Prentice Hall EARTH SCIENCE Tarbuck Lutgens 

Mountain Building CA CONTENT STANDARD 9b Chapter 11.1 Students know the principal natural hazards in different California regions and the geologic basis of those hazards. Who is Stan Hatfield and Ken Pinzke

Mountain Building CCSS.ELA-LITERACY.RST.9-10.1 Chapter 11.1 Mountain Building CCSS.ELA-LITERACY.RST.9-10.1 Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions. Who is Stan Hatfield and Ken Pinzke 3

Mountain Building Section Objectives Chapter 11.1 ~ Identify the factors that determine the strength of a rock and how it will deform. ~ Explain how rocks permanently deform ~ Distinguish among the types of stresses that affect rocks ~ List the three main types of folds and identify the main types of faults. Who is Stan Hatfield and Ken Pinzke

Mountain Building VOCABULARY Chapter 11.1 DEFORMATION STRESS STRAIN ANTICLINE SYNCLINE MONOCLINE NORMAL FAULT REVERSE FAULT THRUST FAULT STRIKE SLIP FAULT Who is Stan Hatfield and Ken Pinzke

Chapter 11.1 Mountain Building Who is Stan Hatfield and Ken Pinzke

Mountain Building TYPES OF FAULT DESCRIPTION Chapter 11.1 Normal fault READING STRATEGY TYPES OF FAULT DESCRIPTION Normal fault a. a hanging wall block moves down relative to the footwall block; high angle fault b. Reverse fault c. a hanging wall block moves up relative to the footwall block; high angle fault d. Thrust fault e. a hanging wall block moves up and over the footwall block; low angle fault f. Strike-slip fault g. movement is horizontal and parallel to the trend of the fault surface; usually consists of a zone of roughly parallel fractures Who is Stan Hatfield and Ken Pinzke

Stress is the force per unit area acting on a solid. #1 Strain is the change in shape or volume of a body of rock as a result of stress. #2 #5 #5

11.1 Rock Deformation Types of Stress  The three types of stresses that affect rocks are tensional stress, compressional stress, and shear stress. #7 Ex: stress of being confined in a small area Ex: stress of being pulled in opposite directons Ex: stress of being pushed inwards Ex: stress of being squeezed and twisted

Types of Stress when rocks are pulled in opposite directions Makes no sense without caption in book when rocks are squeezed or shortened when rocks are distorted

11.1 Rock Deformation Deformation is a general term that refers to all changes in the original shape and/or size of a rock body. #3  Factors that influence the strength of a rock and how it will deform include #4 * temperature * confining pressure * rock type * time. - Most crustal deformation occurs along plate margins.

11.1 Rock Deformation Factors Affecting Deformation  Temperature and Pressure Rocks deform permanently in two ways: brittle deformation and ductile deformation. - Brittle deformation is the fracturing of an object once its strength is exceeded. This occurs to rocks near the surface, where temperature and confining pressure is low. - At depth, Ductile deformation is a type of solid state flow that produces a change in the size and shape of an object without fracturing the object. It is strongly aided by high temp. and high confining pressure. #6a

11.1 Rock Deformation Factors Affecting Deformation  Rock Type Mineral composition and texture of a rock also greatly affect how it will deform. #6c Granitic from the continental crust and basaltic rocks from the oceanic crust are composed of minerals with strong internal molecular bonds usually fail by brittle fracture. Sedimentary rocks that are weakly cemented or metamorphic rocks that contain zones of weakness such as foliation will behave in a ductile manner under force. Examples include rock salt, gypsum, shale, limestone, schist and marble.

11.1 Rock Deformation Factors Affecting Deformation  Time Forces that are unable to deform rock when first applied may cause rock to flow if the force is maintained over a long period of time. For example, marble benches have been known to sag under their own weight over a span of 100 years or so. Small stresses applied overtime play an important role in rock deformation. #6b

Anticlines and Synclines Makes no sense without caption in book

11.1 Rock Deformation Folds  Anticlines #9 -series of wavelike ripples formed when sedimentary and igneous rocks are bent.  Anticlines #9 Anticlines are most commonly formed by the upfolding, or arching, of rock layers. The oldest rock layer in an anticline would be in the center of the fold.

11.1 Rock Deformation Folds  Synclines #10 -series of wavelike ripples formed when sedimentary and igneous rocks are bent.  Synclines #10 Synclines are linear downfolds in sedimentary strata. Synclines are often found in association with anticlines. The oldest rock layer in a syncline would be outside the fold.

Anticlines and Synclines Makes no sense without caption in book

11.1 Rock Deformation Folds  Monoclines #8 -series of wavelike ripples formed when sedimentary and igneous rocks are bent.  Monoclines #8 Monoclines are large step-like folds in otherwise horizontal sedimentary strata.

11.1 Rock Deformation Walls A. hanging wall block - the upper wall of an inclined fault inclined fault - a geological fault in which one side is above the other B. Footwall - the lower wall of an inclined fault

11.1 Rock Deformation Faults  Normal Faults Normal faults occur when the hanging wall block moves down relative to the footwall block. #11A https://www.youtube.com/watch?v=pjefNn9jQ5c

11.1 Rock Deformation Faults  Reverse Faults Reverse faults are faults in which the hanging wall block moves up relative to the footwall block. #11B https://www.youtube.com/watch?v=Xy0f_rubZJI

11.1 Rock Deformation Faults  Thrust Faults Thrust faults are reverse faults with dips less than 45o. #11C

11.1 Rock Deformation Faults  Strike-Slip Fault Strike-slip faults are faults in which the movement is horizontal and parallel to the trend, or strike, of the fault surface. #11D https://www.youtube.com/watch?v=4iddOA95xp4

Four Types of Faults Makes no sense without caption in book

Faults Joints  Joints Joints are fractures along which no appreciable movement has occurred. https://www.youtube.com/watch?v=AEkbkghWJeI

11.1 Quiz 1. What factors determine the strength of a rock? 2. In what ways do rocks deform? Explain the differences in these deformations. 3. Describe the different types of stress. 4. List the three types of folds. 5. Explain the direction of movement in the four types of faults.

ANSWERS 1. temperature, confining pressure, rock type, and time 2. brittle deformation which causes an object to fracture, and ductile deformation, which changes the shape and size of the object without fracturing it 3. Compressional stress is a force that com-presses, shortens, or squeezes a rock. Tensional stress is a force that pulls a rock apart, causing extension or lengthening of

Continuation: the rock. Shear stress is a force that causes a rock body to be distorted. 4. anticlines, synclines, and monoclines 5. In normal faults, the hanging wall moves down relative to the footwall and the movement is mainly vertical. In reverse and thrust faults, the hanging wall moves up relative to the footwall. In reverse faults the movement is mainly vertical; in thrust faults, the movement is mainly horizontal. Strike-slip faults move parallel to the trend of the fault, and the movement is mainly horizontal.

Mountain Building CA CONTENT STANDARD 9b Chapter 11.2 Mountain Building CA CONTENT STANDARD 9b Students know the principal natural hazards in different California regions and the geologic basis of those hazards. Who is Stan Hatfield and Ken Pinzke

Types of Mountains CCSS.ELA-LITERACY.RST.9-10.1 Chapter 11.2 Types of Mountains CCSS.ELA-LITERACY.RST.9-10.1 Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions. Who is Stan Hatfield and Ken Pinzke 32

SECTION OBJECTIVES Chapter 11.2 Explain how mountains are classified. Explain the difference between folded mountains and fault block mountains. Describe the formation of a dome. Who is Stan Hatfield and Ken Pinzke

VOCABULARY WORDS Chapter 11.2 OROGENESIS FOLDED MOUNTAIN FAULT BLOCK MOUNTAIN GRABEN HORST UPLIFTED MOUNTAIN Who is Stan Hatfield and Ken Pinzke

What are folded mountains? Mountains formed primarily by folding TYPES OF MOUNTAINS What are folded mountains? Mountains formed primarily by folding b. Formed by compressional stress c. Formed also by thrust-faulting What are fault block mountains? d. Formed from tensional stress e. Consist of elongated mountain ranges f. Separated by valleys formed by grabens What are are domes and basins? g. Formed by uplifting of basement rocks h. Produce circular or elongated structures i. Usually found isolated, not as part of mountain range Who is Stan Hatfield and Ken Pinzke 35

11.2 Types of Mountains Folded Mountains  Mountains are classified by the dominant processes that have formed them. Orogenesis is the collection of processes that produce a mountain belt #2.  Folded Mountains Mountains that are formed primarily by folding are called folded mountains #1. The major force that forms folded mountains is called the compressional force #3. Thrust faulting is also important in the formation of folded mountains, which are often called fold and thrust belts #4.

Folded Mountains Makes no sense without caption in book https://www.youtube.com/watch?v=PDrMH7RwupQ Examples of folded mountains include the Appalachian mountains, Northern Rocky Mountains and the Alps in Europe. #5

11.2 Types of Mountains Fault-Block Mountains  Large-scale normal faults are associated with structures called fault-block mountains. Fault-block mountains are formed as large blocks of crust are uplifted and tilted along normal faults. Grabens are formed by the downward displacement of fault-bounded blocks. Horsts are elongated, uplifted blocks of crust bounded by faults.

Fault-Block Mountains Grabens produce an elongated valley bordered by horsts. #8b The Basin and Range Province of Nevada, Utah and California are examples of fault block mountains. #8d #6 A B https://www.youtube.com/watch?v=BzPRfVgHbjM&list=PLPFIznnz2EsrAbEeyjuBvkFoKJ3tt8Rbp&index=2 Makes no sense without caption in book #7 Normal faulting occurs where tensional stresses cause the crust to be stretched. #8a

11.2 Types of Mountains Domes and Basins  When upwarping produces a circular or elongated structure, the feature is called a dome. #9 Uplifted mountains are circular or elongated structures formed by uplifting of the underlying basement rock. The Black Hills of Western South Dakota make up a large domed structure thought to be formed by upwarping. #10

11.2 Types of Mountains Domes and Basins The Black Hills of Western South Dakota make up a large domed structure thought to be formed by upwarping. #10

Domed Mountains Broad upwarping in basement rocks may deform the overlying cover of the sedimentary strata, generating large folds. The oldest rocks form the core in the dome. The youngest rocks are found near the center in a basin. The Black Hills of S. Dakota makeup a large domed structure. #11 The Black Hills of South Dakota contain exposed igneous and metamorphic rocks in the center of the dome. #12 Makes no sense without caption in book

11.2 Types of Mountains 1. Describe how mountains are classified. 2. List the major types of mountains. 3. What is a graben? In what type of mountains are grabens most commonly found? 4. What is the dominant type of stress associated with folded mountains?

Answers 1. Mountains are classified by the processes that are involved in forming them. 2. folded mountains, fault-block mountains, and uplifted or domed mountains 3. A graben is a block that is bounded by normal faults that has been down-dropped. Grabens are most commonly found in fault-block mountains. 4. compressional stress

Mountain Formation Section Objectives Chapter 11.3 Identify the type of mountains associated with convergent plate boundaries. Distinguish between mountains formed by ocean- ocean convergence and mountains formed by ocean- continental convergence. Identify the type of mountains associated with divergent plate boundaries. Explain how isostatic adjustment is involved in mountain formation. Who is Stan Hatfield and Ken Pinzke 45

Mountain Formation Vocabulary ◆ accretionary wedge ◆ accretion Chapter 11.3 Mountain Formation Vocabulary ◆ accretionary wedge ◆ accretion ◆ terrane ◆ isostasy ◆ isostatic adjustment Who is Stan Hatfield and Ken Pinzke 46

Mountain Formation Chapter 11.3 Mountain Formation Reading Strategy Mountain Formation A. Mountain Building at Convergent Boundaries 1. Ocean - Ocean Convergence 2. Continent – Continent Convergence 3. Ocean – Continental Convergence B. Mountain Building at Divergent Boundaries C. Non-Boundary Mountains D. Continental Accretion 1. Terranes 2. Mountains from Accretion E. Principles of Isostasy 1. Isostatic Adjustments for Mountains Who is Stan Hatfield and Ken Pinzke 47

11.3 Mountain Formation Mountain Building at Convergent Boundaries  Most mountain building occurs at convergent plate boundaries #1. Colliding plates #2 provide the compressional forces that fold, fault, and metamorphose the thick layers of sediments deposited at the edges of landmasses.

11.3 Mountain Formation Mountain Building at Convergent Boundaries  Ocean-Ocean Convergence Ocean-ocean convergence mainly produces volcanic mountains.  Ocean-Continental Convergence The types of mountains formed by ocean-continental convergence are volcanic mountains and folded mountains. #4 An accretionary wedge is the accumulation of different sedimentary and metamorphic rocks with some scraps of ocean crust.

Ocean-Ocean Convergence Makes no sense without caption in book The converging plates can lead to the growth of volcanic island arc on the ocean floor. Example of this is the Aleutian Islands of Alaska. It mainly produces volcanic mountains. #3

Ocean-Continental Convergence Makes no sense without caption in book

11.3 Mountain Formation Mountain Building at Convergent Boundaries  Continental-Continental Convergence At a convergent boundary between two plates carrying continental crust, a collision between the continental fragments will result and form folded mountains. #6

Continental-Continental Convergence Makes no sense without caption in book

11.3 Mountain Formation Mountain Building at Divergent Boundaries  The mountains that form along ocean ridges at divergent plate boundaries are fault-block type mountains. #7

Mountain Building by Continental Accretion #5 D - accretionary wedge C E – continental volcanic arc B Makes no sense without caption in book A

11.3 Mountain Formation Non-Boundary Mountains  Not all mountains are formed by plate boundaries. Some are formed by hot spots or regional extension or stretching.  Volcanic mountains are forming in locations of volcanic hot spots or volcanic activity. Many fault block mountains occur in areas that are undergoing regional extension or stretching. #8

11.3 Mountain Formation Continental Accretion  Accretion is a process that occurs when crustal fragments collide with and stay connected to a continental plate, causing them to get stuck to or embedded into the continent. #9  Terranes Terranes are any crustal fragments that have a geologic history distinct from that of the adjoining fragments. Terranes occur along the Pacific Coast.

Accretion in Western North America Makes no sense without caption in book

11.3 Mountain Formation Principles of Isostasy  Isostatic Adjustment for Mountains Isostasy is the concept that Earth’s crust is floating in gravitational balance upon the material of the mantle. Because of isostasy, deformed and thickened crust will undergo regional uplift both during mountain building and for a long period afterward. #10 Isostatic adjustment is the process of establishing a new level of gravitational equilibrium.

Isostatic Adjustment Makes no sense without caption in book

Isostatic Adjustment in Mountains Makes no sense without caption in book

Dangerous Mountain Roads Makes no sense without caption in book

11.3 Meeting the Standards 1. What types of mountains are associated with convergent plate boundaries? 2. What mountains are associated with divergent plate boundaries? 3. How is isostatic adjustment involved in mountain building? 4. How is accretion involved in mountain formation? Makes no sense without caption in book

Answers 1. mainly volcanic mountains 2. Fault-block mountains at ocean ridges are associated with divergent boundaries. 3. As the crust is thickened due to mountain building, the lithosphere will sink deeper into the mantle. But the lithosphere is less dense than the mantle, so the lithosphere will stand higher. To balance the added thickness, the crust will rise as a new level of gravitational equilibrium is reached. Makes no sense without caption in book

Answers 4. At a subduction zone, if an oceanic plate is carrying any island arcs or small continental fragments, they will be stuck to or embedded into the margin of the continental plate. This process of accretion deforms the continental plate and can form mountains. Makes no sense without caption in book