Geologic units in McPherson county, Kansas

Loess (Holocene to Pleistocene) at surface, covers 56 % of this area

eolian silts

Kiowa Shale and Cheyenne Sandstone (Early Cretaceous) at surface, covers 12 % 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.

Alluvium (Holocene to Pleistocene) at surface, covers 8 % of this area

unconsolidated sand, silt, clay, and gravel

Alluvium (Pleistocene) at surface, covers 6 % of this area

unconsolidated sand, silt, clay, and gravel

Sumner Group (Late Permian - Cimarronian) at surface, covers 6 % of this area

Ninnescah Shale (base N)- mostly red silty shale with some gray shale , argillaceous limestone and dolomite. Wellington FM with Carlton Limestone Member (base CR)-mostly gray and some red shale with minor limestone and dolomite, siltstone, gypsum and anhydrite

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

Nippewalla Group (Late Permian- Custerian to Cimarronian) at surface, covers 4 % of this area

Dog Creek FM- maroon silty shale, siltstone, fine-grained feldspathic sandstone. Blaine FM- (base B) gypsum beds seperated by dolomite and red shale. Flower Pot Shale -(base FL) red gypsiferous shale silty shale and minor sandstone and siltstone. Cedar Hills Sandstone- feldspathic sandstone, siltstone, and silty shale. Salt Plain FM- red flaky, silty shale and some siltstone with thick salt beds at base. Harper Sandstone with Kingman Sandstone member (base K)- red argillaceous siltstone and fine silty sandstone with a few beds of res shale and white sandstone. Stone Coral FM- dolomite, anhydrite, gypsum and salt.

Dakota Formation (Early Cretaceous) at surface, covers 2 % 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.

Dune Sand (Holocene to Pleistocene) at surface, covers 1 % of this area

unconsolidated dune sand