Mountains Chapter 16 - Belmont ESC11esc11.weebly.com/uploads/5/9/3/7/593742/_web_-_chapter16.pdf ·...
Transcript of Mountains Chapter 16 - Belmont ESC11esc11.weebly.com/uploads/5/9/3/7/593742/_web_-_chapter16.pdf ·...
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Chapter 16…what’s the connection?
Mountains and Plate Tectonics…
Mountain Building
Most crustal deformation occurs along plate margins.
Passive Margin
Active Margin
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Factors Affecting Deformation
Mountain Building
includes temperature, confining pressure, rock type, and time.
• Stress is the force per unit area acting on a solid.
• Strain is the change in shape or volume of a body of rock as a result of stress.
• Deformation - all changes in the original shape and/or size of a rock body.
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Types of Stress
Rock Deformation
The three types of stresses are:
tensional stress (pulling apart)compressional stress (pushing together)shearing stress (tearing apart)
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Types of Stress
tensional stress
compressional stress
shearing stress
Folds
Rock Deformation
Anticlines• Anticlines are most commonly formed by the
upfolding, or arching, of rock layers.Synclines
Monoclines• Monoclines are large step-like folds in
otherwise horizontal sedimentary strata.
• Synclines are linear downfolds in sedimentary strata.
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Anticlines and Synclines
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syncline anticline
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Monoclines
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monocline
Faults
Rock Deformation
Normal Faults• Normal faults occur when the hanging wall block
moves down relative to the footwall block.Reverse Faults and Thrust Faults• Reverse faults are faults in which the hanging
wall block moves up relative to the footwall block.• Thrust faults are reverse faults with dips less
than 45o.
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Faults
Rock Deformation
Joints• Joints are fractures along which no appreciable
movement has occurred.
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.
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Four Types of Faults
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Joints
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Types of Mountains
Mountains are classified by the dominant processes that have formed them.
Orogenesis or Orogeny is the collection of processes that result in the forming of mountains.
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Types of Mountains
A. Fold & Thrust Mountains
B. Dome Mountains
C. Fault Block Mountains
D. Volcanic Mountains
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(see Chapter 14 notes)
A. Folded Mountains
Types of Mountains
Mountains that are formed primarily by folding are called folded mountains.
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Folded Mountains
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B. Domes and Basins
Types of Mountains
When upwarping produces a circular or elongated structure, the feature is called a dome.• Uplifted mountains are circular or
elongated structures formed by uplifting of the underlying basement rock.
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Domed Mountains
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C. Fault-Block Mountains
Types of 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.
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Fault-Block Mountains
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Fault-Block Mountains
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D. Volcanic Mountains
Types of Mountains
Mountains that are formed primarily by eruptions and lava flows. See Chapter 14 notes for details.
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Mountain Building at Convergent Boundaries
Mountain Formation
Most mountain building occurs at convergent plate boundaries.Colliding plates provide the compressional forces that fold, fault, and metamorphose the thick layers of sediments deposited at the edges of landmasses.
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Mountain Building at ConvergentBoundaries
Mountain Formation
Ocean-Ocean Convergence• mainly produces volcanic mountains.
Ocean-Continent Convergence• volcanic mountains and folded mountains.
Continent-Continent Convergence• forms folded mountains.
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Ocean-Ocean Convergence
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Ocean-Continent Convergence
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Continent-Continent Convergence
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Mountain Building at DivergentBoundaries
Mountain Formation
The mountains that form along ocean ridges at divergent plate boundaries are fault-block mountains.
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Continental Accretion
Mountain Formation
Terranes• Terranes are any crustal fragments that
have a geologic history distinct from that of the adjoining fragments.
Accretion is a process that occurs when crustal fragments collide with and stay connected to a continental plate.
• Terranes occur along the Pacific Coast.
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Continental Accretion
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Accretion in Western North America
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Exercise 7
Folds and Faults!Complete Worksheet.
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Plate Tectonics Summary
Complete the following slides.(You have 5 minutes!)
Plate Tectonics Summary (1)
• The Earth is made up of 3 main layers (core, mantle, crust)
• Tectonic plates move slowly around the globe
• Plates are made of crust and upper mantle (lithosphere)
• Convection in the mantle (asthenosphere) moves the plates
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Plate Tectonics Summary (2)
• There are 2 types of plates (continental & oceanic)
• There are 3 types of plate boundaries (converging or subduction, diverging, sliding or transform)
• Volcanoes, Earthquakes and Mountain Building are closely linked to the margins of the tectonic plates
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Plate Tectonics Summary (3)
• There are 3 main types of volcanoes (shield, cinder, composite or stratovolcano)
• Volcanic activity includes rift eruptions, calderas, formation of plutons
• There are 2 main types of lava (felsic & mafic)
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Plate Tectonics Summary (4)
• There are 2 main types of seismic waves (surface & body)
• There are 2 main types of body waves (P & S)
• There are 4 main types of mountains(folded, fault block, dome and volcanic)
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UNIT TEST - Chapters 13-16
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Assignments:Chapter 13 – Plate Tectonics Notes & Vocab √Chapter 14 – Plate Tectonics & Volcanoes Notes & Vocab √Chapter 15 – Plate Tectonics & Earthquakes Notes & Vocab √Chapter 16 – Plate Tectonics & Mountain Building Notes & Vocab √
For Review and Test Prep:Go to esc11.weebly.com
• Flashcard Library (home page)• volcano photo review• link to practice quizzes and review PowerPoints• Quizlab – Chapters 13-16 Practice Test