Browse > Article
http://dx.doi.org/10.5467/JKESS.2021.42.2.185

Concentric Structure and Radial Joint System within Basic Lava Flow at the seashore of Aewol, Jeju Island, South Korea  

Ahn, Kun Sang (Department of Earth Science, Chosun University)
Publication Information
Journal of the Korean earth science society / v.42, no.2, 2021 , pp. 185-194 More about this Journal
Abstract
A lava dome and sheet lava flow can be observed at the seashore of Aewol, Jeju island. The cylindrical lobes are characterized by a concentric structure consisting of a massive core and radial joints. Columnar joints with different thickness between the upper and lower parts are developed in the sheet lava flow around the rock salt field in Goeomri. The upper part of the columnar joints is uneven in shape, and has a diameter of 120-150 cm. The lower part of the columnar joints is hexagonal and pentagonal in shape, and has a diameter of about 60 cm. The cylindrical lobes can be divided into two groups based on size and shape. One is a megalobe, with a semicircular outline and a maximum diameter of 30 m. The other is a circular lobe with a diameter of less than 10 m. The columns in the radial joints have hexagonal and pentagonal cross sections and gradually increasing diameter, outward from the core, to a size of 80-120 cm at the rim. The concentric structure observed in the cylindrical lavas is attributable to a combination of four factors. The first is a circular crack caused by the decrease of the temperature and density difference between the inside and outside of the cylindrical lava flow. The second is a concentric chisel mark of the radial joints, which formed at the same time as the radial joints. The third is a flow band, which is a trace left in a round passage when lava flows through. The fourth is a vesicular band formed in a cave by gas bubbles escaping from the lava flow.
Keywords
concentric structure; radial joints; columnar joints; Jeju island; lava flow; lava lobe;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Ahn, K.S., 2014, Distribution and petrology of the columnar joint in South Korea. Journal of the Petrological Society of Korea, 23(2), 45-59.   DOI
2 Bermudes, A. and Delpino, D.H., 2008, Concentric and radial joint systems within basic sills and their associated porosity enhancement, Neuquen Basin. Argentina Geological Society, London, Special Publications, 302, 185-198.
3 Budkewitsch, P. and Robin, P., 1994, Modelling the evolution of columnar joints. Journal of Volcanology and Geothermal Research, 59, 219-239.   DOI
4 Goto Y. and McPhie, J., 2004, Morphology and propagation styles of Miocene submarine basanite lavas at Stanley, northwestern Tasmania, Australia. Journal of Volcanology and Geothermal Research, 130, 307-328.   DOI
5 Goto. Y. and Tsuchiya, N., 2004, Morphology and growth style of a Miocene submarine dacite lava dome at Atsumi, northeast Japan. Journal of Volcanology and Geothermal Research. 134, 255-275.   DOI
6 Hughes, S.S., Smith, R.P., Hackett, W.R. and Anderson, S.R., 1999, Mafic Volcanism and Environmental Geology of the Eastern Snake River Plain, Idaho, in Hughes, S.S., and Thackray, G.D., eds., Guidebook to the Geology of Eastern Idaho: Idaho Museum of Natural History, 143-168.
7 Park, K., Song, K., Hwang, J., Lee, B., Cho, D., Kim, J., Cho, B., Kim, Y., Choi, P., Lee, S. and Choi, H., 1998, Geologic report of the Cheju-Aewol sheet, scale1:5,0000, Cheju Provincial Goverment, 290 p.
8 Sanchez, M.C., Sarrionandia, F., Juteau, T. and Gil Ibarguchi, J.I., 2012, Structure and organization of submarine basaltic flows: sheet flow transformation into pillow lavas in shallow submarine environments. International Journal of Earth Sciences 101(8), 2201-2214.   DOI
9 Walker, G.P.L., 1992, Morphometric study of pillow-size spectrum among pillow lavas. Bulletin of Volcanology, 54, 459-474.   DOI
10 Winter, J.D., 2010, Principles of Igneous and metamorphic petrology 2nd. Prentice Hall, 54-82.
11 Yamagishi, H., Sakamoto, I. and Ishii, J., 1989, Internal structures of pillow lobes of Cenozoic and Mesozoic pillow lavas in and around Hokkaido. Proceedings of the Hokkaido Tokai University Science and Engineering, 2, 107-118.