CONVECTION CURRENT THEORY…

 Convectional Current Theory talked about the possibilities of mantle convection currents. Radioactive elements in the mantle cause thermal variations, which generate these currents. In the 1930s, Arthur Holmes proposed this Theory.

According to Holmes, the entire mantle region contains a system of similar currents. This was an attempt to explain the question of force, which led to the rejection of the continental drift theory by contemporary scientists as Alfred Wegener was unable to explain the reason for the movements of plates in the western direction.

Conventional Current

• Convection is a heat transfer process that involves the movement of fluids between various temperature zones.
• A convection current is a process in which energy is transferred from one location to another. It is also known as convection heat transfer.
• Convection currents cannot occur in solids.
• Reason: The particles within the solids cannot easily flow, and most of the free movement is due to a difference in density generated by a large heat transfer between the plates.

Convectional Current Theory

• In the 1930s, Arthur Holmes proposed the Convectional Current Theory. Convection Current Theory is the soul of Seafloor Spreading Theory.
• According to this theory, the extreme heat generated by radioactive chemicals in the mantle (100-2900 km beneath the earth's surface) seeks a way to escape and causes convection currents to emerge in the mantle.
• Under the solid lithosphere, the fluid asthenosphere circulates as convection currents.
• Divergent convective currents pull crustal blocks away from each other in opposite directions, forming seas and oceans. East Africa's lakes system, the Mid-Atlantic Ridges, and so on are examples.
• Convergent convective currents generate subsidence in the crustal zones, resulting in geosynclines and sea closure, resulting in the construction of island arcs, mountains, and other features.
• Convection currents run through the mantle's molten rock, acting as a conveyor belt for the plates.
• The total change in the lithospheric materials is constant since these currents are closed in nature.

Criticism of Convectional Current Theory

Criticism of Convectional Current Theory

• The entire process of convection currents is based on heat generated by radioactive materials in the substratum (now mantle), however numerous scientists have questioned whether the needed amount of heat generated by radioactive elements is available.
• Convective currents may not be formed if heat is insufficient, and so the entire mechanism and working of the theory will be impossible. It's also worth noting that rising currents condense their heat into the crust.
• This process also results in heat loss, which could cause currents to weaken.
• Because of a lack of heat to generate these currents, the horizontal flow of thermal convection currents beneath the continental and oceanic crusts is likewise a dubious phenomenon.
• If the convergent movement of convective currents cannot flow horizontally, the descending column will not exist, and the mountain will not develop.

Conclusion

Conclusion

It can be concluded that A. Holmes' theory of thermal convection currents, which he developed roughly 80 years ago, demonstrated its utility in the 1960s, when scientists were hunting for a force that might explain plate movement. Now, the process of mountain formation may be satisfactorily explained using convective currents, though not in the way that A. Holmes envisioned in 1928-29, but rather along the lines of plate tectonics.