1. Igneous Rocks
Chapters 3 & 4
Arcadia Nat’l Park, Maine

2. How do Igneous Rocks form? How are plutons & volcanoes related?
What is Magma?
What is Lava?
How do they form?
What are the two categories of igneous rocks?
How does each type form?
How are plutons & volcanoes related?

3. How Hot Is Lava?
How long does it take lava to cool?

4. Where Does Magma Originate?
Where are Magma Chamber located?

5. What is the Geothermal gradient?
How does pressure affect the melting point of a rock?

6. How does water affect rocks at depth?

7. TEXTURES of Igneous Rocks
What is Texture?
What does a rock’s grain size indicate?
What is Aphanitic texture and what does it indicate?

8. TEXTURES of Igneous Rocks (cont.)
What is Glassy texture & what does it indicate?
What is Vesicular texture & what does it indicate? a b

9. TEXTURES of Igneous Rocks (cont.)
What is Phaneritic texture & what does it indicate?

10. TEXTURES of Igneous Rocks (cont.)
What is Porphyritic texture & what does it indicate?

11. TEXTURES of Igneous Rocks (cont.)
What is Pyroclastic (fragmental) texture & what does it indicate?

12. What is the most abundant constituent of magma?
Magma Composition
What is the most abundant constituent of magma?
What characteristics do Felsic magmas have?
What characteristics do Intermediate magmas have?
What characteristics do Mafic magmas have?
What characteristics do Ultramafic magmas have?

13. Composition of Igneous Rocks
What controls the type of rock that forms?
What are the 4 Magma Modification Processes?

14. What is Crystal settling?

15. What is Assimilation?
How does it affect a magma’s composition?

16. What is Magma mixing & how does it affect a magma’s composition?

17. Who discovered Bowen’s Reaction Series?
What is Bowen’s Reaction Series?

18. How are Igneous Rocks Classified?

19. Rhyolite (A) Granite (B) [most common intrusive rock]
Felsic are _______ colored b/c they’re composed of orthoclase, Na-plagioclase, & quartz.
Rhyolite (A) Granite (B) [most common intrusive rock] A B

20. Pegmatites are __________________ (grains >1 cm in diameter) & are mineralogically similar to ______.
These mineral grains crystallized from ______________
____________________________________________.

21. Andesite (A) Diorite (B) [erupts from island arcs]
Intermediate contain _________ amts of _________ colored ferromagnesian silicates, & _________ colored feldspar.
Andesite (A) Diorite (B)
[erupts from island arcs] A B

22. Mafic rocks are ______colored b/c they’re largely composed of ______________________________________.
Basalt (A) Gabbro (B) A B

23. Ultramafic are _____ colored b/c they are comp
Ultramafic are _____ colored b/c they are comp. of ________________________________ silicates.
What are Peridotites composed of olivine?
Where are Peridotites formed?

24. What is Volcanic Glass composed of?
What rock type has a similar composition?
Why can volcanic glass be different colors?
What are vesicles & how are they formed?
Obsidian
Pumice

25. What are Tuffs?

26. What are the Magma Types at Convergent Margins?
How do magmas move?
What is Magma type at Divergent Margins & Hot Spots?
What are the Magma Types at Convergent Margins?
How are these magmas
formed?