Question

1. the age of oceanic crust a. gets older as we move away from an oceanic ridge b. gets younger as we move away from an oceanic ridge c. is always older than the continental crust d. stays the same from oceanic ridge to trench 10. ridge - push is associated with which type of plate boundary? a. convergent b. divergent c. transform d. all of the above 11. all major interactions between plates occur a. on the underside of each plate b. near the center of each plate c. along plate margins d. none of these 12. movement of tectonic plates is caused by... a. the lunar tides b. convection currents in the outer core c. pressure in the earths core d. convection currents in the mantle 13. a collision between two pieces of continental crust produces a... a. mid - ocean ridge b. rift valley c. deep - ocean trench d. mountain range 14. which of the following evidence supports sea - floor spreading? a. magnetic stripes form identical patterns on both sides of the ocean ridge. b. older rocks are found closer to subduction zones. c. volcanic islands have shifted away from hot spots. d. all of the above 15. older ocean floor is being destroyed along which type of boundary? a. divergent b. convergent c. transform d. fault 16. when two oceanic plates converge... a. a mid - ocean ridge is formed. b. the denser of the two sinks back down into the mantle. c. the less dense of the two sinks back down into the mantle. d. a mountain range is formed. 17. the point beneath the earths surface where a mass of rock breaks under stress and triggers an earthquake is called the a. syncline b. footwall c. epicenter d. focus

Explanation:

1. Ocean - floor rocks get older as we move away from an oceanic ridge due to sea - floor spreading.
2. Ridge - push is associated with divergent plate boundaries where new crust is formed.
3. Major plate interactions occur along plate margins.
4. Tectonic plate movement is caused by convection currents in the mantle.
5. A collision between two continental crusts forms a mountain range.
6. Magnetic stripes, older rocks near subduction zones, and volcanic island movement support sea - floor spreading.
7. Older ocean floor is destroyed at convergent boundaries.
8. When two oceanic plates converge, the denser one sinks into the mantle.
9. The point beneath the Earth's surface where rock breaks and triggers an earthquake is the focus.

Answer:

1. a. gets older as we move away from an oceanic ridge
2. b. divergent
3. c. along plate margins
4. d. convection currents in the mantle
5. d. mountain range
6. d. All of the above
7. b. convergent
8. c. The denser of the two sinks back down into the mantle.
9. d. focus