2 ( ) 6, Fe - Mg, (850 C,9.0 kbar )( Ren et al.,1992 )1992g1993,, 2 2 2, (Larsemann Hills ) Ingrid Christensen,, 60km 2, Mirror ( 1), 5 (Zhao et al.,1

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1 6 3 ( ) Vol.6, No ANTARCTIC RESEARCH (CHINESE EDITION ) September 1994 Ξ (, ) (, ),,, : + +, C kbar, 2 2 2, (1), (1) Vestfold (Black et al.,1991 ) ; (2) ( 10 ), Rauer (Harley,1988; Kinny et al.,1992 ) ; (3), (Zhao et al.,1992; Zhou and Hensen,1992 ). St we et al. (1989) 10,, 750 C, 4.5 kbar ΞΞ, ( 5 )( Zhao et al.,1992 ),,,, Ξ Ξ ( ) 1bar =10 5 Pa

2 2 ( ) 6, Fe - Mg, (850 C,9.0 kbar )( Ren et al.,1992 )1992g1993,, 2 2 2, (Larsemann Hills ) Ingrid Christensen,, 60km 2, Mirror ( 1), 5 (Zhao et al.,1992; Zhou and Hensen,1992 ),, St we and Powell (1989) 750 C 4.5 kbar, kbar Carson et al. (1993), D 2, S2 NW, S2, F 2 D 2, D 3,,,, L 3X 2, 2, 1m,,, : 2 2 2, Mir 2 ror Broknes Manning, : () 2, Mirror Fisher Sigdor Stornes Kaiven Steinnes,, , 10 5 Stornes , , , , , , , , , Mirror, SΥstrene, Steinnes, A Bollingen Stor y, , Bollin 2

3 3 : 3 1 Mirror 1. ;2. Al Fe ;3. ;4. ;5. ;6. ;7. ;8. ;9. ;10. Fig.1. Geologic map of the Mirror Peninsula in the Larsemann Hills.1. mafic granulite ;2. high 2Al 2 Fe 2gneiss ;3. banded gneiss ;4. syenogranite ;5. Grt 2bearing granitic gneiss ;6. granitic gneiss ; 7. migmatitic gneiss ;8. coarse garnet ;9. leucogneiss ;10. sample locality. gen Sydney

4 4 ( ) , SiO Al 2O 32CaO 2MgO ( Coleman, 1977 ), : Mirror ;+ Bollingen ; SΥstrene Fig.2. Al 2O 32CaO 2MgO plot (with fields after coleman,1977 ) showing the distribu 2 tion of the mafic to ultramafic boudins from the Mirror Peninsula ( ), Bollin 2 gen Island (+ ), SΥstrene Island ( ) %, SΥstrene Bollingen,Mirror Al 2O 3, MgO, MgO gmgo + FeO (wt % ), Zr Mirror Cr, Ti g 110 (Sun and Nesbitt,1977 ), SΥstrene Bollingen Ti gzr 2., Cr ppm Ni ppm,,al 2O 32CaO 2MgO ( 2) 2, REE, ppm, , LREE ghree , Eu ,, La N gybn , g,, Cpx 2Opx 2Hbl 2Pl 2Bt, , , 3 g Fig.3. Chondrite 2normalised REE pattern for g 2type mafic granulite rocks.

5 3 : , , , ,, La N gybn , Eu g,, g, Cpx 2Pl 2Bt 2Hbl,,, 4, LREE, HREE,La N gybn Eu, Eu 2+ g,, g, Opx 2Cpx 2Hbl 2Bt 2 Pl, 4,,La N gybn 1.55 Ti g Zr =110, Ti gzr 110 (Sun and Nesbitt,1977 ), 1 Table 1.Whole rock geochemical data for mafic granulite rocks from the Larsemann Hills and adjacent area. Mirror Peninsula SΥstrene Island Bolingen Island A SiO TiO Al 2O Fe 2O FeO MnO MgO CaO Na 2O K2O P2O SO H 2O H 2O CO , ppm Ba Cr Cu Ga Nb Ni Pb Rb Sr Ti V Y Zn Zr MgO gmgo + FeO Ti gzr Ti gy , , X, -,32842 St we,1989, A Thost et al.,1992.

6 6 ( ) 6 2 Table 2. Rare earth element contents for mafic granulite rocks from the Larsemann Hills area La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu < < REE LREE ghree Eu La N gybn ICP 4 g g Fig.4. Chondrite 2normalised REE pattern for g 2type and g 2type mafic granulite rocks., 34,

7 3 : 7 Mirror , Al 2O wt %, XM g , XM g , XA n , ,,, XM g , XM g Steinnes , XM g , XM g , XA n , Sydney XM g , XM g , XM g 0.543, XA n= , 3 Table 3. Mineral assemblage of the mafic granulite rocks. Sample Grt Opx Cpx Pl Hbl Bt Qtz (+ ) (++ ) (- ),,, : + (Clark & Powell,1991; Nichols & Berry,1991 ),, 1992g1993, Mirror ,, : + +,, 5 Mirror Harley (1984) 2 Fe 2Mg, 2 2 2, PN P Newton & Perkin (1982) 5, M 1 T = C, P= kbar Sydney (5), T = C, P=6.2 1kbar, Motoyoshi et al. (1991), P2T (T =760 C, P=6 kbar ), Grt 2Opx 2Pl 2Qtz

8 8 ( ) 6 4 Table 4. Electron microprobe analysis of minerals of mafic granulite rocks from the Larsemann Hills and adjacent area. Mirror Opx Ga pl Cpx Opx a b a b a b c d e SiO TiO Al 2O Cr 2O FeO MnO MgO Na 2O K2O CaO Total O Si Al Ti Cr Fe Mn Mg Ca Na K Cations Mg gmg + Fe XA n XA b XO r Steinnes Sydney Opx Bio pl Opx Ga pl Bio f g h i j k L m L m L m L SiO TiO Al 2O Cr 2O FeO MnO MgO Na 2O K2O CaO Total O Si Al Ti Cr Fe Mn Mg Ca Na K Cations Mg gmg + Fe XA n XA b XO r

9 3 : 9 5 Table 5. Thermobarometry of mafic granulife rocks. Larsemann Hills Sydney Island Grt 2Bt Grt 2Opx T 1 T 2 T 3 T 4 TH T SB PRef P 1 P 2 P 3 P 4 P 5 T Ref a b a b T 1- Ferry & Spear,1978; T 2- Hodges & Spear,1982; T 3- Ghent & Stout,1981; T 4- Dasgupta et al.,1991; TH- Harley,1985; T SB - Sen & Bhatt,1984; P 1 - Newton & perkins, ( 1982 ) +1.8 Kb ; P 2 - Bohlen, Wall and Boettcher,1983; P 3- Mg, Newton & Chippera,1985; P 4- Fe, Newton & Chippera,1985; P5- Fe, Moecher, Essene & Anovitz,1988; PRef- (kbar ) ; TRef- ( C) 1.,, ( 1), Cr Ni,, ( ), : (1), ; (2) ; (3),,, (1),,,, (3),,,,,,, Vestfold (Dirks et al.,1993 ),,, 2.,,, 2 2 2, L 3X, 750 C,6.3 kbar,,, (1993)

10 01 ( ) , SmgNd Ma,, 1992g1993, [ ] (1993) : Sm2Nd, ( ),5 (2), Blac k, L. P., Kinny, P. D., Sheraton, J. W. and Delor, C. P. (1991) : Rapid production and evolution of Late Archaean felsic crust in the Vestfold Block of East Antarctica, Precambrian Research,50, Cars on, C. J., Dirks, P. H. G. M. and Wilson, C. J. L. (1993) : Proterozoic tectonic evolution of the Larsemann Hills, East Antarctica, in abstracts, the tectonics of East Antarctica, Institute of Earth Sciences, University of Utrecht, the Netherlands. Clar k, G. L. and Powell, R. (1991) : Decompressional coronas and symplectites in granulites of the Musgrave Complex, Central Australia, Journal of Metamorphic Geology,9, Coleman, R. G. (1977) : Ophiolites, New York, Springer Verlag,229. Dirk s, P. H. G. M., Carson, C. J. and Wilson, C. J. L. (1993) : The deformational history of the Larsemann Hills, Prydz Bay: the importance of the pan 2African (500Ma ) in East Antarctica, Antarctic Science,5 (2), Harl ey, S. L. (1984) : An experimental study of the partitioning of Fe and Mg between garnet and orthopyroxene, Con2 tributions to Mineralogy and Petrology,86, Harl ey, S. L. (1988) : Proterozoic granulites from the Rauer Group, East Antarctica, İ Decompressional pressure 2tem2 perature paths deduced from mafic and felsic gneiss, Journal of Petrology,29, Kinn y, P. D., Blach, L. P. and Sheraton, J. W. (1992 ) : Zircon ages and the distribution of Archean and proterozoic rocks in the Rauer Islands, Antarctic Science,4. Mann ing,d. A. C. and Pichavant, M. (1983 ) : The role of fluorine and boron in the generation of granitic melts, In: Migmatites,melting and metamorphism, Ed. by Atherton,M. P. and Gribble, C. D., Cheshire, Shiva, Moto yoshi, Y., Thost, D. E. and Hensen, B. J. (1991) : Reaction textures in calc2silicate granulites from the Bollingen Islands, Prydz Bay, East Antarctica : implications for the retrograde P2T path, Journal of Metamorphic Geology,9, Newt on, R. C. and Perkins, D. İ İ İ (1982) : Thermodynamics calibrations of geobarometers based on the assemblages garnet 2plagioclase 2orthopyroxene (clinopyroxene ) 2quartz,American Mineralogist,67, Nich ols, G. T. and Berry, R. F. (1991) : A decompressional P2T path, Reinbolt Hills, East Antarctica, Journal of Meta 2 morphic Geology,9, Ren, L., Zhao, Y., Liu, X. and Chen, T. (1992) : Reexamination of the metamorphic evolution of the Larsemann Hills, East Antarctica, In: Recent Progress in Antarctic Earth Science, Ed. by Yoshida, Y., et al., Sher aton, J. W. and Black, L. P. (1988) : Chemical evolution of granitic rocks in the East Antarctic Shield, with particu 2 lar reference to post - orogenic granites, Lithos,21, St w e, K., Braun, H. M. and Peer, H. (1989): Geology and structure of the Larsemann Hills area, East Antarctica, Australian Journal of Earth Sciences,36, St w e, K. and Powell, R. ( 1989 ) : Low pressure granulite facies metamorphism in the Larsemann Hills area, East Antarctica, petrology and tectonic implications for the Prydz Bay area, Journal of Metamorphic Geology,7, Sun, S. S. and Nesbitt, R. W. ( 1977 ) : Chemical heterogeneity of the Archean mantle, composition of the earth and mantle evolution, Earth Planet. Sci. Lett.,35, Thos t, D. E., Motoyoshi, Y. and Hensen, B. J. (1992) : Mode of occurrence, Geochemistry and mineral textures of maf 2 ic to ultramafic rocks from the Bollingen Islands, Prydz Bay, East Antarctica, In: Recent Progress in Antarctic Earth Science, Ed. by Yoshida, Y. et al.,

11 3 : 11 Wang, Y., Zhao, Y., Ren, L. and Chen, T. (1993) : Geological and Geochemical characteristics of metamorphic rocks from the Larsemann Hills, East Antarctica, in abstracts, the tectonics of East Antarctica, Institute of Earth Sci2 ences,university of Utrecht, the Netherlands. Zhao, Y., Song, B., Wang, Y., Ren, L., Li, J. and Chen, T. (1992): Geochronology of the granite in the Larsemann Hills, East Antarctica, In: Recent Progress in Antarctic Earth Science, Ed. by Yoshida, Y. et al., Zhou, B. and Hensen, B. J. (1992) : SmgNd isotopic analysis of garnet : Constraints on the metamorphic histories of the Prydz Bay and northern Prince Charles Mountains granulite terranes, Antarctica, in abstracts, the application of geochronology to field related problems, Geological Society of Australia SGGMP Workship, Alice Springs, Aus 2 tralia. GEOCHEMICAL CHARACTERISTICS AND MEDIUM PRESSURE GRANULITE FACIES METAMOPHISM OF MAFIC GRANULITE ROCKS FROM THE LARSEMANN HILLS, EAST ANTARCTICA Wang Yanbin, Zhao Yue, Ren Liudong, Chen Tingyu ( Institute of Geology, C. A. G. S., Beijing ) Liu Xiaohan, Tong Laixi ( Institute of Geology,Academia Sinica,Beijing ) Abstract Oriented distributed mafic granulite lenses, pods and boudins occur in metapelitic and leucogneiss in the Larsemann Hills, Prydz Bay, East Antarctica. The geochemical characteristic of the rocks imply that they are chemically similar to mafic cumulate. They probably represent remnants of mafic dykes. In the Mirror peninsula orthopyroxene 2pla 2 gioclase symplectites aroud garnet in mafic granulite is discovered, orthopyroxene and plagioclase form by the reaction garnet + quartz plagioclase + orthopyroxene Average pressure calculation on the assemblage indicates the prevailing conditions were kbar at C. It is the first pressure estimate in the light of the equi2 librium assemblage garnet 2orthopyroxene 2plagioclase 2quartz. An earlier medium pres 2 sure granulite facies event in the Larsemann Hills is confirmed. Key words medium pressure granulite facies metamorphism,mafic granulite rocks, geo2 chemistry, East Antarctica.

GeologicalScienceandTechnologyInformation Vol.37 No.2 Mar doi: /j.cnki.dzkq ,,,. [J].,2018,37(2):71-78.,,,, (, 62100

37 2 2018 3 GeologicalScienceandTechnologyInformation Vol.37 No.2 Mar. 2018 doi:10.19509/j.cnki.dzkq.2018.0210. [J]. 201837(2):71-78. ( 621000) : (CIA) (ICV) - : ; ; ; ; :P534.51 :A :1000-7849(2018)02-0071-08