METAMORPHIC ROCKS
We’ve looked at igneous and sedimentary rocks. In order to have the
most accurate information about rock types and their relationship to
Calvert Cliffs, we must still investigate the last group of rocks,
metamorphic rocks. Metamorphic rocks are rather unique because they
are rocks that are in the process of “changing forms.” You might think to
yourself, “What exactly does that mean? How is it possible for rocks to
change forms?” Let’s take a closer look and find out.
Objective
When you have completed this investigation, you should be able to
1.
analyze the characteristics of metamorphic rocks in order to describe the process that form
metamorphic rocks.
Materials (per group):
Various metamorphic rock samples
Hand lens
Procedure
Activity 1:
1.
Observe the two examples of metamorphic rocks provided by your teacher.
2.
One rock is a foliated metamorphic rock. The other rock is a nonfoliated metamorphic
rock. Predict the difference between foliated and nonfoliated metamorphic rocks.
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3.
Brainstorm a list of conditions that might be needed to form these types of rocks.
4.
Share your list with your group and modify your list as needed.
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Activity 2:
5.
Use the resources provided by your teacher to gather information about the processes that
form metamorphic rocks.
6.
Complete Chart 1, “Formation and Classification of Metamorphic Rocks” as you gather
information about the formation and types of metamorphic rocks.
Chart 1:
Formation and Classification of Metamorphic Rock
Formation of Metamorphic Rock
Classification of Metamorphic Rocks
Contact
Metamorphism
Description of
metamorphic rock
formation:
7.
Nonfoliated rocks
Description of
metamorphic rock
formation:
Definition:
Definition:
Examples:
Examples:
Classify your rock samples into foliated and nonfoliated metamorphic rocks in Chart 2:
Examples of Metamorphic Rocks”
Chart 2:
Examples of Metamorphic Rocks
Foliated Metamorphic Rocks
Nonfoliated Metamorphic Rocks
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8.
Explain how you used the characteristics of the different metamorphic rocks to classify
them.
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Analysis
1.
Use Figure 1, to complete Chart 3, “Formation of Metamorphic Rocks”
Figure 1
Shale
Slate
Schist
Gneiss
(sedimentary)
(metamorphic)
(metamorphic)
(metamorphic)
Increasing intensity of Heat and Pressure
Chart 3:
Formation of Metamorphic Rocks
Metamorphic
Rock
Original Rock
Slate
Shale
Type of Original Rock
(sedimentary, igneous, or
metamorphic)
Foliated or
Nonfoliated
Slate
Metamorphic
Foliated
2.
Describe what happens to the bands or layers of the rock as the intensity of heat and pressure
increases.
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3.
Marble is a beautiful and durable metamorphic rock that is often used in the design of
fireplace mantels, floors, and statues. However, marble originated from the
sedimentary rock, limestone. Summarize the processes that are involved in changing
limestone into marble. Use evidence from the investigation to support your response.
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Fossil Fact:
Suppose that sandstone, a sedimentary rock, contained a fish fossil. Due
to the movement of tectonic plates this rock is exposed to high heat and
pressure and becomes the metamorphic rock, quartzite.
Determine if the new rock, quartzite, would still contain the fish fossil.
Use evidence from the investigation to support your response.
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