• journal_title：Bulletin of the Seismological Society of America
• Contributor：Ryan Gold ; Craig dePolo ; Richard Briggs ; Anthony Crone ; John Gosse
• Publisher：Seismological Society of America
• Date：2013-02-01
• Format：text/html
• Language：en
• Identifier：10.1785/0120120020
• journal_abbrev：Bulletin of the Seismological Society of America
• issn：0037-1106
• volume：103
• issue：1
• firstpage：542
• section：Articles

The extent to which faults exhibit temporally varying slip rates has important consequences for models of fault mechanics and probabilistic seismic hazard. Here, we explore the temporal behavior of the dextral‐slip Warm Springs Valley fault system, which is part of a network of closely spaced (10–20 km) faults in the northern Walker Lane (California–Nevada border). We develop a late Quaternary slip record for the fault using Quaternary mapping and high‐resolution topographic data from airborne Light Distance and Ranging (LiDAR). The faulted Fort Sage alluvial fan (40.06° N, 119.99° W) is dextrally displaced line-formula" id="inline-formula-1">line-graphic" alt="Graphic" src="542/embed/inline-graphic-1.gif" />, and we estimate the age of the alluvial fan to be line-formula" id="inline-formula-2">line-graphic" alt="Graphic" src="542/embed/inline-graphic-2.gif" /> to 55.7±9.2  ka, based on a terrestrial cosmogenic line-formula" id="inline-formula-3">line-graphic" alt="Graphic" src="542/embed/inline-graphic-3.gif" /> depth profile and line-formula" id="inline-formula-4">line-graphic" alt="Graphic" src="542/embed/inline-graphic-4.gif" /> analyses on basalt boulders, respectively. The displacement and age constraints for the fan yield a slip rate of line-formula" id="inline-formula-5">line-graphic" alt="Graphic" src="542/embed/inline-graphic-5.gif" /> to line-formula" id="inline-formula-6">line-graphic" alt="Graphic" src="542/embed/inline-graphic-6.gif" /> (2σ) along the northern Warm Springs Valley fault system for the past 41.4–55.7 ka. In contrast to this longer‐term slip rate, shorelines associated with the Sehoo highstand of Lake Lahontan (∼15.8  ka) adjacent to the Fort Sage fan are dextrally faulted at most 3 m, which limits a maximum post‐15.8 ka slip rate to 0.2  mm/yr. These relations indicate that the post‐Lahontan slip rate on the fault is only about one‐tenth the longer‐term (41–56 ka) average slip rate. This apparent slip‐rate variation may be related to co‐dependent interaction with the nearby Honey Lake fault system, which shows evidence of an accelerated period of mid‐Holocene earthquakes.