What is the soil-forming rocks

Soil is a natural body that was formed by the combined influence of animals and plant organisms, relief features, climatic conditions and industrial activity of man on the upper part of the earth's crust. In nature and human life, soil is of great importance. Primarily it serves as a condition for the existence of plants and animals, again - without it, a person would simply die of hunger. Thus, the soil, being the product of life, is also a condition for the existence and development of life on our planet.

Soil is the primary means of production in agriculture. All agricultural activities of man are based on the use of this resource. Crop planting uses this cover as a medium for the development of plants, in animal husbandry - as a basis for the production of livestock food. For farmers, it serves as the object of application of forces.

The entire agricultural industry is somehow tied to the use of the upper layer of the earth's crust. That is why for its expedient use it is necessary to have at least basic knowledge about the properties, composition, formation and distribution of soils.

Soil formation

The process is complex: the parent breed is transformed into a substance that is significantly different from the original, not only by external characteristics, but also by its properties. The basic conditions for successful soil formation are the settlement of living organisms on the parent rock. For the productive reproduction of these organisms, moisture and the kind of nutrition that is available to this form of life is necessary. Both these important components appear as a result of weathering of the rock. Soil formation is a continuous process, depending on the interaction of the original rock with the organisms that have sheltered on it. It proceeds as follows.

The roots of plants that have settled on the rock, absorb useful substances from it, causing them to rise closer to the surface. After the plant dies, the nutrients contained in them go into a mobile state. During this process, some of the substances are washed down by streams of atmospheric precipitation, another part settles in the upper layers of the rock, the third is absorbed by new plants.

Decomposing, plants form humus - complex compounds of organic elements. This humus, accumulating in the upper layers of the rock, gives it new properties and colors it in a darker color. In parallel with the formation of humus, the process of its decomposition proceeds.

The formation and destruction of humus, as well as the accumulation of nutrients in the upper layers of the soil, is called the biological cycle of substances - the essence of the process of soil formation. It is to this cycle that a barren breed becomes fertile.

Modern science divides the main soil-forming rocks into genesis into several categories. Each of them should be considered separately.

Glacial deposits

Soil-forming rocks of this type include various moraines-the main ones, which were deposited in the places where the glacier was earlier, the final ones formed at the very edge of the glacier, and the lateral ones located at the sides of the tongue in the valley type of glaciation.

Whatever form the moraines belong to, they will be boulder deposits: sandy loam, sand, clay and loam - in short, those in the total mass of which contain boulders in varying amounts. Friability and a greater number of them are found most often in marginal moraines, clayeyness is characteristic of the main one.

Glacial deposits form special reliefs, especially in the case of drumlin, the terminal sea and others.

Fluvioglacial deposits

These soil-forming rocks are also called water-ice. Such a name they received for the reason that they were formed due to the melted waters of glaciers. These sediments most often encircle the bottom and terminal moraines, often overlapping them. This is due to the gradual displacement of the edge of the glaciers. Fluvioglacial formations consist of small-scale or sand-and-shingle deposits forming glacier deltas, ozovyh ridges and other reliefs, eventually forming sand and pebble fields.

These rocks are characterized by a high grade of material, a clear stratification of the oblique, which is natural for the deposits of running water.

Soil-forming rocks of this type coexist with loam, which has a practically smoothed stratification. Specialists believe that such loamy deposits are formed by small spills of periglacial waters. Their structure is dense, viscous, yellowish in color. For this type, the content of boulders is not characteristic.

The cover loam is predominantly distributed in the territories of the watershed, lying on the moraine, from which, almost always, has a clear distinction.

Under the same natural conditions, loesslike loams may also occur. The chemical composition of soil-forming rocks of this type of loam is similar to integumentary, but differ in their carbonate content.

Mostly these deposits give the soil a low fertility. Lack of humus, nutrients, low moisture capacity of the material lead to this result. The formation of material in the basins littered with clays, with the gradual bogging of the area, leads to the formation of maternal soil-forming rocks of podzolic soils in these areas . At high humidity of the site, they can be bog-podzolic.

Lacustrine-glacial deposits

In the lowland regions, soil-forming rocks are formed on the basis of sedimentary material of lakes that fill low relief areas near glaciers. In this case, a predominantly horizontal stratified ribbon clay is found, but sometimes it is possible to stumble upon sand and sandy loam with virtually uninfected horizontal stratification.

Alluvial deposits

This group includes sediments that are formed in the river valleys, as well as in the mouths of rivers floods. These deposits have clearly pronounced stratification. The types of soil-forming rocks in the alluvial type of deposits will depend on the natural conditions, their composition may be sandy, clayey, loamy, etc.

Lacustrine deposits

Characterized by the absence of ribbon lamination inherent in lake-glacial formations. In addition, they are located mainly in the lake basins of different terms of formation.

Ozerno-alluvial deposits

As can be understood from the name, this group includes deposits of the alluvial type and the lake type. These deposits are formed in the lowlands of rivers and woodlands. Especially often occur in places of frequent and high water in the spring. Abundant moistening of rocks during a prolonged stagnation of water leads to the appearance of clay deposits of lake type. The fertile properties of soil-forming rocks of this type are low. In our country large areas in the territory of Western Siberia, Polesie, etc. are formed precisely by this type of deposits.

Proluene deposits

This definition is suitable for sediments formed by temporary descendants from the mountains. The material of these deposits is unsorted, consisting of gravel, pebble and boulder elements. You can meet these breeds at the mountain sights: even a small gorge can boast a significant amount of removals. Fusing, these materials are foothill plain plains. Very often they have a significant amount - a striking example of this can serve as a strip along the Kopetdag.

A distinctive feature, as one can understand, of proluvial deposits is the shape of a fan or cone. The composition of the prowl is varied. Near the mountain ranges, it is, mainly, the cartilaginous-gravelly formations, rather coarse. The farther away from the mountains the deposit is removed, the smaller its structure. At the greatest distance from the foothills of the ridges, the proluvium consists of sands and loam.

Eluvial deposits

Soil-forming rocks of this type are formed by weathering mountain formations that remain in their place.

Based on the composition of the primary rock and the nature of weathering, it is possible to judge what composition and species will be deposited. With various chemical effects of natural properties, it can be giant stone blocks or smooth clay products. Mountain peaks are rich in stony placers, while lowlands with a moist climate are lined with clay sediments.

Eluvium is characterized by a gradual transition of the color of the rocks and a slight difference in the mineralogical composition of the parent deposits from the resulting formations.

Deluvial deposits

The main soil-forming rocks of mountain types refer to this type of deposits. They are very closely related to the eluvial, being, as a matter of fact, washed from the hills by rain or meltwater by eluvium.

Soil-forming rocks of this type possess a grade and considerable stratification. Most often, the layers are parallel to the slope of the mountain. For the most part they consist of clay particles. The possibility of detecting large rocky debris is very small.

Such deposits are located in places of relief, near mountain ranges or at the foot of hills.

Eluvio-deluvial deposits

The nature of eluvial and deluvial deposits is such that in large areas they are in close proximity. With such an arrangement, it is difficult to distinguish between where one type of sediment begins and ends with another, or even impossible at all. Specialists decided that the soil-forming rocks in this case will be called eluvio-deluvial. They are always located in mountainous areas and areas with hilly terrain.

Aeolian deposits

The formation of such deposits is always associated with the accumulative activity of the wind.

Undoubtedly, eolian sediments are sand deposits that make up the area of deserts and semi-deserts. These formations create recognizable reliefs - dunes. It is from them that the origin of the breed can be attributed to the eolian type unerringly.

In geographic areas not related to deserts, soil-forming rocks of this type can also be found. These include dunes of different origin: sea, river, continental. These forms are formed by sandy sediments that have been transformed in the past, when the climatic conditions were different, or are in the process of being transported today - this process often occurs under the influence of human activity. In addition to morphological properties, eolian deposits strongly differ from all other types by diagonal stratification and high sorting.

Loess

These Quaternary soil-forming rocks occupy a huge place in the territory of our country. The steppes of the south and southeast practically on all extent consist of loess and loesslike loam. These types of rocks have characteristic features: looseness, lack of stratification, porosity. The most important difference is in the high content of magnesium and calcium carbonates.

Marine sediments

Marine soil-forming rocks of Russia are represented mainly in the Caspian lowland. Their formation in this area occurred during the last transgression of the Caspian Sea. These deposits are here in the form of chocolate plate-like dense clay, occasionally sand. Often these rocks have a strong salinity. In addition, marine sediments are characteristic of the shores of the Arctic Ocean.