Preliminary results of paleoseismic investigations of Quaternary faults on eastern Yucca Mountain, Nye County, Nevada
- Geological Survey, Denver, CO (United States)
- Geomatrix Consultants, San Francisco, CA (United States)
Site characterization of the potential nuclear waste repository at Yucca Mountain, Nevada, requires detailed knowledge of the displacement histories of nearby Quaternary faults. Ongoing paleoseismic studies provide data on the amount and rates of Quaternary activity on the Paintbrush Canyon, Bow Ridge, and Stagecoach Road faults along the eastern margin of the mountain over varying time spans of 0-700 ka to perhaps 0-30 ka, depending on the site. Preliminary stratigraphic interpretations of deposits and deformation at many logged trenches and natural exposures indicate that each of these faults have experienced from 3 to 8 surface-rupturing earthquakes associated with variable dip-slip displacements per event ranging from 5 to 115 cm, and commonly in the range of 20 to 85 cm. Cumulative dip-slip offsets of units with broadly assigned ages of 100-200 ka are typically less than 200 cm, although accounting for the effects of possible left normal-oblique slip could increase these displacements by factors of 1.1 to 1.7. Current age constraints indicate recurrence intervals of 10{sup 4} to 10{sup 5} years (commonly between 30 and 80 k.y.) and slip rates of 0.001 to 0.08 mm/yr (typically 0.01-0.02 mm/yr). Based on available timing data, the ages of the most recent ruptures among the faults; they appear younger on the Stagecoach Road Fault ({approximately} 5.20 ka) relative to the southern Paintbrush Canyon and Bow Ridge faults ({approximately} 30-100 ka).
- Research Organization:
- American Society of Civil Engineers (ASCE), New York, NY (United States); American Nuclear Society (ANS), La Grange Park, IL (United States)
- OSTI ID:
- 60970
- Report Number(s):
- CONF-940553-Vol.4; TRN: 94:010821-0076
- Resource Relation:
- Conference: International high-level radioactive waste management conference, Las Vegas, NV (United States), 22-26 May 1994; Other Information: PBD: 1994; Related Information: Is Part Of High Level Radioactive Waste Management: Proceedings of the fifth annual international conference. Volume 4; PB: 1048 p.
- Country of Publication:
- United States
- Language:
- English
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Paleoseismic investigations of Stagecoach Road fault, southeastern Yucca Mountain, Nye County, Nevada
Geologyy of the Yucca Mountain Site Area, Southwestern Nevada, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste (Volume 1)