Igneous, Sedimentary, Metamorphic Rocks
and
The Rock Cycle
The earth is an ever-changing dynamic planet. As one investigates the various rock types
making up the earth, it is clear that rocks vary in both textural and compositional characteristics. Earth
processes continually produce new rock through volcanic activity, the breakdown, transportation, as
well as deposition of pre-existing rock, and the subjection of pre-existing rock to varying pressures and
temperatures caused by tectonic forces. These processes define the rock cycle. Wherever one goes on
the earth’s surface, the rock cycle can be observed in continual action. If the earth’s internal processes
had ceased to continue, the external processes, exacerbated by gravity, would have long ago leveled the
continents, and the resulting sediments would have been deposited on the sea floor. In other words, the
dynamics of earth would be at rest or in a state of equilibrium. Yet, this is not the case. The rock cycle
clearly demonstrates that internal and external forces on the earth are alive and well, constantly
‘battling” each other. The result is a state of non-equilibrium which results in an ever-changing earth
surface.
Lab Objectives:

Determine the meaning of the rock cycle and what conditions are necessary to form igneous,
sedimentary, and metamorphic rocks.

Identify the names of common rock forming processes and how textural/compositional
characteristics are associated with the various geologic processes

Determine that the rock cycle is an open system that interacts with various other open systems
within the geosphere and how the rock cycle contributes to positive and negative feedback
mechanisms

Infer how specific hand samples representing all three rock groups have formed in relation to the
rock cycle
Rock Review:
In your own words, briefly explain how each rock group forms.
Igneous rocks:
Sedimentary rocks:
Metamorphic rocks:
Part A – Learning the Rock Cycle
Below is a diagram depicting the rock cycle. Complete the following:

Use the terms provided at the bottom of the page and fill in the various blanks to make the rock
cycle complete. On a separate piece of paper, define each term as it relates to the rock cycle.

Describe the geologic environment that results in igneous, sedimentary, and metamorphic rock
types.

Choose three different colors (use colored pencils), and shade in the regions that represent
igneous, sedimentary, and metamorphic rock environments on the rock cycle below.
weathering
metamorphic rocks
deposition
crystallization
sediment
transportation
sedimentary rocks
metamorphism
consolidation
igneous rocks (extrusive)
igneous rocks (intrusive)
sedimentary rock cycle
magma
melting
lithification
Part B- The Rock Cycle in Action
The diagram below demonstrates an ocean to continent plate convergent boundary where the oceanic plate
(A) is subducting beneath the continental plate (B). Complete the table below using the rock specimens in
the rock ID box, and describe each geologic environment associated with the rock cycle in Part A.
3
5
4
A
2
1
B
Circle
number
1
2
3
4
5
Geologic
Environment
Rock
Texture
Rock’s Chemical
Composition
Rock Name
Part C
The Rock Cycle Critical Thinking Questions
1. Why is the rock cycle considered an open system?
2. Describe other earth open systems that are related to processes within the rock cycle.
3. Where would you identify positive and negative feedback mechanisms within the rock cycle?
Does the rock cycle ever achieve equilibrium or maintain balance? Why or why not?
4. Do you consider the rock cycle important to the existence of the human species? Why or why
not?
5. Describe three observations you have had regarding some aspect of the rock cycle.
6. Without looking at a picture of the rock cycle, draw your own rock cycle, and include at least two
rock types for each rock group.
Part D
Rock Cycle Crossword Puzzle
Across
5. compaction and cementation
6. molten rock
10. volcanic rock
12. loose, unconsolidated particles
13. evaporated or precipitated sedimentary rock
14. plutonic rock
15. light-colored igneous composition
17. a foliated metamorphic rock consisting of alternating bands of dark and light minerals
18. your instructor's name
20. the laying down of sediment
21. sedimentary rock composed of inorganic particles
23. factors that promote change in a process
Down
1. rocks produced by weathering processes
2. geologic processes that form new rock, modify rock, transport rock, and break rock down
3. phaneritic rock high in SiO2
4. rocks formed as the result of pressure and temperature
5. a sedimentary rock consisting of calcite
7. the wearing away and transport of loosened particles
8. factors that resist change within a process
9. the physical and chemical breakdown of rock
11. aphanitic rock high in Fe and Mg
16. dark-colored igneous composition
19. sedimentary rock composed of organic material
22. rocks produced by solidifying magma