The Earth's crust is made up of two varieties: one called oceanic crust and another called continental crust.
The Earth's crust is the outermost, thinnest and most superficial part (zone or layer) of the Earth , the planet we inhabit. As a consequence of different geological processes, two varieties of crust have been formed that differ from each other in terms of physical properties and chemical composition: one of them is the continental crust , the other is known as the oceanic crust .
As has been established, the crust has less density than the mantle and is therefore located higher than it, constituting the highest strip of the lithosphere , exceeding the limit called the Mohorovicic discontinuity . In it, the Geology experts detail, internal processes occur that generate relief based on the action of an earthquake or a volcano and external processes in which gravity and the energy that comes from the sun intervene, causing erosion to accelerate. , the transport of fragments and sedimentation with the consequent modifications of the landscape.
Composition of the earth's crust
The composition of the Earth's crust includes a large percentage of metamorphic rocks , sedimentary rocks , and igneous rocks . There is also slate and, to a lesser extent, sandstone and limestone .
In the oceanic crust, gabbro , diabase and basalt are usually detected, while in the continental crust, rocks of a lower density appear, such as granite . In the continental crust , the most abundant mineral group is feldspar , without overlooking the presence of quartz or pyroxenes .
The deeper you go, the higher the temperature in the crust , although it must be taken into account that the geothermal gradient is smaller at greater depths.
Primary magma is formed from rocks located in the mantle or Earth's crust that fuse under optimal conditions of pressure and temperature.
Earth Structure
The structure of the Earth includes an inner terrestrial core, an outer core, a mantle and the most superficial covering that we present above under the name of crust .
The Earth's crust , which is divided into continental crust and oceanic crust , is segmented into tectonic plates . There is a theory, called plate tectonics , that aims to explain how the lithosphere is structured, addresses the movement of tectonic plates and focuses on the process classified as orogenesis , for example.
It is interesting to know, in the same way, that the asthenosphere is located in the upper portion of the mantle: each tectonic plate moves precisely over this area in which key movements are recorded to understand what continental drift is about. An extrusion process drives the basalt contained in the asthenosphere throughout the entire length of each oceanic ridge , thus allowing the ocean floor to constantly renew and expand. The area of the mantle below both the lithosphere and the asthenosphere that is located above the outer core , on the other hand, is called the mesosphere . If we focus on the layers of the atmosphere , the mesosphere would be the one that appears in third place, surpassing the stratosphere but falling below the thermosphere .
Other data of interest in structural matters: the solid and external part of the Earth , fractured into multiple tectonic plates , is located at the lower margin of the layer known as lithosphere and has been described as a Gutenberg discontinuity . The case of the Lehmann discontinuity is different, since it refers to the segmentation that divides the inner and outer nuclei.
When tectonic plates collide and other geological processes take place, mountains emerge at different points on the Earth's surface.
Disciplines that focus on the Earth's crust
There are a lot of disciplines that focus on the Earth's crust, allowing multiple types of knowledge to be obtained and giving space to interpretations, analysis, studies and research.
Geophysical experts, for example, analyze our planet from a physics-focused perspective. In its internal branch, disciplines such as geothermal science are deployed (emphasizing how heat spreads within the Earth ), geodynamics (specializing in factors that make the lithosphere and mantle move) and seismology (in charge of examining the structure terrestrial internally, encompassing telluric movements and plate displacement). External geophysics , on the other hand, draws on climatology , meteorology , oceanography , gravimetry , paleomagnetism , etc.
Of utmost importance, in turn, is the work carried out from geochronology to establish the antiquity and the gradual succession of transcendent geological events over the years. The radiometric dating technique applied by geochronology , as well as exploration and prospecting methods, are also necessary and useful.
Topography (aimed at graphically representing the Earth's surface), cartography (whose result and object of study are maps), hydrogeology (concentrated on issues alluding to groundwater), geodesy (a determining science for learning about the and the dimensions of our planet taking advantage, for example, of the GPS system or other satellite technology in order to deploy topographic support networks), stratigraphy (focused on rocks) and paleontology (oriented to the fossil universe) are other sources of knowledge and encouragement to never stop investigating the history, characteristics and evolution of the structure of the Earth .