Earth’s Plates

1. Plate Boundaries: Where different plates meet Forces are great enough to cause: mountains to form rift valleys faults Earth’s Plates

2. Plates that move apart: result of pulling force called tension occurs under oceans at mid-ocean ridges new crust forms to fill in the gap new crust is less dense as new crust moves away from the ridge it cools and becomes more dense Earth’s Plates

3. Plates that collide: continental-continental collisions continental-oceanic collisions oceanic-oceanic collisions Earth’s Plates

4. Continental-continental collisions: continental plates have similar densities buckle and fold when collide piling up high mountain ranges Himalayas and Appalachians Earth’s Plates

5. Continental-oceanic collisions: more dense oceanic plate subducts below the continental into the mantle volcanoes form Mount St. Helens Earth’s Plates

6. Oceanic-oceanic collisions: more dense oceanic plate subducts below the other, into the mantle volcanoes islands form Many of the Caribbean Islands Earth’s Plates

7. Plates that slide past each other: faults form earthquakes occur San Andreas Fault, CA Earth’s Plates