1a. Define: Catastrophism
The view that most of earth’s geological features are the result of large-scale catastrophes such as floods, volcanic eruptions, etc.
1b. Define: Uniformitarianism
The view that most of earth’s geological features are the result of slow, gradual processes that have been at work for millions or even billions of years.
1c. Define: Humus
The decayed remains of once-living creatures
1d. Define: Minerals
Inorganic crystalline substances found naturally in the earth
1e. Define: Weathering
The process by which rocks are broken down to form sediments
1f. Define: Erosion
The process by which rock and soil are broken down and transported away
1g. Define: Unconformity
A surface of erosion that separates one layer of rock from another
- Which hypothesis (uniformitarianism or catastrophism) requires that the earth be billions of years old?
The uniformitarian hypothesis
- What are three basic types of rocks?
igneous, metamorphic, and sedimentary
- How is each type of rock mentioned in #3 formed?
Igneous rock is the result of molten rock that cools and solidifies. Sedimentary rock is formed when sediments fuse together. Metamorphic rock is formed when either sedimentary or igneous rocks change, usually as a result of temperature or pressure.
- What agent is responsible for laying down most of the sedimentary rock we see today?
water
- A rock in the desert is constantly bombarded by bits of sand that are carried on the wind. Sometimes the sand hits the rock so hard that tiny chips of the rock are broken off. As time goes on, the constant beating of the sand on the rock wears the rock down, and it gets much smaller. Has the rock experienced physical or chemical weathering?
physical weathering
- When limestone is exposed to weakly acidic water, it breaks down, forming a gas in the process. Is this chemical or physical weathering?
chemical weathering
- A geologist is comparing the erosion that occurs as a result of two different rivers. The first river flows quickly while the second flows slowly. Which river do you expect to cause the most erosion?
quickly-flowing water
- Two hillsides in the same community experience a very heavy rain. The first hillside is covered with grass and flowers, while the second is mostly bare. Which hillside will experience the most erosion?
the barren hillside
- What causes a river to form a delta?
the river deposits many of the sediments it carries there
- What kind of water is responsible for eroding underground caverns?
groundwater
- What is the difference between a stalactite and a stalagmite?
Stalactites form on the ceiling of a cavern, while stalagmites form on the floor of a cavern.
- What causes stalactites and stalagmites to form?
Stalactites and stalagmites are formed when groundwater seeps through the ceiling of a cavern. As the drop forms and falls to the floor of the cavern, it might deposit sediments on the ceiling or flow. As those sediments pile up, stalactites and stalagmites are formed.
- (see page 158) Which letter identifies metamorphic rock?
C
- (see page 158) Which 2 letters identify igneous rock?
A and E
- (see page 158) Which letter identifies sedimentary rock?
D
- (see page 158) Which letter identifies an angular unconformity?
B
- (see page 158) Which letter identifies an intrusion?
E
