옥천대와 경기육괴의 경계부, 주천 지역의 지질구조 = Geological Structures of Jucheon Area, Contact Area between Ogcheon Belt and Gyeonggi Massif

다국어 초록 (Multilingual Abstract)

The Songbong Formation (so-called Bangrim Group), correated to the lower part of Choseon Supergroup, unconformably overlies the Precambrian Gyeonggi massif at northeastem tip of the Ogcheon belt The contact relationship between the Choseon Supergroup and the Yeongnam massif is also known as an unconformity at northeastem part of the Ogcheon belt. lt implies that the Gyeonggi and Yeongnam massifs were probably connected each other before the Early Paleozoic. Three deformational phases are recognized in the study area, The first phase is the north-northeastward ductile thrusting, which places Precambrian granite of the Gyeonggi massif over the Paleozoic rocks of the Ogcheon belt. The second phase is characterized by the southeastward thrusting and deformation partitioning along the Nuruhaji compartment fault. The third phase is the reactivation of the Nuruhaji Fault into dextral strike-slip fault with over a few kilometers displacement.

국문 초록 (Abstract)

옥천대의 북동변인 주천 지역에 분포하는 송봉층(소위 방림층군)은 선캠브리아 시대의 경기육괴 기반암위에 부정합 관계로 분포하며, 조선누층군의 하부 지층에 대비된다. 이것은 영남육괴와 조선누층군의 관계가 옥천대 남동변에서 역시 부정합이라는 사실과 함께 옥천대 양쪽 경계부의 기반암이 최소한 고생대 초에는 하나였을 것임을 의미한다. 주천 지역에서는 세 번의 변형작용이 인지된다. 첫 번째 변형작용에 의해서 선캠브리아 시대의 화강암이 연성전단대를 따라서 북북동 방향으로 옥천대의 고생대층 상위로 이동하였다. 두 번째 변형작용은 남동방향을 향한 충상단층운동과 이에 수반된 누루하지단층으로 특징 지워진다. 특히 누루하지단층을 경계로 하여 북동쪽 지괴와 남서쪽 지괴 사이에 변형작용 분리가 발생하였다. 세 번째 변형작용은 누루하지단층을 수 km의 변위를 갖는 우수향 주향이동단층으로 재활성시켰다.

참고문헌 (Reference)

1 Kim, J.H, "The Okdong Fault" 22 : 285-291, 1989

2 Yanai, S., "The Honam Shear Zone (South Korea): Deformation and tectonic implication in the Far East" University Tokyo 35 : 181-210, 1985

3 Ryoo, C.-R, "Tectonics in the contact zone between the Precambrian basement (Gyeonggi Massif) and the Paleozoic sedimentary cover (Okchon Belt), Korea" 59-64, 1997

4 Kihm, Y.H., "Structural characteristics of the central Ogcheon Belt, South Korea: orogen- parallel tectonic transport model" 22 : 41-57, 2003

5 Davis, G.H, "Structural Geology of Rocks and Regions" Wiley 776-, 1996

6 Lee, H.Y, "Sedimentological, stratigraphical and paleontological study on the Sambangsan Formation and its adjacent formations in the Yeongweol-Pyeongchang area, Kangweondo" 22 : 69-86, 1986

7 Ryoo, C.-R, "Rechérches tectoniques en Corée. Thèse de Dotorat" Universitéde Montpellier II 135-, 1995

8 Ree, J.-H, "Possible eastward extension of Chinese collision belt in South Korea: the Imjingang belt" 24 : 1071-1074, 1996

9 Kim, J.H., "Mesozoic tectonics in Korea" 13 : 251-265, 1996

10 Cho, M, "Highpressure amphibolite of the Imjingang belt in the Yeoncheon- Cheongok area" 4 : 1-19,

11 Son, C.M., "Geology of the Northwestern Part of Pyeongchang District, Gangweon-do, Korea" 7 : 143-152, 1971

12 Kobayashi, T, "Geology of South Korea with special reference to the limestone plateau of Kogendo. The Cambro-Ordovician Formations and the Faunas of South Chosen (Korea). part IV" Tokyo Univ 145-293, 1953

13 Hukasawa, T., "Geology of Heisho District, Kogendo, Tyoseon" 50 : 29-43, 1943

14 Kim, J.H., "Geology and Sr, Nd and Pb isotopic compositions of Precambrian granitoids in the Pyeongchang area, Korea" 33 : 27-35, 1997

15 Won, J.K., "Geological Report of the Shinlim Sheet (1:50,000)" Korea Institute of Energy and Resources 28-, 1974

16 Cheong, C.H, "Geological Report of the Pyeongchang-Yeongweol Sheet" Kore Institute of Energy and Resources 19-, 1979

17 Yoon, W.S., "Geologic structures and deformational sequence of the Jucheon-Yeongweol area, Mt. Taebaeg Region, Korea" Seoul National University 1994

18 Cluzel, D, "Geodynamics of the Ogcheon Belt (South Korea)" 183 : 41-56, 1990

19 Oh, C.W., "First Finding of Eclogite Facies Metamorphic Event in South Korea and Its Correlationwith the Dabie-Sulu Collision Belt in China" 113 : 226-232, 2005

20 Kwon, S, "Evidence for Permo-Triassic collision in Far East Asia: The Korean collisional orogen" 279 : 340-349, 2009

21 Chough, S.K, "Earth-Science Review" 52 : 175-235, 2000

22 Kim, J.H, "Characteristic of the so called Banglim Fault and structures of its adjacent area, Pyeongchang, Korea" 35 : 99-116, 1999

23 Yin, A, "An indentation model for the North and South China collision and the development of the Tan-Lu and Honam fault systems, Eastern Asia" 12 : 801-813, 1993