1. The Rock Cycle
What is the rock cycle?

2. What exactly is a ROCK?
A rock is a naturally occurring solid. It is a mixture of one or more minerals & organic matter.
Rocks are always changing; this process of new rocks forming from old rocks is called the Rock Cycle

3. Are rocks useful?! Absolutely! What were they used for?
Uses of rocks: Hammers & other tools &…
knives
chert
arrowheads
obsidian

4. Rocks were not only used to make tools…
Rocks were also used to make buildings, monuments & roads.
Limestone, a sedimentary rock was used to make the pyramids
Washington Monument in D.C.-made of marble, granite & sandstone

5. What processes make & destroy rocks?
Geological processes such as erosion & deposition influence the type of rock that is formed on Earth’s surface

6. Sediment: small particles (usually dirt) that was suspended in water and has settled to the bottom of water.

7. Erosion is the process of removing sediment from its original location
Erosion is the process of removing sediment from its original location. Usually carried away by water or air; (it is displaced)

8. Deposition is the sediment that is carried away (or displaced) by erosion, is dropped off in a new location.

9. Feeling the Heat & Pressure
Sediment that is buried, can be squeezed by weight of layers on top of it to form sedimentary rock. When the pressure & temperature is high enough, the rock can change into metamorphic rock. If the rock gets hot enough inside the earth, the rock melts. The melted rock becomes magma; which then cools & forms igneous rock.

10. Compaction & cementation
Igneous Rock
cooling
melting
Weathering
Magma
Heat & pressure
sediment
melting
Weathering
Compaction & cementation
Metamorphic Rock
Weathering
Heat & pressure
Sedimentary Rock

12. Round & round the cycle goes
Buried rock is brought to the Earth’s surface by erosion & uplift (movement in the Earth, that brings rocks inside the Earth to the Earth’s surface). On the Earth’s surface weathering, erosion & deposition occur.

13. How are rocks classified?
All rocks can be classified into 3 main classes of rock based on how it is formed:
igneous, sedimentary & metamorphic
Each rock class can be divided further; also by how they form.
Ex: Igneous rock can form beneath Earth’s surface & other igneous rock can form above Earth’s surface

14. What is looked @ to classify rocks?
Composition:
the minerals that the rock contains
Texture:
the size, shape & grain position that make up the rock

15. Calcite

17. Rock Textures can Vary
Sedimentary rock can be: Medium grained Fine grained Coarse grained

18. Varying Rock Textures Continued…
Igneous Rock can be fine grained or coarse grained, depending on how much time the magma has to cool. Metamorphic rock can also be fine or coarse grained, depending on the amount of pressure & temperature the rock is exposed to.
Rock Type
Fine Grained
Medium Grained
Coarse Grained
Sedimentary X
Igneous
Metamorphic

19. Why do we care to look @ the texture anyway?!
For clues to tell us where & how the rock was formed
Basalt
Sandstone

20. Let’s see what we’ve learned!
Fill in the Blank:
The minerals that a rock is made of determine the __________ of that rock.
______ is a naturally occurring, solid mixture of crystals of one of more minerals.

21. Sediments are transported or moved from their original source by a process called:
a) deposition
b) erosion
c) uplift
d) weathering

22. Describe 2 ways that rocks have been used by humans
Describe 2 ways that rocks have been used by humans. Explain the difference between composition & texture

23. Look @ the table below to answer the question
Texture
Particle Size
Coarse grained
> 2mm
Medium grained
0.06 – 2 mm
Fine grained
<0.06 mm
Sandstone is a type of sedimentary rock. If you had a sample of sandstone that had an average particle size of 2 mm, what texture would your sandstone have?

24. Power Point Presentation made by Ms. Luck