System granite

The extent to which isotopic fractionation occurs at sub-1000°C temperatures in magmatic and regional metamorphic systems is unstudied in detail, but limited natural and experimental data in granitic systems suggest that measurable fractionation may occur under these conditions. This fractionation might be applied in studies of magmatic and ore evolution, either for thermometry or mineral deposit exploration. 

Differences between the observed distribution coefficients of a certain element at different concentrations are small. The only significant exception is Cs which has a higher distribution coefficient at low concentration than at high in the granite system (by a factor of less than two). This may in fact reflect the poor ion exchange capacity of the granite. 

Puziewicz J, Joharmes W (1990) Experimental study of a biotite-bearing granitic system under water-saturated and water-undersatrrrated conditions. Contrib Mineral Petrol 104 397-406 Radoslovich EW (1960) The structrrre of muscovite, KAl2(Si3Al)Oio(OH)2. Acta Crystallogr 13 919-932 Radoslovich EW (1961) Strrface symmetry and cell dimertsions of layer lattice silicates. Nature 191 67-68 Radoslovich EW, Norrish K (1962) The cell dimensiorts and symmetry of layer-lattice silicates. I. Some stractural consideratiorrs. Am Mineral 47 599-616... 

The normative albite-oithodase-quartz diagram — the granite system ... 

Experiments by Schairer (1950), Hamilton and MacICeime (1965), Taylor and MacKenzie (1975) and Morse (1969) have determined the positions of the nepheline syenite minima at pressures of 1 atm, 1 kb, 2 kb and 5 kb, respectively, ill the water-saturated system. These data are presented in Figure 3.25 as QFW normative wt %, in a projection from H2O onm the anhydrous base of the system, the plane nepheline-lralsUite-stUca. Unfike the granite system, the jposition of the... 

Johannes W., 1980, Metascable meldng in the granite system C -Or—Ab-An-H20. Contrib. Minerai Petrol., 72, 73-80. 

The granite system diagram is shown as a polythermal projection in Figure 17.35. 

The difference lies in the fact that the granite system is not the dry system q-ab-or, but the wet system q-ab-or-H20. The presence of water at high... 

Figure 17.36 The granite system at pressures from 0.5 to 10 kbar. The plus signs show the position of the ternary minimum at 0.5, 2, 3, and 4 kbar. The circle shows the position of the ternary eutectic at 5 kbar.

In a phenocryst-matrix study, LaTourette and Burnett [77] report that, in a natural granitic system, Du < 24. 

Grimaud, D., Beaucaire, C. Michard, G. 1990. Modelling of the groundwaters in a granite system at low temperature the Stripa groundwaters (Sweden). Applied Geochemistry, 5, 515-525. 

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