Spinel mineral residues

Recasting the major-element compositions of experimental residues and mantle samples into a common set of mineral components effectively eliminates diff erences in temperatures and pressures of final equilibration, as the normalization essentially re-equilibrates all compositions to a common temperature and pressure. Here, we use the high P-T spinel and garnet Iherzolite... 

Figure 4 Normative spinel Iherzolite mineral abundances (wt.%) in batch partial melt extraction residues (0-25%) from fertile peridotite (composition 8, Table 1) as a function of Mg (molar Mg/(Fe + Mg)) at 0.5 GPa, 1 GPa, and 2 GPa, based on the melting model of Kinzler and Grove (1992a, 1993). Normative mineral compositions are calculated using the spinel Iherzolite normative algorithm of Kelemen et ai, (1992).

Normal mantle melting, such as that which leads to the formation of oceanic crust and oceanic islands, produces magma of basaltic to picritic composition and leaves a residue consisting of olivine, orthopyroxene, chnopyroxene and an aluminous phase. The compositions of minerals in this residue, and their relative proportions, are unlike those in old subcontinental hthosphere Mg-Fe ratios of the ferromagnesian minerals are too low, and the amount of chnopyroxene and spinel or garnet is too high. 

A. Saigal, E.R. Fuller, S. Jahanmir, Modeling of Residual Stresses and Mechanical Behavior of Glass-Infiltrated Spinel Ceramic Composites, Computational Modelling of Materials, Minerals and Metals Processing, (ed M. Cross, J.W. Evans and C. Bailey), TMS, (2001). 

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