- Usage in publication:
-
- Lehman Ridge Gravel*
- Modifications:
-
- Named
- Dominant lithology:
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- Gravel
- AAPG geologic province:
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- Denver basin
Summary:
Named after Lehman Ridge, its type locality, about 2,500 ft east of the cadet academic area, U.S. Air Force Academy site, El Paso Co, CO in the Denver basin. Crops out on ridge north of Jack valley and on highest pediment remnants north of Pine valley. Is composed of reddish-brown fragments of Pikes Peak Granite ranging in size from silt to boulders 20 ft in diameter. Pebbles of quartz and feldspar 1/4 to 1 inch diameter make up bulk of gravel. Boulders are more numerous and larger near the mountains. Is poorly sorted and bedded. Ranges from 25 to 50 ft thick. Correlated with Rocky Flats Alluvium of the Denver area. Overlies Dawson Arkose. Is older than Douglass Mesa Gravel (new). Of Pleistocene age, probably Nebraskan or Aftonian. Geologic map.
Source: GNU records (USGS DDS-6; Denver GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).