When determining the volume and intensity of training loads that provide the optimal effect of adaptation, there are two possible ways. The first -- intensive way, consisting in a further increase in the total volume of training loads. On this path, the possibilities for further sports growth for highly qualified athletes are now practically exhausted. More promising in terms of further progress in world sports is the second option -- way of intensification of training activity. On this way, while maintaining the already achieved (almost limiting) volumes of the training load, such a combination of high-intensity, developing loads with supporting loads, maintaining the achieved level of functioning of the necessary systems, is proposed, which creates the best conditions for achieving sports success.

The experience of training the strongest athletes shows the possibility of an annual increase in the total amount of training load by 20%. In young athletes, this increase is possible by 40 - 50 % adapt to it depending on the type of athletics and its individual characteristics. Naturally, the intensity of exercises increases, which is expressed in an increase in the volume of the load performed at the maximum and near-limit speed in running; in increasing the length and height of jumps, throwing range, weight of projectiles and barbells; in a more energetic, increased tempo and rhythm special exercises. One of the indicators of the intensity of sports loads is the increase in the number of competitions.

Modern ideas about the ratio of volume and intensity of training loads in a year-round cycle suggest that the training process be structured in such a way that, without opposing the volume of intensity, periodically simulate the load and tension characteristic of competitions. Year-round applications of special training and the main type (main distance, main projectile, own jump, etc.) are an integral link in the modern training system. This structure makes it possible to expand the competitive calendar, making it year-round. At the same time, it is necessary to provide for the mandatory variability of loads based on the laws of adaptation, then highly qualified athletes will be able to show high results every 1.5 - 2 months.

An organic part of any exercise that affects the load is a properly organized rest. The rational alternation of work and rest underlies all sports training and extends to the repeated impact of the load in one session of the training day, throughout the week, month, year and years.

The repeated use of training and competitive loads is organically linked with the time intervals between them and with the recovery processes. The number of repetitions, exercises, the nature and duration of rest intervals depend on the tasks, means and methods of training, as well as on the characteristics of the types of athletics, the level of preparedness of the athlete and external conditions.

Between individual exercises and classes, in all cases, it is important to establish such breaks for rest, which, taking into account the amount of load used and the nature of the movements performed, provide an appropriate training effect. Depending on the form of organization relaxation happens passive and active. In between exercises that require precise movements and great concentration, leisure gives good results in the restoration of working capacity. For example, during classes in complex-coordinating types of athletics (hurdling, high jumps and pole vaults, hammer and javelin throwing), slow running, walking or short sports and outdoor games are used for recreation. And vice versa, during the lessons of cyclic types, it is possible to offer for rest a short-term performance of movements with complex coordination.

Each new repetition should not take place against the background of fatigue from previous actions. The duration of rest in these cases ranges from 1 minute (in throwing) to 3-4 minutes (in pole vaulting). As for the break between classes, at the first stage of training in sports equipment they should be carried out daily, and in the future - 3-4 times a week. If the break is 48 hours, then this leads to a decrease in the level of learned material of the lesson up to 25%, primarily due to the dulling of kinesthetic sensitivity.

In terms of duration, rest between loads can be divided into four types: 1) complete (ordinary); 2) incomplete (supercompensatory); 3) reduced (hard); 4) long (soft). By varying the rest intervals with the same volume (or intensity) of the load, it is possible to achieve different results in the development of motor qualities. For example, in cyclic athletics, incomplete rest provides the development of endurance to a greater extent, full rest - speed, reduced rest - speed endurance, and long rest provides recovery of working capacity after a strenuous part of the session or after overwork (overtraining).

The quantitative and qualitative components of the load are organically interconnected. But depending on the construction of the athlete's training process (tasks, means, methods, level of loads, etc.), the relationship between them is different, and accordingly, the adaptation processes are different. Qualitative changes(morphological, physiological, biochemical, psychological and biomechanical) cause changes in the quantitative side in the activity of the athlete's body. An important role in increasing the duration of the actions of exercises is the economization of the functions of the body of athletes, ensuring the performance of the same work at a lower cost of energy resources.

Performing any physical exercise takes time. And no matter how small it is, this is already a certain amount of work, which is the volume of the training or competitive load. And the amount of neuromuscular work that is performed per unit of time and is related to its volume determines the intensity of the load. Volume and intensity in sports are inseparable. They can exist separately only as concepts. In sports practice, these are two organically interrelated aspects of any physical exercise performed by an athlete. So, for example, the length of the distance and the duration of the run are the amount of training work (volume of load), and the speed of movement is its intensity; the number of throws performed by the thrower is the volume of the specific load, and the effectiveness of these throws is its intensity.

Quite accurately determines the level of the training load by the integral indicator of shifts in the body -- heart rate(heart rate). To do this, measure the pulse during exercise, after it and during the rest period. Comparing these indicators with the intensity of the load, with its direction and taking into account the recovery time after it, it is possible to more objectively manage the training process.

Table 2 gives an idea of ​​how the loads in sports can be classified according to the direction of their impact, which is based on taking into account the ways of energy supply to work. Under the same conditions, it is the direction of the load, which determines the degree of participation in the work performed by various organs and functions, indicates the degree of their oppression and the duration of recovery.

Table 2.

By magnitude, the load can be conditionally divided into maximum, large, medium and small. is within the capabilities of the athlete. Its criteria are the athlete's inability to continue the proposed task. The pulse at the same time reaches a value of 180 or more beats per minute (bpm). If by force of will the athlete tries to cross this limit, then the load becomes prohibitive and can lead to overtraining of the athlete.

in terms of the number of exercises and the intensity of movements, it is 70-80% of the maximum, that is, it makes it possible to continue the action against the background of fatigue. Pulse rates here can be in the range of 150--175 beats / min.

determined by the number of exercises and the intensity of movements within 40 - 60% of the maximum, i.e. the exercise continues until a feeling of fatigue appears. At the same time, heart rate indicators reach 120--145 beats / min.

is 20 - 30% of the maximum in terms of the number of exercises and intensity of movements. The motor task is performed easily, freely, without visible tension, and the pulse does not exceed 120 beats/min.

As the athlete's fitness increases, the load, which was initially considered as maximum, becomes large or medium at subsequent stages, etc. This is especially true for such a component of the load as intensity. The higher the intensity of the exercise, the longer it is, the greater the costs of the athlete's body, the greater the load on his psyche. It is necessary to take into account the requirements for such qualities as courage, determination, the will to win, etc. In principle, the higher the intensity of the training work, the smaller its volume, and vice versa. The level of intensity is determined primarily by the type of athletics. Where success is determined by maximum effort (jumping, throwing, sprinting), naturally, the level of intensity of special training work is also very high; in other sports (running for medium and long distances, race walking) the main thing is high average level movement speed.

With a view to more effective implementation an athlete of exercises, with a given training effort, should determine the intensity zones as the ratio of the given value of training or competitive stresses to the maximum possible data of the athlete. Table 3 shows the gradation of load by intensity zones in speed-strength types of athletics.

Table 3

The zone of 80-90% of the maximum in all types of athletics is considered a development zone. Applying a training load in zones of 90-100%, there is an impact on the development of speed, it should be included in almost every training session and built in such a way that during each session the load is applied in all zones of intensity, with its optimal ratio. The training load in the zones of 50-80% of the maximum solves mainly the problems of a special warm-up and recovery, which contributes to the favorable flow of the entire training process.

The result in athletics depends on high level endurance and dictates a certain selectivity of training effects, which are provided by aerobic (with oxygen access), anaerobic (without oxygen access) and aerobic-anaerobic (mixed) processes of the athlete's body. In Table 4, intensity zones are distributed according to heart rate indicators during a particular training work in the development of endurance.

Table 4

When using the aerobic mode of training effects, the pulse should be in the range of 120 - 160 beats / min. When performing a load in mixed mode, the pulse rate should reach 170-180 beats / min. Anaerobic training mode is possible with a pulse of 190 or more beats per minute.

Very important in determining the adequacy of the proposed loads is the control of the pulse during recovery. primary goal heart rate control is to determine the training voltage, to comply with the main requirement of training - to avoid excessive overstrain, preventing cases of overwork and overtraining. If the athlete's pulse after the load does not recover within a certain time to the desired level (for example, the pulse remains above 120 beats / min for more than 5-6 minutes after an average load), then this indicates that the load is probably very high and the training work (quantity, pace) should be reduced or stopped.

With high-speed training, the recovery time for heart rate to 120 beats / min should take 1 - 4 minutes between repetitions of exercises and 2 - 5 minutes between series to a pulse of 100 - 120 beats / min. When developing speed endurance, one should focus on restoring the pulse to 120-140 beats/min 1-3 minutes after the work is done, and between series the pulse should recover to 100-120 beats/min within 2-5 minutes. When recovering after a stressful workout (control run, assessment), the pulse should reach 100-120 beats / min for 4-10 minutes. Re-execution of such a load is possible after 10-20 minutes, if the pulse during the recovery period reaches less than 100 beats / min. Indicators for the termination of training work should be considered a pulse over 120 beats / min after 5 - 10 minutes of rest.

The levels of recovery of heart rate are somewhat individual and may be determined by age, the state of anaerobic functions, and genetic character. They can be between 108 --132 bpm. Recovery processes are also affected by the following points: the athlete is not in shape, training work is too hard, the previous training load was too high, illness, fatigue or overwork. For most athletes, the level of recovery of many body functions corresponds to a pulse of 120 beats / min. Athletes with greater genetic potential can recover faster even with high training load. With a large amount of work with reduced intensity, it is enough to reduce the heart rate to 120-140 beats / min during rest, in order to partially restore the energy potential, start working again. With a small amount of work with an above-average intensity, it is enough to achieve a heart rate of 120 beats / min during the rest period in order to be able to continue working as efficiently as at the beginning. When "acute", shock work with high intensity is performed, during the recovery (rest) period, the heart rate should reach 90--100 beats / min before repeating the proposed load.

Tectonic movements are one of the most important factors in the development of geological processes that change the face of the Earth. They lead to transformation earth's crust, change the landforms of the surface, the outlines of land and sea, thereby affecting the climate.

Tectonic movements affect volcanism, sedimentation processes and determine the distribution of minerals in the earth's crust.
Tectonic movements are expressed in the form of slow ups and downs, leading to transgressions and regressions of the sea in the form of a general collapse of the earth's crust with the formation of high

mountain ranges and deep depressions, the formation of folds, as well as in the form of destructive earthquakes, which are accompanied by the appearance of cracks with a significant displacement of crustal blocks vertically and horizontally.
Depending on the direction of stress, tectonic movements are divided into vertical (radial) and horizontal (tangential). In the analysis of vertical movements, ascending (positive) and descending (negative) movements are distinguished. These movements often correspond to slow, smooth ups and downs, covering the territories of continents and oceanic depressions or their parts. These are epeirogenic movements (Greek "epeiros" - mainland).
Tangential movements (tangential to the surface of the earth's crust) are associated with certain zones and lead to significant deformations of the earth's crust. These are orogenic movements (Greek "oros" - mountain).
Tectonic movements and the resulting structures of the earth's crust are studied by geotectonics and structural geology.
To restore the tectonic movements of past eras, special methods are used to recreate big picture tectonic movements for a certain epoch.
We judge the nature of modern tectonic movements by observing modern processes that are clearly manifested in areas of active earthquakes and volcanism: 1) modern vertical tectonic movements are fixed by repeated leveling; 2) the latest movements, i.e. that occurred in the Neogene-Quaternary time, are studied using geomorphological methods, analyzing the topography of the Earth's surface, the morphology of river valleys, the location of sea terraces, and the thickness of Quaternary deposits.
i, "It is much more difficult to study the tectonic movements of past geological epochs. The methods for studying these movements are: 1) analysis of the stratigraphic section; 2) analysis of lithological-paleogeographic maps; 3) analysis of thicknesses; 4) analysis of breaks and unconformities; 5) structural analysis, 6) paleomagnetic analysis, 7) formational analysis.

1. The analysis of the stratigraphic section makes it possible to trace the tectonic movements
   large area of ​​the earth's crust for a long time. Starting material for analysis
   is a stratigraphic section (column) that needs to be investigated from the standpoint of change
   of the conditions of accumulation of rocks in their stratigraphic sequence.

   By studying the material composition, structural and textural features of rocks, and the fossils contained in them, it is possible to identify the types of deposits that accumulate on various hypsometric
   levels relative to the water line of the sea basin and, accordingly, characterize the situation of sedimentation. Negative tectonic movements under conditions of stable removal of clastic material into the basin lead to a deepening of its bottom and a change up the section of shallow-water deposits by deeper ones. On the contrary, positive tectonic movements lead to the shallowing of the basin and the replacement of deep-water sediments along the section by shallow-water, terrestrial ones and further erosion of previously accumulated sediments. Negative tectonic movements contribute to the development of marine transgressions, while positive ones cause regression.
   2) Lithological-paleogeographical analysis. Analysis of lithological-paleogeographic maps makes it possible to judge the direction of movements and the distribution of troughs and uplifts in the area. Usually
   areas of accumulation of sediments correspond to a negative structure, areas of denudation - put
   body. Due to the differentiation of movements against the background of a large negative structure, areas of relative uplifts with marine shallow-water deposits can be distinguished among deeper ones. Such a site is an underwater uplift - shallow and may correspond to a growing anticline structure. Distribution area relatively deep-sea
   sediments among shallow waters should correspond to a depression at the bottom of the basin.

   Usually, the nature of tectonic movements is more clearly revealed in the analysis of lithological-paleogeographic maps compiled for several successive periods of time.
   3) Power analysis. In areas of accelerated subsidence, precipitation of greater
   power, in areas of slow deflection - less power, in areas of uplift -
   powers are zero.

   Data on the thicknesses of deposits of the same age are put on maps; points of equal power are connected by lines - isopachs (Fig. 23). Maps with isopachs can be used to judge the distribution of areas of relative troughs and uplifts. However, the power analysis must be combined with the analysis of facies
   Rice. 23. Map of equal thicknesses of a coeval sandy-argillaceous stratum (thickness contours indicate the position of a trough formed during sedimentation): / - measurement point and thickness (in m); 2 - power isolines (isopakhites). (Borrowed from G.I. Nemkov et al., 1986)
   noah environment of sediment accumulation, tk. it is applicable only for certain conditions of sedimentation, when the rate of subsidence of the bed is compensated by the rate of accumulation on it
   precipitation. In the case of a decompensated incision for huge periods of time,
   a thin layer of sediment accumulates.
   
   
   4) Analysis of breaks and disagreements. Positive tectonic movements in the stratigraphic section are expressed by the change of relatively deep-water deposits by shallow ones,
   shallow water - coastal and continental. In this case, if these movements led to
   rise of accumulated precipitation above sea level, their erosion begins. During subsequent subsidence, a new series of sediments falls on a eroded surface, which is called the break surface or the unconformity surface. These surfaces are fixed by falling out of the normal sequence of certain stratigraphic units that are present.
   where there were no positive developments. If deposits are above and below the surface,
   fixing a break in sedimentation, occur with the same angles of inclination (stratigraphic unconformity), we can talk about slow positive movements that engulfed
   large areas. If sharply different slope angles (angular unconformity) are observed, then the previously accumulated sediments experienced folding by the time of the new subsidence and sedimentation, and could be broken by ruptures (Fig. 24). The depth of erosion of the underlying stratum and
   the duration of the break in sedimentation indicates the amplitudes
   Rice. Fig. 24. Stratigraphic (a) and angular (b) unconformity Sequence of events: a - accumulation of sediments of the lower member, uplift, erosion of the top of the lower member, subsidence, accumulation of sediments of the upper member; b - accumulation of sediments of the lower members, uplift, folding and movement of blocks along the fault, erosion, accumulation of sediments of the upper member (borrowed from G.I. Nemkov et al., 1986)
   tectonic movements that led to disagreement between rock strata. The rock strata separated from the underlying and overlying deposits by the surfaces of angular unconformities are called structural floors. Each structural stage corresponds to a natural historical-tectonic stage in the development of the territory, which began with transgression and sedimentation during negative movements and ended with the rise of the territory and folding. Each structural floor is characterized by specific forms of layer occurrence.
   5) Structural analysis is essential in the study of horizontal movements,
   as it allows to qualitatively and quantitatively estimate the magnitude of horizontal movements during

   
   Rice. Fig. 25. Layer folded under lateral compression d is the length of the wing of the fold, w is the width of the fold, a is the angle of the fold (borrowed from G.I. Nemkov et al., 1986)
   layer deformation time. If you mentally straighten a layer that is folded into folds formed during lateral compression, the length of such a straightened layer will correspond to the initial width of the deflection before the layer was deformed. The difference between the sum of the lengths of the wings of the folds and the sum of the widths of the same folds will be the value of the horizontal compression of the layer (Fig. 25). Taking advantage graphically or geometric formulas, it is possible to estimate the amplitude of horizontal movements that led to the formation of folds. For example, according to fig. 25, it can be seen that if the average fold angles are 60°, the horizontal contraction of the surface was twofold.
   6) Paleomagnetic analysis. Ability rocks be magnetized during
   formations in accordance with the direction of the geomagnetic field and maintain this magnetization
   allows not only to create a paleomagnetic geochronological scale, but also to use paleomagnetic analysis data to identify horizontal tectonic movements. Having determined the average direction of the magnetization of rocks of a certain age, taken from any
   point on the surface of the Earth, it is possible to calculate the position of the magnetic pole of that time in
   
   
   coordinates. By examining the rocks in their stratigraphic sequence, the trajectory of the relative movement of the pole is drawn from the coordinates for the time corresponding to the studied interval of the stratigraphic section. Having done the same study on samples taken from another point, the trajectory of the movement of the pole relative to the point for the same period of time is drawn.
   Rice. 26. Trajectory of movement North Pole regarding Europe and North America over the last 400 million years (borrowed from G.I. Nemkov et al., 1986)
   If both trajectories coincide in shape, then both points have retained a constant position relative to the poles. If the trajectories do not coincide, then both points have changed their position relative to the pole in different ways. For example, the trajectories of the movement of the North Pole, calculated for the territory of North America and for Europe over the past 400 million years, are significantly different (Fig. 26). This allows us to draw a conclusion about the horizontal displacements of the continents at the specified time.
   7) Formational analysis is a method of studying the structure and history of development
   the earth's crust based on the study of the spatial relationships of rock associations -
   geological formations.
   A geological formation is a material category that occupies a certain position in the hierarchy of the matter of the earth's crust: chemical element- mineral - rock -geological formation - formational complex - shell of the earth's crust, -k Under formations is understood a set of facies that formed on a more or less significant area of ​​the earth's surface under certain tectonic and climatic conditions and differ from others in features of composition and structure. Separate facies can be formed in different parts of the earth's surface. However, their stable and long-term combinations, which allow them to be grouped into formations, occur only under strictly defined tectonic and climatic conditions. According to another definition, a geological formation can be called natural associations of rocks associated with the unity of the material composition and structure, due to the commonality of their origin (or location).
   The term "formation" was introduced by the famous German geologist A.G. Werner back in the 18th century. long time before the beginning of the 20th century. it was used as a stratigraphic category, as suggested by the author. Until now, in the United States, the term "formation" is used to designate stratigraphic units. In our country, formational analysis has found wide application in connection with tectonic zoning and the prediction of minerals. The credit for its development belongs to many Russian scientists, in particular N.S. Shatsky, N.P. Kheraskov, V.E. Khain, V.I. Popov, N.B. Vassoevich, L.B. Rukhin and other researchers.
   There are three types of formations: sedimentary, igneous and metamorphic. When studying formations, the main (obligatory) and secondary (optional) members of the association are distinguished. The main members of the association characterize a certain formation, i.e. stable association, repeating in space and time. The name of the formation is given by the name of the main members of the association. The set of minor members is subject to significant changes. Depending on the material composition, the types of formations are divided into groups. For example, among sedimentary formations, groups of clay-shale, limestone, sulfate-halogen, siliceous, fine-clastic-quartz, fine-clastic polymictic, etc. can be distinguished; among volcanogenic - groups of basalt-diabase (trap), liparite-dacitic, andesitic formations, etc.
   The main factors determining the formation of stable associations of sedimentary rocks are the tectonic regime and climate, and igneous and metamorphic rocks - the tectonic regime and thermodynamic environment.
   The main features of sedimentary formations are: 1) a set of their constituent associations of the main rocks, which together correspond to facies or genetic types; 2) the nature of the interbedding of these rocks in a vertical section; rhythmic structure; 3) the shape of the body of the formation and its thickness; 4) the presence in it of some characteristic authigenic minerals, peculiar rocks or ores; 5) the predominant color, to some extent carrying genetic information; 6) the degree of diagenetic or metamorphic changes.
   The names of sedimentary and sedimentary-volcanogenic formations are usually given according to the prevailing lithological components (sandy-argillaceous, limestone, dolomitic, evaporite) with the simultaneous indication of the physical and geographical setting of the formation (marine, continental, limnic), often many formations are named according to the presence of accessory minerals (glauconite) or minerals (coal-bearing, bauxite-bearing).
   The main factors that determine the appearance of sedimentary formations are the following: 1) the nature of the tectonic regime in the areas of erosion and accumulation; 2) climatic conditions; 3) intensity of volcanism. From the multiple combination of these conditions and rapid variability in space and time, an alternation of genetic types of rocks that make up the formations is created. The general distribution of formations on the earth's surface also depends on these factors.
   Depending on the tectonic regime, three classes of formations are distinguished: platform, geosynclinal, orogenic. Most sedimentary formations can serve reliably
   mi indicators of the tectonic regime. For example, formations of marl-chalk, kaolin
   clays, quartz sandstones, clay-flask testify to the platform mode of sedimentation
   co-accumulations, and sedimentary flysch, siliceous-carbonate, siliceous-shale, jasper
   formations are indicators of the geosynclinal regime. The wide development of sedimentary groups
   clastic formations indicates an orogenic regime.
   An even more definite conclusion about tectonic regimes can be made on the basis of an analysis of igneous formations, if we keep in mind that a number of rocks: basic - medium - acid ~

   alkaline ones correspond to the sequence of development of magmatic eruptions when the geosynclinal regime changes to orogenic and then to platform.
   The areas of distribution of certain formations are controlled by tectonic structures, the development of which determines the spatial limitation of formations. Therefore, by studying the patterns of distribution of formations in space, we thereby establish the placement of tectonic structures during the formation of formations. The evolution of the tectonic regime leads to a successive change in the context of geological formations. Having data on the conditions for the formation of rock complexes that change vertically, we can conclude that the tectonic regime has changed.
   So, for example, if a thick layer of flysch formations with characteristic thin, regularly rhythmically interbedded layers of sandstones, siltstones and mudstones, is overlain by a layer of coarse clastic marine and continental deposits - molasses, it is concluded that geosynclinal conditions have been replaced by orogenic ones. This conclusion is based on existing ideas about the tectonic conditions for the accumulation of flysch and molasse formations.
   Formation analysis makes it possible to classify tectonic structures, highlighting their special types, for example, types of troughs. The recurrence of typical formations in spatially separated structures makes it possible to outline the general stages in the history of the tectonic development of structures, to compare sets of formations of similar types of structures of different ages, etc.
   A special direction in the study and classification of sedimentary formations was the direction based on taking into account the content of industrial concentrations of certain types of minerals in them. On this basis, coal-bearing, salt-bearing, phosphorite-bearing, bauxite-bearing, iron ore, laterite, oil-bearing and a number of other formations are distinguished.
   The sequence in studying and identifying formations is as follows. First, in the section, rock strata are identified that differ in lithological composition, separated by clearly defined bedding surfaces, breaks or erosion boundaries (stratigraphic break and unconformities). Then, a group of rocks (associations) that are part of the selected natural complex is studied, i.e. paragenetic analysis. At the same time, the cyclicity of the formation structure or other structural and textural features are determined and studied. Next, the facies nature of each rock type included in the formation and their combination in the section are clarified, i.e. facies analysis is carried out. On this basis, the genetic type of deposits is determined, and the physical-geographical (landscape) environment of formation formation is established. In the final phase of formational analysis, the climatic and tectonic regimes of time and places of formation formation are determined. Thus, paleoclimatic and formation-tectonic analyzes are carried out.
   The theoretical significance of the study of sedimentary and sedimentary-volcanogenic formations lies in the possibility of reconstructing ancient tectonic, climatic, and landscape zonality based on them. The practical significance of formational analysis is determined by the confinement to certain formations of the corresponding types of minerals.

5. Ignatenko I.V., Khavkina N.V. Podburs of the Far North-East of the USSR // Geography and Genesis of Soils

Magadan region. - Vladivostok: Publishing House of the Far Eastern Scientific Center of the USSR Academy of Sciences. - S. 93-117.

6. Classification and diagnostics of Russian soils / L.L. Shishov [i dr.]. - Smolensk: Oikumena, 2004. - 342 p.

7. Soil-geographical zoning of the USSR. - M.: Publishing House of the Academy of Sciences of the USSR, 1962. - 422 p.

8. Soil science / ed. V.A. Kovdy, B.G. Rozanov. - Part 2. - M .: Higher. school, 1988. - 367 p.

UDC 631.48 (571.61) E.P. Sinelnikov, T.A. Chekannikova

COMPARATIVE EVALUATION OF THE INTENSITY AND DIRECTION OF THE PROCESSES OF TRANSFORMATION OF THE MATERIAL COMPOSITION OF THE PROFILE OF BLEACHED SOILS OF THE PLAIN TERRITORIES OF THE PRIMORSKY KRAI AND THE SODDY-PODZOLIC CARBONATE SOILS OF THE SOUTHERN TAIGA

WESTERN SIBERIA

The article provides a detailed analysis of the processes of transformation of the material composition of soils in South Siberia and Primorye. Significant differences in the intensity and direction of the leading elementary soil processes were not revealed.

Keywords: Primorsky Krai, Western Siberia, soddy-podzolic soils, carbonate soils, comparative assessment.

E.P. Sinelnikov, T.A. Chekannikova

COMPARATIVE ASSESSMENT OF PROFILE MATERIAL STRUCTURE TRANSFORMATION PROCESSES INTENSITY AND ORIENTATION ON THE FLAT TERRITORIES BLEACHED SOILS OF PRIMORSKY KRAI AND CESPITOSE-PODZOLIC CARBONATE SOILS IN THE WESTERN SIBERIA

The detailed analysis of soils material structure transformation processes in the southern Siberia and Primorsky Krai is conducted. Essential distinctions in the intensity and orientation of leading elementary soil processes are not revealed.

Key words: Primorsky Krai, Western Siberia, cespitose-podzolic soils, carbonate soils, comparative assessment.

The assessment of the degree of differentiation of the material composition of the soil profile as a result of the action of various elementary soil processes has long been integral part studies of the genetic properties of the soil cover of any region. The basis of such analyzes was laid by the works of A.A. Rode,

The features of differentiation of the material composition of soils in the southern part of the Russian Far East, in comparison with soils of other regions close in genetic parameters, were studied.

C.V. Zonn, L.P. Rubtsova and E.N. Rudneva, G.I. Ivanov and others. The result of these studies, based mainly on the analysis of genetic indicators, was the statement about the predominance of the processes of glazing, bleaching, pseudo-podzolization and the complete exclusion of podzolization processes here.

In this report, we have made an attempt to compare the direction and intensity of the processes of transformation of the material composition of the profile of bleached soils of the plain part of Primorye with soddy-podzolic residual-calcareous soils. Western Siberia based on quantitative indicators of the balance of the main elements of the material composition.

The choice of Siberian soils as a comparative variant is not accidental and is determined by the following conditions. First, the residual calcareous soddy podzolic soils of Siberia were formed on mantle loams with a high content of clay particles and exchangeable bases, which excludes fundamental differences already at the first stage of the analysis. Secondly, this is the presence of detailed monographic data and balance calculations of the transformation of the material composition, published by I.M. Gadzhiev, which greatly simplifies the fulfillment of our task.

For comparative analysis, we used the data of I.M. Gadzhiev along sections 6-73 (soddy-strongly podzolic) and 9-73 (soddy-weakly podzolic soils). As bleached soil options

Primorye, we took brown-bleached and meadow gley-weakly bleached soils. The initial data of these soils, as well as an assessment of the transformation of their material composition depending on the geomorphological location and degree of bleaching, are presented by us in the previous message. The main indicators of soddy-podzolic soils are presented in Table 1.

An analysis of the data in Table 1 of this report and Table 1 of the previous one shows two significant points: firstly, this is a fairly similar composition of parent rocks, and secondly, a pronounced division of the profiles of all analyzed sections into accumulative-eluvial and illuvial parts. So, according to E.P. Sinelnikov, the content of clay particles in the soil-forming rock of the plains of Primorye is 73-75%, for the southern taiga of Western Siberia 57-62%. The amount of clay fraction was 40-45 and 35-36 percent, respectively. The total value of exchangeable Ca and Mg cations in the lacustrine-alluvial deposits of Primorye is 22-26 meq per 100 grams of soil, in the covering loams of Siberia 33-34, the value of the actual acidity is 5.9-6.3 and 7.1-7.5 units, respectively. . pH. The residual carbonate content of rocks is manifested in the properties of the parent rocks of the analyzed sections of Siberia, but its effect on the physicochemical state of the upper horizons is minimal, especially in medium and strongly podzolic soils.

Investigating the problem of differentiation of the profile of soddy-podzolic soils, I.M. Gadzhiev notes a clear separation of the eluvial part, depleted in sesquioxides and enriched in silica, and the illuvial part, to some extent enriched in the main components of the material composition, in comparison with the overlying horizons. At the same time, no noticeable accumulation of oxides was found here in relation to the original rock and even reduced. A similar regularity is also manifested in the bleached soils of Primorye.

Referring to the works of A.A. Rode, I.M. Hajiyev believes that given fact confirms the regularity of the behavior of the substance during the podzol formation process, the essence of which "... consists in the total destruction of the mineral base of the soil and the transit discharge of the resulting products far beyond the soil profile" . In particular, according to I.M. Gadzhiev, the total amount of desiltation of the total thickness of soil horizons relative to the parent rock ranges from 42-44% in strongly podzolic soil to 1.5-2 in weakly podzolic.

Table 1

The main indicators of the material composition of residual-calcareous soddy-podzolic soils of Western Siberia (calculated according to I.M. Gadzhiev)

Horizon Estimated thickness, cm Particle content<0,001 мм Плотность, г/см3 Валовый состав почвы в целом, % Состав крупнозема, % Состав ила, %

2 o so o o o o o) 1_1_ o o 2 2 o o o o o 2 a) o_ o o o o< 2 о со о од < со о од О) 1_1_ со о /2 о со со о 2 а) о_ со о од < 2 о СО со о од < со о од О) 1_1_ со о £ /2 о со со о 2 а) о_ со о од <

Section 6-73 Soddy-strongly podzolic

А1 4 23 1.10 74.7 14.2 4.3 7.5 5.1 79.3 11.1 3.1 10.3 5.7 58.2 25.1 8.5 3.2 4, 6

А2 20 23 1.32 73.8 14.3 4.2 7.4 5.4 78.6 11.1 2.7 10.4 6.4 56.8 25.3 9.4 3.1 4, 2

Bh 18 40 1.43 70.0 16.7 5.5 5.9 4.8 74.4 14.3 4.0 7.5 5.6 55.8 27.9 12.7 2.6 3, four

B1 31 45 1.55 67.4 17.3 5.6 5.6 4.8 76.6 10.9 1.3 11.3 11.5 55.2 26.5 10.8 2.8 3, eight

B2 27 40 1.53 68.4 18.3 6.2 5.2 4.6 77.0 11.8 2.7 9.7 6.7 55.5 26.7 10.8 2.9 3, eight

BC 24 38 1.52 68.4 16.7 5.6 5.7 4.6 76.3 11.1 2.6 10.2 6.8 55.7 25.9 10.9 2.9 3, eight

C 10 36 1.52 68.4 16.2 6.3 5.7 4.5 75.7 10.8 1.7 10.0 10.4 55.9 25.7 11.3 2.9 3, 5

А1 6 23 0.89 72.0 14.6 4.3 7.0 5.0 76.1 12.0 2.6 9.7 7.3 56.6 24.2 10.8 3.1 3, 5

А2 8 29 1.20 72.1 14.4 4.6 7.0 4.9 78.2 10.4 2.2 11.2 7.3 56.4 24.5 10.6 3.1 3, 6

Bh 30 40 1.35 69.0 15.3 5.7 6.2 4.3 77.4 8.7 2.1 8.1 11.3 55.3 26.1 11.6 2.8 3, 5

B1 22 42 1.46 67.5 17.6 6.2 5.3 4.4 75.4 11.1 2.6 10.0 6.8 55.2 27.6 11.9 2.7 3, 6

B2 18 42 1.45 67.7 16.8 5.6 5.7 4.7 76.3 9.8 1.5 12.3 10.6 54.8 27.3 11.8 2.7 3, 7

BC 38 41 1.46 67.4 16.9 5.6 5.6 4.7 75.2 11.0 2.1 10.5 8.3 54.7 26.5 11.4 2.7 3, 6

C 10 35 1.48 67.4 16.0 5.5 5.9 4.1 74.2 11.5 2.7 8.9 8.6 55.2 25.4 10.7 2.9 3, 7

Similar calculations performed by the author for chernozem soils and gray forest soils showed complete identity of the direction and rate of rearrangement of the material composition in comparison with automorphic soils of the southern taiga subzone of Siberia. Wherein ". the chernozem leached from the soil horizons in terms of the composition of silt, iron and aluminum, in comparison with the original rock, practically repeats the soddy-weakly podzolic soil, the dark gray forest podzolic soil is close to the soddy-medium podzolic soil, and the light gray forest podzolized soil approaches the soddy-strongly podzolic soil according to these indicators. This state of affairs allowed the author to conclude, “...that the formation of modern soddy-podzolic soils occurs on an already previously well-differentiated mineral base, in general terms, deeply eluvial-transformed compared to the original rock, therefore, it is hardly appropriate to attribute the eluvial-illuvial differentiation of the profile only due to the podzol formation process in its modern sense”.

The closest in composition to the original rock is horizon C of weakly podzolic soil, and in terms of the analyzed thickness of the modern soil profile, it contained 4537 tons of silt, 2176 tons of aluminum and 790 tons of iron per hectare. In a profile of strongly podzolic soil close in thickness, similar indicators were: 5240, 2585 and 1162 tons per hectare. That is, only due to the increased migration of substances in the profile of strongly podzolic soil, equal in thickness to the original parent rock, 884 tons per hectare of silt, 409 tons of aluminum and 372 tons of iron should have been carried out. If we translate these indicators into a cubic meter, we get, respectively: 88.4; 40.9 and 37.2 kg. In reality, the profile of strongly podzolic soil, according to I.M. Gadzhiev, relative to the parent rock lost 15.7 kg of silica, 19.8 kg of aluminum and 11 kg of iron per m3.

If we consider the loss of analyzed substances in the profile of soddy-strongly podzolic soil relative to the initial content of substances in the rock of weakly podzolic soil, then we get that the loss of silt will be 135 kg/m3, and the accumulation of aluminum, on the contrary, will be 7.5 kg and iron 3.4 kg.

In order to understand the essence of the ongoing processes of transformation of the material composition of the soddy-podzolic soils of Western Siberia and compare the results with the bleached soils of the plains of Primorye, we decomposed, using the method of V.A. Targulian, the gross content of basic oxides per share coming to the coarse earth (> 0.001 mm) and the silty fraction. The results obtained for the soddy-podzolic soils of Siberia are presented in Table 2 (the corresponding indicators for the bleached soils of Primorye are given in.

The entire profile of the studied soils is fairly clearly divided into four zones: accumulative (horizon A1), eluvial (horizons A2 and Bh), illuvial (horizons B1, B2 and BC), and parent rock (horizon C), relative to which all calculations in Table 2. Such a division allows a more contrasting assessment of the essence and direction of the processes of transformation of the material composition within a specific soil profile and a total assessment of the balance of the material composition.

table 2

The main indicators of the balance of the material composition of residual-carbonate soddy-podzolic

soils relative to parent rock, kg/m3

Gori- Mechanical elements Content in coarse earth Content in clay fraction

Coarse earth Il SiO2 AI2O3 Fe2O3 SiO2 AI2O3 Fe2O3

1 2 ± 1 2 ± 1 2 ± 1 2 ± 1 2 ± 1 2 ± 1 2 ± 1 2 ±

Section 6-73 Soddy-strong podzolic

А1 37 34 -3 23 10 -13 28 27 -1 4 4 0 0.6 1.0 +0.4 13 6 -7 6 2 -4 2.5 0.8 -1.7

А2 187 201 +14 117 63 -54 142 158 +16 20 22 +2 3.2 5.4 +2.2 65 36 -29 30 16 -14 12.6 5.9 -6.7

Bh 168 200 +32 105 58 -47 127 149 +22 18 28 +10 2.9 8.0 +5.1 58 32 -26 27 16 -11 11.3 6.6 -4.7

B1 290 287 -3 181 197 +12 219 220 +1 31 31 0 5.0 9.7 -1.3 101 107 +6 47 54 +7 19.5 24.5 +5.0

B2 253 225 -27 157 187 +30 191 173 -18 27 27 0 4.3 6.1 +1.8 88 104 +16 41 50 +9 17.0 20.0 +3.0

BC 225 217 -8 140 148 +8 170 165 -5 24 24 0 3.8 5.6 +1.8 78 82 +4 36 38 +2 15.1 15.9 +0.8

Section 9-73 Soddy-weakly podzolic

А1 57 41 -16 32 12 -20 42 31 -11 6 5 -1 1.6 1.1 -0.5 18 7 -11 8 3 -5 3.4 1.3 -2.1

А2 80 68 -12 42 28 -14 56 53 -3 9 7 -2 2.1 1.5 -0.6 24 16 -8 11 7 -4 4.6 2.9 -1.7

Bh 285 242 -43 159 163 +4 211 187 -24 33 21 -12 7.8 5.1 -2.7 88 90 +2 41 43 +2 17.1 18.9 +1.8

B1 209 185 -24 117 136 +19 155 139 -15 24 20 -4 5.7 4.8 -0.9 65 75 +10 30 38 +8 12.5 16.2 +3.7

B2 171 152 -19 96 109 +13 127 116 -11 20 15 -5 4.7 2.3 -2.4 53 59 +6 25 30 +5 ​​10.3 12.8 +2.5

BC 361 329 -32 202 225 +23 267 248 -19 41 36 -5 9.9 6.9 -3.0 112 123 +11 52 60 +8 21.7 25.4 +3.7

Note. 1 - initial values; 2 - content currently.

Table 2 shows that the direction and intensity of the processes of transformation of the material composition of “related” soil pairs are far from unambiguous. In the eluvial zone of the strongly podzolic soil profile, coarse earth fractions are accumulated relative to the parent rock (+46 kg/m3) and silt is removed (-101 kg). In the illuvial zone of these soils, on the contrary, coarse earth is removed (-38 kg) and silt accumulates (+50 kg). The total balance of coarse earth as a whole along the profile is clearly neutral (+5 kg), taking into account some conventionality of the components of the calculated indicators. The total balance of sludge is negative -64 kg.

In the soddy-weakly podzolic soil in all zones of the profile, a decrease in the proportion of coarse earth relative to the parent rock is observed, totaling -146 kg. The accumulation of clay fraction (55 kg) is typical only for the illuvial part, and according to this indicator, horizons B of both strongly podzolic and weakly podzolic soils are practically close, 50–55 kg/m3, but the total accumulation of silt in horizons B prevails over its removal from the eluvial accumulative zone (+25 kg).

Thus, in soils of different degrees of podzolicity, the nature of the redistribution of mechanical elements is different both in direction and in quantitative indicators. In a strongly podzolic soil, there is a more powerful removal of silt from the surface horizons beyond the soil profile, while in a weakly podzolic soil, on the contrary, a weak removal of silt is observed with intensive removal of coarse earth from almost the entire thickness of the soil profile.

In the brown-bleached soil of Primorye (BO), the direction of the processes of redistribution of mechanical elements is of the same type as in strongly podzolic soil, but the intensity (contrast) is much higher. So, the accumulation of coarse earth in the mountains. A2 was 100 kg, and the removal from the illuvial stratum was 183, which is -81 kg in total, at +5 in strongly podzolic soil. The removal of silt is actively going on throughout the eluvial-accumulative part of the profile (-167 kg), and its accumulation in horizons B is only 104 kg. The total silt balance in the BP soil is -63 kg, which is almost identical to the strongly podzolic soil. In the meadow gley weakly bleached soil (LHb) the direction of the processes of redistribution of mechanical elements is almost the same as in the BS soil, but the intensity is much lower, although the total balance of elements is quite close and even exceeds the index of the more bleached soil.

Consequently, the intensity of the bleaching process does not really correlate with the nature of the redistribution of mechanical elements, although the brown-bleached soils are much older and have passed the stage of meadow gley soils in the past.

Analyzing the total and individual participation of basic oxides (NiO2, AI2O3, Fe2O3) in the material composition of coarse earth and silt of individual zones of the soil profile of the sections relative to the parent rock, the following features and regularities can be identified.

In horizon A1 of strongly podzolic soil, with the removal of 3 kg of coarse earth, the amount of oxides is 1.6 kg; in the eluvial part of the profile, the sum of basic oxides is 11 kg greater than the mass of coarse earth, while in the illuvial part, on the contrary, the mass of coarse earth is 14 kg greater than the sum of oxides.

In the humus horizon of weakly podzolic soil, the proportion of coarse earth is 4 kg more than the total content of oxides, in the eluvial zone this excess was 10 kg, and in the illuvial part - 20 kg.

In horizons A1 and A2 of the chills of Primorye, the mass of coarse earth practically coincides with the mass of basic oxides, and in horizons B it exceeds by almost 50 kg. In the eluvial-accumulative part of the profile of the meadow gley weakly bleached soil, the regularity is preserved, that is, the mass of coarse earth coincides with the mass of oxides, and in the illuvial horizons B it is 20 kg more.

In assessing the analyzed values, the redistribution of mechanical elements and basic oxides of the material composition of the soil is of great importance for the thickness of the calculated layer, therefore, for a real comparison of the direction and intensity of the processes, the obtained balance values ​​should be reduced to an equal layer in thickness. Taking into account the low thickness of the humus horizon of virgin podzolic soils, the calculated layer cannot be more than 5 cm. The results of such recalculations are given in Table 3.

The results of recalculation for equal thickness of the analyzed soil layer clearly show the fundamental difference in the redistribution of the material composition of the soddy-podzolic soils of Siberia and the bleached soils of Primorye, depending on the degree of expression of the main processes of soil formation.

Table 3

Balance of mechanical elements and basic oxides (kg) in the calculated layer 5x100x100 cm

relative to parent rock

Layer, horizons Mechanical elements Coarse earth (> 0.001) Silty fraction (<0,001)

>0,001 <0,001 SiO2 AІ2Oз Fe2Oз Ба- ланс SiO2 AІ2Oз Fe2Oз Баланс

Sod-strongly podzolic soil

A1 -3.7 -16.2 -1.2 0 +0.5 -0.7 -8.7 -5.0 -2.1 -5.8

А2 +В +6.0 -13.3 +5.0 +1.6 +0.9 +7.5 -7.1 -3.2 -1.5 -11.9

B -2.3, +3.0 -1.3 0 +0.1 -1.2 +1.6 +1.1 +0.5 +3.2

Sod-slightly podzolic soil

A1 -13.3 -16.6 -9.1 -0.8 -0.4 -10.3 -9.1 -4.1 -1.7 -14.9

А2 +В -7.1 -1.3 -3.5 -1.8 -0.4 -5.7 +0.8 -0.3 0 +0.5

B -3.0 +2.2 -1.8 -0.6 -0.3 -2.7 +1.1 +0.8 +0.4 +2.3

Brown-bleached soil

A1 +0.6 -22.2 0 +0.9 0 +0.9 -11.4 -8.1 -2.2 -21.7

A2 -9.9 -17.7 +5.4 +2.7 +0.9 +1.9 -8.9 -7.2 -1.8 -17.9

B -9.1 +5.2 -6.4 +0.1 -0.1 -6.4 -2.5 -0.5 +0.5 +2.7

Meadow gley slightly bleached soil

A1 -1.1 -19.0 -0.8 0 +0.3 -0.5 -0.1 -5.9 -2.2 -18.1

А2 +0.5 -13.0 +0.9 +1.0 +0.2 +2.1 -7.0 -3.7 -1.8 -12.4

B -6.6 +2.5 -5.6 +0.4 +0.2 -5.0 +1.9 +0.3 +0.5 +2.3

In particular, only in slightly podzolic soils is there a maximum removal of coarse earth over the entire profile relative to the original rock. The maximum falls on the humus horizon. The accumulation of coarse earth in the eluvial part of the bleached soil profile is 2–3 times higher than in the strongly podzolic soil.

In all analyzed sections, there is an intensive removal of silt from the humus horizon: from 16 kg in podzolic soils to 19-22 in bleached ones. In the eluvial part of the profile, the removal of silt is somewhat less and is almost the same for all sections (13–17 kg). The only exception is the section of weakly podzolic soil, where the removal of silt is minimal - 1.3 kg. In the illuvial part of the profile of all sections, silt accumulates from 2 to 5 kg per 5 cm soil layer, which is absolutely unequal to its removal from the overlying strata.

Most researchers of podzolic and related soils are inclined to believe that the main criterion for the decomposition of silt (podzolization) or its uniformity in profile (lessification) is the indicator of the molecular ratio SiO2 / R2O3, although there are contradictions. In particular, S.V. Zonn et al. emphasize that under conditions of frequent changes in reducing and oxidizing conditions, which is typical for Primorye, there is a significant change not in light, but in large fractions of the granulometric composition of soils, and especially in the content of iron, which, when released, passes into a segregated state. And this, according to the authors, is the fundamental difference between the chemistry of brown-bleached soils and soddy-podzolic soils.

Based on these provisions, we compared the molecular ratios SiO2 / R2O3 and AI2O3 / Fe2O3 in the “coarse-earth” and silt of the sections, taking their value in the parent rock as 100%. Naturally, a value of less than 100% indicates a relative accumulation of sesquioxides in a certain part of the soil profile, and, conversely, a value of more than 100% indicates their decrease. The data obtained are presented in table 4.

An analysis of the data in Table 4 makes it possible to notice that, judging by the SiO2 / R2O3 ratio of the clay fraction, there are no significant differences between the horizons of podzolic soils (± 7%). In the sections of bleached soils, this trend persists, but the level of expansion of molecular ratios in horizons A1 and A2 reaches 15–25%, depending on the degree of bleaching.

The value of the AI2O3/Fe2O3 ratio in the clay fraction of the section of weakly podzolic and strongly bleached soils is really stable over all horizons and, on the contrary, differs significantly from that of strongly podzolic and

weakly bleached soils. That is, an unambiguous conclusion about the degree of silt differentiation depending on the severity of the main process of podzol formation or bleaching in the sections under consideration cannot be made.

Table 4

Analysis of the magnitude of molecular ratios relative to the parent rock

Soddy-podzolic soils Bleached soils

strong-weak-strong-weak-

podzolic podzolic bleached bleached

Horizon 3 O3 2 SI /2 o s/e 3 O3 2 1_1_ /3 O3 s 3 O3 2 si 2 o s/e 3 O3 2 1_1_ /3 O3 s 3 O3 2 SI 2 o s/e 3 O3 2 1_1_ / 3 O3 s 3 O3 2 si 2 o s / e 3 O3 2 1_1_ /3 O3<

Fractions of "coarse earth" (> 0.001 mm)

A1 103 55 109 110 108 97 100 100

A2 104 64 126 110 115 87 112 105

B 97 64 138 160 101 87 80 103

C 100 100 100 120 100 100 100 100

Fractions "silt" (< 0,00" мм)

A1 110 131 107 94 126 104 124 120

A2 107 120 107 97 115 98 103 122

B 100 108 93 100 100 102 100 107

C 100 100 100 100 100 100 100 100

The A12O3 / Pb20s ratio in coarse soil is somewhat more pronounced in the profile of strongly podzolic soil (-40; -45%) and bleaching -13%. In the soil profiles of the weakly pronounced ESP type, this ratio has an opposite positive trend (+5; +10%), and the maximum deviation from the parent rock (+60%) is in the B horizon of the weakly podzolic soil.

Thus, neither the initial data on the material composition, nor attempts to analyze them using various calculated indicators revealed clearly pronounced differences both between podzolic and bleached soil types, and depending on the degree of severity of the leading type of elementary soil formation process, in this case, podzol formation and lessivage. .

Obviously, the fundamental differences in their manifestation are due to more dynamic processes and phenomena associated with humus formation, physical and chemical state, and redox processes.

Literature

1. Gadzhiev I.M. Soil evolution of the southern taiga of Western Siberia. - Novosibirsk: Nauka, 1982. - 278 p.

2. Zonn S.V. On brown forest and brown pseudopodzolic soils of the Soviet Union // Genesis and geogra-

fia soils. - M.: Nauka, 1966. - S.17-43.

3. Zonn S.V., Nechaeva E.G., Sapozhnikov A.P. Processes of pseudo-podzolization and lessivation in forest soils of southern Primorye// Soil Science. - 1969. - No. 7. - P.3-16.

4. Ivanov G.I. Soil formation in the south of the Far East. - M.: Nauka, 1976. - 200 p.

5. Organization, composition and genesis of soddy-pale-podzolic soil on cover loams / V.A. Tar-gulyan [and others]. - M., 1974. - 55 p.

6. Podzolic soils of the central and eastern parts of the European territory of the USSR (on loamy soil-forming rocks). - L.: Nauka, 1980. - 301 p.

7. Rode A.A. Soil-forming processes and their study by the stationary method // Principles of Organization and Methods of Stationary Study of Soils. - M.: Nauka, 1976. - S. 5-34.

8. Rubtsova P.P., Rudneva E.N. On some properties of brown forest soils in the foothills of the Carpathians and plains of the Amur region // Eurasian Soil Sci. - 1967. - No. 9. - S. 71-79.

9. Sinelnikov E.P. Optimization of the properties and regimes of periodically waterlogged soils / FEB DOP RAS, Primorskaya GSHA. - Ussuriysk, 2000. - 296 p.

10. Sinelnikov E.P., Chekannikova T.A. Comparative analysis of the balance of the material composition of soils with different degrees of bleaching in the plain part of Primorsky Krai. Vestn. KrasGAU. - 2011. - No. 12 (63). - P.87-92.

UDC 631.4:551.4 E.O. Makushkin

DIAGNOSIS OF SOILS IN THE UPPER DELTA SELENGI*

The article presents the diagnostics of soils in the upper reaches of the delta of the river. Selenga on the basis of morphogenetic and physicochemical properties of soils.

Key words: delta, soil, diagnostics, morphology, reaction, humus content, type, subtype.

E.O.Makushkin SOILS DIAGNOSTICS IN THE SELENGA RIVER DELTA UPPER REACHES

The soils diagnostics in the Selenga river delta upper reaches on the basis of soils morphogenetic, physical and chemical properties is presented in the article.

Key words: delta, soil, diagnostics, morphology, reaction, humus content, type, subtype.

Introduction. The uniqueness of the river delta Selenga is that it is the only freshwater deltaic ecosystem in the world with an area of ​​more than 1 thousand km2, included in the list of specially protected natural sites of the Ramsar Convention. Therefore, it is of interest to study its ecosystems, including soil ones.

Previously, in the light of the new classification of soils in Russia, we diagnosed the soils of elevated areas of the terraced floodplain and the large island (island) of Sennaya in the middle part of the delta, small and large islands of the peripheral part of the delta.

Target. Carry out classification diagnostics of soils in the upper reaches of the delta, taking into account the presence of a certain contrast in the landscape and the specifics of the influence of natural and climatic factors on soil formation.

Objects and methods. The objects of research were alluvial soils of the upper reaches of the delta of the river. Selenga. Key sites were represented in the near-channel and central floodplain of the main riverbed near the village (village) of Murzino, Kabansky district of the Republic of Buryatia, as well as on islands with local names: Dwelling (opposite the village of Murzino), Svinyachiy (800 m from the village of Murzino upstream).

Comparative geographic, physicochemical and morphogenetic methods were used in the work. The classification position of soils is given according to. In the methodological aspect, taking into account the requirements, the work focuses primarily on the morphogenetic and physico-chemical properties of the upper humus horizons. The numbering of the buried horizons was carried out, starting from the bottom of the soil profile, with Roman capital numerals, as is customary in the study of soil formation in river floodplains.

Results and discussion. About with. Murzino, a number of soil cuts were laid. The first three soil sections were laid along the transect in areas from the lowland facies in front of the artificial dam, directly near the village in the direction of the main left channel of the Selenga River, formed in

Exam material

Ticket number 6.

1. Zoning is the main method of geographical research: what is a district, the main factors in the formation of districts, the importance of zoning, signs of zoning and types of districts.

2.Study of the types of zoning of the territories of Russia.

Ticket number 7.

1. The administrative-territorial structure of Russia: what is the administrative-territorial division and its main functions, federation, subjects of the federation and the principles of their allocation, federal districts.

2. Establish the composition of the federal districts of Russia.

Ticket number 8.

1. Natural conditions and resources of Russia: what are natural conditions and natural

resources, types of natural resources.

2.0 assessment of natural conditions and resources of the natural region of Russia.

Ticket number 9.

1. Relief of Russia: main features, mountains and plains.

2. To establish the dependence of the distribution of the largest landforms on the structural features of the earth's crust.

Ticket number 10.

1. Mineral resources of Russia and their use: distribution of minerals in Russia, types of mineral resources by aggregate state and industrial use, Russia's position in the world in terms of value and mineral reserves.

2. Explore the features of the distribution of mineral resources in Russia.

Ticket number 11.

1. The earth's crust and man: the influence of the earth's crust and the geological processes occurring in it on the life and economic activity of people; the impact of human economic activity on the surface of the earth's crust and the structure of its upper part.

2. To study the features of the manifestation of the internal forces of the Earth on the territory of Russia.

Ticket number 12.

1. Climate of Russia: factors influencing the formation of the Russian climate, the impact of geographical location and significant differences in the amount of total solar radiation on air temperature and the intensity of natural processes between the northern and southern regions of the country.

2. Analyze the distribution of total solar radiation and radiation balance on the territory of Russia

Ticket number 13.

1. The climate of Russia: the influence of relief features on the climate of Russia, the types of air masses in Russia and their impact on the climate of different parts of the country, the Asian maximum and its influence on the territory of Russia.

2. Determine the types of climate according to the description and establish the city (geographical object) located in this type of climate according to the climatograms

Ticket number 14.

1. Climate of Russia: distribution of air temperatures, atmospheric precipitation and humidity over the territory of Russia.

2. Establish similarities and differences in the distribution of summer and winter air temperatures and identify moisture features in different parts of Russia.

Ticket number 15.

1. Climatic zones and regions: indicators of differences and main features of the climate of climatic zones and regions of Russia.

2. Analysis of the main indicators of climate types in Russia.

Ticket number 16.

1. Atmospheric fronts, cyclones and anticyclones: how they arise and affect the weather.

2. Determine the type of weather according to characteristic features.

Ticket number 17.

4. Specify the subjects of the Russian Federation with the highest natural population growth. What is it connected with?

Ticket number 24.

2. Explore the features of the age and sex pyramid of Russia (see atlas, p. 22).

"Assistant"

1. How do the modern gender and age pyramid reflect the traces of major social upheavals experienced by Russia in the 20th century?

2. Determine in which age groups of the population the greatest excess of women over men is observed?

3. What proportion of the country's population are men and women? What are the causes of gender imbalance?

Ticket number 25.

2. Explore the features of the ethnic, linguistic and religious composition of the population of the European part of Russia (see atlas, pp. 24-25).

"Assistant"

1. Determine what peoples inhabit the European part of Russia? What language families and groups do they belong to?

2. What peoples living here are among the largest (more than 1 million people)? Determine the most multinational regions of the European part of Russia.

4. In what subjects of this part of the Russian Federation do indigenous peoples prevail?

5. Which language families and groups are the largest and which are the smallest?

b. Determine what religions are professed by the population of the European part of Russia? Which of them is the most common among believers?

7. Establish the main areas of distribution of Islam and Buddhism - Lamaism and the peoples professing these religions.

8. How to explain the diversity of peoples, languages ​​and religions of the European part of Russia?

Ticket number 26.

2. Explore changes in population density within the Main Settlement Zone of Russia (see atlas, pp. 22-23).

"Assistant"

1. Determine the areas of the country with the highest population density.

2. Set the value of the prevailing population density in the European part of the country. Where is it maximum and minimum?

H. How are the population densities changing in the area between Tyumen and Irkutsk?

4. What population density prevails in the area from Ulan-Ude to Vladivostok?

5. Compare the cards "Favorability of natural conditions for people's lives" and

“Population placement” and formulate a conclusion.

Ticket number 27.

2. Explore the features of the location of cities on the territory of Russia (see atlas p. 22-

"Assistant"

1. Determine which part of Russia (European or Asian) has more cities?

2. Count the number of millionaire cities, the largest and largest cities in the European and Asian parts of Russia and formulate a conclusion.

3. Establish how the number of cities with a population of more than 500 thousand people correlates with the main settlement zone and the favorable natural conditions for people's lives.

4. Determine how the modern urban population of Russia has changed? What is it connected with?

Ticket number 28.

2. Explore geographic differences in migration growth (loss) of the population on the territory of Russia (see atlas p. 25).

"Assistant"

1. Determine the subjects of the Russian Federation with the highest migration growth rate.

2. Set the subjects of the Russian Federation with migration loss.

H. Formulate a reasonable conclusion about the causes of modern migration flows on the territory of Russia.

Considered at the Methodological Association and recommended for the exam in geography "Russia: nature, population, economy", grade 8.

The relief-forming role of vertical tectonic movements of a higher order also lies in the fact that they control the distribution of areas occupied by land and sea (cause marine transgressions and regressions), determine the configuration of continents and oceans.

The distribution of areas occupied by land and sea, as well as the configuration of continents and oceans, is known to be the root cause of climate change on the Earth's surface. Consequently, vertical movements have not only a direct effect on the relief, but also indirectly, through the climate, the effect of which on the relief was discussed above (Chapter 4).

RELIEF-FORMING ROLE OF THE LATEST TECTONIC MOVEMENTS OF THE EARTH'S CRUST

In the previous chapters, we discussed the reflection of geological structures in the relief and the influence on the relief of various types of tectonic movements, regardless of the time of manifestation of these movements.

It has now been established that the main role in the formation of the main features of the modern relief of endogenous origin belongs to the so-called latest tectonic

Rice. 12. Scheme of the latest (Neogene-Quaternary) tectonic movements on the territory of the USSR (according to, greatly simplified): / - areas of very weakly expressed positive movements; 2-areas of weakly expressed linear positive movements; 3 - areas of intense dome uplift; 4 - areas of weakly pronounced linear ups and downs; 5 - areas of intense linear uplifts with large (o) and significant (b) gradients of vertical movements; 6 - areas of emerging (a) and prevailing (b) subsidence; 7-boundary of areas of strong earthquakes (7 points and more); c - boundary of manifestation of Neogene-Quaternary volcanism; 9 - border of distribution of operating

dvizheniyam, by which most researchers understand the movements that took place in the Neogene-Quaternary time. This is quite convincingly evidenced, for example, by a comparison of the hypsometric map of the USSR and the map of recent tectonic movements (Fig. 12). Thus, areas with weakly pronounced vertical positive tectonic movements in the relief correspond to plains, low plateaus and plateaus with a thin cover of Quaternary deposits: the East European Plain, a significant part of the West Siberian Lowland, the Ustyurt Plateau, the Central Siberian Plateau.

The areas of intense tectonic subsidence, as a rule, correspond to lowlands with a thick thickness of Neogene-Quaternary sediments: the Caspian lowland, a significant part of the Turan lowland, the North Siberian lowland, the Kolyma lowland, etc. The mountains correspond to areas of intense, predominantly positive tectonic movements: the Caucasus, Pamir , Tien Shan, mountains of the Baikal and Transbaikalia, etc.

Consequently, the relief-forming role of the latest tectonic movements manifested itself primarily in the deformation of the topographic surface, in the creation of positive and negative relief forms of various orders. Through the differentiation of the topographic surface, the latest tectonic movements control the location on the Earth's surface of areas of removal and accumulation and, as a consequence, areas with a predominance of denudation (worked out) and accumulative relief. The speed, amplitude and contrast of the latest movements significantly affect the intensity of manifestation of exogenous processes and are also reflected in the morphology and morphometry of the relief.

The expression in the modern relief of structures created by neotectonic movements depends on the type and nature of neotectonic movements, the lithology of deformable strata, and specific physical and geographical conditions. Some structures are directly reflected in the relief, in the place of others an inverted relief is formed, in the place of the third - various types of transitional forms from direct to inverted relief. The variety of relationships between relief and geological structures is especially characteristic of small structures. Large structures, as a rule, find direct expression in the relief.

Landforms that owe their origin to neotectonic structures are called morphostructures. At present, there is no single interpretation of the term "morphostructure" either in terms of the scale of forms, or in terms of the nature of the correspondence between the structure and its expression in relief. Some researchers understand by morphostructures both direct and inverted, and any other relief that has arisen at the site of a geological structure, while others understand only direct relief. The point of view of the latter is perhaps more correct. By morphostructures we will call landforms of different scales, the morphological appearance of which largely corresponds to the types of geological structures that created them.

The data currently available to geology and geomorphology indicate that the earth's crust experiences deformations almost everywhere and of a different nature: both oscillatory, and folding, and rupture-forming. So, for example, at present, the territory of Fennoscandia and a significant part of the territory of North America, adjacent to the Hudson Bay, are experiencing uplift. The uplift rates of these territories are very significant. In Fennoscandia, they are 10 mm per year (sea level marks made in the 18th century on the shores of the Gulf of Bothnia are raised above the present level by 1.5-2.0 m).

The shores of the North Sea within Holland and its neighboring areas are sinking, forcing the inhabitants to build dams to protect the territory from the onset of the sea.

Intense tectonic movements are experienced by areas of Alpine folding and modern geosynclinal belts. According to available data, the Alps rose by 3-4 km during the Neogene-Quaternary, the Caucasus and the Himalayas rose by 2-3 km only during the Quaternary, and the Pamirs by 5 km. Against the background of uplifts, some areas within the areas of Alpine folding experience intense subsidence. Thus, against the background of the uplift of the Greater and Lesser Caucasus, the Kuro-Araks lowland enclosed between them is experiencing intense subsidence. Evidence of the multidirectional movements existing here is the position of the coastlines of the ancient seas, the predecessors of the modern Caspian Sea. Coastal sediments of one of these seas - late Baku, the level of which was located at an absolute height of 10--12 m, are currently traced within the southeastern periclinal of the Greater Caucasus and on the slopes of the Talysh Mountains at absolute elevations of + 200-300 m, and within The Kura-Araks lowland was opened by wells at absolute elevations of minus 250-300 m. Intense tectonic movements are observed within the mid-ocean ridges.

The manifestation of neotectonic movements can be judged by numerous and very diverse geomorphological features. Here are some of them: a) the presence of sea and river terraces, the formation of which is not associated with the impact of climate change; b) deformations of sea and river terraces and ancient surfaces of denudation alignment; c) deeply submerged or highly elevated coral reefs; d) flooded marine coastal forms and some underwater karst sources, the position of which cannot be

explain by eustatic fluctuations1 in the level of the World Ocean or other reasons;

e) antecedent valleys formed as a result of sawing by the river of a tectonic rise that occurs in its path - an anticline fold or block (Fig. 13),

The manifestation of neotectonic movements can also be judged by a number of indirect signs. Fluvial landforms are sensitive to them. Thus, areas experiencing tectonic uplifts are usually characterized by an increase in density and depth.

erosional dismemberment in comparison with territories that are tectonically stable or experiencing immersion. The morphological appearance of erosional forms also changes in such areas: valleys usually become narrower, slopes become steeper, there is a change in the longitudinal profile of rivers and sharp changes in the direction of their flow in plan, which cannot be explained by other reasons, etc. Thus, there is a close relationship between the nature and the intensity of the latest tectonic movements and the morphology of the relief. This connection allows the wide use of geomorphological methods in the study of neotectonic movements and the geological structure of the earth's crust.

1 Eustatic fluctuations are slow changes in the level of the World Ocean, occurring simultaneously and with the same sign over the entire area of ​​the ocean due to an increase or decrease in the flow of water into the ocean.

In addition to the latest tectonic movements, there are so-called modern dvizheniya, under which, according to

Understand the movements in historical time and manifesting now. The existence of such movements is evidenced by many historical and archaeological data, as well as data from repeated leveling. The high speeds of these movements noted in a number of cases dictate the urgent need to take them into account in the construction of long-term structures - canals, oil and gas pipelines, railways, etc.

CHAPTER 6 MAGMATISM AND RELIEF FORMATION

Magmatism plays an important and very diverse role in relief formation. This applies to both intrusive and effusive magmatism. The relief forms associated with intrusive magmatism can be both the result of the direct influence of igneous bodies (batholiths, laccoliths, etc.), and the result of the preparation of intrusive igneous rocks, which, as already mentioned, are often more resistant to external forces than the host rocks. their sedimentary rocks.

Batholiths are most often confined to the axial parts of anticlinoria. They form large positive relief forms, the surface of which is complicated by smaller forms, which owe their appearance to the influence of various exogenous agents, depending on specific physical and geographical conditions.

Examples of rather large granitic batholiths on the territory of the USSR are a massif in the western part of the Zeravshan Range in Central Asia (Fig. 14), a large massif in the Konguro-Alagez Range in Transcaucasia.

Laccoliths occur singly or in groups and are often expressed in relief with positive forms in the form of domes "li" loaves. Well-known laccoliths of the North Caucasus

Rice. 15. Laccoliths of Mineralnye Vody, North Caucasus (fig.)

(Fig. 15) in the area of ​​the town of Mineralnye Vody: the mountains of Beshtau, Lysaya, Zheleznaya, Zmeinaya, and others. Typical laccoliths, well expressed in the relief, are also known in the Crimea (mountains Ayu-Dag, Kastel).

Laccoliths and other intrusive bodies often have vein-like branches called apophyses. They cut the host rocks in different directions. The prepared apophyses on the earth's surface form narrow, vertical or steeply dipping bodies, resembling collapsing walls (Fig. 16.5- B). Stratum intrusions are expressed in relief in the form of steps similar to structural steps formed as a result of selective denudation in sedimentary rocks (Fig. 16, L-L). Prepared sheet intrusions are widespread within the Central Siberian Plateau, where they are associated with the intrusion of rocks. trap formation 1.

Magmatic bodies complicate the folded structures and their reflection in the relief. Clearly reflected in the relief are formations associated with the activity of effusive magmatism, or volcanism, which creates a completely unique relief. Volcanism is an object of study of a special geological science - volcanology, but a number of aspects of the manifestation of volcanism are of direct importance for geomorphology.

Depending on the nature of the outlet openings, eruptions are distinguished areal, linear and central. Areal eruptions led to the formation of vast lava plateaus. The most famous of them are the lava plateaus of British Columbia and the Deccan (India).

Rice. 16. Prepared intrusive bodies: BUT-BUT- plastovan intrusion (sill); B-B secant vein (dike)

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In the modern geological era, the most common type of volcanic activity is the central type of eruptions, in which magma flows from the interior to the surface to certain "points", usually located at the intersection of two or more faults. The flow of magma occurs through a narrow feeding channel. The products of the eruption are deposited periclinally (that is, with a fall in all directions) relative to the outlet of the supply channel to the surface. Therefore, a more or less significant accumulative form, the volcano itself, usually rises above the center of the eruption (Fig. 17).

In a volcanic process, one can almost always distinguish between two stages - explosive, or explosive, and eruptive, or the stage of ejection and accumulation of volcanic products. The channel-like path to the surface breaks through in the first stage. The release of lava to the surface is accompanied by an explosion. As a result, the upper part of the channel expands like a funnel, forming a negative relief form - a crater. The subsequent outpouring of lava and the accumulation of pyroclastic material occur along the periphery of this negative form. Depending on the stage of volcano activity, as well as the nature of the accumulation of eruption products, several morphogenetic types of volcanoes are distinguished: maars, extrusive domes, shield volcanoes, stratovolcanoes.

Maar- negative landform, usually funnel-shaped or cylindrical, formed as a result of a volcanic explosion. There are almost no volcanic accumulations along the edges of such a depression. All currently known maars are non-active, relic formations. Big number Maar is described in the Eifel region in Germany, in the Massif Central in France. Most of the maars in a humid climate are filled with water and turn into lakes. Maar sizes - from 200 m to 3.5 km in diameter at a depth of 60 to 400 m

Rice. 17. Volcanic cones. Craters and barrancos on the slopes are clearly visible

Naples "href="/text/category/neapolmz/" rel="bookmark">Naples) arose within a few days literally out of the blue and is currently a hill up to 140 m high. The largest volcanic structures are stratovolcanoes. The structure of stratovolcanoes involves both layers of lavas and layers of pyroclastic material. Many stratovolcanoes have an almost regular conical shape: Fujiyama in Japan, Klyuchevskaya and Kronotskaya salts in Kamchatka, Popokatepetl in Mexico, etc. (see Fig. 17). Among these formations, mountains 3-4 km high are not uncommon. Some volcanoes reach 6 km. Many stratovolcanoes carry eternal snow and glaciers on their peaks.

Many extinct or temporarily inactive volcanoes have craters occupied by lakes.

Many volcanoes have so-called calderas. These are very large, currently inactive craters, and modern craters are often located inside the caldera. Calderas up to 30 km across are known. At the bottom of the calderas, the relief is relatively even; the sides of the calderas facing the center of the eruption are always very steep. The formation of calderas is associated with the destruction of the volcanic vent by strong explosions. In some cases, the caldera has a failed origin. In extinct volcanoes, the expansion of the caldera may also be associated with the activity of exogenous agents.

A peculiar relief is formed by liquid products of volcanic eruptions. Lava erupted from the central or side craters flows down the slopes in the form of streams. As already mentioned, the fluidity of lava is determined by its composition. Very thick and viscous lava has time to harden and lose mobility even in the upper part of the slope. At very high viscosity, it can solidify in the vent, forming a giant "lava column" or "lava finger", as was the case, for example, during the eruption of Pele volcano in Martinique in 1902. Usually, a lava flow looks like a flattened shaft stretching down the slope , with a very pronounced swelling at its end. Basaltic lavas can give rise to long flows that extend for many kilometers and even tens of kilometers and stop their movement on a plain or plateau adjacent to the volcano, or within the flat bottom of the caldera. Basalt flows 60-70 km long are not uncommon in the Hawaiian Islands and Iceland.

Lava flows of liparitic or andesitic composition are much less developed. Their length rarely exceeds several kilometers. In general, for volcanoes ejecting products of acidic or intermediate composition, a much larger part by volume is pyroclastic rather than lava material.

While solidifying, the lava flow is first covered with a crust of slag. In the event of a break in the crust in any place, the uncooled part of the lava flows out from under the crust. As a result, a cavity is formed - lavagrotto, or lava cave. When the cave roof collapses, it turns into a negative surface relief form - lavochute. Troughs are very characteristic of the volcanic landscapes of Kamchatka.

The surface of the frozen stream acquires a kind of microrelief. The most common are two types of lava flow surface microrelief: a) blocky microrelief and b) gut lava. Blocky lava flows are a chaotic heap of angular or melted blocks with numerous failures and grottoes. Such lumpy forms arise when high content gases in the composition of lavas and at a relatively low flow temperature. Intestinal lavas are distinguished by a bizarre combination of frozen waves, tortuous folds, in general, really resembling "heaps of giant intestines or bundles of twisted ropes" (). The formation of such a microrelief is characteristic of lavas with a high temperature and a relatively low content of volatile components.

The release of gases from a lava flow may have the character of an explosion. In these cases, slag is piled up in the form of a cone on the surface of the flow. Such forms are called forge. Sometimes they look like pillars up to several meters high. With a calmer and more prolonged release of gases and cracks in the slag, so-called fumaroles. A number of products of fumarole release condense under atmospheric conditions, and crater-like elevations, composed of condensation products, form around the place where gases escape.

With fissure and areal outpourings of lavas, vast spaces are, as it were, filled with lava. Iceland is a classic country of fissure eruptions. Here, the vast majority of volcanoes and lava flows are confined to a depression that cuts the island from the southwest and northeast (the so-called Great Graben of Iceland). Here you can see lava sheets stretched along the faults, as well as gaping cracks, not yet completely filled with lavas. Fissure volcanism is also characteristic of the Armenian Highlands. More recently, fissure eruptions have taken place on the North Island of New Zealand.

The volume of lava flows erupted from cracks in the Great Graben of Iceland reaches 10-12 cubic meters. km. Grandiose areal outpourings occurred in the recent past in British Columbia, on the Deccan Plateau, in Southern Patagonia. Merged lava flows of different ages form here continuous plateaus with an area of ​​up to several tens and hundreds of thousands of square kilometers. So the lava plateau of Colombia has an area of ​​​​more than 500 thousand square kilometers, and the thickness of the lavas composing it reaches 1100-

1800 m. Lavas filled all the negative forms of the previous relief, causing its almost perfect alignment. At present, the height of the plateau is from 400 to 1800 m. The valleys of numerous rivers deeply cut into its surface. Blocky microrelief, cinder cones, lava caves and troughs have been preserved on the youngest lava covers.

During underwater volcanic eruptions, the surface of erupted magmatic flows cools rapidly. Significant hydrostatic pressure of the water column prevents explosive processes. As a result, a kind of microrelief is formed. sharoiformes, or pillow, lava.

Lava outpourings not only form specific landforms, but can significantly affect an already existing relief. So, lava flows can affect the river network, cause its restructuring. Blocking the river valleys, they contribute to catastrophic floods or the drying up of the area; the loss of its streams. Penetrating to the seashore and solidifying here, lava flows change the outlines of the coastline and form a special morphological type of sea coasts.

The outpouring of lavas and the ejection of pyroclastic material inevitably causes the formation of a mass deficit in the bowels of the Earth. The latter causes rapid subsidence of parts of the earth's surface. In some cases, the beginning of the eruption is preceded by a noticeable uplift of the terrain. For example, before the eruption of the Usu volcano on the island of Hokkaido, a large fault formed, along which a surface area of ​​about 3 km2 rose by 155 m in three months, and after the eruption, it lowered by 95 m.

Speaking about the relief-forming role of effusive magmatism, it should be noted that during volcanic eruptions, sudden and very fast changes in the relief and the general state of the surrounding area can occur. Such changes are especially great during explosive-type eruptions. For example, during the eruption of the Krakatau volcano in the Sunda Strait in 1883, which had the character of a series of explosions, most of the island was destroyed, and sea depths of up to 270 m formed at this place. The explosion of the volcano caused the formation of a giant wave - a tsunami that hit the coast of Java and Sumatra. It caused great damage to the coastal regions of the islands, leading to the death of tens of thousands of inhabitants. Another example of this kind is the eruption of the Katmai volcano in Alaska in 1912. Before the eruption, the Katmai volcano had the form of a regular cone 2286 m high. During the eruption, the entire upper part of the cone was destroyed by explosions and a caldera up to 4 km in diameter and up to 1100 m depth.

The volcanic relief is further exposed to exogenous processes, leading to the formation of peculiar volcanic landscapes.

As is known, the craters and summit parts of many large volcanoes are centers of mountain glaciation. Since the glacial landforms formed here do not have any fundamental features, they are not specially considered. Fluvial forms of volcanic regions have their own specifics. melt water, mud flows, which are often formed during volcanic eruptions, atmospheric waters significantly affect the slopes of volcanoes, especially those in the structure of which the main role belongs to pyroclastic material. In this case, a radial system of the ravine network is formed - the so-called barrancos. These are deep erosion furrows, diverging, as it were, along the radii from the top of the volcano (see - Fig. 17).

Barrancos should be distinguished from furrows plowed in the loose cover of ash and lapilli by large blocks thrown out during the eruption. Such formations are often called scars. Sharrs, as original linear depressions, can then be transformed into erosion furrows. There is an opinion that a significant part of the barrancos was founded on the former sharras.

The general pattern of the river network in volcanic regions also often has a radial character. Other distinctive features of river valleys in volcanic regions are waterfalls and rapids formed as a result of rivers crossing solidified lava flows or traps, as well as dam lakes or lake-like valley extensions in place of drained lakes that occur when a river is blocked by a lava flow. In places of accumulation of ash, as well as on lava covers, due to the high permeability of rocks over vast areas, there may be no watercourses at all. Such areas have the appearance of rocky deserts.

Many volcanic regions are characterized by outlets of pressure hot waters called geysers. Hot deep waters contain many dissolved substances that precipitate when the waters cool. Therefore, the places where hot springs come out are surrounded by sintered, often bizarrely shaped terraces. Geysers and their accompanying terraces are widely known in Yellowstone Park in the USA, in Kamchatka (Valley of Geysers), in New Zealand, and in Iceland.

In volcanic regions, there are also specific forms of weathering and denudation preparation. Thus, for example, thick basalt covers or flows of basalt, less often andesitic, lava, when cooled and under the influence of atmospheric agents, are broken by cracks into columnar units. Quite often, the individual pieces are multifaceted pillars that look very impressive in outcrops. The outcrops of cracks on the surface of the lava cover form a characteristic polygonal microrelief. Such spaces of lava exits, divided by a system of polygons - hexagons or pentagons, are called "bridge giants".

During prolonged denudation of the volcanic relief, accumulations of pyroclastic material are destroyed first of all. More resistant lava and other igneous formations

exposed to preparation by exogenous agents. characteristic forms preparations are mentioned above dikes, as well as necks(prepared lava plugs solidified in the crater of a volcano).

Deep erosional dissection and slope denudation can lead to the separation of the lava plateau into separate plateau-like uplands, sometimes far apart from each other. Such residual forms are called Meuse(singular - mesa).

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