Investigation 8
How does the rock cycle function
in the ocean?
Introduction
Points
|380
If you go outside, and walk on the bare earth, you’re walking on the lithosphere. We know that the ocean is a
primary province in the hydrosphere, but does the lithosphere play a part, too? The answer is yes, on the
seafloor. In this investigation, you will be examining rock types to determine where they might form in the
ocean. You will be examining areas of origin such as hydrothermal vents, mid-ocean ridges, and deep-sea
trenches and subduction zones.
Objectives
1. To determine how rocks are formed
2. To determine how the rock cycle functions in the ocean
3. To determine how types of matter can be converted
Materials
Rock Samples
Rock Identification Charts
Before Class
Go online and review the following video prepared by your teacher:
“Formation of rock types”
Answer the following questions:
1. What are igneous rocks associated with? (5pt)
2. What is a great example of where sedimentary rocks are formed? (5pt)
3. Besides heat, what else helps to transform metamorphic rocks? (5pt)
4. Suppose a lot of plankton skeletons settle, undisturbed on the seafloor for millions of years. What specific
rock is likely to form? (5pt)
Procedure
1. To start, you will need to acquire a rock sample and bring it to class. The rock should be the size of your
two fists, put together. This rock can be from anywhere, but try not to get the same rock as anyone else. You
will need to crack the rock at home, so that you can expose the inner surfaces. Find a rock, don’t buy one.
Your instructor will need to check and approve your rock sample to make sure that it is appropriate. (100pt)
Stamp of Approval:
2. You will need to identify your rock sample. Fill out the slots below. To the right, draw a color picture of
the rock: (20pt)
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
3. Now, you will need to identify 10 more rock samples, using the same procedure as above. Fill out the slots,
and draw a color picture for each: (10pt ea)
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Rock Type:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Drawing:
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Rock Type:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Drawing:
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Rock Type:
Drawing:
____________________
Rock Name:
____________________
Probable Origin (in the ocean):
____________________
Study Questions
1. The sea floor is formed via spreading at the mid-ocean ridges, associated with volcanic activity. What rock
type is the majority of the sea floor? (10pt)
2. There is a lot of pressure, heat, and shearing at subduction zones. What rock types might be formed in these
locations? (10pt)
3. Suppose that limestone sediment is compressed at one of these subduction zones. What rock would then
form? (10pt)
4. Suppose that same limestone in #3 is pushed further down under the adjoining plate, and interacts with
molten magma. What type of rock will it become then? (10pt)