Geology and geochemistry of the Deer Trail Pb-Zn-Ag-Cu manto deposits, Marysvale District, west-central Utah

Strata-bound sulphide replacement bodies in the Deer Trail mine are sinuous pipes in carbonate beds, approximately localized by an anticlinal axis, and radiate from a fault across the lower part of the Permian Toroweap formation. Indistinct sericitic envelopes provide a K/Ar age of 14 m.y., correlative with barren, altered volcanic rocks above a hypothesized intrusion, 1 km to the west. Lead and sulphur isotope data imply an igneous source. Inclusion data and deuterium and oxygen isotopes imply a magmatic fluid progressively diluted with meteoric waters. The deposits are the outer zone of a volcanic hydrothermal system. -G.J.N.