충청북도 보은군 마노면지역에서 옥천변성대의 지질구조 해석 = Structural Analysis of the Ogcheon metamorphic zone in the Mano-myeon area, Boeun-gun, Chungcheongbuk-do, Korea

다국어 초록 (Multilingual Abstract)

In the Mano-myeon area which is located at the central-south part of the Ogcheon belt, Korea, Cheongsan shear zone is developed and boundary fault of Ogcheon metamorphic zone and Taebaksan zone passes, and main constituent rocks of Ogcheon belt [Ogcheon Supergroup of age unknown and Paleozoic metamorphic rocks (Joseon Supergroup and Pyeongan Group) and Mesozoic granitoid (Baegnok, Cheongsan and Boeun granites)] are distributed. This study is to grasp the geological structure of Ogcheon belt in the Mano-myeon area by analysing the rock-structure of its constituent rocks. It indicates that the geological structure of this area was formed at least by three phases of deformation since the Pyeongan Group is deposited. The structural features of these three phases of deformation and their relative occurrence times are as follows. The first phase deformation (D1) formed isoclinal fold (F1) with axial surface (S1) generally striking ENE and moderately dipping north, and stretching lineation (L1) which gently plunges ENE or WSW on the S1 foliation. D1 deformation, which occurred under NNW-SSE compression related to the Cheongsan ductile shearing of dextral strike-slip (top-to-the ENE or NE shearing on the S1 foliation) after the intrusion of the Baegnok and Cheongsan granites, is closely connected with Songrim orogeny. The second phase deformation (D2) formed Z-shaped asymmetric fold (F2) of SE-vergence or S-vergence. Generally, its axial surface (S2) strikes ENE and gently dips north, and its fold axis (L2) gently plunges ENE or WSW. D2 deformation, which occurred under NNW-SSE compression just before the intrusion of the Boeun granite, is closely connected with Daebo orogeny. The third phase deformation (D3) formed asymmetric conjugate kink fold and open fold. Generally, their axial surfaces (S3) strike both NNW and NE and moderately or steeply dip, and their fold axes (L3) moderately plunge NNW. D3 deformation, which occurred under ENE-WSW compression after the intrusion of the Boeun granite, partly rearranged the E-W orientation of pre-D3 structural elements, which occurred under the same NNW-SSE compressional field, into the N-S orientation.

목차 (Table of Contents)

• 요약 =Ⅰ
• 목차 = Ⅱ
• List of figure = Ⅲ
• 제1장 서언 = 1
• 제2장 연구방법 = 5
• 제3장 지질개요 = 8
• 제4장 암석기재 = 12
• 제5장 변형작용사 = 19
• 제1절 첫 번째(D1) 변형 = 20
• Ⅰ. 평안누층군 = 20
• Ⅱ. 청산 화강암 = 31
• 제 2 절 두 번째(D2) 변형 = 33
• Ⅰ. 평안누층군 = 33
• 제 3 절 세 번째(D3) 변형 = 43
• Ⅰ. 평안누층군 = 43
• 제6장 해석 및 토의 = 50
• 제7장 결언 = 58
• 참고문헌 = 63
• 영문초록 = 67