Journal of the Korean Geographical Society (대한지리학회지)

The Korean Geographical Society (대한지리학회)
권호 표지

Geomorphic Development of Gnamma at the Summit Area of Mt. Geum, Sangju-ri, Namhae-gun, Gyeongsangnam-do

남해군 금산 정상부의 나마(Gnamma) 지형발달

  • Hwang, Sang-Ill (Department of Geography, Kyungpook National University) ;
  • Park, Hyo-Jung (Department of Geography, Kyungpook National University) ;
  • Park, Kyung-Geun (Department of Geography, Kyungpook National University) ;
  • Yoon, Soon-Ock (Department of Geography and Research Institute for Basic Sciences, Kyung Hee University)
  • 황상일 (경북대학교 지리학과) ;
  • 박효정 (경북대학교 지리학과) ;
  • 박경근 (경북대학교 지리학과) ;
  • 윤순옥 (경희대학교 지리학과 및 기초과학연구소)
  • Received : 2011.02.15
  • Accepted : 2011.04.17
  • Published : 2011.04.30
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Abstract

The types of gnamma at the summit area of Mt. Geum, Sangju-ri, Namhae-gun, Gyeongsangnam-do are classified and geomorphic developments are investigated. The rocks facing the coast show high distributional density of gnamma due to the salt supply from the coast. The water content rate of gnamma distributed in flat rocks at the summit is highest in the bottom area and lowest in the outside area. Moreover, the quartz grains are fallen due to the weathering of feldspar in the crystalline rocks such as granites and the gnamma are merged and expanded as they develop. The average weathering rate of gnamma is 0.04mm/y and it slowed with time. The results on rate indicate that the gnamma are formed and developed at the present rather than the fossil landform or by subsurface weathering.

경상남도 남해군 상주리 금산 정상부에 분포하는 나마를 대상으로 형태를 분류하고 지형발달을 조사하였다. 나마의 분포 밀도는 인접한 해안에서 공급되는 염으로 인해 해안과 변하는 암괴들에서 높았다. 또한 나마내 수분값은 나마의 형태에 따라 분포가 달라지며, 나마 바닥에서 높고 바깥쪽에서 가장 낮았다. 화강암과 같은 결정질 기반암에서 나마가 탁월하게 형성되며, 장석류의 풍화로 석영이 탈락하면서 공동이 발생한다. 나마는 성장하면서 주변 나마와 병합하여 확대된다. 나마의 형성속도는 0.04mn/y로서 초기보다 시간이 지나면서 느려졌다. 풍화속도의 계측 결과는 나마가 과거의 유물지형이나 지중풍화 기원이라기보다 현재에도 형성되고 성장, 확대되고 있음을 지시한다.

Keywords

Acknowledgement

Supported by : 기상청

References

  1. Campbell, E. M., 1997, Granite landforms, Journal of the Royal Society of Western Australia, 80(3), 101- 112.
  2. Chang, H., 1983a, Periglacial Landforms in the Eastern Part of the Main Ridge of Mt. Jiri, South Korea, Journal of the Korean Geographical Society, 27, 31-50 (in Korean).
  3. Chang, H., 1983b, The Origin and Ages of Weathering Hollows on the Rocks in Southwestern Part of Korea, Journal of Geography, 10, Seoul National University, 305-323 (in Korean).
  4. Choi, S. G., 1985, A Geomorphological Study of Shore Platform in the Protected Sea Areas -A Case Study in Jindo-island-, Journal of the Korean Geographical Society, 31, 16-31 (in Korean).
  5. Chu, M. Y., 1984, A Study on the Tafoni of Mt. Deogsung: Morphogenic Approach, Journal of Geography, 10, Seoul National University, 371- 382 (in Korean).
  6. Eswaran, H. and Bin, W. C., 1978, A study of a deep weathering profile on granite in peninsula Malaysia: III. alteration of feldspar. Soil Sci. Soc. Am. J., 42, 154-158. https://doi.org/10.2136/sssaj1978.03615995004200010034x
  7. Hwang, S. and Park, K. G., 2007, Tafoni Geomorphic Development in the Western Coast of Dongdo of Dokdo, Korea, Journal of the Korean Association of Regional Geography, 13(4), 355- 370 (in Korean).
  8. Hwang, S., Park, K. G., and Yoon, S. O, 2009, The Climactic Change and Geomorphic Development of Tafoni at the Northwestern coast of Seodo(West Island), Dokdo Island, Korea, Journal of the Korean geomorphological association, 16(1), 17-30 (in Korean).
  9. Hwang, S., Park, K. G., and Yoon, S. O., 2010, Periodic Immersion of the Bangudae Petroglyphs and Rock Weathering Characteristics, 45(3), 342-359 (in Korean).
  10. Ikeda, H., 2002, The World of Granite Landforms, Hanul, Seoul (이케다 히로시, 권동희 역, 2002, 화강암 지형의 세계, 한울아카데미, 서울).
  11. Jwa, Y. J., 1997, Petrography of the Geumsan Micrographie Granite in the Namhae Area, Journal of the Korean Earth Science Society, 18(5), 426-432 (in Korean).
  12. Kim, H. J., 1982, A Study on Tafoni in near Seoul, Master Thesis, Sangmyung University (in Korean).
  13. Kim, J. H. and Kwon, D. H., 1990, A Study on Gnammas in AAMDO, Journal of the Korean Geographical Society, 25(2), 1-11 (in Korean).
  14. Kim, J. H. and Jang J. H., 1978, A Climaticgeomorphological Study of Salt Weathering Developed in Granite Rock in Korea, Research of Geography, 4, 29-53 (in Korean).
  15. Kim, S. W., Kim, H. M., Hwang, B. H., Yang, K. Y., and Kim, J. S., 2009, Petrologic and Geomorphologic Characteristics of Micrographic Granite in the Ijin-ri Area, Ulsan, Jour. Petrol. Soc. Korea, 18(3), 211-221 (in Korean).
  16. Matsukura, Y. and Masuoka, N., 1996, The effect of rock properties on rates of tafoni growth in coastal environments, Zeit. Geomorph. Suppl., 106, 57- 72.
  17. Matsukura, Y. and Tanaka, Y., 2000, Effect of Rock Hardness and Moisture Content on Tafoni Weathering in the Granite of Mount Doeg-Sung, Korea, Geografiska Annaler. Series A, Physical Geography, 82(1), 59-67. https://doi.org/10.1111/j.0435-3676.2000.00112.x
  18. Matsuoka, N. and Norikazu, 1995, Rock weathering processes and landform development in the sor Rondane mountains, Antarctica, Geomorphology, 12, 323-339. https://doi.org/10.1016/0169-555X(95)00013-U
  19. Nesbitt, H. W. and Yong, G. M., 1982, Early Proterozoic climates and plate motions inferred form major element chemistry of lutites, Nature, 299, 715- 717. https://doi.org/10.1038/299715a0
  20. Park, H. D., 2004, An Analysis of Weathering Hollows on the Rocks around Mt. Songnisan, Journal of the Korean geomorphological association, 11(4), 35-45 (in Korean).
  21. Park, H. J., 2008, Gnamma geomorphology at the peak of Gumsan mountain in Sangju-ri, Namhae-gun, Master Thesis, Kyungpook National University, Korea (in Korean).
  22. Park, K., 2009, A Study on Tafoni Landforms in West Coast and Islands of Korea, Journal of the Korean Geomorphological Association, 16(4), 73-84 (in Korean).
  23. Rogner, K., 1988, Measurements of cavernous weathering at Machtesh Hagadol(Negev, Israel): a semiquantitative study, Catena, Suppl., 12, 67-76.
  24. Twidale, C. R., 1982, Granite landform, Elsevier, amsterdam.
  25. Twidale, C. R. and Vidal Romani, J. R., 2005, Landforms and Geology of Granite terrains, Balkema.