatozoa of diploid and triploid males obtained from interspecific hybridization of Misgurnus anguillicaudatus female with M. mizolepis male
- Ploidy manipulation using diploid sperm in the loach, Misgurnus anguillicaudatus : a review
- Local balance of transforming growth factor-β1 secreted from cholangiocarcinoma cells and stromal-derived factor-1 secreted from stromal fibroblasts is a factor involved in invasion of cholangiocarcinoma