Structural geology of the French Peak accommodation zone, Nevada Test Site, southwestern Nevada
The French Peak accommodation zone (FPAZ) forms an east-trending bedrock structural high in the Nevada Test Site region of southwestern Nevada that formed during Cenozoic Basin and Range extension. The zone separates areas of opposing directions of tilt and downthrow on faults in the Yucca Flat and Frenchman Flat areas. Paleomagnetic data show that rocks within the accommodation zone adjacent to Yucca Flat were not strongly affected by vertical-axis rotation and thus that the transverse strikes of fault and strata formed near their present orientation. Both normal- and oblique strike-slip faulting in the FPAZ largely occurred under a normal-fault stress regime, with least principal stress oriented west-northwest. The normal and sinistral faults in the Puddle Peka segment transfers extension between the Plutonium Valley normal fault zone and the Cane Spring sinistral fault. Recognition of sinistral shear across the Puddle Peak segment allows the Frenchman Flat basin to be interpreted as an asymmetric pull-apart basin developed between the FPAZ and a zone of east-northeast-striking faults to the south that include the Rock Valley fault. The FPAZ has the potential to influence ground-water flow in the region in several ways. Fracture density and thus probably fracture conductivity is high within the FPAZ due to the abundant fault splays present. Moreover,, fractures oriented transversely to the general southward flow of ground water through Yucca Flat area are significant and have potential to laterally divert ground water. Finally, the FPAZ forms a faulted structural high whose northern and southern flanks may permit intermixing of ground waters from different aquifer levels, namely the lower carbonate, welded tuff, and alluvial aquifers. 42 refs.
- Research Organization:
- Geological Survey, Denver, CO (United States)
- Sponsoring Organization:
- Geological Survey, Reston, VA (United States)
- OSTI ID:
- 573191
- Report Number(s):
- USGS/OFR--97-56; ON: DE98003405
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sub-crop geologic map of pre-Tertiary rocks in the Yucca Flat and northern Frenchman Flat areas, Nevada Test Site, southern Nevada
Operation TUMBLER-SNAPPER, Nevada Proving Ground. Project 1. 8. A geological survey of the Atomic Energy Commission Area, Nye County, Nevada. Report for April-June 1952
Paleomagnetic evaluation of the Yucca-Frenchman Flexure, southern Nevada
Technical Report
·
Thu Oct 02 00:00:00 EDT 1997
·
OSTI ID:1061
Operation TUMBLER-SNAPPER, Nevada Proving Ground. Project 1. 8. A geological survey of the Atomic Energy Commission Area, Nye County, Nevada. Report for April-June 1952
Technical Report
·
Sat Feb 28 23:00:00 EST 1953
·
OSTI ID:6458587
Paleomagnetic evaluation of the Yucca-Frenchman Flexure, southern Nevada
Conference
·
Sat Dec 31 23:00:00 EST 1988
·
OSTI ID:5978663