Continental drift

From Palaeos.org

Continental drift is a theory advanced particularly by Alfred Wegener that tried to explain the fact that coastlines of land masses at opposite ends of for example the Atlantic ocean match each other in shape. The coastlines of Greenland and Norway are a good example

This remarkable fact had undoubtedly been noticed by generations of school children as long as reasonable maps had been available, but an explanation was lacking. Actually comparison is not limited to the shape of the coast line but also stretches to the geological features at either side of it. The opposite can be said about mountain ranges that seemed to be sutures between two disparate land masses.

Wegener proposed that these remarkable observations were the result of the drifting apart of continents that has once been connected or -in the case of mountain ranges- of the collision of two land masses. Unfortunately for his theory he could not come up with a credible mechanism for the movement of whole land masses over distances of thousands of mile. The geological community largely derided his theory. In an attempt to actually measure the movement of Greenland away from Northern Europe Wegener lost his life.

After his death there were few scientist that even dared to continue his line of thinking. A notable exception was the South African Du Toit who investigated the continuity of the layers of his homeland with those of the opposite landmass South America. Even though his work showed even more striking resemblances, main stream geology would not hear of his findings and until the early 1970s it was not unusual for European students of Geology to be taught that continental drift was pseudoscience.

Then Wegener was vindicated. Methods to study the bottom of the oceans became available and these showed very clearly that the crust of the Atlantic ocean was youngest at the mid-oceanic rift. Sideways from there new oceanic crust is constantly being produced, widening the Atlantic ocean and pushing Norway and Greenland, Argentina and South Africa farther apart. This time Geophysics did come up with a credible mechanism involving convection currents in the Earth's mantle. The new theory, successor to continental drift, is known as plate tectonics.