• Title/Summary/Keyword: 섭지코지

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The Basalts and Volcanic Process in the Seondol Cinder Cone, Seobjikoji Area, Jeju Island (제주도 섭지코지 선돌 분석구의 화산작용과 현무암)

  • Koh, Jeong-Seon;Yun, Sung-Hyo;Kim, Suck-Youn
    • Journal of the Korean earth science society
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    • v.28 no.4
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    • pp.462-477
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    • 2007
  • The purpose of this study is to determine the petrology of basalt and the volcanic process in the Seondol cinder cone, Seobjikoji area, eastern Jeju Island. The Seondol cinder cone is mainly composed of spatters in the lower part, pyroclastic deposits including reddish brown blocks, ashes with volcanic bombs in the middle part, and dark black scoria deposits in the upper part. The volcanic sequences suggest volcanic processes that progress through Strombolian eruption and end with Hawaiian lava effusion which breached the cinder cone northwestward and extended over northwestward as lava delta and basalt emplaced as a volcanic neck in the central part of crater in the cinder cone. The age of basalt lava flows is about $95\;{\pm}\;3\;ka$. The basalts belong to transitional basalt and show products of fractional crystallization of clinopyroxene and olivine from a parental basalt magma on the basis of variation diagram of major, trace and rare earth elements. Basalts in the region of this study are plotted at the region of within plate basalt.