Chapter 5 Review
Rocks and Minerals II

Name___________________

1. Write a definition in your own words for term

weathering

.

The process in which rocks break down into smaller pieces by chemical actions or by mechanical means (wind, water, or ice)

2. What is a sediment?

Smaller pieces of weathering of rock that are carried and deposited by wind, water, or ice.


3. What is deposition?

The laying down of sediment by the natural processes of wind, water, and ice.


4. Name the three ways that sedimentary rocks are formed.

Cementation, compaction and recrystallization


5. How does coal form?
Organic sedimentary rocks form from the build up and decay of plant and animal material. This usually forms in swamp regions in which there is an abundant supply of growing vegetation and low amounts of oxygen. The vegetation builds so quickly that new layers of vegetation bury the dead and decaying material very quickly. The bacteria that decay the vegetation need oxygen to survive. Because these decaying layers are buried so fast the bacteria use up what oxygen there is available and can not finish the decomposition of the vegetation. The overlaying layers become so heavy that they squeeze out the water and other compounds that aid in decay. This compressed vegetation forms coal.
6. What is the most common sedimentary rock?

Shale


7. Write three interesting facts about limestone.

Forms from calcium carbonate, Limestone caves form from ground water chemically breaking down the limestone and hollowing out a cave, stalagmites and stalactites form from the constant dripping of ground water saturated with calcium carbonate, marble forms form metamorphosed limestone.


8. What is the difference between

stalactites

and

stalagmites

?

Stalactites form from the ceiling down and stalagmites form from the ground up.


9-10. Compare and contrast

breccia

and

conglomerate

. (How are the alike and how are they different).

Breccia and conglomerate form from cementation of pebbles of various sizes. The difference is that breccia forms from angular pebbles and conglomerate forms from rounded pebbles.


11. What is a

metamorphic

rock?

Metamorphic rocks form from the intense heat and pressure that changes a preexisting rock.


12-14. What are the three main

agents

of metamorphism?

Temperature increases, increase in pressure, chemical changes


15-17. Define

Contact

,

Regional

, and

Dynamic

metamorphism.

Contact metamorphism occurs when magma comes into contact with preexisting rock, changing the rock.

Regional metamorphism occurs over a very large area. It is caused by large scale mountain building that puts terrific stress on existing rocks. This causes an increase in both heat and pressure that changes the rock.


Dynamic metamorphism also occurs because of mountain building but over a smaller area.


18. How does

marble

form?

Marble forms from the metamorphism of limestone or dolomite.




19-22. Name the four eras of geologic time from the oldest era to the present era.

Precambrian, Paleozoic, Mesozoic, Cenozoic


23. Compare and contrast the terms

biological

and

physical

changes.

Biological changes are changes in species of plants and animals. Physical changes are large scale geological or climatic changes.


24-35. Describe the climate, the land, and the dominant plant or animal of each of the four eras of geologic time.

Precambrian-


Climate

-Very hot early on but cold near the end of the Precambrian time.

Land-

Large land mass located far south near the South Pole.

Dominant plant and animal-

Very few fossils have been found. Very simple plants such as algae have been found.



Paleozoic

-
Climate-

Cold at the start of the Paleozoic but very warm at the end of the era.


Land-

The continents were one large land mass that was located near the South Pole. The continent slowly moved north and the climate warmed up.


Dominant plant and animal-

Simple invertebrates at the start of the era. The era is known as the "Age of Fish". The dominant creatures were still lived in the sea. Simple land plants and animals were beginning to evolve.


Mesozoic


Climate-

Very warm with the oceans still high.

Land-Pangaea

was separating into the seven continents. At the end of the Mesozoic the Rocky Mountains were being built.


Dominant plant and animal-

Reptiles were everywhere. The dinosaurs dominated the land.


Cenozoic

-
Climate-

The world's climate was cooling down and the ocean levels were lowering as the ice packs were growing near the poles.


Land-

The inland seas were drying up and the continents were similar to how they are today.


Dominant plant and animal-

The mammals were taking over as the dinosaurs died out. This is the era that we are living in today




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