Economic and Environmental Geology (자원환경지질)

The Korean Society of Economic and Environmental Geology (대한자원환경지질학회)
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Interpretation of Physical Weathering and Deterioration Mechanism for Thermal Altered Pelitic Rocks: Ulju Cheonjeon-ri Petroglyph

열변질 이질암의 물리적 풍화작용과 손상메커니즘 해석: 울주 천전리 각석

  • Chan Hee Lee (Department of Cultural Heritage Conservation Sciences, Kongju National University) ;
  • Yu Gun Chun (Department of International Cooperation, Korea Cultural Heritage Foundation)
  • 이찬희 (국립공주대학교 문화재보존과학과) ;
  • 전유근 (한국문화재재단 국제협력단)
  • Received : 2023.09.01
  • Accepted : 2023.12.11
  • Published : 2023.12.29
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Abstract

Host rock of Cheonjeon-ri petroglyph is shale belonging to the Daegu Formation of Cretaceous Gyeongsang Supergroup. The rocks were hornfelsified by thermal alteration, and shows high density and hardness. The petroglyph forms weathered zone with certain depth, and has difference in mineral and chemical composition from the unweathered zone. As the physical deterioration evaluations, most of cracks on the surface appear parallel to the bedding, and are concentrated in the upper part with relatively low density. Breakout parts are occurred in the upper and lower parts of the petroglyph, accounting for 6.0% of the total area and occurs to have been created by the wedging action of cracks crossing. The first exfoliation parts occupying the surface were 23.8% of the total area, the second exfoliations covered with 9.3%, and the exfoliation parts with three or more times were calculated as 3.4%. It is interpreted that this is not due to natural weathering, and the thermal shock caused by the cremation custom here in the past. As the ultrasonic properties, the petroglyph indicates highly strength in the horizontal direction parallel to bedding, and the area with little physical damage recorded mean of 4,684 m/s, but the area with severe cracks and exfoliations showed difference from 2,597 to 3,382 m/s on average. Physical deterioration to the Cheonjeon-ri petroglyph occurred to influence by repeated weathering, which caused the rock surface to become more severe than the inside and the binding force of minerals to weaken. Therefore, it can be understood that when greater stress occurs in the weathered zone than in the unweathered zone, the relatively weathered surface loses its support and exfoliation occurs.

천전리 각석의 모암은 백악기 경상누층군의 대구층에 속하는 셰일이다. 이 암석은 열변질을 받아 혼펠스화 되어 경도가 높고 치밀한 조직을 갖는다. 각석의 표면은 일정한 깊이의 풍화대를 형성하고 있으며 비풍화대와는 광물 및 화학조성에 차이가 있다. 각석의 물리적 손상도 평가 결과, 균열은 대부분 층리와 평행하게 나타나며 상대적으로 조직의 치밀도가 낮은 상부에 집중된다. 탈락은 각석의 상부와 하부에서 전체 면적의 6.0%를 차지하며, 균열이 교차하는 쐐기작용에 따라 생성된 것으로 보이다. 표면을 점유하는 1차 박락은 전체면적의 23.8%이며, 2차 박락은 9.3%, 3차례 이상 발생한 박락은 3.4%로 산출되었다. 이는 자연적 풍화와 과거 이곳에서 화장하던 풍습으로 인한 열충격이 영향을 주었을 것으로 판단된다. 초음파 물성으로 보아 각석은 층리와 평행한 수평방향으로 높은 강도를 지시하며, 물리적 손상이 적은 영역은 평균 4,684m/s를 기록하였으나 균열대 및 박리박락이 심한 곳은 평균 2,597에서 3,382m/s로 차이를 보였다. 천전리 각석의 물리적 손상은 풍화작용이 반복되면서 암석 표면이 내부보다 정도가 심화되고 광물의 결합력이 약해져 나타난 것으로 보인다. 따라서 비풍화대보다 풍화대에서 응력이 크게 발생할 때 상대적으로 풍화된 표면이 지지력을 잃고 박락이 발생한 것으로 이해할 수 있다.

Keywords

References

  1. Chaki, S., Takarli, M. and Agbodjan, W.P. (2008) Influence of thermal damage on physical properties of a granite rock: Porosity, permeability and ultrasonic wave evolutions. Construction and Building Materials, v.22, p.1456-1461. doi: 10.1016/j.conbuildmat.2007.04.002 
  2. Benavente, D., Garcia del Cura, M.A., Garcia-Guinea, J., Sanchez-Moral, S. and Ordonez, S. (2004) Role of pore structure in salt crystallisation in unsaturated porous stone. Journal of Crystal Growth, v.260, p.532-544. doi: 10.1016/j.jcrysgro.2003.09.004 
  3. Choi, B.R. (2002) Study of rock slope stability in Bangudae area. Bulletin of Science Education of Chungbuk National University, v.18, p.57-62. (in Korean with English 
  4. Chun, Y.G., Lee, C.H., Jo, S.N., Jo, Y.H., Park, G.J. and Yang, P.S. (2008) Measurement of crack depth and weathering degree using ultrasonic velocity and deterioration evaluation of the Unhyungung stone water container. Journal of Conservation Science, v.24(1), p.1-11. (in Korean with English 
  5. Davidge, R.W. (1981) Cracking at grain boundaries in polycrystalline brittle materials. Acta Metal, v.29, p.1696-1702. doi: 10.1016/0001-6160(81)90004-3 
  6. Davison, G.P. and Nye, J.F. (1985) A photoelastic study of ice pressure in rock cracks. Cold Regions Science and Technology, v.11, p.141-153. doi: 10.1016/0165-232X(85)90013-8 
  7. Everett, D.H. (1961) The thermodynamics of frost damage to porous solids. Transactions of the Faraday Society, v.57, p.1541-1551. doi: 10.1039/TF9615701541 
  8. Fitzner, B., Heinrichs, K. and Bouchardiere, D.L. (2004) The Bangudae petroglyph in Ulsan, Korea: Studies on weathering damage and risk prognosis. Environmental Geology. v.46, p.504-526. doi: 10.1007/s00254-004-1052-x 
  9. Heuze, F.E. (1983) High-temperature mechanical, physical and thermal properties of granitic rocks: a review. International Journal of Rock Mechanics and Mining Science Geomechanical Abstract, v.20, p.3-10. doi: 10.1016/0148-9062(83)91609-1 
  10. Hobbs, P.V. (1974) Ice Physics. Clarendon Press, p.1-837.
  11. Hwang, S., Park, K. and Yoon, S.O. (2010) Periodic immersion of the Bangudae petroglyphs and rock weathering characteristics. Journal of the Korean Geographical Society, v.45(3), p.342-359. (in Korean with English 
  12. Hwang, S.Y. and Moon, M.D. (1984) Bangudae. Dongguk University, p.1-243. (in Korean) 
  13. Jeon, H.T. (2000) Conservation Theory of Ulsan Bangudae Petroglyph. The Journal of Korean Petroglyph, v.2, p.47-67. (in Korean with English 
  14. Jo, Y.H. and Lee, C.H. (2011) Making method of deterioration map and evaluation techniques of surface and three-dimensional deterioration rate for stone cultural heritage. Journal of Conservation Science, v.27(3), p.251-260. (in Korean with English 
  15. Jo, Y.H. and Lee, C.H. (2012) Three-dimensional digital restoration and surface depth modeling for shape analysis of stone cultural heritage: Haeundae Stone Inscription. Journal of Conservation Science, v.28(1), p.87-94. (in Korean with English  https://doi.org/10.12654/JCS.2012.28.1.087
  16. Jo, Y.H. and Lee, C.H. (2014a) Quantitative modeling of blistering zones by active thermography for deterioration evaluation of stone monuments. Journal of Cultural Heritage, v.15, p.621-627. doi: 10.1016/j.culher.2013.12.002 
  17. Jo, Y.H. and Lee, C.H. (2014b) Establishment of ultrasonic measurement method for stone cultural heritage considering water content and anisotropy. Journal of Conservation Science, v.30(4), p.467-480. (in Korean with English abstract) doi: 10.12654/JCS.2014.30.4.15 
  18. Jo, Y.H. and Lee, C.H. (2015) A study on selection of ultrasonic transducer and contact material for surface irregularities of stone cultural heritage. Journal of Conservation Science, v.31(3), p.267-278. (in Korean with English abstract) doi: 10.12654/JCS.2015.31.3.07 
  19. Jo, Y.H., Lee, C.H. and Yoo, J.H. (2013) Study on applicability of passive infrared thermography analysis for blistering detection of stone cultural heritage. Journal of Conservation Science, v.29(1), p.55-67. (in Korean with English abstract) doi: 10.12654/JCS.2013.29.1.06 
  20. Johnson, B., Gangi, A. and Handin, J. (1978) Thermal cracking of rock subjected to slow uniform temperature changes. The 19th US Symposium on Rock Mechanics, p.259-267. 
  21. Kiessl, K. (1989) Bauphysikalische Einflusse bei der Krustenbildung am Gestein alter Bauwerke. Bauphysik, v.11, H.1,S, p.44-49. 
  22. Kingery, W.D., Bowen, H.K. and Uhlmann, D.R. (1976) Introduction to Ceramics. John Wiley and Sons, p.1-1032. 
  23. Lee, C.H. (2020) Interpretation of deterioration mechanism and scientific diagnosis for Cheonjeon-ri Petroglyphs. Korean Rock Art IV. Ulsan Cheonjeon-ri petroglyphs. Ulsan Petroglyph Museum, p.310-369. (in Korean) 
  24. Lee, C.H. and Araki, N. (2019) Evaluation of nondestructive diagnosis and material characteristics of stone lantern at Damyang Gaeseonsaji temple site in Korea. Journal of Conservation Science, v.35(4), p.279-293. doi: 10.12654/JCS.2019.35.4.02 
  25. Lee, C.H. and Chun, Y.G. (2022) Modeling of geochemical variations and weathering depth on the surface of pelitic rocks in periodical submerging zone: Bangudae petroglyphs. Economic and Environmental Geology, v.55(6), p.583-596. (in Korean with English abstract) doi: 10.9719/EEG.2022.55.6.583 
  26. Lee, C.H. and Chun, Y.G. (2023) Evaluation and weathering depth modeling of thermally altered pelitic rocks based on chemical weathering and variations: Ulju Cheonjeon-ri petroglyphs. Korean Journal of Cultural Heritage Studies, v.56(4), 160-189. (in Korean with English  https://doi.org/10.9719/EEG.2023.56.6.629
  27. Lee, C.H., Chun, Y.G., Jo, Y.H. and Suh, M. (2012) Evaluation of slope stability and deterioration degree for Bangudae petroglyphs in Ulsan, Korea. Journal of Conservation Science, v.28(2), p.153-164. (in Korean with English abstract) doi: 10.12654/JCS.2012.28.2.153 
  28. Lee, C.H., Kim, M.Y., Lee, M.S. and Jo, Y.H. (2010) Conservation treatment based on material characteristics, provenance presumption and deterioration diagnosis of the Seven-storied Jungwon Tappyeongri stone pagoda, Chungju, Korea. Korean Journal of Cultural Heritage Studies, v.43(3), p.4-25. (in Korean with English abstract) 
  29. Lee, C.H. and Jo, Y.H. (2017) Correlation and correction factor between direct and indirect methods for the ultrasonic measurement of stone samples. Environmental Earth Science, v.76, p.477-489. doi: 10.1007/s12665-017-6810-7 
  30. Lee, C.H., Jo, Y.H. and Chun, Y.G. (2009) Establishment of ultrasonic measurement and correlations of direct-indirect method for weathering evaluation of stone cultural heritage. Journal of Conservation Science, v.25(3), p.233-244. (in Korean with English abstract) 
  31. Lee, C.H., Lee, M.S. and Suh, M. (2005) Safety interpretations of the discontinuity and weathering characteristics of the Gaheungri triple Buddha statue, Yeongju, Korea. Journal of Geological Society of Korea, v.41(3), p.401-413. (in Korean with English abstract) 
  32. Lee, H.W. and Lee, J.I. (1995) A study on thermal shock, thermal expansion and thermal cracking of rocks under high temperature. Tunnel and Underground Space, v.5(1), p.22-40. (in Korean with English 
  33. Lee, K.H., Lee, H.W. and Shin, J.S. (1990) A study on thermal cracking and physical properties of two granitic stones. Geosystem Engineering, v.27, p.31-42. (in Korean with English 
  34. Lee, S.H. and Kim, S.J. (2004) Weathering characteristics of sedimentary rocks affected by periodical submerging. Journal of Mineralogical Society of Korea, v.17(1), p.23-35. (in Korean with English 
  35. Lee, Y.J. and Lee, I.G. (1972) Geological Map and Explanation: Eonyang Sheet (1:50,000). Geological Survey of Korea, p.1-15. (in Korean with English 
  36. Moon, M.D. (1973) Prehistoric Petroglyphs in Ulsan. Korean Journal of Cultural Heritage Studies, v.7, p.1-11. (in Korean) 
  37. Park, S.S., Ye, S.R. and Kim, G.W. (2016) Slaking characteristics of shale in the Gyoungsang Supergroup, Korea. Journal of Engineering Geology, v.26(3), p.315-324. (in Korean with English abstract) doi: 10.9720/kseg.2016.3.315 
  38. Schulson, E.M. (1998) Ice Damage to Concrete. CRREL, Special Report, p.98-106. 
  39. Simmons, G. and Cooper, H.W. (1978) Thermal cycling crack in three igneous rock. International Journal of Rock Mechanics and Mining Science Geomechanical Abstract, v.15, p.145-148. doi: 10.1016/0148-9062(78)91220-2 
  40. Tharp, T.M. (1987) Conditions for crack propagation by frost wedging. Geological Society of America Bulletin, v.99, p.94-102. doi: 10.1130/0016-7606(1987)99%3C94:CFCPBF%3E2.0.CO;2 
  41. Ulsan Metropolitan City (2003) Survey Report of National Treasure No. 147 Cheonjeon-ri Gakseok. Institute of Korea Prehistoric Art, p.1-134. (in Korean) 
  42. Yim, S.K. (1999) Petroglyphs in Korea. Daewonsa, p.1-143. (in Korean)