Phosphorus and rubidium in alkali feldspars -tools for better understanding of the late- to post-magmatic evolution of fractionated granites

摘要

Absolute contents and distribution patterns of phosphorus and rubidium in alkali feldspars were studied in detail in two peraluminous granite systems being quite different in intensity of influence of the late-to post-magmatic fluids - Podlesi (Bohemia) and Beauvoir (France). Rubidium is firmly bound in the Kfs-lattice and preserves well its magmatic signature during post-magmatic processes. In contrast, phosphorus can be easily released from the feldspar lattice and P-content serves as a sensitive indicator of the late- and/or post-magmatic fluid-related reactions.