The La Plata Mountains formed about 65 Ma when magmas were emplaced into older sedimentary rocks creating a dome-shaped mountain range. Some of the intrusive rocks are spatially related to copper mineralization. The greatest concentration of copper-bearing ore deposits in the La Plata Mountains occur within and around the Allard Stock. The Allard stock, one of two major syenite stocks, is cross cut with numerous veins and zones of chalcopyrite...