The formation of granitic pegmatites from the viewpoint of melt and fluid inclusions and new experimental work

This paper focuses on critical issues in the formation of pegmatites, and is based mainly on the study of melt and fluid inclusions in minerals, since these provide vital evidence for liquid compositions and phase relations in nature. The development of analytical methods are a prerequisite for the understanding of pegmatite-forming processes, especially for the determination of water concentrations in melt inclusions, as it is now clear that water is a major component in the formation of pegmatites. Furthermore, we can demonstrate that complete miscibility between pegmatite-forming melts and water exist above 700°C and 1 kbar. Hydrothermal anvil cell experiments provide key evidence to support our deductions by demonstrating the contrasting high and low pressure behavior of peralkaline melt fractions.

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