1. Rocks and the Rock Cycle
Chapter 6

2. The Rock Cycle
What types of rocks were the first type on the Earth?

3. IGNEOUS

4. Bowen’s Reaction Series
Canadian Geologist, Norman L. Bowen, recognized that certain minerals tend to crystallize first. As they crystallize, they remove specific elements, changing the composition of magma as it cools.

5. Partial Melting vs. Fractional Crystallization

6. Classification of Igneous Rocks
Intrusive Igneous Rocks
Slow cooling below surface
Visible crystals
Extrusive Igneous Rocks
Fast cooling at surface
No crystals or very very small crystals

7. Textures of Igneous Rocks
Fine-grained (Rhyolite)
Coarse-grained (Granite)
Vesicular (pumice)
Glassy (obsidian)

8. Composition of Igneous Rocks
FELSIC
MAFIC

9. Types of Lava Mafic Felsic Color Dark Light Composition Magnesium/iron
Silica, Aluminum
Origin
Ocean crust
Cont. crust
Temp
Hot
Cool
Viscosity
Thin
Thick
Eruption Type
Quiet
Violent
Example
Hawaii
Mt. St. Helens

10. Intrusive Igneous Rock Features

11. Batholith – large mass (100 square km) of igneous rock
Stock – smaller version of a batholith
Oregon Batholith after surrounding
rock has been eroded away

12. Half Dome, Yosemite National Park

13. Stone Mountain. GA

14. Laccolith – magma pushes overlying upward into an arch
Bear Butte, Black Hills, South Dakota

15. Sill – magma flows between layers of rock - horizontal

16. Dike – igneous formation that cuts across rock layers - vertical
A five-mile-long volcanic wall, a dike, radiating from Shiprock in distance

17. Formation of Sedimentary Rocks
Compaction
Cementation

18. Chemical Sedimentary Rocks
Form by precipitation of minerals from water when dissolved materials come out of water.
Halite (Rock Salt)
Halite and Gypsum
Evaporites precipitating from the hyper saline brine water in one of the playa lake, Thar desert
Gypsum Rock

19. Gypsum

20. Gypsum Uses
Plaster and Wallboard
Other Uses of Gypsum

21. Halite (Rock Salt)

22. Organic Sedimentary Rock
Formed from the remains
of plants or animals
Coal
Chalk
Coquina – limestone with fossil shells
Limestone with Fossils

23. Clastic Sedimentary Rock
Conglomerate (Round)
Shale (Clay-sized particles)
Sandstone (Sand-sized grains)
Form when fragments of rocks are compacted and cemented together

24. Sedimentary Rock Features
Cross-beds
Stratification in the Grand Canyon
Mud Ripples

27. Metamorphic Rock
Contact Metamorphism - Due to contact with an igneous intrusion.

28. Metamorphic Rock
Regional Metamorphism – occurs over a large area like a plate boundary

29. Types of Metamorphic Rock
Foliated = layered or banded
Slate: metamorphic shale
Gneiss: metamorphic granite
Schist – garnet and muscovite

30. Granite >>>>>Schist

31. Types of Metamorphic Rock
Non-Foliated – No layers
Quartzite: metamorphic quartz sandstone
Marble: metamorphic limestone