The geology of Kansas encompasses the geologic history and the presently exposed rock and

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

. Rock that crops out in the US state of

Kansas Kansas () is a U.S. state, state in the Midwestern United States, Midwestern United States. Its Capital city, capital is Topeka, Kansas, Topeka, and its largest city is Wichita, Kansas, Wichita. Kansas is a landlocked state bordered by Nebras ...

was formed during the

Phanerozoic eon The Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 538.8 million years to the present, and it began with the Cambrian Period, when anima ...

, which consists of three geologic eras: the

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ...

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

and

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

. Paleozoic rocks at the surface in Kansas are primarily from the Mississippian, Pennsylvanian, and

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

periods.

Paleozoic Era

The oldest rocks at the surface in Kansas are Mississippian rocks that consist of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a ...

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicat ...

s, and

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

s. The Mississippian consisted of an environment similar to present. Fast moving streams and rivers cut into the limestone bedrock, and in some places, create caverns and

sinkhole A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are locally also known as ''vrtače'' and shakeholes, and to openi ...

s.Buchanan, R., ''Kansas Geology: An Introduction to Landscapes, Rock, Minerals, and Fossils,'' University Press of Kansas, 1984, Ch 1, p. 10 ff Pennsylvanian rocks consist predominantly of alternating marine and non-marine shales and limestones with some sandstone,

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...

, chert, and conglomerate. The Pennsylvanian was a time that the region that is now eastern Kansas stayed nearly at sea level. Between the transgression and regression of the seas, swamps, and bogs formed, depositing dead vegetation and later, after burial under younger sediments, this dead vegetation formed into coal. Permian rocks predominantly consist of limestones, shales, and

evaporite An evaporite () is a water- soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean ...

s. The Permian in Kansas began as an environment consisting of warm, shallow seas. As the Permian progressed, the climate became very dry and the seas began to subside, creating bodies of water shut off from the open seas, in turn creating areas for the generation of dark shales and evaporite minerals such as

halite Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, p ...

and

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywa ...

as the waters evaporated. The end of the Permian marks the largest extinction period in Earth's history; over 90% of all life disappeared.

Mesozoic Era

Mesozoic rocks at the surface in Kansas consist predominantly of rocks from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

. A relatively small outcrop of

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

sediments are exposed in the southwest corner of the state. Cretaceous age rocks consist of

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. C ...

, shale, and sandstone. The Cretaceous in Kansas was an open ocean or sea environment dominated by microscopic marine plants and animals that floated or swam near the surface of this ancient water body. As these microscopic creatures died, they sank to the bottom, formed a soft, limy ooze, and would preserve any larger creatures that died and sank into it.

Cenozoic Era

Cenozoic rocks at the surface were formed during the

Paleogene The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning o ...

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

, and

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...

periods. Paleogene to Neogene rocks in Kansas consist of river silt, sand, freshwater limestones, and some

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer ...

derived from eruptions in the western United States. Near the beginning of the Paleogene, the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...

were formed, as were the streams and rivers heading eastward out from the mountains into Kansas. Over 60 million years of

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...

, the Rocky Mountains created a wedge of material extending to the

Flint Hills The Flint Hills, historically known as Bluestem Pastures or Blue Stem Hills, are a region in eastern Kansas and north-central Oklahoma named for the abundant residual flint eroded from the bedrock that lies near or at the surface. It consists of ...

of eastern Kansas. Quaternary rocks in Kansas consist of these:

glacial drift In geology, drift is a name for all sediment (clay, silt, sand, gravel, boulders) transported by a glacier and deposited directly by or from the ice, or by glacial meltwater. Drift is often subdivided into (unsorted and) unstratified drift (gla ...

; river silt, sand, and gravel;

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

sand; and wind blown silt. The Quaternary Period in western Kansas was very similar to the Neogene, continual erosion of the Rocky Mountains deposited additional sediments.

Physiographic regions

Kansas has been divided into eleven different

physiographic Physical geography (also known as physiography) is one of the three main branches of geography. Physical geography is the branch of natural science which deals with the processes and patterns in the natural environment such as the atmosphere ...

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 The Tri-State district was a historic lead-zinc mining district located in present-day southwest Missouri, southeast Kansas and northeast Oklahoma. The district produced lead and zinc for over 100 years. Production began in the 1850s and 1860s in ...

of the nineteenth and twentieth centuries.

Galena Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It cr ...

was a center of

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...

and

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the econom ...

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 hils developed on the shale and sandstone of the Cherokee Group of 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

cuesta A cuesta (from Spanish ''cuesta'' "slope") is a hill or ridge with a gentle slope on one side, and a steep slope on the other. In geology the term is more specifically applied to a ridge where a harder sedimentary rock overlies a softer laye ...

s are a region of east to southeast facing

escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...

s (50 to 200 feet 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 shale Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitut ...

Lamproite Lamproite is an ultrapotassic mantle-derived volcanic or subvolcanic rock. It has low CaO, Al2O3, Na2O, high K2O/Al2O3, a relatively high MgO content and extreme enrichment in incompatible elements. Lamproites are geographically widespread ...

sills occur within the cuesta units of Woodson and Wilson counties. These unusual

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma o ...

s 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 Ireland Sandstone Member of the Lawrence Formation. The hills occur in the western portions of Montgomery,

Wilson Wilson may refer to: People *Wilson (name) ** List of people with given name Wilson ** List of people with surname Wilson * Wilson (footballer, 1927–1998), Brazilian manager and defender * Wilson (footballer, born 1984), full name Wilson R ...

and Woodson counties and the eastern edges of

Chautauqua Chautauqua ( ) was an adult education and social movement in the United States, highly popular in the late 19th and early 20th centuries. Chautauqua assemblies expanded and spread throughout rural America until the mid-1920s. The Chautauqua br ...

, Elk and Greenwood counties. The sandstones continue into northern Oklahoma.

Flint Hills

The Flint Hills developed on the north–south exposure of Permian

y 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 Osage Hills is a hilly area in Oklahoma, commonly known as ''The Osage''. The name refers to the broad rolling hills and rolling tallgrass prairie and Cross Timbers encompassing Osage County and surrounding areas, including portions of Maye ...

. The Permian limestones contain abundant

weathering Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs '' in situ'' (on site, with little or no movement ...

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

kimberlite Kimberlite is an igneous rock and a rare variant of peridotite. It is most commonly known to be the main host matrix for diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an diamond called the Star of S ...

s occur in Riley and Marshall counties. The kimberlite

diatreme A diatreme, sometimes known as a maar-diatreme volcano, is a volcanic pipe formed by a gaseous explosion. When magma rises up through a crack in Earth's crust and makes contact with a shallow body of groundwater, rapid expansion of heated wate ...

s are of Cretaceous age. No diamonds have been found in the Kansas kimberlite occurrences.

Garnet Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different ...

crystals from the kimberlites have been reported in local stream gravels.

Red Hills

The Red Hills cover a section of southern Kansas in

Clark Clark is an English language surname, ultimately derived from the Latin language, Latin with historical links to England, Scotland, and Ireland ''clericus'' meaning "scribe", "secretary" or a scholar within a religious order, referring to someone ...

Comanche The Comanche or Nʉmʉnʉʉ ( com, Nʉmʉnʉʉ, "the people") are a Native American tribe from the Southern Plains of the present-day United States. Comanche people today belong to the federally recognized Comanche Nation, headquartered in ...

, and Barber counties along the Oklahoma border. The Red Hills are named for their color derived from the Permian

red bed Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain t ...

s which outcrop and underlie the region. The red color is produced by abundant

iron oxide Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of wh ...

s in the weathering sediments. The region is underlain by red shales, siltstones, and sandstones along with interbedded

s and

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 Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

and dolomite produce many

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

s in the area. The Big Basin of Clark County is a 2 km diameter, 35 m 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 Dakota is a sedimentary geologic unit name of formation and group rank in Midwestern North America. The Dakota units are generally composed of sandstones, mudstones, clays, and shales deposited in the Mid-Cretaceous opening of the Wester ...

, the

Greenhorn Limestone The Greenhorn Limestone or Greenhorn Formation is a geologic formation in the Great Plains Region of the United States, dating to the Cenomanian and Turonian ages of the Late Cretaceous period. The formation gives its name to the Greenhorn cycle ...

, 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

concretion A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular ...

s are found in the area. In the western portions of the area the bedrock is

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

iferous

of the Niobrara Formation which includes the Smoky Hill Chalk member noted for abundant fish and

marine reptile Marine reptiles are reptiles which have become secondarily adapted for an aquatic or semiaquatic life in a marine environment. The earliest marine reptile mesosaurus (not to be confused with mosasaurus), arose in the Permian period during th ...

fossils.

High Plains

The western third of Kansas is in the High Plains area. The highest point in Kansas,

Mount Sunflower Mount Sunflower, although not a true mountain, is the highest natural point in the U.S. state of Kansas. At , it is above the state's topographic low point, which lies on the opposite side of the state. Located in Wallace County, it is less tha ...

(), is located in the High Plains physiographic region. The

tectonic uplift Tectonic uplift is the geologic uplift of Earth's surface that is attributed to plate tectonics. While isostatic response is important, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal th ...

of the

during the

resulted in erosion and deposition of vast quantities of non-marine sediments eastward across the High Plains. The

Ogallala Formation The Ogallala Formation is a Miocene to early Pliocene geologic formation in the central High Plains of the western United States and the location of the Ogallala Aquifer. In Nebraska and South Dakota it is also classified as the Ogallala Group. ...

consists of a large wedge of unconsolidated sands and silts that is a significant

aquifer An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characte ...

under the plains. The Ogallala contains a sandstone layer cemented with

opal Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline form ...

. In the southwest corner of the state in Morton County rocks of

age outcrop along the Cimarron River.

Loess Loess (, ; from german: Löss ) is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of Earth's land area is covered by loess or similar deposits. Loess is a periglacial or aeoli ...

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 The Kansas River, also known as the Kaw, is a river in northeastern Kansas in the United States. It is the southwesternmost part of the Missouri River drainage, which is in turn the northwesternmost portion of the extensive Mississippi River dr ...

and east of the Big Blue River, is covered by

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

debris deposited during the Pre-Illinoian glaciations which occurred 600,000 years ago in the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

. The Pennsylvanian and Permian bedrock is buried under thick deposits of glacial debris, largely loess. A variety of

glacial erratic A glacial erratic is glacially deposited rock differing from the type of rock native to the area in which it rests. Erratics, which take their name from the Latin word ' ("to wander"), are carried by glacial ice, often over distances of hundred ...

s were left by the melting glaciers. Many of these are of Sioux Quartzite carried south from the

Sioux Falls, South Dakota Sioux Falls () is the most populous city in the U.S. state of South Dakota and the 130th-most populous city in the United States. It is the county seat of Minnehaha County and also extends into Lincoln County to the south, which continues up ...

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 The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in the western United ...

valley during the Pleistocene Epoch one to two million years ago. The sediments consist largely of sands, silts, and gravels. These include the "Equus beds" aquifer sediments, named for Pleistocene fossils it contains. Also under this area is the Permian Hutchinson salt bed which reaches a thickness of . The area also contains inactive sand dunes.http://www.kgs.ku.edu/Extension/lowlands/lowlands.html Arkansas River Lowlands and Wellington-McPherson Lowlands

Arkansas River Lowlands

The Arkansas River Lowlands follows the course of the

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

The subsurface geology of Kansas consists of several sequences of sedimentary

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...

deposited on the

Pre-Cambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

basement A basement or cellar is one or more Storey, floors of a building that are completely or partly below the storey, ground floor. It generally is used as a utility space for a building, where such items as the Furnace (house heating), furnace, ...

of the

North American Craton North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is ...

. Several regional subsurface structures including five

sedimentary basin Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock. They form when long-term subsiden ...

s exist under Kansas. These structures are important in controlling the vast deposits of

petroleum Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crud ...

and

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon d ...

in the state. The Central Kansas Uplift is a broad arch in the rocks of west central Kansas. The rock units within this arch have been major oil producers. The

Anadarko Basin The Anadarko Basin is a geologic depositional and structural basin centered in the western part of the state of Oklahoma and the Texas Panhandle, and extending into southwestern Kansas and southeastern Colorado. The basin covers an area of . By ...

of southwest Kansas contains significant natural gas. The Sedgwick Basin, the Cherokee Basin and the Forest City Basin of south and east Kansas also produce petroleum and natural gas.

Proterozoic basement

The

Nemaha uplift The Nemaha Ridge (also called the Nemaha Uplift and the Nemaha Anticline) is located in the Central United States. It is a buried structural zone associated with a granite high in the Pre-Cambrian basement that extends from approximately Omaha, ...

is a deep

fault zone In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectoni ...

which runs diagonally across east Kansas and extends from just south of

Omaha, Nebraska Omaha ( ) is the largest city in the U.S. state of Nebraska and the county seat of Douglas County. Omaha is in the Midwestern United States on the Missouri River, about north of the mouth of the Platte River. The nation's 39th-largest ...

Oklahoma City Oklahoma City (), officially the City of Oklahoma City, and often shortened to OKC, is the capital and largest city of the U.S. state of Oklahoma. The county seat of Oklahoma County, it ranks 20th among United States cities in population, and ...

. This fault zone directly overlies a

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies un ...

"high" in the Precambrian basement and is structurally active as the Humboldt Fault. Some fifty miles to the west the southernmost extension of the

Proterozoic The Proterozoic () is a geological eon spanning the time interval from 2500 to 538.8million years ago. It is the most recent part of the Precambrian "supereon". It is also the longest eon of the Earth's geologic time scale, and it is subdivided i ...

Midcontinent Rift System The Midcontinent Rift System (MRS) or Keweenawan Rift is a long geological rift in the center of the North American continent and south-central part of the North American plate. It formed when the continent's core, the North American craton, ...

extends into northeastern Kansas. The northern two-thirds of Kansas is underlain by a Proterozoic sequence known as the Central Plains Orogen. The igneous and metamorphic rocks of this orogenic zone are considered to be an extension of the 1.7 Ga fold belt exposed in Colorado and Wyoming.P. K. Sims and Z. E. Petermar, ''Early Proterozoic Central Plains orogen: A major buried structure in the north-central United States,'' Geology 1986;14;488-491 The southern approximately one-third of the state is underlain by the Southern granite-rhyolite province dating to 1.35 to 1.48 Ga.Ben A. Van der Pluijm, Paul A. Catacosinos, ''Basement and basins of eastern North America,'' Geological Society of America, Special Paper 308, 1996, p. 14

References

External links

Kansas Geological Survey
{{Geology of the United States by political division

Natural history of Kansas