1. Crustal Features 8.9B relate plate tectonics to the formation of crustal features

2. What is Earth’s crust? Earth’s crust covers the mantle. The crust is the outermost layer surface layer. – 25 miles thick under continents – 6.5 miles thick under oceans

4. What makes up the crust? Oceanic crust – Rocks that make up the oceanic crust are relatively young compared to the rocks that make up the continental crust. It is mostly basalt rock. Continental crust – Continental crust is older than oceanic crust. It has two layers, mostly igneous rock. The upper crust is mostly granite. The lower crust is mostly basalt and diorite.

5. Moving crust The crust is part of the lithosphere, the outermost layer of the crust. Plates are part of the crust. (continental crust/plate and oceanic crust/plate) The convection currents in the mantle layer below and perhaps also gravity cause the plates to move.

6. What happens when plates move? When the plates move, the surface of the crusts change. Earthquakes, volcanoes, ocean ridges, and mountains are all crustal features that form when plates move.

7. How do plates move?

8. When two boundaries converge (come together), volcanoes and mountain building is common.

9. When two boundaries diverge (move away) from one another, this is common in oceans to form rifts.

10. When two boundaries transform (slide past) one another, earthquakes are common.

11. Crustal plate boundaries is where you would expect to find the most activity.

12. Look at where most earthquakes occur, along plate boundaries.

13. Look at where most volcanoes are found, also along boundaries.