The core, mantle and crust are the internal structure of the Earth. And what is the lithosphere? This is the name of the outer solid inorganic shell of our planet. It includes the entire 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 debate about its composition is also ongoing. But according to available information, one can still make up the basic idea of 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 this is expressed only in 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 from what material it is formed, in what condition it is in different parts.
The main part of the shell is made up of hard rocks, which at the boundary with the mantle acquire a plastic consistency. Stable platforms and folding areas are distinguished in the crust structure.
The earth's crust has a different thickness and can range from 25 to 200 kilometers. On the ocean floor it is thinner - from 5 to 100 kilometers. The lithosphere of the Earth is limited by other shells: the hydrosphere (water) and the atmosphere (air).
The crust is composed of three layers:
- sedimentary;
- granite;
- basaltic.
Thus, if you look at what the lithosphere is in the context, it will resemble a layer cake. Basalt is its basis, 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 alteration of granite and basalt rocks. On the ocean floor, such stratification is formed as a result of the accumulation of sedimentary rocks carried by rivers from continents.
The 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 is basalt, consisting of igneous rocks.
The earth's crust is not a monolith, it consists of individual blocks called lithospheric plates, which are in constant motion. They seem to float on the plastic asthenosphere.
During its existence, humanity in economic activity has constantly used the components 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 pressing problems requiring immediate solution.
Some processes occurring within the boundaries of the shell, for example, erosion, landslides, mudflows, can be caused by anthropogenic activity and pose a threat. They not only affect the formation of environmental situations in certain territories, but can also lead to global environmental disasters.
