Stable Isotope Laboratory

The UW–Madison Stable Isotope Laboratory is active in many areas of the Earth Sciences including studies of: the evolution of the crust and mantle, magma genesis, volcanology, migration of fluids in the crust, formation of base-metal ore deposits, diagenesis in sedimentary basins, carbon (re)cyling, diffusion rates in minerals, and reconstruction of paleoenvironments, climate change, and paleodiet. Recent projects have included the study of: zircons from the earliest Earth (Western Australia) to present, martian and lunar samples, mantle xenoliths, caldera volcanism at Yellowstone, the evolution of the Sierra Nevada batholith, and quartz overgrowths in the Saint Peter sandstone. The Stable Isotope Laboratory includes two dual-inlet five-collector Finnigan/MAT 251 mass-spectrometerstwo laser probe systems (Nd-YAG and CO2 lasers) for silicate, oxide, phosphate, and sulfide analysis; and conventional lines for analysis of silicates, oxides, sulfides, hydrous minerals (D/H), carbonates, graphite, and water. The laser fluorination lines yield high-precision oxygen isotope data for silicates and oxides which are used in studies focusing on topics which include: magma genesis, ancient hydrothermal alteration, isotope thermometry and speedometry, diffusion rates of oxygen in minerals, oxygen isotope heterogeneity in the mantle and the solar system.


John W. Valley
Charles R. Van Hise Professor
Stable Isotope Geochemistry and Metamorphic Petrology
(608) 263-5659