Characteristics of personality orientation
Personal orientation is a set of stable motives, views, beliefs, needs and aspirations that orient a person towards certain behavior and activities, and the achievement of relatively complex life goals. Orientation is always socially conditioned and formed in ontogenesis in the process of training and education, acts as a personality trait, manifested in ideological, professional orientation, in activities related to personal hobbies, doing something in free time from the main activity. In all these types of human activity, direction is manifested in the characteristics of the individual’s interests: the goals that a person sets for himself, the needs, preferences and attitudes carried out in drives, desires, inclinations, ideals, etc.
Directional forms:
Needs, motives
goal - the desired and imagined result of a specific activity of a person or group of people
ideal - an image that is the embodiment of perfection and an example of the highest goal in the aspirations of the individual
conviction is the highest form of personality orientation, manifested in the conscious need to act in accordance with one’s value orientations against the background of emotional experiences and volitional aspirations
attitude - an individual’s readiness for a certain activity, which is actualized in the current situation. It manifests itself in a stable predisposition to a certain perception, comprehension and behavior of an individual. An attitude expresses a person’s position, his views, value orientations in relation to various facts of everyday life, social life and professional activity. It can be positive, negative or neutral.
Interest is a mental state that provides direction to the Personality. Interest, like motive, arises in conditions of information deficiency, when a person does not receive enough knowledge that he would like to have.
worldview - a system of views and ideas about the world, a person’s relationship to society, nature, and himself
Characteristics of personality orientation
- Directional level– this is the ratio of higher and lower needs; the higher the level of focus, the more mature and spiritually rich the personality.
- Breadth of focus characterized by the diversity of its main components and has a decisive influence on the richness of the inner world and the versatility of the individual.
- Directional intensity– this is the degree of awareness of needs and motives: low intensity of orientation characterizes orientation as a system of unconscious drives, high intensity - as a system of fundamental beliefs.
- Directional stability is determined by the constancy and consistency of its individual components; the integrity of the individual depends on the stability of the orientation.
- Directional Effectiveness- this is the degree of perseverance of the individual in realizing goals, motives, etc., which determines the activity of the individual’s life position.
There are three main types of personality orientation: personal, collectivistic and business.
Personal orientation is created by the predominance of motives for one’s own well-being, the desire for personal superiority, and prestige. Such a person is most often busy with himself, with his feelings and experiences and reacts little to the needs of the people around him. He sees work, first of all, as an opportunity to satisfy his own aspirations, regardless of the interests of other employees. It has been established that individuals with a self-directed personality have the following character traits:
– more preoccupied with themselves and their feelings, problems
– make unfounded and hasty conclusions about other people, also behave in discussions
– trying to impose their will on the group
– those around them do not feel free in their presence
Orientation towards mutual actions - occurs when a person’s actions are determined by the need for communication, the desire to maintain good relationships with fellow workers and students. Such a person shows interest in joint activities, although he may not contribute to the successful completion of the task; often his actions even make it difficult to complete the group task and his actual assistance may be minimal. People with a focus on mutual action:
- avoid direct solution to the problem
– yield to group pressure
– do not express original ideas and it is not easy to understand what such a person wants to express
– do not take leadership when it comes to choosing tasks
Business orientation - reflects the predominance of motives generated by the activity itself, passion for the process of activity, a selfless desire for knowledge, mastering new skills and abilities. Typically, such a person seeks cooperation and achieves the greatest productivity of the group, and therefore tries to prove a point of view that he considers useful for completing the task. Business-oriented people:
– help individual group members express their thoughts
– support the group to achieve its goal
– express their thoughts and considerations easily and clearly
– take the lead when it comes to choosing a task
– do not shy away from directly solving the problem
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Platforms are relatively stable areas of the earth's crust. They develop on the site of consolidated folded structures that arose during the closure of geosynclines. These are vast, predominantly flat areas of the earth's crust, often of irregular polygonal shape. This shape is determined by large marginal faults that separate the platforms from the adjacent mobile geosynclinal areas. Examples in Russia are the Russian (East European) and Siberian platforms. The platforms are characterized by the following features.
In the structure of the platform, there are two main structural tiers - lower and upper. The lower stage was formed during the geosynclinal (pre-platform) stage of development and consists of highly dislocated metamorphosed rocks, penetrated by intrusions and deep faults. It is called the foundation, folded foundation or platform base. The upper tier is a sedimentary platform cover composed of calmly lying sedimentary rocks. In some places the foundation protrudes to the surface. Such sections of platforms are called shields. Sections of platforms on which the foundation is submerged to depth and covered everywhere with sedimentary cover are called slabs.
Relatively weak and slow, small amplitude, vertical oscillatory movements of the earth's crust. In this case, movements of one sign - slow sagging or slow lifting - cover large areas of platforms and can change over time. Periodic transgressions and regressions of sea basins are associated with the oscillatory nature of tectonic movements in the development of platforms. Some parts of the platforms are still flooded by epicontinental seas - the Baltic, Northern, etc.
The comparatively small thickness of sedimentary rocks of the platform cover is usually up to 2-4 km, i.e. several times less than in geosynclinal areas, which changes gradually.
The composition of sedimentary rocks is more or less uniform. In epicontinental platform seas, either carbonate rocks accumulate - limestones, dolomites, or shallow sandy-clayey sediments. From mineral resources, sedimentary iron and manganese ores, phosphorites, bauxites, etc. were formed here in places. During periods of regression, continental sediments accumulated on the site of former seas - lacustrine, alluvial, swamp, and in arid climates - aeolian and lagoonal. These stages of continental development are associated with the formation of iron ores (in swamps and lakes), coal and salts.
Horizontal or almost horizontal occurrence of layers of sedimentary rocks, complicated in places by isolated gently sloping masonry (discontinuous folding). The largest structural elements of platforms - syneclises - are huge flat isometric depressions - troughs, occupying vast areas, reaching hundreds and even thousands of kilometers in diameter. They are distinguished by a very gentle dip of the layers - a few meters per kilometer, which corresponds to an angle of inclination of several minutes. An example is the Moscow syneclise with a central part near Moscow. Its cross section (from north to south) reaches 1300 km, and the fall of the layers is 2-2.5 m/km. Large, gentle elevations of platforms are called anteclises. An example of them are the Belarusian and Voronezh anteclises. In addition to syneclises and anteclises, within the platforms there are jelly-shaped tectonic depressions, linearly oriented and limited by deep faults, stretching for many hundreds of kilometers with a width from tens to 100-200 km. These depressions were called aulacogens by N.S. Shatsky (Greek “aulacon” - furrow). They exhibit increased tectonic activity and large thicknesses of sedimentary rocks (for example, the Dnieper-Donets depression). Of the smaller folded forms, shafts, brachyfolds, domes, and flexures are developed.
When determining the volume and intensity of training loads that provide the optimal adaptation effect, two ways are possible. First -- intensive path, consisting in a further increase in the total volumes of training loads. On this path, the opportunities for further sports growth for highly qualified athletes are now practically exhausted. The second option is more promising from the point of view of further progress in world sports - way to intensify training activities. On this path, while maintaining the already achieved (almost maximum) volumes of training load, a combination of high-intensity, developmental loads with supporting loads is proposed, preserving the achieved level of functioning of the necessary systems, which creates the best conditions for achieving sports success.
The existing experience in training the strongest athletes shows the possibility of an annual increase in the total volume of the training load by 20%. In young athletes this increase is possible by 40 - 50 % depending on the type of athletics and its individual characteristics, adapt to it. Naturally, the intensity of the exercises increases, which is expressed in an increase in the volume of load performed at maximum and near-maximum 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 of special exercises. One of the indicators of the intensity of sports activities is the increase in the number of competitions.
Modern ideas about the relationship between the volume and intensity of training loads in a year-round cycle suggest constructing the educational and training process in such a way that, without contrasting volume with intensity, periodically simulate the load and tension characteristic of competitions. Year-round use of special training and the main type (main distance, main apparatus, personal jump, etc.) is 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 mandatory variability of loads, based on the laws of adaptation, then highly qualified athletes will be able to show good results every 1.5 - 2 months.
An organic part of any exercise that affects the load is properly organized rest. A rational alternation of work and rest underlies all sports training and extends to repeated exposure to load in one session of the training day, throughout the week, month, year and years.
Repeated use of training and competitive loads is organically connected with the time intervals between them and with recovery processes. The number of repetitions, exercises, the nature and duration of rest intervals depend on the tasks, means and methods of preparation, as well as on the characteristics of the types of athletics, the athlete’s level of preparedness and external conditions.
In all cases, it is important to establish rest breaks between individual exercises and classes that, 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 rest It happens passive And active. In between exercises that require precise movements and great concentration, active rest gives good results in restoring performance. For example, during training in complex types of athletics (hurdle running, high jumping and pole vaulting, hammer and javelin throwing), slow running, walking or short sports and outdoor games are used for relaxation. Conversely, during cyclic exercises, you can offer short-term performance of movements with complex coordination for relaxation.
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 technique they should be carried out daily, and then 3-4 times a week. If the break is 48 hours, this leads to a decrease in the level of mastered lesson material by up to 25%, primarily due to dulling of kinesthetic sensitivity.
The duration of rest between loads can be divided into four types: 1) full (ordinary); 2) incomplete (supercompensatory); 3) shortened (hard); 4) long-lasting (soft). By varying rest intervals with the same volume (or intensity) of load, you can achieve different results in the development of motor qualities. For example, in cyclic types of athletics, incomplete rest ensures the development of endurance to a greater extent, full rest ensures the development of speed, short rest ensures speed endurance, and a long rest ensures the restoration of performance after a strenuous part of the training or after overwork (overtraining).
The quantitative and qualitative components of the load are organically interrelated. But depending on the structure of the athlete’s training process (tasks, means, methods, load level, etc.), the relationships between them are different, and the adaptation processes are accordingly 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 exercises is the economization of the body functions of athletes, ensuring the same work is performed with less energy resources.
Doing any physical exercise takes time. And no matter how small it may be, this is already a certain amount of work, which constitutes the volume of 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 a thrower is the volume of a specific load, and the effectiveness of these throws is its intensity.
The integral indicator of changes in the body quite accurately determines the level of training load - heart rate(heart rate). To do this, measure the pulse during exercise, after it and during the rest period. By 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 educational and training process.
Table 2 gives an idea of how loads in sports can be classified according to the direction of their impact, which is based on taking into account the ways in which energy is supplied to work. Under the same conditions, it is the direction of the load, which determines the degree of participation of various organs and functions in the work performed, that indicates the degree of their inhibition and the duration of recovery.
Table 2.
By size, the load can be divided into maximum, large, medium and small. is within the athlete's capabilities. Its criteria are the athlete’s inability to continue performing the proposed task. The pulse reaches a value of 180 or more beats per minute (bpm). If an athlete tries to cross this limit by force of will, the load becomes prohibitive and can lead to overtraining of the athlete.
in terms of the number of exercises and intensity of movements it is 70-80% of the maximum, i.e. it makes it possible to continue the action against the background of fatigue. Heart rate readings 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 training increases, the load, which was initially considered as maximum, at subsequent stages becomes large or medium, etc. This is especially true for such a load component as intensity. The higher the intensity of the exercise performed, the longer it is, the greater the costs for the athlete’s body, the greater the load on his psyche. It is also 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 less 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 types (middle and long distance running, race walking), the main thing is a high average level of movement speed.
In order to more effectively perform exercises by an athlete, with a given training effort, intensity zones should be determined as the ratio of a given value of training or competitive stress to the maximum possible data of the athlete. Table 3 presents 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 the development zone. By applying a training load in the 90-100% zones, there is an impact on the development of speed; it should be included in almost every training session and structured in such a way that during each session the load is applied in all intensity zones, with its optimal ratio. The training load in the zones of 50-80% of the maximum mainly solves the problems of special warm-up and recovery, which contributes to the favorable course of the entire training process.
The result in athletics depends on a high level of endurance and dictates a certain selectivity of training effects, which are provided by aerobic (with oxygen), anaerobic (without oxygen) and aerobic-anaerobic (mixed) processes in the athlete’s body. In Table 4, intensity zones are distributed according to heart rate indicators during a particular training work when developing endurance.
Table 4.
When using the aerobic training regime, 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 is possible with a heart rate of 190 beats per minute or more.
Monitoring your heart rate during recovery is very important in determining the adequacy of the proposed loads. primary goal heart rate control is to determine the training tension, to comply with the main requirement of training - to avoid excessive overexertion, preventing cases of overwork and overtraining. If an athlete’s heart rate after a load does not recover within a certain time to the desired level (for example, the heart rate 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 training work (quantity, pace) must be reduced or stopped.
During 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 heart rate of 100-120 beats/min. When developing speed endurance, you should focus on restoring your heart rate to 120-140 beats/min 1-3 minutes after completing the work, and between series the pulse should be restored to 100-120 beats/min within 2-5 minutes. When recovering from a stressful workout (control run, estimation), the pulse should reach 100-120 beats/min for 4-10 minutes. Repeated performance 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 stopping training work should be considered a pulse over 120 beats/min after 5-10 minutes of rest.
The levels of heart rate recovery are somewhat individual and can be determined by age, the state of anaerobic functions, and genetic character. They can be between 108 --132 beats/min. The following factors also affect the recovery processes: the athlete is out of shape, the 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 under high training loads. With a large volume 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 and start working again. With a small amount of work with 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 effectively as at the beginning. When “acute”, high-intensity impact work is performed, during the recovery (rest) period, the heart rate should reach 90-100 beats/min before repeating the proposed load.
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 (they determine marine transgressions and regressions) and 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, are known to be the root cause of climate change on the Earth's surface. Consequently, vertical movements not only have a direct effect on the relief, but also indirectly, through climate, the influence of which on the relief was discussed above (Chapter 4).
RELIEF FORMING ROLE OF THE LATEST TECTONIC MOVEMENTS OF THE EARTH'S CRUST
In previous chapters, we talked about 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 the latest tectonic
Rice. 12. Scheme of the latest (Neogene-Quaternary) tectonic movements on the territory of the USSR (but significantly simplified): / - areas of very weakly expressed positive movements; 2-areas of weakly expressed linear positive movements; 3 - areas of intense arched uplifts; 4 - areas of weakly expressed linear uplifts and downfalls; 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-border of areas of strong earthquakes (magnitude 7 or more); c - boundary of manifestation of Neogene-Quaternary volcanism; 9 - border of distribution of existing
dviwives, by which most researchers understand the movements that took place in Neogene-Quaternary times. This is evidenced quite convincingly, for example, by a comparison of the hypsometric map of the USSR and the map of the latest tectonic movements (Fig. 12). Thus, areas with weakly expressed vertical positive tectonic movements in the relief correspond to plains, low plateaus and plateaus with a thin cover of Quaternary sediments: the East European Plain, a significant part of the West Siberian Lowland, the Ustyurt Plateau, the Central Siberian Plateau.
Areas of intense tectonic subsidence, as a rule, correspond to lowlands with a thick layer of Neogene-Quaternary sediments: the Caspian Lowland, a significant part of the Turan Lowland, the North Siberian Lowland, the Kolyma Lowland, etc. Areas of intense, predominantly positive tectonic movements correspond to the mountains: Caucasus, Pamir , Tien Shan, mountains of the Baikal region 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 different orders. Through the differentiation of the topographic surface, the latest tectonic movements control the location on the Earth's surface of areas of demolition and accumulation and, as a consequence of this, areas with a predominance of denudation (worked out) and accumulative relief. The speed, amplitude and contrast of new movements significantly influence the intensity of the manifestation of exogenous processes and are also reflected in the morphology and morphometry of the relief.
The expression in modern relief of structures created by neotectonic movements depends on the type and nature of neotectonic movements, the lithology of the deformed strata and specific physiographic conditions. Some structures are directly reflected in the relief, in place of others an inverted relief is formed, in the place of others - 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 tend to find direct expression in relief.
Landforms that owe their origin to neotectonic structures are called morphostructures. Currently, there is no single interpretation of the term “morphostructure” either in relation to the scale of forms or in relation to 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 arose in place of a geological structure, others - only direct relief. The latter's point of view is perhaps more correct. We will call morphostructures landforms of different scales, the morphological appearance of which largely corresponds to the types of geological structures that created them.
The data currently available from geology and geomorphology indicate that the earth’s crust experiences deformations almost everywhere and of a different nature: oscillatory, fold-forming, and rupture-forming. For example, the territory of Fennoscandia and a significant part of North America adjacent to Hudson Bay are currently experiencing uplift. The rates of uplift in these areas are very significant. In Fennoscandia they amount to 10 mm per year (sea level marks made in the 18th century on the shores of the Gulf of Bothnia are raised above the modern level by 1.5-2.0 m).
The shores of the North Sea within Holland and its neighboring regions are sinking, forcing residents to build dams to protect the territory from the advance of the sea.
Areas of Alpine folding and modern geosynclinal belts experience intense tectonic movements. According to available data, the Alps rose by 3-4 km during the Neogene-Quaternary time, the Caucasus and the Himalayas rose by 2-3 km only during the Quaternary time, and the Pamirs by 5 km. Against the background of uplifts, individual areas within the areas of Alpine folding experience intense subsidence. Thus, against the backdrop of the rise of the Greater and Lesser Caucasus, the Kura-Araks lowland 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 - the Late Baku Sea, the level of which was located at an absolute height of 10-12 m, are currently traced within the southeastern pericline of the Greater Caucasus and on the slopes of the Talysh Mountains at absolute levels of +200-300 m, and within The Kura-Araks lowland was penetrated 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 denudation surfaces; c) deeply submerged or highly elevated coral reefs; d) submerged marine coastal forms and some underwater karst springs, 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 the river sawing through a tectonic high that occurs along its path - an anticlinal fold or block (Fig. 13),
The manifestation of neotectonic movements can also be judged by a number of indirect signs. Fluvial relief forms react sensitively to them. Thus, areas experiencing tectonic uplifts are usually characterized by an increase in density and depth
erosional dissection compared to tectonically stable territories or experiencing immersion. The morphological appearance of erosion forms also changes in such areas: valleys usually become narrower, slopes become steeper, changes in the longitudinal profile of rivers and sharp changes in the direction of their flow in plan are observed, which cannot be explained by other reasons, etc. Thus, there is a close connection between the nature and the intensity of recent tectonic movements and relief morphology. This connection allows the widespread 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 ocean area 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 dvimarriages, under which, according to
Understand the movements that have manifested themselves V historical time and those 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 during 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. Landforms associated with intrusive magmatism can be either the result of the direct influence of igneous bodies (batholiths, laccoliths, etc.), or a consequence 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 anticlinoriums. They form large positive forms of relief, the surface of which is complicated by smaller forms, which owe their appearance to the influence of certain exogenous agents, depending on specific physical and geographical conditions.
Examples of fairly large granite batholiths on the territory of the USSR are the massif in the western part of the Zeravshan Range in Central Asia (Fig. 14), and a large massif in the Konguro-Alagez Range in Transcaucasia.
Laccoliths occur alone or in groups and are often expressed V relief with positive forms in the form of domes or “loaves”. The laccoliths of the North Caucasus are well known
Rice. 15. Laccoliths of Mineralnye Vody, Northern Caucasus (fig.)
(Fig. 15) in the area of the city of Mineralnye Vody: mountains Beshtau, Lysaya, Zheleznaya, Zmeinaya, etc. Typical laccoliths, well expressed in the relief, are also known in the Crimea (mountains Ayu-Dag, Kastel).
From laccoliths and other intrusive bodies vein-like branches called apophyses. They cut the host rocks in different directions. Prepared apophyses on the earth's surface form narrow, vertical or steeply falling bodies, reminiscent of collapsing walls (Fig. 16.5- B). Layered intrusions are expressed in the relief in the form of steps, similar to the structural steps formed as a result of selective denudation in sedimentary rocks (Fig. 16, L-L). Prepared bed intrusions are widespread within the Central Siberian Plateau, where they are associated with the intrusion of rocks trap formation 1.
Igneous bodies complicate folded structures and their reflection in the relief. Formations associated with the activity of effusive magmatism, or volcanism, which creates a completely unique relief, are clearly reflected in the relief. Volcanism is the 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 outlets, eruptions are distinguished areal, linear And central. Area eruptions led to the formation of extensive lava plateaus. The most famous of them are the lava plateaus of British Columbia and the Deccan (India).
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Rice. 16. Prepared intrusive bodies: A-A- layered 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 eruption, in which magma flows from the subsurface to the surface at certain “points”, usually located at the intersection of two or more faults. The magma enters through a narrow feeding channel. The eruption products are deposited periclinally (i.e., falling in all directions) relative to the exit of the feeding channel to the surface. Therefore, usually a more or less significant accumulative form, the volcano itself, rises above the center of the eruption (Fig. 17).
In a volcanic process, two stages can almost always be distinguished - explosive, or explosive, and eruptive, or the stage of release and accumulation of volcanic products. A channel-like path to the surface is made 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 in a funnel-shaped manner, forming a negative relief shape - a crater. Subsequent lava outpouring and accumulation of pyroclastic material occurs around 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- a negative landform, usually funnel-shaped or cylindrical, resulting from a volcanic explosion. There are almost no volcanic accumulations along the edges of such a depression. All currently known maars are inactive, relict formations. A large number of maars are described in the Eifel region in Germany, in the Massif Central in France. Most maars in humid climates fill with water and turn into lakes. The dimensions of the maars are from 200 m to 3.5 km in diameter with 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 buildings are stratovolcanoes. The structure of stratovolcanoes involves both lava layers and layers of pyroclastic material. Many stratovolcanoes have an almost regular conical shape: Fujiyama in Japan, Klyuchevskaya and Kronotskaya Solka in Kamchatka, Popocatepetl 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 in diameter are known. At the bottom of the calderas the relief is relatively flat; 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 volcano's crater by strong explosions. In some cases, the caldera has a collapsed origin. In extinct volcanoes, caldera expansion may also be associated with the activity of exogenous agents.
A unique relief is formed by the 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. If the viscosity is very high, it can harden in the vent, forming a giant “lava column” or “lava finger,” as was the case, for example, during the eruption of Mount Pelé in Martinique in 1902. Typically, a lava flow looks like a flattened shaft extending down the slope , with a very clearly defined swelling at its end. Basaltic lavas can produce long flows that spread over many kilometers or 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 that emit products of acidic or intermediate composition, a much larger part by volume is pyroclastic rather than lava material.
As the lava flow hardens, it is first covered with a crust of slag. If the crust breaks through 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 a cave roof collapses, it turns into a negative surface landform - Lavogutter Trenches are very characteristic of the volcanic landscapes of Kamchatka.
The surface of the frozen stream acquires a unique microrelief. The most common are two types of surface microrelief of lava flows: a) blocky microrelief and b) gut-shaped lava. Blocky lava flows are a chaotic accumulation of angular or melted blocks with numerous failures and grottoes. Such blocky forms arise at a high content of gases in the composition of lavas and at a relatively low temperature of the flow. Gut-shaped lavas are distinguished by a bizarre combination of frozen waves, winding folds, on the whole really reminiscent of “piles of giant guts or bundles of twisted ropes” (). The formation of such a microrelief is typical for lavas with high temperatures and a relatively low content of volatile components.
The release of gases from a lava flow can be explosive. In these cases, a cone-shaped accumulation of slag occurs on the flow surface. Such forms are called gornito. Sometimes they look like pillars up to several meters high. With a quieter and longer-lasting release of gases and cracks in the slag, so-called fumaroles. A number of fumarole emission products condense under atmospheric conditions, and crater-shaped elevations composed of condensation products form around the place where the gases escape.
During fissure and areal outpourings of lavas, vast spaces appear to be filled with lava. Iceland is a classic country for fissure eruptions. Here, the vast majority of volcanoes and lava flows are confined to a depression that cuts the island from the southwest to the northeast (the so-called Great Graben of Iceland). Here you can see lava sheets stretched along the faults, as well as gaping cracks that are not yet completely filled with lavas. Fissure volcanism is also characteristic of the Armenian Highlands. Relatively recently, fissure eruptions took place on the North Island of New Zealand.
The volume of lava flows that erupted from cracks in the Great Graben of Iceland reaches 10-12 cubic meters. km. Enormous 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. Thus, 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. Currently, the height of the plateau is from 400 to 1800 m. The valleys of numerous rivers cut deeply into its surface. The youngest lava covers here preserve blocky microrelief, cinder cones, lava caves and trenches.
During underwater volcanic eruptions, the surface of the erupted magma flows quickly cools. Significant hydrostatic pressure of the water column prevents explosive processes. As a result, a unique microrelief is formed. sharooform, or cushion, lava
Lava outpourings not only form specific relief forms, but can significantly influence existing relief. Thus, lava flows can affect the river network and cause its restructuring. By blocking river valleys, they contribute to catastrophic floods or drying out of the area; loss of watercourses. Penetrating to the seashore and solidifying here, lava flows change the contours of the coastline and form a special morphological type of sea coasts.
Lava outpourings and the release of pyroclastic material inevitably cause the formation of a mass deficit in the bowels of the Earth. The latter causes rapid subsidence of sections of the earth's surface. In some cases, the onset of an eruption is preceded by a noticeable rise in 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 dropped by 95 m.
Speaking about the relief-forming role of effusive magmatism, it should be noted that during volcanic eruptions sudden and very rapid changes in the relief and general condition of the surrounding area can occur. Such changes are especially great during explosive eruptions. For example, during the eruption of the Krakatoa volcano in the Sunda Strait in 1883, which was a series of explosions, most of the island was destroyed, and sea depths of up to 270 m were formed in this place. The explosion of the volcano caused the formation of a giant wave - a tsunami, which hit the shores of Java and Sumatra. It caused enormous damage to the coastal areas 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 Kat-mai volcano looked like a regular cone with a height of 2286 m. During the eruption, the entire upper part of the cone was destroyed by explosions and a caldera was formed 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 unique 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 specifically considered. Fluvial forms of volcanic areas have their own specifics. Melt waters, mud flows, often formed during volcanic eruptions, and atmospheric waters significantly affect the slopes of volcanoes, especially those in the structure of which the main role is played by pyroclastic material. In this case, a radial system of a gully network is formed - the so-called Barrancos. These are deep erosion grooves, radiating as if 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 sharrams. Sharras, as original linear depressions, can then be transformed into erosional furrows. There is an opinion that a significant part of the barrancos is based on former sharras.
The general pattern of the river network in volcanic areas is also often radial. Other distinctive features of river valleys in volcanic areas are waterfalls and rapids formed as a result of rivers crossing solidified lava flows or traps, as well as dam lakes or lake-like extensions of valleys in place of drained lakes that occur when a lava flow dams a river. In places where ash accumulates, as well as on lava sheets, due to the high water permeability of rocks, there may be no watercourses at all over large areas. Such areas have the appearance of rocky deserts.
Many volcanic areas are characterized by the release of pressurized hot water, called geysers. Hot deep waters contain many dissolved substances that precipitate when the waters cool. Therefore, hot spring outlets are surrounded by sintered, often bizarrely shaped terraces. Geysers and the accompanying terraces in Yellowstone Park in the USA, Kamchatka (Valley of Geysers), New Zealand, and Iceland are widely known.
In volcanic areas, specific forms of weathering and denudation are also found. For example, thick basaltic covers or flows of basaltic, less often andesitic, lava, when cooling and under the influence of atmospheric agents, are broken by cracks into columnar units. Individuals often appear as multifaceted pillars, which 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 outcrops, 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. More persistent lava and other igneous formations
exposed to exogenous agents. The characteristic forms of preparation are those mentioned above dykes, and nekki(prepared lava plugs frozen in the crater of a volcano).
Deep erosional dissection and slope denudation can lead to the division of the lava plateau into separate plateau-like hills, sometimes far apart from each other. Such remnant forms are called Meuse(singular - mesa).
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As a result of the long history of geological development on the territory of Russia, the main types of g e o t e c t u r- plain-platform areas and large orogenic mobile belts. However, within the same geotextures, completely different topography is often common (low basement plains of Karelia and the Aldan Highlands on the shields of ancient platforms; low Ural Mountains and high-mountain Altai within the Ural-Mongolian belt, etc.); on the contrary, similar relief can form within different geotextures (high-mountain Caucasus and Altai). This is due to the great influence on the modern relief of neotectonic movements that began in the Oligocene (Upper Paleogene) and continue to the present day.
After a period of relative tectonic calm at the beginning of the Cenozoic, when low plains predominated and practically no mountains remained (only in the area of Mesozoic folding, small hills and low mountains apparently remained in some places), vast areas of Western Siberia and the south of the East European Plain were covered with waters shallow sea basins. In the Oligocene, a new period of tectonic activation began - the neotectonic stage, which led to a radical restructuring of the relief.
The latest tectonic movements and morphostructures. Neotectonics, or the latest tectonic movements, V.A. Obruchev defined it as movements of the earth's crust that created the modern relief. It is with the latest (Neogene-Quaternary) movements that the formation and placement of morphostructures on the territory of Russia are associated - large relief forms that arose as a result of the interaction of endogenous and exogenous processes with the leading role of the former.
The latest tectonic movements are associated with the interaction of modern lithospheric plates (see Fig. 6), along the margins of which they manifested themselves most actively. The amplitude of Neogene-Quaternary movements in the marginal parts reached several kilometers (from 4 km in Transbaikalia and Kamchatka to 10-12 km in the Caucasus), and in the internal regions of the plates it was measured in tens, less often - hundreds of meters. In the marginal parts, sharply differentiated movements prevailed: uplifts of large amplitude were replaced by equally grandiose subsidences in nearby areas. In the central parts of lithospheric plates, movements of the same sign occurred over large areas.
Mountains arose in the immediate contact zone of various lithospheric plates. All mountains currently existing on the territory of Russia are the product of recent tectonic movements, i.e. they all arose in Neogene-Quaternary times and, therefore, are of the same age. But the morphostructures of these mountains are very different depending on the method of their origin, and it is associated with the position of the mountains within various tectonic structures."
Where mountains arose on the young oceanic or transitional crust of the marginal parts of plates with a thick cover of sedimentary rocks crumpled into folds (areas of Alpine and Pacific folds), young folded mountains formed (Great Caucasus, Sakhalin ranges) sometimes with sections of volcanic mountains (Kamchatka ranges ). The mountain ranges here are linearly elongated along the edge of the plate. In those places where, at the boundaries of the lithospheric plate, there were territories that had previously experienced folding movements and turned into plains on a folded foundation, with a rigid continental crust that could not be compressed into folds (areas of pre-Paleozoic and Paleozoic folding), the formation of mountains proceeded differently. Here, under lateral pressure arising when the lithospheric plates approached each other, the rigid foundation was broken by deep faults into separate blocks (blocks), some of which were squeezed upward during further movement, others downward. This is how mountains are reborn in place of plains. These mountains are called regenerated block mountains, or folded block mountains. All the mountains of southern Siberia, the Urals, and Tien Shan have been restored.
In areas of Mesozoic folding, where by the time intense movements began, the mountains might not have been completely destroyed, where areas of low-mountain or small-hill relief were preserved, the orographic pattern of the mountains might not change or change only partially, but the height of the mountains increased. Such mountains are called rejuvenated block-folded. They reveal features of both folded and block mountains, with a predominance of one or the other. The rejuvenated ones include Sikhote-Alin, the mountains of the North-East and partly the Amur region. The internal parts of the Eurasian lithospheric plate belong to areas of weak and very weak uplifts and predominantly weak and moderate subsidence. Only the Caspian lowland and the southern part of the Scythian plate sank intensively. Most of the territory of Western Siberia experienced weak subsidence (up to 100 m), and only in the north the subsidence was moderate (up to 300 m or more). The southern and western outskirts of Western Siberia and the large eastern part of the East European Plain were a weakly mobile plain. The largest amplitudes of uplifts on the East European Plain are characteristic of the Central Russian, Volga and Bugulmino-Belebeevskaya uplands (100-200 m). On the Central Siberian Plateau, the amplitude of uplifts was greater. The Yenisei part of the plateau is elevated by 300-500 m, and the Putorana plateau is even 500-1000 m and higher.
The result of recent movements was the morphostructure of the platform plains. On the shields, which had a constant tendency to rise, basement plains (Karelia, the Kola Peninsula), plateaus (Anabar massif) and ridges (Timan, Yenisei, eastern spurs of Donetsk) were formed - hills that have an elongated shape in plan and formed by dislocated rocks of a folded base. On plates where basement rocks are covered by sedimentary cover, accumulative plains, strata plains and plateaus have formed.
Accumulative plains are confined to areas of subsidence in recent times (see Fig. 6 and 7), as a result of which they have a fairly thick cover of Neogene-Quaternary sediments. Accumulative plains include the middle and northern parts of the West Siberian Plain, the Middle Amur Plain, the Caspian Lowland and the north of the Pechora Lowland. Stratified plains and plateaus are the morphostructures of plate sections that have experienced predominant uplifts. When the rocks of the sedimentary cover are monoclinal, inclined stratal plains predominate; when the rocks are subhorizontal, stratal-layered plains and plateaus predominate. Stratified plains are characteristic of most of the East European Plain, the southern and western margins of Western Siberia, and partly of Central Siberia. On the territory of Central Siberia, plateaus are widely represented, both sedimentary (structural - Angaro-Lenskoe, Leno-Aldanskoe, etc.) and volcanic (Putorana, Central Tungusskoe, Syverma, etc.).
Volcanic plateaus are also characteristic of mountainous regions (Eastern Sayan, Vitim Plateau, Eastern Range in Kamchatka, etc.). In the mountains, morphostructures of shields can also be found, and in intermountain basins there can be accumulative and, to a lesser extent, stratified plains (Kuznetsk Basin).
1) from the Gakkel Ridge in the Arctic Ocean through the Chersky Ridge, where the Chukotka-Alaska block of the North American Plate broke away from the Eurasian Plate and is moving away at a speed of 1 cm/year;
2) in the area of the Lake Baikal depression, the Amur Plate broke off from the Eurasian Plate, which rotates counterclockwise and in the Baikal area moves away at a speed of 1-2 mm/year. Over 30 million years, a deep gap appeared here, within which there is a lake;
3) in the Caucasus region, which falls into a seismic belt stretching along the southwestern edge of the Eurasian plate, where it approaches the African-Arabian plate at a speed of 2-4 cm/year.
Earthquakes indicate the existence of deep tectonic stress in these areas, expressed from time to time in the form of powerful tremors and ground vibrations. The last catastrophic earthquake in Russia was the earthquake in the north of Sakhalin in 1995, when the city of Neftegorsk was wiped off the face of the earth.
In the Far East, there are also underwater earthquakes, accompanied by seaquakes and giant destructive tsunami waves.
Platform areas with their flat topography and weak manifestations of neotectonic movements do not experience significant earthquakes. Earthquakes here are extremely rare and manifest themselves in the form of weak vibrations. Thus, the earthquake of 1977 is still remembered by many Muscovites. Then the echo of the Carpathian earthquake reached Moscow. In Moscow, on the 6th to 10th floors, chandeliers swayed and sets of keys jingled in the doors. The strength of this earthquake was 3-4 points.
Not only earthquakes, but also volcanic activity is evidence of the tectonic activity of the territory. Currently, volcanic phenomena in Russia are observed only in Kamchatka and the Kuril Islands.
The Kuril Islands are volcanic ridges, highlands and solitary volcanoes. In total, there are 160 volcanoes in the Kuril Islands, of which about 40 are currently active. The highest of them is the Alaid volcano (2339) on Atlasov Island. In Kamchatka, volcanism gravitates towards the eastern coast of the peninsula, from Cape Lopatki to 56° N, where the northernmost Shiveluch volcano is located.