Chapter 5 - Section 3 - Drifting Continents Flashcards
continental drift
The theory that the continents slowly move across Earth’s surface
Pangaea
The name of the single landmass that broke apart 200 million years ago and created today’s continents.
fossil
A trace of an ancient organism that has been preserved in rock.
What was Alfred Wegener’s hypothesis (theory) about the continents?
His hypothesis was that ll the continents were once joined together in a single landmass and have since drifted apart.
What evidence supported Wegener’s hypothesis?
Mountains and other features on the continents provided evidence.
For example, when Wegener pieced together maps of Africa and South America, he noticed that mountain ranges on both continents line up.
He noticed that European coal fields match up with coal fields in North America.
Why was Wegener’s hypothesis rejected by most scientists of his day?
Because he could not identify the cause of continental drift.
How would continental drift affect a continent’s climate?
As a continent moves toward the equator, its climate becomes warmer.
According to Wegener, how do mountains form?
when continents collide and their edges crumple and fold
Who proposed the concept of continental drift?
Alfred Wegener
How do fossils provide evidence of continental drift?
When the continents drifts, it carries with it the fossils and rocks that formed at its previous locations.
For example, fossils of tropical plants are found on Spitsbergen, an island in the Arctic Ocean.
When these plants lived about 300 million years ago, the island must have had a warm and mild climate. According to Wegener, Spitsbergen must have been located closer to the equator.
