Question #a659a

1 Answer
Jan 3, 2018

Similar geology and fossils


The continental drift hypothesis is based on the idea that the continents were once all grouped in a single landmass and that moved to their actual positions pushed by continuous expansion of oceanic basins opening between them.

Multiple cues are available to support the hypothesis:

  • The geological structures across continents now divided by large oceans are often the same allowing for continuity in the strata. As example there are similar deposits in South America and Africa and Canada and North Europe.

  • Fossils of creatures that cannot cross water have been found on landmasses now separated by oceans.

  • The morphology of the continental shelf in several cases resemble the one of a large puzzle with matching shapes across the oceans. Typically the shape of Africa and South America.

  • In some rocks there is the trace of ancient magnetization showing that these lands drifted in relation to the poles.

  • Ocean expansion is a proved fact with fresh oceanic crust being continuously produced at the middle-ocean ridges that are chain of submerged active volcanoes.

It is likely that the continents went through several cycles of breaking apart and reforming a single super-continent during the planet lifetime.