1. Daily Warm-Up Exercises
Day 4
What are the three major types of rock?
igneous, metamorphic & sedimentary
Based on the rock samples from the Compare Rock Types activity, what do most rocks appear to have in common?
Most rocks are made of minerals.
What are minerals?
inorganic (non-living), natural (not man-made), solid substances
Daily Warm-Up Exercises 1
Daily Warm-Up Exercises 1

2. Compare Rock Formation, Part 1
Contrasting Case Activity 2
Earth History, Investigation 8
In this activity, students will investigate the formation of igneous and metamorphic rocks. For each type, students will examine two rock samples and compare descriptions of how they were formed. This activity continues in contrasting case activity 3, which comes at the start of Investigation 4. In part 2, students will compare the formation of two sedimentary rocks, then use the comparison tables from both parts to investigate and depict the rock cycle.
Materials needed:
•rock samples 11 & 16; 1 & 20
•hand lenses
•igneous & metamorphic descriptions (worksheets 8 & 9)
•comparison tables (worksheets 11 & 12) STUDENTS WILL NEED THESE TABLES FOR CONTRASTING CASE ACTIVITY 3.
Compare Rock Formation
Compare Rock Formation

3. Do you remember… ...how igneous rocks form?
granite
An igneous rock forms when molten rock cools and hardens.
pumice
Igneous comes from the Latin word ignis, which means fire.
Students should recall these basic facts from the Compare Rock Types activity. Before showing the red box, ask:
What is molten rock?
melted rock
What do you think the word igneous means? Can you think of any words that are similar?
Similar words include ignite and ignition. Ignite means to light a fire. Ignition is the system provides the spark in an internal-combustion engine.
Tell your students that igneous rocks got their name because people used to think volcanoes were caused by fire inside the Earth.
Compare Rock Formation
Compare Rock Formation

4. Do you remember… ...how metamorphic rocks form?
schist
A metamorphic rock forms when an existing rock changes due to heat and/or pressure.
quartzite
Before revealing the purple box, ask:
What is pressure?
When something is squeezing or pushing on something else. The pressure on a rock beneath Earth's surface is caused by the weight of all the rocks above it.
What do you think the word metamorphic means?
Students may know about metamorphosis from learning about caterpillars changing into butterflies. Or they may have heard the word morph in connection with computer animations that change faces to other faces or science fiction characters that can change from one form to another.
Metamorphic means change in form.
Compare Rock Formation 4
Compare Rock Formation 4

5. Cross Section of Earth Inner Core: solid 4700°C to 4800°C
3 to 4 million times SP
Outer Core:
liquid
3450°C to 4700°C
1 to 3 million times SP
Mantle:
upper (outer) part = rigid solid
The purpose of this slide is to help students begin to appreciate the conditions of extreme heat and pressure that exist deep underground. The information will appear line-by-line on keypress, starting with the crust and moving toward the center of the Earth. At each level, ask your students to make predictions about state of matter, temperature, and pressure. For example, the surface of the crust includes oceans, and there are pockets of melted rock throughout the crust, but most of the crust is rigidly solid. Similarly, the temperature and pressure at the surface of the crust are the same as what we experience, but both increase with depth so that, at the bottom of the crust, the temperature can reach 1200ºC (which is about 2200ºF), and the pressure is 32,000 times what we experience at the surface.
The upper part of the mantle is rigidly solid like the crust. The lower part is a soft solid that flows very slowly. It's called a plastic solid, and it behaves a lot like Silly Putty.
Students don’t need to memorize the numbers, but they need to understand that there is heat and pressure inside the Earth, and they get more and more extreme the deeper you go.
lower part = soft (plastic) solid
1200°C to 3450°C
32,000 to 1 million times SP
Crust:
rigid solid
temperature can reach 1200°C
pressure is up to 32,000 times surface pressure (SP)
Compare Rock Formation 5

6. Which is Which? Look at rocks 11 & 16.
Igneous Rock 1 –
This rock is formed when molten rock cools and hardens. This process happens when magma pushes up into the crust but remains trapped underground. The temperature there is very warm, so the magma cools and hardens slowly. This slow cooling results in the formation of large crystals that are easily visible without a hand lens.
This rock makes up a large portion of Earth’s crust and mountain ranges. Because it forms deep underground, it is not visible until the earth above it erodes or is dug up. This rock is rough and dull, but it has crystals that look smooth and shiny. It is also very hard and long-lasting, so it is often used for headstones and other monuments.
Igneous Rock 2 –
This rock is formed when molten rock cools and hardens. This process happens when a volcano erupts and molten rock cools quickly on Earth's surface. In fact, it cools so quickly that no crystals form at all. Instead, it forms a glass.
This rock is smooth, shiny, and hard. Because it doesn’t have a crystal structure, it splits along smooth, curved edges. This feature makes it ideal for creating razor sharp tools. Such tools are often found during archeological digs, and some modern surgeons prefer blades made of this rock because they are sharper and thinner than steel. 11
– granite
Look at rocks 11 & 16.
Read & highlight WS 8 to figure out which rock goes with which description? 16
– obsidian
Do you remember what rock 11 is called?
Distribute the igneous case descriptions and rock samples 11 & 16. Before showing the questions, introduce two vocabulary words:
This activity is called Compare Rock Formation. What does FORMATION mean?
how something is made or comes to be
The second sentence contains the word process. What is a PROCESS?
a series of events or actions that produces an outcome; e.g., baking a cake, digestion, a basketball game
Have students work in groups, then share their answers with the class. The numbers will appear when you press the space bar.
Press the space bar again to reveal the second question. Students may recognize rock 11 as granite, since they examined that sample in the Compare Rocks activity. Tell them rock 16 is obsidian. Have students record the numbers and names on their case descriptions.
Compare Rock Formation

7. Compare Igneous Cases case 1 = granite (11) case 2 = obsidian (16)
Question
Same
Different
How does the rock form?
Granite –
Obsidian –
What features result from this process?
case 1 = granite (11)
Use this column for information that is true about both rocks.
Use this column for information that is true about one but not the other.
case 2 = obsidian (16)
Fill in the table by entering information from the paragraphs to answer each question.
Distribute the igneous comparison table.
Explain that part of the answer to a question may be the same for both rocks, and parts may be different. The part that is the same goes in the middle column. The parts that are different go in the column on the right.
The next slide shows the completed table for the two igneous rocks.
Compare Rock Formation
Compare Rock Formation

8. Igneous Rock Formation
Question
Same
Different
How does the rock form?
Granite –
Obsidian –
What features result from this process?
hardens slowly because the molten rock is trapped underground, where it is very warm
Molten rock cools and hardens.
hardens quickly when a volcano erupts and molten rock cools on Earth's surface
rough & dull, with large crystals that look smooth & shiny; very strong
The rock is hard.
Answers will appear individually on keypress. To help students understand how to fill in the answers, you might work through the questions as a whole class:
What's the same about how granite and obsidian form?
What's different about how granite forms?
What's different about how obsidian forms?
Do you see any features that are the same for both rocks?
Granite cools slowly. What features result from slow cooling?
Obsidian cools quickly. What features result from fast cooling?
no crystals; glass; smooth & shiny; splits along smooth, curved surfaces
Compare Rock Formation
Compare Rock Formation

9. Which is Which? Look at rocks 1 & 20.
Metamorphic Rock 1 –
This rock forms when shale, a sedimentary rock, changes due to heat and pressure. This process happens deep beneath Earth’s surface.
Before the change, shale is a smooth, hard, dull rock with very fine grains arranged in layers. After the change, the new rock is also smooth with very fine grains, but it is harder, shinier, and more compact than shale. Shale often contains fossils, but the new rock rarely does. The biggest change is that the new rock can be easily split into sheets of different thicknesses. For this reason, it is often used to make roofing tiles and paving stones.
Metamorphic Rock 2 –
This rock forms when slate, a metamorphic rock, changes due to extreme heat. This process happens deep beneath Earth’s surface.
Before the change, slate is smooth, fairly shiny, and hard. After the change, the new rock is rough and shiny, and small pieces tend to flake off easily. The biggest change is in grain size. Slate has very fine grains. The new rock has medium to coarse crystals that are flat and arranged in layers. Fossils are rarely found in slate or in the new rock. 20
– slate
Look at rocks 1 & 20.
Read & highlight WS 9 to figure out which rock is which? 1
– schist
Do you remember what rock 1 is called?
Distribute the metamorphic case descriptions and rock samples 1 & 20. Again, have students work in groups to figure out which is which, then share ideas with the class.
Students may recognize rock 1 as schist from the Compare Rocks activity. Tell them rock 20 is slate and have them record the numbers and names on their case descriptions.
Compare Rock Formation

10. Compare Metamorphic Cases
Question
Same
Different
How does the rock form?
Slate –
Schist –
What features result from this process?
case 1 = slate (20)
Use this column for information that is true about both rocks.
Use this column for information that is true about one but not the other.
case 2 = schist (1)
Fill in the table by entering information from the paragraphs to answer each question.
Distribute the metamorphic comparison table.
As students work, ask them to explain why metamorphic rocks rarely contain fossils. [fossils are usually destroyed by the heat and/or pressure that change the rocks]
The next slide shows the completed table for the two metamorphic rocks.
Compare Rock Formation
Compare Rock Formation

11. Metamorphic Rock Formation
Question
Same
Different
How does the rock form?
Slate –
Schist –
What features result from this process?
changes are caused by heat and pressure
An existing rock changes due to heat and/or pressure.
changes are caused by extreme heat
new rock is harder, shinier, and more compact; easily splits into sheets of different thicknesses
Fossils are usually destroyed.
Answers will appear individually on keypress.
very fine grains become medium to coarse crystals that are flat and arranged in layers
Compare Rock Formation
Compare Rock Formation

12. Compare Igneous & Metamorphic
Look at your igneous table. Based on these two rocks, how do igneous rocks form?
Igneous rocks form when molten rock cools and hardens. This process can happen slowly or quickly.
Look at your metamorphic table. Based on these two rocks, how do metamorphic rocks form?
(Formation of metamorphic rocks): The amount of heat and/or pressure can differ, so the changes can be extreme or not so extreme.
Metamorphic rocks form when an existing rock changes due to heat and/or pressure.
Compare Rock Formation
Compare Rock Formation

13. Compare Igneous & Metamorphic
What properties result from igneous formation?
Igneous rocks are usually hard. They usually have crystals, but obsidian does not have crystals.
What properties result from metamorphic formation?
Metamorphic rocks rarely have fossils because they are usually destroyed by the heat and/or pressure.
Emphasize that many of a rock’s properties depend on how it formed.
Compare Rock Formation
Compare Rock Formation