1. Warm Up 12/3
The type of deformation in which the object permanently changes size and shape without fracturing is called ____.
a. stress deformation c. brittle deformation
b. elastic deformation d. ductile deformation
Folding is usually the result of ____.
a. tensional stresses c. shear stresses
b. compressional stresses d. faulting
Which of the following combinations should favor folding rather than faulting?
a. high temperature and high confining pressure
b. high confining pressure and low temperature
c. low confining pressure and low temperature
d. high temperature and low confining pressure
Answers: 1) d. 2) b. 3) a.

2. Types of Mountains
Chapter 11, Section 2

3. Mountains
Orogenesis – the collection of processes that produce a mountain belt
Mountains are classified by the dominant processes that have formed them.

4. Major Physiographic Provinces of the U.S.

5. Landforms of the U.S.

6. Folded Mountains
Mountains that have formed primarily by folding are called folded mountains
Compressional stresses are the major force that forms folded mountains
Thrust faulting is also a major component in folded mountains, which are often called fold-and-thrust belts
Examples: the Appalachians, the northern Rocky Mountains, and the Alps

7. Folded Mountains

8. Fault-Block Mountains
Large-scale normal faults are associated with structures called fault-block mountains
The mountains form as large blocks of crust are uplifted and tilted along normal faults
As the crust is stretched, a block called a graben, which is bounded by normal faults, drops down
Grabens produce an elongated valley bordered by relatively uplifted structures called horsts
Examples: Teton Range (Wyoming), Sierra Nevada, and the Basin and Range Province

9. Grabens and Horsts

10. Sierra Nevada Mountains

11. Proposal for Formation of the Basin and Range Province

12. Basin and Range Province

13. Concept Check What is a horst?
A horst is an uplifted block bounded by normal faults.

14. Domes and Basins
Broad upwarping in basement rock may deform the overlying cover of sedimentary strata
When upwarping produces a circular or elongated structure, the feature is called a dome
The oldest rocks of a dome form the core of the mountains
Downwarped structures having a circular shape are called basins
Large basins usually contain sedimentary beds sloping at low angles, the basins are usually identified by the age of the rocks composing them (youngest form the center)

15. Black Hills – Domed Mountains

16. Black Hills, South Dakota

17. Michigan Basin

18. Concept Check Where are the oldest rocks found in a dome?
In the center or core of the dome.

19. Assignment Read Chapter 11, Section 2 (pg. 314-316)
Do Chapter 11 Assessment #1-36 (pg )
For Section 2: Do #’s 3, 14, 15, 22, & 30