What was wegeners evidence that pangea once existed

Scientists were amazed to find that the north magnetic pole changed location through time figure 6. Figure 6. The location of the north magnetic north pole 80 million years before present mybp , then 60, 40, 20, and now. Geologists noted that for rocks of the same age but on different continents, the little magnets pointed to different magnetic north poles.

The scientists looked again at the three possible explanations. Only one can be correct. If the continents had remained fixed while the north magnetic pole moved, there must have been two separate north poles. Since there is only one north pole today, the only reasonable explanation is that the north magnetic pole has remained fixed but that the continents have moved. To test this, geologists fitted the continents together as Wegener had done.

It worked! There has only been one magnetic north pole and the continents have drifted figure 7. They named the phenomenon of the magnetic pole that seemed to move but actually did not apparent polar wander.

Figure 7. On the left: The apparent north pole for Europe and North America if the continents were always in their current locations. The two paths merge into one if the continents are allowed to drift. The content on this page is copyrighted under a Creative Commons Attribution 4. Identical rocks, of the same type and age, are found on both sides of the Atlantic Ocean.

The Geological Society Plate Tectonics. Pioneers of plate tectonics What is a plate? Plate margins Plate tectonics of the UK. Fossil Evidence There are many examples of fossils found on separate continents and nowhere else, suggesting the continents were once joined.

The Mesosaurus is known to have been a type of reptile, similar to the modern crocodile, which propelled itself through water with its long hind legs and limber tail. It lived during the early Permian period to million years ago and its remains are found solely in South Africa and Eastern South America.

Now if the continents were in still their present positions, there is no possibility that the Mesosaurus would have the capability to swim across such a large body of ocean as the Atlantic because it was a coastal animal. Roaming the terrains during the Triassic period to million years ago , the Cynognathus was as large as a modern wolf. Its fossils are found only in South Africa and South America.

As a land dominant species, the Cynognathus would not have been capable of migrating across the Atlantic. Modern day representation of the Lystrosaurus. It is approximated that it grew up to one meter in length and was relatively dominant on land during the early Triassic period million years ago. In the s, scientists discovered the plate edges through magnetic surveys of the ocean floor and through the seismic listening networks built to monitor nuclear testing, according to Encyclopedia Britannica.

Alternating patterns of magnetic anomalies on the ocean floor indicated seafloor spreading , where new plate material is born. Magnetic minerals aligned in ancient rocks on continents also showed that the continents have shifted relative to one another. A map of the continents inspired Wegener's quest to explain Earth's geologic history.

Trained as a meteorologist, he was intrigued by the interlocking fit of Africa's and South America's shorelines. Wegener then assembled an impressive amount of evidence to show that Earth's continents were once connected in a single supercontinent. Wegener knew that fossil plants and animals such as mesosaurs , a freshwater reptile found only South America and Africa during the Permian period, could be found on many continents.