人形峠ウラン鉱山，中津河鉱床南部鉱体の微量元素について

The Nakatsugo Deposits are the main deposits of the Ningyo Toge Mine which is located in the northern part of Okayama Prefecture. Nakatsugo Deposits consists of the two main ore body, namely, Nanbu Kotai (southern ore body) and Hon Kotai (main ore body). Nanbu Kotai is occupied mostly by the unoxidized zone and high grade ores containing ningyoite (n% U) are widely found in the basal conglomerates. Minor elements in the common rocks such as basal granites, conglomerates, sandstones, dikes, and shales as well as the uraniferous ores were determined quantatively by fluorescent X-ray spectrometric analysis (for U, Zr, Y, Sr, As, and Fe) and spectrophotometric analysis (for Ni and Co). As the results of this study, it is found that the uraniferous ores are characterised by extremely high contents of Zr, Y, Sr, and As, which show positive and linear correlation with the U contents. It is confirmed that As is concentrated in pyrite which is usually associated with the uraniferous ores. Elements such as Ni and Co are slightly concentrated both in the uraniferous ores and andesite dikes. This fact may suggest some genetic relationship among them. However, it does not seem to be plausible to draw any definite conclusion on the origin of the uranium deposits from these relationships. As to the minor element distribution in common rocks, no systematic variation was found except for the rock samples closely associated with the ore deposits.

原著論文 (Original Paper)