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Coleharbor Formation- Offshore Sediment- Proglacial Lake Sediment

Laminated silt and clay of glacier-dammed lakes; as thick as 60 meters (200 feet). Flat-bedded sediment of low-lying plains
State North Dakota
Name Coleharbor Formation- Offshore Sediment- Proglacial Lake Sediment
Geologic age Phanerozoic | Cenozoic | Quaternary | Pleistocene Holocene
Comments Coleharbor Formation- Sandy, silty clay with pebbles of limestone, dolomite, granite, gneiss, and basalt; nonorganic, bedded clay, silt, sand, and gravel; as thick as 200 meters (600 feet).
Primary rock type silt
Secondary rock type clay or mud
Other rock types
Lithologic constituents
Major
Unconsolidated > Fine-detrital > Silt (Glacial)
Unconsolidated > Fine-detrital > Clay (Glacial)
Map references
Clayton, Lee, 1980, Geologic Map of North Dakota: U. S. Geological Survey, Scale 1:500K.
Unit references
Clayton, Lee, 1980, Geologic Map of North Dakota: U. S. Geological Survey, Scale 1:500K.
Counties Benson - Bottineau - Cass - Dickey - Emmons - Grand Forks - Logan - McHenry - Mountrail - Pembina - Pierce - Ramsey - Renville - Richland - Rolette - Sargent - Sioux - Towner - Traill - Walsh - Ward