W. J. Carr, 1990. "Chapter 13: Styles of extension in the Nevada Test Site region, southern Walker Lane Belt; An integration of volcano-tectonic and detachment fault models", Basin and Range Extensional Tectonics Near the Latitude of Las Vegas, Nevada, Brian P. Wernicke
Download citation file:
Detailed geological information, supported by geophysical data and drill holes, indicates that several deformational styles characterize the Walker Lane Belt of the south-central Great Basin and Nevada Test Site region.
The region is split by a north-trending major volcano-tectonic rift that includes several large calderas and is filled with more than 4 km of Miocene volcanic rocks. The rift lies in a large right-step in the Walker Lane Belt and separates areas to the west containing recognized detachment-style faults and metamorphic rocks from adjoining terrain on the east that contains no recognized major detachment faults or exposures of metamorphosed rocks.
The volcano-tectonic trough was most active from about 16 to 10 Ma. The style and timing of Cenozoic faulting is different east and west of the rift, and well-dated volcanic sequences show that the principal faulting events occurred at different times and rates within adjacent structural domains. This variability suggests that no single tectonic process produced the Cenozoic structure of the region. Normal faulting east of the rift may have been controlled in part by extension accommodated by Mesozoic thrust faults.
It is proposed that the volcanic rift represents a pull-apart at a right-step in the Walker Lane Belt and that the rift was the headwall or breakaway zone for detachment faulting to the west. In this model, extensional faults of Miocene age within and immediately east of the rift are largely gravitational responses to magmatism, rifting, and volcano-tectonic collapse.