1. IGNEOUS ROCKS
“Hot Stuff”

2. Igneous Sedimentary Metamorphic

3. Igneous Rocks: (def) rocks that are formed from the crystallization of magma or lava.

4. Magma: molten rock beneath the earth’s surface Lava: molten rock on the earth’s surface

5. I. Location of igneous rocks
Compose 95% of earth’s crust.

6. II. Texture and Cooling Rates
A. Texture (?):

7. II. Texture and Cooling Rates
A. Texture (?): refers to the SIZE of the individual minerals.

8. II. Texture and Cooling Rates
Texture (?): refers to the SIZE of the individual minerals.
Cooling rates:
Inside vs. on the surface

10. II. Texture and Cooling Rates
Texture (?): refers to the SIZE of the individual minerals.
Cooling rates:
Inside vs. on the surface
C. Extrusive (Volcanic) Rocks: cool rapidly at the surface.

11. II. Texture and Cooling Rates
Texture (?): refers to the SIZE of the individual minerals.
Cooling rates:
Inside vs. on the surface
C. Extrusive (Volcanic) Rocks: cool rapidly at the surface.
D. Intrusive (Plutonic) Rocks: cool slowly inside the earth.

12. III. Types of Textures

13. III. Types of Textures
Phaneritic
“coarse-grained”

14. III. Types of Textures Phaneritic “coarse-grained” B. Aphanitic
“fine grained”

15. III. Types of Textures Phaneritic “coarse-grained” B. Aphanitic
“fine grained”
AT WHAT RATE DID THEY COOL?

16. III. Types of Textures Phaneritic “coarse-grained” B. Aphanitic
“fine grained”
C. Porphyritic
“coarse and fine”
Phenocrysts and matrix

17. III. Types of Textures C. Porphyritic “coarse and fine” Matrix
Phenocrysts

18. III. Types of Textures
D. Others (pyroclastic,
glassy, cellular)

19. IV. Composition
A. “New” Magma

20. IV. Composition “New” Magma
* most originate as basaltic in composition

21. IV. Composition “New” Magma * most originate as basaltic
* rich in elements Fe, Ca, Mg

22. IV. Composition “New” Magma * most originate as basaltic
* rich in elements Fe, Ca, Mg
* as magma cooling occurs, minerals containing these elements are formed.

23. IV. Composition “New” Magma * most originate as basaltic
* rich in elements Fe, Ca, Mg
* as magma cooling occurs, minerals containing these elements are formed.
* remaining magma is granitic, rich in elements Si, Al, K

24. IV. Composition “New” Magma * most originate as basaltic
* rich in elements Fe, Ca, Mg
* as magma cooling occurs, minerals containing these elements are formed.
* remaining magma is granitic, rich in elements Si, Al, K
* Temperatures:
--Basalt Magmas: HOT C
--Granitic Magmas: (COOLER) 800 C

25. IV. Composition B. Process of Crystallization N. L. Bowen (1937)
“Bowen’s Reaction Series”

27. Olivine
Ca Plag. Feldspar

28. Ca-Na Feldspar
Pyroxene
Ca Plag. Feldspar
Olivine

29. Na-Ca Feldspar
Amphibole
Ca-Na Feldspar
Pyroxene
Ca Plag. Feldspar
Olivine

30. Biotite
Na Plag. Feldspar
Amphibole
Na-Ca Feldspar
Ca-Na Feldspar
Pyroxene
Ca Plag. Feldspar
Olivine

31. Orthoclase Feldspar
Biotite
Na Plag. Feldspar
Amphibole
Na-Ca Feldspar
Ca-Na Feldspar
Pyroxene
Ca Plag. Feldspar
Olivine

32. Muscovite
Orthoclase Feldspar
Biotite
Na Plag. Feldspar
Amphibole
Na-Ca Feldspar
Ca-Na Feldspar
Pyroxene
Ca Plag. Feldspar
Olivine

33. Quartz
Muscovite
Orthoclase Feldspar
Biotite
Na Plag. Feldspar
Amphibole
Na-Ca Feldspar
Ca-Na Feldspar
Pyroxene
Ca Plag. Feldspar
Olivine

34. High Temp
(1300 C)
Low Temp
(600 C)

35. High Temp
(1300 C)
Olivine
Low Temp
(600 C)

36. High Temp
(1300 C)
Olivine
Ca Plagioclase
Feldspar
Low Temp
(600 C)

37. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Low Temp
(600 C)

38. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Low Temp
(600 C)

39. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Low Temp
(600 C)

40. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
Low Temp
(600 C)

41. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
Muscovite
Low Temp
(600 C)

42. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
Muscovite
Low Temp
(600 C)
Quartz

43. Ca Plagioclase Feldspar DARK Pyroxene Ca-Na Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
DARK
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
Muscovite
Low Temp
(600 C)
Quartz

44. Ca Plagioclase Feldspar DARK Pyroxene Ca-Na Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
DARK
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
LIGHT
Muscovite
Low Temp
(600 C)
Quartz

45. Ca Plagioclase Feldspar DARK Pyroxene Ca-Na Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
DARK
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
INTERM
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
LIGHT
Muscovite
Low Temp
(600 C)
Quartz

49. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
LIGHT
Muscovite
Low Temp
(600 C)
Quartz

52. Ca Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
LIGHT
Muscovite
Low Temp
(600 C)
Quartz

56. Ca Plagioclase Feldspar DARK Pyroxene Ca-Na Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
DARK
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
Muscovite
Low Temp
(600 C)
Quartz

59. Ca Plagioclase Feldspar DARK Pyroxene Ca-Na Plagioclase Feldspar
High Temp
(1300 C)
Olivine
Ca Plagioclase Feldspar
DARK
Pyroxene
Ca-Na Plagioclase Feldspar
Amphibole
Na-Ca Plagioclase Feldspar
Biotite
Na Plagioclase Feldspar
Orthoclase Feldspar
Muscovite
Low Temp
(600 C)
Quartz

68. PUMICE
OBSIDIAN
OBSIDIAN

70. SCORIA

72. PERIDOTITE

73. Igneous “Thought” Questions
What minerals would you expect to find in a basalt?
If a granite cooled quickly, what rock would form?
What rocks are chemically the same as diorite?
Why are the minerals olivine and quartz usually not found together in the same rock?

74. V. Classification of Igneous Bodies

75. V. Classification of Igneous Bodies
Pluton (def): any igneous body that is placed underneath the earth’s surface.

76. V. Classification of Igneous Bodies
Pluton (def): any igneous body that is placed underneath the earth’s surface
B. Terms:
Concordant vs.Discordant

77. V. Classification of Igneous Bodies
Pluton (def): any igneous body that is placed underneath the earth’s surface
B. Terms:
Concordant vs.Discordant
Tabular, Massive, Lenticular

79. DISCORDANT

80. CONCORDANT
DISCORDANT

81. MASSIVE!!!

82. TABULAR

83. LENTICULAR

84. V. Classification of Igneous Bodies
C. Classification
1. Batholiths and Stocks

85. V. Classification of Igneous Bodies
C. Classification
1. Batholiths and Stocks
YOSEMITE, CA
MOUNT RUSHMORE, SD

86. STOCKS
SHIP ROCK, NM

87. V. Classification of Igneous Bodies
C. Classification
2. Dikes

88. DIKE

89. BASALT DIKE, SHENANDOAH NATL. PARK

92. V. Classification of Igneous Bodies
C. Classification
3. Sills

93. SILL

94. V. Classification of Igneous Bodies
C. Classification
4. Laccoliths

99. 3-D VIEW
BIRD’S EYE VIEW

101. YIKES!!!!

103. VI. OTHER TOPICS
A. Xenoliths

107. VI. OTHER TOPICS
Xenoliths
B. Pegmatites