What was the main reason Wegener’s continental drift hypothesis was rejected?
The Correct Answer and Explanation is:
Correct Answer:
Wegener could not explain the mechanism that caused the continents to move.
Explanation:
Alfred Wegener’s hypothesis of continental drift, proposed in the early 20th century, suggested that Earth’s continents were once joined together in a single landmass called Pangaea. Over time, he believed, this landmass broke apart, and the continents drifted to their present locations. He supported his theory with evidence such as the fit of the coastlines of South America and Africa, the distribution of fossils across continents, similarities in rock formations, and ancient climatic patterns.
Despite the strength of his observational evidence, Wegener’s idea was not widely accepted by the scientific community during his lifetime. The main reason for this rejection was that Wegener could not provide a convincing mechanism for how the continents could move across the Earth’s surface. At the time, the leading theories in geology held that the Earth’s crust was rigid and immobile, and there was no known force strong enough to move entire continents.
Wegener proposed that the continents might plow through the oceanic crust, driven by forces such as Earth’s rotation and tidal forces. However, physicists and geologists of the time demonstrated that these forces were far too weak to cause such massive movements. Furthermore, Wegener was not able to show evidence of how the continents interacted with the ocean floor during their supposed movement.
It was only decades later, with the development of the theory of plate tectonics in the 1960s, that his hypothesis gained renewed support. Plate tectonics provided a clear mechanism for continental movement based on the motion of large plates in the Earth’s lithosphere driven by mantle convection. This new understanding validated much of Wegener’s original hypothesis and established the foundation for modern geology.
Thus, Wegener’s failure to identify a credible force driving continental drift was the main reason his hypothesis was originally rejected.
