East Kamas fault (Class A) No. 2391
Last Review Date: 1999-10-01
Compiled in cooperation with the Utah Geological Survey
citation for this record: Black, B.D., and Hecker, S., compilers, 1999, Fault number 2391, East Kamas fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, https://earthquakes.usgs.gov/hazards/qfaults, accessed 09/26/2023 07:59 PM.
Poorly understood Quaternary(?) faults bounding the eastern side of Kamas Valley appear to have been last active before 130-140 ka.
Fault ID: Refers to fault number 12-11 of Hecker (1993 #642).
|County(s) and State(s)||
SUMMIT COUNTY, UTAH
MIDDLE ROCKY MOUNTAINS
|Reliability of location||
Compiled at 1:250,000 scale.
Comments: Fault traces from mapping of Sullivan and others (1988 #4508).
Generally north-trending range-front normal faults along the eastern side of Kamas Valley on the western edge of the Uinta Mountains.
|Length (km)||15 km.|
|Sense of movement||Normal|
Range-front escarpment. Alluvial deposits that are estimated to be 130-140 ka (Sullivan and others, 1988 #4508) cross the inferred trace of the fault and appear to be unfaulted. Degraded scarps on old alluvial-fan remnants could be the result of faulting, but the presence of a parallel scarp (terrrace riser) cut by the Weber River suggests an erosional origin is more likely.
|Age of faulted surficial deposits||Quaternary(?); deposits that are estimated to be 130-140 ka (Sullivan and others, 1988 #4508) appear to be unfaulted.|
|Most recent prehistoric deformation||
undifferentiated Quaternary (<1.6 Ma)
Comments: Based on range-front morphology and soil development, Sullivan and others (1988 #4508) reported no evidence for late Quaternary faulting.
Less than 0.2 mm/yr
Comments: Unfaulted 130-140 ka deposits (Sullivan and others, 1988 #4508) indicate a low slip rate.
|Date and Compiler(s)||
Bill D. Black, Utah Geological Survey
Suzanne Hecker, U.S. Geological Survey
#642 Hecker, S., 1993, Quaternary tectonics of Utah with emphasis on earthquake-hazard characterization: Utah Geological Survey Bulletin 127, 157 p., 6 pls., scale 1:500,000.
#4508 Sullivan, J.T., Nelson, A.R., LaForge, R.C., Wood, C.K., and Hansen, R.A., 1988, Central Utah regional seismotectonic study for USBR dams in the Wasatch Mountains: Bureau of Reclamation Seismotectonic Report 88-5, 269 p.