자원환경지질 (Economic and Environmental Geology)

  • 제53권5호
  • /
  • Pages.553-564
  • /
  • 2020
  • /
  • 1225-7281(pISSN)
  • /
  • 2288-7962(eISSN)
대한자원환경지질학회 (The Korean Society of Economic and Environmental Geology)
권호 표지
DOI QR코드

DOI QR Code

울릉도 알봉 용암돔의 미정 조직분석으로부터 폭발성 및 분류성 분출 간의 전환 해석

Interpretion of Transition between Explosive and Effusive Eruptions from Microlite Textural Analyses in the Albong Lava Dome, Ulleung Island, Korea

  • 황상구 (안동대학교 자연과학대학 지구환경과학과) ;
  • 김기범 (안동대학교 자연과학대학 지구환경과학과) ;
  • 손영우 (한국수자원공사) ;
  • 현혜원 (안동대학교 자연과학대학 지구환경과학과)
  • Hwang, Sang Koo (Department of Earth and Environmental Sciences, Andong National University) ;
  • Kim, Ki Beom (Department of Earth and Environmental Sciences, Andong National University) ;
  • Son, Young Woo (Korea Water Resources Corporation) ;
  • Hyeon, Hye Weon (Department of Earth and Environmental Sciences, Andong National University)
  • 투고 : 2020.07.31
  • 심사 : 2020.10.13
  • 발행 : 2020.10.28
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

울릉도에서 폭발성 및 분류성 분출 간의 전환은 돔형성 분출을 나타내는 나리분석층과 알봉조면안산암(용암돔)에서 관찰되며, 유동성 마그마, 상승률 및 탈기작용과 같은 요인과 연관된다. 그러나 이들에 대한 해석은 요인들 간의 상호작용이 복잡할 뿐만 아니라 분출과정에서의 거동을 예측하기 어렵기 때문에 지금까지 해결되지 않았다. 이 논문은 나리 칼데라에서 알봉 용암돔 형성과정에서 인지되는 폭발성 및 분류성 분출에 초점을 두었다. 시료는 분석층과 용암돔에서 시간에 따라 채취하였으며, 분출 단계 및 활동 양식과 연계되어 있다. 이 시료들에서 석기 장석미정의 조직은 면적 개수밀도, 평균 미정크기, 결정 종횡비, 석기 결정률 등을 포함하며 정량적으로 분석되었다. 이러한 미정의 조직은 천부에서 분출전 및 분출동시 마그마 과정이 분출 동안 거동변화를 제어하면서 진행되었다는 것을 보여준다. 폭발성 및 분류성 분출 간의 전환은 주로 화도 내 마그마 상승의 역학관계에 의해 일어났으며, 탈기작용과 결정작용이 피드백 메카니즘을 통해 일어남으로서 분류성 및 폭발성 분출의 한 윤회를 초래했다.

Transition between explosive and effusive eruption in Ulleung Island is observed in the Nari Scoria Deposits and Albong Trachyandesite (lava dome) origined by dome-building eruption and may be related to factors such as magma influx, ascent rate and degassing. However, the interpretation of them has not been resolved yet because the interaction between these factors is not complex but also the resulting behaviour during eruption is unpredictable. This paper focuses on the explosive and effusive activity perceived during building the Albong lava dome in Nari caldera. Samples were collected along with time from the scoria deposits and lava dome, linked to eruption stage and style of activity. Textures of groundmass feldspar microlites from these samples are quantitatively analyzed, including measurements of areal number density, mean microlite size, crystal aspect ratio, groundmass crystallinity and crystal size. The microlite textures show that shallow pre- and syn-eruptive magmatic processes acted to govern the changing behaviour during the eruption. Transition between explosive and effusive eruption was driven by the dynamics of magma ascent in the conduit, with degassing and crystallisation acting via feedback mechanisms, resulting in a cycle of effusive and explosive eruption.

키워드

참고문헌

  1. Cashman, K.V. (1988) Crystallization of Mount St. Helens 1980-1986 dacite: a quantitative textural approach. Bull. Volcanol., v.50, p.194-209. https://doi.org/10.1007/BF01079682
  2. Cashman, K.V. (1992) Groundmass crystallization of Mount St Helens dacite, 1980-1986 - a tool for interpreting shallow magmatic processes. Contrib. Mineral. Petrol., v.109, p.431-449. https://doi.org/10.1007/BF00306547
  3. Cashman, K.V. and McConnell, S.M. (2005) Multiple levels of magma storage during the 1980 summer eruptions of Mount St. Helens, WA. Bull. Volcanol., v.68, p.57-75. https://doi.org/10.1007/s00445-005-0422-x
  4. Clarke, A.B., Stephens, S., Teasdale, R., Sparks, R.S.J. and Diller, K. (2007) Petrologic constraints on the decompression history of magma prior to Vulcanian explosions at the SoufrièreHills Volcano, Monterrat. J. Volcanol. Geotherm. Res., v.161, p.261-274. https://doi.org/10.1016/j.jvolgeores.2006.11.007
  5. Couch, S., Sparks, R.S.J. and Carroll, M.R. (2003) The kinetics of degassing-induced crystallization at Soufrière Hills volcano, Montserrat. J. Petrol., v.44, p.1477-1502. https://doi.org/10.1093/petrology/44.8.1477
  6. Geschwind, C.-H. and Rutherford, M.J. (1995) Crystallization of microlites during magma ascent: the fluid mechanics of 1980-1986 eruptions at Mount St. Helens. Bull. Volcanol., v.57, p.356-370. https://doi.org/10.1007/BF00301293
  7. Hammer, J.E., Cashman, K.V., Hoblitt, R.P. and Newman, S. (1999) Degassing and microlite crystallization during pre-climactic events of the 1991 eruption of Mt. Pinatubo, Philippines. Bull. Volcanol., v.60, p.355-380. https://doi.org/10.1007/s004450050238
  8. Hess, K.-U. and Dingwell, D.B. (1996) Viscosities of hydrous leucogranite melts: a non-Arrhenian model. Am. Mineralog., v.81, p.1297-1300.
  9. Hoblitt, R.P. and Harmon, R.S. (1993) Bimodal density distribution of cryptodome dacite from the 1980 eruption of Mount St. Helens, Washington. Bull. Volcanol., v.55, p.421-437. https://doi.org/10.1007/BF00302002
  10. Hwang, S.K., Hwang, J.H. and Kwon, C.W. (2012) Geological report of the Ulleungdo Sheet. KIGAM, 83p.
  11. Hwang, S.K. and Jo I.H. (2014) Petrologic Evolution Processes of the Latest Volcanic Rocks in Ulleung Island, East Sea. J. Geol. Soc. Korea, v.50, p.343-363. https://doi.org/10.14770/jgsk.2014.50.3.343
  12. Hwang, S.K., Lee, S.-J. and Oh, K.S. (2020) The Latest Volcanism in Nari Caldera, Ulleung Island: Transition from Explosive to Effusive Eruption. J. Geol. Soc. Korea, v.56, p.539-553. https://doi.org/10.14770/jgsk.2020.56.5.539
  13. Kim, G.B., Cronin, S.J., Yoon, W.S. and Sohn, Y.K. (2014) Post 19 ka B.P. eruptive history of Ulleung Island, Korea, inferred from an intra-caldera pyroclastic sequence. Bull. Volcanol., v.76, no.802, DOI 10.1007/s00445-014-0802-1.
  14. Melnik, O. and Sparks, R.S.J. (1999) Nonlinear dynamics of lava dome extrusion. Nature, v.402, p.37-41. https://doi.org/10.1038/46950
  15. Melnik, O. and Sparks, R.S.J. (2005) Controls on conduit magma flow dynamics during lava dome building eruptions. J. Geophys. Res., v.110, B02209.
  16. Melnik, O.E., Blundy, J.D., Rust, A.C. and Muir, D.D. (2011) Subvolcanic plumbing systems imaged through crystal size distributions. Geology, v.39, p.403-406. https://doi.org/10.1130/G31691.1
  17. Murphy, M.D., Sparks, R.S.J., Barclay, J., Carroll, M.R. and Brewer, T.S. (2000) Remobilization of andesite magma by intrusion of mafic magma at the Soufriere Hills volcano, Montserrat, West Indies. J. Petrol., v.41, p.21-42. https://doi.org/10.1093/petrology/41.1.21
  18. Newhall, C.G. and Melson, W.G. (1983) Explosive activity associated with the growth of volcanic domes. J. Volcanol. Geotherm. Res., v.17, p.111-131. https://doi.org/10.1016/0377-0273(83)90064-1
  19. Ogburn, S.E., Loughlin, S.C. and Calder, E.S. (2015) The association of lava dome growth with major explosive activity (VEI${\geq}$4): DomeHaz, a global dataset. Bull. Volcanol., v.77, no.40. DOI: 1007/s0045-015-0919-x.
  20. Pallister, J.S., Thornber, C.R., Cashman, K.V., Clynne, M.A., Lowers, H.A., Mandeville, C.W., Brownfield, I.K. and Meeker, G.P. (2008) Petrology of the 2004-2006 Mount St. Helens lava dome-implications for magmatic plumbing and eruption triggering. US Geol. Surv. Prof. Pap., v.1750, p.647-702.
  21. Ridolfi, F., Puerini, M., Renzulli, A., Menna, M. and Toulkeridis, T. (2008) The magmatic feeding system of El Reventador volcano (Sub-Andean zone, Ecuador) constrained by texture, mineralogy and thermobarometry of the 2002 erupted products. J. Volcanol. Geotherm. Res., v.176, p.94-106. https://doi.org/10.1016/j.jvolgeores.2008.03.003
  22. Sparks, R.S.J. (1997) Causes and consequences of pressurisation in lava dome eruptions. Earth Planet. Sci. Lett., v.150, p.177-189. https://doi.org/10.1016/S0012-821X(97)00109-X
  23. Swanson, S.E., Naney, M.T., Westrich, H.R. and Eichelberger, J.C. (1989) Crystallization history of Obsidian Dome, Inyo Domes, California. Bull. Volcanol., v.51, p.161-176. https://doi.org/10.1007/BF01067953
  24. Wolf, K.J. and Eichelberger, J.C. (1997) Syneruptive mixing, degassing, and crystallization at Redoubt Volcano, eruption of December 1989 to May 1990. J. Volcanol. Geotherm. Res., v.75, p.19-37. https://doi.org/10.1016/S0377-0273(96)00055-8
  25. Wright, H.M.N., Cashman, K.V., Rosi, M. and Cioni, R. (2007) Breadcrust bombs as indicators of Vulcanian eruption dynamics at Guagua Pichincha volcano, Ecuador. Bull. Volcanol., v.69, p.281-300. https://doi.org/10.1007/s00445-006-0073-6