Fluid Inclusion Study of the Cretaceous Granite in the Yonghwa Area

용화(龍化)지역에 분포하는 백악기 화강암(化崗岩)에 포함된 유체포유물(流體包有物)에 관한 연구(硏究)

  • Youn, Seok-Tai (Dept. of Earth Science Education, Chonnam National Univ.) ;
  • Park, Hee-In (Dept. of Geological Science, Seoul National Univ.)
  • 윤석태 (전남대학교 지구과학교육과) ;
  • 박희인 (서울대학교 지질과학과)
  • Received : 1994.05.25
  • Published : 1994.06.30

Abstract

Fluid inclusions have been studied in phenocryst quartz from the Cretaceous porphyritic granite. Three main types of fluid inclusion were found: liquid-rich inclusion (I type), gas-rich inclusion (II type) and solid-bearing inclusions (III-A, III-B). The solid-bearing inclusions (III-A, B) represent the earliest trapped fluids. They have salinities between 63 and 67.5 wt.% equivalent NaCl. These are high saline inclusions containing NaCl and KCl daughter crystals. Homogenization temperature inferred from the fluid inclusion study ranges from 620 to $700^{\circ}C$. Type I and II inclusions were observed within the same fracture. This cause for these differences in degree of filling is evidence of boiling. Salinities of type I and II inclusions range from 10.24 wt.% to 13.44 wt.%, from 8.4 wt.% to 11.48 wt.% NaCl equivalent, respectively.

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