What does the mineral part of the soil consist of: origin and formation, characteristics

In order to successfully grow various crops, you need to have a good understanding of the composition of the soil and understand what the mineral part of the soil is formed and consists of. It is composed of particles of various sizes and has a different composition, which provides a variety of soil types on the planet. Dozens of factors influence its formation, including those related to human activity.

Origin and composition of the mineral part of the soil

The mineral component of the soil was formed during the weathering of rocks and minerals located in the upper layer of the lithosphere.

Metamorphosis also has a serious impact on the mineral composition of the soil, that is, the transformation of some components into others as a result of the influence of the following factors:

1. Physical.
2. Chemical.
3. Biogenic, that is, associated with the activities of wildlife, including microorganisms and flora.

The mineral composition of the soil is the more different from the original rock and minerals, the longer it exists. The mineral part reaches 55-60% of the soil volume and makes up 90-97% of its mass. This means that it is this component that plays a major role in the quality and suitability of soils for growing cultivated plants.

Processes of formation of minerals and rocks

The main processes of formation of minerals and rocks are divided into two types:

1. Deep (endogenous), occurring in the depths of the planet and powered by the energy of its core. These processes form the primary minerals and base rocks (mostly of the crystalline type). They are divided into igneous and metamorphic.
2. Surface (exogenous), occurring on the surface under the influence of solar energy. In this way, the bulk of secondary minerals and sedimentary rocks are formed.

Magmatic processes are characterized by high pressure and temperature. Magma rises from the depths of the Earth, crystallizes and leads to the formation of igneous rocks.

There are several variants of magmatic processes, but the essence of all of them is the rise of molten magma and the formation of base rocks from it. After that, other processes come into play related to pressure, temperature, the movement of layers and their mixing, as well as the influence of hot water flows heated by the volcanic activity of the planet.Passing through different rocks, water washes out components from them, forms s alts and transfers them to close or long distances, giving life to new minerals.

Biogenic processes of mineral formation

These processes of formation of minerals are associated with the vital activity of biological organisms. Dozens of living beings form mineral-based skeletons or deposit minerals in tissues. In this way, calcite crystals are formed, native sulfur that occurs in colonies of blue-green algae near thermal springs and geysers, some silica derivatives - chalcedony and opals, as well as mother-of-pearl and a gem of biological origin - pearls.

Some varieties of river and sea mollusks can produce ultra-thin layers of aragonite interspersed with equally transparent layers of biological matter. Hundreds and thousands of layers form mother-of-pearl overflows due to the penetration of light into a complex structure.

After the death of organisms, their mineral remains accumulate for millions of years at the bottom of reservoirs, compressed, turning into biogenic-sedimentary rocks such as shell rock, limestone, diatomites, and so on.

The decomposition of dying aquatic plants leads to the formation of hydrogen sulfide, which rises to the upper layers of the reservoir, combines with oxygen and oxidizes to sulfates. When sulfates react with s alts dissolved in water, native sulfur and sulfuric acid are deposited. In turn, the acid combines with the calcium in the water and causes gypsum to form.

Sulfur deposits are also formed by anaerobic bacteria that live outside water bodies in continental gypsum deposits. Due to the activity of living organisms, the carbon content in soils is 20 times greater than in the earth's crust, and the amount of nitrogen - more than 10 times. The natural process of soil formation is extremely slow, but human agricultural activities and land improvement accelerate its formation, enrich it and change its composition.

Metamorphic processes of mineral formation

They are associated with the rebirth of previously formed mineralogical components of exogenous and endogenous origin under the influence of changed physical and chemical conditions. The main role in the change of old and the emergence of new minerals is played by pressure, as well as changes in temperature.

Such impacts take impressive time spans, measured not in thousands, but in millions and even billions of years. However, the specificity of metamorphism lies in the fact that, along with a long-term influence, momentary processes, from the point of view of history and mineralogy, can also affect the state of minerals.

The following types of metamorphism exist:

1. Autometamorphism.
2. Dynamometamorphism.
3. Contact.
4. Regional.

Metamorphism at high temperatures and pressure most often does not cause melting, but it can change the chemical composition of the original "raw material" and its physical characteristics, as well as the shape of future mineral deposits. This action ensures the diversity of minerals on the planet and leads to the formation of mineral deposits.

Rock formation

By origin, rocks are divided into the following:

1. Magmatic - can be effusive, that is, formed by magma frozen on the surface, or intrusive, that is, frozen and crystallized inside the earth's crust and mantle. They are the basis of the lithosphere, occupying up to 95% of its total mass. In the role of soil-forming, they manifest themselves weakly, mainly lying in mountainous areas. Depending on the ratio of minerals, they can be acidic, with a high percentage of silica, and basic (neutral and alkaline).Acidic - loose, contains gravel, rich in potassium, but due to their pH level, they are of low nutritional value for plants. The main ones contain a lot of bases and humus, they are distinguished by a dark color and high fertility.
2. Metamorphic - formed as a result of the rebirth of already existing minerals.
3. Sedimentary - are the product of weathering and destruction of other rocks, precipitation from water, the vital activity of biological organisms.

Thus, many and varied forces are involved in the formation of rocks.

Classification, distribution and basic characteristics of soil-forming rocks

Parent, or soil-forming, rocks are weathered loose rocks. In the process of further soil formation, they become the basis for different types of soil.

The main factor in the formation of parent rocks is weathering. All rocks are destroyed at different speeds and intensity, due to which they have different characteristics and properties.

Soil-forming rocks:

1. Eluvium.
2. Eolian deposits.
3. Lessy.
4. Deluvial deposits.
5. Proluvial deposits.
6. Alluvial deposits.
7. Lacustrine deposits.
8. Offshore coastal sediments.
9. Glacial deposits.
10. Fluvioglacial deposits.
11. Ribbon clays.
12. Integumentary loam.
13. Loess-like loam.

Depending on origin, they are divided into:

1. Sedimentary, formed at the bottom of water bodies - fresh and s alty.
2. Detrital, resulting from physical and chemical weathering.
3. Metamorphic, based on the substance of the Earth's mantle.

Parent rocks largely determine the chemical, mineralogical, mechanical composition, fertility and physical characteristics of soils. The distribution and quality of modern soils are directly related to what minerals are under them.

Laying sediments in places of ancient reservoirs provide nutritious fertile or sandy soils, places where collapsing components were washed away from nearby hills, are characterized by thick layers of soil.

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