Plate tectonics is a modern geoscience theory. It originated in the 1960s. Plate tectonics believe that the Earth's surface (lithosphere) is a huge plate thickness of about 100-150 km composition, the global lithosphere can be divided into six plates, the Pacific plate, the Indian Ocean plate, the Asia-Europe plate, the African plate, Antarctica plate, in which only the Pacific plate is almost entirely in the ocean, the rest include the mainland and the ocean. The dividing line between the plates is the ridge,trench, large folded mountains and rift and transition fault zones. The theory of geological geography and biology great influence. Distribution of strata, minerals, fauna and flora on different continents can only be explained by the theory of plate tectonics.
There are three possible forms of motion:
The first is the formation of a new plate, which is generally deposited on the seafloor at the plate boundary or at the edge, due to lava pouring and cooling to create a new plate, but if there is land above the plates, the land follows In the case of relative motion, this edge may start with a break in the middle of the continent. For example, the Great Rift Valley in East Africa is an example of the early stages of the two plate separations, when the two parts of the mainland completely separated, the water will flood the fault part, and then form a new ocean. At the beginning of the separation, the two land had the same plant and animal fauna, and the extinction of the original species and the evolution of the new species led to changes in the flora and fauna of the two land masses.
The second form of plate movement is relative plate movement, if one or both plate edges are thin marine rock shell, then, one plate may slide to another, when the two plates move together, they are Between the friction caused by puncture and strenuous exercise, resulting in seismic belt. The ocean sinking rock crust moves deeper into the crust, melts as it approaches the deep core of the hot core, and then melts the magma out of the earth's surface, creating volcanic eruptions. If the two plates carry the continent, then they will approach each other. The continental crust is less dense than the oceanic crust, so that if a continent approaches the edge of a subsidence plate, it will not slide underneath the other rock crust, thus preventing subsidence beneath it. If the two plates each have a land, collide with each other will not collapse concessions, the impact of the results of the formation of long mountains. The Himalayas are the highest mountains in the world and are still rising slowly due to the collision of the Indian plate and the Eurasian plate between 4000-4500 million years ago.
The third is the collision of the plate edges, the San Andreas fault in California showing the Pacific plate sliding north and the North American plate sliding south.
It can be seen that the continent was formed by a supercontinent of the ancient continent known as Pangea, which was divided in half by about 200 million years ago, half by Laurasia and the other by Gondwanaland. Once the continents are divided into different land masses, they are separated from each other by the vast sea, and the animals and plants on each continent are isolated, and the results of their independent evolution lead to different biogeographical patterns.
Since the Himalayas, the Chinese plate mainly by the Indian plate north, the Pacific plate mainly west and Siberia plate south of the three driving force. In these blocks of the southwest, east and north of the three directions gradually accretion accretion, until the Himalayan period to form today's mainland China and coastal continental shelf area. The formation of oil and gas-bearing sedimentary basins is closely related to plate movement. China's western region has long been subjected to collisional compression from the South and North plates, and is a convergent continental margin. Forming a compression type mountain or plateau sedimentary basin. The eastern part of the Pacific plate by the west subduction role, as the expansion of the continental margin activities.
Source: Atlas of China's Natural Disaster System
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