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Origins of Clinopyroxenes in Alkaline Basalts from Jeju Island  

Yang Kyounghee (Geological Environmental Science Major, College of Natural Sciences, Pusan National University)
Hwang Byoung-Hoon (Geological Environmental Science Major, College of Natural Sciences, Pusan National University)
Publication Information
Journal of the Mineralogical Society of Korea / v.18, no.1, 2005 , pp. 33-43 More about this Journal
Abstract
Three types of clinopyroxenes in alkali basaltic rocks from Jeju Island can be identified on the basis of geochemical and textural data. Type Ⅰ is Cr-rich diopside in spinel peridotites from the upper mantle. Type Ⅱ is augite in fine-grained pyroxenites which are possibly either magmatic vein or metamorphic segregations owing to anatexis of the upper mantle. The augite of Type Ⅱ contains high Ca and Mg and relatively low Ti. Type Ⅲ is thought to be either cumulates or cognate phenocrysts and can be subdivided into Ⅲa, Ⅲb, and Ⅲc based on their occurrence mode. Clinopyroxenes of Type Ⅰ have the highest Mg# and Si and the lowest Ti, whereas those of Type Ⅲhave lower Mg#와 Si and higher Ti. These geochemical characteristics indicate that (Ti+Al/sup Ⅵ/)/Si and Al/sup Ⅵ//Al/sup Ⅵ/ increase from Type Ⅰ to Type Ⅲ. It is possibly interpreted that Type Ⅰ is of the highest pressure origin and Type Ⅲ of the lowest. Fractionation of high-pressure clinopyroxenes would result in evolved undersaturated alkali-enriched liquids, probably producing the alkali-enriched host basaltic rocks in Jeju Island.
Keywords
jeju island; mantle xenolith; clinopyroxenes; cumulates; upper mantle;
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  • Reference
1 Allegre, C.J. and Turcotte, D.L. (1986) Implications of a two-component marble-cake mantle. Nature, 323, 123-127   DOI   ScienceOn
2 Choi, S.-H. (1998) Geochemical study of ultramafic xenoliths in basalts from Cheju Island, Korea. Ph.D thesis, Seoul Nat'l Univ. 203p
3 Sachs, P.M. and Hansteen, H.T. (2001) Pleistocene underplating and metasomatism of the lowercontinental crust: a xenolith study. J. Petrol., 41, 331-356   DOI   ScienceOn
4 Tracy, R.J. (1980) Petrology and genetic significance of an ultramafic xenolith suite from Tahiti. Earth Planet. Sci. Lett., 48, 80-96   DOI   ScienceOn
5 Won, C.K., Lee, M.W., Lee, D.Y., and Shon, Y.K. (1993) Explanatory text of the geological map of Seongsan. Jeju Province Office. pp. 104
6 Chen, S., O'Reilly, S.Y., Zhou, X., William L. G., Zhang, G., Sun, M., Feng, J., and Zhang, M. (2001) Thermal and petrological structure of the lithosphere beneath Hannuoba, Sino-Korean craton, China: evidence from xenoliths. Lithos, 56, 267-301   DOI   ScienceOn
7 Thompson, R.H. (1974) Some high-pressure pyroxenes. Mineral. Mag., 39, 768-787   DOI
8 Yang, K. (2004) Fluid and melt inclusions trapped in xenoliths from the lower crust/upper mantle beneath Jeju Island (I): A preliminary study. J. Petrol. Soc. Korea, 13, 34-45
9 Yun, S.K., Han, D.S., and Lee, D.Y. (1986) Quaternary geological survey of southern Jeju Island. KIGAM, KR-86-2(B)-2, pp. 64
10 Frey, F.A. and Prinz, M. (1978) Ultramafic inclusions from San Carlos, Arizona: Petrologic and geochemical data bearing their petrogenesis. Earth Planet. Sci. Lett. 38., 129-176   DOI   ScienceOn
11 대한지질학회 (1999) 한국의 지질. 802p
12 Geol. Soc. Am. Bull., Kim, K.H., Nagao, K., Suzuki, K., Tanaka, T., and Park, E.J. (2003) Radiometric ages and Nd-Sr isotopes of granitic rocks in Jeju volcanic Island, South Korea: evidences of presence of continental basement. Proceedings of the 1st Symposium, Jeju Volcanological Institute, 26-32
13 Frey, F.A. and Green, D.H. (1974) The mineralogy, geochemistry and origin of lherzolite inclusions in Victorian basanites. Geochim. Cosmochim. Acta, 38, 1023-1059   DOI   ScienceOn
14 Irving, A.J. (1974) Megacrysts from the newer basalts and other basaltic rocks of southeastern Australia. Geol. Soc. Am. Bull., 85, 1503-1514   DOI
15 Kovacs, I., Zajacz, Z., and Szabo, C. (2003) Type- II xenoliths and metasomatism beneath the NogradGomor volcanic field, Carpathian-Pannonian region. Proceedings of 2003 Korea-Hungary International Joint Seminar, 62-68
16 윤성효, 고정선, 안지영 (1998) 제주도 동부 알칼리 현무암내 스피넬-레졸라이트 포획체의 연구. 자원환경지질, 31권 5호, 447-458
17 이문원, 원종관, 이동영, 박계헌, 김문섭 (1994) 제주도 화산암류의 화산층서 및 암석학적 연구. 지질학회지, 30, 521-541
18 McBirney, R.B. (1993) Igneous petrology (2nd ed), Jones and Bartlett Publishers, 580p
19 Mukasa, S.B. and Shervais J.W. (1999) Growth of subcontinental lithosphere: evidence from repeated dike injections in the Balmuccia lherzolite massif, Italian Alps. Lithos., 48, 287-316   DOI   ScienceOn
20 Velde, B. and Kushiro, I. (1978) Structure of sodium alumino-silica melts quenched at high pressure; infrared and aluminium K-radiation data. Earth Planet. Sci. Lett., 4, 137-140
21 Mercier J.C.C. and Nicolas A. (1975) Textures and fabrics of upper-mantle peridotites as illustrated by xenoliths form basalts. J. Petrol., 16. 454-487