|Name||Hell Creek Formation|
|Geologic age||Upper Cretaceous|
Sedimentary > Clastic > Siltstone (Bed)poorly consolidated
Sedimentary > Clastic > Sandstone (Bed)poorly consolidated
Sedimentary > Clastic > Mudstone > Claystone (Bed)poorly consolidated
Sedimentary > Clastic > Mudstone > Claystone > Bentonite (Bed)ND003 - beds tend to be lignitic or bentonitic and typically poorly consolidated.
Sedimentary > Coal > Lignite (Bed)ND003 - beds tend to be lignitic or bentonitic and typically poorly consolidated.
|Comments||Map unit descriptions mix unconsolidated and sedimentary terms; using sedimentary terms with poorly consolidated according to other sources.|
North Dakota Geological Survey, 2001, Geologic Bedrock Map of North Dakota based on Bluemle, John P., 1983, Geologic and Topographic Bedrock Map of North Dakota, NDGS Miscellaneous Map 25, 1:670,000 scale.
USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/
|Counties||Bottineau - Bowman - Burleigh - Emmons - Grant - Kidder - Logan - McHenry - McIntosh - McLean - Morton - Pierce - Renville - Rolette - Sheridan - Sioux - Slope - Ward - Wells|