This project is designed to test whether Cu and other chemical components are leached from wallrock during deep sodic-calcic alteration in the Yerington porphyry. It will involve geologic mapping and petrologic phase equilibria studies of sodic-calcic alteration. S, Sr, O, and Nd isotopic compositions in fresh and altered rocks will be used as tracers to constrain whether these fluids and components originated inside or outside the batholith. Integration of volumes of alteration and gains or losses should yield a mass-balance estimate of wallrock leaching of Cu, Fe, Zn, Au, K, and other components and allow assessment of their contribution to the Cu ore body.
