Geologic units in Ellis county, Kansas

Loess (Holocene to Pleistocene) at surface, covers 47 % of this area

eolian silts

Niobrara Chalk (Late Cretaceous) at surface, covers 17 % of this area

Interbedded, soft, light-gray calcareous shale and chalk

Alluvium (Holocene to Pleistocene) at surface, covers 14 % of this area

unconsolidated sand, silt, clay, and gravel

Carlile Shale (Late Cretaceous) at surface, covers 14 % 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 5 % 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

Greenhorn Limestone and Graneros Shale (Late Cretaceous) at surface, covers 2 % 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.

Alluvium (Pleistocene) at surface, covers 1 % of this area

unconsolidated sand, silt, clay, and gravel