Geologic units in Norton county, Kansas

Loess (Holocene to Pleistocene) at surface, covers 62 % of this area

eolian silts

Ogallala Formation (Miocene) at surface, covers 20 % 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

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

unconsolidated sand, silt, clay, and gravel

Niobrara Chalk (Late Cretaceous) at surface, covers 3 % of this area

Interbedded, soft, light-gray calcareous shale and chalk

Ogallala Group or Formation (Miocene) at surface, covers 0.2 % of this area

Silt, sand, sandstone, gravel and conglomerate. Predominantly interfingered fine- to coarse grained, poorly sorted, arkosic, fluvial deposits of light-gray, light-olive-gray, and grayish-green calcareous silt and sand, and locally poorly consolidated conglomerate, sandstone, and siltstone.

Niobrara Formation (Late Cretaceous) at surface, covers < 0.1 % of this area

Argillaceous chalk, limestone and shale. Chalk is medium gray to white, interbedded with thin layers of chalky shale; contains many fossil clams, oysters, and formanifera. Limestone is light gray to medium gray and yellowish gray, interbedded with medium-gray chalky shale; also contains fossil clams, oysters, and formanifera. Bedding plans commonly marked by thin layers of gypsum and locally a thin bed of red flint occurs at top of unit. Approx. max thickness 570 ft.