1. 3 Chapter 3

2. Rocks 3.1 The Rock Cycle  Rocks are any solid mass of mineral or mineral-like matter occurring naturally as a part of our planet.  Types of Rocks The 3 kinds of rocks are igneous, sedimentary, and metamorphic

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

4. The Rock Cycle

5. Igneous Rocks formed by the crystallization 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. Formation of Igneous Rocks 3.2 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 Rocks 3.2 Igneous Rocks 1. Texture  Igneous rocks can be classified based on their composition and 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.

8. Course-Grained Igneous Texture Granite

9. Fine-Grained Igneous Texture Rhyolite

10. Classification of Igneous Rocks 3.2 Igneous Rocks 1. Texture (continued) Glassy texture is caused by very rapid cooling. 2. Composition What minerals the rock is made of, based on the proportions of light and dark minerals in the rock.

11. Obsidian Exhibits a Glassy Texture.

12. Porphyritic Igneous Texture

13. Basalt

14. Classification of Igneous Rocks

15. Formation of Sedimentary Rocks 3.3 Sedimentary Rocks Erosion involves the weathering and the removal of rock. Deposition occurs when an agent of erosion—water, wind, ice, or gravity—loses energy and drops sediments. Sedimentary Rocks

16. Sedimentary Rock Formation

17. 3.3 Sedimentary Rocks Compaction is a process that squeezes, or compacts, sediments. Cementation takes place when dissolved minerals are deposited in the tiny spaces among the sediments.

18. 3 Types of Sedimentary Rock Clastic – composed of weathered bits of rocks and minerals –Classified by particle size –Ex: Shale, Sandstone, Conglomerate, Grand canyon & the wave in Arizona

19. Shale with Plant Fossils

20. Sandstone

21. Conglomerate

22. The Wave, Page, AZ

23. Grand Canyon, Arizona

26. 3 Types of Sedimentary Rock Chemical – When minerals dissolve out of water –Ex: limestone (caves), coal, rock salt

27. Fossiliferous Limestone

28. Carlsbad Caverns, NM Stalactites Stalagmites

29. 3 Types of Sedimentary Rock Organic – Formed by fossils or organic matter within the rock layers

30. Classification of Sedimentary Rocks

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

32. Agents of Metamorphism 3.4 Metamorphic Rocks  Heat  Pressure Provides the energy needed to drive chemical reactions Causes a more compact rock with greater density

33. Origin of Pressure in Metamorphism

34. Agents of Metamorphism 3.4 Metamorphic Rocks Hot water-based solutions escaping from magma Dissolves original minerals and then deposits new ones  Hydrothermal Solutions

35. Classification of Metamorphic Rocks 3.4 Metamorphic Rocks 1. Foliated Metamorphic Rock 2. Nonfoliated Metamorphic Rock  Two main categories Has a banded or layered appearance Does not have a banded texture

36. Classification of Metamorphic Rocks

37. Gneiss Typically Displays a Banded Appearance

38. Marble — A Nonfoliated Metamorphic Rock