Tectonics is the science of what? Global tectonics. Tectonics in architecture

Tectonics is a section of geology that studies the structure of the earth's crust and the motion of lithospheric plates. But it is so multifaceted that it plays a significant role in many other sciences about the Earth. Tectonics are used in architecture, geochemistry, seismology, volcanic studies and many other areas.

Science of tectonics

Tectonics is a relatively young science, it studies the motion of lithospheric plates. For the first time, the idea of plate movement is voiced in the theory of continental drift by Alfred Wegener in the 1920s. But its development, it was only in the 60 years of the XX century, after carrying out studies of the relief on the continents and the ocean floor. The material obtained made it possible to take a fresh look at earlier theories. The theory of lithospheric plates appeared as a result of the development of the ideas of the theory of continental drift, the theory of geosynclines and the hypothesis of contractions.

Tectonics is a science that studies the strength and nature of forces that form mountain massifs, crush rocks into folds, stretch the earth's crust. It is the basis of all the geological processes taking place on the planet.

The contraposition hypothesis

The hypothesis of contraction was put forward by the geologist Elie de Beaumont in 1829 at a meeting of the French Academy of Sciences. It explains the processes of mountain building and folding of the earth's crust under the influence of a decrease in the volume of the Earth due to cooling. The hypothesis was based on the ideas of Kant and Laplace about the primary fiery-liquid state of the Earth and its further cooling. Therefore, the processes of mountain building and fold formation were explained as processes of compression of the earth's crust. In the future, cooling down, the Earth reduced its volume and crumpled into folds.

The contraction tectonics, the definition of which confirmed the new doctrine of geosynclines, explained the uneven structure of the earth's crust, became a solid theoretical basis for the further development of science.

Theory of geosynclines

It existed at the turn of the late XIX and early XX centuries. She explains the tectonic processes by cyclic vibrational movements of the earth's crust.

The attention of geologists was drawn to the fact that the rocks can lie horizontally or dislocated. Horizontally occurring rocks were carried to platforms, and dislocated - to folded areas.

According to the theory of geosynclines, at the initial stage, due to active tectonic processes, deflection occurs, and the crust is lowered. This process is accompanied by the demolition of sediments and the formation of a thick layer of sedimentary deposits. Later, the process of mountain formation and appearance of folding occurs. At the expense of the geosynclinal regime comes the platform, which is characterized by insignificant tectonic movements with the formation of a small thickness of sedimentary rocks. The final stage is the stage of the formation of the continent.

Almost 100 years dominated geosynclinal tectonics. The geology of that time was short of factual material, later the accumulated data led to the creation of a new theory.

The theory of lithospheric plates

Tectonics is one of the directions in geology, which formed the basis of the modern theory of the movement of lithospheric plates.

According to the theory of lithospheric plates, part of the earth's crust is lithospheric plates that are in continuous motion. Their movement is relative to each other. In the stretching zones of the earth's crust (mid-oceanic ridges and continental rifts) a new oceanic crust (the spraying zone) is formed. In the zones of immersing the blocks of the earth's crust, the old crust is absorbed, as well as the oceanic subsidence under the continental (subduction zone). Also within the framework of the theory, the reasons for the occurrence of earthquakes, the processes of mountain building and volcanic activity are explained.

The global tectonics of plates includes such a key concept as the geodynamic situation. It is characterized by a combination of geological processes, within the same territory, in a certain period of geological time. For the same geodynamic situation, the same geological processes are characteristic.

The structure of the globe

Tectonics is a section of geology that studies the structure of the planet Earth. The earth in rough approximation has the form of a flattened ellipsoid and consists of several shells (layers).

In the structure of the globe, the following layers are distinguished:

1. Earth's crust.
2. Mantle.
3. Core.

The Earth's crust is the outer solid layer of the Earth, it is separated from the mantle by a boundary called the surface of Mokhorovic.

The mantle, in turn, is divided into upper and lower. The boundary separating the layers of the mantle is the Golitsin layer. The Earth's crust and the upper part of the mantle, before the asthenosphere, are the lithosphere of the Earth.

The nucleus is the center of the globe, separated from the mantle by the Gutenberg boundary. It is divided into a liquid outer and solid inner core, between them there is a transition zone.

The structure of the earth's crust

The science of tectonics has a direct relation to the structure of the earth's crust. Geology studies not only the processes taking place in the depths of the Earth, but also its structure.

The Earth's crust is the upper part of the lithosphere, it is the outer hard shell of the Earth, it is composed of rocks of various physicochemical composition. According to physicochemical parameters there is a subdivision into three layers:

1. Basaltic.
2. Granite-gneiss.
3. Sedimentary.

There is also a division in the structure of the earth's crust. There are four main types of crust:

1. Continental.
2. Oceanic.
3. Subcontinental.
4. Suboceanic.

The continental crust is represented by all three layers, its thickness varies from 35 to 75 km. The upper, sedimentary layer is developed widely, but, as a rule, has a small thickness. The next layer, granite-gneiss, has maximum power. The third layer, basaltic, is composed of metamorphic rocks.

The oceanic crust is represented by two layers - sedimentary and basaltic, its thickness is 5-20 km.

The subcontinental crust, like the continental crust, consists of three layers. The difference is that the thickness of the granite-gneiss layer in the subcontinental crust is much smaller. This type of crust is found on the border of the continent with the ocean, in the area of active volcanism.

The sub-oceanic crust is close to the oceanic crust. The difference is that the thickness of the sedimentary layer can reach 25 km. This type of crust is confined to the deep deflections of the earth's crust (intracontinental seas).

Lithospheric plate

Lithospheric plates are large blocks of the earth's crust that are part of the lithosphere. Plates are able to move relative to each other along the upper part of the mantle - the asthenosphere. The plates are separated from one another by deep-water gutters, mid-ocean ridges and mountain systems. A characteristic feature of lithospheric plates is that they are able to maintain rigidity, shape and structure for a long time.

The tectonics of the Earth indicates that the lithospheric plates are in constant motion. With the passage of time, they change their contours - they can split or grow together. To date, 14 large lithospheric plates have been identified.

Tectonics of lithospheric plates

The process that forms the external appearance of the Earth is directly related to the tectonics of lithospheric plates. The tectonics of the world implies that movement is not of continents, but of lithospheric plates. Facing each other, they form mountain massifs or deep ocean basins. Earthquakes and volcanic eruptions are a consequence of the movement of lithospheric plates. Active geological activity is confined mainly to the edges of these formations.

The movement of lithospheric plates is recorded with the help of satellites, but the nature and mechanism of this process remains a mystery.

Tectonics of the Oceans

In the oceans the processes of destruction and accumulation of precipitation have a slowed down character, therefore tectonic movements are well reflected in the relief. The relief of the bottom has a complicated dissected structure. Tectonic structures formed as a result of vertical motions of the earth's crust and structures obtained due to horizontal movements are distinguished.

The structures of the ocean floor include such forms of relief as the abyssal plains, ocean basins and mid-oceanic ridges. As a rule, a calm tectonic situation is observed in the zone of the basins, tectonic activity of the earth's crust is noted in the zone of mid-oceanic ridges.

Tectonics of the oceans still includes such structures as deep-sea trenches, oceanic mountains and guillotas.

Causes of moving plates

The driving geological force is the tectonics of the world. The main reason for the motion of plates is mantle convection, which is created by the heat-gravitational currents in the mantle. This is due to the difference in temperature at the surface and at the center of the earth. Inside the rocks they heat up, their expansion and density decrease. Light fractions begin to float, and cold and heavy masses drop into their place. The process of heat transfer occurs continuously.

On the movement of plates are still a number of factors. For example, the asthenosphere in the zones of ascending currents is elevated, and in the immersed zones it is lowered. Thus, an inclined plane is formed and the process of "gravitational" sliding of the lithospheric plate takes place. Influence and subduction zones, where the cold and heavy oceanic crust is tightened under the hot continental.

The thickness of the asthenosphere under the continents is much smaller, and the viscosity is greater than under the oceans. Under the ancient parts of the continents, the asthenosphere is practically absent, so in these places they do not move and remain in place. And since the lithospheric plate includes both the continental and the oceanic part, the presence of the ancient continental part will impede the movement of the plate. The movement of purely oceanic plates is faster than mixed, and even more continental.

The mechanisms that drive the plates are many, conventionally they can be divided into two groups:

1. Mechanisms driving under the action of mantle flow.
2. Mechanisms associated with the application of forces to the edges of slabs.

The totality of the processes of motive forces reflects in general the geodynamic process that covers all layers of the Earth.

Architecture and Tectonics

Tectonics is not only purely geological science, connected with processes occurring in the bowels of the Earth. It is used in everyday life of a person. In particular, tectonics is used in the architecture and construction of any structures, be it buildings, bridges or underground structures. Here the basis of the laws of mechanics. In this case, tectonics refers to the degree of strength and stability of a structure in a given specific locality.

The theory of lithospheric plates does not explain the relationship between plate movements and deep processes. We need a theory that would explain not only the structure and motion of lithospheric plates, but also the processes taking place inside the Earth. The development of such a theory is connected with the unification of such specialists as geologists, geophysicists, geographers, physicists, mathematicians, chemists and many others.