Kansas has been divided into eleven different
physiographic regions.
Ozark plateau Mississippian limestones and cherts of the Ozark Plateau are exposed in extreme southeastern Kansas in
Cherokee County. This area was part of the
Tri-state district of the nineteenth and twentieth centuries.
Galena was a center of
lead and
zinc mining in the area.
Cherokee lowlands The Cherokee lowlands is a region of southeast Kansas immediately north and west of the Ozark plateau in Cherokee,
Labette,
Crawford and
Bourbon Counties. The lowlands are developed on areas of gently rolling hills developed on the shale and sandstone of the Cherokee Group of the Pennsylvanian age. The Cherokee Group is noted for rich deposits of coal in Kansas and across the midwestern United States.
Osage Cuestas The Osage cuesta region underlies twenty counties in southeastern Kansas. The
cuestas are a region of east to southeast facing
escarpments ( high) formed on resistant limestone units which
dip gently to the west and northwest. Areas between escarpments are underlain by shales. The cuesta region contains coal, black shale and some
oil shales.
Lamproite sills occur within the cuesta units of
Woodson and
Wilson counties. These unusual
igneous rocks were intruded in the Cretaceous Period.
Chautauqua Hills The Chautauqua Hills represent a narrow region in southeast Kansas of sandstone-capped ridges and rolling hills. The Pennsylvanian age sandstones were deposited in a large river valley. The sandstones are the Tonganoxie Sandstone Member of the Stranger Formation and the Ireland Sandstone Member of the Lawrence Formation. The hills occur in the western portions of
Montgomery,
Wilson and
Woodson counties and the eastern edges of
Chautauqua,
Elk and
Greenwood counties. The sandstones continue into northern Oklahoma.
Flint Hills The Flint Hills developed on the north–south exposure of Permian
cherty limestones. The region extends from
Marshall County in the north, to
Cowley County and on into northern Oklahoma where they are known as the
Osage Hills. The Permian limestones contain abundant
weathering resistant chert (or flint) and the residuum and soils of the hilltops and the streambeds of the region contain abundant cherty gravels. Surface exposures of the rare igneous
kimberlites occur in
Riley and
Marshall counties. The kimberlite
diatremes are of Cretaceous age. No diamonds have been found in the Kansas kimberlite occurrences.
Garnet crystals from the kimberlites have been reported in local stream gravels.
Red Hills The Red Hills cover a section of southern Kansas in
Clark,
Comanche, and
Barber counties along the Oklahoma border. The Red Hills are named for their color derived from the Permian
red beds which outcrop and underlie the region. The red color is produced by abundant
iron oxides in the weathering sediments. The region is underlain by red shales, siltstones, and sandstones along with interbedded
dolomites and
gypsum evaporite layers. Massive gypsum deposits are mined near
Sun City in northwestern Barber County. The Gyp Hills near
Medicine Lodge were named for the gypsum of the Blaine Formation. The soluble gypsum,
anhydrite and dolomite produce many
caves in the area. The
Big Basin of
Clark County is a diameter, deep, dissolution collapse feature that formed by the dissolution of salt beds in the subsurface.
Smoky Hills The Smoky Hills constitute a large area of north central Kansas. The area is underlain by Cretaceous sediments. Rocks outcropping in the area include the sandstones of the
Dakota Formation, the
Greenhorn Limestone, and the thick
Niobrara Chalk. Stratigraphically the Dakota is overlain by the Greenhorn and that by the Niobrara. The Dakota outcrops in the eastern portion of the region as gently westward dipping resistant ridges. Although the sandstones are the most resistant and therefore most prominent the Dakota includes shales and clays. The formation contains abundant brown iron oxides and many
concretions are found in the area. In the western portions of the area, the bedrock is
fossiliferous
chalk of the Niobrara Formation which includes the
Smoky Hill Chalk member noted for abundant fish and
marine reptile fossils.
High Plains The western third of Kansas is in the High Plains area. The highest point in Kansas,
Mount Sunflower (), is located in the High Plains physiographic region. The
tectonic uplift of the
Rocky Mountains during the
Cenozoic resulted in erosion and deposition of vast quantities of non-marine sediments eastward across the High Plains. The
Ogallala Formation consists of a large wedge of unconsolidated sands and silts that is a significant
aquifer under the plains. The Ogallala contains a sandstone layer cemented with
opal. In the southwest corner of the state in
Morton County rocks of
Jurassic age outcrop along the
Cimarron River.
Loess deposits cover much of the High Plains in north and northwest Kansas.
Glaciated Region The northeast corner of the state, north of the
Kansas River and east of the
Big Blue River, is covered by
glacial debris deposited during the Pre-Illinoian glaciations which occurred 600,000 years ago in the
Pleistocene. The Pennsylvanian and Permian bedrock is buried under thick deposits of glacial debris, largely loess. A variety of
glacial erratics were left by the melting glaciers. Many of these are of
Sioux Quartzite carried south from the
Sioux Falls, South Dakota area.
Wellington-McPherson Lowlands The Wellington-McPherson Lowlands of south-central Kansas in
Sumner,
Sedgwick,
Harvey and
McPherson counties is underlain by fluvial sediments deposited in the ancestral
Arkansas River valley during the Pleistocene Epoch one to two million years ago. The sediments consist largely of sands, silts, and gravel. These include the
Equus Beds Aquifer sediments, named for the Pleistocene
modern horse fossils they contain. Also under this area is the Permian
Hutchinson salt bed which reaches a thickness of . The area also contains inactive sand dunes.
Arkansas River Lowlands The Arkansas River Lowlands follows the course of the
Arkansas River through southwest and south-central Kansas. The broad floodplain contains large quantities of sand and silt carried from the Rocky Mountains by the river. A significant area of sand dunes occur on the south side of the plain formed by the prevailing winds from the glaciers to the north during the Pleistocene. ==Subsurface geology==