PRESSURE-DEPENDENCE OF NICKEL PARTITIONING BETWEEN FORSTERITE AND ALUMINOUS SILICATE MELTS

被引:34
作者
MYSEN, BO
KUSHIRO, I
机构
[1] Geophysical Laboratory, Carnegie Institution of Washington, Washington
关键词
D O I
10.1016/0012-821X(79)90047-5
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Nickel partitioning between forsterite and aluminosilicate melt of fixed bulk composition has been determined at 1300°C to 20 kbar pressure. The value of the forsterite-liquid nickel partition coefficient is lowered from >20 at pressures equal to or less than 15 kbar to <10 at pressures above 15 kbar. Published data indicate that melts on the join Na2O-Al2O3-SiO2 become depolymerized in the pressure range 10-20 kbar as a result of Al shifting from four-coordination at low pressure to higher coordination as the pressure is increased. This coordination shift results in a decreasing number of bridging oxygens in the melt. It is suggested that the activity coefficient of nickel decreases with this decrease in the number of bridging oxygens. As a result, the nickel partition coefficient for olivine and liquid is lowered. Magma genesis in the upper mantle occurs in the pressure range where the suggested change in aluminum coordination occurs in silicate melts. It is suggested, therefore, that data on nickel partitioning obtained at low pressure are not applicable to calculation of the nickel distribution between crystals and melts during partial melting in the upper mantle. Application of high-pressure experimental data determined here for Al-rich melts to the partial melting process indicates that the melts would contain about twice as much nickel as indicated by the data for the low-pressure experiments. If, as suggested here, the polymerization with pressure is related to the Al content of the melt, the difference in the crystal-liquid partition coefficient for nickel at low and high pressure is reduced with decreasing Al content of the melt. Consequently, the change of DNiol-andesite melt is greater than that of DNiol-basalt melt, for example. © 1979.
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页码:383 / 388
页数:6
相关论文
共 22 条
[1]   SOME BASALTIC AND ANDESITIC GASES [J].
ANDERSON, AT .
REVIEWS OF GEOPHYSICS, 1975, 13 (01) :37-55
[2]  
Arndt NT., 1977, Year Book - Carnegie Institution of Washington, P553
[3]   COORDINATION NUMBER OF FERROUS IONS IN SILICATE-GLASSES [J].
BOON, JA ;
FYFE, WS .
CHEMICAL GEOLOGY, 1972, 10 (04) :287-298
[4]   VISCOSITY OF MAGMATIC SILICATE LIQUIDS - MODEL FOR CALCULATION [J].
BOTTINGA, Y ;
WEILL, DF .
AMERICAN JOURNAL OF SCIENCE, 1972, 272 (05) :438-&
[5]   APPARATUS FOR PHASE-EQUILIBRIUM MEASUREMENTS AT PRESSURES UP TO 50-KILOBARS AND TEMPERATURES UP TO 1750-DEGREES-C [J].
BOYD, FR ;
ENGLAND, JL .
JOURNAL OF GEOPHYSICAL RESEARCH, 1960, 65 (02) :741-748
[6]  
BURNS RG, 1964, SCIENCE, V146, P1001
[7]   ATLANTIC-OCEAN FLOOR - GEOCHEMISTRY AND PETROLOGY OF BASALTS FROM LEGS 2 AND 3 OF DEEP-SEA DRILLING PROJECT [J].
FREY, FA ;
BRYAN, WB ;
THOMPSON, G .
JOURNAL OF GEOPHYSICAL RESEARCH, 1974, 79 (35) :5507-5527
[9]   NICKEL PARTITIONING BETWEEN OLIVINE AND SILICATE MELT [J].
HART, SR ;
DAVIS, KE .
EARTH AND PLANETARY SCIENCE LETTERS, 1978, 40 (02) :203-219
[10]  
Irvine T.N., 1976, Yearb. Carnegie Inst. Wash, V75, P668