Geothermometrical Studies of Fluorite Deposits with special reference to the Studies of Fluorites from the Wolaksan area and Cheonil Mine, Chungcheongbuk-Do

형석광상(螢石鑛床)의 지질온도측정(地質溫度測定) 연구(硏究) 특(特)히 충북(忠北) 월악산지대(月岳山地帶) 및 천일광산(天一鑛山) 형석(螢石)의 연구(硏究)를 중심(中心)으로

Temperature environments of the formation of fluorite deposits in the Wolaksan area and the Cheonil Mine, Chungcheongbuk-Do are presented and interpreted in brief. These deposits occur more or less near the contact zone between the Paleozoic limestone formations and the Cretaceous biotite granites as a number of hydrothermal veins or replacement deposits. The homogenization temperatures of fluorite crystals from the Wolaksan area fall within the narrow range of $149{\sim}167^{\circ}C$, of which lower limit is quite high, while those of the Cheonil Mine show wide range of $126{\sim}177^{\circ}C$, which indicates much lower mean temperature of formation. If the possible correction for pressure, which may not exceed $+30^{\circ}C$ as the depth of the deposits was 1.5km, were applied, the possible highest value of the true formation temperatures of fluorites in both area might be reached to around $200^{\circ}C$ that means these deposits were formed as a series of early products of the epithermal stage of hydrothermal processes.