Download - 3.2 the results of stress
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The Results of Stress...
Mr. Silva
Objective
• Students will be able to identify and describe two types of rock deformation and explain the difference between them.
• Students will be able to demonstrate three types of faults by acting them out using their backpack.
The Results of Stress
• High pressure and temperatures caused by stress in the crust generally deform rocks.
• When stress is applied slowly, the deformed rock will return to its original shape.
• In extreme stress, rock becomes so deformed it may bend, tilt or break.
Folding
• When rocks respond to stress by becoming permanently deformed without breaking it is called folding. –Folds vary in size–There are 3 general types of folds.
3 General Types of Folds
• Anticline:
Upfolding or arching in which the oldest layer is in the center of the of the fold
Oldest layer of rock
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Anticline
3 General Types of Folds
• Syncline:
is a linear downfold in which the youngest layer is in the center
Youngest layer of rock
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Syncline
3 General Types of Folds
• Monocline:
is a step-like fold in which both limbs remain horizontal or vertical.
Different layers remaining vertical
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Monocline
Faulting • When rocks break due to stress instead of
fold.– Joint: no movement in the rocks along either
side of a break. – Fault: when rocks do move– Fault plane: surface of a fault where any motion
occurs– Hanging wall: rock above the fault plane of a
nonvertical fault– Footwall: rock below the fault plane of a
nonvertical fault
3 Types of faults• Normal fault: hanging wall moves down
relative to the footwall along divergent boundary
• Reverse fault: compression causes the hanging wall to move up relative to the footwall
• Thrust fault: fault plane is a low angle or nearly horizontal & hanging wall is pushed up over rock
• Strike-slip fault: rock on either side of the fault plane slides horizontally at transform boundaries
Mountain Formation
• Mountain Range: a group of adjacent mountains with the same general shape and structure.
Mount Everest
Himalaya Mountains
Mountain Formation
• Mountain System: a group of adjacent mountain ranges.
Great Smoky Mountains
Green Mountains
Appalachian Mountains
Mountain Formation
• Mountain Belts: the largest mountain system are part of two still larger systems.
Eurasian- Melanesian
mountain belt
Circum-Pacific mountain belt
Plate Tectonics and Mountains
• Both circum-Pacific mountain belt and the Eurasian- Melanesian mountain belt are located along convergent plate boundaries.
• Evidence that most mountains are formed from plate collisions.
• Ding Ding: Ding Ding: Convergent Plate Convergent Plate Boundaries build Boundaries build mountains!!!mountains!!!
Collision between Continental and Oceanic Crust
• What do we know happens when continental and oceanic crust collide?
• What do we know happens when crust overlap each other? What can happen?
• This will cause large scale deformation.
Continental Continental Volcanic Arcs!!!Volcanic Arcs!!!
Collision between Continental and Oceanic Crust
Collision between Oceanic and Oceanic Crust
• One plate usually submerges below the other and will cause a volcanic island arc.
Mariana Island in the North Pacific Ocean
Collision between Oceanic and Oceanic Crust
Collisions Between Continents
• Mountains can also form when two continents collide.
Collisions Between Continents
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Review
• What is folding? What type of deformation?
• Name three folds...
• What is faulting? What type of deformation?
• Name four faults...
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Rock deformed without breaking...Ductile
Anticline, Syncline, Monocline
Rock deformed by breaking...Brittle
Normal, Reverse, thrust, and Strike-Slip
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Review
• What boundary are most mountains formed?
• What boundary do strike-slip faults occur?
• What convergent plate boundary are the tallest mountains formed?
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Convergent Plate Boundaries
Transform Fault Boundaries
Continental-Continental Convergent Plate Boundaries