1. The Rock Cycle

2. Section 3.2 Vocabulary to know: Igneous rock Magma Lava
Extrusive igneous rock
Intrusive igneous rock
Texture
Composition
Silicate

3. What are igneous rocks? Igneous rock-
Form from molten rock deep within the Earth that has cooled… OR…
From molten rock that has reached the surface and cooled lava
Temperatures deep within the Earth are hot enough (14000F to 23000F) to melt rock

4. Where do igneous rocks come from?
Volcanoes!
Extrusive igneous rock-
Forms when lava cools on Earth’s surface
Intrusive igneous rock-
Forms when magma cools within the Earth

5. Textures of igneous rocks
Texture = size of the rock’s mineral crystals
Large crystals- slow cooling time
Intrusive rocks commonly have large crystals
Small/No crystals- fast cooling time
Extrusive rocks commonly have small or no crystals

6. How can you tell the difference between salt and sugar?

7. Answer = look at their composition!
Igneous rocks are mainly made up of silicate minerals

8. Ship Rock Formed 1km below Earth’s surface
It was once intrusive igneous rock
It is what’s left behind of magma that once fed a volcano
Through weathering and erosion, surface rock has been worn away…
…Ship Rock survives because igneous rock is usually harder than other types of rocks

9. Section 3.3 Vocabulary to know: Sedimentary rock Sediment Cementation
Coal
Limestone
Crossbeds
Ripples

10. What are sedimentary rocks?
Forms from loose material (sediments) that get pressed together (cemented) into rock
Sediments-
Can be pieces of rocks, minerals, plants, or animals

11. Sedimentary rock formation…
Rainwater washes away rock particles…
Flow downhill to streams and rivers…
Eventually these sediments reach the ocean…
Settle on the bottom of the ocean…
Pressure eventually forces these sediments together…
Sedimentary rock is formed!

12. Fossils can also make sedimentary rock
Coal-
Made up of remains of plants (dead wood, bark, leaves, etc.)
Started forming millions of years ago
Limestone-
Made up of remains of ocean organisms (shells, bones, etc.)
Pressure “squishes” these materials together into rock

13. Coal formation
A- Dead pieces of plant matter collecting on lake bottom
B- sediments applying pressure on top of plant matter
C- Even greater pressure applied
D- Coal is created

14. Limestone towers (Mono Lake)
Minerals can dissolve in water …
…and then re-form as the water evaporates
Often they form underwater…
…and as the water level drops they become visible

15. Sedimentary rocks can teach us about the past…
Crossbeds-
These layers were once moving sand dunes
Ripples-
The surface of this sandstone preserves ancient sand ripples

16. Section 3.4 Vocabulary to know: Metamorphic rock Metamorphism
Recrystallization
Foliation
Foliated rock
Nonfoliated rock

17. What are metamorphic rocks?
Forms when heat or pressure cause older rocks to change into new types of rocks
Metamorphism-
The process in which existing rock is changed by heat or pressure

18. Metamorphic rock formation
During metamorphism rocks undergo many changes
Heat and pressure can break the bonds that join the atoms in minerals… the atoms then join together differently
Recrystallization
Rocks do not melt during this process!!!

19. Foliation Foliation- Foliated rocks- Nonfoliated rocks-
An arrangement of minerals in flat or wavy parallel bands
Foliated rocks-
Develop under pressure
Minerals flatten out or line up in bands
Nonfoliated rocks-
Develop if rock is made up of only one type of mineral
May not be under enough pressure

20. The Rock Cycle