An early Proterozoic leuco-granitic gneiss with the REE tetrad phenomenon

Geochemistry of Nd and Ce isotopes and REE abundances in Precambrian orthogneiss clasts from the Kamiaso conglomerate, central Japan.

“…In contrast to the Chinese Precambrian rocks, the Korean Precambrian rocks have sporadically been studied, mainly by Rb-Sr and U-Pb methods (Gaudette and Hurley, 1973;Na and Lee, 1973;Na et al, 1982;Choo and Kim, 1985). Recently a Sm-Nd age of 2.25 Ga with 8Nd (2.25 Ga) = -5.7 has been reported for a leuco-granitic gneiss in the Samchcog area of the Sobaegsan (Yongnam) Massif, South Korea (Lee et al, 1994) (Fig. 6).…”

“…Data of Chinese samples are from Jahn (1990a, b); Jahn and Ernst (1990) and Jahn et al (1987Jahn et al ( , 1988. Data of Korean sample are from Lee et al (1994). Geochronological data on Rb-Sr and K-Ar systems by Shibata and Adachi (1974), Th-U-to tal Pb system by Adachi and Suzuki (1993) and our Sm-Nd system indicate that the original gra nitic rocks for the Kamiaso gneisses were emplaced at 2.07 Ga and underwent regional metamorphism at 1.8-1.6 Ga.…”

Tetrad effects and fine structures of REE abundance patterns of granitic and rhyolitic rocks: ICP-AES determinations of REE and Y in eight GSJ reference rocks.

“…In particular, it is well-known that REE abundances in volcanic rocks when normalized by chondrite usually dis play simple linear patterns with or without breaks or smoothly curved ones. In this context, the re ported tetrad effects in chondrite-normalized pat terns particularly for leuco-granitic rocks and gneisses Masuda and Akagi, 1989;Lee et al, 1994) are indeed challenging the paradigm in the present stage of REE geochemis try.…”

Rare Earth Element, Sm-Nd and Rb-Sr Age and its Geochemical Implication of Leucogranite in the Deokgu Hot Spring Area, Yeongnam Massif, Korea

“…영남육괴 북동부는 한반도 남부에서 원생대초기 화 성활동과 관련된 지질학적, 지구화학적 연구결과가 활 발하게 보고된 지역이다 (Lee et al, 1994(Lee et al, , 2005(Lee et al, , 2010김용준과 이대성, 1983;김남훈 외, 2002강지훈 외, 2004, 2006정창식 외, 2004;정원석, 나기창, 2008;정원석 외, 2009;이호선 외, 2010). Lee et al (2005)은 영남육괴 북동부 농거리와 내덕 리 화강암의 Nd 동위원소의 초기치를 토대로 영남육 Masuda, 1975 (Fig.…”