The core, mantle and crust are the internal structure of the Earth. What is the lithosphere? This is the name of the outer solid inorganic shell of our planet. It includes the entire earth's crust and the upper part of the mantle.
In a simplified form, the lithosphere is the upper layer of the Earth, consisting of three layers. In the scientific world there is no unambiguous definition of the concept of this planetary shell. And the debate about its composition is still ongoing. But according to the available information, it is still possible to draw up basic ideas about what the lithosphere is.
Structure, composition and borders
Despite the fact that the lithosphere covers absolutely the entire earth's surface and the upper layer of the mantle, in weight equivalent it is expressed in only one percent of the total mass of our planet. Although the shell has small volumes, its detailed study raised a lot of questions, and not only about what the lithosphere is, but also what material it is formed from, what state it is in in different parts.
The main part of the shell is made up of solid rocks, which acquire a plastic consistency at the boundary with the mantle. Stable platforms and regions are distinguished in the structure of the earth's crust.folding.
Earth's crust has a different thickness and can vary from 25 to 200 kilometers. On the ocean floor, it is thinner - from 5 to 100 kilometers. The Earth's lithosphere is limited by other shells: the hydrosphere (water) and the atmosphere (air).
The earth's crust is composed of three layers:
- sedimentary;
- granite;
- bas altic.
Thus, if you look at what the lithosphere is in the context, it will resemble a layer cake. Its basis is bas alt, and on top it is covered with a sedimentary layer. Between them, in the form of a filling, there is granite.
The sedimentary layer on the continents was formed as a result of the destruction and modification of granite and bas alt rocks. On the ocean floor, such a layer is formed as a result of the accumulation of sedimentary rocks carried by rivers from the continents.
Granite layer consists of metamorphic and igneous rocks. On the continents, it occupies an intermediate position between other layers, and at the bottom of the oceans, it is completely absent. It is believed that in the very "heart" of the planet there is bas alt, consisting of igneous rocks.
The Earth's crust is not a monolith, it consists of separate blocks called lithospheric plates, which are in constant motion. They seem to float on the plastic asthenosphere.
Ecological problems of the lithosphere
During its existence, mankind in economic activityconstantly used the constituent parts of the lithosphere. The earth's crust contains all the mineral resources that are widely used by people, and their extraction from the bowels is constantly increasing.
The soil is of great value - the preservation of the fertile layer of the lithosphere today is one of the most urgent problems that require immediate solutions.
Some of the processes occurring within the boundaries of the shell, such as erosion, landslides, mudflows, can be caused by anthropogenic activities and pose a threat. They not only influence the formation of ecological situations in certain territories, but can also lead to global environmental disasters.
