The process of formation of rare metal-bearing phosphates by hydrothermal alteration.

研究资料来自山口县、岛根县、佐贺县和鹿儿岛县。许多磷酸盐矿物是在山口县武町的日之丸中子矿中发现的。其中，在日本首次发现的有滑石、铁长石和goyazite。两者关系密切，钡和少量锶富集于戈长石中，只有锶存在于戈长石中。两种矿物均为等构造，但在热液蚀变条件下，两者之间不存在复杂的固溶体。戈长石和戈雅石不含稀土元素，尽管它们与等构造萤光石- (Ce)密切相关。在鹿儿岛县牧崎和静冈县古固附近蚀变带明矾岩中发现了含稀土的辉长石和木屋石。通过化学分析和背向散射电子图像观测，确定了热液蚀变过程中稀有金属的富集和阴离子的组合顺序。如阴离子的组合顺序为（PO_4） （PO_4）、（PO_4） （SO_4）、（SO_4） （SO_4）。

The studied materials were collected from Yamaguchi Prefecture, Shimane prefecture, Saga Prefecture, and Kagoshima Prefecture. Many phosphate minerals are recognized from the Hinomaru-Nako mine, Abu-cho, Yamaguchi Prefecture. Among them, trolleite, gorceixite and goyazite are firstly found in Japan. They are closely associated and barium and minor strontium are concentrated in gorceixite, only strontium is in goyazite. Though both minerals are isostructural, no complite solidsolution exists between them under the condition of hydrothermal alteration. Gorceixite and goyazite do not include REE in spite of their close association with isostructural florencite- (Ce). REE-bearing crandallite and woodhouseite are found in alunite rock from the alteration rigion around Makurazaki, Kagoshima Prefecture and Ugusu, Shizuoka Prefecture. The sequence of concentration of rare metal and assemblage of anions during the hydrothermal alteration is recognized under the chemical analyzes and observatoin of back-scattered electron images. For example, the assemblage of anions is (PO_4) (PO_4), (PO_4) (SO_4) and (SO_4) (SO_4) in order of stage of formation.