1. < BackNext >PreviewMain The Rock Cycle Chapter 4 Key PointsNotes What is a rock? Composition Texture

2. < BackNext >PreviewMain A rock is a naturally occurring solid mixture of one or more minerals or organic matter. The Rock Cycle

3. < BackNext >PreviewMain Composition is the chemical makeup of a rock. Composition can describe either the minerals or other materials in the rock. The Rock Cycle

4. < BackNext >PreviewMain Texture based on the sizes, shapes, and positions of the rock’s grains (___________). MINERALS The Rock Cycle

5. < BackNext >PreviewMain Metamorphic Rock Formation Key PointsNotes How are metamorphic rocks formed?

6. < BackNext >PreviewMain As rocks undergo metamorphism, original minerals in a rock change into new minerals that are more stable within the new pressure and temperature conditions. Metamorphic Rock Formation

7. < BackNext >PreviewMain Metamorphic Rock Formation Key PointsNotes Where do metamorphic rocks form? Inside Earth’s crust (some closer to the surface, some much deeper)

8. < BackNext >PreviewMain Create one diagram to explain contact metamorphism and regional metamorphism

9. < BackNext >PreviewMain Index minerals are used to estimate the temperature, depth, and pressure at which a rock undergoes metamorphism in Earth’s crust. Metamorphic Rock Formation

10. < BackNext >PreviewMain Metamorphic Rock Formation Key PointsNotes Special identifying characteristics of metamorphic rocks Lines of stretched minerals Specific index minerals

11. < BackNext >PreviewMain Metamorphic Rock Formation Key PointsNotes 2 types of metamorphic rocks FOLIATED: Due to pressure, grains (minerals) have been stretched into bands NONFOLIATED: Grains (minerals) are randomly placed throughout rock

12. < BackNext >PreviewMain Identifying Characteristics (how do you know it’s metamorphic?) Foliated or Nonfoliated Name of Metamorphic Rock Detailed Illustration 1 2 3 4 5 Metamorphic Rock Identification

13. < BackNext >PreviewMain DO NOW 1)Open your textbook to the igneous rock section 2)Get out your rock cycle notes 3)Clear everything else off your desk

14. < BackNext >PreviewMain Igneous Rock Formation Key PointsNotes How are igneous rocks formed?

15. < BackNext >PreviewMain Igneous Rock Formation Igneous rock forms when hot, liquid rock, or magma, cools and solidifies. There are three ways magma can form: 1. When rock is heated 2. When pressure is released 3. When rock changes composition

16. < BackNext >PreviewMain Igneous Rock Formation Key PointsNotes Where do igneous rocks form? In a volcano or outside a volcano

17. < BackNext >PreviewMain Igneous Rock Formation Key PointsNotes What are the 2 types of igneous rock?

18. < BackNext >PreviewMain Igneous Rock Formation When magma intrudes, or pushes, into surrounding rock below the Earth’s surface and cools, the rock that forms is called intrusive igneous rock. Intrusive igneous rock has a coarse-grained texture because it is well insulated by surrounding rocks and cools very slowly.

19. < BackNext >PreviewMain Igneous Rock Formation Igneous rock that forms from magma that erupts, or extrudes, on the Earth’s surface is called extrusive igneous rock. Extrusive igneous rock, commonly found around volcanoes, cools quickly on the surface and contains very small crystals or no crystals.

20. < BackNext >PreviewMain Igneous Rock Formation

21. < BackNext >PreviewMain Igneous Rock Formation Sometimes, an igneous rock can be both fine and course-grained. These rocks are called porphyritic. How do you suppose porphyritic rocks are formed?

22. < BackNext >PreviewMain Igneous Rock Formation Key PointsNotes Special identifying characteristics of igneous rocks Found near a volcano Visible course-grained minerals that are not foliated (stretched) Found in a lava flow Very shiny (teeny-tiny fine- grained minerals) Vesicles Glassy Some tend to be lighter

23. < BackNext >PreviewMain Igneous Rock Formation Key PointsNotes 2 types of colors Light-colored FELSIC rocks are rich in elements such as aluminum, potassium, silicon, and sodium. Dark-colored MAFIC rocks are rich in calcium, iron, and magnesium.

24. < BackNext >PreviewMain Let’s Practice! Igneous Rock Formation What type of igneous rock is pictured? (composition, location) Mafic, Fine-grained, Extrusive

25. < BackNext >PreviewMain Let’s Practice! Igneous Rock Formation What type of igneous rock is pictured? (Composition, location) Felsic, Course-grained, Intrusive

26. < BackNext >PreviewMain Let’s Practice! Igneous Rock Formation What type of igneous rock is pictured? (Composition, location) Felsic, Fine-grained, Extrusive

27. < BackNext >PreviewMain Igneous Rock Identification Identifying Characteristics (how do you know it’s igneous?) Intrusive or Extrusive? Name of Igneous Rock Detailed Illustration 1 2 3 4 5