Open magmatic systems

Ozawa K. (2001) Mass balance equations for open magmatic systems trace element behavior and its application to open system melting in the upper mantle. J. Geophys. Res. 106, 13407-14434. 

The Rb-Sr systematics indicate that the flows as well as the dikes of Vestfjella originated in an open magmatic system in which the chemical composition of the magma was altered by interaction with the Precambrian basement rocks that were characterized by having higher Sr/ Sr ratios but lower strontium concentration than the mantle-derived basalt magma. 

Spera, F.J. and Bohrson, W.A., 2001. Energy-constrained open-system magmatic processes I general model and energy-constrained assimilation and fractional crystallization (EC-AFC) formulation. J. Petrol., 42 999-1018. 

Crustal melting and the effects of open-system magmatic behavior on U-series disequilibria... 

In particularly favorable cases, inferences about magma residence times can be derived from other isotopic systematics, most notably Rb- Sr (Davies et al., 1994 Halliday et al., 1989). Extremely evolved magmas can have sufficiently high Rb/Sr for Sr isotope signatures to evolve detectably on timescales commensurate with magmatic processes, enabhng the time since differentiation to high Rb/Sr to be delimited. Correlations between diverse Rb/Sr and Sr/ Sr in some suites of silicic lavas may be dominantly those of in situ decay rather than open-system processes, in which case they delimit the differentiation events... 

Black S., Macdonald R., Barreiro B. A., Dunkley P. N., and Smith M. (1998a) Open system alkaline magmatism in northern Kenya evidence from U-series disequilibria and radiogenic isotopes. Contrib. Mineral. Petrol. 131, 364-378. 

Gamble J. A., Wood C. P., Price R. C., Smith I. E. M., Stewart R. B., and Waight T. (1999) A fifty year perspective of magmatic evolution on Ruapehu Volcano, New Zealand verification of open-system behaviour in an arc volcano. Earth Planet. Sci. Lett. 170, 301-314. 

In order to achieve these aims, and to limit the length of the chapter, we have not provided a detailed review of theories regarding the origin of primitive arc basalts, the mixing of magmatic components derived from the upper mantle, aqueous fluids, and sediment melts, or open-system processes in the cmst including mixing and assimilation. For a more complete view of these theories, we refer the reader to the many excellent review papers and individual smdies that are, all too briefly, cited below. 

Gregory et al. 1989). Figure 13 plots 5 0(feldspar) vs. 5 0(pyroxene) for hydrothermally altered gabbros (Criss et al. 1987). Under equilibrium magmatic conditions, these minerals would have small high temperature fractionations falling along an array with slope = 1. The steeper slopes shown here result from open system hydrothermal alteration which has affected feldspar more extensively than pyroxene. 

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