Chronology of intrusion, volcanism, and ore deposition at Bingham, Utah

Potassium-argon dates for major igneous rock types in the Bingham mining district, Utah, range from 39 to 32 m.y. and suggest that:(1) Plutonism, volcanism, and hydrothermal activity were sequential stages in a magmatic history of about 7 m.y. duration.(2) Latitic volcanic rocks, in part, postdate emplacement of the Last Chance and Bingham stocks.(3) Sulfide mineralization and hydrothermal alteration followed emplacement of the monzonitic stocks and extrusion of at least the earliest units in the volcanic sequence; the time interval between intrusion and alteration was probably less than 1 m.y.(4) The rhyolites of Shaggy Peak, which may represent terminal differentiation products in a comagmatic series, are the youngest igneous rocks in the area.