In the 1930s, which of the following theories was propounded by Arthair Holmes about the mantle?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. Convectional Current Theory.
In the 1930s, Arthur Holmes proposed the theory of convection currents in the mantle, which is often referred to as the Convection Current Theory. This theory was a significant contribution to the understanding of plate tectonics and the movement of the Earth's lithospheric plates.
-
Convection Currents: Holmes suggested that the Earth's mantle behaves like a viscous fluid, and heat from the Earth's core causes the mantle material to rise toward the surface. As it moves upward, it cools and sinks back down, creating a continuous convective flow.
-
Mechanism for Plate Movement: This circulation of mantle material is believed to drive the movement of the Earth's tectonic plates. The theory proposed that convection currents in the mantle push and pull the plates, causing them to move and interact at their boundaries (leading to phenomena like earthquakes, volcanic activity, and the formation of mountain ranges).
-
Support for Continental Drift: Holmes’ theory helped explain the mechanism behind the movement of continents, providing support for the earlier ideas of Alfred Wegener's Continental Drift Theory.