Geologic units in Ellsworth county, Kansas

Dakota Formation (Early Cretaceous) at surface, covers 40 % of this area

White, gray, red, brown and tan kaolinitic claystone, mudstone, shale and siltstone interbedded with grayish to yellowish brown thick lenticular sandstone beds. It also contains lignite and sandstone is commonly well cemented with iron oxide and calcite.

Alluvium (Pleistocene) at surface, covers 17 % of this area

unconsolidated sand, silt, clay, and gravel

Greenhorn Limestone and Graneros Shale (Late Cretaceous) at surface, covers 16 % of this area

Greenhorn FM- thin bedded gray, chalky limestone and calcareous shale. Graneros Shale- fissile, noncalcareous, gray shale locally contains sandstone and siltstone beds.

Loess (Holocene to Pleistocene) at surface, covers 15 % of this area

eolian silts

Alluvium (Holocene to Pleistocene) at surface, covers 5 % of this area

unconsolidated sand, silt, clay, and gravel

Kiowa Shale and Cheyenne Sandstone (Early Cretaceous) at surface, covers 4 % of this area

Kiowa Shale or FM- light -gray to black illitic shale with thin coquinoidal limestone beds at the base; sandstone lenses common. Cheyenne Sandstone- massive to crossbedded, light-gray to buff fine-grained sandstone with lenses of gray sandy shale and conglomerate.

Carlile Shale (Late Cretaceous) at surface, covers 2 % of this area

Chalky shale with bentonite and thick chalk beds, dark gray fissile shale containing septarian concretions, and fine-grained sandstone.

Ogallala Formation (Miocene) at surface, covers 0.3 % of this area

massive to cross-bedded, generally arkosic sand, silt and gravel, locally cemented with calcium carbonate; also contains limestone, volcanic ash, diatomaceous marl, opaline sandstone and bentonitic clay