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Geophysical constraints on the location and geometry of the Las Vegas Shear Zone, Nevada

Tectonics

By:
, , , , and
DOI: 10.1029/1999TC001159

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Abstract

We model the basin configuration beneath Las Vegas Valley, Nevada, on the basis of gravity, drillhole, and seismic reflection data. We locate and characterize the various strands of the Las Vegas Valley Shear Zone (LVVSZ) by variations in basin thickness beneath the valley. The pre-Tertiary bedrock surface is complex, with subbasins buried beneath the flat alluvial surface of the valley. We suggest that these basins are formed from transtensional strain. Subbasins elongated N70??W and N50??W are interpreted as strike-slip basins. The deepest subbasin is 5 km west of Frenchman Mountain and strikes N40??E. This basin probably formed by combined movement on nonparallel strands of the LVVZ and an earlier episode of normal faulting. The basin thickness map constrains the minimum depth of the inferred detachment fault beneath Las Vegas Valley to at least 4 km. Seismic reflection data do not image a detachment fault in the upper 10 km beneath Las Vegas Valley. Our results also illustrate the utility of gravity in determining basinal structures and providing a three-dimensional perspective in areas with limited seismic reflection control.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Geophysical constraints on the location and geometry of the Las Vegas Shear Zone, Nevada
Series title:
Tectonics
DOI:
10.1029/1999TC001159
Volume
20
Issue:
2
Year Published:
2001
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Tectonics
First page:
189
Last page:
209
Number of Pages:
21