Carbonate rock: description, features, composition and classification

Education

On Earth there is a huge number of differentrocks. Some of them have similar signs, therefore they are united in large groups. For example, one of them is carbonate rocks. About their examples and classifications read in the article.

Classification by origin

Carbonate rocks were formed in different ways. There are four ways of forming this type of rock.

From chemical sediments. Thus there were dolomites and marls, limestones and siderite.
From organogenic precipitation formed such rocks as algal and coral limestones.
From the wreckage formed sandstones and conglomerates.
Recrystallized rocks - these are some types of dolomite and marble.

Structure of carbonate rocks

One of the most important parameters by whichselect the necessary for production and processing of rocks, is their structure. The most important aspect of the structure of carbonate rocks is their granularity. This parameter divides the rocks into several types:

Coarse-grained.
Coarse-grained.
Medium-grained.
Fine-grained.
Fine-grained.

Properties

Due to the fact that there is a large number ofrocks of carbonate type, each of them has its own properties, for which it is very valued in production and industry. What physical and chemical properties of carbonate rocks are known to people?

Good solubility in acids. Limestones dissolve in the cold state, and magnesite and siderite - only when heated. However, the result is similar.
High frost resistance and good fire resistance - undoubtedly, the most important qualities of many carbonate rocks.

Limestone rocks

Any carbonate rock consists of mineralscalcite, magnesite, siderite, dolomite, as well as various impurities. Because of the differences in composition, this large group of rocks is divided into three smaller ones. One of them is limestone.

Their main component is calcite, and inDepending on the impurities they are divided into sandy, clayey, siliceous and others. They have different textures. The fact is that on the cracks of their layers you can see the ripples and rain drops, salt crystals that are soluble, and also microscopic cracks. Limestones can be different in color. The dominant color is beige, grayish or yellowish, and the impurities have a pink, greenish or brownish tinge.

The most common limestone rocks are the following:

a piece of chalk - very soft breed which easily pounded. It can be broken by hand or grind into powder. It is considered a type of cemented limestone. Chalk is an invaluable raw material used in the production of cement building material.
Lime tuffs - porous loose rock. It is quite easily developed. The shell rocks have almost the same meaning.

Dolomite rocks

Dolomitic rocks are mineral contentdolomite in which is more than 50%. Often they contain impurities of calcite. Because of this, you can observe some similarities and differences between the two groups of rocks: the actual dolomite and limestone.

Dolomites differ from limestone in thathave a more pronounced brilliance. They are less soluble in acids. Even organic residues are much less common in them. The color of dolomites is represented by greenish, pinkish, brownish and yellowish shades.

Which dolomite rocks are more commonTotal? This, in the first place, will throw - a denser stone. In addition, there is a graynerite pale pink color, it is widely used in interior design. Teruelite is also a type of dolomite. This stone is remarkable in that it is found only in black in nature, while the rest of the rocks of this group are painted in light shades.

Carbonate-clay rocks, or marls

The composition of carbonate rocks of this type includesa lot of clay, namely, almost 20 percent. By itself, the breed with the same name has a mixed composition. Aluminosilicates (clay products of feldspar disintegration), as well as calcium carbonate in any form, are necessarily present in its structure. Carbonate-clay rocks are a transitional link between limestone and clay. Margel can have various structures, dense or solid, sallow or loose. Most often they occur in the form of several layers, each of which is characterized by a certain composition.

High-quality carbonate rock of this typeused in the production of rubble. Marl, which contains admixtures of gypsum, is of no value, therefore this variety is almost not mined. If you compare this type of rocks with others, then most of all it looks like shale and aleurolite.

Limestone

Any classification of carbonate rocks containsa group called "limestone". The stone that gave it its name has been widely used in various industries. Limestone is the most popular rock in its group. It has a number of positive qualities, thanks to which it has become widespread.

There is limestone of different colors. It all depends on how much iron contains in the rock, because these compounds paint limestone in many tones. Most often it is brown, yellow and red shades. Limestone - the stone is quite dense, it lies underground in the form of huge layers. Sometimes whole mountains are formed, the basic component of which is a given rock. You can see the layers described above near the rivers with steep banks. Here you can see them very well.

Limestone has a number of properties thatdistinguish it from other rocks. To distinguish them is very easy. The easiest way to do at home is to drop a little vinegar on it, just a few drops. Then a hissing sound is heard and gas begins to emit. Other breeds do not have such a reaction to acetic acid.

Using

Each carbonate rock has found application inany area of industry. Thus, limestones along with dolomites and magnesites are used in metallurgy as fluxes. These are substances that are used in the smelting of metals from ore. With their help, the melting point of ores is reduced, which makes it easier to separate metals from waste rock.

Such a carbonate rock, like chalk, is familiar to everyone.teachers and students, because with its help they write on the blackboard. In addition, chalked white walls. It is also used to make a powder for brushing your teeth, however, at present this paste is difficult to get.

Limestone is used to produce soda, nitrogenousfertilizers, as well as calcium carbide. Carbonate rock of any of the presented types, for example, limestone, is used in the construction of residential, industrial premises and roads. It is widely used as a facing material and aggregate concrete. It is also used to obtain feed additives with minerals and to saturate the soil with limestone. From it create building stones, for example, rubble and rubble. In addition, cement and lime are produced from this rock, which are widely used in many types of industry, for example, in metallurgical and chemical industries.

Collectors

There is a variety of rocks likecollectors. They have the ability that allows them to contain water, gas, oil, and turn for some time to give them back when developing. Why it happens? The fact is that a number of rocks have a porous structure and this quality is very much appreciated. It is due to the porosity, they can accommodate a large amount of oil and gas.

Carbonate rocks - high quality reservoirs. Dolomites, limestones and chalk are the best in their group. 42 percent of oil reservoirs used and 23 percent of gas reservoirs are carbonate. These rocks occupy the second place after terrigenous.