Geologic Map of the Clifton Quadrangle, Mesa County, Colorado

1:24,000-scale geologic mapping in the Clifton 7.5' quadrangle, in
support of the USGS Colorado River/I-70 Corridor Cooperative Geologic
Mapping Project, provides interpretations of the Quaternary
stratigraphy and geologic hazards in this area of the Grand Valley.
The Clifton 1:24,000 quadrangle is in Mesa County in western
Colorado. Because the map area is dominated by various surficial
deposits, the map depicts 16 different Quaternary units. Five
prominent river terraces are present in the quadrangle containing
gravels deposited by the Colorado River. The map area contains a
large landslide deposit on the southern slopes of Mount Garfield.
The landslide developed in the Mancos Shale and contains large blocks
of the overlying Mesaverde Group. In addition, the landslide is a
source of debris flows that have closed I-70 in the past. The major
bedrock unit in the quadrangle is the Mancos Shale of Upper
Cretaceous age.
The map is accompanied by text containing unit descriptions, and
sections on geologic hazards (including landslides, piping, gullying,
expansive soils, and flooding), and economic geology (including sand
and gravel). A table indicates what map units are susceptible to a
given hazard. Approximately 20 references are cited at the end of the
report.