1. Daily Warm-Up Exercises
Day 2
When someone says a rock has fine grains or coarse grains, what are they talking about?
Grains are the particles that make up a rock. The words fine and coarse refer to the size of the grains. Fine grains are small, and coarse grains are larger.
What is molten rock?
What are particles?
pieces; fragments; bits
Molten rock is melted rock.
Daily Warm-Up Exercises 1
Compare Rock Types, Part 2
Daily Warm-Up Exercises 1

2. Introduction to the Grand Canyon Earth History, Investigation 8
Trilobite Hunter, Part 2
Introduction to the Grand Canyon
Earth History, Investigation 8
The first two slides return to the Trilobite Hunter scenario and introduce the second Grand Canyon video. After seeing the video, students continue the first cc activity, Compare Rock Types.
Materials needed:
•Grand Canyon Video, parts 2 & 3
•rock samples 1 & 18; 7 & 8
•hand lenses
•metamorphic & sedimentary cards (worksheets 2 & 3)
•Venn diagrams (worksheets 5 & 6)
Compare Rock Types, Part 2

3. Return to Trilobite Hunter
Are igneous rocks good for finding trilobite fossils?
granite
pumice
No, because they are made of molten rock, which is much too hot to preserve organisms. 3
Compare Rock Types, Part 2 3

4. Return to Trilobite Hunter
We are now going to look at a second type of rock, called metamorphic. We’ll find out if metamorphic rocks are good for finding fossils.
These rocks are found in some of the deepest layers of the Grand Canyon.
At this time, show Grand Canyon Video, part 2. When the video is finished, proceed to the next slide to continue the contrasting case activity. 4
Compare Rock Types, Part 2 4

5. Contrasting Case Activity 1, Part 2 Earth History, Investigation 8
Compare Rock Types
Contrasting Case Activity 1, Part 2
Earth History, Investigation 8
In today’s activity, students will examine two metamorphic rocks and complete a Venn diagram to show how they compare. They will then do the same thing with two sedimentary rocks. On Day 3, they’ll use all three Venn diagrams to compare the three rock types.
Compare Rock Types 5
Compare Rock Types, Part 2 5

6. List Observable Features
Metamorphic #1
Metamorphic #18
List the features you can observe about the two metamorphic rock samples.
Distribute rock samples 1 & 18. Again, have students work in pairs or groups, then share their observations with the class.
Compare Rock Types 6
Compare Rock Types, Part 2 6

7. Which is Which? 1
Can you figure out which rock is schist and which is quartzite? 18
Distribute the metamorphic rock description cards and have students compare their lists with the cards. Questions and numbers will appear on keypress.
To see the layering described on the card, students may need to turn the rock and look at its side. Like a stack of pancakes, you can’t see the layers if you look down at the top. You have to view them from a certain angle.
When you hear the word PRESSURE, interrupt the class to ask what it means. You might give an example: When someone is bleeding, you’re supposed to put pressure on the wound. What does that mean? [press down, push down, squeeze] So pressure is when something is squeezing or pushing on something else. Tell your students that the pressure on a rock beneath Earth's surface is caused by the weight of all the rocks above it.
Compare Rock Types 7
Compare Rock Types, Part 2 7

8. What’s the Same? What’s Different?1 18
Identify similarities and differences and write them in the Venn diagram.
Again, have students work in groups, then share their answers with the class. Each student should record all the similarities they can find, but they only need to record one difference for each sample. The next slide starts with a blank diagram. Press a key to fill in the center section. Repeat for the left and then the right sections.
Compare Rock Types 8
Compare Rock Types, Part 2 8

9. Both Schist & Quartzite
Metamorphic
Schist Only
Both Schist & Quartzite
Quartzite Only
Fairly shiny
Rough
Dull and hard
Medium to coarse grain size
Made of minerals
Fine grain size
Formed when a rock changes due to heat and/or pressure
Crystals are flat and arranged in layers
Grains appear to be fused together
Formed from slate, a metamorphic rock
Both rocks feel rough, both are made of minerals, both are formed when a rock changes due to heat and/or pressure, and both are formed deep beneath Earth’s surface.
Again, emphasize that, because they are based on just two samples of each rock type, TODAY’S CONCLUSIONS ARE ALL VERY TENTATIVE. For example, schist can form from rocks other than slate, such as basalt and limestone.
Formed deep beneath Earth’s surface
Formed from sandstone, a sedimentary rock
Compare Rock Types 9
Compare Rock Types, Part 2 9

10. Return to Trilobite Hunter
Are metamorphic rocks good for finding trilobite fossils? Explain.
schist
quartzite
Not very good because the heat and/or pressure will usually destroy any fossils contained in the original rock. 10
Compare Rock Types, Part 2 10

11. Return to Trilobite Hunter
At this time, show Grand Canyon Video, part 3. When the video is finished, proceed to the next slide to continue the contrasting case activity.
Let’s look at one more type of rock, sedimentary. We’ll find out if sedimentary rocks are good for finding trilobite fossils. Now let’s watch the video clips from Trilobite Hunter! 11
Compare Rock Types, Part 2 11

12. List Observable Features
Sedimentary #7
Sedimentary #8
List the features you can observe about the two sedimentary rock samples.
Distribute rock samples 7 & 8 and have students work in groups, then share ideas with the class.
Compare Rock Types 12
Compare Rock Types, Part 2 12

13. Which is Which? 7
Can you figure out which rock is shale and which is sandstone? 8
Distribute the sedimentary rock description cards (shale & sandstone). As students work, listen for opportunities to discuss vocabulary:
What are FOSSILS?
remnants or traces of plants or animals that have been embedded or preserved in a rock
What is SILT?
a substance that is a lot like sand, but has much finer grains
What is CLAY?
similar to silt, but with even finer grains
What is COMPACTED?
squeezed or pressed together so it takes up less space
What is CEMENTED?
glued or stuck together
Compare Rock Types 13
Compare Rock Types, Part 2 13

14. What’s the Same? What’s Different?7 8
Identify similarities and differences and write them in the Venn diagram.
Again, have students identify all similarities and at least one difference and list them in the diagram. The next slide starts with a blank diagram. Press the space bar to fill each section.
Compare Rock Types 14
Compare Rock Types, Part 2 14

15. Sedimentary Shale Only Both Shale & Sandstone Sandstone Only Smooth
Dull and hard
Rough
Very fine grain size
May contain fossils
Medium to coarse grain size
Made of minerals
Grains are arranged in layers
Formed when something gets compacted and cemented together
Formed from grains of sand
Formed from particles of silt or clay
Both rocks are dull and hard. Both may contain fossils. Both are made of minerals. Both are formed when something gets compacted and cemented together, and both may form on or below Earth’s surface.
May form on or below Earth’s surface
Compare Rock Types 15
Compare Rock Types, Part 2 15