what does cementation mean in science

Scientific definitions for cementation cementation [ sē′mĕn-tā ′shən ] A metallurgical coating process in which a metal or alloy such as iron or steel is immersed in a powder of another metal, such as zinc, chromium

, or aluminum, and heated to a temperature below the melting point of either.

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What happens during the process of cementation?

What happens during the process of cementation? Cementation involves ions carried in groundwater chemically precipitating to form new crystalline material between sedimentary grains. Cementation occurs in fissures or other openings of existing rocks and is a dynamic process more or less in equilibrium with a dissolution or dissolving process .

What are some examples of cementation?

Cementation examples include beachrock and carbonate hardground. Beachrock is a type of rock that forms along the shore and is made of a huge range of sediment types and sizes cemented together.

How to pronounce cementation?

Pronunciation of Cemech cement with and more for Cemech cement. Dictionary Collections Quiz Community Contribute Certificate

What change is caused by cementation?

Whether rock melts to create magma depends on:

• Temperature: Temperature increases with depth, so melting is more likely to occur at greater depths.
• Pressure: Pressure increases with depth, but increased pressure raises the melting temperature, so melting is less likely to occur at higher pressures.
• Water: The addition of water changes the melting point of rock. ...

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What is cementation in science terms?

Definition of cementation 1 : a process of surrounding a solid with a powder and heating the whole so that the solid is changed by chemical combination with the powder. 2 : the act or process of cementing : the state of being cemented.

What does cementation mean for kids?

Cementation... compaction. in geology, decrease of the volume of a fixed mass of sediment from any cause, commonly from continual sediment deposition at a particular site. Other causes include wetting... sedimentary rock.

What is an example of cementation in rocks?

Cementation examples include beachrock and carbonate hardground. Beachrock is a type of rock that forms along the shore and is made of a huge range of sediment types and sizes cemented together. Sediment can include rocks and sand, and also shells and coral. Hardground is cemented seafloor.

What does compaction and cementation mean?

1. Compaction occurs when the overlying sediments' weight compacts the grains as tightly as possible. 2. Cementation is the process whereby dissolved minerals in the water between the grains crystallize cementing the grains together.

How do you use cementation in a sentence?

Cementation sentence example The conversion of the silver into the chloride may be effected by means of salt - the " cementation " process - or other chlorides, or by free chlorine - Miller's process. Oil filled the crest of the reservoir first and prevented extensive quartz cementation .

What do you mean by cementation Class 12?

Cementation process is the hardening of cement during the process of construction. The process starts after adding water to the mixture of cement, sand and small stone pieces. In this, a gel type of product is formed which gets thickened and hardened gradually. So cementation is the process of gel formation.

What holds rocks together?

The material that holds sediment together into a rock is called cement. Cement is mineral that forms when seawater or groundwater travels through the empty spaces between sediment. If the water contains the chemicals that are needed, mineral crystals will form in-between the sediment.

How do rocks cement together?

This process is called compaction. At the same time the particles of sediment begin to stick to each other - they are cemented together by clay, or by minerals like silica or calcite. After compaction and cementation the sedimentary sequence has changed into a sedimentary rock.

Does cementation involve water?

Cementation occurs primarily below the water table regardless of sedimentary grain sizes present. Large volumes of pore water must pass through sediment pores for new mineral cements to crystallize and so millions of years are generally required to complete the cementation process.

What is cementation and deposition?

As more and more sediments are deposited the weight on the sediments below increases. Waterborne sediments become so tightly squeezed together that most of the water is pushed out. Cementation happens as dissolved minerals become deposited in the spaces between the sediments.

What does compacting mean in science?

happens when sediments are deeply buried, placing them under pressure because of the weight of overlying layers. This squashes the grains together more tightly.

How are sedimentary rocks cemented together?

Dissolved minerals in the ground water precipitate (crystallize) from water in the pore spaces forming mineral crusts on the sedimentary grains, gradually cementing the sediments, thus forming a rock. Calcite (calcium carbonate), silica, and hematite (red iron oxide) are the most common cementing agents.

What does "cement" mean?

noun. the act, process, or result of cementing. Metallurgy. the heating of two substances in contact in order to effect some change in one of them, especially, the formation of steel by heating iron in powdered charcoal. QUIZ.

What happens if cementation is continued too long?

If the cementation be continued too long, the steel acquires a darkish fracture, it is more fusible, and incapable of welding.

What is the process of coating a metal?

A metallurgical coating process in which a metal or alloy such as iron or steel is immersed in a powder of another metal, such as zinc, chromium, or aluminum, and heated to a temperature below the melting point of either. Cementation is often employed to increase resistance to oxidation.

Why is the word "sinister" Latin?

The word "sinister" is Latin for "left," because left-handed people were often thought of as suspicious, evil, or demonic.

Why is cementation used?

Cementation is commonly used because of its low cost and adaptability to wet wastes. Besides, because the process could be conducted on-site, the transport costs and secondary emissions are largely minimized (Ma and Garbers-Craig, 2006 ). Since 1989, the super-detoxification process has been commercialized by Bethlehem Steel Corporation to mix electric furnace dust with lime and alumina-silicates as well as other additives to make a concrete-like material that can efficiently immobilize heavy metals in the matrix by precipitating or oxidizing/reducing heavy metals into the least soluble components (Zunkel, 1997 ).

When was zinc cementation first used?

The use of the zinc cementation process for gold recovery was first patented in Great Britain by J. MacArthur and Drs. R. and W. Forrest in 1888 . Initial applications were at the Crown mine in New Zealand and Robinson Deep in South Africa during the 2 years following patenting. It soon became the preferred gold recovery step and an integral part of the cyanidation process. The first application in the United States was by C.W. Merrill at the Homestake mine in Lead, South Dakota.

How does carbonate cement work?

Carbonate cements develop around the contacts between thick sand and mudstone intervals. On the one hand, this stops large-scaled carbonate cementation in middle sand. On the other hand, abnormally high formation pressure could be preserved, and to some extent the anticompression capability is enhanced. Although the tight cements, for which the shortest distance from thick sand to mudstone is less than 0.5 m, damage the reservoir space at the margin of sand, they can protect the primary intergranular pores in the reservoir, whose shortest distance to mudstone is more than 0.5 m, facilitating it to form a good reservoir.

What is the process of sandstone turning into sandstone?

Cementation is the most important diagenetic process by which loose, scattered sand converts into tightly bound rock sandstone.

How does mechanical compaction occur in carbonate sands?

In carbonate sands, most of the mechanical compaction occurs at low stress, i.e. less than 5 MPa. When a locked state is reached, compaction proceeds by grain crushing with lower strain rates. Compaction of carbonate sands depends on the initial packing, the sand composition and the grain size, with finer grain-sized samples being less compressible. The shear modulus and the yield strength both increase with cementation. Rocks tested in the laboratory show a non-linear stress-strain relationship which can be related to the amount of pre-existing cracks and various types of pores present ( Baud et al., 2000 ). Porosity seems to be the main controlling factor on rock compressibility. Overall, carbonate rocks are less compressible than sandstones ( Wong et al., 2004 ). Understanding mechanical compaction and the determination of rocks elastic moduli is important. However, these parameters are affected by chemical compaction processes that alter the grain-to-grain contacts and modify the grain or rock framework stiffness. Moreover, experimental mechanical compaction shows that mechanical compaction alone usually cannot explain porosity values observed in nature.

Does cement reduce porosity?

Cementation reduces the porosity and permeability of a sand. In some cases, however, solution of cement or grains can reverse this trend. Schmidt et al. (1977) have outlined the petrographic criteria for the recognition of secondary solution porosity in sands. It generally involves the leaching of carbonate cements and grains, including calcite, dolomite, siderite, shell debris, and unstable detrital minerals, especially feldspar. Leached porosity in sands is generally associated with kaolin, which both replaces feldspar and occurs as an authigenic cement.

Is cementation by silica a diagenesis?

Berner (1971, p. 97) states that “cementation by silica must be predominantly a phenomenon of later diagenesis because almost no examples are found in recent marine sediments .”. In contrast, cementation by calcium carbonate may occur rapidly after deposition. A good example is beachrock, a mix of beach and intertidal sand ...

Examples of cementation in a Sentence

Recent Examples on the Web The Iraq deal comes less than a month after Weatherford landed a five-year deal to provide cementation, completions, liners, solid expandables and casing exit services to Saudi Aramco. — Sergio Chapa, Houston Chronicle, 8 Oct.

Medical Definition of cementation

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What is cementation in geology?

Cementation, in geology, hardening and welding of clastic sediments (those formed from preexisting rock fragments) by the precipitation of mineral matter in the pore spaces. It is the last stage in the formation of a sedimentary rock. The cement forms an integral and important part of the rock, and its precipitation affects ...

What is the process of cementation?

Cementation is one of the main processes involved, particularly for sandstones and conglomerates. In addition, reactions take place within a sediment between various minerals and between minerals and the fluids trapped in the pores; these reactions, collectively termed authigenesis, may form new minerals or add….

How does rock form?

…rock may form by carbonate cementation of grains in deposits lying between tide levels. It then acts as a stabilizing factor. Storm waves may drive forward coral fragments derived from staghorn corals growing on the windward slopes of the reef, forming shingle banks; successive superposed banks may thus be formed.…

What is the encyclopaedia Britannica?

Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Cementation, in geology, hardening and welding of clastic sediments (those formed from preexisting rock fragments) by the precipitation ...

What minerals are used to make cement?

Many minerals may become cements; the most common is silica (generally quartz), but calcite and other carbonates also undergo the process, as well as iron oxides, barite, anhydrite, zeolites, and clay minerals. It is unclear just how and when the cement is deposited.

What is the reverse process of calcareous sandstone?

The reverse process is called dissolution. There is evidence that dis solution has occurred in calcareous sandstones, in which case the calcareous cement or grains are broken down in the same manner as the solution of limestones.

What is the purpose of cement joining bones?

The use of a cement join the parts of a broken bone to aid in the healing process

What is the process of fusion?

a process which consists in surrounding a solid body with the powder of other substances, and heating the whole to a degree not sufficient to cause fusion, the physical properties of the body being changed by chemical combination with powder; thus iron becomes steel by cementation with charcoal, and green glass becomes porcelain by cementation with sand

Where does cementation occur?

Cementation occurs in fissures or other openings of existing rocks and is a dynamic process more or less in equilibrium with a dissolution or dissolving process. Cement found on the sea floor is commonly aragonite and can take different textural forms.

What are the phases of cement?

Common mineral cements include calcite, quartz, and silica phases like cristobalite, iron oxides, and clay minerals; other mineral cements also occur. Cementation is continuous in the groundwater zone, so much so that the term "zone of cementation" is sometimes used interchangeably.

What organisms make carbonate cement?

Carbonate cements can also be formed by biological organisms such as Sporosarcina pasteurii, which binds sand together given organic compounds and a calcium source (Chou et al., 2010).

What are the cements found in phreatic zones?

Cements that are found in phreatic zones include: isopachous, blocky, and syntaxial rim cements. As for calcite cementation, which occurs in meteoric realms (freshwater sources), the cement is produced by the dissolution of less stable aragonite and high-Mg calcite. (Boggs, 2011)

What is cementation in sedimentary rock?

The definition of cementation is a process where sediment is chemically glued together when minerals precipitate from the water they are dissolved in and fill the pore space between compressed sediment. Water is very rarely pure hydrogen dioxide; most water is what's called a homogeneous mixture, which is a mixture of water and other minerals evenly distributed throughout. This is where the term "hard water" comes from. Hard water is water with certain quantities of minerals mixed into it. Around a home faucet, if there is white or yellowish powder or crust around the water spouts, chances are that the water connected to that home is hard water and the powder or crust is calcium, silica, and/or magnesium. As water flows over the surface of the Earth, it picks up these minerals and becomes supersaturated, which means there are too many minerals in a certain amount of water. This is true for the water in areas where sedimentary rock forms. Minerals in the supersaturated water are precipitated out and become the cement that holds sedimentary rock together. Minerals that form cement include silica, calcite, and other carbonates as well as some clay minerals.

What are some examples of cementation?

There are many examples of cementation in geology. Cementation examples include beachrock and carbonate hardground. Beachrock is a type of rock that forms along the shore and is made of a huge range of sediment types and sizes cemented together. Sediment can include rocks and sand, and also shells and coral. Hardground is cemented seafloor. In both of these examples, sediment has been cemented together by minerals that have leached out of supersaturated water and welded the sediment together.

What Is Compaction?

Compaction comes before cementation, and it is the process by which sedimentary rocks are buried under other sediment and are then pushed together. Think of layers of play dough that are placed on top of one another. If enough layers are added, it becomes difficult to pull the layers apart because the weight of all the dough is enough to squeeze the layers together. This process, as stated above, happens in lakes or oceans, which are both areas that see a lot of deposition of sediment due to their low elevation levels and exposure to sediment that washes down with the rain. Even though the sediment is compressed together, the individual sediment grains are still solid, which means that there are tiny pockets of air in between each individual sediment grain. This also means that no chemical transformation has happened; the sediment is simply smooshed together.

What is the process of a rock turning into a stone called?

Cementation is the process where minerals from supersaturated water precipitate from, or come out of, the water and cement in the pore spaces between compacted sediment, often on the lake or ocean floor. Lithification is the process of something turning to stone.

What are the last two stages of the sedimentary rock cycle?

Cementation and compaction are the last two stages of the sedimentary rock cycle. Compaction is when deposited sediments are smooshed together by the weight of water and other sediment that has settled on top of it. Cementation is when the sediments are glued together by the minerals that come out of supersaturated water.

What are the stages of sedimentary rock formation?

The sedimentary rock cycle describes how sedimentary rock forms and happens in the following order: erosion, deposition , compaction, cementation. Erosion is when little pieces of bigger rocks break off in a process known as weathering. Deposition is when the broken-off sediment pieces deposit in areas of lower elevation, usually in lakes and oceans. It is in these areas where compaction takes place. Compaction is when sediment is pushed together by the weight of water and other sediment pushing down on it. Cementation is the last stage in the cycle and happens when sediment is glued together by minerals such as silica and calcium carbonate as the minerals infiltrate pore space between compacted sediment. The water that holds the minerals is called a homogeneous mixture because the minerals are evenly distributed among the water. This water becomes supersaturated when it can hold no more minerals, and thus the minerals come out of the water. This process is also called lithification, the process where objects turn to stone. Examples of cementation, along with all kinds of sedimentary rock, include beachrock and hardground, which are both types of cemented seafloor. Grain size is how sedimentary rock is categorized. Shale is an example of sedimentary rock and has the smallest size grains, no more than 1/256 mm large.

What are the two processes that make sedimentary rocks?

Cementation and compaction are both processes involved in lithification, which is the process of sediment turning to stone. This process produces all different kinds of sedimentary rocks. Sedimentary rocks are classified according to the size of their grains. Shale, siltstone, sandstone, and conglomerate are all types of sedimentary rock. Shale is a sedimentary rock that forms from the smallest particles of clay about 1/256 mm large. Though it may not look like it, shale actually forms in very thin layers and can sometimes hold oil in the form of kerogen. Shale also often forms around fossils.