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17 Cards in this Set
- Front
- Back
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What is Diastrophism
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Any process that deforms or changes the earth's surface by movement or plates (plate tectonics)
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What is "elastic deformation"?
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When materials return to their original shape after a deforming pressure is removed.
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What is "plastic deformation"? How is this related to "elastic limit"?
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When a material does not return to its original shape after a deforming pressure is removed. This means that its elastic limit has been exceeded.
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What is one way that materials, including rocks, respond to pressure?
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no change
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What is "stress"?
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Force that tends to compress, pull apart, or deform a rock
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What are the 3 types of stresses that deform rock? Describe each.
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1. Compressive Stress- Caused when two plates move together or one plate pushing against a plate that is stationary (not moving)
2. Tensional Stress- when one plate moves away and the other does not move 3. Shear stress- when two plates slide past each other, or one plate slides past a stationary plate |
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What is "strain"? Describe 3 types
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Strain- a rock adjustment to stress
1. Elastic strain- rock units recover their original shape after stress is released. 2. Plastic strain- rock units are molded/bent and do not return to their original shape after stress is released 3. Fracture strain- rock units crack or break |
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On what 4 variables does the relationship between stress and strain depend. Describe each.
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1. Nature of rock- rocks are better able to with stand compression than pulling apart (or tensional) stress.
2. Temperature of rock- cold rocks are more likely to break than warm rocks. (Warm rocks tend to undergo plastic deformation). 3. How quickly the stress is applied over time (quick stress tends to break rock and slow stress results in plastic strain). 4. Confirming pressure on the rock (deeply buried rocks are under greater pressure and temperature, tend to undergo plastic strain while the rocks closer to the surface break more easily). |
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Where is sedimentary rock usually deposited, and in what structure?
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Sedimentary rock: usually deposited in flat, horizontal layers at the bottom of a body of water
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What are folds? How can they occur?
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Folds are bends in layered bedrock. They can occur from plastic strain
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Describe "anticlines" and synclines". Why are these folds not always visible at the Earth's surface?
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Anticlines are arch-shaped folds; synclines are trough-shaped folds. Anticlines are constantly being weathered into sediments; the sediments fill in the synclines
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What is a "fault"?
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Fault- break in a rock formation along which movement has occurred between rocks on either side
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What is a "normal fault"? Describe the two parts.
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Normal fault- one in which the hanging wall has moved downward relative to the footwall. The footwall is the upper stationary portion of the fault.
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What is an "earthquake"? What is the result of?
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Quaking, vibrating, or upheaval of the ground. It is the result of a sudden release of energy coming from stress on rock beneath the earth's surface. When it fractures, it produces seismic waves.
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How does "Elastic rebound" cause earthquakes?
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Stress builds along the entire fault as one plate attempts to move along the other. When the rock's elastic limitation is exceeded, the rock snaps into new positions
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What is the "focus"? What is the "epicenter"?
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Focus- the actual place where seismic waves originate beneath the Earth's surface
Epicenter- the point on the surface directly above the focus |
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What is a tsunami?
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Tsunami- large destructive ocean wave caused by an under sea earthquake, landslide, or volcano
Tsunamis do not break on shore and recede quickly. The water continues to rise for 5-10 minutes after breaking on shore |
