山梨県乙女鉱床末広脈における鉱化作用
1995 年 45 巻 250 号 p. 111-120
詳細
1995 年 45 巻 250 号 p. 111-120
Metallic mineralization in the Suehiro vein and its neighbouring veins of the Otome deposit was described. The metallic minerals of the Suehiro vein and its neighbouring veins are ferberite, pyrrhotite, less pyrite, chalcopyrite, sphalerite, molybdenite 2H, goethite, arsenopyrite, cubanite, Ag, Sb-bearing cosalite, bismuthinite, native bismuth, ingodite, Bi-bearing boulangerite, izoklakeite etc.
The mineralization sequence at Otome can be divided into three stages, based on microscopic observation, EPM analyses and fluid inclusion data: Stage I (W mineralization), Stage II (sulphides and sulphosalts), and Stage III (hematite and goethite). Further, the stage II is subdivided into three substages. The fluid inclusion homogenization temperatures ranged from 350°to 250°C for stage I, from 330° to 150°C for stage II and lower than 150°C for stage III.
Temperatures and sulfur activities of stage II mineralization at Otome are estimated as 330° to 150°C, and -11 to -20 in log aS2 (atm.), based on the FeS contents of sphalerite, mineral assemblages and fluid inclusion data.
