1. Warm-Up: Describe the texture and composition of each igneous rock.

2. Rocks Rock! Definition of A Rock
A naturally occurring, solid, mixture of one or more minerals or organic matter
Classified into 3 groups based on how they are formed: igneous, sedimentary, and metamorphic
Texture and composition give clues as to how rocks are formed, and are used to classify and identify rocks
Rocks are always changing form in a cycle called the Rock Cycle

3. Rock Classification
Composition – the type of minerals a rock contains (ex: Limestone is 95% Calcite and 5% Aragonite)
Texture – the size, shape and arrangement of the minerals that make up a rock. Can be fine, medium, or coarse.

4. The Rock Cycle
The main idea of the rock cycle is that rocks are continually changing from one type to another and back again
The elements that make up a rock are never created or destroyed - instead, they are constantly being recycled.

7. Igneous Rock Form when magma cools and hardens.
Sometimes look shiny and glasslike if lava cools quickly
Sometimes have tiny holes and spaces if gas is trapped in the rock as it cools
Two examples are: Basalt and Obsidian

8. Igneous Rocks Extrusive rocks- formed by cooling lava
Texture Can Be:
glassy
porous
fine-grained
Intrusive rocks- formed by cooling magma
Texture Is Always:
coarse-grained

9. Formation of Extrusive Igneous Rock

11. Igneous Features and Landforms
To view this animation, click “View” and then “Slide Show” on the top navigation bar.

12. Extrusive Igneous Rock

13. Formation of Intrusive Igneous Rock

14. Intrusive Igneous Rock
Yosemite N.P.

15. Examples of Textures: Pumice Obsidian Granite Basalt Porous Texture
Course Grained Texture
Basalt

16. Sedimentary Rock Formed from particles called sediments
Fairly soft and break easily
Contain sand, pebbles, stones, and is the only rock to contain fossils
Examples are: Conglomerate and Limestone
Form at or near Earth’s
surface
Most have layers or strata

17. Sedimentary Rocks Formed by: Weathering (breaking down of rock)
Erosion (movement of sediments)
Deposition (collection of sediments)
Compaction & Cementation (sediments bonding together)

18. Two Types of Weathering
1. Mechanical Weathering
Root Action
Frost Action
Moss

19. Types of Weathering 2. Chemical Weathering:
Oxidation (rust) – Oxygen in air reacts with metals in rocks
Acidic rain water

21. Physical Weathering
To view this animation, click “View” and then “Slide Show” on the top navigation bar.

22. Five Agents of Erosion Gravity (Mass wasting) Wind Running water
Glaciers
Waves

23. Gravity (Mass Wasting)
Soil creep
Slumping

25. Mass Movements: Five Main Types
To view this animation, click “View” and then “Slide Show” on the top navigation bar.

26. Wind

27. Running Water
Niagara Falls
Yellowstone Canyon & River

28. Glaciers

30. Glacial Processes I
To view this animation, click “View” and then “Slide Show” on the top navigation bar.

31. Waves
Australia

32. Examples of Deposition
Nile River Delta
Lateral moraine
Cape Cod (spit)

33. Compaction & Cementation

34. Sedimentary Rocks (categorized by composition)
Clastic Rocks (rock fragments)
Conglomerates (pebbles)
Sandstones (sand)
Shales (mud & clay)
Organic Rocks (once living)
Ex: limestone(coral and shells), coal (plants)
Chemical Rocks (evaporation)
Ex: rock salt, limestone, geodes, gypsum

35. Clastic Sedimentary Rock…
Conglomerate
Shale
Sandstone

36. Organic Sedimentary Rocks…
Coal (plant mateiral)
Limestone (shell & coral)

37. Chemical Sedimentary Rocks…
Gypsum rock
Limestone
Geode

38. Sedimentary rocks according to texture:
Fine-grained
Medium-grained
Shale
Sandstone
Coarse-grained
Conglomerate

39. Metamorphic Rock
Formed under the surface of the Earth due to extreme heat and pressure
Have ribbon-like layers and may have shiny crystals formed by minerals cooling slowly over time
Two examples are: Gneiss and Marble

40. Metamorphic Rocks
Formed by tremendous heat & pressure, and chemical reactions inside the crust.
Formed from all three rock types.

41. Formation of
Metamorphic Rock

42. Types of Metamorphic Rock
Slate
1. Foliated - bands or layers
Ex: schist, slate, gneiss
Gneiss

43. Types of Metamorphic Rock
2. Unfoliated - no bands or layers
Ex: marble and quartzite
Quartzite

44. Unfoliated Texture