Limestone is a
sedimentary rockSedimentary rock is the type of rock that is formed by sedimentation of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
composed largely of the
mineralA mineral is a naturally occurring solid formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties. A rock, by comparison, is an aggregate of minerals and/or mineraloids, and need not have a specific...
calciteCalcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 470°C, and vaterite is even less stable....
(
calcium carbonateCalcium carbonate is a chemical compound with the chemical formula CaCO
3. It is a common substance found in rock in all parts of the world, and is the main component of shells of marine organisms, snails, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural...
: CaCO
3). The deposition of limestone strata is often a by-product and indicator of biological activity in the
geologicGeology is the science and study of the solid and liquid matter that constitutes the Earth. The field of geology encompasses the study of the composition, structure, physical properties, dynamics, and history of Earth materials, and the processes by which they are formed, moved, and changed...
record.
CalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the Earth's crust...
(along with
nitrogenNitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere.Many industrially important...
,
phosphorusPhosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate rocks. Elemental phosphorus exists in two major forms - white phosphorus and red phosphorus...
, and
potassiumPotassium is the chemical element with the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash...
) is a key mineral to
plantPlants are living organisms belonging to the kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants, known as botany, has identified about 350,000 extant species of plants, defined as seed plants,...
nutrition: soils overlying limestone bedrock tend to be pre-fertilized with calcium. Limestone is an important
stoneIn geology, rock is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
for
masonryMasonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone such as marble, granite, travertine, limestone; concrete block, glass block, and...
and
architectureFor a topical guide to this subject, see Outline of architecture. Architecture is the art and science of designing and constructing buildings and other physical structures for human shelter or use....
, vying with only
graniteGranite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite has a medium to coarse texture, occasionally with some individual crystals larger than the groundmass forming a rock known as porphyry. Granites can be pink to dark gray or even black, depending on their...
and
sandstoneSandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains. Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow,...
to be the most commonly used architectural stone. Limestone is a key ingredient of quicklime,
mortarMortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...
,
cementIn the most general sense of the word, a cement is a binder, a substance which sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term "opus caementicium" to describe masonry which resembled concrete and was made from crushed...
, and
concreteConcrete is a construction material composed of cement as well as other cementitious materials such as fly ash and slag cement, aggregate , water, and chemical admixtures...
. The
solubilitySolubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a liquid solvent to form a homogeneous solution. The solubility of a substance strongly depends on the used solvent as well as on temperature and pressure...
of limestone in water and weak acid solutions leads to important phenomena. Regions overlying limestone bedrock tend to have fewer visible
groundwaterGroundwater is water located beneath the ground surface in soil pore spaces and in the fractures of lithologic formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in...
sources (ponds and streams), as surface water easily drains downward through cracks in the limestone. While draining, water slowly (over thousands or millions of years) enlarges these cracks; dissolving the calcium-carbonate and carrying it away in
solutionIn chemistry, a solution is a homogeneous mixture composed of two or more substances. In such a mixture, a solute is dissolved in another substance, known as a solvent. Gases may dissolve in liquids, for example, carbon dioxide or oxygen in water. Liquids may dissolve in other liquids. Gases can...
. Most well-known natural
caveA cave or cavern is a natural underground void large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and...
systems are through limestone bedrock.
Description
Limestone often contains variable amounts of silica in the form of
chertChert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...
and/or
flintFlint is a hard, sedimentary cryptocrystalline form of the mineral quartz, categorized as a variety of chert. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones. Inside the nodule, flint is usually dark grey, black, green, white, or brown in color, and...
, as well as varying amounts of
clayClay is a naturally occurring material composed primarily of fine-grained minerals, which show plasticity through a variable range of water content, and which can be hardened when dried and/or fired...
,
siltSilt is soil or rock derived granular material of a grain size between sand and clay. Silt may occur as a soil or as suspended sediment in a surface water body...
and
sandSand is a naturally occurring granular material composed of finely divided rock and mineral particles.As the term is used by geologists, sand particles range in diameter from 0.0625 to 2 millimeters. An individual particle in this range size is termed a sand grain...
as disseminations, nodules, or layers within the rock. The primary source of the calcite in limestone is most commonly
marine organismsMarine biology is the scientific study of living organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment...
. These organisms secrete shells that settle out of the water column and are deposited on
oceanAn ocean is a large body of saline water, and a principal component of the hydrosphere. Approximately 75% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
floors as
pelagicAny water in the sea that is not close to the bottom is in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means open sea....
ooze or alternatively are conglomerated in a coral reef (see
lysoclineThe lysocline is a term used in geology, geochemistry and marine biology to denote the depth in the ocean below which the rate of dissolution of calcite increases dramatically....
for information on calcite dissolution). Secondary calcite may also be deposited by
supersaturatedThe term supersaturation refers to a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances...
meteoricMeteorology is the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting . Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the eighteenth century...
waters (
groundwaterGroundwater is water located beneath the ground surface in soil pore spaces and in the fractures of lithologic formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in...
that
precipitatesPrecipitation is the formation of a solid in a solution during a chemical reaction. When the reaction occurs, the solid formed is called the precipitate, and the liquid remaining above the solid is called the supernate...
the material in
caveA cave or cavern is a natural underground void large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and...
s). This produces
speleothemA speleothem , commonly known as a cave formation, is a secondary mineral deposit formed in a cave. Speleothems are typically formed in limestone or dolostone solutional caves.-Origin and composition:...
s such as
stalagmiteA stalagmite is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. The corresponding formation on the ceiling of a cave is known as a stalactite...
s and
stalactiteA stalactite is a type of speleothem that hangs from the ceiling or wall of limestone caves. It is a type of dripstone.- Formation and type:...
s. Another form taken by calcite is that of oolites (oolitic limestone) which can be recognized by its granular appearance.
Limestone makes up about 10% of the total volume of all sedimentary rocks. Limestones may also form in both
lacustrineLacustrine means "of a lake" or "relating to a lake".Specifically, it may refer to:*Lacustrine plain*Lacustrine delta-See also:*Limnic, of or relating to freshwater*Palustrine, of or relating to a marsh*Riverine, of or relating to a river...
and
evaporiteEvaporites are water-soluble mineral sediments that result from the evaporation of bodies of surficial water. Evaporites are considered sedimentary rocks.- Formation of evaporite rocks :...
depositional environmentsIn geology, sedimentary depositional environment describes the combination of physical, chemical and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will be formed after lithification, if the sediment is preserved in the rock...
.
Calcite can be either
dissolvedSolvation, also sometimes called dissolution, is the process of attraction and association of molecules of a solvent with molecules or ions of a solute...
by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved
ionAn ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge...
concentrations. Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases.
When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures.
KarstKilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after a Yugoslavian geologist Karst. It will consist of about 30 individual...
topographyTopography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
and
caveA cave or cavern is a natural underground void large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and...
s develop in carbonate rocks due to their
solubilitySolubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a liquid solvent to form a homogeneous solution. The solubility of a substance strongly depends on the used solvent as well as on temperature and pressure...
in dilute
acidAn acid is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity greater than in pure water, i.e. a pH less than 7.0...
ic
groundwaterGroundwater is water located beneath the ground surface in soil pore spaces and in the fractures of lithologic formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in...
. Cooling groundwater or mixing of different groundwaters will also create conditions suitable for cave formation.
Coastal limestones are often eroded by organisms which bore into the rock by various means. This process is known as
bioerosionBioerosion describes the erosion of hard ocean substrates – and less often terrestrial substrates – by living organisms. Marine bioerosion can be caused by mollusks, polychaete worms, phoronids, sponges, crustaceans, echinoids, and fish; it can occur on coastlines, on coral reefs, and...
. It is most common in the tropics, and it is known throughout the fossil record (see Taylor and Wilson, 2003).
Because of impurities, such as
clayClay is a naturally occurring material composed primarily of fine-grained minerals, which show plasticity through a variable range of water content, and which can be hardened when dried and/or fired...
, sand, organic remains,
iron oxideIron oxides are chemical compounds composed of iron and oxygen. Altogether, there are sixteen known iron oxides and oxyhydroxides.-Oxides:* FeO, iron oxide, * Fe3O4, iron oxide,...
and other materials, many limestones exhibit different colors, especially on
weatheredWeathering is the decomposition of Earth's rocks, soils and minerals through direct contact with the planet's atmosphere. Weathering occurs in situ, or "with no movement", and thus should not be confused with erosion, which involves the movement of rocks and minerals by agents such as water, ice,...
surfaces. Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite,
quartzQuartz is the second most abundant mineral in the Earth's continental crust . It is made up of a continuous framework of SiO
4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO
2.There are many different varieties of...
,
dolomiteDolomite is the name of a sedimentary carbonate rock and a mineral, both composed of calcium magnesium carbonate CaMg
2 found in crystals....
or
bariteBaryte, or barite, is a mineral consisting of barium sulfate. The baryte group consists of baryte, celestine, anglesite and anhydrite. Baryte itself is generally white or colorless, and is the main source of barium...
may line small cavities in the rock.
FolkThe Folk classification, devised by R. L. Folk in 1959, is a technical descriptive classification of calcareous sedimentary rocks. It details the relative proportions of allochems in the rock and the type of matrix...
and
DunhamThe Dunham classification system for carbonate sedimentary rocks was devised by Kingsley Charles Dunham in 1964, and refined by Embry and Klovan in 1971 to include sediments that were organically bound during deposition....
classifications are used to describe limestones more precisely.
TravertineTravertine is a terrestrial sedimentary rock, formed by the precipitation of carbonate minerals from geothermally heated hot-springs. Similar deposits formed from ambient temperature water are known as tufa.-Features:...
is a banded, compact variety of limestone formed along streams, particularly where there are waterfalls and around
hotA hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are hot springs all over the earth, on every continent and even under the oceans and seas.-Definitions:...
or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution that is supersaturated with chemical constituents of calcite.
TufaTufa is a terrestrial sedimentary rock, formed by the precipitation of carbonate minerals from ambient temperature water bodies. Geothermally heated hot-springs sometimes produce similar carbonate deposits known as travertine...
, a porous or cellular variety of travertine, is found near waterfalls.
CoquinaCoquina is an incompletely consolidated sedimentary rock. Coquina was formed in association with marine reefs and is a variety of "coral rag", technically a subset of limestone.-Composition and distribution:...
is a poorly consolidated limestone composed of pieces of
coralCorals are marine organisms from the class Anthozoa and exist as small sea anemone-like polyps, typically in colonies of many identical individuals...
or shells.
During regional
metamorphismMetamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Both mineralogical, chemical and crystallographic changes can occur during this process.Three types...
that occurs during the mountain building process (
orogenyOrogeny refers to natural mountain building, and may be studied as a tectonic structural event, as a geographical event, and a chronological event...
) limestone recrystallizes into
marbleMarble is a non foliated metamorphic rock resulting from the metamorphism of limestone, composed mostly of calcite . It is extensively used for sculpture, as a building material, and in many other applications...
.
Limestone is a
parent materialParent material, in soil science, means the underlying geological material in which soil horizons form. Soils typically get a great deal of structure and minerals from their parent material...
of Mollisol
soilSoil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics. It is composed of particles of broken rock that have been altered by chemical and...
group.
Limestone landscape
Limestone is partially soluble, especially in
acidAn acid is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity greater than in pure water, i.e. a pH less than 7.0...
, and therefore forms many
erosionErosion is a gravity driven process that moves solids in the natural environment or their source and deposits them elsewhere...
al
landformIn the earth sciences and geology sub-fields, a landform or physical feature comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...
s. These include
limestone pavementA limestone pavement is a natural karst landform consisting of a flat, incised surface of exposed limestone that resembles an artificial pavement....
s, pot holes,
cenoteA cenote is a sinkhole with exposed rocky edges containing groundwater. It is typically found in the Yucatán Peninsula and some nearby Caribbean islands...
s,
caveA cave or cavern is a natural underground void large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and...
s and gorges. Such erosion landscapes are known as karsts. Limestone is less resistant than most igneous rocks, but more resistant than most other sedimentary rocks. Limestone is therefore usually associated with hills and
downlandA downland is an area of open chalk hills. This term is especially used to describe the chalk countryside in southern England. Areas of downland are often referred to as Downs....
and occurs in regions with other sedimentary rocks, typically
clayClay is a naturally occurring material composed primarily of fine-grained minerals, which show plasticity through a variable range of water content, and which can be hardened when dried and/or fired...
s.
Bands of limestone emerge from the
EarthEarth is the third planet from the Sun. It is the fifth largest of the eight planets in the solar system, and the largest of the terrestrial planets in the Solar System in terms of diameter, mass and density...
's surface in often spectacular rocky outcrops and
islandAn island or isle is any piece of land that is surrounded by water. Very small islands such as emergent land features on atolls are called islets. A key or cay is another name for a small island or islet. An island in a river or lake may be called an eyot, .There are two main types of islands:...
s. Examples include the
BurrenThe Burren is a karst-landscape region in northwest County Clare, in Ireland. It is one of the largest karst landscapes in Europe. The region measures approximately 250 square kilometres and is enclosed roughly within the circle made by the villages Ballyvaughan, Kinvara, Tubber, Corofin,...
in Co. Clare, Ireland; the
Verdon GorgeThe Verdon Gorge , in south-eastern France , is a river canyon that is considered by many to be Europe's most beautiful. It is about 25 kilometers long and up to 700 meters deep...
in
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
;
Malham CoveMalham Cove is a natural limestone formation near Malham, North Yorkshire, England. A well-known beauty spot, it comprises a huge, curved limestone cliff at the head of a valley, with a fine area of limestone pavement at the top....
in
North YorkshireNorth Yorkshire is a non-metropolitan or shire county, located in the Yorkshire and the Humber region of England, and a ceremonial county in that region and also partly in North East England. Created in 1974 by the Local Government Act 1972 it covers an area of , making it the largest ceremonial...
and the
Isle of WightThe Isle of Wight is an English island and a county, located 3-5 miles from the south coast of the mainland, in the English Channel. It is separated from mainland England by the Solent and is situated south of the county of Hampshire...
,
EnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...
; on
FåröFårö is a small Baltic Sea island north of the province of Gotland, off Sweden's southeastern coast. It is the second-largest island in the province. It has a population of less than 600, and has become a popular summer resort. The island has no banks, post offices, medical services or police...
near the Swedish island of
Gotland' is a county, province, municipality and diocese of Sweden and the largest island in the Baltic Sea. At 3,140 square kilometers in area, it makes up less than one percent of Sweden's total land area. The region also includes the small islands of Fårö and Gotska Sandön to the north, and the tiny...
, the
Niagara EscarpmentThe Niagara Escarpment is a long escarpment, or cuesta, in the United States and Canada that runs westward from New York State, through Ontario, Michigan, Wisconsin and Illinois...
in
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
/
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Notch Peak in
UtahUtah is a western state of the United States. It was the 45th state admitted to the Union, on January 4, 1896. Approximately 80 percent of Utah's 2,736,424 people live along the Wasatch Front, centering around Salt Lake City. In contrast, vast expanses of the state are nearly uninhabited, making...
, the Ha Long Bay National Park in
VietnamVietnam , officially the Socialist Republic of Vietnam , is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea to the east...
and the hills around Lijiang river and Guilin city in China.
Unique habitats are found on
alvarAn alvar or pavement barren is a biological environment based on a limestone plain with thin or no soil and, as a result, sparse vegetation. In the United Kingdom this landform is called a limestone pavement. This challenging habitat supports a community of rare plants and animals, including...
s, extremely level expanses of limestone with thin soil mantles. The largest such expanse in
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
is the
Stora AlvaretThe Stora Alvaret is a limestone barren plain on the island of Öland, Sweden. Because of the thin soil mantle and high pH levels, a great assortment of vegetation is found including numerous rare species. Stora Alvaret has been designated as a World Heritage Site by UNESCO due to its...
on the island of
Öland' is the second largest Swedish island and the smallest of the traditional provinces of Sweden. Öland has an area of 1,342 km² and is located in the Baltic Sea just off the coast of Småland. There are 25,000 inhabitants on the island and it is connected to the mainland across the Kalmar Strait...
,
SwedenSweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...
. Another area with large quantities of limestone is the island of
Gotland' is a county, province, municipality and diocese of Sweden and the largest island in the Baltic Sea. At 3,140 square kilometers in area, it makes up less than one percent of Sweden's total land area. The region also includes the small islands of Fårö and Gotska Sandön to the north, and the tiny...
, Sweden. Huge quarries in northwestern Europe, such as those of Mount Saint Peter (Belgium/Netherlands), extend for more than a hundred kilometers.
The world's largest limestone quarry is at
Michigan Limestone and Chemical CompanyMichigan Limestone and Chemical Company operated the world's largest limestone quarry located near Rogers City, Michigan. It was founded in 1910, however production didn't begin until 1912...
in
Rogers City, MichiganRogers City is a city in the U.S. state of Michigan. As of the 2000 census, the city population was 3,322. It is the county seat of Presque Isle County. The city is adjacent to Rogers Township, but is politically independent....
.
Uses
Limestone is very common in
architectureFor a topical guide to this subject, see Outline of architecture. Architecture is the art and science of designing and constructing buildings and other physical structures for human shelter or use....
, especially in
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
and
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
. Many landmarks across the world, including the
Great PyramidThe Great Pyramid of Giza is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now Cairo, Egypt, and is the only one of the Seven Wonders of the Ancient World that survives substantially intact...
and its associated
ComplexThe Giza Necropolis stands on the Giza Plateau, on the outskirts of Cairo, Egypt. This complex of ancient monuments includes the three pyramids known as the Great Pyramids, along with the massive sculpture known as the Great Sphinx...
in
GizaGiza is most famous as the location of the Giza Plateau: the site of some of the most impressive ancient monuments in the world, including a complex of ancient Egyptian royal mortuary and sacred structures, including the Great Sphinx, the Great Pyramid of Giza, and a number of other large pyramids...
,
EgyptEgypt , officially the Arab Republic of Egypt, is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Western Asia...
, are made of limestone. So many buildings in
Kingston, Ontario, CanadaKingston, Ontario is a Canadian city located in the eastern portion of Southern Ontario, where Lake Ontario runs into the St. Lawrence River and the Thousand Islands begin.Kingston is the county seat of Frontenac County...
were constructed from it that it is nicknamed the 'Limestone City'. On the island of
MaltaMalta , officially the Republic of Malta , is a densely populated developed European country in the European Union. The Southern European island nation is an archipelago that includes the inhabited islands of Malta, Gozo and Comino, along with a number of smaller, uninhabited islands...
, a variety of limestone called Globigerina limestone was for a long time the only building material available, and is still very frequently used on all types of buildings and sculptures. Limestone is readily available and relatively easy to cut into blocks or more elaborate carving. It is also long-lasting and stands up well to exposure. However, it is a very heavy material, making it impractical for tall buildings, and relatively expensive as a building material.
Limestone was most popular in the late 19th and early 20th centuries.
Train stationA railway station, train station, railroad station, or station yard is a facility at which passengers may board and alight from trains, and/or where rail-transported freight may be loaded or unloaded. Historically, the term depot has also been employed in North America...
s,
bankA bank is a financial institution licensed by a government. Its primary activities include borrowing and lending money.Many other financial activities were allowed over time. For example banks are important players in financial markets and offer financial services such as investment funds...
s and other structures from that era are normally made of limestone. Limestone is used as a facade on some
skyscraperA skyscraper is a tall, continuously habitable building. There is no official definition or height above which a building may clearly be classified as a skyscraper...
s, but only in thin plates for covering rather than solid blocks. In the United States,
IndianaIndiana is a U.S. state, the 19
th admitted to the Union. It is located in the Great Lakes region, and with approximately 6.3 million residents, is ranked 16
th in population and 17
th in population density. Indiana is ranked 38
th in land area, and is the...
, most notably the Bloomington area, has long been a source of high quality quarried limestone, called
Indiana limestoneIndiana Limestone or Bedford Limestone is a common term for Salem limestone, a geological formation primarily quarried in south central Indiana between Bloomington and Bedford. Bloomington, Indiana has been noted to have the highest quality quarried limestone in the United States. Salem limestone,...
. Many famous buildings in
London[]London is the capital of England and the United Kingdom. It has been a major settlement for two millennia, and the history of London goes back to its founding by the Romans, when it was named Londinium. London's core, the ancient City of London, the 'square mile', retains its medieval boundaries...
are built from Portland limestone.
Limestone was also a very popular building block in the Middle Ages in the areas where it occurred since it is hard, is durable, and commonly occurs in easily accessible surface exposures. Many medieval churches and castles in Europe are made of limestone.
Beer stoneNot to be confused with beerstone, the scale that forms on the inside of beer storage equipment.Beer stone is a creamy-white, fine-textured limestone that takes its name from the town of Beer, Devon, where it was quarried and mined from Roman times. It is also found in other places in south-west...
was a popular kind of limestone for medieval buildings in southern England.
Limestone and marble are very reactive to acid solutions, making
acid rainAcid rain is rain or any other form of precipitation that is unusually acidic, i.e. elevated levels of hydrogen ions . It has harmful effects on plants, aquatic animals, and infrastructure. Acid rain is mostly caused by emissions of compounds of sulfur, nitrogen, and carbon which react with the...
a significant problem. Many limestone statues and building surfaces have suffered severe damage due to acid rain. Acid-based cleaning chemicals can also etch limestone, which should only be cleaned with a neutral or mild alkaline-based cleaner.
Other uses include:
- The manufacture of quicklime (calcium oxide) and slaked lime (calcium hydroxide);
- Cement
In the most general sense of the word, a cement is a binder, a substance which sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term "opus caementicium" to describe masonry which resembled concrete and was made from crushed...
and mortarMortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...
;
- Pulverized limestone is used as a soil conditioner to neutralize acidic soil conditions;
- Crushed for use as aggregate
Construction aggregate, or simply "aggregate", is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates...
—the solid base for many roads;
- Geological formations of limestone are among the best petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid found in rock formations in the Earth consisting of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds.The term "petroleum" was first used in the treatise De Natura Fossilium, published in...
reservoirs;
- As a reagent
A reagent or reactant is a substance or compound consumed during a chemical reaction. Solvents and catalysts, although they are involved in the reaction, are usually not referred to as reactants....
in desulfurizationsFlue gas desulfurization is commonly known as FGD and is the technology used for removing sulfur dioxide from the exhaust flue gases in power plants that burn coal or oil to produce steam for the steam turbines that drive their electricity generators.Sulfur dioxide is responsible for acid rain...
;
- Glass making, in some circumstances;
- Added to paper, plastics, paint, tiles, and other materials as both white pigment and a cheap filler.
- Toothpaste
- Suppression of methane explosions in underground coal mines
- Added to bread and cereals as a source of calcium
- Calcium supplement for poultry (when ground up)
- Remineralizing and increasing the alkalinity of purified water to prevent pipe corrosion and to return essential nutrients
See also
- Calcium carbonate
Calcium carbonate is a chemical compound with the chemical formula CaCO
3. It is a common substance found in rock in all parts of the world, and is the main component of shells of marine organisms, snails, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural...
- Chalk
Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. It forms under relatively deep marine conditions from the gradual accumulation of minute calcite plates shed from micro-organisms called coccolithophores. It is common to find flint and chert...
- Coral sand
Coral sand is sand of particles originating in tropical and sub-tropical marine environments from bioerosion of limestone skeletal material of marine organisms. One example of this process is that of parrot fishes which bite off pieces of coral, digest the living tissue, and excrete the inorganic...
- In Praise of Limestone
"In Praise of Limestone" is a poem written by W. H. Auden in Italy in May 1948. Central to his canon and considered one of Auden's finest poems, it has been the subject of diverse scholarly interpretations. Auden's limestone landscape has been interpreted as an allegory of Mediterranean...