Plate tectonic theory: The theory of plate tectonics is the theory based on the volcanic phenomena, seismic surveys, and sea floor spreading. This principle is credited to Harry Hess. The term plate was first used by Tuzo Wilson.
Plate tectonics: According to the theory of plate tectonics, all the lithosphere is divided into 6 large and 20 small plates. These plates continually engage in convergent, upside down and rubbing movement in the context of each other, by which tectonic function occurs. The complete transit of plates is called the plate tectonics.
Major plates and minor plates: The entire earth surface is divided into six main plates : Indian plate, Eurasian plate, American plate, African plate, Antarctic plate and Pacific plate. The minor plates mainly include the Juan – de – Fuca Plate, Cocos Plate, Nazca Plate, Caribbean Plate, Scotia Plate, Arabian Plate, Philippine Plate, North American Plate, Southern American Plate, Indo – Australian Plate, etc.
These main and minor plates found in the world are displayed through the following diagram:
Types of plates:
Plates are of three types depending on their structure:
1. Continental Plate.
2. Ocean Plate.
3. Ocean – Continental Plate
.Plate edges – all the tectonic functions are concluded with the help of these plate edges.
These plates margins are of three types on the side is:
1. Constructive Plate Margins: When two plates are deflected, due to the occurrence of empty space, the magma gets out and accumulates in the form of lava, resulting in regional expansion. Such edges have constructive plates on the side.
2. Destructive Plate Margins: When two plates are convergent, one plate climbs over the other and the other plate undergoes ablation. The front edge of the avalanche plate melts when it breaks into the mantle. Hence, they are known as destructive plate margins.
3. Protective Plate Margins: When two plates move along, neither the plate gets eroded nor new materials are created there, so they are called protective plate margins.
