Документ взят из кэша поисковой машины. Адрес оригинального документа : http://geo.web.ru/~ariskin/docs/papers/a_2009_kachkanar_ariskin.pdf Дата изменения: Wed Oct 6 10:39:59 2010 Дата индексирования: Fri Feb 11 12:59:59 2011 Кодировка:

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- ..*, ..**, ..***, ..*, ..* * , , e-mail: ariskin@rambler.ru ** , , e-mail: l.dan@utas.edu.au *** , , e-mail: konn@iem.ac.ru USE OF OLIVINE CONTROL LINES AND THE COMAGMAT MODEL FOR EVALUATION OF THE PARENTAL MAGMA COMPOSITION OF THE IOKO-DOVYREN LAYERED INTRUSION Ariskin A.A.*, Danyushevsky L.V.**, Konnikov E.G.***, Barmina G.S.*, Nikolaev G.S.* *Institute of Geochemistry and Analytical Chemistry RAS, Moscow, Russia e-mail: ariskin@rambler.ru **University of Tasmania (CODES), Hobart, Australia e-mail: l.dan@utas.edu.au ***Institute of Experimental Mineralogy RAS, Chernogolovka, Moscow region, Russia e-mail: konn@iem.ac.ru Several methods approaching initial melt composition and other parameters of a magma parental to the Ioko-Dovyren dunite-troctolite-gabbro-norite massif in Nothern Transbaikalia Region have been considered. Providing a closed magma chamber, the most accurate estimates were shown to follow from a combination of olivine control lines with results of calculations simulating equilibrium crystallization of chilled picrodolerites and contact Pl-lherzolites. Based on the results the Dovyren magma seemed to bring a significant amount of intratelluric olivine of ~Fo85-88 into the magma chamber and its bulk composition corresponds to Ol-gabbronorites containing ~20 .% MgO. The initial melt composition of the magmatic suspension is consistent with magnesium basites containing of 11 wt% MgO. Probable temperature of the parental magma was not exceeded 1300°. . (1) , . - [1-3]. MgO (19-25 .%), Ol. . 1 [2]. [4]. (2) . [5, 6] ( 4 6 . 1). (3) () . ( 200 ), . (~10% MgO) (25-30% MgO) [3, 7]. 1:3, 24 .% MgO. . Ol­ [8] - (. 1) , ~Fo94. Ol , Fo82-87 [3],
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The third international conference «Mafic-ultramafic complexes of fold ed regions and related d eposits»

1 « » - -

. 100 .%. F ­ % . , .

. [4]. [2] , Fo85 ( Ol ) (Ol±Pl) , 1180-1190° (. 1). [5] - [8]. :
m

C

i

fl C

i l


j 1

f

j

C ij ,

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Ci , Ci l Ci j ­ i- , (1 j m), fl fj ­ . , [5] , . (1340) , ~Fo-90 (. 1). , [5] , 90-95% [9]. , - Ol, [4].
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. - [6]. [8] , «» , , . - , ~20% Ol (. 1). 1400°, (17-18 .% MgO), ~Fo91. , - . -Mg (17.2% MgO) (14.5% MgO), 1400-1340° Fo91-90 [5,6], (~7.5% MgO), ~1185° Fo85 [4]. , 20% 50% . . , , . , , (1) :

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i

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. 1. () () - 59


The third international conference «Mafic-ultramafic complexes of fold ed regions and related d eposits»

Ol, ( Ol ­ ) [10]. , «» , , [11]. . 1 Ol-, (~15 ) , ~150 . , , Fo88 11 .% MgO. Pl- , (~8-10 .% MgO) (85-87% Fo). «»- «» . . 1 Ol ­ , [4-6]. , . [5] [6] «» , FeO. , , ( 2-3 .%) FeO .
1. .. . .: , 1983. 248 . 2. .., .., .. . - -- ( ) // . 1980. . 250. .5. . 12281232. 3. .. - . -: . , 1998. 264 . 4. .., .., .. ( , ) // . 2003. 2. . 131-155. 5. .., .., - .. - , // . 2007. 6. . 579-598. 6. .. - - // . . . . « ». : , 2006. . 132-133. 7. .. - . : , 1986. 127 . 8. .., .. . (. .. ). .: . 2000. 363 . 9. .., .., .., .., .., .., .., .. (2009) : - // . [ ]. 10. .., .. - : II. // . 2005. 7. . 712-732. 11. Barnes S.J. The effect of trapped liquid crystallization on cumulus mineral compositions in layered intrusions // Contrib. Mineral. Petrol. 1986. V. 93. P. 524-531.

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