Lesson Plan
Date: 10/27/2008
Type of Lesson
Whole Class: X
Small Group:
Tutoring:
Subject: Sedimentary rocks are mixtures
Rationale: This lesson will show that mixtures can be separated into ordered units
without human interaction. The lesson also provides the students with the opportunity to
see how I relate mixtures to my research in stratigraphy and provide real world examples
of uses for what they are learning in the classroom.
New Jersey Core Curriculum Content Standards: 5.3: The students will integrate
mathematics as a tool for problem solving (percentages of minerals in rocks). 5.8: The
students will gain an understanding of the structure, dynamics and geophysical systems
of the earth (rocks). 5.10: All students will develop an understanding of the environment
as a system of interdependent components affected by human activity and natural
phenomena.
Goals and Objectives: Students will be able to identify two of the basic sedimentary
rock types (sandstones and shales) based on their grain sizes and see how grain size
affects the way the rock forms.
Materials Needed:
For each group:
1 – settlement tube (2” diameter) filled with water to 30 cm depth
1 – small cup of silt
1 – small cup of sand
1 – small cup of fine gravel
1 – small cup of coarse gravel
1 – stopwatch
For each student:
1 – activity sheet (attached)
1 – identification chart (attached)
Anticipatory Set/Engagement: Classroom discussion of different rock formations the
students may have seen while driving on the roads. Include pictures of specific examples
that I want to focus on and how or where they think they might have formed.
Instruction: Each group will first obtain all the materials listed above.
Step 1: Put a few grains of sand into the settlement tube and record the amount of time it
takes to sink to the bottom.
Step 2: Repeat step 1 with the three other samples, using the silt last.
Step 3: Write down your observations of how long it took each sample to sink to the
bottom and discuss possible reasons for your findings.
Step 4: Mix all four samples together in one cup so that you have a heterogeneous
mixture.
Step 5: Make a prediction based on your results from step 3 as to what will happen when
you pour the mixture into the settlement tube and why.
Step 6: Pour the mixture into the settlement tube and carefully observe what happens.
Step 7: Draw the outcome and state whether or not your prediction was correct, include
proof by summarizing the outcomes.
Step 8: Identify the different rock types present in the settlement tube based on grain size
and the attached identification sheet.
Assessment: Students will discuss their results with the rest of the class and explain why
the materials settled out the way they did and what rock types that resulted in.
Homework: The students are to go home and write a short paragraph about how the time
of settlement of each different material could be related back into depositional setting for
that particular rock.
Another possible homework would be for the students to go home and find a picture of a
rock outcrop and state what types of rocks are present based on the grain sizes.
Identification Chart:
Sandstone: Has mineral grains that can be seen by the naked eye. Rock usually has a
slightly rough texture.
Shale:
Has mineral grains that cannot be seen by the naked eye. Rock usually has a
fairly smooth texture due to small grains.
Student Work Sheet:
Material Name
Depth of Water
Silt
30 cm
Sand
30 cm
Fine Gravel
30 cm
Coarse Gravel
30 cm
Settlement Time
(sec)
Discuss why the materials took different times to settle the same distance and relate
that to likely conditions of deposition for a rock with that sized particle.
Predict what will happen when you pour the mixture of materials in the settlement
tube, support your predictions with examples.
Draw your final outcome and state if your prediction was correct or not.
What rock types are present in the settlement tube and in what order, support your
answer with evidence from the experiment.