암석학회지 (The Journal of the Petrological Society of Korea)

한국암석학회 (The Petrological Society of Korea)
권호 표지

평택-아산 알칼리 현무암의 Sr, Nd 및 Pb 동위원소 조성: 한반도 아래 맨틀의 대조적인 조성 경계에 대한 의미

Sr, Nd and Pb Isotopic Compositions of the Pyeongtaek-Asan Alkali Basalts: Implication to the Contrasting Compositional Boundary for the Mantle beneath Korean Peninsula

  • 박계헌 (부경대학교 환경.해양대학 환경지질과학과) ;
  • 정창식 (한국기초과학지원연구원 환경과학연구부) ;
  • 정연중 (한국기초과학지원연구원 환경과학연구부)
  • Park, Kye-Hun (Department of Environmental Geosciences, Pukyong National University) ;
  • Cheong, Chang-Sik (Division of Earth and Environmental Science, Korea Basic Science Institute) ;
  • Jeong, Youn-Joong (Division of Earth and Environmental Science, Korea Basic Science Institute)
  • 발행 : 2008.09.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

평택-아산 지역에 분포하는 신생대 현무암질 암석의 Sr, Nd, Pb 동위원소 조성은 한국의 다른 신생대 현무암들과 마찬가지로 중앙해령 현무암에 비해 상당히 부화된 값을 보여준다. 평택-아산 지역을 포함하는 한국의 신생대 현무암질 암석들 대부분은 제주도의 현무암들과는 달리 비교적 낮은 $^{206}Pb/^{204}Pb$ 성분을 갖는 부화맨틀과 결핍맨틀 사이의 혼합으로 설명될 수 있다. 반면에 제주도의 경우는 보다 높은 $^{206}Pb/^{204}Pb$ 성분을 갖는 부화맨틀과 결핍맨틀 사이의 혼합으로 설명된다. 이러한 경향성은 북동 중국과 남동중국의 신생대 현무암들에서도 유사한 부화맨틀 단성분의 차이가 발견되는 것과 연관지어 해석할 때는 한국의 중부지역과 남부지역 아래의 대륙암권 맨틀이 각각 북중국지괴 및 남중국지괴의 동측 연장부일 가능성을 나타낸다. 제주도 아래에 남중국 지괴와 같은 종류의 대륙암권맨틀의 성분이 나타나는 것은 중국의 대륙충돌대 위치와 관련한 만입모델로는 설명할 수 없다. 오히려 맨틀의 조성에서 뚜렷한 차이를 보이는 두 대륙의 봉합대가 한반도의 중부와 남부지역의 사이로 지나가며 그 위치는 평택-아산 지역보다 더 남쪽임을 시사한다. 대륙충돌대 경계의 위치가 과거의 연구에서 주로 주장되던 임진강대의 위치와는 상당히 다른 것은 맨틀 경계가 지각의 경계와 다를 가능성을 배제할 수 없다.

Sr, Nd, Pb isotopic compositions of the Cenozoic basaltic rocks distributed in Pyeongtaek-Asan area display significantly enriched values compared with mid-ocean ridge basalts just like other Cenozoic basalts of Korea. The isotopic compositions of most of the Cenozoic basaltic rocks of Korea including those from Pyeongtaek-Asan area can be explained as mixing between enriched mantle component with relatively low $^{206}Pb/^{204}Pb$ ratios and depleted mantle component. In contrast, Jejudo basalts can be explained as mixing between enriched mantle component with realtively higher $^{206}Pb/^{204}Pb$ ratios and depleted mantle componsnt. Combined with that very similar division of enriched mantle components is applied to the Cenozoic basalts of northeast China and southeast China, it is suggested that subcontinental lithospheric mantle of central and southern parts of Korea represents eastern extension of North China Block and South China Block respectively. The indentation model for the late Paleozoic to early Mesozoic continental collision of China contradicts to such an interpretation, because it cannot explain occurrence of subcontinental lithospheric mantle component of South China Block-affinity under the Jejudo area. Instead, it is more probable that suture zone of the two continental blocks crosses between central and southern Korea and its location is further south from the Pyeongtaek-Asan area. Such distinct location compared with Imjingal belt, supposedly collisional boundary suggested before, suggests that mantle boundary may not be coincide with crustal boundary for the continental collision.

키워드

참고문헌

  1. 김규한, 2000, 독도 알칼리 화산암류의 K-Ar 연대와 Nd- Sr 동위원소 조성. 지질학회지, 36, 313-324
  2. 김규한, 長尾敬介, 장형숙, 各野浩史, 정정인, 2002, 백령도 에 분포하는 알칼리 현무암과 맨틀 포획암의 Nd-Sr과 영 족기체 동위원소 조성. 자원환경지질, 35, 523-532
  3. 김동학, 최위찬, 오인섭, 1979, 한국지질도 아산도폭, 자원 개발연구소, 10p
  4. 박준범, 박계헌, 정창식, 1996, 제주도 화산암류의 Sr-Nd- Pb 동위원소 연구. 암석학회지, 5, 89-107
  5. 신홍자, 길영우, 진명식, 이석훈, 2006, 아산, 평택 지역 상 부맨틀 포획암의 암석학적 연구. 지질학회지, 42, 95-113
  6. Arakawa, Y., Saito, Y., and Amakawa, H., 2000, Crustal development of the Hida belt, Japan: Evidence from Nd- Sr isotopic and chemical characteristics of igneous and metamorphic rocks. Tectonophysics, 328, 183-204 https://doi.org/10.1016/S0040-1951(00)00183-9
  7. Basu, A.R., Wang, J.W., Huang, W.K., Xie, G.H., and Tatsumoto, M., 1991, Major element, REE, and Pb, Nd, and Sr isotopic geochemistry of Cenozoic volcanic rocks of eastern China: Implications for their origin from suboceanic- type mantle reservoirs. Earth Planet. Sci. Lett., 105, 149-169 https://doi.org/10.1016/0012-821X(91)90127-4
  8. Chang, E.Z., 1996, Collision orogene between north and south China and its eastern extension in the Korean Peninsula. Journal of Southeast Asian Earth Sciences, 13, 267-277 https://doi.org/10.1016/0743-9547(96)00033-5
  9. Choi, S.H., Jwa, Y.-J. and Lee, H.Y., 2001, Geothermal gradient of the upper mantle beneath Jeju Island, Korea: Evidence from mantle xenoliths. Island Arc, 10, 175-193 https://doi.org/10.1046/j.1440-1738.2001.00317.x
  10. Choi, S.H. and Kwon, S.-T., Mukasa, S.B., and Sagong, H., 2005, Sr-Nd-Pb isotope and trace element systematics of mantle xenoliths from Late Cenozoic alkaline lavas, South Korea. Chemical Geology, 221, 40-64 https://doi.org/10.1016/j.chemgeo.2005.04.008
  11. Choi, S.H., Lee, J.I., Park, C.-H. and Moutte, J., 2002, Geochemistry of peridotite xenoliths in alkali basalts from Jeju Island, Korea. Island Arc, 11, 221-235 https://doi.org/10.1046/j.1440-1738.2002.00367.x
  12. Choi, S.H., Mukasa, S.B., Kwon, S.-T., and Andronikov, A.V., 2006, Sr, Nd, Pb and Hf isotopic compositions of late Cenozoic alkali basalts in South Korea: evidence for mixing between the two dominant asthenospheric mantle domains between East Asia. Chemical Geology, 232, 134-151 https://doi.org/10.1016/j.chemgeo.2006.02.014
  13. Chung, S.L., 1999, Trace element and isotopic characteristics of Cenozoic basalts around the Tanlu Fault with implications for the east plate boundary between North and South China. J. Geol., 107, 301-312 https://doi.org/10.1086/314348
  14. Chung, S.L., Jahn, B.M., Chen, S.J., Lee, T. and Chen, CH., 1995, Miocene basalts in northwestern Taiwan: Evidence for EM-type mantle sources in the continental lithosphere. Geochim. Cosmochim. Acta, 59, 549-555 https://doi.org/10.1016/0016-7037(94)00360-X
  15. Chung, S.L., Sun, S.-S. and Crawford, A.J., 2001, Indian Ocean type convecting mantle underlies East Asia: A consequence of Gondwana break-up and reassembly? Western Pacific Earth Sci., 1, 1-18
  16. Chung, S.L., Sun, S.-s., Tu, K., Chen, C.-H. and Lee, C.Y., 1994, Late Cenozoic basaltic volcanism around the Taiwan Strait, SE China: Product of lithosphere-asthenosphere interaction during continental extension. Chem. Geol., 112, 1-20 https://doi.org/10.1016/0009-2541(94)90101-5
  17. Ernst, W.G. and Liou, J.G., 1995, Constrsting plate-tectonic styles of the Qinling-Dabie-Sulu and Franciscan metamorphic belts. Geology, 23, 353-356 https://doi.org/10.1130/0091-7613(1995)023<0353:CPTSOT>2.3.CO;2
  18. Fan, Q.C. and Hooper, P.R., 1991, The Cenozoic basaltic rocks of eastern China: Petrology and chemical composition. J. Petrol., 32, 765-810 https://doi.org/10.1093/petrology/32.4.765
  19. Flower, M.F.J., Zhang, M., Chen, C.Y., Tu, K. and Xie, G.H., 1992, Magmatism in the South China Basin, 2. Post-spreading Quaternary basalts from Hainan Island, south China. Chem. Geol., 97, 65-87 https://doi.org/10.1016/0009-2541(92)90136-S
  20. Hart, S.R., 1984, A large scale isotope anomaly in the southern hemisphere mantle. Nature, 309, 753-757 https://doi.org/10.1038/309753a0
  21. Hoang, N. and Flower, M.F.J., 1998, Petrogenesis of Cenozoic basalts from Vietnam: Implications for the origin of a "diffuse igneous province". J. Petrol., 39, 34-50
  22. Hoang, N., Flower, M.F.J. and Carlson, R.W., 1996, Major, trace element, and isotopic compositions of Vietnamese basalts: Interaction of hydrous EMI-rich asthenosphere with thinned Eurasian lithosphere. Geochim. Cosmochim. Acta, 60, 4329-4351 https://doi.org/10.1016/S0016-7037(96)00247-5
  23. Kim, K.H., Tanaka, T., Nagao, K. and Jang, S.K., 1999, Nd and Sr isotopes and K-Ar ages of the Ulreungdo alkali volcanic rocks in the East Sea, South Korea. Geochemical J., 33, 317-341 https://doi.org/10.2343/geochemj.33.317
  24. Li, X., 1993, High-P metamorphic belt in central China and its possible eastward extension to Korea. Jour. Petrol. Soc. Korea, 2, 9-18
  25. Li, Z.X., 1994, Collision between the north and south China blocks: a crustal-detachment model for suturing in the region east of the Tanlu fault. Geology, 22, 739-742 https://doi.org/10.1130/0091-7613(1994)022<0739:CBTNAS>2.3.CO;2
  26. Mukasa, S.B., Fisher, G.M. and Barr, S.M., 1996, The character of subcontinental mantle in Southeast Asia: Evidence from isotopic and elemental compositions of extension-related Cenozoic basalts, in Thailand. In: Hart, S.R. and Basu, A.R. (Eds.), Earth Processes: Reading the Isotopic Codes. AGU Geophys. Monogr., 95, 233-252
  27. Nakamura, E., Campbell, I.H., McCulloch, M.T. and Sun, S.-s., 1989, Chemical geogynamics in a back-arc region around the Sea of Japan: Implications for the genesis of alkaline basalts in Japan, Korea and China. J. Geophys. Res., 94, 4634-4654 https://doi.org/10.1029/JB094iB04p04634
  28. Nakamura, E., McCulloch, M.T. and Campbell, I.H., 1990, Chemical geodynamics in the back-arc region of Japan based on the trace element and Sr-Ndisotopic compositions. Tectonophys., 174, 207-233 https://doi.org/10.1016/0040-1951(90)90323-Z
  29. Oh, C.W., 2006, A new concept on tectonic correlation between Korea, China and Japan: histories from the late Proterozoic to Cretaceous. Gondwana Research, 9, 47-61 https://doi.org/10.1016/j.gr.2005.06.001
  30. Park, K.H., Park, J.-B., Cheong, C.-S., and Oh, C.W., 2005, Sr, Nd and Pb Isotopic Systematics of the Cenozoic Basalts of the Korean Peninsula and Their Implications for the Permo-Triassic Continental Collision Boundary. Gondwana Research, 8, 529-538 https://doi.org/10.1016/S1342-937X(05)71153-9
  31. Peng, Z.C., Zartman, R.E., Futa, K. and Chen, D.G., 1986, Pb-, Sr- and Nd-isotopic systematics and chemical characteristics of Cenozoic basalts, eastern China. Chem. Geol., 59, 3-33 https://doi.org/10.1016/0009-2541(86)90041-0
  32. Ree, J.-H., Cho, M., Kwon, S.-T., and Nakamura, E., 1996, Possible eastward extension if Chinese collision belt in south Korea: The Imjingang belt. Geology, 24, 1071-1074 https://doi.org/10.1130/0091-7613(1996)024<1071:PEEOCC>2.3.CO;2
  33. Song, Y., Frey, F.A. and Zhi, X.C., 1990, Isotopic characteristics of Hannuoba basalts, eastern China: Implications for their petrogenesis and the composition of subcontinental mantle. Chem. Geol., 85, 35-52 https://doi.org/10.1016/0009-2541(90)90122-N
  34. Tang, J., Zheng, Y.-F., Wu, Y.-B. and Gong, B., 2006, Zircon SHRIMP U-Pb dating, C and O isotopes for impure marbles from the Jiaobei terrane in the Sulu orogen: implication for tectonic affinity. Precam. Res., 144, 1-18 https://doi.org/10.1016/j.precamres.2005.10.003
  35. Tatsumoto, M., Basu, A.R., Huang, W., Wang, J. and Xie, G., 1992, Sr, Nd, and Pb isotopes of ultramafic xenoliths in volcanic rocks of eastern China: enriched components EMI and EMII in subcontinental lithosphere: Earth Planet. Sci. Lett., 113, 107-128
  36. Tatsumoto, M. and Nakamura, Y., 1991, Dupal anomaly in the Sea of Japan: Pb, Nd, and Sr isotopic variations at the eastern Eurasian continental margin. Geochim. Cosmochim. Acta, 55, 3697-3708 https://doi.org/10.1016/0016-7037(91)90068-G
  37. Tu, K., Flower, M.F.J., Carlson, R.W., Zhang, Z. and Xie, G.H., 1991, Sr, Nd, and Pb isotopic compositions of Hainan basalts (south China): implications for a sub continental lithosphere Dupal source. Geology, 19, 567-569 https://doi.org/10.1130/0091-7613(1991)019<0567:SNAPIC>2.3.CO;2
  38. Tu, K., Flower, M.F.J., Carlson, R.W., Xie, G.H., Chen, C.Y. and Zhang, M., 1992, Magmatism in the South China Basin, 1. Isotopic and trace element evidence for an endogenous Dupal mantle component. Chem. Geol., 97, 47-63 https://doi.org/10.1016/0009-2541(92)90135-R
  39. Xu, S., Okay, A.I., Ji, S., Sengor, A.M.C., Su, W., Liu, Y. and Jiang, L., 1992, Diamond from the Dabie Shan metamorphic rocks and its implication for tectonic settng. Science, 256, 80-82 https://doi.org/10.1126/science.256.5053.80
  40. Xu, X., O'Reilly, S.Y., Griffin, W.L. and Zhou, X., 2003, Enrichment of upper mantle peridotite: petrological, trace element and isotopic evidence in xenoliths from SE China. Chem. Geol., 198, 163-188 https://doi.org/10.1016/S0009-2541(03)00004-4
  41. Yin, A. and Nie, S., 1993, An indentation model for the north and south China collision and the development of the Tan-Lu and Honam fault systems, eastern Asia. Tectonics, 12, 801-813 https://doi.org/10.1029/93TC00313
  42. Zhai, M., Guo, J., Li, Z., Chen, D., Peng, P., Li, T., Hou, Q., and Fan, Q., 2007, Linking the Sulu UHP belt to the Korean peninsula: evidence from eclogite, Precambrian basement, and Paleozoic sedimentary basins. Gondwana Research, 12, 388-403 https://doi.org/10.1016/j.gr.2007.02.003
  43. Zhang, K.-J., 1997, North and South China collision along the eastern and southern North China margins. Tectonophysics, 270, 145-156 https://doi.org/10.1016/S0040-1951(96)00208-9
  44. Zhang, M., Suddaby, P., Thompson, R.N., Thirlwall, M.F. and Menzies, M.A., 1995, Potassic volcanic rocks in NE China: geochemical constraints on mantle source and magma genesis. J. Petrol., 36, 1275-1303 https://doi.org/10.1093/petrology/36.5.1275
  45. Zhou, P. and Mukasa, S.B., 1997, Nd-Sr-Pb isotopic, and majorand trace-element geodynamics of Cenozoic lavas from the Khorat Palteau, Thailand: sources and petrogenesis. Chem. Geol, 137, 175-193 https://doi.org/10.1016/S0009-2541(96)00162-3
  46. Zhou, X.H. and Armstrong, R.L., 1982, Cenozoic volcanic rocks of eastern China - secular and geographic trends in chemistry and strontium isotopic composition. Earth Planet. Sci. Lett., 59, 301-329
  47. Zindler, A. and Hart, S.R., 1986, Chemical geodynamics. Ann. Rev. Earth Planet. Sci., 14, 493-571 https://doi.org/10.1146/annurev.ea.14.050186.002425
  48. Zou, H., Zindler, A., Xu, X. and Qi, Q., 2000, Major, trace element, and Nd, Sr and Pb isotope studies of Cenozoic basalts in SE China: mantle sources, regional variations, and tectonic significance. Chem. Geol., 171, 33-47 https://doi.org/10.1016/S0009-2541(00)00243-6