What was the main limitation of Wegener's theory?

Wegener's theory of continental drift proposed that continents were once part of a supercontinent called Pangaea and have since drifted apart. A significant limitation of this theory was that Wegener could not provide a convincing mechanism to explain how the continents moved. This absence of a mechanism meant that his idea lacked a solid scientific basis, which hindered its acceptance by the broader scientific community at the time. Without an understanding of the forces that could cause the plates to shift, critics found it challenging to support the theory, leading to skepticism about the validity of continental drift.

Understanding the mechanisms of plate tectonics, which were established later with the development of plate tectonic theory, provides clarity on why Wegener's initial hypothesis was not fully embraced in his time. This advancement included identification of processes like seafloor spreading, subduction, and mantle convection, which ultimately led to a comprehensive understanding of how tectonic plates move.