CDT Quiz-The CDT & PTT Flashcards
Who was Alfred Wegener?
A German metorlogist who proposed the CDT in 1912
What was the Continental Drift Theory?
CDT-the thoery that once all continents where connected togther in a supercontinent call Pangea (Greek-“all land”). The continents then broke apart and drifted to thier present-day locations.
What was the main weekness with the CDT?
Wegener was unable to explain HOW the continents moved.
What did many people believe in 1912?
That Earth was static (continentis didn’t move)
What did Wegener proposse as the reason continenits moved?
Wegener thought that tides hitting the continents might make them move
What was Wegener’s evidence for the CDT, regarding that shape of the continents?
The continents appear to fit together, especially Africa and South America.
Why did Wegener consider animal fossils to be evidence for the CDT?
When the fossils for the same specices of land animal that couldn’t swim or fly across oceans where found on sperate continents, Wegener took this tp mean that they would have had to have been connected together at some point in time.
Why did Wegener consider plant fossils to be evidence for the CDT?
The fossils of a plant that grew on land and produced large seeds (seedes that are unable to blow accros oceans) on sperate continentis, WEgener took this to mean that the continentis would have to have been connected together at one point in time.
How did rocks help provide evidence for the CDT?
Rocks of the same type/class and age were found on multiple continents.
How did the fossils of tropical plants help provide evidence for teh CDT?
Fossils of tropical plants were found in modern-day cold climate continents (Antartica and Siberia). Wegener took this to mean that teh continents may have been close to the equator at some point in time.
How did glacial evidence support the idea if the CDT?
Galical evidence was found on modern-day tropical continents (Africa, Austrila, India). This showed that these continents might have been close to the poles in the past.
Why were mountain ranges used as evidence for the CDT.
Similar mountain ranges were found on seperate continents. For example, mountain ranges in Brazil (S. America) match mountain ranges in Ghana (Africa).
What is the PTT?
PLate Tectonci Theory: the Earth is divided into plates that seperate, colide, rotate, or slide by each other. This creates geographic features in the ocean and on land.
Waht is a plate?
A chunk of crust that floats on top of the mantle.
CDT vs. PTT
The CDT states that only continents move. PTT states that thte enitre plate moves (which includes oceanic and continental crsut). The CDT has no good explination as to how continents move. PTT states that conversion clles in the matle make plates move aroud.
