Chapter-11%20Mountain%20Building

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Chapter-11 Mountain Building

• Notes

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Objective 1 Explain how some of earths major
mountain belts formed.

• Section 11.1 Where Mountains Form
• Mountain A large mass of rock that rises a
  great distance above its base
• Mountain Belts
• Mountain ranges that follow convergent plate
  boundaries
• NA Cordillera mountain belt that runs down the
  western side of NA from Alaska to Mexico
• Appalachian Mountains do not lie along a plate
  boundary

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Objective 1 Explain how some of earths major
mountain belts formed.

• Section 11.1 Where Mountains Form
• Some mountain belts are formed along active
  continental margins by the subducted plate
  pushing up the overriding plate
• Therefore most mountain ranges are located along
  plate boundaries

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Objective 2 Compare and contrast active and
passive continental margins.

• Define
• Continental margin is a boundary between
  continental crust and oceanic crust
• Passive continental margin stable areas that are
  not located near plate boundaries

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Objective 2 Compare and contrast active and
passive continental margins.

• Compare and contrast Active and Passive
  Continental Margins
• Active located along plate boundaries both lie
  along continental margins
• Passive Not located along any plate boundaries
  consists of mainly marine sediments weathered
  rock

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Objective 2 Compare and contrast active and
passive continental margins.

• Looking at the Plate Boundary Map on pages 712
  713, there are a number of Active and Passive
  continental margins
• Active continental margins include west coast of
  South America west coast of North America east
  coast of Japan west coast of Indonesia
• Passive continental margins include east coast of
  N America east coast of S America west coast of
  Africa south east coast of Africa etc.

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Active continental margins Passive margins
Active continental margins are along
continental/ocean boundaries located at plate
boundaries.
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Chapter 11 Section 2

• How Mountains Form

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Objective 3 Explain how compression, tension,
and shear stress deform rocks.

• Types of Stress
• Forces involved in plate interactions produce
  features such as folds and faults.
• Folded Mountains
• Two plates collide, can cause folding of rock
• Before two continents can collide the ocean basin
  between them must close Subduction
• Himalayas formed by the ocean basin between India
  and Tibet closed due to Subduction.

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Objective 3 Explain how compression, tension,
and shear stress deform rocks.

• Dome Mountains
• Nearly circular folded mountain
• Individual isolated structures
• Plutonic dome Mountain
• Formed by overlaying crustal rock pushed up by an
  igneous intrusion such as a laccolith.
• Center rocks (igneous) are younger than the outer
  rocks
• Tectonic Dome Mountains
• Result of uplifting forces that arch rock layers
  upward
• All the rocks were present before the uplift
  occurred

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Objective 3 Explain how compression, tension,
and shear stress deform rocks.

• Fault-block Mountains
• The crust is stretched (tensional forces) and
  normal faults are created
• Whole blocks are pushed up
• Horst and Grabens
• Tensional stress and normal faulting cause these
• Between tensional faulting, grabens (large
  blocks) have dropped
• When large blocks are thrust upward, between
  normal faults, it is called a Horst

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Objective 3 Explain how compression, tension,
and shear stress deform rocks.

• Define
• Anticline an up-fold in rock layers
• Syncline down-fold in rock layers
• Stress Types
• Compression rock layers are being squeezed
  together
• Tension rock layers are being stretched or
  pulled apart
• Shear rock layers are being pushed in two
  different, opposite directions.

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Objective 3 Explain how compression, tension,
and shear stress deform rocks.
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Objective 3 Explain how compression, tension,
and shear stress deform rocks.

• Draw a sketch of a compression, tension and shear
  stress

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Objective 4 Compare and Contrast Anticlines
and Synclines

• An anticline is an up-fold of the rock layers
• A Syncline is a is a down-fold of the rock layers
• Both are usually caused by compressional forces

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Objective 4 Compare and Contrast Anticlines
and Synclines
Syncline
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Objective 4 Compare and Contrast Anticlines
and Synclines
Anticline
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Objective 5 Distinguish among the three major
types of faults normal, reverse, and
strike-slip.
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Objective 5 Distinguish among the three major
types of faults normal, reverse, and
strike-slip.
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Objective 5 Distinguish among the three major
types of faults normal, reverse, and
strike-slip.
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Objective 5 Distinguish among the three major
types of faults normal, reverse, and
strike-slip.

• The difference between a normal fault and a
  reverse fault are the stresses that cause them
• Reverse fault is caused by compressional forces
• Normal fault is caused by tensional forces
• A strike-slip fault moves horizontally along a
  fault line.

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Chapter 11 Section 3

• Types of Mountains

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Objective 6 Classify mountain ranges by their
most prominent features.

• Folded Mountains
• Two plates collide, can cause folding of rock
  through compressional stress
• Before two continents can collide the ocean basin
  between them must close Subduction
• Himalayas formed by the ocean basin between India
  and Tibet closed due to Subduction.

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Objective 6 Classify mountain ranges by their
most prominent features.

• Dome Mountains
• Nearly circular folded mountain
• Individual isolated structures
• Plutonic dome Mountain
• Formed by overlaying crustal rock pushed up by an
  igneous intrusion such as a laccolith.
• Center rocks (igneous) are younger than the outer
  rocks
• Tectonic Dome Mountains
• Result of uplifting forces that arch rock layers
  upward
• All the rocks were present before the uplift
  occurred

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Objective 6 Classify mountain ranges by their
most prominent features.

• Fault-block Mountains
• The crust is stretched (tensional forces) and
  normal faults are created
• Whole blocks are pushed up

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Objective 6 Classify mountain ranges by their
most prominent features.

• Horst and Grabens
• Tensional stress and normal faulting cause these
• Between tensional faulting, Grabens (large
  blocks) have dropped
• When large blocks are thrust upward, between
  normal faults, it is called a Horst

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Objective 6 Classify mountain ranges by their
most prominent features.

• When two land masses collide, they usually
  crumple and form folded mountains.
• Volcanic mountains tend to form on the overriding
  plate at a Subduction zone.
• Fault Block Mountains form when the earths crust
  is slowly up-lifted.
• The uplift has caused the crust to stretch and
  crack, forming normal faults along the surface.
  As uplift continues, whole blocks of crust have
  been pushed up.

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Objective 7 Compare and contrast folded
mountains, dome mountains, volcanic mountains,
and fault-block mountains.
Type of Crust Where are they found Uplift Mechanism Examples of
Plutonic Dome Mountain Crustal and igneous rock inland Isolated structures in flat lying sedimentary rocks Igneous intrusion Border of the Colorado Rockies
Tectonic Dome Mountain Crustal rock inland Isolated structures in flat lying sedimentary rocks Uplift force Adirondack Mtns.
Folded Mountain Continental Crust Continental continental plate boundaries Continued plate movement Alps, Appalachians
Volcanic Mountain Continental, near Subduction boundary Subduction boundary Volcanic material (magma, ash, etc.) Cascades
Fault-block Mountain Continental Western US Uplift forces Sierra Nevada Mountains
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Mountains

• End