1. Chapter 3
Rocks

2. 3.1 The Rock Cycle
Rocks
 Rocks are any solid mass of mineral or mineral-like matter occurring naturally as a part of our planet.
 Types of Rocks
Igneous
Sedimentary
Metamorphic

3. The Rock Cycle
Interactions between water, air, land, and living things can cause rocks to change from one type to another

4. Weathering and Erosion
Weathering  is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters.
Erosion is the movement, transportation, and deposition of soil and rock by wind, water, and gravity to other locations.

5. Igneous Rocks
formed by the crystallization (hardening) of molten magma or lava.
Magma is molten material deep beneath the Earth’s surface
Lava is molten material above the surface
Igneous
Rocks

6. 3.2 Igneous Rocks Formation of Igneous Rocks
1. Intrusive igneous rocks are formed when magma hardens beneath Earth’s surface.
2. Extrusive igneous rocks are formed when lava hardens (above the Earth’s surface).

7. Classification of Igneous Rock
Texture
Coarse-grained texture is caused by slow cooling resulting in larger crystals.
Fine-grained texture is caused by rapid cooling resulting in smaller, interconnected mineral grains.
Glassy texture is caused by very rapid cooling.
Composition
What minerals the rock is made of, based on the proportions of light and dark minerals in the rock.

8. Granite
Rhyolite
Obsidian
Basalt

9. Classification of Igneous Rocks

10. 3.3 Sedimentary Rocks What are Sedimentary Rocks? Sedimentary Rocks
• Rocks made from pieces of other rocks

11. 3 Types of Sedimentary Rock
Clastic – composed of weathered bits of rocks and minerals
Classified by particle size
Ex: Shale, Sandstone, Conglomerate

12. The Wave, Page, AZ

13. Grand Canyon, Arizona

14. 3 Types of Sedimentary Rock
Chemical – When minerals dissolve out of water
Ex: limestone (caves), rock salt
Carlsbad Caverns, NM
Stalactites
Stalagmites

15. 3 Types of Sedimentary Rock
Organic – Formed by fossils or organic matter within the rock layers
coal

16. Classification of Sedimentary Rocks

17. 3.4 Metamorphic Rocks Formation of Metamorphic Rocks
 Metamorphism means “to change form.”
 Igneous and sedimentary rocks change at increased temperatures and pressures deep within the Earth or during mountain building
Metamorphic
Rocks

18. 3.4 Metamorphic Rocks Agents of Metamorphism  Heat  Pressure
Provides the energy needed to drive chemical reactions
 Pressure
Causes a more compact rock with greater density
 Hydrothermal Solutions
Hot water-based solutions escaping from magma
Dissolves original minerals and then deposits new ones

19. Origin of Pressure in Metamorphism

20. 3.4 Metamorphic Rocks Classification of Metamorphic Rocks
 Two main categories
1. Foliated Metamorphic Rock
Has a banded or layered appearance
If the pressure applied to the rock is unequal, then a foliated rock will form.
2. Nonfoliated Metamorphic Rock
Does not have a banded texture
Gneiss
Marble

21. Classification of Metamorphic Rocks