9528787 Macdougall This grant provides $301,000 as partial support of the costs of acquiring a new thermal ionization mass spectrometer (TIMS) with high abundance sensitivity, multiple collectors and negative ion capabilities. Scripps Institute of Oceanography will provide 40% of the total equipment acquisition costs. This instrument will allow these investigators to continue there present work is applied isotope geochemistry as well as expand into systems which require the mass resolution and negative ion capabilities for which their current single collector TIMS is not suitable. These increased capabilities include, Re/Os isotope systematics of marine sediments which have implications for paleotectonics, climate, weathering and oceanic hydrothermal activity, and U/Th series isotopes in igneous rocks, which can be used to gain insight into the time scales and processes of magma genesis and transport as well as the chemical composition of source materials for mid-ocean ridge basalts, island arc andesites and rocks from other tectonic settings. ***
