Analyses of Mineral Composition and Grain Size of the Sandstones from the Daedong Group

대동층군(大同層群) 사암(砂岩)의 광물성분(鑛物成分)과 입도분석(粒度分析)에 관(關)하여

  • Yu, Kang Min (Department of Geology, College of Science, Yonsei University Seoul)
  • 유강민 (연세대학교 이과대학 지질학과)
  • Published : 1985.06.30

Abstract

Mineral composition and grain size analyses of the sandstone from the Early Jurassic Daedong Group distributed in Mungyeong, Daecheon, Kimpo and Yeoncheon areas were made for the study of provenances and depositional environments. The most of the analyses are obtained from Mungyeong area, with some preliminarly works from Daecheon, Kimpo and Yeoncheon areas. All sandstones from the study area are characterized by high content of quartz ranging from 59.8 to 87.2 percent of total constituents. Many of quartz which has rounded dust ring seems to come from aeolian sediments. Content of feldspar is very low except Daecheon area where it ranges from 1.8 to 10.0 percent. Sandstones from Mungyeong, Kimpo and Yeoncheon areas are classified as quartz and quartzose arenite/wacke, while those from Daecheon area are classified as quartzose and lithic arenite/wacke. According to the character of the sandstones, provenance could be quartzose sandstone and quartzite. Results of grain size analysis of C-M and sorting versus skewness suggest that depositional environment seems to be fluvial, while log-probability curve pattern lacustrine environment. It is hard to derive a definite conclusion of sedimentary environment by the grain size analysis.

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Acknowledgement

Supported by : Korean Federation of Science and Technology societies