By: L. A. Piety, L. W. Anderson, and D. A. Ostenaa
East Canyon Valley, a 25-km-long by 5-km-wide back-valley, is on the eastern flank of the Wasatch Range about 25 km northeast of Salt Lake City and the Wasatch Front. Previous geologic mapping and the geomorphic expression of this north-northeast-trending valley suggest that East Canyon valley is a middle to late Cenozoic half-graben bounded on the west by the East Canyon fault. The Main Canyon fault, previously referred to as the East of East Canyon or East Canyon â€“ East Side fault, is a down-to-the-west normal fault that partly coincides with the drainage divides that bound the east side of East Canyon valley. The Main Canyon fault cuts across existing topography, but has nearly continuous expression in the landscape for about 26 km. Previous interpretations have suggested that the Main Canyon fault is a minor structural feature, antithetic to the East Canyon fault.
This Utah Geological Survey Miscellaneous Publication, Late Quaternary Faulting in East Canyon Valley, Northern Utah, is the nineteenth report in the Paleoseismology of Utah series. This series makes the results of paleoseismic investigations in Utah available to geoscientists, engineers, planners, public officials, and the general public. These studies provide critical information regarding paleoearthquake parameters such as earthquake timing, recurrence, displacement, slip rate, fault geometry, and segmentation, which can be used to characterize potential seismic sources and evaluate the long-term seismic hazard of Utahâ€™s Quaternary faults. The purpose of this study was to evaluate the Quaternary activity of the two faults as part of a seismic safety assessment of East Canyon Dam.
Pages: 39 p. + 8 appendices
Location: Cache County, Morgan County, Rich County, Summit County, and Weber County