Evidences of the presence of old continental basement in Cheju volcanic Island, South Korea, revealed by radiometric ages and Nd-Sr isotopes of granitic rocks.

Abstract

Major and trace element and Nd-Sr isotopic data are presented on the granitic rocks known as a basement in the Cheju volcanic island, together with CHIME age data on porphyritic hornblende-biotite granite xenolith from the Byeoldobong area.The CHIME ages from zircon and allanite grains of porphyritic hornblende-biotite granite were determined to be 169 ± 29 Ma and 183 ± 40 Ma, respectively, which are corresponding to a Jurassic age. It is concordant with a K-Ar age of 172.4 ± 5

Present-day relative displacements between the Jeju Island and the Korean peninsula as seen from GPS observations

“…Moreover the geological evidence provides that the Jeju Island basement is similar to that of the Korean peninsula (e.g. Kim et al, 2002).…”

“…The combined geochemical and Nd-Sr isotopical characteristics and radiometric ages of the granitic rocks from Jeju Island indicate that the basement of the island is correlated with the Okchan zone ( Fig. 1) (Kim et al, 2002), and they conclude that the Okchan zone (in the Korean peninsula) is continuously extended to the Jeju Island.…”

Composition and Evolution of Lithosphere Beneath the Jeju Island Region (I): A Review

“…현재 제 주도는 한반도 육지부와 마찬가지로 유라시아판에 위 치하며, 국부적인 판내부 열곡시스템 환경에 놓여 있 다 (Hamdy et al, 2004). 신생대 배호분지인 동해분지와 남쪽의 제주분지가 열리기 전(27-15 Ma)의 제주도는 한반도와 동일한 지 구조 환경에 놓여 있었으며, 백악기말-제3기초에 한 반도 남부지역과 동일한 섭입대 관련 칼크-알칼리 마 그마활동을 경험했다 (Sibuet et al, 1987;Lee et al, 1987;Kim et al, 2003). 이러한 칼크-알칼리 마그마활동을 나타내는 노두는 제주도 지표에 노출되 어 있지 않다.…”

Oxygen Isotopic Ratios for Ultramafic Xenoliths from the Korean Peninsula

“…1). (Lee, 1996;Choi et al, 2001Choi et al, , 2002Kim et al, 2002Kim et al, , 2005Kil, 2006Kil, , 2007Chen et al, 2007).…”