Possible young faulting in the Piedmont of North-Central Colorado

We interpret several linear topographic scarps in both alluvium and bedrock in the piedmont of north-central Colorado between Denver and Wyoming to be fault scarps. The scarps, ranging from tens of feet to about 150 ft in height, bound trough-like (graben and half-graben) forms. These features coincide in part with the floodplains of the South Platte River and Lone Tree, St. Vrain, and Boulder Creeks. Details of their topographic forms as well as relations of the Holocene and Pleistocene gravels underlying the floodplains suggest to us that the forms resulted from Quaternary tectonism.