Earth crust

The Earth’s crust is an important layer which is extremely thin which is made up of rocks which form the outermost outer layer of our planet. It is equivalent to less than half of 1 percent of the total mass of the planet, but it plays a vital role in most of the natural cycles that occur throughout the Earth. The crust of the earth is made up of different layers, each one made up of different elements and their plates are constantly floating on different materials.

Characteristics of the earth’s crust

The main characteristics of the earth’s crust are the following:

• The crust can reach more than 80 kilometers in some places and less than a kilometer in others, so it is highly variable.
• It is made up of various types of rocks such as igneous , metamorphic, and sedimentary .
• Most of the rocks that form it originated as granite or basalt .
• It is made up of plates and they are floating .
• The crust is located below the mantle
• The upper part of the mantle is composed mainly of peridotite , a rock denser than the common rocks in the overlying crust.
• The boundary between the crust and the mantle is conventionally placed in the discontinuity of Mohorovicic , a limit defined by a contrast in seismic velocity.
• It occupies less than 1% of the volume of the Earth.
• Together with the underlying mantle it forms the lithosphere .

Formation of the earth’s crust

The earth was formed 4.6 billion years ago and when the cooling of the surface began, its crust , mantle and core also began to differentiate . The silicates having a lighter composition rose creating the mantle and the crust , and the heavier sinking shaping the core . The gases that were emanated from volcanic eruptions were what formed the atmosphere . For this reason, the earth’s crust is considered to have formed approximately 2.5 billion years ago, or earlier.

Types

Oceanic crust : The ocean covers 75 % of the planet’s surface and is thinner than the continental crust. It has three different levels: the lower or level III that borders the mantle in the Mohorovich Discontinuity and is composed of plutonic rocks. The second level or level I I of basalts is formed by rocks of volcanic origin and a thicker area formed by dikes. The level I is above the dams and is formed by a series of sediments in the middle of the sea and some terrigens near the continents where magmatic rocks are deposited.

Continental Crust : This is less homogeneous and has different origins. The predominant rocks are igneous rocks such as granite, as well as metamorphic rocks . It has more silicon and is less dense than oceanic crust. You can find quartz, oxygen, silicon, aluminum, potassium and iron among others.

Layers

There are three types of layers that make up the earth’s crust, which are:

• Sedimentary layer : Formed by sedimentary rocks located on the continents and continental shelves . This layer is made up of rocks that are part of the mountain ranges of the continents and the base of the continental shelf .
• Granite layer : It is formed by rocks very similar to granite . It is the fundamental part of the different continental zones. In it, the Conrad discontinuity is located , also called the « lithosphere channel» , which marks the limits of the granite layer and the lower basaltic layer. It is a discontinuous layer and it is floating in isostatic equilibrium on the basaltic layer.
• Basalt layer : Composed of rocks similar to basalt . It is a continuous layer around the Earth.

Movements of the earth’s crust

The movements of the cortex are of two types, orogenic and epirogenic . Orogenic movements are vertical movements and are faster causing folds (responsible for the formation of ridges), and faults , which are fractures of the crust that occur when the strata do not support the pressures, these faults can be vertical , horizontal or normal and cause earthquakes .

Depth

The radius of the earth’s crust is 6,378 kilometers in the part of Ecuador and the variation between the highest continental height and the deepest sea depth does not exceed 20 kilometers. The distance from sea level to the rigid mantle or crust is approximately 35 kilometers.

Chemical components and elements

The most important components that are found in greater quantity in the earth’s crust are:  oxygen, silicone, aluminum, calcium, iron, sodium, potassium and magnesium . The chemicals can be found in natural state as gold and sulfur compounds may be of different materials and may also be compounds of lead and copper combined with other materials. There are oxides, halides, nitrates, phosphates, and carbonates.

Minerals

In addition to the chemical elements, we can find silicate minerals such as quartz and feldspar.

Phenomena of the Earth’s crust

• Some of the phenomena that occur in the earth’s crust are the following:
  Earthquakes : movements of the earth’s crust that produce deformities in the rocks located inside the earth, affecting the surface.
• Tsunamis : movement of the marine crust creating waves of great height and power.
• Volcanic eruption : it is the passage of lava and ash from the interior of the earth to the exterior.
• Landslides : they are the product of changes in the structure of the earth.
• Landslides : falling ground due to loss of stability.
• Floods : Invasion of water either from a river, lake or sea due to heavy rainfall.
• Droughts : Deficiency in the amount of rain in a given place.

Importance of the earth’s crust

The main importance of the earth’s crust is that it is on it where life takes place and develops . The different natural processes are carried out in the bark and living beings, both plants and animals, can have a suitable place for life. It is the place where plants grow, food is grown and living things evolve.