Plate tectonics/continental drift flashcards
What is the plate tectonic theory?
A theory that states that Earth’s plates move, causing mountain buildings, volcanoes, earthquakes, etc.
Where are you most effected by a tsunami or Earthquake?
On the edge of a tectonic plate
How is Oceanic crust described as?
Thin, made of basalt, dense, dark, low silica.
How is Continental crust described as?
Thick, made of granite, less dense, light, high slica.
What are the three types of plate boundaries?
Transform, divergent, and convergent
what are transform plate boundaries?
plates that slide past each other, causes earthquakes
what are divergent plate boundaries?
plates that’s spread apart, causes volcanism, MOR, some earthquakes
Who theorized that hot, molten material forced its way out of MOR and when did he do it?
Harry Hess, early 60’s
What is seafloor spreading?
A process in which tectonic plates split apart from each other
What are the two evidences that seafloor spreading happens?
Lava pillows and magnetic stripes
What are lava pillows?
Spherical lobes of lava
What are magnetic stripes?
Iron materials in molten lava align to Earth’s magnetic field
What does MOR stand for?
Mid-Ocean Ridge
What is the continental drift hypothesis?
Something that suggests that continents are is constant movement
What is Pangea?
A large made of land, that was once made of all the continents
