 Lithosphere is broken into huge plates and float on the asthenosphere. How Plates Move

Divergent Boundary Plates move away from one another Magma, or molten rock from below Earth’s surface, oozes up, forming new crust When the pressure is great enough, the magma erupts as a volcano

Divergent Boundaries Found along the mid-ocean ridge a chain of mountains about 53,000 miles through all the world’s oceans Deep valleys (rifts), form where two plates move apart Magma is slowly pushed up through cracks in the rift to form new ocean floor and this process is called sea-floor spreading. As the new crust forms, it pushes the plates on the sides further apart.

Convergent Boundaries Plates move together and one plate moves down into the asthenosphere Plate melted by high temperature in asthenosphere When new crust forms at the divergent boundary then somewhere on Earth crust must be melting (at a convergent boundary)!!!! If it did not the Earth would continue to grow.

Visual Concept: Subduction Zone

Types of Convergent Collisions oceanic plate collides with another oceanic plate deep-ocean trench forms

Visual Concept: Convergent Boundary

Types of Convergent Boundaries two continental plates collide and one is forced beneath the other. plates crumple and fold forming mountain ranges

Visual Concept: Convergent Boundary

Types of Convergent Boundaries oceanic plate collides with continental plate oceanic plate forced downward Mountains and volcanoes form between the plates.

Visual Concept: Convergent Boundary

Transform Fault Boundaries Two plates move past one another No new crust formed No melting old crust Causes Earthquakes

Transform Fault Boundaries