1. Rock Compostion

2. Rock – a naturally occurring solid mixture of one or more minerals or organic matter

3. Rocks are ALWAYS changing
Rock cycle – the continual process by which new rock forms from old rock material

4. Early Uses of Rock
Hammers
Arrowheads
Spear points
Knives
Scrapers

5. Types of Rock include:
Granite
Limestone
Marble
Sandstone
Slate

6. Name some types of rock that have been used to construct buildings.

7. Certain geological processes make and destroy rock.
The processes shape the features of our planet.
These processes also influence the type of rock that is found in a certain area of Earth’s surface.

8. Weathering – the process in which water, wind, ice and heat break down rock

9. Weathering Breaks down rock into fragments
Helps to create sedimentary rock

10. Erosion – the process by which sediment is removed from its source

11. Deposition – the process in which material is laid down

12. Turn to page 91 and read “Processes That Shape the Earth” in your textbook.
Study the five steps listed that illustrate the rock cycle on page 92.

13. Igneous rock can change into sedimentary rock; metamorphic rock, or even back into igneous rock.
As one rock type is changed to another type, several variables, including time, heat, pressure, weathering, and erosion may alter a rock’s identity.
The location of the rock determines which natural forces will have the biggest impact on the process of change.

14. Scientists divide rock into three categories: igneous, sedimentary, and metamorphic.
However, based on how and where the rock forms, further divisions can be made.
Scientists study a rock’s composition and texture to classify it.

15. Composition – the chemical makeup of a rock; describes the minerals found in the rock

16. Texture – the quality of a rock that is based on the sizes, shapes, and positions of the rock’s grains

17. Igneous Rock

18. Igneous rock forms when hot, liquid rock, or magma, cools and solidifies.

19. 3 ways Magma can form: When rock is heated When pressure is released
When rock changes composition

20. Magma freezes between 700*C and 1,250*C.

21. The longer it takes for magma to cool, the more time crystals have to grow.
The more time crystals have to grow, the larger the crystals are and the coarser the texture of the rock is.
The less time it takes to cool, the less crystals will grow, resulting in a smoother rock.

22. Igneous rock, or magma, can form above or below the surface of Earth.
What do we call an igneous rock formation that is above the surface of Earth?

23. Sedimentary Rock

24. Sedimentary rock forms at or near Earth’s surface.
It forms without the heat and pressure that are involved in the formation of igneous and metamorphic rock.

25. Ways sedimentary rock form:
Wind
Water
Ice
Sunlight
Gravity

26. Strata – layers of rock; the most noticeable feature of sedimentary rock.

27. Types of organic sedimentary rock:
Fossils
Coral
Shells from sealife
Coal

28. Metamorphic Rock

29. Metamorphic rocks are rocks in which the structure, texture, or composition of the rock have changed.
All three types of rock can be changed by heat, pressure, or a combination of both.

30. Causes for Metamorphism
Heat by nearby magma
Built up pressure in Earth
Collision of Earth’s crust
Analogy examples: baking cookies or frying an egg
What analogy can you think of?

31. Deformation – a change in the shape of a rock caused by a force placed on it.
These forces may cause a rock to be squeezed or stretched.