The post-world war -II period added new information regarding the continents. In particular, the ocean floor mapping gave new dimensions in the field of study of oceans and continents.
Convectional Current Theory
The convection currents operating in the mantle portion were discussed by Arthur Holmes in the 1930s.
These currents are caused by radioactive elements in the mantle that create Thermal Differences. Holmes suggested that this force existed throughout the Mantle that was responsible for continental drifts.
Mapping of the Ocean Floor
The ocean floor consists of not only floors or plains and consists of reliefs, mountains, etc just like what that in lands.
The survey of the ocean floor started after world war-2, which gave results such as the existence of mountains, deep trenches were mostly closer to continent margins.
The volcanic eruption is mostly active, found at the mid-oceanic ridges. From the result of dating, the result is that the rocks from the oceanic crust are much younger than the continental areas.
The age and constituent of rocks are almost the same for the rocks of two sides of the crest of oceanic ridges and equidistant from the crest location.