Plate tectonics Flashcards
What is plate techtonic theory?
In 1960, it changed the way geologist look at the world. it explains how large landforms were made. like mountains, volcanoes and earthquakes.
What is Gondwana?
It was the name of the super continent. because they found similar plants and fossils across india, australia, south america, and antarctica.
What is pangea?
A theory developed by Alfred Wegener. Meaning all land, so one giant land mass of all of the continents.
What is Laurasia?
A northern continental mass, north america, greenland, europe and asia.
What was evidence used to support continental drift?
The fit of all of the continents.
Rock type and structural similarities
Fossil evidence
Paleoclimatic/glacial evidence
What are fossils used for evidence of continental drift?
Glassopteris, Cynognathus, Mesosaurus, Lystrosaurus
What was the downfall of the theory of continental drift?
Lack of mechanism.
What are the two discoveries that were made that support continental drift?
Paleomagnetism, Sea floor spreading.
Explain how the earth is a giant magnet?
It is similar to a bar magnet with south and a north end.
What confirmed the theory of sea floor spreading?
Deep sea drilling, they could see that the crust was newest near the ridges and older the further you go out.
What drives the movement of the plates?
Convection currents
what are the 12 large plates?
North american
south american
african
pacific
eurasian
australian- indian
antarctic
What is a divergent plate boundary?
located along the crust of oceanic ridges, sea floor spreading and are constructive plate margins.
What is an oceanic-oceanic convergent plate boundary?
forms an ocean trench and volcanic islands
what is a oceanic-continental convergent boundary?
A complex subduction zone, forms a trench and volcanoes
