Cenozoic volcanism and tectonics in the Queen Valley area, Esmeralda County, western Nevada

The Queen Valley pull-apart basin is located at the northern extent of the White Mountains in western Nevada. The basin is bounded to the south by the NE-trending Queen Valley fault zone and to the north by the E-W-trending Coaldale fault zone. The curvilinear trace of the Queen Valley normal fault extends -16 km northeast from the northern termination of the Owens Valley-White Mountain fault zone to the western Coaldale fault system. Using new (U-Th)/He and (super 40) Ar/ (super 39) Ar geochronology, fault kinematic data, and detailed geologic mapping (1:10,000), this study documents a three-stage late Tertiary tectonic evolution of the eastern Queen Valley area and defines the role of the Queen Valley fault system as an integral part of the right-lateral transtensional Walker Lane belt. The Queen Valley area was affected by an ignimbrite flare-up in Utah, Nevada, and California, as recorded by late Oligocene rhyolites (ca. 26 Ma). The eruption of these widespread ash flows was accompanied locally by extension, creating a series of ENE-trending half grabens. The faults are sealed by Miocene andesite (ca. 12 Ma), constraining the timing of extension to late Oligocene or early Miocene. Mid-Miocene Basin and Range extension produced E-dipping normal fault systems in the Yerington area to the north and W-dipping normal faults in the White Mountains to the south. Displacement between these fault systems with opposite polarity was accommodated by a series of right-lateral faults in the Queen Valley area. A change in extension direction from E-W extension to NW-SE during the Pliocene resulted in a transition to transcurrent and transtensional structures in the central Walker Lane belt. The beginning of transtension on the east side of the White Mountains was marked by the opening of the Fish Lake Valley pull-apart basin at ca. 6 Ma, as constrained by Upper Miocene volcanic units. Similarly, the Queen Valley pull-apart basin was a product of the reactivation of the White Mountain-Owens Valley fault zone as a right-lateral fault ca. 3 Ma, based on thermochronological data and offset Pliocene basaltic andesite (ca. 3.1 Ma) along the Queen Valley fault.