Geologic units in Seward county, Kansas

Loess (Holocene to Pleistocene) at surface, covers 44 % of this area

eolian silts

Dune Sand (Holocene to Pleistocene) at surface, covers 40 % of this area

unconsolidated dune sand

Alluvium (Pleistocene) at surface, covers 11 % of this area

unconsolidated sand, silt, clay, and gravel

Alluvium (Holocene to Pleistocene) at surface, covers 4 % of this area

unconsolidated sand, silt, clay, and gravel

Ogallala Formation (Miocene) at surface, covers 0.7 % 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

Dune Sand (Pleistocene) at surface, covers < 0.1 % of this area

CIMARRON- Fine- to medium-grained sand 0 to 40 feet thick. TEXAS- Fine to coarse windblown sand. Maximum thickness about 30 feet. BEAVER- Fine to coarse, round to sub-round, windblown sand consisting mostly of quartz grains. 0-50 feet thick.

Ogallala Formation (Pliocene) at surface, covers < 0.1 % of this area

CIMARRON- Generally semiconsolidated clay, silt, sand, gravel, and caliche 0 to 400 feet thick. BEAVER- Interbedded sand, siltstone, clay, gravel lenses, and thin limestone. Caliche common near surface but occurrence is not limited to the surface. Caliche accounts for most of the white color in the Ogallala. Other colors generally light tan or buff but locally may be pastel shades of almost any color. The Laverne and Rexroad Formations of Pliocene age and the Meade Group and Odee (of local usage) and other formations of Pleistocene age occur locally and are included with the Ogallala Formation, 0-700 feet thick. WOODWARD- Gravel, sand, silt, clay, caliche, and limestone, locally cemented with calcium carbonate. Generally light-tan to gray to white. Thickness ranges up to 400 feet and probably averages 150 feet. CLINTON- Gray to light-brown, fine- to medium-grained sand with some, clay, silt, gravel, volcanic ash, and caliche beds; locally cemented by calcium carbonate. Thickness ranges from 0 to about 320 feet. The formation thins eastward.