The theory of plate tectonics states that
A)the lithosphere is broken up into several plates that move about as a result of convective motion in the asthenosphere.
B)earthquakes and volcanic activity result from convection motion in the lithosphere.
C)buoyant lithospheric plates float on top of the rigid asthenosphere.
D)the plates move in conveyor-belt fashion as new crust is generated at the continental margins and destroyed at the mid-ocean ridges.

Question

Quizplus · Accepted Answer

The theory of plate tectonics states that the lithosphere is broken up into several plates that move about as a result of convective motion in the asthenosphere. This is the main idea of the theory and is supported by various pieces of evidence, including the distribution of earthquakes and volcanic activity along plate boundaries, the ages of rocks on either side of mid-ocean ridges, and the magnetic orientation of rocks on the seafloor.

Option B is incorrect because earthquakes and volcanic activity are a result of plate movement, not convection motion in the lithosphere. Option C is partially correct, but the buoyancy of the plates is due to their composition and thickness, rather than their ability to float on the asthenosphere. Option D is also partially correct, but it does not explain the driving force behind plate motion (which is convection in the asthenosphere).

The Theory of Plate Tectonics States That