80-687: Pinus nigra , the Austrian pine or black pine , is a moderately variable species of pine , occurring across Southern Europe from the Iberian Peninsula to the eastern Mediterranean, on the Anatolian peninsula of Turkey, Corsica and Cyprus, as well as Crimea and in the high mountains of Northwest Africa. The world's oldest black pine, located in the Banaz district of Uşak, Türkiye, is estimated to be 1000 years old. This makes it significant in
160-455: A Mohs hardness of 2 to 4, dense limestone can have a crushing strength of up to 180 MPa . For comparison, concrete typically has a crushing strength of about 40 MPa. Although limestones show little variability in mineral composition, they show great diversity in texture. However, most limestone consists of sand-sized grains in a carbonate mud matrix. Because limestones are often of biological origin and are usually composed of sediment that
240-463: A bloom of cyanobacteria or microalgae . However, stable isotope ratios in modern carbonate mud appear to be inconsistent with either of these mechanisms, and abrasion of carbonate grains in high-energy environments has been put forward as a third possibility. Formation of limestone has likely been dominated by biological processes throughout the Phanerozoic , the last 540 million years of
320-434: A carbonate rock outcrop can be estimated in the field by etching the surface with dilute hydrochloric acid. This etches away the calcite and aragonite, leaving behind any silica or dolomite grains. The latter can be identified by their rhombohedral shape. Crystals of calcite, quartz , dolomite or barite may line small cavities ( vugs ) in the rock. Vugs are a form of secondary porosity, formed in existing limestone by
400-616: A central quartz grain or carbonate mineral fragment. These likely form by direct precipitation of calcium carbonate onto the ooid. Pisoliths are similar to ooids, but they are larger than 2 mm in diameter and tend to be more irregular in shape. Limestone composed mostly of ooids is called an oolite or sometimes an oolitic limestone . Ooids form in high-energy environments, such as the Bahama platform, and oolites typically show crossbedding and other features associated with deposition in strong currents. Oncoliths resemble ooids but show
480-449: A change in environment that increases the solubility of calcite. Dense, massive limestone is sometimes described as "marble". For example, the famous Portoro "marble" of Italy is actually a dense black limestone. True marble is produced by recrystallization of limestone during regional metamorphism that accompanies the mountain building process ( orogeny ). It is distinguished from dense limestone by its coarse crystalline texture and
560-949: A composition reflecting the organisms that produced them and the environment in which they were produced. Low-magnesium calcite skeletal grains are typical of articulate brachiopods , planktonic (free-floating) foraminifera, and coccoliths . High-magnesium calcite skeletal grains are typical of benthic (bottom-dwelling) foraminifera, echinoderms , and coralline algae . Aragonite skeletal grains are typical of molluscs , calcareous green algae , stromatoporoids , corals , and tube worms . The skeletal grains also reflect specific geological periods and environments. For example, coral grains are more common in high-energy environments (characterized by strong currents and turbulence) while bryozoan grains are more common in low-energy environments (characterized by quiet water). Ooids (sometimes called ooliths) are sand-sized grains (less than 2mm in diameter) consisting of one or more layers of calcite or aragonite around
640-412: A considerable fraction of the limestone bed. At depths greater than 1 km (0.62 miles), burial cementation completes the lithification process. Burial cementation does not produce stylolites. When overlying beds are eroded, bringing limestone closer to the surface, the final stage of diagenesis takes place. This produces secondary porosity as some of the cement is dissolved by rainwater infiltrating
720-483: A drop of dilute hydrochloric acid is dropped on it. Dolomite is also soft but reacts only feebly with dilute hydrochloric acid, and it usually weathers to a characteristic dull yellow-brown color due to the presence of ferrous iron. This is released and oxidized as the dolomite weathers. Impurities (such as clay , sand, organic remains, iron oxide , and other materials) will cause limestones to exhibit different colors, especially with weathered surfaces. The makeup of
800-637: A few million years, as this is the most stable form of calcium carbonate. Ancient carbonate formations of the Precambrian and Paleozoic contain abundant dolomite, but limestone dominates the carbonate beds of the Mesozoic and Cenozoic . Modern dolomite is quite rare. There is evidence that, while the modern ocean favors precipitation of aragonite, the oceans of the Paleozoic and middle to late Cenozoic favored precipitation of calcite. This may indicate
880-455: A few thousand years. As rainwater mixes with groundwater, aragonite and high-magnesium calcite are converted to low-calcium calcite. Cementing of thick carbonate deposits by rainwater may commence even before the retreat of the sea, as rainwater can infiltrate over 100 km (60 miles) into sediments beneath the continental shelf. As carbonate sediments are increasingly deeply buried under younger sediments, chemical and mechanical compaction of
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#1732772383158960-490: A high percentage of the mineral dolomite , CaMg(CO 3 ) 2 . Magnesian limestone is an obsolete and poorly-defined term used variously for dolomite, for limestone containing significant dolomite ( dolomitic limestone ), or for any other limestone containing a significant percentage of magnesium . Most limestone was formed in shallow marine environments, such as continental shelves or platforms , though smaller amounts were formed in many other environments. Much dolomite
1040-435: A limestone sample except in thin section and are less common in ancient limestones, possibly because compaction of carbonate sediments disrupts them. Limeclasts are fragments of existing limestone or partially lithified carbonate sediments. Intraclasts are limeclasts that originate close to where they are deposited in limestone, while extraclasts come from outside the depositional area. Intraclasts include grapestone , which
1120-471: A lower Mg/Ca ratio in the ocean water of those times. This magnesium depletion may be a consequence of more rapid sea floor spreading , which removes magnesium from ocean water. The modern ocean and the ocean of the Mesozoic have been described as "aragonite seas". Most limestone was formed in shallow marine environments, such as continental shelves or platforms . Such environments form only about 5% of
1200-525: A lower diversity of organisms and a greater fraction of silica and clay minerals characteristic of marls . The Green River Formation is an example of a prominent freshwater sedimentary formation containing numerous limestone beds. Freshwater limestone is typically micritic. Fossils of charophyte (stonewort), a form of freshwater green algae, are characteristic of these environments, where the charophytes produce and trap carbonates. Limestones may also form in evaporite depositional environments . Calcite
1280-564: A means to evaluate soil fertility and vigour of the trees. The bark of most pines is thick and scaly, but some species have thin, flaky bark. The branches are produced in "pseudo whorls", actually a very tight spiral but appearing like a ring of branches arising from the same point. Many pines are uninodal, producing just one such whorl of branches each year, from buds at the tip of the year's new shoot , but others are multinodal, producing two or more whorls of branches per year. Pines have four types of leaf : Pines are monoecious , having
1360-523: A mechanism for dolomitization, with one 2004 review paper describing it bluntly as "a myth". Ordinary seawater is capable of converting calcite to dolomite, if the seawater is regularly flushed through the rock, as by the ebb and flow of tides (tidal pumping). Once dolomitization begins, it proceeds rapidly, so that there is very little carbonate rock containing mixed calcite and dolomite. Carbonate rock tends to be either almost all calcite/aragonite or almost all dolomite. About 20% to 25% of sedimentary rock
1440-448: A plausible source of mud. Another possibility is direct precipitation from the water. A phenomenon known as whitings occurs in shallow waters, in which white streaks containing dispersed micrite appear on the surface of the water. It is uncertain whether this is freshly precipitated aragonite or simply material stirred up from the bottom, but there is some evidence that whitings are caused by biological precipitation of aragonite as part of
1520-670: A popular Christmas tree, but the extreme length of the needles (making it very difficult to decorate) soon led to its fall from favor, and it has long since been abandoned in the US for that purpose. P. nigra is planted for windbreaks and shelterbelts in the US, recommended for windbreaks in the Northern Great Plains on medium to deep moist or upland soils. Pine See List of Pinus species for complete taxonomy to species level. See list of pines by region for list of species by geographic distribution . A pine
1600-449: A radial rather than layered internal structure, indicating that they were formed by algae in a normal marine environment. Peloids are structureless grains of microcrystalline carbonate likely produced by a variety of processes. Many are thought to be fecal pellets produced by marine organisms. Others may be produced by endolithic (boring) algae or other microorganisms or through breakdown of mollusc shells. They are difficult to see in
1680-517: A wide range of soil types, Corsican origins grows poorly on limestone , while Turkish and Crimean origins grow well on limestone. Most provenances also show good growth on podzolic soils. Pinus nigra has become naturalised in a few areas of the US. In New Zealand it is considered an invasive species and noxious weed , along with lodgepole pine ( P. contorta ) and Scots pine ( P. sylvestris ), due to their habitat conversion nature in tussock grassland plant communities, shading out
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#17327723831581760-532: A yellow-buff wing 20–25 mm ( 3 ⁄ 4 –1 in) long; they are wind-dispersed when the cones open from December to April. maturity is reached at 15–40 years; large seed crops are produced at 2–5 year intervals. Pinus nigra is moderately fast growing, at about 30–70 cm (12–28 in) per year. It usually has a rounded conic form, that becomes irregular with age. The tree can be long-lived, with some trees over 500 years old. Multiple pests can damage P. nigra , including T. piniperda . The species
1840-430: Is a light-demanding species, intolerant of shade but resistant to wind and drought. The eastern P. nigra subsp. nigra exhibits greater winter frost hardiness (hardy to below −30 °C) than the western P. nigra subsp. salzmannii (hardy to about −25 °C). Different provenances (seed sources by geographic area) or varieties are adapted to different soil types: Austrian and Pyrenees origins grow well on
1920-416: 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 CaCO 3 . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as
2000-560: Is also favored on the seaward margin of shelves and platforms, where there is upwelling deep ocean water rich in nutrients that increase organic productivity. Reefs are common here, but when lacking, ooid shoals are found instead. Finer sediments are deposited close to shore. The lack of deep sea limestones is due in part to rapid subduction of oceanic crust, but is more a result of dissolution of calcium carbonate at depth. The solubility of calcium carbonate increases with pressure and even more with higher concentrations of carbon dioxide, which
2080-482: Is an uncommon mineral in limestone, and siderite or other carbonate minerals are rare. However, the calcite in limestone often contains a few percent of magnesium . Calcite in limestone is divided into low-magnesium and high-magnesium calcite, with the dividing line placed at a composition of 4% magnesium. High-magnesium calcite retains the calcite mineral structure, which is distinct from dolomite. Aragonite does not usually contain significant magnesium. Most limestone
2160-541: Is any conifer tree or shrub in the genus Pinus ( / ˈ p aɪ n ə s / ) of the family Pinaceae . Pinus is the sole genus in the subfamily Pinoideae . World Flora Online accepts 187 species names of pines as current, with additional synonyms, making it the largest family among the conifers. The American Conifer Society (ACS) and the Royal Horticultural Society accept 121 species. The highest species diversity of pines
2240-402: Is carbonate rock, and most of this is limestone. Limestone is found in sedimentary sequences as old as 2.7 billion years. However, the compositions of carbonate rocks show an uneven distribution in time in the geologic record. About 95% of modern carbonates are composed of high-magnesium calcite and aragonite. The aragonite needles in carbonate mud are converted to low-magnesium calcite within
2320-474: Is clusters of peloids cemented together by organic material or mineral cement. Extraclasts are uncommon, are usually accompanied by other clastic sediments, and indicate deposition in a tectonically active area or as part of a turbidity current . The grains of most limestones are embedded in a matrix of carbonate mud. This is typically the largest fraction of an ancient carbonate rock. Mud consisting of individual crystals less than 5 μm (0.20 mils) in length
2400-416: Is commonly white to gray in color. Limestone that is unusually rich in organic matter can be almost black in color, while traces of iron or manganese can give limestone an off-white to yellow to red color. The density of limestone depends on its porosity, which varies from 0.1% for the densest limestone to 40% for chalk. The density correspondingly ranges from 1.5 to 2.7 g/cm . Although relatively soft, with
2480-420: Is controlled largely by the amount of dissolved carbon dioxide ( CO 2 ) in the water. This is summarized in the reaction: Increases in temperature or decreases in pressure tend to reduce the amount of dissolved CO 2 and precipitate CaCO 3 . Reduction in salinity also reduces the solubility of CaCO 3 , by several orders of magnitude for fresh water versus seawater. Near-surface water of
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2560-545: Is converted to low-magnesium calcite. Diagenesis is the likely origin of pisoliths , concentrically layered particles ranging from 1 to 10 mm (0.039 to 0.394 inches) in diameter found in some limestones. Pisoliths superficially resemble ooids but have no nucleus of foreign matter, fit together tightly, and show other signs that they formed after the original deposition of the sediments. Silicification occurs early in diagenesis, at low pH and temperature, and contributes to fossil preservation. Silicification takes place through
2640-503: Is deposited close to where it formed, classification of limestone is usually based on its grain type and mud content. Most grains in limestone are skeletal fragments of marine organisms such as coral or foraminifera . These organisms secrete structures made of aragonite or calcite, and leave these structures behind when they die. Other carbonate grains composing limestones are ooids , peloids , and limeclasts ( intraclasts and extraclasts [ ca ] ). Skeletal grains have
2720-460: Is described as coquinite . Chalk is a soft, earthy, fine-textured limestone composed of the tests of planktonic microorganisms such as foraminifera, while marl is an earthy mixture of carbonates and silicate sediments. Limestone forms when calcite or aragonite precipitate out of water containing dissolved calcium, which can take place through both biological and nonbiological processes. The solubility of calcium carbonate ( CaCO 3 )
2800-617: Is described as micrite . In fresh carbonate mud, micrite is mostly small aragonite needles, which may precipitate directly from seawater, be secreted by algae, or be produced by abrasion of carbonate grains in a high-energy environment. This is converted to calcite within a few million years of deposition. Further recrystallization of micrite produces microspar , with grains from 5 to 15 μm (0.20 to 0.59 mils) in diameter. Limestone often contains larger crystals of calcite, ranging in size from 0.02 to 0.1 mm (0.79 to 3.94 mils), that are described as sparry calcite or sparite . Sparite
2880-462: Is distinguished from micrite by a grain size of over 20 μm (0.79 mils) and because sparite stands out under a hand lens or in thin section as white or transparent crystals. Sparite is distinguished from carbonate grains by its lack of internal structure and its characteristic crystal shapes. Geologists are careful to distinguish between sparite deposited as cement and sparite formed by recrystallization of micrite or carbonate grains. Sparite cement
2960-523: Is divided into two subspecies, each further subdivided into three varieties. Some authorities (e.g. Flora Europaea ) treat several of the varieties at subspecific rank, but this reflects tradition rather than sound taxonomy, as the distinctions between the taxa are small. Pinus nigra is a tree of the Mediterranean forests, woodlands, and scrub biome . The majority of the range is in Turkey. It
3040-802: Is found in Mexico. Pines are widely distributed in the Northern Hemisphere ; they occupy large areas of boreal forest , but are found in many habitats, including the Mediterranean Basin . The timber from pine trees is called "pine"; it is one of the most extensively used types of timber. There are currently 818 named cultivars (or trinomials ) recognized by the ACS. It is a well-known type of Christmas tree . Pine trees are evergreen , coniferous resinous trees (or, rarely, shrubs ) growing 3–80 metres (10–260 feet) tall, with
3120-736: Is found in the higher elevations of the South Apennine mixed montane forests ecoregion in southern Italy and the Tyrrhenian-Adriatic sclerophyllous and mixed forests ecoregion in Sicily. There are remnant populations in the Mediterranean conifer and mixed forests ecoregion, and in the higher Atlas Mountains in Morocco and Algeria. It is found at elevations ranging from sea level to 2,000 m (6,600 ft), most commonly from 250–1,600 m (820–5,250 ft). Several of
3200-489: Is important both as a timber tree and in plantations (primarily Corsican pine subsp.). Recently however, serious problems have occurred with red band needle blight disease, caused by the fungus Dothistroma septosporum , resulting in a major recent decline in forestry planting there. In the United States it is of low importance as a timber species. In regard to Austrian pine, the fungus Dothistroma septosporum
3280-449: Is now restricted to fir ( Abies ) and Douglas-fir ( Pseudotsuga ). Pines are gymnosperms . The genus is divided into two subgenera based on the number of fibrovascular bundles in the needle. The subgenera can be distinguished by cone, seed, and leaf characters: Phylogenetic evidence indicates that both subgenera have a very ancient divergence from one another. Each subgenus is further divided into sections and subsections. Many of
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3360-801: Is one of the world's oldest living organisms at around 4,800 years old. This tree can be found in the White Mountains of California. An older tree, now cut down, was dated at 4,900 years old. It was discovered in a grove beneath Wheeler Peak and it is now known as " Prometheus " after the Greek immortal . The spiral growth of branches, needles, and cones scales are arranged in Fibonacci number ratios. The new spring shoots are sometimes called "candles"; they are covered in brown or whitish bud scales and point upward at first, then later turn green and spread outward. These "candles" offer foresters
3440-560: Is one of the first minerals to precipitate in marine evaporites. Most limestone is formed by the activities of living organisms near reefs, but the organisms responsible for reef formation have changed over geologic time. For example, stromatolites are mound-shaped structures in ancient limestones, interpreted as colonies of cyanobacteria that accumulated carbonate sediments, but stromatolites are rare in younger limestones. Organisms precipitate limestone both directly as part of their skeletons, and indirectly by removing carbon dioxide from
3520-473: Is otherwise chemically fairly pure, with clastic sediments (mainly fine-grained quartz and clay minerals ) making up less than 5% to 10% of the composition. Organic matter typically makes up around 0.2% of a limestone and rarely exceeds 1%. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragments (such as sponge spicules, diatoms , or radiolarians ). Fossils are also common in limestone. Limestone
3600-402: Is planted with great success as far north as Edmonton, Alberta, Canada. In both the US and UK most of the specimens planted are from Austrian sources, the P. nigra subsp. nigra and P. nigra subsp. nigra var. nigra seed selections. In the late 1950s and early 1960s, when demand for natural trees was extremely high, its rapid growth, deep green color and low cost made it briefly
3680-472: Is produced by decaying organic matter settling into the deep ocean that is not removed by photosynthesis in the dark depths. As a result, there is a fairly sharp transition from water saturated with calcium carbonate to water unsaturated with calcium carbonate, the lysocline , which occurs at the calcite compensation depth of 4,000 to 7,000 m (13,000 to 23,000 feet). Below this depth, foraminifera tests and other skeletal particles rapidly dissolve, and
3760-518: Is secondary dolomite, formed by chemical alteration of limestone. Limestone is exposed over large regions of the Earth's surface, and because limestone is slightly soluble in rainwater, these exposures often are eroded to become karst landscapes. Most cave systems are found in limestone bedrock. Limestone has numerous uses: as a chemical feedstock for the production of lime used for cement (an essential component of concrete ), as aggregate for
3840-652: Is the largest genus of the Pinaceae , the pine family, which first appeared in the Jurassic period. Based on recent Transcriptome analysis, Pinus is most closely related to the genus Cathaya , which in turn is closely related to spruces . These genera, with firs and larches , form the pinoid clade of the Pinaceae. Pines first appeared during the Early Cretaceous, with the oldest verified fossil of
3920-480: Is widespread and rapidly spreading out of control throughout the United States. It is out of control and not recommended for landscaping, especially in groups or rows. In Turkey, this pine (subsp. pallasiana) was and is used in various ways, both topically and internally, as well as for construction and for livestock. Among its uses are curing acne , common cold , osteomyelitis , and viral infections ; acting as an oral antiseptic ; treating cracked hands and feet in
4000-496: The Earth's history. Limestone may have been deposited by microorganisms in the Precambrian , prior to 540 million years ago, but inorganic processes were probably more important and likely took place in an ocean more highly oversaturated in calcium carbonate than the modern ocean. Diagenesis is the process in which sediments are compacted and turned into solid rock . During diagenesis of carbonate sediments, significant chemical and textural changes take place. For example, aragonite
4080-665: The Indo-European base *pīt- ‘resin’ (source of English pituitary ). Before the 19th century, pines were often referred to as firs (from Old Norse fura , by way of Middle English firre ). In some European languages, Germanic cognates of the Old Norse name are still in use for pines — in Danish fyr , in Norwegian fura/fure/furu , Swedish fura/furu , Dutch vuren , and German Föhre — but in modern English, fir
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#17327723831584160-430: The accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite , a closely related rock, which contains
4240-434: The base of roads, as white pigment or filler in products such as toothpaste or paint, as a soil conditioner , and as a popular decorative addition to rock gardens . Limestone formations contain about 30% of the world's petroleum reservoirs . Limestone is composed mostly of the minerals calcite and aragonite , which are different crystal forms of calcium carbonate ( CaCO 3 ). Dolomite , CaMg(CO 3 ) 2 ,
4320-657: The beds. This may include the formation of vugs , which are crystal-lined cavities within the limestone. Diagenesis may include conversion of limestone to dolomite by magnesium-rich fluids. There is considerable evidence of replacement of limestone by dolomite, including sharp replacement boundaries that cut across bedding. The process of dolomitization remains an area of active research, but possible mechanisms include exposure to concentrated brines in hot environments ( evaporative reflux ) or exposure to diluted seawater in delta or estuary environments ( Dorag dolomitization ). However, Dorag dolomitization has fallen into disfavor as
4400-985: The country, which is known for a very dry climate, inhospitable for most trees. It has a length of 11 meters, a diameter of 3 meters and a circumference of 9.60 meters. Pinus nigra is a large coniferous evergreen tree , growing to 20–55 metres (66–180 feet) high at maturity and spreading to 6 to 12 m (20 to 39 ft) wide. The bark is gray to yellow-brown, and is widely split by flaking fissures into scaly plates, becoming increasingly fissured with age. The leaves ('needles') are thinner and more flexible in western populations. The ovulate and pollen cones appear from May to June. The mature seed cones are 5–10 centimetres (2–4 inches) (rarely to 11 cm) long, with rounded scales; they ripen from green to pale gray-buff or yellow-buff in September to November, about 18 months after pollination. The seeds are dark gray, 6–8 millimetres ( 1 ⁄ 4 – 5 ⁄ 16 in) long, with
4480-466: The depositional fabric of carbonate rocks. Dunham divides the rocks into four main groups based on relative proportions of coarser clastic particles, based on criteria such as whether the grains were originally in mutual contact, and therefore self-supporting, or whether the rock is characterized by the presence of frame builders and algal mats. Unlike the Folk scheme, Dunham deals with the original porosity of
4560-469: The deposits are highly porous, so that they have a spongelike texture, they are typically described as tufa . Secondary calcite deposited by supersaturated meteoric waters ( groundwater ) in caves is also sometimes described as travertine. This produces speleothems , such as stalagmites and stalactites . Coquina is a poorly consolidated limestone composed of abraded pieces of coral , shells , or other fossil debris. When better consolidated, it
4640-406: The earth's oceans are oversaturated with CaCO 3 by a factor of more than six. The failure of CaCO 3 to rapidly precipitate out of these waters is likely due to interference by dissolved magnesium ions with nucleation of calcite crystals, the necessary first step in precipitation. Precipitation of aragonite may be suppressed by the presence of naturally occurring organic phosphates in
4720-399: The first refers to the grains and the second to the cement. For example, a limestone consisting mainly of ooids, with a crystalline matrix, would be termed an oosparite. It is helpful to have a petrographic microscope when using the Folk scheme, because it is easier to determine the components present in each sample. Robert J. Dunham published his system for limestone in 1962. It focuses on
4800-572: The formation of distinctive minerals from the silica and clay present in the original limestone. Two major classification schemes, the Folk and Dunham, are used for identifying the types of carbonate rocks collectively known as limestone. Robert L. Folk developed a classification system that places primary emphasis on the detailed composition of grains and interstitial material in carbonate rocks . Based on composition, there are three main components: allochems (grains), matrix (mostly micrite), and cement (sparite). The Folk system uses two-part names;
4880-562: The genus being Pinus yorkshirensis from the Hauterivian - Barremian boundary (~130-125 million years ago) from the Speeton Clay , England. The evolutionary history of the genus Pinus has been complicated by hybridization . Pines are prone to inter-specific breeding. Wind pollination, long life spans, overlapping generations, large population size, and weak reproductive isolation make breeding across species more likely. As
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#17327723831584960-429: The geologic record are called bioherms . Many are rich in fossils, but most lack any connected organic framework like that seen in modern reefs. The fossil remains are present as separate fragments embedded in ample mud matrix. Much of the sedimentation shows indications of occurring in the intertidal or supratidal zones, suggesting sediments rapidly fill available accommodation space in the shelf or platform. Deposition
5040-586: The majority of species reaching 15–45 m (50–150 ft) tall. The smallest are Siberian dwarf pine and Potosi pinyon , and the tallest is an 83.45 m (273.8 ft) tall sugar pine located in Yosemite National Park . Pines are long lived and typically reach ages of 100–1,000 years, some even more. The longest-lived is the Great Basin bristlecone pine ( P. longaeva ). One individual of this species, dubbed " Methuselah ",
5120-507: The male and female cones on the same tree. The male cones are small, typically 1–5 cm long, and only present for a short period (usually in spring, though autumn in a few pines), falling as soon as they have shed their pollen . The female cones take 1.5–3 years (depending on species) to mature after pollination , with actual fertilization delayed one year. At maturity the female cones are 3–60 cm long. Each cone has numerous spirally arranged scales, with two seeds on each fertile scale;
5200-490: The native bunch grasses as their forest canopy develops. The timber of European black pine is similar to that of Scots pine ( P. sylvestris ) and red pine ( P. resinosa ), being moderately hard and straight-grained. It does however tend to be rougher, softer, and not as strong, due to its faster growth. It is used for general construction, fuel, and in paper manufacture. In the United Kingdom, Pinus nigra
5280-410: The ocean basins, but limestone is rarely preserved in continental slope and deep sea environments. The best environments for deposition are warm waters, which have both a high organic productivity and increased saturation of calcium carbonate due to lower concentrations of dissolved carbon dioxide. Modern limestone deposits are almost always in areas with very little silica-rich sedimentation, reflected in
5360-799: The pines have diversified, gene transfer between different species has created a complex history of genetic relatedness. P. nelsonii P. aristata P. balfouriana P. longaeva P. pinceana P. maximartinezii P. rzedowskii P. quadrifolia P. monophylla P. culminicola P. discolor P. remota P. edulis P. cembroides P. bungeana P. squamata P. gerardiana P. krempfii P. peuce P. lambertiana P. strobus P. chiapensis P. monticola P. flexilis P. strobiformis P. ayacahuite P. albicaulis P. koraiensis P. sibirica P. cembra P. parviflora P. wallichiana Limestone Limestone ( calcium carbonate CaCO 3 )
5440-426: The reaction: Fossils are often preserved in exquisite detail as chert. Cementing takes place rapidly in carbonate sediments, typically within less than a million years of deposition. Some cementing occurs while the sediments are still under water, forming hardgrounds . Cementing accelerates after the retreat of the sea from the depositional environment, as rainwater infiltrates the sediment beds, often within just
5520-482: The relative purity of most limestones. Reef organisms are destroyed by muddy, brackish river water, and carbonate grains are ground down by much harder silicate grains. Unlike clastic sedimentary rock, limestone is produced almost entirely from sediments originating at or near the place of deposition. Limestone formations tend to show abrupt changes in thickness. Large moundlike features in a limestone formation are interpreted as ancient reefs , which when they appear in
5600-460: The rock. The Dunham scheme is more useful for hand samples because it is based on texture, not the grains in the sample. A revised classification was proposed by Wright (1992). It adds some diagenetic patterns to the classification scheme. Travertine is a term applied to calcium carbonate deposits formed in freshwater environments, particularly waterfalls , cascades and hot springs . Such deposits are typically massive, dense, and banded. When
5680-453: The scales at the base and tip of the cone are small and sterile, without seeds. The seeds are mostly small and winged, and are anemophilous (wind-dispersed), but some are larger and have only a vestigial wing, and are bird -dispersed. Female cones are woody and sometimes armed to protect developing seeds from foragers. At maturity, the cones usually open to release the seeds. In some of the bird-dispersed species, for example whitebark pine ,
5760-479: The sediments increases. Chemical compaction takes place by pressure solution of the sediments. This process dissolves minerals from points of contact between grains and redeposits it in pore space, reducing the porosity of the limestone from an initial high value of 40% to 80% to less than 10%. Pressure solution produces distinctive stylolites , irregular surfaces within the limestone at which silica-rich sediments accumulate. These may reflect dissolution and loss of
5840-662: The sediments of the ocean floor abruptly transition from carbonate ooze rich in foraminifera and coccolith remains ( Globigerina ooze) to silicic mud lacking carbonates. In rare cases, turbidites or other silica-rich sediments bury and preserve benthic (deep ocean) carbonate deposits. Ancient benthic limestones are microcrystalline and are identified by their tectonic setting. Fossils typically are foraminifera and coccoliths. No pre-Jurassic benthic limestones are known, probably because carbonate-shelled plankton had not yet evolved. Limestones also form in freshwater environments. These limestones are not unlike marine limestone, but have
5920-469: The seeds are only released by the bird breaking the cones open. In others, the seeds are stored in closed cones for many years until an environmental cue triggers the cones to open, releasing the seeds. This is called serotiny . The most common form of serotiny is pyriscence, in which a resin binds the cones shut until melted by a forest fire, for example in P. rigida . The modern English name "pine" derives from Latin pinus , which some have traced to
6000-422: The smaller groups of Pinus are composed of closely related species with recent divergence and history of hybridization. This results in low morphological and genetic differences. This, coupled with low sampling and underdeveloped genetic techniques, has made taxonomy difficult to determine. Recent research using large genetic datasets has clarified these relationships into the groupings we recognize today. Pinus
6080-816: The varieties have distinct English names. It needs full sun to grow well, is intolerant of shade , and is resistant to snow and ice damage. It has naturalized in parts of the midwestern states of the United States, normally south of the normal native ranges of native pines. In Mediterranean Europe and the Anatolian Peninsula ( Asia Minor ), trees usually associated with this species include Scots pine ( Pinus sylvestris ), Serbian spruce ( Picea omorika ), Bosnian pine ( Pinus heldreichii ), Norway spruce ( Picea abies ), Taurus cedar ( Cedrus libani ), European silver fir ( Abies alba ) and related firs . Several species of juniper ( Juniperus spp.), and various broadleaf trees are associates. Pinus nigra
6160-533: The water by photosynthesis and thereby decreasing the solubility of calcium carbonate. Limestone shows the same range of sedimentary structures found in other sedimentary rocks. However, finer structures, such as lamination , are often destroyed by the burrowing activities of organisms ( bioturbation ). Fine lamination is characteristic of limestone formed in playa lakes , which lack the burrowing organisms. Limestones also show distinctive features such as geopetal structures , which form when curved shells settle to
6240-553: The water. Although ooids likely form through purely inorganic processes, the bulk of CaCO 3 precipitation in the oceans is the result of biological activity. Much of this takes place on carbonate platforms . The origin of carbonate mud, and the processes by which it is converted to micrite, continue to be a subject of research. Modern carbonate mud is composed mostly of aragonite needles around 5 μm (0.20 mils) in length. Needles of this shape and composition are produced by calcareous algae such as Penicillus , making this
6320-541: The winter; and sealing wooden roofs. In the US and Canada, the European black pine is planted as a street tree, and as an ornamental tree in gardens and parks. Its value as a street tree is largely due to its resistance to salt spray (from road de-icing salt) and various industrial pollutants (including ozone ), and its intermediate drought tolerance. In the UK the tree is planted as an ornamental tree in parks and gardens. It
6400-416: Was likely deposited in pore space between grains, suggesting a high-energy depositional environment that removed carbonate mud. Recrystallized sparite is not diagnostic of depositional environment. Limestone outcrops are recognized in the field by their softness (calcite and aragonite both have a Mohs hardness of less than 4, well below common silicate minerals) and because limestone bubbles vigorously when
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