지구물리 (Journal of the Korean Geophysical Society)

한국지구물리·물리탐사학회 (Korean Society of Earth and Exploration Geophysicists)
권호 표지

남극반도 스미스섬 부근 대륙주변부의 탄성파 구조

Seismic Structures of the Continental Margin around Smith Island, antarctic Peninsula

  • 진영근 (한국해양연구원 부설 극지연구소/경북대학교) ;
  • 남상헌 (한국해양연구원 부설 극지연구소) ;
  • 이주한 (한국해양연구원 부설 극지연구소) ;
  • 홍종국 (한국해양연구원 부설 극지연구소) ;
  • 이덕기 (기상청) ;
  • 이종익 (한국해양연구원 부설 극지연구소)
  • 발행 : 20060000
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

남극반도 북부 남셰틀랜드군도 남서부에 위치한 스미스섬 부근 대륙주변부에서 작성된 탄성파 단면도를 분석하여 이 지역의 퇴적층의 분포, 퇴적작용, 대륙붕 형성과정 및 지체구조 발달사를 고찰하였다. 연구지역은 히어로 파쇄대의 대륙쪽 연장선에 위치한 스미스섬을 경계로 지체구조적으로 매우 상이한 두 지역으로 나눌 수 있다. 스미스섬의 남서쪽 지역은 확장중심-해구이 충돌 결과로 형성된 비활동성 대륙주변부가 전개되며, 북동쪽 지역은확장중심과 해구의 구조가 해양에 남아 있는 활동성 대륙주변부가 발달해 있다. 전체적으로 스미스섬을 경계로 북동쪽 지역에서는 두꺼운 퇴적층을 가진 대륙붕 퇴적층지역과 전호분지가 발달되어 있으며, 상대적으로 넓은 대륙사면과 뚜렷한 형태의 해구를 볼 수 있다. 남서쪽 지역은 가파르고 좁은 대륙사면과 국부적으로 형성된 대륙붕분지들이 특징적으로 나타난다. 또한 남서쪽 지역에는 이미 섭입된 확장중심의 열적효과(thermal effect)의 결과로 형성된 것으로 해석되는 기반암 상승부가 대륙붕의 중간부에 잘 발달되어 있다. 기반암 상승부는 스미스섬의 북동쪽을 연장되어 히어로파쇄대를 따라 형성된 경계부가 뚜렷한 지체구조 경계를 형성하지는 않는 것으로 해석된다.

Using seismic profiles obtained in the Antarctic Peninsula continental margin around Smith Island located at the southwestern end of the South Shetland Islands, we investigated sediments distribution, sedimentation, continental shelf formation, and tectonic evolution history. The study area is a very unique area that has two tectonic provinces with a tectonic boundary near Smith Island just the landward projection of the Hero Fracture Zone (HFZ). To the southwest of the Island, the margin became inactive margin after the collision of the ridge crest of the Antarctic-Phoenix ridge and trench, whereas to the northeast the margin is still apparently active margin with the spreading center and trench morphology in the sea. Generally the northeastern margin has the shelf sedimentary basins wth thick sedimentary layers, well-developed forearc basin, broad continental slope and distinct trench morphology, and the southwestern margin is characterized by steep and narrow continental slope and localized shelf basins. the mid-shelf basement high structures are distinct in the southwestern margin, which are thought to be formed by thermal effect caused by the subducted spreading centers. The high is observed in the area just northeast of the Island, implying that the tectonic boundary along the landward projection of the HFZ is not sharply defined.

키워드

참고문헌

  1. 남상헌외 20인, 1997, 97 남극 해저지질 조사사업 보고서, 한국 해양연구소 보고서, 해양수산부, 346 p
  2. Ashcroft, W.A., 1972, Crustal structure of the South Shetland Islands and Bransfield Strait, British Antarctic Survey Scientific Reports, No. 66, 43 pp
  3. Barker, P.F,. 1976, The tectonic framework of Cenozoic volcanixm in the Scotia Sea region, a review, In: Gonzalez-Ferran, O. (ed), Andean and Antarctic Volcanology Problem, International Association of Volcanology and Chemistry of the Earth's Interior, Rome, pp. 330-346
  4. Barker, P.F., 1982, The Cenozoic subduction history of the Pacific margin of the Antarctic Peninsula: Ridge cresttrench interactions, J. Geol. Soc. London, 139, 787- 801 https://doi.org/10.1144/gsjgs.139.6.0787
  5. Barker, P.F., 1995, The proximal marine sediment record of antarctic climate since the late Miocene, In: Cooper, A.K., Barker, P.F. and Brancolini G. (eds.), Antarctic Research Series. Geology and Seismic Stratigraphy of the Antarctic Margin. American Geophysical Union, Washington, D.C., p. 24-57
  6. Barker, P.F., and Dalziel, I.W.D., 1983, Progress in geodynamics in the Scotia Arc region, In: Cabre R. (ed.), Geodynamics of the eastern Pacific region, Caribbean and Scotia Arcs, AGU, 137-170
  7. Bart, P.J, and Anderson, J.B., 1995, Seismic record of glacial events affecting the pacific margin og the northwestern Antarctic Peninsual, In: Cooper, A.K., Barker, P.F., and Brancolini, G. (eds), Geology and seismic stratigraphy of the Antarctic Margin, Antarctic Research Series vol. 68, AGU, Washington, pp. 74-95
  8. Gamboa, L.A.P., and Maldonado, R., 1990, Geophysical investigations in the Bransfield Strait and in the Bellingshausen Sea-Antarctica, In: St. John, B. (ed.), Antarctica as an exploration frontier-hydrocarbon potential, geology, and hazards, American Association of Petroleum Geologists Studies in Geology No. 31, 127-141
  9. Grikurov, G.E., Krylov A.y., Polyakov M.M. and Tsovbun, Y.N., 1970, Age of rocks from the northern part of the Antarctic Peninsula and the South Shetland Islands (from data of the potassium-argon method) (in Russia), Inf. Byull. Sov Antarkt. Eksped., 80, 30-34. (Inf. Bull. Sov. Antarct. Exped., Engl. Transl., 8, 61-63, 1970)
  10. Grunow, A.M., Kent, D.V. and Dalziel, I.W.D., 1991, New paleomagnetic data from Thurston Island: implications for the tectonics of West Antarctica and Weddell Sea opening, J. Geophys. Res., 96, 17935-17954 https://doi.org/10.1029/91JB01507
  11. Grunow, A.M., Dalziel, I.W.D., Harrison, T.M. and Heizler, M.T., 1992, Structural geology and geochronology of subduction complexes along the margin of Gondwanaland: New data from the Antarctic Peninsula and southernmost Andes, Geol. Soc. Am. Bull., 104, 1497-1514 https://doi.org/10.1130/0016-7606(1992)104<1497:SGAGOS>2.3.CO;2
  12. Henriet, J.P., Meissner, R., Miller, H., and the GRAPE Team, 1992, Active margin processes along the Antarctic Peninsula, Tectonophysics, 201, 229-253 https://doi.org/10.1016/0040-1951(92)90235-X
  13. Herron, E.M. and Tucholke, B.E., 1976, Seafloor spreading patterns and basement structure in the Southeastern Pacific, Initial REp. Deep Sea Drill. Proj., 35, 263-278
  14. Jeffers, J.D., Anderson, J.B., and Lawver L.A., 1991, Evolution of the Bransfield basin, Antarctic Peninsula, In: Thomson, M.R.A., Crame, J.A., and Thomson J.W. (eds.), Geological Evolution of Antarctica, Cambridge University Press, Cambridge, 481-485
  15. Jin, Y. K. and Kim, Y., 1996, Tectonic implication of the Crustal Structure in the South Shetland Trench, Antarctic Peninsula, J. Geol. Soc. Korea, 32, 146-161
  16. Jin, Y.K., Larter, R.D., Kim, Y., Nam, S.H. and Kim, K.J., 2002, Post-subduction margin structures along Boyd Strait, Antarctic Peninsula. Tectonophysics, 346, 187-200 https://doi.org/10.1016/S0040-1951(01)00281-5
  17. Kim, Y, Kim, H.-S., Larter. R.D., Camerlenghi, A., Gamboa, L.A.P. and Rudowski, S., 1995, Tectonic deformation in the upper crust and sediments at the South Shetland Trench. In: Cooper, A.K., Barker, P.F. and Branco1ini G. (eds.), Antarctic Research Series. Geology and Seismic Stratigraphy of the Antarctic Margin. American Geophysical Union, Washington, D.C., p. 157-166
  18. Larter, R.D., and Barker, P.F., 1989, Seismic stratigrapy of Antarctic Peninsula Pacific margin; a record of Pliocene-Pleistocene ice volume and paleoclimate, Geology, 17, 73-1734
  19. Larter, R.D., and Barker, F., 1991, Effects of ridge crest-trench interaction on Antarctic-Phoenix SP reading: Forces on a young subduction plate. J, Geophys. Res., 96, 19587-19607
  20. Maldonado, A, Larter, R.D., and Aldaya, F., 1994, Forearc tectonic evolution of the South Shetland Margin, Antarctic Peninsula, Tectonics, 13, 1345-1370 https://doi.org/10.1029/94TC01352
  21. Pankhusrst, R.J and Smellie, J.L., 1983, K-Ar geochronology of the South Shetland Islands, Lesser Antarctica: Apparent lateral migration of Jurassic to Quaternary island arc volcanism, Earth Planet. Sci. Lett., 66, 214-222 https://doi.org/10.1016/0012-821X(83)90137-1
  22. Pankhurst, R.J., 1982, K-Sr geochronolgy of Graham Land, Antarctica, J Soc. Geol. London, 139, 701-711 https://doi.org/10.1144/gsjgs.139.6.0701
  23. Parra, J.C., Gonzalez-Ferran, O., and Bannister, J., 1984, Aeromagnetic survey over the South Shetland Islands, Bransfield Strait and part of the Antarctic Peninsula, Rev. Geol. Chile, 23, 3-20
  24. Pelayo, A.M., and Wiens, D.A., 1989, Seismotectonics and relative plate motions in the Scotia Sea region, J Geophys. Res., 94, 7293-7320 https://doi.org/10.1029/JB094iB06p07293
  25. Prosser, S., 1993, Rift-related linked depositional systems and their seismic expression, In: Williams, G. D. and Dobb, A. (eds.), Tectonics and Seismic Sequence Stratigraphy, Geological Society Special Publication, 71, 35-66 https://doi.org/10.1144/GSL.SP.1993.071.01.03
  26. Roach, R.J., 1978, The nature of back arc extension in Bransfield Strait [abstract], Geophys. J. R. Astron. Soc., 53, 165
  27. Smellie, J.L. and Clarkson, P.D., 1975, Evidence for pre-Jurrassic subduction in western Antarctica, Nature, 258, 701-702 https://doi.org/10.1038/258701a0
  28. Storey, B.C. and Garrett, S.W., 1985, Crustal growth of the Antarctic peninsula by accretion, magmatism and extension, Gelogical magazine, 122, 5-14 https://doi.org/10.1017/S0016756800034038
  29. Tinivella, U. Lodolo, E., Carnerlenghi, A. and Boehm, G., 1998, Seismic tomography study of a bottom simulating reflector off the South Shetland Islands (antarctica). In: Henriet, J. -P and Mienert, J. (eds.), Gas Hydrates: Relevance to World Margin Stability and Climete Change, Geological Society Special Publication, 137, 141-151