1. Earth Science
Chapter 4
Rocks!

2. What is the most interesting thing you learned during your research?
Bellwork
What is the most interesting thing you learned during your research?
Write it down and then we will talk about it!

3. Rocks are classified using 1. mineral composition 2. color 3. texture
Classifying Rocks
Rocks are classified using
1. mineral composition
2. color
3. texture

4. Rocks can be made of one, or a combination of several minerals
Mineral Content
Rocks can be made of one, or a combination of several minerals
There are about 20 main rock-building minerals

5. One mineral

6. Several minerals

7. Can help identify rocks Granite is usually light
Color
Can help identify rocks
Granite is usually light
Basalt is usually dark

8. Granite/Basalt

9. Texture
Texture
Grain size
Grain shape
Grain pattern

10. Fine-some only seen with microscope
Grain size
Fine-some only seen with microscope
Coarse-easily seen without microscope
No visible grain-none seen even with microscope

12. Grain pattern
Bands
Swirls
Colored bands
Random

13. Banded

14. Swirl

15. Colored bands

16. Random

17. What did you find most interesting about the crystal presentations?
Bellwork
What did you find most interesting about the crystal presentations?

18. Igneous: forms from the cooling of magma or lava
Igneous Formation
Igneous: forms from the cooling of magma or lava

19. Igneous formation

20. Sedimentary formation
Sedimentary rocks form when particles of other rocks or plant/animal remains are presses and cemented together

21. Sedimentary formation

22. Metamorphic formation
Metamorphic formation: forms when an existing rock is changed by heat, pressure, or chemical reactions.

23. Metamorphic formation

24. You do it! Read section 2 about igneous rocks.
Create a classification chart describing how igneous rocks are classified
Your chart should include information on origin, texture, and mineral composition of igneous rocks
Charts should also include illustrations, all vocabulary words, and examples of igneous rocks

25. Igneous Rock Classification
Origin
On or beneath Earth’s surface
Texture
Depends on the size and shape of mineral crystals
Mineral composition
Dependent upon the amount of silica in the lava or magma

26. Most common type is basalt Makes up most of the ocean’s floors
Origin
Extrusive Rock: igneous rock formed from lava that erupted onto Earth’s surface
Most common type is basalt
Makes up most of the ocean’s floors

27. Basalt

28. Most abundant intrusive rock is granite
Origin
Intrusive Rock: igneous rock that formed when magma hardened beneath the Earth’s surface
Most abundant intrusive rock is granite

30. Rapid cooling=small crystals, fine grain
Texture
Rapid cooling=small crystals, fine grain
Slow cooling=large crystals, coarse grain
Extrusive=smooth, fine grain
Intrusive=coarse, large grain

31. Texture
Extrusive
Intrusive

32. Mineral Composition
Lava is low in silica and dark colored
Magma is high in silica and generally light colored
Geologists look at rocks under a microscope to determine the mineral makeup

34. WHAT DID YOU FIND MOST INTERESTING ABOUT IGNEOUS ROCK FORMATION?
BELLWORK
WHAT DID YOU FIND MOST INTERESTING ABOUT IGNEOUS ROCK FORMATION?

35. SEDIMENTARY ROCKS READ SECTION 3 WITH A PARTNER
MAKE A FLOW CHART DESCRIBING THE FORMATION OF SEDIMENTARY ROCKS
YOUR CHART SHOULD INCLUDE:
DEFINITION OF SEDIMENT
4 STEPS OF THE PROCESS INCLUDING EXPLANATION
ILLUSTRATIONS

36. Sedimentary process
Erosion
Deposition
Compaction
Cementation

37. Natural forces break down and carry small pieces of rock
Erosion
Natural forces break down and carry small pieces of rock

38. Erosion

39. Deposition
The natural processes eventually drop the eroded rock/sediment and they form layers

41. This presses the visible layers of sediment together
Compaction
This presses the visible layers of sediment together

42. Cementation
During compaction, minerals dissolve in water, fill in gaps in the sediment, and act as a glue holding the newborn rock together

43. Cementation

44. CLASSIFY TYPES OF SEDIMENTARY ROCKS
MAKE A CLASSIFICATION CHART DESCRIBING THE THREE MAIN TYPES OF SEDIMENTARY ROCKS
CHARTS SHOULD INCLUDE DESCRIPTION OF ALL THREE TYPES
HOW THEY FORM
EXAMPLES
ILLUSTRATIONS

45. Classifying Sedimentary Rocks
Clastic
Organic
Chemical

46. Formed from rock fragments being squeezed together
Clastic
Formed from rock fragments being squeezed together
They can be small or large rock fragments
Clay/pebbles

47. Most common are shale, sandstone, conglomerate, and breccia
Clastic
Most common are shale, sandstone, conglomerate, and breccia
Most form from sand on beaches, ocean floor, riverbeds, and sand dunes

48. Shale

49. Sandstone