1. Ch 18 Review

2. Which of the following does NOT play a role in magma formation?
A) temperature
B) pressure
C) water
D) tephra

3. Which of the following is TRUE.
A) Increased pressure = higher melting point
B) Decreased pressure = higher melting point
C) Increased water = higher melting point
D) Increased pressure = lower melting point

4. Which of the following melts to form rhyolitic magma?
A) Continental crust
B) Oceanic crust
C) Oceanic sediment
D) The upper mantle

5. Which of the following melts to form andesitic magma?
A) Continental crust
B) Oceanic crust
C) Oceanic sediment
D) The upper mantle
B and C

6. Which of the following melts to form basaltic magma?
A) Continental crust
B) Oceanic crust
C) Oceanic sediment
D) The upper mantle

7. Which type of pluton is completely parallel to the surrounding rock layers?
A) dike
B) sill
C) laccolith
D) stock

8. The Hawaiian volcanoes formed as a result of which of the following?
A) divergence
B) A hot spot
C) subduction
D) convergence

9. Which of the following is NOT true?
A) More silica increases viscosity
B) Andesitic lava has intermediate gas content and explosiveness
C) Increased temperature increases viscosity
D) Basaltic magma has low viscosity and little gas.

10. Put these in order from smallest to largest:
Lapilli, dust, volcanic blocks, ash
dust, ash, lapilli, volcanic bock

11. Which of the following has a broad, gently sloping sides and a circular base?
A) Hot spot
B) Composite cone
C) cinder-cone volcano
D) Shield volcano

12. What type of volcano is each one?
Shield B
Composite C
Cinder cone

13. How is each made? Layer upon layer of relatively thin basaltic lava
Ejected volcanic material piles up
Volcanic fragments with alternating layers of lava

14. Which number is the…
Sill
Dike
Batholith
Laccolith
Volcano

15. What to STUDY for the test!
Chart on pg 474
Ch 18 Vocabulary
Ch 18 GRWs
Ch 18 Notes
Ch 18 Section Reviews
GOOD LUCK!