Rock Cycle _Review Study Guide
1. A series of processes that slowly change rocks from one kind to another is referred to
as the rock cycle.
2. Is the following sentence true or false? The rock cycle is produced by forces inside the
Earth and at the surface. true
Fill in Sedimentary, Igneous or Metamorphic in each box.
6. All rocks follow the same pathway through the rock cycle is a false statement. Why?
Rocks can change to any kind of rock at any given time if the conditions are right.
7. How does granite change into sandstone?
Granite is weathered into sediments. The sediments are compacted or cemented together to form
sandstone.
8. How does sandstone change into quartzite?
Sandstone is covered by layers of sediment. The sediments are piled on top of other rock causing
great pressure. As they are pushed down into Earth’s crust more heat is applied. The heat and
pressure changes sandstone to quartzite.
9. Define igneous rocks.
A rock that forms when magma or lava cools and hardens.
10. Give examples of 2 intrusive rocks.
Gabbro, granite, diorite
11. Give examples of 2 extrusive rocks.
Pumice, obsidian, basalt, rhyolite, andesite
12. Give examples of 2 rocks that are high in silica.
Granite, andesite, quartz
13. Give examples of 2 rocks that are low in silica.
Basalt, gabbro
14. Define sedimentary rock.
Rock that forms from weathered materials that have compacted or cemented together.
15. How are clastic rocks formed?
Clastic rocks are made of sediments that are weathered, transported, and deposited in layers.
16. Give an example of a large grain clastic rock.
Conglomerate or breccia
17. Give an example of a med. Grain clastic rock.
sandstone
18. Give an example of a small grain clastic rock.
Siltstone or shale
19. How are chemical sedimentary rocks formed?
Chemical rocks are formed from minerals that were dissolved in water, came out of solution, and
then were deposited.
20. Give 2 examples of chemical rocks.
Chalk, limestone, halite, gypsum
21. How are organic sedimentary rocks formed?
Organic sedimentary rock forms when dead plant or animal material compacts with other
sediments over long periods of time.
22. Give 2 examples of organic rocks.
Coal, chert, chalk
23. Define Metamorphic rock.
A rock that forms when another rock is under great heat and pressure.
24. What does foliated mean?
Foliated rocks have layers or bands that can be seen.
25. Give an example of a foliated rock.
Slate, schist, gneiss
Rock can follow many different pathways through the rock cycle. Here are two examples:
Pathway 1
Between New Zealand and South America, at the bottom of the Pacific Ocean, Molten material
from the mantle rises through the crust. As the material comes into contact with the very cold
ocean water, it cools quickly to become rock. Over time this rock ever so slowly moves across
the ocean floor. About 200 million years later, the rock is pushed downwards. As the rock moves
downward, it experiences great amounts of heat and pressure.
Pathway 2
Deep underground, a new rock forms as heat and pressure change its crystals and cause its
grains to become foliated. Over millions of years, this rock is uplifted to become part of a
mountain. Then, layers of rock above the foliated rock wear away, until it becomes exposed at
the surface. Destructive forces wear it down, and its fragments are carried away by a river’s
swift-flowing water. Eventually, these fragments flow into the ocean. Ocean water carries the
rock fragments away from the river and they are deposited on a beach. Over time, more and
more sediment is deposited there, until the fragments that came from the foliated rock become
cemented into a new rock. Then more and more rock forms above this rock, until the heat and
pressure change its crystals and cause its grains to become foliated.
26. Which major group or groups of rocks are involved in the description of Pathway 1?
Igneous and metamorphic
27. Make a flowchart that describes what occurs in pathway 1
Magma-cooling and hardening-igneous rock-heat and pressure-metamorphic rock
28. Which major group or groups of rocks are involved in the description of pathway 2?
Metamorphic, sedimentary
29. Make a flowchart that describes what occurs in Pathway 2.
Metamorphic rock-weathered and deposited-sedimentary rock- heat and pressuremetamorphic rock
30. Write a description of another pathway through the rock cycle. In your description, tell
how igneous rock changes to metamorphic rock, which then changes to sedimentary
rock.
Igneous rock is exposed to heat and pressure, changing it to metamorphic rock. Metamorphic
rock is weathered into sediments. The sediments are cemented or compacted to form
sedimentary rock.
31. How are igneous rocks formed?
Magma or lava cools and hardens into a solid
32. How are sedimentary rocks formed?
Weathering and erosion of rocks; cementation or compaction of the sediments to form new rock
33. How are metamorphic rocks formed?
Rock is exposed to great amounts of heat and pressure transforming it to a metamorphic rock.
34 Where are intrusive igneous rocks formed? What size of crystals will they have?
Inside Earth’s crust; larger crystals because they cool slowly
35 Where are extrusive igneous rocks formed? What size of crystals will they have?
On Earth’s surface; small or no crystals because they cool quickly
36 What are clastic rocks?
Rocks are made by sediment that was weathered, transported, and deposited.
37. What are foliations in metamorphic rocks?
Visible bands or layers
38 How do chemical sedimentary rocks form?
Minerals dissolve in water and come out of solution (evaporation)
39. How do organic sedimentary rocks form?
Compaction and layering of sediment with dead plant or animal material
40 Why would you tend to find lots of fossils in sedimentary rocks? Why not in other
rocks?
They form in layers of sediment; igneous forms from magma/lava that would melt the dead
remains—metamorphic form deep in the Earth where we don’t find dead organisms
41. Why would a metamorphic rock show signs of great stress?
Metamorphic rocks form under great pressure
42. List and explain the 6 characteristics of minerals that can be used for identifying
minerals in a lab setting:
a. hardness
d. crystalline structure
b. fracture/cleavage
e. chemical composition
c.
f.
streak color
density
43 What hardness do the following objects have?
fingernail
glass
copper penny
2.5
5.5
3
steel file/nail
6.5-7.5