How does plate tectonics work? What is plate tectonics theory

Plate tectonics, on the basis of continental drift and seafloor expansion, people began to combine and unify the study of continental geology with the study of marine geology. Trying to find out the essential connection between them. This gave rise to the theory of plate tectonics.

The first to introduce the idea of plate tectonics to China was Yin Chanxun, an old-timer in the geological community, in 1972. The basic content of plate tectonics, the solid earth can be vertically divided into two spheres with very different physical properties: the upper rigid lithosphere and the lower plastic asthenosphere. The lithosphere can be divided into plates of various sizes laterally.

The plates are bounded by ocean ridges, trenches, conversion faults, and ground sutures. Plate boundaries are zones where volcanic and tectonic activity is concentrated. Lithospheric plates move horizontally on a large scale on the Earth's surface.

The ocean ridge expands and accretes, and the trench compresses and dies to keep the surface area unchanged. The driving force for plate movement comes from mantle convection in the Earth's interior. Plate motion is also not horizontal motion, it is a rigid body sinking spherical motion.

The theory of plate tectonics is based on the theory of continental drift and the theory of seafloor spreading. According to this new theory, the Earth's surface is covered with undeformed and solid plates (lithosphere) that are indeed moving at a rate of 1 cm to 10 cm per year. Since the Earth's surface area is finite, the Earth's plates are classified into three states:

One is the converging plate boundaries that are close to each other; the second is the detached plate boundaries that are far away from each other; The third is the intertwined transition plate boundaries. The plates themselves do not deform, and the earth's surface activities occur intensively in these three states. The theory of plate tectonics is a new theory of continental drift proposed by French geologists Le Pichon in 1968, Mackenzie, Morgan and others, which is a specific extension of the theory of seafloor expansion.

Plate tectonics, also known as global tectonics.

The term "plates" refers to lithospheric plates, including the entire crust and the top of the upper mantle below the Moho surface, that is, the top of the mantle above the crust and asthenosphere. The new global tectonic theory holds that large-scale horizontal movements have occurred and continue to occur in both continental and oceanic crusts. However, this horizontal movement does not occur between the silicon-aluminum and silicon-magnesium layers, as the continental drift theory envisions, but rather the lithospheric plates move like a conveyor belt along the entire mantle asthenosphere, and the continents are only "passengers" on the conveyor belt.

The discovery of giant terrestrial planets outside our solar system has been named "SuperEarth". "Super-Earths" have sparked a great interest among scientists to study where they might be like Earth. In 2014, Harvard scientists pointed out that these terrestrial planets also apply to the theory of Earth's plate tectonics.

The theory of plate tectonics refers to the theory of the movement of the huge plates that make up the solid outer shell of the earth. Plate movements often lead to **, volcanoes, and other large geological events. Essentially, plates determine the geological history of the Earth.

Earth is the only planet known to lend itself to the theory of plate tectonics. The movement of the Earth's tectonic plates is considered to be a necessary condition for the evolution of life. <>

Plate tectonics, the top layer of the earth, including the earth's crust, is about 100 kilometers of the lithosphere is incomplete, like breaking the eggshells that are still connected, these rock layers of different sizes, spliced together are called plates, they each float and move on the asthenosphere in the upper mantle, and some plates will subduct to hundreds of kilometers deep in the mantle. There are six largest plates on Earth, namely the Pacific Plate, the Eurasian Plate, the American Plate, the African Plate, the Indian Ocean Plate, and the Antarctic Plate. There are also smaller plates, such as the Philippine plate.

The plates are in constant motion, and the collision of continental and oceanic plates creates ocean trenches. The relationship between plate tectonics and activity can be clearly seen to be very consistent when comparing the world's distribution with the global plate distribution. According to statistics, 85% of the world's ** occurs on plate boundaries, and only 15% of ** have less obvious relationships with plate boundaries.

This shows that the interaction in the process of plate movement is an important reason for the occurrence of the plate. <>

Plate tectonics theory: plate tectonics theory is often used to cause the movement of the earth's crust, the earth has been in the surface and interior since its formation in a never-ending motion change, the earth's surface morphological characteristics are the result of the earth's internal and external forces.

Through decades of rapid development, the theory of plate tectonics has completely shaken the traditional geological theory. With the development and improvement of theories, these assumptions have undergone a certain degree of revision and expansion, and this evolution history is the condensation of the development of the geoscience community over the years. At the same time, there are many deficiencies and characteristics that are difficult to verify in the age of plate tectonics.

The initial simple but strict assumptions of plate tectonics theory were that both the rigid and elastic lithosphere were plastic soft sparrow flowrings, that the lithosphere was divided into a small number of large plates, that there were three interactions between these plates in strict accordance with Euler's theorem, that plate subduction and expansion compensated for each other in perfect unison, so that the volume of the earth remained constant, and that the direct condition for plate movement was convection in the asthenosphere.

Plate tectonics theory is a tectonic theory formed in the late 60s, which is a further development of the theory of continental drift and seafloor expansion. It is a summary and summary of the global crustal activity pattern on the basis of a large number of recent research results in marine geology, seabed geomorphology and geophysics.

Plate tectonics is a new global tectonic theory proposed in the 60s of the 20th century. The theory of plate tectonics was developed on the basis of the theory of continental drift and the theory of the expansion of the sea.

The theory of plate tectonics holds that the basic tectonic unit of the lithosphere is the plate; The plate boundaries are mid-ocean ridges, conversion faults, subduction zones, and ground sutures; The basic cause of global crustal tectonic movement is the interaction of these plates; The plate is very strong, and the edge of the plate is where the tectonic movement is most intense, and the main deformation is in its edge part.

The difference between plate movement and continental drift:

1. Wegener et al. only contain the continental silicon-aluminum layer on the mainland; In the plate theory, lithospheric plates contain the lithosphere (lithospheric mantle) above the earth's crust and asthenosphere.

2. Wegener and others regard the continent as an active unit, while the continent is passive in the plate theory. The continental drift theory holds that the continents drift through the subcrustal silicon-magnesium layer; The plate theory introduces the concept of passive continents carried on a conveyor belt. Due to their low density in composition, they are usually more buoyant and can escape the fate of being reduced, becoming a stable passive buoyancy block on the conveyor belt.

3. Wegener et al. regard the continental silicon-aluminum layer as something completely different from the silicon-magnesium layer of the earth's mantle; The plate theory holds that the land is a chemical product of the mantle differentiation and floating, and the land is linked to the part of the mantle below.

1. Since the formation of the earth, the earth has been in a never-ending movement and change on the surface and inside, and the morphological characteristics of the earth's surface are the result of the comprehensive action of the earth's internal and external forces, among which the internal force is an important reason for the formation of the earth's surface difference. **The causes of crustal movement need to be explained by tectonic theory.

2. Plate tectonics is a new global tectonic theory put forward in the 60s of the 20th century, and due to the emergence of new theories of plate tectonics, earth science has made breakthroughs and is of great significance. At present, the theory of plate tectonics has become the main theoretical framework for the synthesis of multidisciplinary achievements, and has become the latest popular and generally accepted theoretical form in modern times.

Since the 60s of the century, the phenomenon of seafloor expansion has been confirmed, and the hypothesis of continental drift has been widely recognized. In 1965, scientists used computers to make the earth's continents fit together in their current shapes, and connected Haiti's topography, location, volcanoes and other active parts into a belt.

4. Thus, it is hypothesized that continental drift and seafloor spreading may manifest as the mutual movement of several lithospheric plates. In 1968, Le Pichon of France (W. Morgan of the United States). j.

Scholars such as Morgan and McKenzie in the United Kingdom developed the concept of continental drift and seafloor expansion into the famous "plate tectonics theory" based on many new geological phenomena that had been discovered at that time. After the theory of plate tectonics was proposed, it was continuously improved by many scientists, and was soon endorsed by other geoscientists. The development of modern earth science has entered a revolutionary period marked by the establishment of plate tectonics.

Answer: The main point of view of the "plate tectonics" theory: the earth is divided into large plates, and then subdivided into small plates in each plate, and their mechanical theory and motion mode are mainly drifting and colliding based on horizontal motion, and then producing upward and downward motion.

Their mode of action of compressive stress is mainly the interaction of main compressive stress, assertion stress and torsional stress.

Their stresses vary unevenly from the Earth's rotation rate.