1. Chapter-11 Mountain Building
Notes

2. Section 11.1 “Where Mountains Form”
Objective – 1: Explain how some of earth’s 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

3. Section 11.1 “Where Mountains Form”
Objective – 1: Explain how some of earth’s 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

4. 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

5. Compare and contrast Active and Passive Continental Margins:
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;

6. 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.

7. Active continental margins: Passive margins:
Active continental margins are along continental/ocean boundaries located
at plate boundaries.

8. Chapter 11 Section 2
How Mountains Form:

9. 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.

10. 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

11. 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

13. 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.

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

15. Objective – 3: Explain how compression, tension, and shear stress deform rocks.
Draw a sketch of a compression, tension and shear stress:

16. 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

17. Objective – 4: Compare and Contrast Anticlines and Synclines

18. Objective – 4: Compare and Contrast Anticlines and Synclines

19. Objective – 5: Distinguish among the three major types of faults – normal, reverse, and strike-slip.

20. Objective – 5: Distinguish among the three major types of faults – normal, reverse, and strike-slip.

21. Objective – 5: Distinguish among the three major types of faults – normal, reverse, and strike-slip.

22. A strike-slip fault moves horizontally along a fault line.
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.

23. Chapter 11 Section 3
Types of Mountains

24. 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.

25. 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

26. Fault-block Mountains
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

27. 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

28. 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 earth’s 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.

29. 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
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

30. Mountains
End