Why do mountains age? Interesting facts about mountains
Structure of the Earth. (10-12 min)
1. -Let's check the versions of the formation of the Earth.
Everyone knows that the Earth is a ball. The secret of mountain formation must be sought within the Earth.
The internal structure of the Earth resembles a chicken egg (show).
The core is the yolk.
The mantle is white.
Bark is a shell.
The teacher suggests creating a model of the Earth from plasticine, and during the work he comments, naming the main layers.
Core - represents red-hot molten metals at t=5000 °C.
The mantle (in fairy tales the cape of kings) is a molten mass, constantly flowing; heating up from the core, it rises, then falls down. It's like stone porridge is being cooked.
The earth's crust is a thin upper hard layer (comparable in thickness to a postage stamp stuck on a ball). The actual thickness is 100 km. (Cut the Earth model, repeat layers).
Whose picture is more correct?
2. Formation of mountains (2-3 min).
The crust consists of individual plates that float like ice floes during ice drift, only very slowly, at a speed of 1-2 cm per year. Let us depict the movement of plates, for example, Euro-Asian and Indo-European.
An outdoor game “Plate Movement”, during which the reasons for the formation of mountains are revealed.
3.
Earthquake, volcanic eruption (2-3 min).
As a result of the movement of plates, mountains are formed. But all movements are accompanied by earthquakes, volcanic eruptions and other disasters. The spectacle is stunning in beauty, but incredibly terrible in its destructive powers.
How fast is the lava speed of a volcano? Outdoor game “Escape from the volcano” (according to the principle of running a race).
It is unlikely that you will be able to escape from a volcano, because average speed the flow of lava was 50 km/h, and during the eruption of Mount Vesuvius in Pompeii, the lava flowed at a speed of 150 km/h.
The largest cataclysms in human history.
-
What major and destructive earthquakes of our time do you know about?
On March 11, 2011, a strong earthquake occurred in Japan. The resulting tsunami wave, several tens of meters high, partially destroyed the Fukushima-1 nuclear plant and damaged the cooling system. The accident caused radioactive contamination of the area and the discharge of radioactive water into Pacific Ocean. The earthquake claimed the lives of almost 16 thousand people.
And in 79 AD. The eruption of Mount Vesuvius wiped out several cities from the face of the Earth, including the flourishing city of Pompeii.
Working with textbook illustrations (p. 119)
What's happening in the picture?
What mood does it evoke?
What surprised you?
And only in the 19th century the city was accidentally discovered and after excavations, it appears practically unharmed before our contemporaries.
4. Mountains: old and young (5-7 min.)
Mountains are a symbol of inviolability and eternity. But the mountains are also aging and being destroyed.
Which picture shows old mountains and which shows young ones?
By what signs did you guess?
Why do mountains age and collapse? Find the answer to this question in the textbook on p. 117.
How do water, wind, plants destroy mountains?
Therefore, younger mountains are steep, with sharp peaks, while older ones are smooth, with gentle slopes.
Have we achieved any goal of the lesson? What goal remains to be achieved?
Mountains are not eternal, they are “born” and “age”, gradually turning into hills. But how are mountains formed, how do these majestic accumulations of stone giants appear?
As scientists have found out, mountains are formed, or were formed millions of years ago, in four different ways and, according to the method of formation, are folded, vaulted, solid or volcanic.
How fold mountains form
Fold mountains were formed as a result of pressure and compression earth's surface during tectonic movement of the earth's crust. They look like giant folds of rock layers. Example fold mountains are the Alps.
How vaulted mountains are formed
Vaulted mountains are rocks that were raised above the surface of the Earth by molten lava as it moved outward from the bowels of the earth. Such mountains are characterized by the shape of the arch, which is why they are called that.
How are solid mountains formed?
Whole mountains were formed when entire sections of the earth's surface rose or fell during tectonic movement. Whole mountain ranges(for example, Sierra Nevada) is the result of faults or, conversely, failures in the earth’s crust.
How are volcanic mountains formed?
Volcanic mountains are extinct or (for example, Vesuvius or Fuji). They consist of lava emitted during volcanic eruptions of ash and have a conical shape.
These are the main ways mountains are formed, but many mountains are the result of their combination during tectonic movement of layers of the earth's crust.
Mount Kailash (Kangrinboche) is surrounded by many myths and all due to the fact that no human has yet set foot on it; the peak remains unconquered even in the 21st century. Mount Kailash has great religious significance in Hinduism, Buddhism, Jainism, Tibetan Bon tradition.
So, for a long time on the site there was an article written by the author, “Marisa263”, in the comments you can see the indignation of visitors pointing out many inaccuracies and frankly fictitious facts. I decided that simply rewriting the article was not very interesting; it was better to go through each point and refute or confirm them. Under each point, I added the facts I found and my thoughts on this matter.
1 Mount Kailash and its height
Statement No. 1. “Mount Kailash is one of the mysterious places height in the world, which is 6666 meters.”
Wikipedia gives a different figure of 6638 meters with a link to Peakbagger.com. It is also said that scientists disagree between 6638 and 6890 meters, depending on the method of measurement.
2 On the opposite side of the Earth is the skeleton of Easter
Statement No. 2. On the opposite side of the Earth from Mount Kailash is the Easter Island, which is famous for its stone idols.
Probably everyone remembers from the geometry course that two points on a sphere can be connected by a segment; this segment is called a chord. So the chord connecting Easter Island and Mount Kailash really runs close to the center of the Earth,
It’s difficult to say exactly through the center, but it can be argued that the Easter skeleton is on the opposite side of the Earth.
3 People age faster near Kailash
Statement No. 3. that near Kailash people age faster (12 hours passes in approximately 2 weeks), this is evidenced by the growth of hair and nails.
In fact, it is a fact known to science that the growth of nails and hair slows down in the cold, which probably explains the observation.
4 Mount Kailash remains unconquered
Statement No. 4. She has not yet allowed a single climber to reach her peak, those who tried to “throw off” the mountain. The religious texts of Buddhism and Hinduism say the following about Kailasa: “No mortal dares to climb the mountain where the gods live; he who sees the faces of the gods must die.”
In fact, in 2000, a Spanish expedition received permission to conquer Kailash from the Chinese authorities. The team set up a base camp at the foot, but they were never able to set foot on the mountain. Thousands of pilgrims blocked the expedition's path. The Dalai Lama, the UN, a number of major international organizations, millions of believers around the world protested the conquest of Kailash, and the Spaniards had to retreat
Statement No. 5. Near the mountain there are two lakes: Manasarovar (living and clean water) and Rakshas Tal (in Tibetan, Lhanag Tso, "Lake of the Demon"). In Lake Manasarovar (fresh), which is located at an altitude of 4560 m above sea level, you can swim, drink water, it is considered sacred, and it is calm at any time of the year in any weather.
Rakshasa (), 4515m above sea level. Counts dead lake water that you can’t not only drink, but also touch, and there is a storm on this lake at any time of the year and in any weather.
Perhaps, according to beliefs local population this is true, but on the Internet there are photos of tourists not only touching, but also swimming in Lake Rakshas Tal.
6 Kailash and the image of the swastika
Statement No. 6. Mount Kailash is broken by two huge ridges - cracks, which, especially in the evening hours, with the help of the shadows from the rock ledges, form a huge image of a swastika.
I added a photo in the evening hours, I added a photo where there is less snow, what can I say, the slope is riddled with cracks, the cross is visible, well, there is no swastika, but if you want, you can probably find a swastika in the abundance of cracks.
7 Kailash is a pyramid
Statement No. 7. The fact that Mount Kailash is a pyramid (which, like other pyramids, is clearly oriented to the cardinal points) is no longer an innovation. All scientists who have visited Kailash have no doubt about its pyramidal nature.
I am attaching a screenshot from google maps, with a compass needle and axes marked, everything is obvious here. Like the Pyramid of the Sun in Bosnia, the mountain is a natural geological formation known as a flatiron.
8 Mount Kailash - an artificial formation
Statement No. 8. Many scientists consider this mountain to be an artificial formation, with some voids inside (at the level of the middle and at the foot), which was built by someone, for something and with a specific purpose.
This is as difficult to prove as it is difficult to refute without special research, so I will express my opinion - this is a mountain, a natural formation.
9 From Mount Kailash to the Stonehenge monument (England) – 6666 km.
Statement No. 9. From Mount Kailash to the Stonehenge monument (England) – 6666 km. To the North Pole – 6666 km. From the mountain to the south pole two times 6666 km.
The photo speaks for itself.
10 Sarcophagus of Nandu
Statement No. 10. Sarcophagus of Nandu, a structure adjacent to Mount Kailash. After some research, scientists have proven that this sarcophagus also has cavities inside. Where, according to the ancient legends of China, all the teachers of the world are in a state of samadhi (deep meditation): Jesus, Buddha, Krishna, Zarathustra, Confucius and other sages that were ever sent to the world. And they stay there in order to serve as a continuation of the gene pool of humanity in the event of the collapse of civilization.
The research data are not given, which means it is impossible to verify them, just like point 8.
Goals and objectives.
Educational:
- introduce the characteristic features and nature of mountains, explain the reasons for their occurrence;
- teach how to find mountains on maps.
Educational:
- develop skills in working with maps and reference literature;
- develop skills and abilities of independent and group work.
Educators:
- contribute to the enrichment and development of students’ subjective ideas about nature.
Basic knowledge, abilities, skills.
- globe, map, symbols for them;
- parts of the world, continents;
- characteristics mountains, plains;
- main natural areas;
- about the change natural areas on the surface of the Earth.
- use laws and rules to make sense of their experiences;
- use the book to answer questions;
- learn to read and use a map;
- master basic map reading techniques (identifying land and water, altitude, landforms, symbols);
- show continents on the map;
- identify plains and mountains on the map;
- show main geographical features on a physical map in different parts of the world.
Equipment.
For students:
- textbook-notebook “Our planet Earth”, part 1;
- individual worksheets;
- textbook on geography “Our world. Mountains".
For the teacher:
- textbook – notebook “Our Planet Earth”, part 1;
- textbook on geography “Our world. Mountains";
- physical map of the hemispheres;
- tables “Plains”, “Mountains”;
- reproductions of paintings by M.Yu. Lermontov to his works about mountains.
During the classes
Teacher's activities. UUD ( in the table)
I. Organizational moment
Hello guys.
II. Updating basic knowledge. Motivation
What did we study in the last lesson? (The nature of the Earth, its surface)
What shape of the Earth's surface are you already familiar with? (Plains)
What can you tell us about the plains? (When answering, use the “Plains” table)
Do you think there are other surface shapes?
Justify your opinion.
“I saw piles of dark rocks,
When the stream separated them...
I have seen mountain ranges,
Bizarre, like dreams...
In the distance I saw through the fog
In the snow, burning like a diamond,
The gray, unshakable Caucasus.”
M.Yu. Lermontov
(Demonstration of reproductions of sketches by M.Yu. Lermontov)
What the great Russian poet M.Yu. wrote so enthusiastically about. Lermontov? (About the mountains)
But he also made illustrations for his works.
(Demonstration of reproductions)
What struck him and led him to such admiration?
What will we talk about in class today?
What can we call our lesson?
I propose to take a line from V. Vysotsky’s song “Only mountains can be better than mountains...”
(Write the topic on the board)
III. Formulation of the problem. Goal setting
What would you like to learn about in class today?
What questions would you like answered on this topic?
IV. Discovery of new knowledge
What are they called mountains?
What shape do mountains have?
How are mountains formed?
What do you think about it?
(Working with illustrations, explanatory dictionary)
Were the proposals confirmed?
Prove using the textbook text.
Conclusion.
Mountains are elevations on the earth’s surface, most often associated with the activity of the underground forces of the Earth.
What forces take part in creating the appearance of the planet?
What is weathering called?
Weathering is the destructive activity of water, wind and other natural forces.
Summarize your knowledge.
Let's make a diagram:
Look carefully at the “Mountains” table.
What conclusion can be drawn?
In what form can it be written?
Why are they called that?
How do mountains “age”? Try to explain.
- pp. 12-13 – volcanoes;
- pp. 14-15 - plate collision;
- pp. 18-19 – erosion.
Using the knowledge you have gained, find young and old mountains in the pictures. Justify your choice.
(Compare the Caucasus and Ural mountains)
Physical education minute
First I will be a plain,
I'll press myself to my knees.
Then I will turn into a mountain,
I can immediately reach the sky.
(Squat down, hug your knees with your hands. Stand on your toes, stretch your arms up)
V. Inclusion in the knowledge system
Workshop on independent application and use of acquired knowledge.
Read the assignment on the sheets carefully:
Using “ Physical card hemispheres” connect the names of the rivers with the names of the mountains in which their sources are located .
What knowledge do you think is necessary to complete this task? Do we have all the knowledge necessary to complete the task?
Show each geographic pair on a map.
(Work with a map at the board. Check using a sample)
m. South America-> Andes city -> r. Amazon
m. North America -> Cordillera city -> r. Missouri
Europe -> Alps -> r. Danube
m. Eurasia
Asia -> Himalayas -> r. Ganges
Physical education minute: eye exercises “Butterfly”, “Owl”.
Inclusion in the knowledge system and repetition.
Think about what the nature of the mountains will be like?
Explain how you understand what altitudinal zonation is.
Let's check ourselves. Find the definition in a dictionary.
Altitudinal zones are ecosystems that replace each other as you climb the mountains.
Why does nature change the higher we climb into the mountains?
Working with the textbook on geography “Our World. Mountains”, Volgograd cooperative “Book”. 1995
Page 22 – weather and climate in the mountains depend on altitude,
Page 24 – 25 – flora (using the example of the vegetation of the Himalayas),
Page 26 - 27 – fauna (using the example of the animal world of the Himalayas).
VI. Homework
Optionally.
Plants and animals of the mountains. (Drawings, applique, etc.)
- “People and Mountains”
Think about whether people can live in the mountains. What will they be able to do?
Do mountains need protection? Prove your assumptions.
If so, what can you suggest to protect them?
VII. Lesson summary. Reflection
What goals did you set for yourself at the beginning of the lesson?
How did you obtain knowledge?
What new did you learn?
(Mountains are characterized by a number of properties: elevated surface, pointed shape, etc. Mountains arise as a result of the action of underground forces and are destroyed by weathering. Volcanic eruptions and earthquakes can occur in the mountains)
What was interesting about the lesson?
What was the main thing in the lesson?
What succeeded? What else needs work?
What else would you like to know?
The nature of the Earth is majestic and unique. Mysterious depths of the seas and oceans. The submissive muttering of lowland rivers and the indignant roar of mountain rivers. Endless plains beckoning into the distance. Mighty, awe-inspiring mountains... All this is powerful, but at the same time fragile, and therefore requires care and careful treatment.
Thank you for your work in class and for your activity.
Goodbye! Wish you luck!
Literature
- Educational system “School 2100”.
- Common sense pedagogy. Collection of materials / Scientifically edited by A.A. Leontyev. - M.: “Ballas”, RAO Publishing House, 2003.
- Educational system “School 2100”. Our planet Earth. 2nd grade. Methodological recommendations for teachers on the course of the surrounding world “The World and Man”. A.A. Vakhrushev, O.V. Bursky, A.S. Rautian. – M.: “Balass”, 2002.. Textbook-notebook for 2nd grade “Our Planet Earth”. In 4 parts. Part 2. / Team of authors under the leadership of A.A.
- Vakhrusheva. – M.: “Balass”, 2004
- Educational system “School 2100”.
The world. Textbook-notebook for 2nd grade “Our Planet Earth”. In 4 parts. Part 4. / Team of authors under the leadership of A.A.
Vakhrusheva. – M.: “Balass”, 2004 Mountains. Geography textbook for schoolchildren: Translation from English, revised and expanded. / Edited by T. Ronina. – Volgograd: cooperative “Book”, “International Center for Education Weiland - Volgograd”, 1995..
First, let's look at what is currently known about the structure and development of mountain systems. Mountains have some special features. The first of them is the stages of development. There are usually three stages. First -.
period of subsidence and accumulation of thick sedimentary strata Second - stage of formation and formation of mountains
And finally, the third - stage of aging and destruction of mountains. This sequence of the mountain building process was noticed during the formation of the doctrine of geosynclines (late 19th - early 20th centuries). However, in our opinion, the doctrine of the development of mountains misses a very significant, although outwardly inconspicuous, stage, which can be conventionally called prageosynclinal
, i.e., preceding the emergence of a geosynclinal depression. It was discovered only now, at the stage of widespread use of deep drilling and seismic methods, which made it possible to better understand the structure of mountains and foothills. The presence of this stage is confirmed, for example, by analysis
The structural diversity is often so great that it seems as if neighboring areas are not parts of a single mountain structure.
Finally, the third feature of mountains is that within their boundaries the earth’s crust is thickened. With an average thickness of 30-35 km on the continents, in young folded systems - the Pamirs, Caucasus, Alps, Cordillera, Hades - it reaches 50-62 km. And since the mountains do not rise above 7-8 km above sea level, the crust within them is, as it were, pressed into the peridotite shell, forming “mountain roots.”
According to geophysicist I.P. Kosmiiskaya, thickening of the crust in young mountain ranges occurs due to a thicker granite layer.
In fact, in terms of the speed of propagation of seismic waves, this part is quite close to granites. But are they granites?
As already mentioned, the thickness of folded sedimentary strata in mountainous areas reaches twenty or more kilometers, in any case, it is almost always at least fifteen. This is probably exactly the value that corresponds to the thickness of the granite part of the crust that is missing here, and sedimentary rocks in mountainous areas apparently lie directly on basalts. This is confirmed by geophysical data on typical geosynclinal depressions - the Black Sea and Caspian.
Do all mountains have roots? No, this belongs only to young folded systems, therefore, at the stage of subsidence and during the era of aging mountains, there are no roots. Consequently, only when mountains rise upward and their bases sink down into the peridotite zone do mountain roots appear.
These are the facts. They require an explanation.
Let's see, in terms of the named stages of development of mountain systems, how these facts are linked with the idea of the expansion of the Earth. The first stage is prageosynclinal. It is characterized by the accumulation, sometimes quite significant, of sedimentary strata lying horizontally, and a complete absence of volcanism. Consequently, there is still no direct connection with the deep strata of the Earth. The accumulation of sediments is obviously due to the stretching (but not rupture) and subsidence of the granite layer of the earth's crust.
The second stage, actually geosynclinal, is a time of long-term subsidence and accumulation of thick sedimentary strata, accompanied by intense outpourings of lavas and active volcanic activity. The stage under consideration is caused by further stretching and rupture of the granite part of the crust, which leads to direct contact of sedimentary rocks with deep crystalline rocks. From the basalt strata, now covered by crushed rocks of the granite layer and relatively loose sedimentary rocks, magma is easily released, literally filled with expanded (due to a decrease in pressure) gases.
The third stage - the stage of formation of folds and mountains - can also be explained by accepting the expansion hypothesis, although it would seem that this is where its Achilles heel is located. After all, it is usually believed that folds are the result of lateral pressure or pressure coming from below. And suddenly - denial of both.
Why, in our opinion, cannot be considered lateral pressure as the main factor leading to the formation of folds? Because it cannot be transmitted over a distance of many hundreds of kilometers, and will be extinguished already a few kilometers from the pressing object.
In addition, the juxtaposition of different areas found in some mountainous areas can serve as confirmation that there were probably no single mountain-building movements that formed the entire mountain system at once, and each area arose on its own, individually.
Then, perhaps, the mechanism of “vertically moving pistons” was at work here? It’s unlikely, since simultaneously with the rise of the mountain peaks to sky-high heights, their roots were embedded downwards, i.e., the movement simultaneously went in opposite directions.
So, we can assume that neither horizontal compression nor vertical uplift could lead to the formation of mountains. Therefore, one thing remains: the mountains are probably formed as a result of the decompression of crystalline and sedimentary rocks that make up the upper part of the earth’s crust.
Is it not surprising that we now have to return to the conclusion made back in 1899 by Dutton, who indicated that one of the reasons for mountain building is “... the gradual expansion or decrease in the density of underground magmas.”
To the idea of “swelling”, how possible reason formation of mountains, I.V. Kirillov also came. His idea formed the basis of our development.
Under what conditions and how does the “swelling process” occur, from our point of view? It must proceed especially energetically at the base of mountains, since magmas saturated with expanded gases “act” there. But “swelling” alone is not enough for mountains to arise, since the rocks “swell” first under conditions of stretching of the crust and, therefore, cannot rise upward, constantly spreading to the sides. And only at moments when extension stops, when the increased volume of rocks no longer have access to the sides, they rise up with force and are pressed down into the plastic basalt mass, forming mountains and their roots.
Since the history of the Earth is dominated by extension, and its temporary pauses are not very long, the eras of mountain building turn out to be much shorter than the preceding periods of the formation of geosynclinal troughs. It is not without reason that the eras of mountain building are called revolutionary stages in the development of the Earth, during which its face is dramatically transformed.
Finally, the last stage is the stage of mountain aging. This process is also explained from the perspective of the expansion hypothesis.
Aging is a slowdown of some active processes, due to which destruction begins to prevail over creation. This is what happens in this case. We have seen that the introduction of magmas saturated with expanded gases is a consequence of an imbalance, and as soon as it is restored - and this happens at a time when magmas are degassed and sedimentary rocks are granitized - the very process of growth of mountains and their roots dies out and begins destruction occurring under the influence of water, weathering and other factors.
The tops of the mountains disappear, and their roots are pulled up. After several stages of folding, geosynclinal zones turn into young platform areas.
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