Download Rocks and How They Form

Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
Science Grade 06 Unit 09 Exemplar Lesson 02: Rocks and How They Form
This lesson is one approach to teaching the State Standards associated with this unit. Districts are encouraged to customize this lesson by
supplementing with district-approved resources, materials, and activities to best meet the needs of learners. The duration for this lesson is only a
recommendation, and districts may modify the time frame to meet students’ needs. To better understand how your district may be implementing
CSCOPE lessons, please contact your child’s teacher. (For your convenience, please find linked the TEA Commissioner’s List of State Board of
Education Approved Instructional Resources and Midcycle State Adopted Instructional Materials.)
Lesson Synopsis
Students will classify igneous, sedimentary, and metamorphic rocks based on the processes of their formation. They will develop an understanding of
the multiple pathways of the rock cycle.
TEKS
The Texas Essential Knowledge and Skills (TEKS) listed below are the standards adopted by the State Board of Education, which are required by
Texas law. Any standard that has a strike-through (e.g. sample phrase) indicates that portion of the standard is taught in a previous or subsequent
unit. The TEKS are available on the Texas Education Agency website at http://www.tea.state.tx.us/index2.aspx?id=6148.
6.10
Earth and space. The student understands the structure of Earth, the rock cycle, and plate tectonics. The student is
expected to:
6.10B Classify rocks as metamorphic, igneous, or sedimentary by the processes of their formation.
Scientific Process TEKS
6.2
Scientific investigation and reasoning. The student uses scientific inquiry methods during laboratory and field
investigations. The student is expected to:
6.2E Analyze data to formulate reasonable explanations, communicate valid conclusions supported by the data, and predict trends.
6.4
Scientific investigation and reasoning. The student knows how to use a variety of tools and safety equipment to
conduct science inquiry. The student is expected to:
6.4A Use appropriate tools to collect, record, and analyze information, including journals/notebooks, beakers, Petri dishes, meter sticks, graduated
cylinders, hot plates, test tubes, triple beam balances, microscopes, thermometers, calculators, computers, timing devices, and other
equipment as needed to teach the curriculum.
GETTING READY FOR INSTRUCTION
Performance Indicators
Grade 06 Science Unit 09 PI 02
Create a museum exhibit on rocks. In the exhibit, classify samples of rocks as metamorphic, igneous, or sedimentary by the processes of their formation.
Standard(s): 6.2E , 6.10B
ELPS ELPS.c.1C , ELPS.c.5C
Key Understandings
Rocks are classified by the process through which they are formed.
— How are sedimentary rocks formed?
— How are rocks weathered?
— How are rocks eroded?
— How are rocks deposited?
— How are metamorphic rocks formed?
— How are igneous rocks formed?
— Why are igneous rocks classified into subcategories of intrusive and extrusive?
— What is the rock cycle?
Vocabulary of Instruction
cementation
compaction
sedimentation
sediment
weathering
erosion
deposition
minerals
rocks
crystals
metamorphic rock
igneous rock
sedimentary rock
rock cycle
Last Updated 05/23/13
page 1 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
Materials
aluminum foil (1 roll, per teacher demonstration)
aluminum pan (1 per group, for Station B)
beakers (50 mL, 2 for Station 2)
beakers (small, between 10–50 mL, 2 for Station 3)
chalk (sidewalk - not dustless, 2 small equal-size pieces per group rotation, for Station 2)
clay (modeling, small amount, per group, for Station A)
clothes pin (1, wooden, spring-type per group)
drinking straw (flexible neck,1 per student)
glue or tape (per group)
graduated cylinders (10 mL, 2 for Station 2)
gravel (small handful per group, for Station 1)
hand lens (1 per student)
hole punch (hand held, 1 per teacher for Station A)
hot plate (1 per group)
ice (various per group rotation)
ketchup (10 mL per group rotation, for Station 3)
lemon juice (10 mL per group rotation, for Station 3)
materials to create displays (colored paper, egg carton sections, cardstock, blocks, foam packing, etc., various per class)
paper (blank, 1 sheet per student)
pennies (dull, 3 per group rotation, for Station 3)
petri dish (1 per group)
pipettes (2 per group, for Station B)
plastic container (disposable, clear with lid, 1 for Station A)
plastic container small, clear, with lid, 1 per group, for Station 1)
plate (small, plastic or foam per group)
reference books about rocks (various per class)
rocks (samples of igneous, sedimentary, and metamorphic, 1 per student)
safety goggles (1 pair per student)
safety goggles (1 per teacher)
sand (small amount, for Station A)
scissors (1 pair per student)
scissors (1 per teacher demonstration)
soil (small amount, per group rotation, for Station B)
Starburst™ candies (3–4 different colors per group)
sugar cubes
tape or glue (per group)
timing device
vinegar (20 mL per group rotation, for Station 2)
water (tap)
wax crayons (different colors, per teacher demonstration)
Attachments
All attachments associated with this lesson are referenced in the body of the lesson. Due to considerations for grading or student assessment,
attachments that are connected with Performance Indicators or serve as answer keys are available in the district site and are not accessible on the
public website.
Teacher Resource: Who Are We? (see Advance Preparation, 1 set per group)
Teacher Resource: Lab Station 1- Mechanical Weathering (see Advance Preparation, 1 for station)
Teacher Resource: Lab Station 2- Chemical Weathering (see Advance Preparation, 1 for station)
Teacher Resource: Lab Station 3- Chemical Weathering (see Advance Preparation, 1 for station)
Teacher Resource: PowerPoint: The Process of Weathering Rocks
Handout: Weathering Notes
Teacher Resource: Weathering Notes KEY
Teacher Resource: Lab Station A- Wind Erosion (see Advance Preparation, 1 for station)
Teacher Resource: Lab Station B- Water Erosion (see Advance Preparation, 1 for station)
Handout: Erosion and Deposition Notes (1 per student)
Teacher Resource: Erosion and Deposition Notes KEY
Teacher Resource: PowerPoint: The Process of Erosion and Deposition of Sediments
Last Updated 05/23/13
page 2 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
Teacher Resource: The Process of Forming Sedimentary Rock (1 class set)
Teacher Resource: PowerPoint: Sedimentary Rocks
Teacher Resource: Sugar Cube Rocks (1 per group)
Teacher Resource: The Process of Forming Igneous Rock (1 class set)
Teacher Resource: PowerPoint: Igneous Rocks
Teacher Resource: The Process of Forming Metamorphic Rock (1 class set)
Teacher Resource: PowerPoint: Metamorphic Rocks
Teacher Resource: Rock Cycle Guide KEY (1 for projection)
Handout: Rock Cycle Guide (1 per student)
Handout: Rock Cycle Practice (1 per student)
Teacher Resource: Rock Cycle Practice KEY
Teacher Resource: Performance Indicator Instructions KEY (1 for projection)
Resources
None Identified
Advance Preparation
1. Locate, assemble, and prepare all materials.
2. Prior to Day 1:
Print on cardstock, laminate, cut a part, and bag the Handout: Who Are We? You will need one set per group.
Print on cardstock and laminate the following: Teacher Resource: Lab Station 1- Mechanical Weathering (1 per station), Teacher Resource:
Lab Station 2- Chemical Weathering (1 per station), and Teacher Resource: Lab Station 3- Chemical Weathering (1 per station)
Weathering Station 1 – Use a clear, plastic jar with a lid such as a peanut butter or small mayonnaise jar. You will need a container to
place the gravel in. When all groups have finished with the station for the lesson, the gravel should be rinsed of sugar granules. Allow the
gravel to dry so that it can be reused.
Weathering Station 2 – The beaker size should be large enough so that the chalk pieces are submerged. Sidewalk chalk works well.
Dustless chalk contains clay and will not give the same effect. Vinegar is a weak acid and will dissolve the chalk which is made from the
exoskeletons of microscopic sea organisms. Vinegar and water can be drained, and the chalk can be thrown in the trash receptacle.
Weathering Station 3 – Again, the size of the beakers should be small enough so that 10 mL of the acidic substance will cover the penny.
Use old pennies that are dull, brown or, otherwise, discolored. Two replacement pennies will have to be used for each rotation of the
station. Arrange an area for the shiny pennies to be placed.
3. Prior to Day 3:
Print on cardstock and laminate the following: Teacher Resource: Lab Station A- Wind Erosion (1 per station) and Teacher Resource: Lab
Station B- Water Erosion (1 per station).
Erosion and Deposition Station A – Use a hand held hole punch to make a hole in the side end of a plastic container about half way up the
container. It may be necessary to place two holes overlapping to get a hole large enough to place a straw through. A container with softer sides
is preferable, such as sandwich meat containers. A second alternative is for the teacher to poke holes by holding a nail with pliers and heating
it. Push the hot nail through the container.
Erosion and Deposition Station B – The amount of soil doesn’t have to be large. Straws may be used instead of pipettes. Place a straw in the
water, and place a finger over the top. To release water, remove the finger covering the end. You will need one container for disposal of the
water and one for the soil. The soil may be dried out and reused.
4. Prior to Day 7, gather samples of three types of rocks and label the type of rock they are.
5. Prior to Day 8:
Gather enough samples of a variety of all rock types for all of your students to have one rock - only labeled with its name.
Arrange for student computer/Internet use.
Gather reference books about types of rocks.
6. Prepare attachment(s) as necessary.
Background Information
This lesson covers the classification of types of rocks and processes that form rocks within the rock cycle.
During this lesson, students will develop an understanding that the Earth is comprised of mostly rock and learn to classify rocks by the processes that formed those rocks.
They should develop the understanding that rocks bear evidence of the minerals, temperatures, and forces that created them. After this unit, students in Grade 6 will use
these concepts in the next unit dealing with plate tectonics. These concepts are not directly taught again in Grade 8.
INSTRUCTIONAL PROCEDURES
Last Updated 05/23/13
page 3 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
Instructional Procedures
ENGAGE – Who Are We?
Notes for Teacher
NOTE: 1 Day = 50 minutes
Suggested Day 1
1. Divide the class into groups of four.
Attachments:
2. Distribute card sets from the Teacher Resource: Who Are We? (see Advance
Preparation) to each group. Instruct students to look at the photos and labels and
read the clue cards.
3. Instruct students to discuss the information and match the clue cards to the correct
photo cards and labels.
4. Students may or may not be able to match correctly. Monitor and guide groups as
necessary. The lesson will address the characteristics of the three classifications of
rocks in more detail.
5. The master will serve as a Key as well as the information below. The rocks in each
photo are:
Igneous – granite, obsidian, and scoria
Metamorphic – slate and marble
Sedimentary – conglomerate, sandstone, and limestone
Minerals – feldspar and quartz
Teacher Resource: Who Are We? (see Advance
Preparation, 1 set per group)
Instructional Notes:
Making explicit connections to previous units of study makes for a
great review and formatively assesses retention of previously
studied concepts.
NOTE: Students are not expected to recognize the types of rocks by
visual observation.
Allow students access to classroom resources such as reference
books or textbooks that may contain needed information.
Science Notebooks:
6. Ask:
What are the three main types of rock? (Igneous, sedimentary, and
metamorphic)
What is a rock? Answers will vary; a naturally-formed solid made of one or more
minerals
What is the difference between a rock and mineral? Answers will vary.
Students should recall the information from the previous Unit 02 Lesson 02:
Physical Properties of Minerals. Acknowledge all answers without correction. Post
student answers on the board.
Students record terms and descriptions in their notebooks.
Throughout the lesson, students continue to record underlined
terms and their descriptions in their notebooks.
7. Instruct students to write the terms mineral and rock in their science notebooks.
Using the posted answers from above, work with students to develop a definition for
each term. Use the information below to guide students to their class definitions.
Students should then add their definitions to their notebooks.
A mineral is a solid, inorganic substance with a definite chemical composition.
They have a crystal structure which means they have a specific orderly
arrangement of atoms.
Minerals can be made of one or more elements.
Minerals are formed by the cooling of magma and evaporation of water containing
dissolved mineral, and they can change into different minerals with heat,
pressure, or chemical reactions.
Minerals compose rocks.
A rock is a naturally-formed solid made of one or more minerals.
All rocks on or below the Earth’s surface belong to one of three groups: igneous,
formed when molten rock cools; sedimentary, formed when small pieces of
weathered material settle in layers and are cemented together; and metamorphic,
formed from other rocks by heat and pressure.
8. Ask:
If rocks are made of minerals, what are minerals made of? (Elements) Make
a connection back to the study of elements.
If elements make minerals and minerals make rocks, what layer of the
earth do rocks make up? (The crust) Make a connection to elements in the
Earth’s crust (Si, O).
9. Collect the card sets for future use.
EXPLORE/EXPLAIN – Weathering
Suggested Days 1 (continued) and 2
1. Divide the class into groups of 4–5 for station rotations. Set up duplicate stations to
maintain small group sizes.
Materials:
2. Review safety and clean up procedures for each station, prior to beginning stations.
(see Advance Preparation)
Last Updated 05/23/13
page 4 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
You may wish to review each station’s procedures, or you may allow students to read
the directions at each station.
3. Instruct students to bring their notebooks to each station. They are to include the
following in the notebooks for each station:
Complete title and number of the station
Any data tables on the station card
Any drawings/labeling requested on the station card
4. Rotate students through the three stations at your signal. Students should leave the
station in the condition in which they found it at the beginning of the rotation. Give
them a one minute warning before signaling movement to the next station.
5. Monitor groups, and assist as needed.
6. The general results of each station:
plastic container small, clear, with lid, 1 per group,
for Station 1)
gravel (small handful per group, for Station 1)
sugar cubes (5 per group rotation, for Station 1)
safety goggles (1 pair per student, for Station 2)
beakers (50 mL, 2 for Station 2)
water (tap, 20 mL per group rotation, for Station 2)
vinegar (20 mL per group rotation, for Station 2)
graduated cylinders (10 mL, 2 for Station 2)
chalk (sidewalk - not dustless, 2 small equal-size
pieces per group rotation, for Station 2)
timing device (1 for Station 2)
safety goggles (1 pair per student, for Station 3)
beakers (small, between 10–50 mL, 2 for Station 3)
lemon juice (10 mL per group rotation, for Station
3)
ketchup (10 mL per group rotation, for Station 3)
graduated cylinder (10 mL, 1 for Station 3)
pennies (dull, 3 per group rotation, for Station 3)
timing device (1 for Station 3)
glue or tape (per group)
Weathering Station 1 – The sugar cubes should begin to crumble, and the edges
become more rounded.
Weathering Station 2 – Water should have little or no effect on the chalk. Some
bubbles may escape, but these should stop and are not to be confused with more
continuous bubbles from the vinegar and chalk chemical reaction. The vinegar
should cause bubbles to be released. Given enough time, the vinegar will
completely dissolve the chalk.
Attachments:
Weathering Station 3 – Both the lemon juice and ketchup are acidic. The pH of
lemon juice is about 2 and ketchup is 3.8. On the pH scale, 7 is considered
Teacher Resource: Lab Station 1- Mechanical
neutral. The ketchup removes more of the oxidation on the pennies quicker than
Weathering (see Advance Preparation, 1 for
the lemon juice does. Lemon juice may be diluted with water, so check the labels.
station)
Teacher Resource: Lab Station 2- Chemical
7. Say:
Weathering (see Advance Preparation, 1 for
station)
We are going to look at these processes in more detail. These processes
Teacher Resource: Lab Station 3- Chemical
all involve the breaking down of rock resulting in sediment.
Weathering (1 for station)
Teacher Resource: PowerPoint: The Process of
8. Distribute the Handout: Weathering Notes to each student. Inform students that
Weathering Rocks
you will be showing a PowerPoint presentation about the weathering of rocks. Project
Handout: Weathering Notes (1 per student)
the Teacher Resource: PowerPoint: The Process of Weathering Rocks.
Teacher Resource: Weathering Notes KEY
9. As you discuss the PowerPoint slides, students are to take notes on the graphic
organizer on the handout. Key terms are given in the presentation. The use of the
graphic organizer will allow students to visualize the mechanical and chemical
weathering of rock and appropriate examples. Co-construct the graphic organizer
with students to ensure they are recording the appropriate information and not too
many details. Point out the connections between the information on the PowerPoint
and station investigations.
Safety Note:
Goggles should be worn when dealing with acids.
Instructional Notes:
The concepts of weathering are introduced to students in
10. Note: Not all information in the presentation is required for student mastery, but is
provided for background and examples that students can visualize. The concepts of elementary grades. The TEKS for Grade 6 reinforce these concepts
and their application in rock formation.
weathering, erosion, and deposition are introduced to students in elementary
grades. The TEKS for Grade 6 reinforce these concepts and their application in rock
formation.
Science Notebooks:
11. Encourage students to add small sketches or notes to assist them in understanding
examples.
Students record all data tables, observations, and drawings in their
notebooks.
12. Instruct students to add the term sediment and a definition in their own words to their
notebooks.
13. Instruct students to affix their Weathering Notes handouts to their notebooks.
EXPLORE/EXPLAIN – Erosion and Deposition
Students record terms and definitions and affix their Weathering
Notes handouts.
Suggested Day 3
1. Divide the class into groups of 4–5 for station rotations. Prepare duplicate stations to
maintain small group sizes.
Materials:
2. Review safety and clean up procedures for each station, prior to beginning stations. (see Advance Preparation)
You may wish to review each station’s procedures, or you may allow students to read
plastic container (disposable, clear with lid, 1 for
the directions at each station.
Station A)
hole punch (hand held, 1 per teacher for Station A)
3. Instruct students to bring their notebooks to each station. They are to include the
sand (small amount, for Station A)
following in the notebooks for each station:
drinking straw (flexible neck,1 per student)
Last Updated 05/23/13
page 5 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
Complete title and number of the station
Any data tables on the station card
Any drawings/labeling requested on the station card
4. Rotate students through the two stations at your signal. Students should leave the
station in the condition in which they found it at the beginning of the rotation. Give
them a one minute warning before signaling movement to the next station.
clay (modeling, small amount, per group, for Station
A)
aluminum pan (1 per group, for Station B)
pipettes (2 per group, for Station B)
water (tap, small container, for Station B)
soil (small amount, per group rotation, for Station B)
tape or glue (per group)
5. Monitor groups, and assist as needed.
Attachments:
6. The general results of each station:
Erosion and Deposition Station A – The sand should move away from the
direction that the wind is blowing. Sand will pile up as it is deposited when the wind
stops flowing.
Erosion and Deposition Station B – The soil should form deltas near the base of
the hill. The water will run down the hill of soil, taking the path of least resistance.
If the water is released in the same spot, small gullies will form.
7. Say:
We are going to look at these processes in more detail. These processes
involve the moving of sediments and deposition of these particles.
Teacher Resource: Lab Station A- Wind Erosion
(1 for station)
Teacher Resource: Lab Station B- Water Erosion
(1 for station)
Handout: Erosion and Deposition Notes (1 per
student)
Teacher Resource: Erosion and Deposition
Notes KEY
Teacher Resource: PowerPoint: The Process of
Erosion and Deposition of Sediments
Safety Note:
8. Distribute the Handout: Erosion and Deposition Notes to each student. Inform
students that you will be showing a PowerPoint about erosion and deposition. Project Do not share straws, and dispose of used straws immediately.
the Teacher Resource: PowerPoint: The Process of Erosion and Deposition of
Sediments.
9. As you discuss the PowerPoint slides, students are to take notes on the graphic
organizer on the handout. Key terms are given in the presentation. The use of the
graphic organizer will allow students to visualize the mechanical and chemical
weathering of rock and appropriate examples. Co-construct the graphic organizer
with students to ensure they are recording the appropriate information and not too
many details. Point out the connections between the information on the PowerPoint
and the station investigations.
10. Instruct students to add the term sedimentation and a definition in their own words to
their notebooks.
11. Instruct students to affix their Erosion and Deposition Notes handout to their
notebooks.
EXPLORE/EXPLAIN – Sedimentary Rock
Instructional Notes:
The concepts of erosion and deposition are introduced to students
in elementary grades. The TEKS for Grade 6 reinforce these
concepts and their application in rock formation.
Science Notebooks:
Students record all data tables, observations, and drawings in their
notebooks.
Students record terms and definitions and affix their Erosion and
Deposition Notes handouts.
Suggested Day 4
1. Divide the class into groups of 3–4, and give each group a sedimentary rock sample.
Ask them to observe it.
Ask:
What is your rock made of? Answers may vary. Students should see sediment
such as sand and maybe a fossil.
Where do you think the sediment came from to make this rock? Answers
may vary. Students should come to the conclusion that the sediment that make
the rock came from other rocks that have been weathered.
What kind of rock do you think this is? (Sedimentary)
Where do you think the name sedimentary rock comes from? (It is named
because it is made of sediments.)
Materials:
Starburst™ candies (3–4 different colors per
group)
scissors (per student)
tape or glue (per group)
Attachments:
Teacher Resource: TheProcess of Forming
Sedimentary Rock (1 class set)
2. Give each group 3–4 different colors of the Starburst™ candies, and ask students to
pretend the candy is a representation of different rocks.
3. Instruct them to cut the candy into small pieces and draw what they have created in
their science notebook.
4. Ask:
If the Starburst™ is a rock, then what was the process that you used to
cut the “rock” into smaller pieces? (Weathering)
What do the small, broken down pieces of Starburst™ represent?
(Sediment) Students should label the pieces as such in their science notebooks.
Last Updated 05/23/13
Safety Note:
Warn students that scissors should be handled with care so they
do not cut themselves.
Misconception:
Students may think that all rocks are the same and
it's impossible to tell how they formed.
page 6 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
5. Instruct the students to gently press the “sediment” together and draw what they
create in their science notebook.
Ask:
What kind of rock was created? (Sedimentary) Instruct the students to label
their drawing as sedimentary rock.
What did you have to do to get the sediments to stay together? (Pushed
them together) Explain to students that this is called compaction. Explain to
students that this is part of the process of creating a sedimentary rock.
What might compact sediment in nature? Answers may vary. Guide students
to the weight of ocean water or layers of sediment that is deposited above this
sediment.
Why didn’t the pieces come apart after you set the rock down? (The candy
was sticky.) Explain to the students that this is called cementation. Explain to
students that when sediment is compacted, if conditions are right, then sediment
can be cemented together to form sedimentary rocks.
Science Notebooks:
Students draw and label the Starburst™ sediment and
sedimentary rock they create.
Students draw the picture from the reading, summarize how a
sedimentary rock is created, and list the examples of sedimentary
rocks, in their science notebooks.
Students record terms and definitions.
6. Instruct the students to draw an arrow from the sediments to the sedimentary rock
drawing in their science notebooks and label the arrow cementation and compaction.
7. Distribute the Teacher Resource: The Process of Forming Sedimentary Rock,
and instruct students to read through it. This may be done in groups, pairs, as whole
class, or individually.
8. Monitor students as they read the passage.
9. Once students have finished reading, instruct them to draw the picture from the
reading, summarize how a sedimentary rock is created, and list the examples of
sedimentary rocks, in their science notebooks. Instruct students to record the terms
compaction and cementation along with a definition for each in their own words in
their notebooks.
10. Monitor students as they work in their notebooks.
11. Show a picture of the Grand Canyon (see Advance Preparation), and ask students
to find a partner and discuss why they think the Grand Canyon is so big. Ask them to
come up with an explanation using the vocabulary words: weathering, erosion, and
deposition.
12. Have a few groups share what they thought, and guide them to the conclusion that
the solid rock that made up the land was broken into sediment by weathering. Then,
the land was carried away by the river and deposited somewhere downstream. Some
of the sediment made it all the way to the ocean.
Ask:
What do you think will happen to the sediment from the Grand Canyon?
Answers may vary. One thing that could happen is the sediment could be
compacted and cemented together with sediment from other rocks to form a new
sedimentary rock.
EXPLORE/EXPLAIN – Igneous Rock
Suggested Day 5
1. Project the Teacher Resource: PowerPoint: Sedimentary Rocks, and review the
process of the formation of sedimentary rocks through questioning.
2. Divide the class into groups of 3–4, and distribute the Teacher Resource: Sugar
Cube Rocks (see Advance Preparation) to each group.
3. Ask students to read the directions on the handout. Answer any questions that they
may have.
4. Review safety procedures for working with a hot plate. Also, remind students that
molten sugar can cause burns.
5. Instruct students to record observations and drawings, as well as answer all
questions in their science notebooks. Instruct them to make careful observations and
illustrations, as they will revisit this information later in the lesson.
6. Model each step, and monitor and assist students while they complete the activity.
7. Review the questions from the Teacher Resource: Sugar Cube Rocks.
Last Updated 05/23/13
Materials:
sugar cubes (2 per group rotation)
hand lens (4 per group)
ice (various per group rotation)
hot plate (1 per group)
aluminum foil (1, 8 cm square per group rotation)
petri dish (1 per group)
clothes pin (1, wooden, spring-type per group)
plate (small, plastic or foam per group)
tape or glue (per group)
Attachments:
Teacher Resource: Power Point: Sedimentary
page 7 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
8. Distribute the Teacher Resource: The Process of Forming Igneous Rock, and
allow students time to read through the material. This can be done as a whole class,
pairs, small group, or individual activity.
9. Monitor students as they read the passage.
10. Once students have finished reading, instruct them to draw the picture from the
reading, summarize how an igneous rock is created, and list the examples of igneous
rocks, in their science notebooks. Instruct students to record the terms intrusive and
extrusive along with a definition for each in their own words in their notebooks.
11. Monitor students as they work in their notebooks.
Rocks
Teacher Resource: Sugar Cube Rocks (1 per
group)
Teacher Resource: The Process of Forming
Igneous Rock (1 class set)
Safety Note:
Review safety procedures for working with a heat source and hot
material.
12. Ask:
What is the process that creates all igneous rocks? (Melting and cooling)
What is the difference between an intrusive rock and extrusive rock?
Answers may vary. Intrusive rocks are formed inside of the Earth, take longer to
cool, and grow larger crystals than extrusive rocks that form by cooling on the
surface of Earth
Instructional Note:
Students have learned about the formation of sedimentary rocks in
Grade 5, but the information on igneous and metamorphic rocks is
introductory.
Science Notebooks:
13. How can we remember the difference? Answers may vary. INtrusive rocks cool
INside the Earth and EXtrusive rocks EXit the Earth.
Students illustrate and describe various steps of the sugar cube
rocks lab and answer the questions in their science notebooks.
Students draw the picture from the reading, summarize how an
igneous rock is created, and list the examples of Igneous rocks, in
their science notebooks.
Students record terms and definitions.
EXPLORE/EXPLAIN – Metamorphic Rock
Suggested Day 6
1. Project the Teacher Resource: PowerPoint: Igneous Rocks, and review the process
of the formation of igneous rocks through questioning.
2. Display different colored wax crayons, and explain to students that the crayons
represent rocks. Using the scissors, begin shaving down the crayons into smaller
pieces.
Ask:
What process am I modeling by shaving pieces of the crayons off?
(Weathering)
What do the smaller pieces of crayon represent? (Sediment)
How could I create a crayon sedimentary rock? (By compacting the pieces
together)
3. Place the pieces into a square of aluminum foil, and then fold the foil so that all
edges are sealed.
4. Press down on the foil so that the pieces of crayons will compact.
5. Open the foil, and show the students what was created.
Say:
Materials:
wax crayons (different colors, per teacher
demonstration)
scissors (1 per teacher demonstration)
aluminum foil (1 roll, per teacher demonstration)
hot plate (1 per teacher demonstration)
safety goggles (1 per teacher)
tape or glue (per group)
Attachments:
Teacher Resource: PowerPoint: Igneous Rocks
Teacher Resource: The Process of Forming
Metamorphic Rock (1 class set)
Safety Note:
This is a representation of a sedimentary rock. I have used some
pressure to compact the sediment together. Show students that the crayon
pieces are stuck together, but show how easily the “rock” breaks apart. Metamorphic rocks are created with even more pressure and heat. I will
demonstrate how a metamorphic rock is created.
6. Refold the aluminum foil, and place it on the hot plate for just a couple of seconds;
this is enough time for the wax to soften, but not completely melt.
7. Once the wax is warm and soft, remove it from the hot plate and reapply pressure
using a book or something flat and heavy.
8. Open the foil, and show the students what was created.
Ask:
What is the difference between the metamorphic crayon rock and the
sedimentary crayon rock? Answers may vary. The metamorphic rock looks
Last Updated 05/23/13
Safety goggles should be worn when using scissors to shave
crayons.
Instructional Notes:
You might need to practice the demonstration before class to find
out the length of time required for the wax to soften but not melt
completely.
Optional: If time permits, allow students to use the materials to
model the process of the formation of a metamorphic rock.
Science Notebooks:
Students draw the picture from the reading, summarize how a
page 8 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
similar, but the crayon pieces look more blended together. The pieces of crayon
may appear larger. The metamorphic rock is denser and it is harder to break
apart.
9. Distribute the Teacher Resource: The Process of Forming Metamorphic Rock,
and allow students time to read through the material. This can be done as a whole
class, pairs, small group, or individual activity.
metamorphic rock is created, and list the examples of
metamorphic rocks in their science notebooks.
Students record terms and definitions.
10. Monitor students as they read the passage.
11. Once students have finished reading, instruct them to draw the pictures from the
reading, summarize how a metamorphic rock is created, and list the examples of
metamorphic rocks, in their science notebooks. Instruct students to record the terms
foliated and non-foliated along with a definition for each in their own words in their
notebooks.
12. Monitor students as they work in their notebooks.
13. Ask:
What is the process needed to create a metamorphic rock? (Heat and
pressure)
What is the difference between a foliated and non-foliated rock? Answers
may vary. Foliated rocks have stripes and form under large amounts of uneven
pressure. Non-foliated rocks do not have stripes, but may develop larger crystals.
EXPLORE/EXPLAIN – Rock Cycle
Suggested Day 7
1. Project the Teacher Resource: PowerPoint: Metamorphic Rocks, and review the
process of the formation of metamorphic rocks through questioning.
2. Project the Teacher Resource: Rock Cycle Guide KEY.
Materials:
tape or glue (per group)
3. Distribute the Handout: Rock Cycle Guide to each student.
4. Guide students through the rock cycle, stressing the processes that change and
form rocks. Instruct students to fill in the empty boxes on their guide as you discuss
the rock cycle process.
5. Inform students of the following about the rock cycle:
There is not a set rotation or direction through the rock cycle.
A rock may become several types of rock during the cycle.
Not all rocks will change to all three types of rocks.
It can take millions of years for a rock to change to another type of rock.
6. Ask:
What is the difference between erosion and weathering? (Erosion is the
process of moving sediment or weathered rock from one place to another.
Weathering is the process of breaking down material into smaller pieces.)
Before a rock can change into an igneous rock, what must happen first?
(It must melt and become magma.)
What is the difference between magma and lava? (Magma is molten material
below the surface of the Earth. Once magma reaches the surface of the Earth, it
is called lava.) It can be ejected from a volcano or seep onto the sea floor.
Which process forms an igneous rock from magma? (Cooling of molten
material)
Which processes form metamorphic rocks? (Heat and pressure)
What do all rocks go through before they become sediment? (Weathering,
erosion, and deposition)
Which processes form sedimentary rocks from sediment? (Compaction
and cementation)
By looking at the diagram, how can you be sure a sedimentary rock can
turn into a sedimentary rock again? (A sedimentary rock can be weathered
into sediment and then cemented and compacted with other sediment to form a
sedimentary rock.)
Is the rock cycle a circle? Explain your answer. Answers may vary; however,
student answers may include that rocks may undergo a process several times or
that rocks may change between two forms without ever becoming all three forms
Attachments:
Teacher Resource: Power Point: Metamorphic
Rocks
Teacher Resource: Rock Cycle Guide KEY (1 for
projection)
Handout: Rock Cycle Guide (1 per student)
Handout: Rock Cycle Practice (1 per student)
Teacher Resource: Rock Cycle Practice KEY
Instructional Notes:
It may be helpful to project a copy of the handout while explaining.
Students can add color to reinforce concepts.
Instruct students to attach the rock cycle practice to their notebooks,
as they will need it later in the lesson.
The rock cycle is an illustration that is used to explain how the three
rock types are related to each other and how Earth processes
change a rock from one type to another through geologic time. A
trip through the rock cycle takes millions of years. Plate tectonic
movement is responsible for the recycling of rock materials and is
the driving force of the rock cycle.
Check For Understanding:
Consider using the Who Are We? card sets to formatively assess
students.
Science Notebooks:
Students affix the Rock Cycle Guide and the Rock Cycle Practice
handouts to their notebooks.
7. Divide students into pairs or groups of three.
Last Updated 05/23/13
page 9 of 33 Grade 6
Science
Unit: 09
Lesson: 02
Suggested Duration: 8 days
8. Distribute a copy of the Handout: Rock Cycle Practice to each student.
9. Ask the students to work together, using their Handout: Rock Cycle Guide, to fill in
the empty bubbles with the correct processes to complete the diagram. Inform
students that they will have to analyze their guide to determine where to place
information on their Rock Cycle Practice handout.
10. Monitor and assist students as needed, and review the correct answers when the
students finish.
11. Instruct the students to affix the Handouts: Rock Cycle Guide and Rock Cycle
Practice to their science notebooks.
ELABORATE – Rocks and Their Formation Tabbed Organizer
Suggested Days 7 (continued) and 8
1. Regroup students, or allow them to remain in the same groups.
Materials:
2. Distribute a sheet of blank paper to each student.
3. Instruct students to fold a piece of paper in half, from top to bottom. Cut the top
piece, from the edge to the fold, into three sections.
4. Instruct students to label the front of the flaps with the names of each of the three
rock types.
5. Distribute a labeled sample of each rock type to each group and hand lenses for
observation.
6. Allow students some time to observe the three different types of rocks.
7. Explain to students that they will use the information in their science notebooks to
write definitions, observations, draw a picture, and write the processes that create
each rock type.
Sedimentary rock: A sedimentary rock is made of sediment of other rocks that
have been weathered, eroded, and deposited, then compacted and cemented
together to form a new rock. Observations may vary.
Metamorphic rock: Rocks transformed by heat and/or pressure into a new rock
with different properties. Observations may vary.
Igneous rock: An igneous rock comes from magma or lava that solidified as it
cooled. Observations may vary.
rocks (samples of igneous, sedimentary, and
metamorphic, 1 each per group)
paper (blank, 1 sheet per student)
scissors (1 pair per student)
hand lens (1 per student)
tape or glue (per group)
Instructional Note:
Unfolded sample:
Check For Understanding:
The three tabbed organizer is a great opportunity for a formative
assessment.
8. Monitor and assist students while they complete the activity. Approve each group’s
work by facilitating the correct placement of components through guided questioning.
EVALUATE – Performance Indicator
Suggested Day 8 (continued)
Grade 06 Science Unit 09 PI 02
Materials:
Create a museum exhibit on rocks. In the exhibit, classify samples of rocks as metamorphic,
igneous, or sedimentary by the processes of their formation.
Standard(s): 6.2E , 6.10B
ELPS ELPS.c.1C , ELPS.c.5C
1. Refer to the Teacher Resource: Performance Indicator Instructions KEY for
information on administering the assessment.
rocks (samples of igneous, sedimentary, and
metamorphic, 1 per student)
reference books about rocks (various per class)
materials to create displays (colored paper, egg
carton sections, cardstock, blocks, foam packing,
etc., various per class)
Attachments:
Teacher Resource: Performance Indicator
Instructions KEY (1 for projection)
Last Updated 05/23/13
page 10 of 33 Grade 6
Science
Unit: 09 Lesson: 02
Who Are We?
Clue Card
One of us is formed underground
from slowly cooling magma.
One of us is formed from lava
being ejected from a volcano.
One of us is volcanic glass
formed from rapidly cooling lava.
Clue Card
One of us used to be a rock
known as shale.
One of us used to be a rock
known as limestone.
We formed under pressure and
heat.
Metamorphic Rocks
©2012, TESCCC
Igneous Rocks
05/23/13
page 1 of 3
Grade 6
Science
Unit: 09 Lesson: 02
Clue Card
One of us was eroded so quickly
that there wasn’t time for the
particles to weather to sand
before forming.
One of us is made from pieces of
sand cemented together into rock.
One of us is made of tiny
skeletons of microscopic
organisms that lived in ancient
shallow seas.
Clue Card
One of us makes up about 60% of
the continental crust.
One of us is found in almost every
rock.
We can be found in granite.
Sedimentary Rocks
©2012, TESCCC
Minerals
05/23/13
page 2 of 3
Grade 6
Science
Unit: 09 Lesson: 02
Image Citations:
http://commons.wikimedia.org/wiki/File:Scoria_Macro.JPG
http://commons.wikimedia.org/wiki/File:Black_obsidian.JPG
http://commons.wikimedia.org/wiki/File:Itu_granite.JPG
http://commons.wikimedia.org/wiki/File:Slate_(thick).JPG
http://commons.wikimedia.org/wiki/File:Brown_Marble.jpg
http://commons.wikimedia.org/wiki/File:Woodton_conglomerate.JPG
http://commons.wikimedia.org/wiki/File:Sandstone_erosion.jpg
http://commons.wikimedia.org/wiki/File:JeanMarie_Limestone.JPG
http://commons.wikimedia.org/wiki/File:Feldspar_3409.jpg
http://commons.wikimedia.org/wiki/File:Quartz_Br%C3%A9sil.jpg
©2012, TESCCC
05/23/13
page 3 of 3
Grade 6
Science
Unit: 09 Lesson: 02
Lab Station #1- Mechanical Weathering
Effect of Gravel on Sugar Cubes
Materials:



small, clear, plastic container with lid
small handful of gravel
sugar cubes (5)
Procedure:
1. Record all information in your notebooks.
2. Draw the data table below in your notebooks.
3. Observe the appearance and shape of a sugar cube and the gravel, and sketch the cube in your
notebooks. Include a written description of your observation.
4. Place a small handful of gravel into the container.
5. Add five sugar cubes to the container, and secure the lid.
6. Gently shake the container in an up and down direction for the number of shakes specified in the
chart.
7. Open the container after each specified number of shakes, and observe the condition of the
contents. Describe the condition of the cubes in the notebooks. Make a drawing of the sugar after
60 shakes.
8. Dispose of the sugar, and wipe the gravel with a dry paper towel. Return the gravel to its original
container.
Before Shaking
After 10 Shakes
After 30 Shakes
After 60 Shakes
Sugar
Gravel
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Lab Station #2- Chemical Weathering
Effect of Water and Vinegar on Chalk
Materials:








safety goggles
small beakers (50 mL) (2)
20 mL of tap water
20 mL of vinegar
10 mL graduated cylinders (2)
small, equal-size pieces of sidewalk chalk (not dustless) (2)
hammer
timing device
Safety Note: Wear safety goggles.
Procedure:
1. Record all information in your notebooks. Draw the data table below in your notebooks, and
record the information.
2. Measure and pour 20 mL of water into one of the two beakers.
3. Measure and pour 20 mL of vinegar into the other beaker.
4. Try to break the two pieces of chalk to be the same length. The goal is to have approximately the
same amount for each container.
5. Place one piece of chalk inside a folded piece of paper towel. Crush the chalk by stepping on the
towel or gently tapping it with the hammer. Repeat this with the other piece of chalk.
6. At the same time, add the crushed pieces of chalk to each of the containers. It may be necessary
to add a little more of each liquid (in equal amounts) to ensure that the chalk is covered by liquid.
7. Observe and record at the time intervals listed below.
Chalk
At Start
After 3 Minutes
After 6 Minutes
After 9 Minutes
Water
Vinegar
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Lab Station #3- Chemical Weathering
Effect of Lemon Juice and Ketchup on Copper Pennies
Materials:

safety goggles

dull pennies (3)

small beakers (between 10–50 mL) (2)

timing device

10 mL of lemon juice

paper towels

10 mL of ketchup

container of water

10 mL graduated cylinder
Safety Note: Wear safety goggles.
Procedure:
1. Record all information in your notebook. Draw the data table in your notebook, and record the
information.
2.
Measure and pour 10 mL of lemon juice into one beaker.
3.
Measure and pour 10 mL ketchup into the other beaker.
4.
Place one dull penny on the lab station for an example of what it looked like before immersion.
Describe the penny at your table.
5.
Place one dull penny in each beaker for five minutes. Remove the pennies, and rub each one
between your index finger and thumb before rinsing. Compare how the penny looked before and
after. Describe the pennies in the table.
6.
Wash the two pennies that were in the acid, and place them in the container designated by your
teacher.
7.
Wash your hands, dispose of used lemon juice and ketchup, and restore station to prepare for
next group.
Pennies
Observations and Drawings
Old Penny
Lemon Juice
Ketchup
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Weathering Notes
WEATHERING
MECHANICAL
©2012, TESCCC
CHEMICAL
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Weathering Notes KEY
WEATHERING
The breaking down of rock into smaller pieces that remain next to each other.
Weathering forms sediment. There are two types:
MECHANICAL
CHEMICAL
Physical breaking of rock without any change in the
chemical composition of the rock
Ice Wedging
Exfoliation
©2012, TESCCC
Thermal
Biotic
(force)
The breaking down of rock into smaller pieces because
of chemical changes within the rock
Oxidation
11/30/12
Hydrolysis
Carbonation
Biotic
(acid)
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Lab Station A- Wind Erosion
Materials:
 disposable, clear, plastic container with lid
 hand held hole punch
 small amount of sand
 flexible-neck drinking straws
 clay
Safety Note: Use a clean straw for each student.
Procedure:
1. Use a hole punch to make a hole in the side end of a plastic container, about
halfway up the container. It may be necessary to place two holes overlapping to get
a hole large enough to place the straw through. (This step may have been done for
you by your teacher.)
2. Make a sand hill in the container. Make sure the lid is secure. Do not place the sand
hill too close to the end of the container with the hole in it.
3. Place a drinking straw into the hole. Use a rope of clay to place around the hole
where the straw enters. Make sure that the area around the straw is sealed with the
clay.
4. Angle the straw neck upward, and blow gently into the straw. Observe and record
what happens in your notebooks.
5. Blow in the straw again, but with more force. Again, observe what happens, and
record it in your notebooks.
6. Remove the straw, and dispose of it. Remove the sand from the container, and
return it to its original container. Place your container in the area designated by your
teacher. Clean up any sand that has spilled.
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Lab Station B- Water Erosion
Materials:
 soil
 aluminum pan
 pipettes or drinking straws
 container of water
Procedure:
1. Make a soil hill in the middle of a small, aluminum pan. Press down on the soil
slightly to create the hill.
2. Use the pipettes or straws to release a stream of water at the top of the hill.
Observe what happens, and record it in your notebooks.
3. Repeat, releasing water five more times. Observe, describe, and illustrate what
happens and record in your notebooks.
4. Describe the pattern of deposition seen at the foot of the soil hill.
5. Pour the water out of the pan, and place the soil in the container designated by your
teacher.
©2012, TESCCC
11/30//12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Erosion and Deposition Notes
Transport and Relocation of Sediment
DEPOSITION
EROSION
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Erosion and Deposition Notes KEY
Transport and Relocation of Sediment
DEPOSITION
EROSION
The moving of rock material from one place to another
The laying down of sediments that were carried to a new
location from another location
Glacial
Wind
Ice
Waves
Wind
Water
©2012, TESCCC
Gravitational
Bioerosion
11/30/12
Water
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
The Process of Forming Sedimentary Rock
Sedimentary rocks make up about 70–75% of the rocks at the Earth’s surface. They form in
environments such as beaches, rivers, the ocean, and anywhere that sand, mud, clay, and other
types of sediment collect, but are mostly formed in water.
A sedimentary rock is a layered rock that is formed from the processes of compaction and
cementation of sediments. These rocks are formed from sediment that has been weathered,
eroded, and deposited from existing rock and other material, such as plants or animal remains.
Sedimentary rocks are the only rocks in which fossils can be preserved. Sediments undergo the
process of lithification (becoming rock) by compacting under pressure and filling pore space by
cementation.
Compaction occurs when layers of sediment are pressed together under the weight of multiple
layers of rock and sediment. This pressure on the layers reduces the thickness of each of the
original layers, somewhat like a trash compactor. The reduction of the thickness causes the
spaces around the layers to be reduced as well. The result is tighter packed layers.
Cementation occurs when dissolved minerals solidify within the spaces between the particles of
sediment. Dissolved minerals fill in the spaces between the sediment particles. Solid rock forms
as the minerals act like glue to hold the sediments together. Calcite and silica are two common
minerals that act as cement.
Sedimentary rocks are classified by how they are formed. The following are different types of
sedimentary rocks:
Shale is composed of silt or clay that has been compacted or squeezed together to form a solid
rock. Shale forms in quiet waters such as swamps and bogs.
Sandstone forms when grains of sand are cemented together to form solid rock. Crystals grow
from the dissolved minerals in the spaces around the sand grains. Solid rock is formed from the
sand grains as the crystals fill in the spaces.
Conglomerates form by the cementing of pebble-size rock fragments.
Limestone forms as tiny pieces of shells and the skeletal remains of dead sea animals are
cemented together.
Chert can form from recrystallization of silicon rich skeletons, such as glass sponges and
diatoms.
Halite, commonly called rock salt, is a chemically formed sedimentary rock. It is formed by the
evaporation of salt water from shallow oceans or seas.
Coal is compressed vegetation.
©2012, TESCCC
05/23/13
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Sugar Cube Rocks
Materials:




sugar cubes (2)
hand lens
ice
petri dish


hot plate or tea light
candle
aluminum foil


wooden, spring-type clothes
pin
small, plastic or foam plate
Part 1:
Procedures:
1. Record the required information in your notebooks.
2. Place some ice on the plastic plate, and set it aside.
3. Examine a sugar cube with a hand lens. In your science notebook, describe and illustrate how
the cube looks.
4. Rub the two sugar cubes together, over a petri dish, to form a powder. Observe the powder with
the hand lens. In your science notebook, describe and illustrate how the cube looks.
5. Make a “boat” with your foil. Pour the crushed sugar into the foil boat.
6. Safety Note: Follow safety procedures when using the hot plate. Use the clothes pin to place
and remove the boat on the hot plate or to hold it over the candle flame. Observe the sugar as it
begins to melt. In your science notebook, describe how the heat is changing the sugar.
7. Set the foil boat on top of the ice. Let the sugar cool and harden. Safety Note: Do not touch the
sugar until it has cooled.
8. Break the hardened sugar into pieces. Look at the pieces with a hand lens. In your science
notebook, describe and illustrate how the sugar rock looks now.
Answer the following questions in complete sentences in your science notebooks.
1. In step #3, how was the sugar cube like sedimentary rock?
2. In step #4, what process did rubbing the cubes together represent?
3. In step #5, what process did moving the sugar rock sediments to the boat represent?
4. In step #6, where on earth would there be enough heat to melt rocks?
5. In step #6, what process did melting the sugar represent?
6. In step #7, what process does cooling of molten sugar rock represent?
7. In step #7, what type of rock does the sugar rock represent?
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
The Process of Forming Igneous Rock
The word “igneous” is from the Latin ignis which means “of fire”. Igneous rocks are formed by the
melting of rock, turning it into magma or lava, and then cooling off again. The rate at which the molten
rock cools causes specific sizes and types of crystals.
The rocks can be classified by where they are formed and their crystal size.
 Extrusive rocks form when the lava cools and crystallizes (hardens) on the surface of the
Earth. Igneous rocks that are formed above ground are called volcanic. If magma makes it to
the surface, it is known as lava and it will erupt or explode from a volcano and then cool and
crystallize to form an extrusive rock. The crystals will be very small and may have to be seen
with the aid of a microscope. An example would be obsidian.
 Intrusive rocks form when the magma cools and crystallizes below the Earth’s surface.
Intrusive rocks become exposed after millions of years by the processes of uplift, mountainbuilding, weathering, and erosion. If the magma cools slowly and crystallizes below the
surface, it will form an intrusive rock. The crystals will be large enough to see with an unaided
eye. An example would be granite.
Igneous rocks are also classified by the size of their crystals. Magma is a mixture of molten (liquid)
rock, crystals, and gas. Magmas are less dense than surrounding rocks and will move upward.
Because cooling of the magma takes place at different rates, the crystals that form and their texture
exhibit different properties.
Igneous rocks can form under water as well as on the land. Hot magma oozes out as lava along the
rifts or cracks in the seafloor. The extremely hot lava starts changing from liquid to solid as it meets
the cold seawater and begins cooling. The Hawaiian Islands are chains of volcanic peaks that have
risen above the surface of the ocean.
Some common igneous rocks are:
 Basalt – extrusive rock that cools quickly so crystals are not visible to the unaided eye. It
makes up about 90% of the Earth’s crust and lines the ocean basins.
 Gabbro – intrusive rock that has the same chemical composition and minerals as basalt. It is
the most common rock in the oceanic crust.
 Granite – intrusive rock that cools very slowly (hundreds of thousands of years) so the crystals
are large and visible. It makes up much of the Earth’s continental crust. Granites can be found
in a wide range of colors.
 Obsidian – extrusive rock that cools so quickly that it doesn’t have time for crystals to form. It
is sometimes called volcanic glass and has a sharp edge when broken.
 Tuff – extrusive ash and dust ejected by a volcano. The glass-like ash forms when escaping
gas forces a fine spray of magma from the volcano. When it settles on the ground, tuff hardens
to rock as it cools.
 Pumice – extrusive foamy volcanic glass with gas trapped inside. The gas escapes as the
rock cools. The holes that remain allow pumice to float in water. It is composed mostly of SiO 2
(silicon dioxide).
©2012, TESCCC
11/30/12
page 1 of 2
Grade 6
Science
Unit: 09 Lesson: 02
Extrusive
Fast cooling;
Igneous
Tiny crystals
form
Rock
Intrusive
Igneous
Rock
Slow cooling;
Medium cooling;
Large crystals
form
Medium crystals
form
©2012, TESCCC
11/30/12
page 2 of 2
Grade 6
Science
Unit: 09 Lesson: 02
The Process of Forming Metamorphic Rock
The term metamorphic comes from the following Greek terms: meta = change and morph = form.
Therefore, metamorphism means to change form. Metamorphic rocks are found in the Earth’s
continental crust. The process of metamorphism does not completely melt the rocks, but changes them
into other rocks which are denser and more compact. It can take millions of years to form metamorphic
rocks.
At extremely hot temperatures, the crystal structures of the minerals that make up the rock are broken
down. By using different combinations of the available elements and compounds in the rock, new
minerals are created. Buried rocks are under a huge amount of pressure because of the weight of
sediments and rocks above them. Pressure can also be exerted on rocks due to the forces of tectonic
processes. The most obvious effect of pressure on rocks is the reorientation (changing direction) of
mineral crystals.
Below are some examples of existing rocks and the metamorphic rock that they may become:
Sedimentary
Metamorphic
Igneous
Limestone changes to marble.
● Phyllite changes to schist. ● Granite can change into gneiss.
Sandstone changes to quartzite. ● Schist changes to gneiss. ● Basalt changes to greenstone.
Shale changes to slate.
Recrystallization occurs as the particle size of the rock changes during the process of metamorphism.
In order for the process of recrystallization to occur, both high temperatures and pressures must be
present. Crystals in metamorphic rock may not always be visible without the use of a microscope.
Textures of metamorphic rocks are separated into two categories: foliated and non-foliated. Foliated
rock is caused by uneven pressure that deforms the rock, making it appear to have stripes. The
pressure is greater in one direction than another. The uneven pressure causes the minerals in the
original rock to rearrange in one plane. This will reduce the overall pressure on the rock and give it a
striped look. Slate is an example of foliated rock.
Non-foliated rock is formed in areas of high temperatures and low pressure. The pressure is equal from
all sides. This rock does not appear to have stripes, but the combination of high temperatures and low
pressure causes the minerals in the original rock to recrystallize into larger sizes. The atoms become
more tightly packed together, and this increases the density of the rock. Quartzsite is an example.
©2012, TESCCC
05/23/13
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
The Rock Cycle Guide KEY
Magma
cooling
melting
melting
Metamorphic Rock
Igneous Rock
heat & pressure
heat &
pressure
weathering, erosion, &
deposition (sedimentation)
weathering, erosion,
& deposition (sedimentation)
Sedimentary Rock
Sediment
compaction &
cementation
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
The Rock Cycle Guide
melting
heat &
pressure
weathering, erosion,
& deposition (sedimentation)
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Rock Cycle Practice
Magma
Sedimentary Rocks
Igneous Rocks
Sediment
Metamorphic Rocks
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Rock Cycle Practice KEY
Magma
Cooling
(Crystallization)
Melting
Sedimentary Rocks
Igneous Rocks
Cementation
& Compaction
Heat &
Pressure
Sediment
Weathering,
Erosion,
&
Deposition
Metamorphic Rocks
©2012, TESCCC
11/30/12
page 1 of 1
Grade 6
Science
Unit: 09 Lesson: 02
Performance Indicator Instructions KEY
Performance Indicator
Create a museum exhibit on rocks. In the exhibit, classify samples of rocks as metamorphic,
igneous, or sedimentary by the processes of their formation.
(6.2E; 6.10B)
1C; 5C
Materials:
rocks (samples of igneous, sedimentary, and metamorphic, 1 per student)
reference books about rocks (various per class)
materials to create displays (colored paper, egg carton sections, cardstock, blocks, foam
packing, etc., various per class)
Instructional Procedures:
1. Ensure that each student has a rock to exhibit, only labeled with its name. Consider using less
familiar samples if resources are available.
2. Instruct students to use their notebooks to assist them in this task. Students may need access to
computers/Internet and reference books to identify their rock sample type.
3. Individual rocks will be displayed in a class museum collection. Each student is to create a small
display box or stand for his or her rock. Suggestions to share with students for a small display box
or stand for rocks:
colored construction paper
egg carton- cut the individual cups apart; use upright or upside down, depending on the size of
rocks
build a cube out of cardstock
wood block
foam packing cut to size, etc.
4. Students will create a label for their rock which includes the following:
name of the rock
type of rock
process of formation
student name goes on the back of the label
5. Check student work for accuracy before allowing them to display their rock and label.
6. Instruct students to brainstorm ways to organize their rocks to create a cohesive classroom
exhibit, beyond just igneous, metamorphic, or sedimentary. For example, they might place the
rocks in sub-categories based on size, color, or type.
©2012, TESCCC
05/23/13
page 1 of 2
Grade 6
Science
Unit: 09 Lesson: 02
Instructional Notes:
Gather a variety of the three types of rocks. Marble, limestone, and scoria pieces are available from
landscaping places. Use rock kits if available.
Check with a local Geological Society or the USGS to request samples for educational purposes.
NOTE: Students are not expected to recognize types of rocks based on visual observations.
Consider putting your class exhibit on display in a multi-use area of your campus; for example, the
library or a display case.
Invite individuals to visit the exhibit so students can explain how rocks form.
©2012, TESCCC
05/23/13
page 2 of 2