T1- Plate Tectonics Flashcards
Plate tectonics
A theory stating that the earth’s surface is broken into plates that move
Crust
The thin and solid outermost layer of the Earth above the mantle
Mantle
The largest layer of the earth between the crust and the core which is made up of semi-molten rock which is constantly moved by convection currents.
Outer core
A layer of molten iron and nickel that surrounds the inner core of Earth
Inner core
A dense sphere of solid iron and nickel at the center of Earth
Convection current
A circular current of molten magma in the mantle caused due to the difference in temperatures within the mantle.
Magma
Molten rock beneath the earth’s surface
Lava
Magma that reaches Earth’s surface
Constructive plate margin
A plate margin where two plates are moving apart
Destructive plate margin
A plate margin where two plates are moving towards each other resulting in one denser plate sinking beneath the other.
Collision plate margin
Two continental plates collide. Neither plate is forced under the other, and so both are forced up and form fold mountains
Conservative plate margin
Tectonic plate margin where two tectonic plates slide past each other
Continental crust
The relatively thick but less dense part of the earth’s crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.
Image: Continental Crust
Oceanic crust
Thinner, more dense, younger crust making ocean floor
Subduction zone
In tectonic plates, the site at which an oceanic plate is sliding under a continental plate.
