9527020 Dyar The proposed research is to study the mineralogy and petrology of certain carriers of boron in order to assess their role in the behavior of boron during high-grade metamorphism, migmatism and anatexis. The carriers to be studied include tourmaline, muscovite, sillimanite, kornerupine, grandidierite, and werdingite in metapelites in Western Maine. Special emphasis will be on assessing the role of aqueous fluid and anatectic melt in removing boron released by tourmaline breakdown. major element compositions will be determined by electron microprobe, Fe+2 and Fe+3 by Mossbauer spectroscopy, H in bulk samples by uranium extraction, H zoning by 15N reaction, bulk and microscopic B, Li and F microscopic measurements by ion microprobe. Results from this study will provide a detailed understanding of the B budget during high-grade metamorphism and provide important insights into the processes by which crystalline terranes are formed.
