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Arikaree Group

Consists mainly of gray, fine, loose to compact sand that has layers of hard, fine-grained dark-gray concretions which vary from few in to 15 in and often have tabular form. Includes a large amount of volcanic ash mixed in with the sand. Contains a number of channels filled with coarse conglomerate along ridge south of North Platte River. About 500 ft thick.
State Nebraska
Name Arikaree Group
Geologic age Phanerozoic | Cenozoic | Tertiary | Oligocene Miocene
Comments Includes in decending order: Monroe Creek and Sharps FMs.
Primary rock type sand
Secondary rock type volcanic ash
Other rock types conglomerate
Lithologic constituents
Major
Unconsolidated > Coarse-detrital > Sand (Bed)
Minor
Sedimentary > Clastic > Conglomerate (Bed)
Map references
Burchett, R. R., 1986, Geologic Bedrock Map of Nebraska: Nebraska Geological Survey. Scale 1:1 Million.
Unit references
Burchett, R. R., 1986, Geologic Bedrock Map of Nebraska: Nebraska Geological Survey. Scale 1:1 Million.
Darton, N. H., 1899, Preliminary report on the geology and water resources of Nebraska west of the one hundred and third meridian: U.S Geological Survey, 19th Annual Report, p. 721-785.
Counties Banner - Box Butte - Cherry - Dawes - Morrill - Scotts Bluff - Sheridan - Sioux