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)
Porphyritic (Rhyolite)
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. Laccolith – magma pushes overlying upward into an arch
Bear Butte, Black Hills, South Dakota

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

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

15. Formation of Sedimentary Rocks
Compaction
Cementation

16. Chemical Sedimentary Rocks
Halite (Rock Salt)
Evaporites precipitating from the hyper saline brine water in one of the playa lake, Thar desert
Gypsum Rock

17. Organic Sedimentary Rock
Chalk
Coal
Limestone with Fossils

18. Clastic Sedimentary Rock
Conglomerate (Round)
Breccia (Angular)
Sandstone (Sand-sized grains)
Shale (Clay-sized particles)

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

22. Formation of Metamorphic Rock
Contact Metamorphism

23. Formation of Metamorphic Rock
Regional Metamorphism

24. Types of Metamorphic Rock
FOLIATED ROCK
Slate: metamorphic shale
Gneiss: metamorphic granite

25. Types of Metamorphic Rock
NONFOLIATED ROCK
Quartzite: metamorphic quartz sandstone
Marble: metamorphic limestone