This award will enable Dr. R. Gordon Gastil of San Diego State University to collaborate with Dr. Masaaki Shimizu of the University of Tokyo and Dr. Shunso Ishihara of the Geological Survey of Japan. Dr. Gastil will visit sites in Japan where exposed granitic rocks have been subjected to detailed mapping and geochemical analysis. These rock formations will be compared with those of the California Peninsula as to the degree and significance of asymmetry and internal structure, and the meaning of the magnetite/ilmenite boundary. Comparative analyses of granitic rock structures from different geographic locations will further the interpretation of magma development in subducting tectonic environments, and thus help to unravel the origin and evolution of the major types of granitic rock. Dr. Gastil has extensive experience in mapping the large zoned plutons of the California Peninsula. Dr. Ishihara is considered the world authority on the magnetite/ilmenite distinction in granitic terranes, and Dr. Shimizu has recently published what is probably the most detailed study of this distinction within a single pluton. Thus, the research will benefit significantly from the complementary experience of the researchers.
