Strike-slip faulting along the Wassuk Range of the northern Walker Lane, Nevada

Shaopeng Dong, Gulsen Ucarkus, Steven G. Wesnousky, Jillian Maloney, Graham Kent, Neal Driscoll, Robert Baskin
2014 Geosphere  
A strike-slip fault is present outboard and subparallel to the Wassuk Range front within the central Walker Lane (Nevada, USA). Recessional shorelines of pluvial Lake Lahontan that reached its highstand ca. 15,475 ± 720 cal. yr B.P. are displaced ~14 m and yield a right-lateral slip-rate estimate approaching 1 mm/yr. The strike-slip fault trace projects southeastward toward the eastern margin of Walker Lake, which is ~15 km to the southeast. The trace is obscured in this region by recessional
more » ... on by recessional shorelines features that record the historical dessication of the lake caused by upstream water diversion and consumption. High-resolution seismic CHIRP (compressed high intensity radar pulse) profi les acquired in Walker Lake reveal ~20 k.y. of stratigraphy that is tilted westward ~20-30 m to the Wassuk Range front, consistent with ~1.0-1.5 mm/yr (20-30 m/20 k.y.) of vertical displacement on the main rangebounding normal fault. Direct evidence of the northwest-trending right-lateral strikeslip fault is not observed, although a set of folds and faults trending N35°E, conjugate to the trend of the strike-slip fault observed to the north, is superimposed on the west-dipping strata. The pattern and trend of folding and faulting beneath the lake are not simply explained; they may record development of Riedel shears in a zone of northwest-directed strike slip. Regardless of their genesis, the faults and folds appear to have been inactive during the past ~10.5 k.y. These observa-tions begin to reconcile what was a mismatch between geodetically predicted deformation rates and geological fault slip rate studies along the Wassuk Range front, and provide another example of strain partitioning between predominantly normal and strikeslip faults that occurs in regions of oblique extension such as the Walker Lane.
doi:10.1130/ges00912.1 fatcat:gkbgiv3mrjb7tf5a3umfa7s3qu