The longer-term context of the Nevada seismic belt: Patterns of Holocene-latest Pleistocene faulting in central Nevada
- Arizona Geological Survey, Tucson, AZ (United States)
- Geoengineers, Portland, OR (United States)
- Geological Survey, Menlo Park, CA (United States)
Four large (M[approximately]7+) earthquakes occurred in a nearly continuous, N-S belt in west-central Nevada between 1915 and 1954. The number of large earthquakes and the striking pattern of surface ruptures suggest that these earthquakes represent a burst of faulting that has implications for the nature of fault behavior in the Great Basin. The authors conducted geomorphic studies to estimate ages of Holocene-latest Pleistocene paleoseismic events across a broad portion of central Nevada ([approximately]42,000 km[sup 2]) to assess longer-term (10[sup 4]-yr) temporal and spatial patterns of faulting. Diffusion-based fault-scarp modeling, calibrated using pluvial shoreline scarps from this region, provided age estimates for paleoseismic events with estimated uncertainties of [+-]30%. Age estimates for faulted and unfaulted alluvial surfaces derived from soil-profile development, tephra, and dated organic material supplemented scarp age estimates. The age estimates for Holocene-latest Pleistocene paleoseismic events in central Nevada provide a chronology that is sufficient to outline the general rates and patterns of faulting. Recurrence intervals of 10,000+ years characterize most faults in this region; a few of the most active fault zones have recurrence intervals as short as several thousand years. Faulting during this century clearly represents a temporal cluster of activity, because the historical rate of large-earthquake occurrence is about 10 times the longer-term average and central Nevada probably experienced only one large earthquake in the previous 2,000 years. Temporal and spatial clusters of paleoseismic activity apparently have occurred over intervals of several thousand years in portions of central Nevada. Mean age estimates for paleoseismic events suggest the possibility of short-term (<500-yr) temporal clusters of faulting across this region during the middle and late Holocene.
- OSTI ID:
- 5128658
- Report Number(s):
- CONF-9305259-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
Similar Records
Paleoseismology of latest Pleistocene and Holocene fault activity in central Oregon
Paleoseismologic studies of the Pajarito fault system, western margin of the Rio Grande rift near Los Alamos, NM
Related Subjects
GEOLOGIC FAULTS
AGE ESTIMATION
DISPLACEMENT RATES
SEISMICITY
NEVADA
EARTHQUAKES
GEOLOGIC HISTORY
GEOMORPHOLOGY
GREAT BASIN
QUATERNARY PERIOD
CENOZOIC ERA
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
NORTH AMERICA
SEISMIC EVENTS
USA
580000* - Geosciences