Economic and Environmental Geology (자원환경지질)

The Korean Society of Economic and Environmental Geology (대한자원환경지질학회)
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Reassessment of the Pyeongan Supergroup: Metamorphism and Deformation of the Songrim Orogeny

평안누층군의 재조명: 송림 조산운동의 변성작용과 변형작용

  • Kim, Hyeong Soo (Department of Earth and Environmental Sciences, Korea University)
  • 김형수 (고려대학교 지구환경과학과)
  • Received : 2019.08.08
  • Accepted : 2019.10.04
  • Published : 2019.10.28
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Abstract

Pyeongan Supergroup (PS) in the Taebaeksan basin preserves key geological evidences to understand the tectonometamorphic evolution of the Songrim orogeny that affected the formation of the Korean Peninsula during the late Paleozoic to early Mesozoic. The aims of this paper therefore are to investigate the characteristics of the Songrim orogeny based on the previous results of metamorphism and deformations of the PS, and then to review geological significance and research necessity of the PS. Age distributions and Th/U ratio of detrital zircon in the PS indicate that sedimentary environment of the Taebaeksan basin during the late Paleozoic was arc-related foreland basin and retro-arc foreland basin at the active continental margin. In addition, the main magmatic activities occurred in the early Pennsylvanian and Middle Permian, thus sedimentation and magmatic activities occurred simultaneously. The PS was affected by lower temperature-medium pressure (M1) and medium temperature and pressure (M2) regional metamorphism during the Songrim orogeny. During M1, slate and phyllite containing chloritoid, andalusite, kyanite porphyroblasts intensively deformed by E-W bulk crustal shortening combined with folding and shearing. And garnet and staurolite porphyroblasts were formed during the N-S bulk crustal shortening accompained by M2. Such regional metamorphism of the PS is interpreted to occur in an area where high strain zone is localized during ca. 220-270 Ma. In order to elucidate the evolution of the Taebaeksan basin and tectonic features of the Songrim orogeny, it is expected that the study will be carried out such as the regional distribution of metamorphic zones developed in the PS, characteristics and timing of deformations, and late Paleozoic paleo-geography of the Taebaeksan basin.

태백산분지에 분포하는 평안누층군은 고생대 말-중생대 초기 동안 한반도 형성에 영향을 미친 송림 조산운동의 지구조적 특성을 이해하는데 필요한 지질학적 증거들을 가지고 있다. 따라서 이번 논문은 기존에 발표된 평안누층군의 변성-변형작용과 쇄설성 저어콘의 연령측정 결과들을 바탕으로 송림 조산운동의 특성을 알아보고, 평안누층군의 지질학적 중요성과 연구 필요성에 대해 고찰해 보고자 한다. 평안누층군의 쇄설성 저어콘의 Th/U 비와 연령분포 결과는 고생대 말 태백산분지의 퇴적환경은 능동적 대륙연변부의 화산호 형성으로 인해 만들어진 대륙전호분지와 후호 대륙전면분지일 것으로 판단된다. 또한 주된 화성활동은 펜실베니안 초기와 페름기 중기에 발생하였고, 따라서 평안누층군의 퇴적작용과 화성활동은 거의 동시기에 발생하였다. 송림 조산운동 동안 평안누층군은 저온-중압(M1)과 중온-중압(M2)의 광역변성작용에 영향을 받았다. M1 동안 경녹니석, 홍주석, 남정석 반성변정을 함유한 점판암과 천매암은 동-서 방향의 압축작용과 함께 수반된 습곡/전단운동에 의해 심하게 변형되어 산출되며, M2와 함께 수반된 남-북 방향의 최대 압축작용 동안 석류석과 십자석이 반상변정으로 형성되었다. 이런 평안누층군의 변성작용은 약 220-270 Ma 동안에 변형작용이 집중되는 지역에서 발생한 것으로 해석된다. 향후 고생대 태백산분지의 진화와 송림 조산운동의 지구조적 특성을 규명하기 위해서 평안누층군에 발달한 변성대의 광역적인 분포와 지질구조들의 특성과 형성 시기 그리고 고생대 말 태백산분지의 고지리 위치 등과 같은 연구가 수행되기를 기대한다.

Keywords

References

  1. Cheong, C.H. (1969) Stratigraphy and paleontology of the Samcheog coalfield, Gangweondo, Korea (1). J. Geol. Soc. Korea, v.5, p.13-56.
  2. Cho, D-L, Lee, S.R., and Armstrong, R. (2008) Termination of the Permo-Triassic Songrim (Indosinian) orogeny in the Ogcheon belt, South Korea: Occurrence of ca. 220 Ma post-orogenic alkali granites and their tectonic implications. Lithos, v.105, p.191-200. https://doi.org/10.1016/j.lithos.2008.03.007
  3. Choi, D.K. (2014) Geology and Tectonic evolution of the Korean Peninsula. Seoul National University Press, 277p.
  4. Choi, P.Y., Lim, S.B., Kim, B.C. and Kwon, S.K. (1998) Middle Triassic to Middle Jurassic deformations in the SW Mungyeong coal field, Korea. In: Koh, H.J., Lee, B.J. (Eds), Tectonic evolution of East Asia: The 1st Joint Meeting of Japanese and Korean Structural and Tectonic Research Group, p.68-73.
  5. Chough, S.K., Kwon, S.-T., Ree, J.-H. and Choi, D.K. (2000) Tectonic and sedimentary evolution of the Korean peninsula: a review and new view. Earth-Sci. Rev., v.52, p.175-235. https://doi.org/10.1016/S0012-8252(00)00029-5
  6. de Jong, K., Kurimoto, C. and Ruffet, G. (2009) Triassic $^{40}Ar/^{39}Ar$ ages from the Sakaigawa unit, Kii Peninsula, Japan: implication for possible merger of the Central Asian Orogenic Belt with large-scale tectonic systems of the East Asia margin, Inter. J. Earth Sci.(Geol. Rundsch), v.98, p.1529-1556. https://doi.org/10.1007/s00531-008-0340-1
  7. Geological Investigation Corps of the Taebaeksan Region(GICTR), 1962. Geologic Atlas of Taebaeksan Region. Geol. Soc. Korea(K-E).
  8. Han, R., Min, K., Ree, J.-H. and Foster, D. A. (2013) Extensional deformation along the southern boundary of the Gyeonggi Massif, South Korea: structural characteristics, age constraints, and tectonic implications. Inter. J. Earth Sci.(Geol. Rundsch), v.103, 757-776. https://doi.org/10.1007/s00531-013-0985-2
  9. Han, R., Ree, J-H., Cho, D-L., Kwon, S-T. and Armstrong R. (2006) SHRIMP U-Pb zircon ages of pyroclastic rocks in the Bansong Group, Taebaeksan Basin, South Korea and their implication for the Mesozoic tectonics. Gondwana Res., v.9, p.106-117. https://doi.org/10.1016/j.gr.2005.06.006
  10. Hornik, K. (2015) Frequently asked questions on R. https://CRAN.R-project.org/doc/FAQ/RFAQ.html.
  11. Hwang, S.G. (1998) Thrust and intrusion tectonics in the Jeomchon area. In: Kho, H.J., Lee, B.J., Eds, Tectonic evolution of East Asia. The 1st Joint meeting of Japanese and Korean Structure and Tectonic Research Group, p.60-67.
  12. Kawasaki, S. (1927) The Flora of the Heian (Pyongan) System. Part 1, Bull. Geol. Surv., Chosen(Korea), 6, 1, 20p.
  13. Kihm, Y.H., Hwang, J.H. and Kim, S.W. (2012) Geological structures of the northern Gangneung coalfield. J. Geol. Soc. Korea, v.48, p.131-147.
  14. Kim, D.-Y., Choi, S.-J. and Yi, K. (2015) SHRIMP U-Pb Zircon Ages of the Metapsammite in the Yeongam-Gangjin Area. Eco. Environ. Geol. v.48, p.287-299. https://doi.org/10.9719/EEG.2015.48.4.287
  15. Kim, H.S. (2012) P-T modeling of margarite+anorthite-bearing Al-rich metapelites in the Taebaeksan basin, South Korea: implications for accretion-related metamorphism during the Late Permian-Triassic orogeny. Geosci. J., v.16, p.207-227. https://doi.org/10.1007/s12303-012-0024-5
  16. Kim, H.S. and Ree, J.-H. (2010) P-T modeling of kyanite and sillimanite paramorphs growth after andalusite in late Paleozoic Pyeongan Supergroup, South Korea: implication for metamorphism during the Mesozoic tectonic evolution. Lithos, v.118, p.269-286. https://doi.org/10.1016/j.lithos.2010.05.005
  17. Kim, H.S. and Ree, J.-H. (2013) Permo-Triassic changes in bulk crustal shortening direction during deformation and metamorphism of the Taebaeksan Basin, South Korea using foliation intersection/inflection axes: implications for tectonic movement at the eastern margin of Eurasia during the Songrim (Indosinian) orogeny. Tectonophysics, v.587, p.133-154. https://doi.org/10.1016/j.tecto.2012.08.033
  18. Kim, H.S. and Yi, K. (2015) Multiple metamorphic episodes recorded in the Paleozoic Pyeongan Supergroup on the northeastern margin of the Yeongnam massif, South Korea: Implications for the Songrim (Indosinian) orogeny. J. Asian Earth Sci., v.113, p.883-896. https://doi.org/10.1016/j.jseaes.2015.09.012
  19. Kim, H.S., Choh, S.-J., Lee, J.-H. and Kim, S.J. (2019) Sediment grain size does matter: implications of spatiotemporal variations in detrital zircon provenance for early Paleozoic peri-Gondwana reconstructions. Inter. J. Earth Sci.(Geol. Rundsch), v.108, p.1509-1526. https://doi.org/10.1007/s00531-019-01717-7
  20. Kim, H.S., Hwang, M.-K., Ree, J.-H. and Yi, K. (2013) Tectonic linkage between the Korean Peninsula and mainland Asia in the Cambrian: insights from U-Pb dating of detrital zircon. Earth Planet. Sci. Lett. v.368, p.204-218. https://doi.org/10.1016/j.epsl.2013.03.003
  21. Kim, H.S., Ree, J.-H. and Yi, K. (2018) The tectonic boundary between the Okcheon and Taebaeksan basins, South Korea: A restraining bend of a continental transform fault between the South and North China Cratons. Island Arc, v.27, p.1-10.
  22. Kim, H.S., Ree, J-H. and Kim, J. (2012) Tectonometamorphic evolution of the Permo-Triassic Songrim (Indosinian) orogeny: Evidence from the late Paleozoic Pyeongan Supergroup in the northeastern Taebaeksan Basin, South Korea. Inter. J. Earth Sci., v.101, p.483-498. https://doi.org/10.1007/s00531-011-0683-x
  23. Kim, J.H., Lee, J.Y. and Nam, K.H. (1994) Pre-Jurassic thrust movement in Danyang area, Danyang coaldield, Korea. J. Geol. Soc. Korea, v.30, p.35-40.
  24. Kim, J.H., Lee, J.Y., Li, M. and Bai, Z. (2001) Comparison of the Ordovician-Carboniferous boundary between Korea and NE China: implications for correlation and tectonic evolution. Gondwana Res., v.4, p.39-53. https://doi.org/10.1016/S1342-937X(05)70653-5
  25. Kim, M.G. and Lee, Y. (2018) The Pyeongan Supergroup (upper Paleozoic-Lower Triassic) in the Okcheon Belt, Korea: A review of stratigraphy and detrital zircon provenance, and its implications for the tectonic setting of the eastern Sino-Korean Block. Earth-Sci. Rev., v.185, p.1170-1186. https://doi.org/10.1016/j.earscirev.2018.09.006
  26. Kim, S.W., Kwon, S., Santosh, M., Cho, D.L. and Ryu, I.-C. (2014) Detrital zircon U-Pb geochronology and tectonic implications of the Paleozoic sequences in western South Korea. J. Asian Earth Sci. v.95, p.217-227. https://doi.org/10.1016/j.jseaes.2014.05.022
  27. Kim, S.W., Park, S.-I., Jang, Y., Kwon, S., Kim, S.J. and Santosh, M. (2017) Tracking Paleozoic evolution of the South Korean Peninsula from detrital zircon records: Implications for the tectonic history of East Asia. Gondwana Res. v.50, p.195-215. https://doi.org/10.1016/j.gr.2017.05.009
  28. Ko, J., Yu, K-M., Rhee, B-K., Lee, J.Y. and Shin, J-B. (1999) Sandstone petrology of the Pyeongan Supergroup, Taebaeksan region, Korea; implications for the Carboniferous-Triassic tectonic history of East Asia. J. Sediment. Res., v.69, p.711-719. https://doi.org/10.2110/jsr.69.711
  29. Kodaira, R. (1924) Note on a new species of Schizoneura from Chosen(Korea). Japan J. Geol. Geogra., 3, no. 3-4(J).
  30. Korea Research Institute of Geoscience and Mineral Resources(KIGAM), (1979) Geological Altlas of the Samcheog Coalfield, 1:25,000 and Geology of the Samcheog Coafield(Expanatory text).
  31. Lee, C.-Z. (2010) The stratigraphy of the Pyeongan Supergroup of South Korea: a review. J. Korean Earth Sci. Soc. v.31, p.419-429. https://doi.org/10.5467/JKESS.2010.31.5.419
  32. Lee, H.S. and Chough, S.K. (2006a) Sequence stratigraphy of Pyeongan Supergroup (Carboniferous-Permian), Taebaek area, mideast Korea. Geosci. J., v.10, p.369-389. https://doi.org/10.1007/BF02910433
  33. Lee, H.S. and Chough, S.K. (2006b) Lithostratigraphy and depositional environments of the Pyeongan Supergroup (Carboniferous-Permain) in the Taebaek area, mid-east Korea. J. Asian Earth Sci., v.26, p.339-352. https://doi.org/10.1016/j.jseaes.2005.05.003
  34. Lee, Y.I. and Sheen, D.H. (1998) Detrital modes of the Pyeongan Supergroup (Late Carboniferous-Early Triassic) sandstones in the Samcheog coalfield, Korea: implications for provenance and tectonic setting. Sediment. Geol., v.119, p.219-238. https://doi.org/10.1016/S0037-0738(98)00053-0
  35. Sagong, H., Kwon, S.-T. and Ree, J.-H. (2005) Mesozoic episodic magmatism in South Korea and its tectonic implication, Tectonics, v.24, doi:10.1029/2004TC001720.
  36. Sanislav, I.V. and Bell, T.H. (2011) The inter-relationships between long-lived metamorphism, pluton emplacement and changes in the direction of bulk shortening during orogenesis. J. Metamorphic Geol., v.29, p.513-536. https://doi.org/10.1111/j.1525-1314.2011.00928.x
  37. Tateiwa. I. (1931) Geological atlas of Chosen (Korea), no. 12, Tonhchang, Ulsan, Pyolchangri and Songchon sheets, 1:50,000. Geol. Surv. Chosen(Korea) (J).
  38. Whiteny, D.L. and Evans, B.W. (2010). Abbreviations for names of rock-forming minerals. Am. Mineral., v.95, p.185-187. https://doi.org/10.2138/am.2010.3371
  39. Yu, K.M., Lee, G.H. and Boggs, S. (1997) Petrology of late Paleozoic early Mesozoic Pyeongan Group sandstones, Gohan area, South Korea and its provenance and tectonic implications. Sediment. Geol., v.109, p.321-338. https://doi.org/10.1016/S0037-0738(96)00069-3
  40. Zhang, S.H., Zhao, Y. and Song, B. (2006) Hornblende thermobarometry of the Carboniferous granitoids from the Inner Mongolia Paleo-uplift: implications for the tectonic evolution of the northern margin of North China block. Mineral. Petrol., v.87, p.123-141. https://doi.org/10.1007/s00710-005-0116-2