Chapter 10 Section 3By: Kat Kenney, Jeff Hicks, and Carissa

Blanco

Plate tectonics is the theory that Earth’s crust and upper mantle are broken into plates

that float and move around on a plastic like layer of the mantle.

Plate Tectonics

Plates are sections of Earth’s crust and upper mantle.

Plate

The lithosphere is the rigid layer of Earth that is about 100 km thick. It is made of the crust and a part of the upper mantle.

Lithosphere

The asthenosphere is the plastic like layer of Earth on which the lithospheric plates float

and move around.

Asthenosphere

A convection current is a current in earth’s mantle that transfers heat in Earth's interior and is the driving force for plate tectonics.It is also known as the cycle of heating,

rising, and cooling.

Convection Current

When continental plates pull apart, they can form rift valleys.

Rift Valley

Where oceanic and continental plates collide, the oceanic plate plunges beneath the less

dense continental plate. As the plate descends, molten rock forms and rises

towards the surface, forming volcanoes.

Subduction

Hess’s theory that new seafloor is formed when magma is forced upward toward the

surface at a mid-ocean ridge.

Seafloor Spreading

Where two continental plates collide, they push up the crust to form mountain ranges

such as the Himalaya.

Continental Collision

One type of plate boundary is a convergent boundary, where plates move together.

Another type of plate boundary is a divergent boundary, where plates pull

apart. Finally, there is a transform boundary where plates slide past each other.

Plate Boundaries

A volcano can form at a subduction zone. When the oceanic plate plunges beneath

the continental plate, it melts. The magma rises into the continental plate and forms

volcanoes.

Volcanoes