Interesting facts about the lithosphere for children. Lesson plan "The structure of the lithosphere."
The lithosphere is the stone shell of the Earth. From the Greek "lithos" - a stone and "sphere" - a ball
The lithosphere is the outer solid shell of the Earth, which includes the entire earth's crust with part of the Earth's upper mantle and consists of sedimentary, igneous and metamorphic rocks. The lower boundary of the lithosphere is fuzzy and is determined by a sharp decrease in rock viscosity, a change in the propagation velocity of seismic waves, and an increase in the electrical conductivity of rocks. The thickness of the lithosphere on the continents and under the oceans varies and averages 25 - 200 and 5 - 100 km, respectively.
Consider in general terms the geological structure of the Earth. The third planet farthest from the Sun - the Earth has a radius of 6370 km, an average density of 5.5 g / cm3 and consists of three shells - bark, robes and i. The mantle and core are divided into inner and outer parts.
The Earth's crust is a thin upper shell of the Earth, which has a thickness of 40-80 km on the continents, 5-10 km under the oceans and makes up only about 1% of the Earth's mass. Eight elements - oxygen, silicon, hydrogen, aluminum, iron, magnesium, calcium, sodium - form 99.5% of the earth's crust.
According to scientific research, scientists were able to establish that the lithosphere consists of:
- Oxygen - 49%;
- Silicon - 26%;
- Aluminum - 7%;
- Iron - 5%;
- Calcium - 4%
- The composition of the lithosphere includes many minerals, the most common are feldspar and quartz.
On the continents, the crust is three-layered: sedimentary rocks cover granitic rocks, and granitic rocks lie on basalt ones. Under the oceans, the crust is "oceanic", two-layered; sedimentary rocks lie simply on basalts, there is no granite layer. There is also a transitional type of the earth's crust (island-arc zones on the outskirts of the oceans and some areas on the continents, such as the Black Sea).
The earth's crust is thickest in mountainous regions.(under the Himalayas - over 75 km), the middle one - in the areas of the platforms (under the West Siberian lowland - 35-40, within the boundaries of the Russian platform - 30-35), and the smallest - in the central regions of the oceans (5-7 km). The predominant part of the earth's surface is the plains of the continents and the ocean floor.
The continents are surrounded by a shelf - a shallow-water strip up to 200 g deep and an average width of about 80 km, which, after a sharp steep bend of the bottom, passes into the continental slope (the slope varies from 15-17 to 20-30 °). The slopes gradually level off and turn into abyssal plains (depths 3.7-6.0 km). The greatest depths (9-11 km) have oceanic trenches, the vast majority of which are located on the northern and western margins of the Pacific Ocean.
The main part of the lithosphere consists of igneous igneous rocks (95%), among which granites and granitoids predominate on the continents, and basalts in the oceans.
Blocks of the lithosphere - lithospheric plates - move along the relatively plastic asthenosphere. The section of geology on plate tectonics is devoted to the study and description of these movements.
To designate the outer shell of the lithosphere, the now obsolete term sial was used, which comes from the name of the main elements of rocks Si (lat. Silicium - silicon) and Al (lat. Aluminum - aluminum).
Lithospheric plates
It is worth noting that the largest tectonic plates are very clearly visible on the map and they are:
- Pacific- the largest plate of the planet, along the boundaries of which constant collisions of tectonic plates occur and faults form - this is the reason for its constant decrease;
- Eurasian- covers almost the entire territory of Eurasia (except Hindustan and the Arabian Peninsula) and contains the largest part of the continental crust;
- Indo-Australian- It includes the Australian continent and the Indian subcontinent. Due to constant collisions with the Eurasian plate, it is in the process of breaking;
- South American- consists of the South American mainland and part of the Atlantic Ocean;
- North American- consists of the North American continent, part of northeastern Siberia, the northwestern part of the Atlantic and half of the Arctic Oceans;
- African- consists of the African continent and the oceanic crust of the Atlantic and Indian oceans. It is interesting that the plates adjacent to it move in the opposite direction from it, therefore the largest fault of our planet is located here;
- Antarctic Plate- consists of the mainland Antarctica and the nearby oceanic crust. Due to the fact that the plate is surrounded by mid-ocean ridges, the rest of the continents are constantly moving away from it.
Movement of tectonic plates in the lithosphere
Lithospheric plates, connecting and separating, change their outlines all the time. This enables scientists to put forward the theory that about 200 million years ago the lithosphere had only Pangea - a single continent, which subsequently split into parts, which began to gradually move away from each other at a very low speed (an average of about seven centimeters per year ).
This is interesting! There is an assumption that due to the movement of the lithosphere, in 250 million years a new continent will form on our planet due to the union of moving continents.
When there is a collision of the oceanic and continental plates, the edge of the oceanic crust sinks under the continental one, while on the other side of the oceanic plate its boundary diverges from the plate adjacent to it. The boundary along which the movement of the lithospheres occurs is called the subduction zone, where the upper and plunging edges of the plate are distinguished. It is interesting that the plate, plunging into the mantle, begins to melt when the upper part of the earth's crust is squeezed, as a result of which mountains are formed, and if magma also breaks out, then volcanoes.
In places where tectonic plates come into contact with each other, there are zones of maximum volcanic and seismic activity: during the movement and collision of the lithosphere, the earth's crust collapses, and when they diverge, faults and depressions form (the lithosphere and the Earth's relief are connected to each other). This is the reason why the largest landforms of the Earth are located along the edges of the tectonic plates - mountain ranges with active volcanoes and deep-sea trenches.
Problems of the lithosphere
The intensive development of industry has led to the fact that man and the lithosphere have recently become extremely difficult to get along with each other: pollution of the lithosphere is acquiring catastrophic proportions. This happened due to the increase in industrial waste in combination with household waste and fertilizers and pesticides used in agriculture, which negatively affects the chemical composition of the soil and living organisms. Scientists have calculated that about one ton of garbage falls per person per year, including 50 kg of hardly decomposable waste.
Today, pollution of the lithosphere has become an urgent problem, since nature is not able to cope with it on its own: the self-purification of the earth's crust occurs very slowly, and therefore harmful substances gradually accumulate and eventually negatively affect the main culprit of the problem - man.
Lesson summary grade 5
Topic: Lithosphere - the "stone" shell of the Earth. The internal structure of the Earth. Earth's crust. The structure of the earth's crust.
The purpose of the lesson : to form an idea about the inner layers of the Earth and their distinctive features, about the movement of lithospheric plates.
Tasks:
To acquaint students with the inner layers: the earth's crust, mantle, core and their distinctive features. Define the term lithosphere.
Demonstrate the result of the movement of lithospheric plates.
To develop students' skills to analyze information, read a diagram, highlight the main thing, use additional information, work with a geographical map.
Teach students how to use e-textbooks.
Contribute to the formation of geographical thinking of schoolchildren, geographical culture.
During the classes:
Organizing time
Emotional mood.
Hello guys. I hope that our mutual work at the lesson will be fruitful, and that you are active. Sit down. Today we are starting a new topic. For successful work in the lesson, we have prepared everything you need: a textbook, a notebook, a simple pencil, a pen.
Knowledge update
Astronauts who have flown in outer space say that it has an excellent blue color when viewed from a spacecraft. Looks like a precious blue pearl.
This color is due to the properties of the atmosphere and the fact that the World Ocean covers 71% of its area.
What or who is it about?(About planet Earth)
Guys, I'll read the text to you now. You will carefully listen to the text, and then answer a series of questions.
“Initially, the planet was cold, then it began to warm up, and subsequently began to cool again. At the same time, the "light" elements were raised, and the "heavy" ones were lowered. This is how the original earth's crust was formed. Heavy elements formed the inner substance of the planet - the core and mantle.
What are these lines talking about? (On the hypothesis of the origin of the Earth. The Schmidt-Fesenkov hypothesis has fewer contradictions and answers more questions.)
From what cloud did our planet form?(From a cold gas and dust cloud.)
What is the shape of the earth?(The shape of the Earth is spherical.)
Remember from the material of natural history, what outer shells of the Earth do you know?(The earth has the following outer shells: atmosphere, hydrosphere, biosphere, lithosphere.)
Do shells interact with each other?(Yes)
Motivation of educational activity.
Once - a circle,
Two - a circle,
Three - a circle,
Circle again...
So many different skins!
Not the Earth, but just a bow!
The earth is cleverly designed
Harder than any toy
Inside is the CORE,
But not a cannonball!
Then, imagine, MANTIA
Lies inside the Earth.
But not such a mantle
What do kings wear?
Then - LITHOSPHERE
(Earth's crust).
We got to the surface
Hooray!
And in the middle of this LITO -
HYDROSPHERE spilled.
HYDRO is not HYDRA.
Still sometimes
People call her
WATER!
Well, beyond this area
We meet with the ATMOSPHERE.
(This is both air and clouds...)
What's behind her? - Unknown yet!
(A. Usachev)
Encryption task.
Decipher the topic of the lesson
S O R L A I F T E
Answer: LITHOSPHERE
Preparing students for learning a new topic.
Guys, do you like fairy tales? Now I want to tell you a story. Ready to listen?
In a certain kingdom, in a certain state, he lived - there was king Zakir. He had a son - a daring good fellow Ivan - Tsarevich. It became hard for King Zakir to rule, he grew old.
King Zakir decided to test his son. He sends him on a long journey, and he gives an order: “Go, Ivan - Tsarevich, to see the world and show yourself. Find me the key of the Earth, and then you will be the king.
Ivan Zakirov's son set off on his way - the road. How long did it go, how short, did it reach a foreign kingdom - a state. He sees: in front of him are 4 white palaces with golden roofs, and above them there is an inscription - “Atmosphere”, “Hydrosphere”, “Biosphere”, “Lithosphere”. Ivan read the inscriptions and wondered what it was.
Guys, let's tell Ivan what these words mean.
Ivan is standing at the gate, and the old man passes by and asks: “What, dear man, did you hang your head? »
“Yes, I need to find the key of the Earth, but I just can’t determine where I should go. Help me, good man.
The elder explained that Ivan needed to go to the palace called "Lithosphere".
“Is there a key of the Earth in this country?” asks the prince. “There is - that is, but it is not easy to find it. It is kept deep underground, and is guarded by a beautiful princess.”
“But how can I get there?” Ivan asks.
“We need to dig a deep well,” the old man answers him.
Ivan Zakirov's son took a shovel in his hands and began to dig a well. At first, it was easy for the prince to dig, the rocks came across light, loose: sand, clay, chalk, rock salt. Ivan digs deeper, the rocks become harder. He comes across iron ore - brown, magnetic, ores of useful metals.
Ivan the Tsarevich got carried away with his work, hit once, hit another, and a huge lump fell off. Ivan found himself in a large cave. Its walls shine, shimmer with precious stones. And in the center of the hall, a beautiful princess sits on a throne. Ivan bowed to her and said: “People say that you are hiding the key of the Earth, but I need it, I promised the priest to get it!”
“Well, if you guess my tasks, I’ll give you the cherished key!” the princess answered and handed Ivan an envelope with tasks.
"Guess, - said Ivan - Tsarevich, - I'll try to guess!".
What is the internal structure of the Earth?
The internal structure of the Earth is complex. At its center is the nucleus. Then follows the mantle, and the earth's crust. The structure of the Earth can be compared to an egg.
It consists of shell, protein and yolk. The shell is like the breathing earth's crust. She is very thin. Protein - mantle. The yolk is the core.
In diagram form, this can be represented as follows:
The internal structure of the Earth = core + mantle + earth's crust.
What is a core?
The core is divided into two layers: the inner core is solid, the outer is liquid. Composed of iron and nickel.
It used to be thought that the core of the Earth was smooth, almost like a cannonball.
It is assumed that the surface of the nucleus consists of a substance with the properties of a liquid. The boundary of the outer core is at a depth of 2900 km.
But the inner region, starting from a depth of 5100 km, behaves like a solid body. This is due to very high pressure. Even at the upper boundary of the core, the theoretically calculated pressure is about 1.3 million atmospheres. And in the center it reaches 3 million atmospheres. The temperature here can exceed 10,000 C°.
It is possible that the material of the outer core includes a relatively light element, most likely sulfur.
Core Composition = Iron + Nickel
What are the properties of the mantle?
Mantle translated from lat. language means "veil". It occupies up to 83% of the planet's volume and is divided into upper and lower mantle. The substance of the mantle is in a solid state due to the high pressure, although the temperature of the mantle is 2000 ° C. The middle layer of the mantle is slightly softened, while the inner and outer layers are in a solid state.
The first lies to a depth of 670 km. A rapid drop in pressure in the upper part of the mantle and a high temperature lead to the melting of matter.
At a depth of 400 km under the continents and 10 - 150 km under the oceans, that is, in the upper mantle, a layer was discovered where seismic waves propagate relatively slowly. This layer was called the asthenosphere (from the Greek "asthenes" weak). The asthenosphere, which is more plastic than the rest of the mantle, serves as a "lubricant" along which rigid lithospheric plates move.
What does it consist of? Mainly from rocks rich in magnesium and iron. The rocks of the mantle are characterized by high density.
What the lower mantle consists of remains a mystery.
What is the earth's crust?
The earth's crust is the hard upper shell of the earth. On the scale of the entire Earth, it represents the thinnest film and is negligible compared to the radius of the Earth. It reaches a maximum thickness of 75 km over the mountain ranges of the Pamirs, Tibet, the Himalayas. Despite the small power, the earth's crust has a complex structure.
Earth's crust
oceanic continental
5-10km 30-80km
The upper boundaries of the earth's crust are well studied by drilling wells (deep drilling method).
The deepest well has a depth of only 15 km. Compared to the size of the Earth, this value is very small. But, despite the fact that man penetrated deep into the Earth only a few kilometers, scientists obtained some information about its internal structure using geophysical methods. Geophysicists on the surface or at some depth below the surface produce explosions. Special, very sensitive instruments record the speed with which oscillations propagate inside the Earth. Thus, geophysicists have established that, down to an average depth of 30 km, the globe consists of sand, limestone, granite, and other rocks.
Temperature also changes with depth in the earth's crust. The temperature of the upper layer of the lithosphere varies with the seasons of the year. Below this layer, to a depth of about 1000 m, a pattern is observed: for every 100 m of depth, the temperature of the earth's crust increases by an average of 3 degrees.
How did the earth's crust form?
The formation of the earth's crust took place billions of years ago from the viscous-liquid substance of the mantle - magma. The most common and light chemicals included in its composition - silicon and aluminum - solidified in the upper layers. Having hardened, they no longer sank and remained afloat in the form of peculiar islands. But these islands were not stable, they were at the mercy of internal mantle currents that carried them down, and often simply drowned in hot magma. Magma (from the Greek tagma - thick mud) is a molten mass that forms in the Earth's mantle. But time passed, and the first small solid massifs gradually connected with each other, forming territories of a considerable area. Like ice floes in the open ocean, they moved around the planet at the behest of internal mantle currents.
How did people manage to get an idea of \u200b\u200bthe internal structure of the Earth?
Humanity receives valuable information about the structure of the Earth as a result of drilling ultra-deep wells, as well as using special seismic research methods (from the Greek "seismos" - oscillation). This is how geophysicists study our Earth. This method is based on the study of the propagation velocity in the Earth of oscillations that occur during earthquakes, volcanic eruptions or explosions. For this purpose, a special device is used - a seismograph. Seismologists obtain unique information about the bowels of the Earth from observations of volcanic eruptions. The science of seismology is the science of earthquakes. Based on seismic data, 3 main shells are distinguished in the structure of the Earth, differing in chemical composition, state of aggregation and physical properties.
Lithosphere
The stone shell of the Earth, including the earth's crust and the upper part of the mantle, is called the lithosphere. Under it is a heated plastic layer of the mantle. The lithosphere seems to float on this layer. The thickness of the lithosphere in different regions of the Earth varies from 20 to 200 kilometers or more. In general, it is thicker under the continents than under the oceans. Scientists have established that the lithosphere is not monolithic, but consists of lithospheric plates. They are separated from each other by deep faults. There are seven very large and several smaller lithospheric plates that constantly but slowly move along the plastic layer of the mantle. The average speed of their movement is about 5 centimeters per year. Some plates are entirely oceanic, but most have different types of crust.
Lithospheric plates move relative to each other in different directions: either move away, or, conversely, approach and collide. As part of the lithospheric plates, their upper "floor" - the earth's crust - also moves. Due to the movement of lithospheric plates, the location of continents and oceans on the surface of the Earth changes. The continents either collide with each other, or move away from each other for thousands of kilometers.
And now guys, let's get back to our fairy tale
“Well done, Ivan - Tsarevich, correctly guessed my tasks with the guys, here is the key of the Earth for you and remember: only knowledge, like a key, opens any locks and doors,” the princess told him.
Ivan bowed and went home, and so that he does not get lost, let's help him remember the way back.
Practical work
Complete the table using the textbook
| Earth's crust | Mantle | Core |
|
| Dimensions | 5 - 75 km | 2900 km | 3500 km |
| Components | mainland oceanic | upper mantle lower mantle | outer core inner core |
| State | hard | special (viscous) | external - liquid internal - solid |
| Temperature | small, with depth increases by 3 for every 100 m | high - 2000 C | very high - 2000 - 5000 C |
| Ways to study | surveillance, remote (from space), well drilling | geophysical seismology | |
Test tasks. Choose the correct answer.
1. The earth consists of:
a) Cores and mantles
b) The mantle and the earth's crust
V)Core, mantle and crust
d) the core and the earth's crust.
2. The core of the Earth consists of:
a) one layer
b)two layers
c) Three layers
Summarizing. Student assessment. Reflection.
Guys today in the lesson we set tasks: to study the internal structure of the Earth, study methods and the lithosphere.
How do you think we coped with these tasks?
So the goal of the lesson is achieved?
Each of you has emoticons printed on your desk that show your mood.
Note how you felt in class today.
The lesson is over. Thanks to all. Well done!
Earth is the 3rd planet from the Sun, located between Venus and Mars. It is the densest planet in the solar system, the largest of the four, and the only astronomical object known to contain life. According to radiometric dating and other research methods, our planet formed about 4.54 billion years ago. The Earth interacts gravitationally with other objects in space, especially the Sun and Moon.
The earth consists of four main spheres or shells, which are dependent on each other and are the biological and physical components of our planet. They are scientifically called biophysical elements, namely the hydrosphere ("hydro" for water), the biosphere ("bio" for living beings), the lithosphere ("litho" for land or the earth's surface), and the atmosphere ("atmo" for air). These main spheres of our planet are further divided into various sub-spheres.
Let us consider all four shells of the Earth in more detail in order to understand their functions and significance.
Lithosphere - the solid shell of the Earth
According to scientists, there are more than 1386 million km³ of water on our planet.
The oceans contain more than 97% of the water on Earth. The rest is fresh water, two-thirds of which is frozen in the planet's polar regions and on snowy mountain peaks. It is interesting to note that although water covers most of the planet's surface, it only makes up 0.023% of the Earth's total mass.
Biosphere - the living shell of the Earth
The biosphere is sometimes considered as one big - a complex community of living and non-living components, functioning as a whole. However, most often the biosphere is described as a collection of many ecological systems.
Atmosphere - the air shell of the Earth
The atmosphere is the collection of gases that surround our planet, held in place by the earth's gravity. Most of our atmosphere is near the earth's surface, where it is at its densest. Earth's air is 79% nitrogen and slightly less than 21% oxygen, as well as argon, carbon dioxide and other gases. Water vapor and dust are also part of the Earth's atmosphere. Other planets and the Moon have very different atmospheres, and some do not have one at all. There is no atmosphere in space.
The atmosphere is so widespread that it is almost invisible, but its weight is equal to a layer of water more than 10 meters deep, which covers our entire planet. The lower 30 kilometers of the atmosphere contain about 98% of its total mass.
Scientists claim that many of the gases in our atmosphere were ejected into the air by early volcanoes. At that time, there was little or no free oxygen around the Earth. Free oxygen is made up of oxygen molecules not bound to another element such as carbon (to form carbon dioxide) or hydrogen (to form water).
Free oxygen may have been added to the atmosphere by primitive organisms, probably bacteria, during . More complex forms later added more oxygen to the atmosphere. The oxygen in today's atmosphere probably took millions of years to build up.
The atmosphere acts like a giant filter, absorbing most of the ultraviolet radiation and letting the sun's rays through. Ultraviolet radiation is harmful to living beings and can cause burns. However, solar energy is essential for all life on Earth.
The Earth's atmosphere has The following layers go from the surface of the planet to the sky: troposphere, stratosphere, mesosphere, thermosphere and exosphere. Another layer, called the ionosphere, extends from the mesosphere to the exosphere. Outside the exosphere is space. The boundaries between atmospheric layers are not clearly defined and vary with latitude and seasons.
The relationship of the shells of the Earth
All four spheres can be present in one place. For example, a piece of soil will contain minerals from the lithosphere. In addition, there will be elements of the hydrosphere, which are moisture in the soil, the biosphere as insects and plants, and even the atmosphere in the form of soil air.
All spheres are interconnected and depend on each other, as a single organism. Changes in one area will lead to changes in another. Therefore, everything that we do on our planet affects other processes within it (even if we cannot see it with our own eyes).
For people dealing with problems, it is very important to understand the interconnection of all the shells of the Earth.
The lithosphere of the planet Earth is a solid shell of the globe, which includes multilayer blocks called lithospheric plates. As Wikipedia points out, in Greek it is "stone ball". It has a heterogeneous structure depending on the landscape and the plasticity of the rocks located in the upper layers of the soil.
The boundaries of the lithosphere and the location of its plates are not fully understood. Modern geology has only a limited amount of data on the internal structure of the globe. It is known that lithospheric blocks have boundaries with the hydrosphere and atmospheric space of the planet. They are in close relationship with each other and are in contact with each other. The structure itself consists of the following elements:
- Asthenosphere. A layer with reduced hardness, which is located in the upper part of the planet in relation to the atmosphere. In some places it has very low strength, is prone to fracture and viscosity, especially if groundwater flows inside the asthenosphere.
- Mantle. This is a part of the Earth called the geosphere, located between the asthenosphere and the inner core of the planet. It has a semi-liquid structure, and its boundaries begin at a depth of 70–90 km. It is characterized by high seismic velocities, and its movement directly affects the thickness of the lithosphere and the activity of its plates.
- Core. The center of the globe, which has a liquid etiology, and the preservation of the magnetic polarity of the planet and its rotation around its axis depends on the movement of its mineral components and the molecular structure of molten metals. The main component of the earth's core is an alloy of iron and nickel.
What is the lithosphere? In fact, this is a solid shell of the Earth, which acts as an intermediate layer between fertile soil, mineral deposits, ores and mantle. On the plain, the thickness of the lithosphere is 35–40 km.
Important! In mountainous areas, this figure can reach 70 km. In the area of such geological heights as the Himalayan or Caucasian mountains, the depth of this layer reaches 90 km.
Earth structure
Layers of the lithosphere
If we consider the structure of lithospheric plates in more detail, then they are classified into several layers, which form the geological features of a particular region of the Earth. They form the basic properties of the lithosphere. Based on this, the following layers of the hard shell of the globe are distinguished:
- Sedimentary. Covers most of the top layer of all earth blocks. It mainly consists of volcanic rocks, as well as the remains of organic matter, which have decomposed into humus over many millennia. Fertile soils are also part of the sedimentary layer.
- Granite. These are lithospheric plates that are in constant motion. They mainly consist of heavy-duty granite and gneiss. The last component is a metamorphic rock, the vast majority of which is filled with minerals from among potassium spar, quartz and plagioclase. The seismic activity of this layer of the hard shell is at the level of 6.4 km/sec.
- Basaltic. Mostly composed of basalt deposits. This part of the solid shell of the Earth was formed under the influence of volcanic activity in ancient times, when the formation of the planet took place and the first conditions for the development of life arose.
What is the lithosphere and its multilayer structure? Based on the foregoing, we can conclude that this is a solid part of the globe, which has a heterogeneous composition. Its formation took place over several millennia, and its qualitative composition depends on what metaphysical and geological processes took place in a particular region of the planet. The influence of these factors is reflected in the thickness of the lithospheric plates, their seismic activity in relation to the structure of the Earth.
Layers of the lithosphere
oceanic lithosphere
This type of the earth's shell is significantly different from its mainland. This is due to the fact that the boundaries of the lithospheric blocks and the hydrosphere are closely intertwined, and in some of its parts the water space extends beyond the surface layer of the lithospheric plates. This applies to bottom faults, depressions, cavernous formations of various etiologies.
oceanic crust
That is why oceanic-type plates have their own structure and consist of the following layers:
- marine sediments that have a total thickness of at least 1 km (may be completely absent in deep ocean areas);
- secondary layer (responsible for the propagation of medium and longitudinal waves moving at speeds up to 6 km / s, takes an active part in the movement of plates, which provokes earthquakes of various power);
- the lower layer of the solid shell of the globe in the region of the ocean floor, which is mainly composed of gabbro and borders on the mantle (the average activity of seismic waves is from 6 to 7 km/sec.).
A transitional type of lithosphere is also distinguished, located in the region of oceanic soil. It is characteristic of insular zones formed in an arcuate manner. In most cases, their appearance is associated with the geological process of the movement of lithospheric plates, which were layered on top of each other, forming such irregularities.
Important! A similar structure of the lithosphere can be found on the outskirts of the Pacific Ocean, as well as in some parts of the Black Sea.
Useful video: lithospheric plates and modern relief
Chemical composition
In terms of filling with organic and mineral compounds, the lithosphere does not differ in diversity and is mainly represented in the form of 8 elements.
For the most part, these are rocks that were formed during the period of active eruption of volcanic magma and the movement of plates. The chemical composition of the lithosphere is as follows:
- Oxygen. It occupies at least 50% of the entire structure of the hard shell, filling its faults, depressions and cavities that form during the movement of plates. Plays a key role in the balance of compression pressure during the course of geological processes.
- Magnesium. This is 2.35% of the solid shell of the Earth. Its appearance in the lithosphere is associated with magmatic activity in the early periods of the formation of the planet. It is found throughout the continental, marine and oceanic parts of the planet.
- Iron. Rock, which is the main mineral of lithospheric plates (4.20%). Its main concentration is the mountainous regions of the globe. It is in this part of the planet that the highest density of this chemical element is. It is not presented in a pure form, but is found in the composition of lithospheric plates in a mixed form, along with other mineral deposits.
- Bark (earthly);
- Mantle;
- Core.
- When sand or clay collapses;
- During the course of chemical reactions in water;
- Organic rocks arose from chalk, peat, coal;
- Due to changes in the composition of rocks - in whole or in part.
- Resource;
- Geodynamic;
- Geochemical;
- Geophysical.
- The lithosphere arose in the process of gradually liberating substances from the Earth's mantle. Similar phenomena are still sometimes observed at the bottom of the ocean, as a result of which gases and a little water appear.
- The thickness of the lithosphere varies depending on the climate and natural conditions. So, in cold regions, it reaches its maximum value, and in warm regions it remains at minimum levels. The uppermost layer of the lithosphere is elastic, while the lower one is very plastic. The solid shell of the Earth is constantly under the influence of water and air, which causes weathering. It is physical when the rock breaks up, but its composition does not change; as well as chemical - new substances appear.
- Due to the fact that the lithosphere is constantly moving, the appearance of the planet, its relief, the structure of plains, mountains, and low mountains are changing. Man constantly influences the lithosphere, and this participation is not always useful, as a result of which serious pollution of the shell occurs. First of all, this is due to the accumulation of garbage, the use of poisons and fertilizers, which changes the composition of soils, soil, and living beings.
The lithosphere is the solid shell of the Earth.
Introduction
The lithosphere is important for all living organisms that live on its territory.
First of all, people, animals, insects, birds, etc. live on land or inside it.
Secondly, this shell of the earth's surface has huge resources that organisms need for food and life.
Thirdly, it contributes to the functioning of all systems, the mobility of the bark, rocks and soil.
What is the lithosphere
The term lithosphere consists of two words - a stone and a ball or sphere, which literally translated from Greek means a hard shell of the earth's surface.
The lithosphere is not static, but is in constant motion, which is why plates, rocks, resources, minerals, and water provide organisms with everything they need.
Where is the lithosphere
The lithosphere is located on the very surface of the planet, goes inside the mantle, to the so-called asthenosphere - the plastic layer of the Earth, consisting of viscous rocks.
What is the lithosphere made of?
The lithosphere has three interrelated elements, which include:
structure of the lithosphere photo
In turn, the crust and the uppermost part of the mantle - the asthenosphere are solid, and the core consists of two parts - solid and liquid. Inside the core has solid rocks, and outside it is surrounded by liquid substances. The composition of the crust includes rocks that arose after cooling and crystallization of magma.
Sedimentary rocks arise in various ways:
Scientists have established that the lithosphere consists of such important elements as oxygen, silicon, aluminum, iron, calcium, and minerals. According to its structure, the lithosphere is divided into mobile and stable, i.e. platforms and folded belts.
A platform is commonly understood as areas of the earth's crust that do not move, as a result of the presence of a crystalline base. It is either granite or basalt. In the middle of the continents, ancient platforms are usually located, and at the edges - those that arose later, in the so-called Precambrian period.
Folded belts arose after they collided with each other. As a result of such processes, mountains and mountain ranges arise. Most often they are located at the edges of the lithosphere. The most ancient can be seen in the center of the mainland - this is Eurasia, or along the very edges, which is typical for America (Northern) and Australia.
Mountains are constantly forming. If a mountain range passes through a tectonic plate, then this means that once there was a collision of plates here. In the lithosphere, 14 plates are distinguished, which is 90% of the entire shell. There are both large and small plates.
tectonic plates photo
The largest tectonic plates are the Pacific, Eurasian, African, and Antarctic. The lithosphere under oceans and continents is different. In particular, under the former, the shell consists of oceanic crust, where there is almost no granite. In the second case, the lithosphere consists of sedimentary rocks, basalt and granite.
The boundaries of the lithosphere
Features of the lithosphere has different outlines. The lower boundaries are blurred, which is associated with a viscous medium, high heat conductivity and seismic wave velocity. The upper boundary is the crust and mantle, which is thick enough to change only due to the plasticity of the rock.
Functions of the lithosphere
The solid shell of the earth's surface has geological and ecological functions, which determine the course of life on the planet. Underground waters, oil, gases, fields of geophysical significance, processes, participation of various communities take part in it.
Among the most important functions are:
Functions are manifested under the influence of natural and man-made factors, which is associated with the development of the planet, human activities and the formation of various ecological systems.
