The actual quiz will consist of 20 - 25 questions to be answered in 30 minutes at the end of class.  The questions will be short answer, fill in the blank, label the diagram, or draw a diagram.  The quiz will be worth 50 points.  We will have an informal review on Thursday (1 February) in room 142 (1060) Physical Sciences starting at 6:30 PM.  It should last about one hour.

Key Terms

Amphibole	Andesite
Aphanitic	Basalt
Batholith	Bowen reaction series
Bowen's Reaction Series	Ca-rich plagioclase
Cinder cone	Columnar jointing
Concordant	Continuous Reaction Series
Continuous series	Country Rock
Cross-cutting Relationships	Dike
Diorite	Discontinuous Reaction Series
Discontinuous series	Discordant
Extrusive	Felsic
Gabbro	Granite
Groundmass	Intermediate
Intrusive	Komatiite
K-rich plagioclase	Laccolith
Lahar	Lava dome
Lava plateau	Law of Superposition
Mafic	Matrix
Mica	Na-rich plagioclase
Olivine	Pegmatite
Peridotite	Phaneritic
Phenocryst	Porphyritic
Pyroclastic	Pyroxene
Quartz	Rhyolite
Shield	Silicic
Sill	Stock
Stratocone	Ultramafic
Viscosity	Xenolith

Practice questions/concepts:

1. Why would silicic lava be more likely to be explosive?
2. Describe how a porphyritic rock might form.
3. Explain how Bowen's Reaction Series also relates to how minerals will weather.
4. Know the relationships between [Si], [Mg], [Fe], viscosity, overall composition, explosiveness, and eruptive temperature.
5. What are the small bubbles found in some extrusive igneous rocks called?
6. What is the volcanic rock that has the composition of granite?
7. What are the two most abundant igneous rocks?
8. How does the presence of volatiles, such as water, affect grain-size?
9. How does the chemical composition of magma affect its viscosity?
10. What type of pyroclastic rock commonly floats?
11. Would a gabbro be composed of olivine and quartz?  Why or why not?
12. How might a piece of sedimentary rock be found within an extrusive igneous rock?
13. Understand the difference between a sill and a dike and relative ages based on fundamental geologic principles.
14. What are rocks that are taken from the surrounding material and incorporated into magma as coherent pieces are called?
15. What is an outcrop of intrusive igneous rock called if it has an area greater than 100 mi2?
16. What is an outcrop of intrusive igneous rock called if it has an area less than 100 mi2?
17. What is generally the largest type of volcano?
18. Which type of volcano is the most explosive?  Why?
19. Why is the statement "volcanoes erupt because of gravity" correct?
20. Describe how you would tell an active, dormant, and inactive volcano apart.
21. Describe how a composite volcano would form.