Igneous Rocks Homework

Arizona Geology Chapter 6 Homework Igneous Rocks

DUE – Wednesday February 18.

READ CHAPTER 1 ROCKS AND MINERALS AND 6 IGNEOUS ROCKS in Geology of Arizona (STOP AT METAMORPHIC ROCKS)

Answer these questions in complete sentences in your COMPOSITION BOOK.

Remember to answer in complete sentences for full credit. 4 points each. 60 pts

1. What is magma like?
2. What is viscosity? What factor affects a magma’s viscosity?
3. Why does magma rise to the surface? What are two things that can happen to magma as it rises to the surface?
4. What evidence is there that the temperature is very hot below the earth’s surface?
5. Explain the geothermal gradient.
6. Were is magma generated in the crust? What evidence of this?
7. How does pressure affect the melting temperature of rock?
8. What happens when heat is added to crystals in magma ? What is this process called?
9. What is a magma chamber? How does one form?
10. Why are igneous rocks classified as plutonic and volcanic?
11. What are the 2 parameters that igneous rocks are classified?
12. How does the rate of cooling affect the crystal size of igneous rock?
13. What does a porphyritic texture indicate about an igneous rock?
14. Make a chart – one whole page - 8 elements account for most of the Earth’s crust? (again?!)
15. What does the color of an igneous rock indicate?