Movement History of Faults Considered from the Geometric and Kinematic Characteristics of Fracture System in Gilan-cheongsong Area, Gyeongsang Basin, Korea

경상분지 길안-청송 지역에서 단열계의 기하학적.운동학적 특성으로부터 고찰된 단층운동사

  • Lee, Deok-Seon (Department of Earth and Environmental Sciences, Andong National University) ;
  • Kang, Ji-Hoon (Department of Earth and Environmental Sciences, Andong National University)
  • 이덕선 (안동대학교 지구환경과학과) ;
  • 강지훈 (안동대학교 지구환경과학과)
  • Published : 2009.12.31

Abstract

The Gilan-Cheongsong area, which is in contact with Yeongyang and Uiseong Blocks of Gyeongsang Basin, Korea, consists of Precambrian metamorphic rocks, Triassic Cheongsong granite, Cretaceous sedimentary rocks(Iljik, Hupyeongdong, Jeomgok Formations), and Cretaceous igneous rocks(andesite, quartz porphyry, felsite). In this area are developed faults trending in (W)NW, NNW, ENE, NS, (N)NE directions which are representative in the Gyeongsang Basin. We analyzed the geometric and kinematic characteristics of fracture systems to inquire into movement history and sense of these faults in this area. This study suggests that these faults were mainly strike-slip movement. The orientations of fracture sets show ENE, NNW, (W)NW, (N)NE, NS in descending order of frequency. Their prolongation presents (W)NW, NNW, ENE, (N)NE, NS in descending order of predominance, and also agrees with that of faults in this area. The development sequence and movement sense of fracture sets are summarized as follows; (1) (W)NW: dextral shearing $\rightarrow$ (2) (W)NW and NNW: conjugate shearing(the former: dextral, the latter: sinistral) $\rightarrow$ (3) NNW: dextral shearing $\rightarrow$ (4) (W)NW: sinistral shearing $\rightarrow$ (5) ENE: dextral shearing $\rightarrow$ (6) ENE and NS: conjugate shearing(the former: sinistral, the latter: dextral) $\rightarrow$ (7) (N)NE: sinistral shearing, and this result is closely associated with the development sequence and movement sense of faults developed in this area.

경상분지 영양지괴와 의성지괴가 접하는 길안-청송 지역은 선캠브리아기 변성암류, 트라이아스기 청송 화강암, 백악기 퇴적암류(일직층, 후평동층, 점곡층), 그리고 백악기 화성암류(안산암, 석영반암, 규장암) 등으로 구성되어 있으며, (서)북서, 북북서, 동북동, 남북, (북)북동 등 경상분지를 대표하는 다양한 방향의 단층들이 발달한다. 본 연구는 이들 단층의 발달사 및 운동성을 조사하기 위해 길안-청송 지역에 발달하는 단열계의 기하학적 운동학적 특성을 파악하였다. 그 결과, 연구지역내 발달하는 단층들의 운동성은 대부분 주향이 동성으로 인지되며, 방향성별 단열조의 출현빈도는 동북동, 북북서, (서)북서, (북)북동, 남북 등의 방향 순으로 높게 나타난다. 방향성별 단열조의 연장성은 (서)북서, 북북서, 동북동, (북)북동, 남북 등의 방향 순으로 우세하게 나타나고, 이러한 우세 방향성은 단층들의 연장성과 거의 일치한다. 방향성별 단열조의 발달사 및 운동성은 (1) (서)북서 방향 단열조의 우수향 전단단열운동 $\rightarrow$ (2) (서)북서 방향과 북북서 방향 단열조의 공액성 전단단열운동(전자: 우수향, 후자: 좌수향) $\rightarrow$ (3) 북북서 방향 단열조의 우수향 전단단열운동 $\rightarrow$ (4) (서) 북서 방향 단열조의 좌수향 전단단열운동 $\rightarrow$ (5) 동북동 방향 단열조의 우수향 전단단열운동 $\rightarrow$ (6) 동북동 방향과 남북 방향 단열조의 공액성 전단단열운동(전자: 좌수향, 후자: 우수향) $\rightarrow$ (7) (북)북동 방향 단열조의 좌수향 전단단열운동 등으로 요약되고, 이러한 연구결과는 길안-청송 지역에 발달하는 단층들의 발달사 및 운동성과 밀접한 관련성 있다.

Keywords

References

  1. 강지훈, 류충렬, 2006, 경상분지 의성지괴 길안면지역에서 청송화강암의 단열 발달사 및 운동성에 대한 기하학적 해석. 암석학회지, 15, 180-193
  2. 이덕선, 2009, 길안-청송 지역의 지질구조: 단열계를 이용한 단층 특성 연구를 중심으로. 안동대학교 석사 학위논문, 13-19p
  3. 이병주, 황재하, 1997, 경상분지 북동부에서의 가음단층과 양산단층의 관계. 지질학회지, 33, 1-8
  4. 이홍규, 홍승호, 1973, 한국지질도(1:50,000), 청송 지질도폭 및 설명서. 국립 지질 광물연구소, 19p
  5. 장기홍, 1975, 한반도 동남부의 백악계 층서. 지질학회지, 11, 1-23
  6. 장기홍, 1977, 경상분지 상부중생계의 층서퇴적 및 지구조. 지질학회지, 13, 76-90
  7. 장기홍, 고인석, 박희인, 지정만, 김항묵, 1978, 한국지질도(1:50,000), 천지 지질도폭 및 설명서. 자원개발연구소, 20p
  8. 좌용주, 김종선, 김건기, 2005, 우리나라 트라이아스기 화강암의 스위트/슈퍼스위트 분류. 암석학회지, 14, 226-236
  9. 최위찬, 김규봉, 홍승호, 이병주, 황재하, 박기화, 황상기, 최범영, 송교영, 진명식, 1995, 한국지질도 1:1,000,000. 한국자원연구소, 성지문화사
  10. Chang, K.H., 1975, Cretaceous Stratigraphy of Southeast Korea. Journal of the Geological Society of Korea, 11, 1-23
  11. Cheong, C.-S., Kwon, S.-T. and Sagong, H., 2002, Geochemical and Sr-Nd-Pb isotopic investigation of Triassic granitoids and basement rocks in the northern Gyeongsang Basin, Korea: Implications for the young basement in the East Asian continental margin. The Island Arc, 11, 25-44 https://doi.org/10.1046/j.1440-1738.2002.00356.x
  12. Choi, P.Y., Lee, S.R., Choi, H.I., Hwang, J.H., Kwon, S.K., Ko, I.S. and An, G.O., 2002, Movement history of the Andong Fault System : Geometric and tectonic approaches. Journal of Geosciences, 6, 91-102 https://doi.org/10.1007/BF03028280
  13. Cooke, M.L., 1997, Fracture localization along faults with spatially varying friction. Journal of Geophysical Research, 1002, 22425-22434
  14. Cruikshank, K.M., Zhao, G. and Johnson, A.M., 1991, Analysis of minor fractures asociated with joints and faulted joints. Journal of Structural Geology, 13, 865-886 https://doi.org/10.1016/0191-8141(91)90083-U
  15. Dunne, W.M. and Narth, C.P., 1990, Orthogonal fracture system at the limits of thrusting: an example from southwestern Wales. Journal of Structural Geology, 12, 207-215 https://doi.org/10.1016/0191-8141(90)90005-J
  16. Dyer, R., 1988, Using joint interactions to estimate paleostress ratios. Journal of Structural Geology, 10, 685-699 https://doi.org/10.1016/0191-8141(88)90076-4
  17. Engelder, T. and Gross, M.R., 1993, Curving cross joints and the lithospheric stress field in eastern North America Geology. 21, 817-820 https://doi.org/10.1130/0091-7613(1993)021<0817:CCJATL>2.3.CO;2
  18. Eyal, Y., Gross, M.R., Engelder, T. and Becker, A., 2001, Joint development during fluctuation of the regional stress field in southern Israel. Journal of Structural Geology, 23, 279-296 https://doi.org/10.1016/S0191-8141(00)00096-1
  19. Hancock, P.L., 1985, Brittle microtectonics: principles and practice. Journal of Structural Geology, 7, 437-457 https://doi.org/10.1016/0191-8141(85)90048-3
  20. Hancock, P.L., Al Kadhi, A. and Sha'at, N.A., 1984, Regional joint sets in the Arabian Platform as indicators of intraplate processes. Tectonics, 3, 27-43 https://doi.org/10.1029/TC003i001p00027
  21. Martel, S.J., 1990, Formation of compound strike-slip fault zones, Mount Abbot Quadrangle, California. Journal of Structural Geology, 12, 869-882 https://doi.org/10.1016/0191-8141(90)90060-C
  22. Martel, S.J. and Boger, W.A., 1998, Geometry and mechanics of secondary fracturing around small three-dimensional faults in granitic rock. Journal of Geophysical Research, 103, 21299-21314 https://doi.org/10.1029/98JB01393
  23. Martel, S.J., Pollard, D.D. and Segall, P., 1988, Development of simple strike-slip fault zones, Mount Abbot quadrangle, Sierra Nevada, California. Geological Society of America Bulletin. 100, 1451-1465 https://doi.org/10.1130/0016-7606(1988)100<1451:DOSSSF>2.3.CO;2
  24. Mollema, P.N. and Antonellini, M., 1999, Development of strike-slip faults in the dolomites of the sella Group, Northern Italy. Journal of Structural Geology, 21, 273-292 https://doi.org/10.1016/S0191-8141(98)00121-7
  25. Peacock, D.C.P., 2001, The temporal relationship between joints and faults. Journal of Structural Geology, 23, 329-341 https://doi.org/10.1016/S0191-8141(00)00099-7
  26. Petit, J.-P., 1988, Can natural fractures propagate under mode II condition?. Tectonics, 7, 1243-1256 https://doi.org/10.1029/TC007i006p01243
  27. Pollard, D.D. and Aydin, A., 1988, Progress in understanding jointing over the past century. Geological Society of America Bulletin, 100, 1181-1204 https://doi.org/10.1130/0016-7606(1988)100<1181:PIUJOT>2.3.CO;2
  28. Rawnsley, K.D., Rives, T., Petit, J.P., Hencher, S.R. and Lumsden, A.C., 1992, Joint development in perturbed stress fields near faults. Journal of Structural Geology, 14, 939-951 https://doi.org/10.1016/0191-8141(92)90025-R
  29. Rawnsley, K.D., Peacock, D.C.P., Rives, T. and Petit, J.P., 1998, Jointing in the Mesozoic sediments around the Bristol Channel Basin. Journal of Structural Geology, 20, 1641-1661 https://doi.org/10.1016/S0191-8141(98)00070-4
  30. Reches, Z. and Lockner, D.A., 1994, Nucleation and growth of faults in brittle rocks. Journal of Geophysical Research, 99, 18159-18174 https://doi.org/10.1029/94JB00115
  31. Renshaw, C.E. and Pollard, D.D., 1995, An experimentally verified criterion of propagation across unbounded frictional interfaces in brittle, linear clastic materials. International Journal of Rock Mechanics and Mining Sciences and Geomechanics, Abstracts 32, 237-249 https://doi.org/10.1016/0148-9062(94)00037-4
  32. Sagong, H., Kwon, S.-T. and Ree, J.-H., 2005, Mesozoic episodic magmatism in South Korea and its tectonic implication. Tectonics, 24, TC5002, doi:10.1029/2004TC 001720
  33. Wilkins, S.J., Gross, M.R., Wacker, M., Eyal, Y. and Engelder, T., 2001, Faulted joints: kinematics, displacement-length scaling relations and criteria for their identification. Journal of Structural Geology, 23, 315-327 https://doi.org/10.1016/S0191-8141(00)00098-5
  34. Willemse, E.J.M. and Pollard, D.D., 1998, On the orientation and patterns of wing cracks and solution surfaces at the tips of a sliding flaw or fault. Journal of Geophysical Research, 103, 2427-2438 https://doi.org/10.1029/97JB01587