Limestone: Difference between revisions
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HEY!!!!!!!!!!!!!!!!!!!!!!!!! OMGGGGGGG!!!!!!!!!! LIMESTONE ROCK ROCKS SOCKS!!!!!!!!!!!!!!! =))))))))))))))))))))))))))))))))) OMG!!! WATCH THE JULIE AND LAUREN SHOW ON YOUTUBE!!! |
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{{otheruses}} |
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[[Image:Limestone cropping.jpg|thumb|right|Limestone cropping at [[São Pedro de Moel]] beach, [[Marinha Grande]], Portugal.]] |
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[[Image:IronImpregnationsLimestone2.jpg|thumb|right|Iron impregnations in limestone]] |
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[[Image:OrdOutcropTN.JPG|thumb|right|A stratigraphic section of [[Ordovician]] limestone exposed in central [[Tennessee]], U.S. The less-resistant and thinner beds are composed of [[shale]]]] |
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[[Image:CarmelOoids.jpg|thumb|right|Thin-section view of a Middle [[Jurassic]] limestone in southern Utah. The round grains are [[ooid]]s; the largest is 1.2 mm in diameter. This limestone is an oosparite.]] |
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'''Limestone''' is a [[sedimentary rock]] composed largely of the [[mineral]] [[calcite]] ([[calcium carbonate]]: CaCO<sub>3</sub>). |
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== Description== |
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Limestone often contains variable amounts of [[silica]] in the form of [[chert]] and/or [[flint]], as well as varying amounts of [[clay]], [[silt]] and [[sand]] as disseminations, nodules, or layers within the rock. The primary source of the calcite in limestone is most commonly [[marine biology|marine organisms]]. These organisms secrete shells that settle out of the water column and are deposited on [[ocean]] floors as [[Pelagic zone|pelagic]] ooze or alternatively are conglomerated in a coral reef (see [[lysocline]] for information on calcite dissolution). Secondary calcite may also be deposited by [[Supersaturation|supersaturated]] [[Meteorology|meteoric]] waters ([[groundwater]] that [[Precipitation (chemistry)|precipitates]] the material in [[cave]]s). This produces [[speleothem]]s such as [[stalagmite]]s and [[stalactite]]s. Another form taken by calcite is that of [[oolite]]s (oolitic limestone) which can be recognized by its granular appearance. |
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Limestone makes up about 10% of the total volume of all sedimentary rocks.<ref> {{cite web |url=http://www.mine-engineer.com/mining/mineral/calcite.htm | title=Calcite | accessdate=2008-02-13}}</ref><ref> {{cite web |url=http://encarta.msn.com/encyclopedia_761565838/Limestone_(mineral).html | title=Limestone (mineral) |accessdate=2008-02-13}}</ref> Limestones may also form in both [[lacustrine]] and [[evaporite]] [[Sedimentary depositional environment|depositional environments]]<ref>[http://jgs.lyellcollection.org:/cgi/content/abstract/156/3/535]|Trewin,N.H. & Davidson,R.G. 1999. Lake-level changes, sedimentation and faunas in a Middle Devonian basin-margin fish bed, Journal Geological Society, 156, 535-548</ref><ref>[http://www.glossary.oilfield.slb.com/Display.cfm?Term=evaporite Oilfield Glossary: Term 'evaporite'<!-- Bot generated title -->]</ref>. |
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Calcite can be either [[solvation|dissolved]] by groundwater or [[precipitate]]d by groundwater, depending on several factors including the water temperature, [[acidity|pH]], and dissolved [[ion]] concentrations. Calcite exhibits an unusual characteristic called [[retrograde solubility]] in which it becomes less soluble in water as the temperature increases. |
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When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. |
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[[Karst]] [[topography]] and [[cave]]s develop in carbonate rocks due to their [[solubility]] in dilute [[acid]]ic [[groundwater]]. Cooling groundwater or mixing of different groundwaters will also create conditions suitable for cave formation. |
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Coastal limestones are often eroded by organisms which bore into the rock by various means. This process is known as [[bioerosion]]. It is most common in the tropics, and it is known throughout the [[fossil record]] (see Taylor and Wilson, 2003). |
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Because of impurities, such as [[clay]], sand, organic remains, [[iron oxide]] and other materials, many limestones exhibit different colors, especially on [[Weathering|weathered]] surfaces. Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, [[quartz]], [[dolomite]] or [[barite]] may line small cavities in the rock. [[Folk classification|Folk]] and [[Dunham classification|Dunham]] classifications are used to describe limestones more precisely. |
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[[Travertine]] is a banded, compact variety of limestone formed along streams, particularly where there are waterfalls and around [[Hot spring|hot]] or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution that is supersaturated with chemical constituents of calcite. [[Tufa]], a porous or cellular variety of travertine, is found near waterfalls. [[Coquina]] is a poorly consolidated limestone composed of pieces of [[coral]] or [[Animal shell|shell]]s. |
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During regional [[metamorphism]] that occurs during the mountain building process ([[orogeny]]) limestone recrystallizes into [[marble]]. |
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Limestone is a [[parent material]] of [[Mollisol]] [[soil]] group. |
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== Limestone landscape == |
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{{main|Karst topography}} |
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Limestone is partially soluble, especially in [[acid]], and therefore forms many [[erosion]]al [[landform]]s. These include [[limestone pavement]]s, [[pot hole]]s, [[cenote]]s, [[cave]]s and [[gorge]]s. Such erosion landscapes are known as karsts. Limestone is less [[resistance (geology)|resistant]] than most [[igneous]] rocks, but more resistant than most other [[sedimentary rocks]]. Limestone is therefore usually associated with hills and [[downland]] and occurs in regions with other sedimentary rocks, typically [[clay]]s. |
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Bands of limestone emerge from the [[Earth]]'s surface in often spectacular rocky outcrops and [[island]]s. Examples include the [[The Burren|Burren]] in Co. Clare, Ireland; the [[Verdon Gorge]] in [[France]]; [[Malham Cove]] in [[North Yorkshire]] and the [[Isle of Wight]]<ref>{{cite web | url=http://www.iwight.com/council/documents/policies_and_plans/udp/2002_pdfs/minerals.pdf| title=Isle of Wight, Minerals | accessdate=2006-10-08}}</ref>, [[England]]; on [[Fårö]] near the Swedish island of [[Gotland]], the [[Niagara Escarpment]] in [[Canada]]/[[United States]], Notch Peak in [[Utah]], and the [[Ha Long Bay]] National Park in [[Vietnam]]. |
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Unique habitats are found on [[alvar]]s, extremely level expanses of limestone with thin soil mantles. The largest such expanse in [[Europe]] is the [[Stora Alvaret]] on the island of [[Oland]], [[Sweden]]. Another area with large quantities of limestone is the island of [[Gotland]], Sweden. Huge quarries in northwestern Europe, such as those of Mount Saint Peter (Belgium/Netherlands), extend for more than a hundred kilometers. |
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The world's largest limestone quarry is at [[Michigan Limestone and Chemical Company]] in [[Rogers City, Michigan]].<ref>[http://www.michmarkers.com/startup.asp?startpage=S0214.htm Michigan Markers]</ref> |
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== Uses of limestone == |
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Limestone is very common in [[architecture]], especially in [[North America]] and [[Europe]]. Many landmarks across the world, including the pyramids in [[Egypt]], are made of limestone. So many buildings in [[Kingston, Ontario|Kingston, Ontario, Canada]] were constructed from it that it is nicknamed the 'Limestone City'. <ref> {{cite web |url= http://www.citylifeontario.com/kingston/ | title=Welcome to the Limestone City |accessdate=2008-02-13}} </ref> On the island of [[Malta]], 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. |
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[[Image:Riley (Kansas) County Courthouse 1.jpg|thumb|right|Courthouse built of limestone in [[Manhattan, Kansas]]]] |
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[[Image:Litography press with map of Moosburg 01.jpg|thumb|right|A limestone plate with a negative map of [[Moosburg]] in [[Bavaria]] is prepared for a [[lithography]] print]] |
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Limestone was most popular in the late 19th and early 20th centuries. [[Train station]]s, [[bank]]s and other structures from that era are normally made of limestone. Limestone is used as a facade on some [[skyscraper]]s, but only in thin plates for covering rather than solid blocks. In the United States, [[Indiana]], most notably the Bloomington area, has long been a source of high quality quarried limestone, called [[Indiana limestone]]. Many famous buildings in [[London]] are built from [[Portland limestone]]. |
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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 stone]] was a popular kind of limestone for medieval buildings in southern England. |
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Limestone and marble are very reactive to acid solutions, making [[acid rain]] 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. |
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Other uses include: |
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* The manufacture of [[quicklime]] (calcium oxide) and [[slaked lime]] (calcium hydroxide); |
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* [[Cement]] and [[mortar (masonry)|mortar]]; |
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* Pulverized limestone is used as a soil conditioner to neutralize acidic soil conditions; |
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* Crushed for use as [[construction aggregate|aggregate]]—the solid base for many roads; |
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* [[Geological formation]]s of limestone are among the best [[petroleum]] reservoirs; |
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* As a [[reagent]] in [[flue gas desulfurization|desulfurizations]]; |
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* Glass making, in some circumstances; |
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* Added to paper, plastics, paint, tiles, and other materials as both white pigment and a cheap filler. |
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* Toothpaste |
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* Suppression of methane explosions in underground coal mines |
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* Added to bread and cereals as a source of calcium |
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== Notes == |
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<!-- this 'empty' section displays references defined elsewhere --> |
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{{reflist}} |
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== References == |
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* Taylor, P.D. and Wilson, M.A., 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103.[http://www.wooster.edu/geology/Taylor%26Wilson2003.pdf] |
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== See also == |
== See also == |
Revision as of 19:44, 9 December 2008
This article's lead section may be too short to adequately summarize the key points. |
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Limestone_cropping.jpg/220px-Limestone_cropping.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/48/IronImpregnationsLimestone2.jpg/220px-IronImpregnationsLimestone2.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/76/CarmelOoids.jpg/220px-CarmelOoids.jpg)
Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO3).
Description
Limestone often contains variable amounts of silica in the form of chert and/or flint, as well as varying amounts of clay, silt and sand as disseminations, nodules, or layers within the rock. The primary source of the calcite in limestone is most commonly marine organisms. These organisms secrete shells that settle out of the water column and are deposited on ocean floors as pelagic ooze or alternatively are conglomerated in a coral reef (see lysocline for information on calcite dissolution). Secondary calcite may also be deposited by supersaturated meteoric waters (groundwater that precipitates the material in caves). This produces speleothems such as stalagmites and stalactites. 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.[1][2] Limestones may also form in both lacustrine and evaporite depositional environments[3][4].
Calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion 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.
Karst topography and caves develop in carbonate rocks due to their solubility in dilute acidic groundwater. 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 bioerosion. 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 clay, sand, organic remains, iron oxide and other materials, many limestones exhibit different colors, especially on weathered surfaces. Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock. Folk and Dunham classifications are used to describe limestones more precisely.
Travertine is a banded, compact variety of limestone formed along streams, particularly where there are waterfalls and around hot or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution that is supersaturated with chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls. Coquina is a poorly consolidated limestone composed of pieces of coral or shells.
During regional metamorphism that occurs during the mountain building process (orogeny) limestone recrystallizes into marble.
Limestone is a parent material of Mollisol soil group.
Limestone landscape
Limestone is partially soluble, especially in acid, and therefore forms many erosional landforms. These include limestone pavements, pot holes, cenotes, caves 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 downland and occurs in regions with other sedimentary rocks, typically clays.
Bands of limestone emerge from the Earth's surface in often spectacular rocky outcrops and islands. Examples include the Burren in Co. Clare, Ireland; the Verdon Gorge in France; Malham Cove in North Yorkshire and the Isle of Wight[5], England; on Fårö near the Swedish island of Gotland, the Niagara Escarpment in Canada/United States, Notch Peak in Utah, and the Ha Long Bay National Park in Vietnam.
Unique habitats are found on alvars, extremely level expanses of limestone with thin soil mantles. The largest such expanse in Europe is the Stora Alvaret on the island of Oland, Sweden. Another area with large quantities of limestone is the island of Gotland, 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 Company in Rogers City, Michigan.[6]
Uses of limestone
Limestone is very common in architecture, especially in North America and Europe. Many landmarks across the world, including the pyramids in Egypt, are made of limestone. So many buildings in Kingston, Ontario, Canada were constructed from it that it is nicknamed the 'Limestone City'. [7] On the island of Malta, 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.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/6a/Riley_%28Kansas%29_County_Courthouse_1.jpg/220px-Riley_%28Kansas%29_County_Courthouse_1.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Litography_press_with_map_of_Moosburg_01.jpg/220px-Litography_press_with_map_of_Moosburg_01.jpg)
Limestone was most popular in the late 19th and early 20th centuries. Train stations, banks and other structures from that era are normally made of limestone. Limestone is used as a facade on some skyscrapers, but only in thin plates for covering rather than solid blocks. In the United States, Indiana, most notably the Bloomington area, has long been a source of high quality quarried limestone, called Indiana limestone. Many famous buildings in London 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 stone was a popular kind of limestone for medieval buildings in southern England.
Limestone and marble are very reactive to acid solutions, making acid rain 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 and mortar;
- Pulverized limestone is used as a soil conditioner to neutralize acidic soil conditions;
- Crushed for use as aggregate—the solid base for many roads;
- Geological formations of limestone are among the best petroleum reservoirs;
- As a reagent in desulfurizations;
- 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
Notes
- ^ "Calcite". Retrieved 2008-02-13.
- ^ "Limestone (mineral)". Retrieved 2008-02-13.
- ^ [1]|Trewin,N.H. & Davidson,R.G. 1999. Lake-level changes, sedimentation and faunas in a Middle Devonian basin-margin fish bed, Journal Geological Society, 156, 535-548
- ^ Oilfield Glossary: Term 'evaporite'
- ^ "Isle of Wight, Minerals" (PDF). Retrieved 2006-10-08.
- ^ Michigan Markers
- ^ "Welcome to the Limestone City". Retrieved 2008-02-13.
References
- Taylor, P.D. and Wilson, M.A., 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103.[2]
See also
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)