*6th Grade Topic 8 Lessons 1 - 4

an undersea mountain chain where new ocean floor is produced; a divergent plate boundary under the ocean

• mid-ocean ridge

• sea floor spreading

• subduction

• ocean trench

an undersea valley that represents one of the deepest parts of the ocean

• mid-ocean ridge

• sea floor spreading

• subduction

• ocean trench

the process by which molten materials adds new oceanic crust to the ocean floor

• mid-ocean ridge

• sea floor spreading

• subduction

• ocean trench

the process by which oceanic crust sinks beneath a deep ocean trench and back into the mantle at a convergent plate boundary

• mid-ocean ridge

• sea floor spreading

• subduction

• ocean trench

a plate boundary where two plates move toward each other

• divergent boundary

• convergent boundary

• transform boundary

• transition boundary

a plate boundary where two plates move away from each other

• divergent boundary

• convergent boundary

• transform boundary

• transition boundary

a plate boundary where two plates move past each other in opposite directions.

• divergent boundary

• convergent boundary

• transform boundary

• transition boundary

stress that squeazes rock until it folds or breaks

• stress

• tension

• compression

• shearing

stress that pushes masses of rock in opposite directions, in a sideways movement

• stress

• tension

• compression

• shearing

a force that acts on rock to change its shape or volume

• stress

• tension

• compression

• shearing