Igneous Rock Practice Test

If necessary, review:

• Igneous Rocks Help
• Intrusive Igneous Rocks Help
• Extrusive Igneous Rocks Help
• Felsic and Mafic Rocks Help
• Crystallization Help
• Magnetism Help

Igneous Rock Practice Test

1. The deeper into the Earth you go, the

(a) dirtier you get

(b) smaller the distance to China

(c) hotter the temperature

(d) colder the temperature

2. Granite contains approximately how much silica?

(a) 30%

(b) 50%

(c) 70%

(d) 90%

3. The majority of rhyolites are made up of volcanic

(a) ash fragments

(b) glass with no obvious crystals

(c) sediments

(d) coal particles

4. Rock that contains high levels of magnesium and ferric (iron-containing) minerals are called

(a) mafic

(b) sofic

(c) felsic

(d) ionic

5. The last major magnetic reversal happened over

(a) 180,000 years ago

(b) 320,000 years ago

(c) 700,000 years ago

(d) 900,000 years ago

6. What percentage of the top 10 miles of the Earth’s crust is made up of igneous rock?

(a) 52%

(b) 75%

(c) 95%

(d) 99%

7. The cooled, crystallized magma that forces its way into surrounding rock is called

(a) extrusive igneous rock

(b) a bother, when it pops up in your corn field

(c) ash

(d) intrusive igneous rock

8. The South Atlantic Anomaly is

(a) a math error in your vacation savings account

(b) an island chain near Figi

(c) a weakened area of the Earth’s magnetic field

(d) a strongly magnetic area of the Earth’s magnetic field

9. Felsic rock has high levels of

(a) silicon in its composition

(b) felt in its composition

(c) boron in its composition

(d) tungsten in its composition

10. Extrusive igneous rock

(a) slowly works its way to the Earth’s surface

(b) is often blasted to the Earth’s surface

(c) can be found in tar pits

(d) always stays in the lithosphere

Answers:

1. C

2. C

3. B

4. A

5. C

6. C

7. D

8. C

9. A

10. B