During his studies, he managed to gather geographical, geological and paleo-climatic, paleontological proofs that supported his theory, although later it was discarded by scientists. The theory of continental drift is and has been important because it has helped scientists explain the different formations of mountains and mountain ranges.
It also managed to change the perspective of how the world began, because at first, it was thought to have originated from a large fused mass. Continental drift. Geography Continental drift. Related topics Geographical space , orography , continental shelf , cardinal points. This theory is called catastrophism, according to the USGS. Plate tectonics is now the widely accepted theory that Earth's crust is fractured into rigid, moving plates.
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. He suggested that Pangaea broke up long ago and that the continents then moved to their current positions. He called his hypothesis continental drift.
Besides the way the continents fit together, Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. For one, identical rocks of the same type and age are found on both sides of the Atlantic Ocean.
Wegener said the rocks had formed side-by-side and that the land had since moved apart. Mountain ranges with the same rock types, structures, and ages are now on opposite sides of the Atlantic Ocean. Wegener concluded that they formed as a single mountain range that was separated as the continents drifted.
Ancient fossils of the same species of extinct plants and animals are found in rocks of the same age but are on continents that are now widely separated. Wegener proposed that the organisms had lived side by side, but that the lands had moved apart after they were dead and fossilized.
He suggested that the organisms would not have been able to travel across the oceans. For example, the fossils of the seed fern Glossopteris were too heavy to be carried so far by wind. The reptile Mesosaurus could only swim in fresh water. The theory of plate tectonics revolutionized the earth sciences by explaining how the movement of geologic plates causes mountain building, volcanoes, and earthquakes.
Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. Continental drift describes one of the earliest ways geologist s thought continent s moved over time. Today, the theory of continental drift has been replaced by the science of plate tectonics.
The theory of continental drift is most associated with the scientist Alfred Wegener. He called this movement continental drift. Wegener, trained as an astronomer , used biology , botany , and geology describe Pangaea and continental drift. For example, fossil s of the ancient reptile mesosaurus are only found in southern Africa and South America. Mesosaurus, a freshwater reptile only one meter 3. The presence of mesosaurus suggests a single habitat with many lakes and rivers. Wegener also studied plant fossils from the frigid Arctic archipelago of Svalbard, Norway.
These plants were not the hardy specimen s adapt ed to survive in the Arctic climate. These fossils were of tropical plants, which are adapted to a much warmer, more humid environment.
The presence of these fossils suggests Svalbard once had a tropical climate. Finally, Wegener studied the stratigraphy of different rocks and mountain range s. South America and Africa were not the only continents with similar geology.
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