Igneous Rocks

1
Igneous Rocks

• Chapters 3 4

Arcadia Natl Park, Maine
2

• How do Igneous Rocks form?
• 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?
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 rocks 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
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 magmas composition?

16

• What is Magma mixing how does it affect a
  magmas composition?

17
Who discovered Bowens Reaction Series?

• What is Bowens Reaction Series?

18
How are Igneous Rocks Classified?
19

• Felsic are _______ colored b/c theyre composed
  of orthoclase, Na-plagioclase, quartz.
• Rhyolite (A) Granite (B) most
  common intrusive rock

A
B
20

• Pegmatites are __________________ (grains gt1 cm
  in diameter) are mineralogically similar to
  ______.
• These mineral grains crystallized from
  ______________
• ____________________________________________.

21

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

B
A
22

• Mafic rocks are ______colored b/c theyre
  largely composed of ______________________________
  ________.
• Basalt (A) Gabbro (B)

A
B
23

• 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?

Pumice
Obsidian
25

• What are Tuffs?

26
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?