Abstract
The age of fault scarps in unconsolidated deposits is commonly estimated by several criteria such as the extent of dissection, amount of rounding of the crest of the scarp, and the slope of the face of the scarp. To provide a more quantitative basis for evaluating the ages of fault scarps in western Utah, we have measured numerous profiles across late Quaternary fault scarps and studied the relationship between scarp height, slope angle, and age. Well-defined curves delineated by the data suggest that for a given age, (1) the slope angle of the scarp is proportional to the logarithm of the scarp height and (2) the slope angle decreases with estimated age for scarps of a given height. Owing to the lack of well-determined ages for the scarps studied, age assignments are only approximate; the available information provides a means of ranking scarps according to relative geomorphic age within a general age framework for scarps between several thousand and several hundred thousand years old.
