Systematic studies of tourmaline are proposed to extend the utility of this mineral as a petrogenetic indicator in a wide range of metamorphic rocks. Field-related studies will be conducted on samples from NW Maine where the PIs have already characterized conditions of metamorphism. Specific goals include: (1) assessment of compositional relations between tourmaline rims and bulk rocks, mineral assemblage, and T, (2) relations between metamorphic history and tourmaline zoning patterns, (3) utilization of compositions of detrital tourmalines to indicate sedimentary provenance, and (4) relations of compositions of authigenic tourmalines and diagenetic fluids. These studies will also lead to a better understanding of the crystal chemistry of tourmalines, geochemical cycles of B, and metamorphic processes.
