What are the principles of the plate tectonics theory?


What are the principles of the plate tectonics theory?

Plate tectonic theory:

Plate tectonic theory describes the dynamic nature of the tectonic plates that together makes up the earth's lithosphere. There are around seven major tectonic plates and several minor plates that comprise the lithosphere. The theory of plate tectonics is the foundation of modern geology that merges the concept of continental drift and seafloor extension together.

Answer and Explanation:

The basic principles that underlie the tectonic plate theory include several key concepts:

  • The outer shell of the earth is called the lithosphere. It is made up of large pieces of solid rocks called plates. The lithosphere comprises of both the upper crust and the upper mantle. The lithosphere can further be classified as the continental crust or the oceanic crust. Oceanic crust is thinner yet denser than the continental crust.
  • Tectonic plates are floating on the asthenosphere, the upper part of the earth's mantle, which is called the plastic layer due to its molten state.
  • The inner mantle of the earth generates convection currents due to the intensely heated core of the earth. The convection currents are due to the continuous rising of hot molten rocks and its subsequent sinking upon cooling within the mantle. This convection current of heat melts the asthenosphere and causes the tectonic plates to drift by its forces.

Learn more about this topic:

Plate Tectonics: Theory & Definition

from General Studies Earth & Space Science: Help & Review

Chapter 7 / Lesson 5

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