Economic and Environmental Geology (자원환경지질)

The Korean Society of Economic and Environmental Geology (대한자원환경지질학회)
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Comparative Analysis of the Joint Properties of Granite and Granitic Gneiss by Depth

심도에 따른 대전지역 화강암과 안동지역 편마암의 절리특성 비교분석

  • Choi, Junghae (Department of Earth Science Education, Kyungpook National University)
  • 최정해 (경북대학교 지구과학교육과)
  • Received : 2019.02.09
  • Accepted : 2019.03.01
  • Published : 2019.04.28
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Abstract

HLW (High Level Radioactive Waste) is one of the problems that must be solved in the countries that implement nuclear power generation. Most countries that are concerned about HLW treatment are considering complete isolation from human society by disposing them deep underground. For perfect isolation, understanding the characteristics of underground rocks is very important. In particular, understanding the characteristics of discontinuity as a path way is one of the first things in order to predict the movement of exposed nuclear species to the surface. In this study, we used 500m underground core samples obtained from granite and gneiss area. The purpose of this study is to understand the characteristics of the discontinuities in each rock type and to analyze the properties of the joints in the underground relative to the surrounding environment. For this purpose, the types of discontinuities were classified and the distribution of each discontinuity were analyzed through visual analysis of the each sample obtained at 500m underground. This study can be used as a basic data for understanding the properties of discontinuities in the rock of the survey area and it can be also used as an important data for understanding the distribution characteristics of discontinuities according to the rock types.

고준위방사성폐기물은 원자력 발전을 실시하는 국가에서는 반드시 해결해야 될 문제 가운데 하나이다. 대부분 고준위방사성폐기물 처리를 고민하는 나라에서는 지하 심부의 깊은 곳에 처분함으로써 인간사회로의 완벽한 격리를 고려하고 있다. 이러한 완벽한 격리를 위해서는 지하 심부에 위치하고 있는 암반의 특성을 파악하는 것이 매우 중요한 일이다. 특히 노출된 핵종이 이동을 통해 지표로 올라오는 것을 예측하기 위해서는 이동 경로가 되는 불연속의 특징을 이해하는 것은 무엇보다도 우선시 되어야 할 사항이다. 본 연구에서는 화강암과 편마암이 분포하는 지역에서 획득한 심부 500m 이하의 시료를 활용하여 각 암종별 분포하고 있는 불연속면의 특성을 이해하고 주변 환경과 고려하여 지하에 분포하고 있는 절리면의 특징을 분석하는데 그 목적이 있다. 이를 위해서 지하 500m에서 획득한 시료에 대한 육안분석을 통해 불연속면의 종류를 분류하고 각 불연속면의 분포특성을 분석하였다. 본 연구는 조사지역의 지하에 분포하고 있는 불연속면의 특징을 이해하는 기초자료로 활용될 수 있으며 추후 암종에 따른 불연속면의 분포 특징을 이해하는데 중요한 자료로 활용될 수 있을 것으로 기대한다.

Keywords

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Fig. 1. Geological map of granite area (Park et al., 1968).

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Fig. 2. Geological map of gneiss area (Kim et al., 1970, Chang et al., 1978).

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Fig. 3. Pictures of (a) granite core sample and (b) gneiss core sample.

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Fig. 4. Separation by dip angle of joint (yellow line : 60-90°, azure line : 30-60°, red line : 0-30°, blue line : sealed fracture).

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Fig. 5. Picture of calcite crystal in open fracture (in red circle).

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Fig. 6. SEM picture of pyrite and calcite crystal in open fracture.

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Fig. 7. Distribution of sealed and open fractures by depth for granite sample.

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Fig. 8. Distribution of sealed and open fractures by depth for gneiss sample.

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Fig. 9. Cumulation distribution of sealed and open fractured by depth for granite sample.

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Fig. 10. Cumulation distribution of sealed and open fractured by depth for gneiss sample.

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Fig. 11. Distribution of dip angle of open fracture by depth for granite sample.

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Fig. 12. Distribution of dip angle of open fracture by depth for gneiss sample.

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