What lithospheric plates lie at the base of Eurasia. Within what lithospheric plates is the territory of Russia located? Lithospheric plates of Russia

In my understanding, the lithospheric plate was something like a piece of a leaf floating on the water surface of a puddle. In fact, these substances are of colossal dimensions, and their movement even by a few millimeters entails tsunamis, earthquakes, eruptions...

What is a lithospheric plate

Scientists call the lithospheric plate stable and solid area earth's surface, both oceanic and continental. In essence, these are huge pieces of magma that came to the surface of the Earth several billion years ago and solidified in the process of cooling. They "drift" just on the same magma until now. At the borders where they collide, natural disasters occur that take a large number of lives, the ecosystem is destroyed, the climate changes. With the movement of lithospheric plates, the emergence of continents is associated even before the appearance of life on Earth.

The structure of the lithospheric plate

Considering the issue of the origin of lithospheric plates, it will not be superfluous to focus on their structure. This is necessary in order to understand how they differ from their constituent parts.

So here it is the lithospheric plate is from more stable formations - platforms. As a rule, the platform is called the flat part of the plate. At the foot of each platform is crystal shield.

Crystal shield- this is the base of the platform, a characteristic feature of which are relatively shallow deposits of minerals from the earth's surface.

Lithospheric plates of Russia

Russia occupies its territory only two continental lithospheric plates:

Eurasian lithospheric plate includes the following stable formations of the earth's crust:

1. Scythian platformsa- the smallest territory of Russia is located on it. These are Rostov and Volgograd regions, Stavropol and Krasnodar regions.

2. East European platform- european part of Russia.

3. West Siberian platform- located between the Ural Mountains and Lake Baikal.

4. Siberian platform- located within the territory from Lake Baikal to the hills of Kamchatka.

5. Anabar, Aldan (Amur Plate), and Baltic crystalline shields.

The volcanoes of Kamchatka are part of North American Plate. The mountain ranges of Kamchatka are the place where two lithospheric plates collide, on which the territory of Russia is located - the North American and Eurasian lithospheric plates.

East of Sakhalin is another plate - the Pacific. I think its belonging to the territorial waters of Russia is doubtful.

Unlike other continents, which are large fragments of the fragmented foremothers of Gondwana and Laurasia, Eurasia was formed as a result of the union of ancient lithospheric blocks. Approaching under the influence of internal processes, at different geological times, these blocks were connected by "seams" of folded belts, gradually "composing" the mainland in its modern configuration and size (see figures).

And you know that... At an early stage of geological history, having “folded” the pro-continent of Laurasia, the fragments of Pangea united - the ancient North American, East European, Siberian and Chinese platforms. In the zone of their convergence, ancient folded belts were formed - the Atlantic and the Ural-Mongolian. Then North America was "torn off" from Laurasia; at the site of the rift split, the basin of the Atlantic Ocean “opened up”. Drifting to the west, the North American plate "circled" the planet and rejoined Eurasia - already in the east. Folded systems appeared in the connection zone Northeast Siberia. Later, another fragment of Gondwana, the Indo-Australian lithospheric plate, moved from the southeast to Eurasia, and the Himalayan fold belt was laid in the zone of their convergence. At the same time, the Pacific fold belt began to form along the eastern margin of Eurasia in the zone of its contact with the Pacific lithospheric plate. The development of both fold belts continues to the present geological time. The entire southern margin of the Eurasian plate is outlined by the Alpine-Himalayan belt, which is formed under the pressure of the fragments of Gondwana - Hindustan, Arabia and Africa. And on the eastern outskirts of the mainland, chains of volcanic island arcs of the Pacific belt are “moving” to its edge, “growing” the massif of Eurasia.

The modern continent of Eurasia is located in the junction zone of five large lithospheric plates. Four of them are continental, one is oceanic. Most of Eurasia belongs to the continental Eurasian plate. The southern peninsulas of Asia belong to two different continental plates: the Arabian (Arabian Peninsula) and the Indo-Australian (Indostan Peninsula). The northeastern margin of Eurasia is part of the fourth continental plate - the North American. And the eastern part of the mainland with adjacent islands is the zone of interaction between Eurasia and the oceanic Pacific plate. Folded belts are being formed in the junction zones of lithospheric plates. On the southern edge of the Eurasian plate - the Alpine-Himalayan belt: it contains the southern outskirts of Europe, the Crimean Peninsula and Asia Minor, the Caucasus, the Armenian and Iranian highlands, the Himalayas. On the eastern edge of the mainland - the Pacific belt, in which the Kamchatka Peninsula, the Sakhalin Islands, the Kuril Islands, the Japanese, and the Malay Archipelago are located.

V composition of the Eurasian continent, includes five ancient platforms; all of them are "fragments" of the ancient foremother Pangea. Three platforms - East European, Siberian and Chinese - after the split of Pangea made up the ancient northern continent of Laurasia. Two - Arabian and Indian - were part of the ancient southern continent of Gondwana. The platforms are "connected" to each other by folded belts that formed at different geological times.

Everything ancient platforms of Eurasia have a two-tiered structure: the rocks of the sedimentary cover lie on the crystalline basement. The foundations are composed of igneous and metamorphic rocks, the sedimentary cover is composed of marine and continental sedimentary rocks. Each platform has plates and shields.

Each of the platforms has its own characteristics. The Chinese platform is fragmented into several disparate blocks, the largest of which are Chinese-Korean and South Chinese. The Siberian and Indian platforms are penetrated to the base by ancient powerful cracks and volcanic intrusions (intrusions). The basement of the East European Platform is dissected by troughs and deep depressions. The Arabian platform is split and stretched into pieces by a modern fault - a rift (see pictures on the right). The sedimentary covers of the platforms differ in thickness and in the rocks that make them up. The platforms of Eurasia are characterized by different intensity of modern tectonic movements.

Fold belts in Eurasia formed at different geological times. During ancient folding, the Atlantic and Ural-Mongolian belts were formed. Subsequently, different areas of these belts developed differently: some experienced subsidence, others experienced uplift. Those that sank were flooded by the seas, and a thick layer of marine sediments gradually accumulated on the folded base. These areas have acquired a two-tiered structure. This - young platforms , the largest of which are West European and Scythian (in Europe), West Siberian and Turan (in Asia). The areas that experienced uplifts were folded mountain systems (Tien Shan, Altai, Sayan). During the entire time of their existence, their folds (mountain ranges) were exposed to external forces. Therefore, at present they are severely destroyed, and ancient crystalline rocks are exposed on the surface.

Alpine-Himalayan and Pacific folded belts arose at a later geological time and has not yet been finally formed. They are young. The surface of the mountains, which represent these belts, has not yet had time to collapse. Therefore, it is composed of young sedimentary rocks of marine origin, hiding at a considerable depth the crystalline cores of the folds. These belts are characterized by high seismicity - volcanism is manifested here, earthquakes are concentrated. In such areas, volcanic rocks overlap sedimentary rocks or are embedded in their thickness.

Now let's move on to minerals.

Together with part of the upper mantle, it consists of several very large blocks, which are called lithospheric plates. Their thickness is different - from 60 to 100 km. Most plates include both continental and oceanic crust. There are 13 main plates, of which 7 are the largest: American, African, Indo-, Amur.

The plates lie on the plastic layer of the upper mantle (asthenosphere) and slowly move relative to each other at a speed of 1-6 cm per year. This fact was established by comparing photographs taken with artificial satellites Earth. They suggest that the configuration in the future may be completely different from the current one, since it is known that the American lithospheric plate is moving towards the Pacific, and the Eurasian one is approaching the African, Indo-Australian, and also the Pacific. The American and African lithospheric plates are slowly moving apart.

The forces that cause the separation of lithospheric plates arise when the mantle substance moves. Powerful ascending flows of this substance push apart the plates, break the earth's crust, forming deep faults in it. Due to underwater outpourings of lavas, strata are formed along the faults. Freezing, they seem to heal wounds - cracks. However, the stretch increases again, and breaks occur again. So, gradually increasing lithospheric plates diverge in different directions.

There are fault zones on land, but most of them are in ocean ridges on where the earth's crust is thinner. The largest fault on land is located in the east. It stretched for 4000 km. The width of this fault is 80-120 km. Its outskirts are dotted with extinct and active ones.

Collision is observed along other plate boundaries. It happens in different ways. If the plates, one of which has an oceanic crust and the other a continental one, approach each other, then the lithospheric plate, covered by the sea, sinks under the continental one. In this case, arcs () or mountain ranges () arise. If two plates with a continental crust collide, then the edges of these plates are crushed into folds of rocks, and mountainous regions are formed. So they arose, for example, on the border of the Eurasian and Indo-Australian plates. The presence of mountainous areas in the inner parts of the lithospheric plate suggests that once there was a boundary between two plates, firmly soldered to each other and turned into a single, larger lithospheric plate. Thus, we can draw a general conclusion: the boundaries of lithospheric plates are mobile areas to which volcanoes are confined, zones, mountainous areas, mid-ocean ridges, deep-water depressions and trenches. It is at the boundary of lithospheric plates that are formed, the origin of which is associated with magmatism.

The territory of Eurasia was formed over hundreds of millions of years. The structure of the earth's crust of Eurasia is more complex than that of other continents. Eurasia is located within three large lithospheric plates: Eurasian(most of the area) Indo-Australian(in the south) and North American(in the north-east). The lithospheric plates are based on several ancient and young platforms. ancient platforms formed in the Archean and Proterozoic eras, their age is several billion years. These are the remains of the former mainland Laurasia. These include: Eastern European, Siberian, Chinese-Korean, South Chinese. Also on the mainland there are ancient platforms that joined Eurasia later, separated from the Gondwana mainland, - Arabian(part of the African Arabian Platform) and Indian.

Young platforms in Eurasia occupy large areas. The largest of them are West Siberian and Turan. Their foundation, which is several hundred million years old, lies at great depths. That is, these platforms formed at the end of the Paleozoic era. material from the site

When lithospheric plates approached or moved apart along their boundaries, folding, volcanism, and earthquakes occurred. As a result of this, gigantic folding belts Eurasia, within which alternate high mountains and deepest depressions. In the central part of the mainland between platform areas lies an ancient Ural-Mongolian belt, within which active mountain building took place in the Paleozoic era. Young seismically active belts continue to form in the south and east of Eurasia - Alpine-Himalayan and Pacific. Numerous earthquakes occur within their borders. Recently, devastating earthquakes have occurred in Armenia in the Caucasus (1988), in Turkey on the peninsula of Asia Minor (1999), in Indonesia on the Greater Sunda Islands (2004). They claimed the lives of tens and hundreds of thousands of people. Active volcanoes are confined to young folding belts: Vesuvius. Etna, Klyuchevskaya Sopka (fig.. 168), Fujiyama, Krakatoa.

An island is located on the border of lithospheric plates Iceland (Fig. 169). This island with an oceanic type of earth's crust represents the upper parts of the North Atlantic mid-range ridge protruding above the water. As a result of the divergence of lithospheric plates, fissure-type volcanoes formed on the island. The largest of them is Hekla. Volcanism is accompanied by the appearance of hot springs and geysers.

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