This award supports cooperative research in the origin of ore deposits to be conducted by Ian Lange of the University of Montana and Roman Tejada, Chief Geologist of the Compania Minera in Lima, Peru. They will study the San Vicente zinc-lead deposit which occurs in shallow water-deposited Triassic carbonate shelf rocks. Preliminary data support a model of hydrothermal replacement of laminated carbonate-evaporites. This will be tested, first by reconnaissance and detailed mapping jointly by Lange and his Peruvian host. Subsequent work will analyze petrographically the samples collected from the mineralized horizons of the mine and from adjacent deposits and wall rock carbonates. This work, through a better understanding of the depositional environment and mechanisms of formation will help the Peruvians in exploration and extension of ore bodies essential for their economy. It will also help the U.S. in studies of other rythmite-type deposits such as Mississippi Valley Zn-Pb and Pb-Zn-Ag-Ba deposits just below the sea water-sediment interface.
