Plutons represent addition of magma to the crust, at least at the level of intrusion, and as many plutons are quite large, space must be provided in the crust to accommodate the increased volume. The space problem has been identified for a long time, but its resolution has become increasingly important as pluton emplacement mechanisms are studied. This project will examine the idea that volume loss of the host rocks surrounding a pluton may accommodate some of the required space. The approach is a chemical mass-balance study of wall rocks around the Cretaceous aged La Posta pluton in southern California. Results should test this hypothesis for how space is provided for intruded plutons.
