Get premium membership and access revision papers with marking schemes, video lessons and live classes.

Processing. Please wait.

Explain the meaning of the following terms:
(a) Plate tectonics
(b) Continental drift
(c) Isostasy

Answer Text:
(a) Plate tectonics:
The term Plate Tectonics refers to the theory that explains the major geological structures of the earth in terms of the relative movements of rigid crystal blocks or plates of lithospheres across the partially fluid Asthenosphere.
(b) Continental drift:
The term continental Drift refers to the supposed horizontal displacement of portions of the original continent (the Pangaea) which comprised the entire land mass of the world to form the present day continents.
(c) Isostasy:
The term Isostasy refers to the state of equilibrium that
is said to exist between the highlands and the lowlands of the earth, due to the fact that the former are made of lighter rock materials than the latter.
According to the theory of Isostasy known as the Isostatic theory, the continental platforms are made up of lighter material and are, as it were floating
at a higher level than the material of the ocean floor