Korean Journal of Mineralogy and Petrology (광물과 암석)

The Petrological Society of Korea & The Mineralogical Society of Korea (한국암석학회 & 한국광물학회)
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Change in Mineralogical Characteristics of the Laminated Diatomaceous Siliceous Mudstone by the Treatment of Consolidants

엽층리가 발달된 규조토성 규질이암의 강화제에 의한 광물학적 특성변화

  • Do, Jin Young (Department Cultural Assets, Gyeongju University)
  • 도진영 (경주대학교 문화재학과)
  • Received : 2022.03.03
  • Accepted : 2022.03.25
  • Published : 2022.03.31
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Abstract

For effective preservation of the rocks, which bearing plant fossils at Gumkwangdong Formation, Pohang, the properties of rock and treatment of chemicals were examined in an artificial weathering test. The rocks are diatomaceous siliceous mudstone, which contain a small amount of smectite and has developed laminated layers. The rocks react with water, the d001 spacing of smectite was increased. On the one hand, the physical properties of the rock samples, such as surface hardness, improved after the application of ethyl silicate-based stone strengthener. On the other hand, the spacing of interlayer of swelling clay minerals decreased and spacing of laminae layer increased. When the ethyl silicate-based stone strengthener was applied after pretreatment with a swelling inhibitor, interlayer and spacing of laminae changes were similar to those when only the stone strengthener was treated. The effect of the swelling inhibitor was almost negligible. When the rocks that have been conserved with chemicals react with water, spacing of laminae has widened much, whereas when the rocks was in contact with moisture only, there was little change. In addition, if it is placed in the outdoor after conservation treatment, although it occurs slightly slower than the untreated rock, the separation of the lamination layer and the pulverization of the rock occur within a very short time. Consolidation is required to improve the physical properties of fossil rock, but when exposed to rain and undergoing freeze-thaw process, the effect is lost very quickly. Therefore, regardless of the chemical treatment, it is a priority to prevent direct rainfall contact with the rock.

포항 금광동층 함식물화석층 암석의 효과적인 보존을 위하여 구성암석의 특징과 보존처리제 적용을 인공풍화시험을 통해 살펴보았다. 화석지 구성암석은 규조토성 규질이암으로 팽윤성 광물인 스멕타이트를 약간 함유하고 있으며, 엽층리가 발달되어 있다. 화석지 암석은 물과 반응 후 팽윤성 광물의 d001 층간간격이 증가하였다. 에틸실리케이트 암석강화제를 적용한 후 시편의 경도는 향상되었으나 팽윤성 광물의 층간간격은 감소하였다. 팽윤저지제를 선처리한 후 강화제를 처리하였을 때 광물 층간간격의 변화는 강화제만을 처리하였을 때와 유사하여 팽윤저지제의 효과는 거의 없었다. 보존약품이 처리된 암석에 수분이 닿았을 경우, 강화제 또는 팽윤저지제를 선처리한 후 강화제를 처리한 암석 모두 엽층리 간격이 확대되었으나, 습기만 접했을 때는 변화가 적었다. 또한 보존처리 후 노천에 그대로 위치하여 풍화를 받게 되면, 약품이 처리되지 않은 암석에 비해 약간 느리게 발생하기는 하지만, 매우 빠른 시간 내에 엽층리면의 분리와 암석의 분말화가 발생하는 결과를 보였다. 화석지 암석의 원활한 보존을 위해서는 보존약품의 처리가 필요하나, 강우를 접하고 동결융해과정을 거치면 그 효과는 매우 빠른 시간에 소멸되기 때문에 약품처리에 상관없이 암석에 직접적인 강우의 접촉을 막는 것이 우선적으로 요구된다.

Keywords

References

  1. Balaban, R., Vidal, E. and Borges, M., 2015, Design of experiments to evaluate clay swelling inhibition by different combinations of organic compounds and inorganic salts for application in water base drilling fluids. Applied Clay Science, 105-106, 124-130. https://doi.org/10.1016/j.clay.2014.12.029
  2. Bleam, W.F., 2012, Clay Mineralogy and Clay Chemistry. In Soil and Environmental Chemistry, Academic Press, 85-116.
  3. Do, J., 2009, Modeling Study on Deterioration of Stone Monuments in Gyeongju Namsan Mountain by Acid Rain. J. Miner. Soc. Korea, 22(1), 35-47. (in Korean with English abstract)
  4. Do, J., 2017, Deterioration of the Rock-carved Seated Buddha at Golguram Hermitage, Gyeongju and Effect of the Ethylsilicate Consolidant. J. Miner. Soc. Korea, 30(2), 71-81. (in Korean with English abstract) https://doi.org/10.9727/jmsk.2017.30.2.71
  5. Jeong, E.K., Kim, K., Kim, J.H. and Suzuki, M., 2004, Fossil woods from Janggi Group (Early Miocene) in Pohang Basin, Korea. J. Plant Research, 117, 183-189.
  6. Jiminez, G.I. and Scherer, G.W., 2004, Effect of swelling inhibitors on the swelling and stress relaxation of clay bearing stones. Environ Geol, 46, 364-377.
  7. Kim, B.G., 1970, A Study on the Neogene Tertiary Deposits in Korea. J. Geol. Soc. Korea, 6(2), 77-96. (in Korean with English abstract)
  8. Kim, K.S., 2017, The threat of damage and preservation of fossil sites : Plant Fossil sites in Gumkwangdong, Pohang. In Proc. of the 33th Annual Meeting of Paleontological Society of Korea (eds., Paleontological Society of Korea, 2017.2), 6-6.
  9. McPhee, C., Reed, J., and Zubizarreta, I., 2015, Core Analysis. In Developments in Petroleum Science (eds, McPhee, C., Reed, J., and Zubizarreta, I.), 64, 313-345. https://doi.org/10.1016/B978-0-444-63533-4.00007-X
  10. Noh, J.H., 1994, Stratigraphy, Lithology and Diagenetic Mineral Facies of the Tertiary Yeonil Group. Korean Jour. of Petrol. Geol., 2(2), 91-99. (in Korean with English abstract)
  11. Noh, J.H., 2006, Occurrence and Applied-mineralogical characterization of diatomite from the Pohang-Gampo Area. J. Miner. Soc. Korea, 19(4), 311-324. (in Korean with English abstract)
  12. Paik, I.S., Kang, H.C., Kim, H.J., Lee, H.I. Kim, K., and Jeong, E., 2010, The Geumgwangdong Formation of the Janggi Group, Pohang area: Stratigraphy, occurrences, and fossil leaf deposits. J. Geol. Soc. Korea, 46(6), 535-552. (in Korean with English abstract)
  13. Rodriguez-Navarro, C., Hansen, E., Sebastian, E., and Ginell, W. S., 2013, The Role of Clays in the Decay of Ancient Egyptian Limestone Sculptures. J. Am. Ins. Conserv., 36, 151-163. https://doi.org/10.2307/3179829
  14. Scherer, G.W. and Jimenez, G.I., 2005, Characterization of swelling in clay-bearing stone. In Stone decay and conservation (eds. Turkington AV), Geol. Soc. Am., 51-61.
  15. Wangler, T. and Scherer, G.W., 2007, Controlling swelling of Portland Brownstone, In Materials Research Society Conference Proceeding (eds. Vandiver, P., Casadio, F., McCarthy, B., Tykot, R.H., and Sil, J.), MRS, 91-104.
  16. Wangler, T., Scherer, G.W., 2009, Clay Swelling Inhibition Mechanism of α,ω-Diaminoalkanes in Portland Brownstone. JMR, 24(5), 1646-1652. https://doi.org/10.1557/jmr.2009.0190
  17. Yoon, S., 2010, Tectonic History of the Tertiary Yangnam and Pohang Basins, Korea. J. Geol. Soc. Korea, 46(2), 95-110. (in Korean with English abstract)