Cobblestone Canyon, Santa Catalina Mountains, Tucson, AZ | A Pleistocene debris flow levee constructed from large granitic and gneissic boulders extends south towards the Tucson Valley from the mouth of Cobblestone Canyon. Numerous sets of high-standing paleo debris flow snouts and levees are preserved at canyon mouths across the mountainfront. Modern debris flows occur along incised, bedrock-lined channels below.
For more on the Pleistocene debris-flows in the Santa Catalina Mountains, Youberg, A. and others, 2008, Geologic Mapping of Debris-flow deposits in the Santa Catalina Mountains, Pima County, Arizona: Arizona Geological Survey Digital Map - Debris Flow Map 01 (DM-DF-01), map scale 1:6,000. https://library.azgs.arizona.edu/item/AGDM-1552427092170-89
Photographer: Joseph Cook
Photo Date: January 2008