Eric H. Christiansen Donald Edward Lee 1983 The Snake Creek-Williams Canyon pluton of the southern Snake Range crops out over an area of about 30 km 2, about 60 km southeast of Ely, Nev. This Jurassic intrusion displays large and systematic chemical and mineralogical zonation over a horizontal distance of 5 km. Major-element variations compare closely with Dalyls average andesite-dacite-rhyolite over an SiO 2 range of 63 to 76 percent. For various reasons it was originally thought that assimilation played a dominant role in development of the Snake Creek-Williams Canyon pluton. However, based on modeling of more recently obtained trace element and isotopic data, we have concluded that the zonation is the result of in-situ fractional crystallization, with little assimilation at the level of crystallization. This report summarizes data available for each of the mineral species present in the zoned intrusion. Special attention has been paid to trends that might relate to the variation in the chemical petrology of the pluton. application/pdf 10.3133/ofr83337 en U.S. Geological Survey, The mineralogy of the Snake Creek-Williams Canyon pluton, southern Snake Range, Nevada reports