Chapter-11 Mountain Building Notes. Objective – 1: Explain how some of earth’s major mountain belts formed. Section 11.1 “Where Mountains Form” –Mountain.

Chapter-11 Mountain Chapter-11 Mountain BuildingBuilding

NotesNotes

Objective – 1: Explain how some of earth’s major mountain Objective – 1: Explain how some of earth’s major mountain belts formed.belts formed.

Section 11.1 “Where Mountains Form”Section 11.1 “Where Mountains Form”– Mountain – A large mass of rock that rises a Mountain – A large mass of rock that rises a

great distance above its basegreat distance above its base– Mountain Belts: Mountain Belts:

Mountain ranges that follow Mountain ranges that follow convergent plate convergent plate boundariesboundaries

NA Cordillera – mountain belt that runs down the NA Cordillera – mountain belt that runs down the western side of NA from Alaska to Mexicowestern side of NA from Alaska to Mexico

Appalachian Mountains do not lie along a plate Appalachian Mountains do not lie along a plate boundaryboundary

Objective – 1: Explain how some of earth’s major Objective – 1: Explain how some of earth’s major mountain belts formed.mountain belts formed.

Section 11.1 “Where Mountains Section 11.1 “Where Mountains Form”Form”– Some mountain belts are formed along Some mountain belts are formed along

active continental margins by the active continental margins by the subducted plate pushing up the subducted plate pushing up the overriding plateoverriding plate

– Therefore most mountain ranges are Therefore most mountain ranges are located along located along plate boundariesplate boundaries

Objective – 2: Compare and contrast active and passive Objective – 2: Compare and contrast active and passive continental margins.continental margins.

Define:Define:– Continental margin: is a boundary Continental margin: is a boundary

between continental crust and oceanic between continental crust and oceanic crustcrust

– Passive continental margin: stable areas Passive continental margin: stable areas that are that are notnot located near plate located near plate boundariesboundaries

Objective – 2: Compare and contrast active and Objective – 2: Compare and contrast active and passive continental margins.passive continental margins.

Compare and contrast Active and Compare and contrast Active and Passive Continental Margins:Passive Continental Margins:– Active – located along plate boundaries; Active – located along plate boundaries;

both lie along continental margins; both lie along continental margins; – Passive – Passive – NotNot located along any plate located along any plate

boundaries; consists of mainly marine boundaries; consists of mainly marine sediments; weathered rock;sediments; weathered rock;

Objective – 2: Compare and contrast active and Objective – 2: Compare and contrast active and passive continental margins.passive continental margins.

Looking at the Looking at the Plate Boundary MapPlate Boundary Map on on pages 712 – 713, there are a number of pages 712 – 713, there are a number of Active and Passive continental margins:Active and Passive continental margins:– Active continental margins include west coast Active continental margins include west coast

of South America; west coast of North America; of South America; west coast of North America; east coast of Japan; west coast of Indonesia;east coast of Japan; west coast of Indonesia;

– Passive continental margins include east coast Passive continental margins include east coast of N America; east coast of S America; west of N America; east coast of S America; west coast of Africa; south east coast of Africa; etc.coast of Africa; south east coast of Africa; etc.

Active continental margins: Passive margins:

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

Chapter 11 Section 2Chapter 11 Section 2

How Mountains Form:How Mountains Form:

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

Types of Stress:Types of Stress:– Forces involved in plate interactions Forces involved in plate interactions

produce features such as folds and produce features such as folds and faults.faults.

– Folded Mountains:Folded Mountains:Two plates collide, can cause folding of rockTwo plates collide, can cause folding of rockBefore two continents can collide the ocean Before two continents can collide the ocean

basin between them must close: Subductionbasin between them must close: SubductionHimalayas formed by the ocean basin Himalayas formed by the ocean basin

between India and Tibet closed due to between India and Tibet closed due to Subduction.Subduction.

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

– Dome Mountains:Dome Mountains:Nearly circular folded mountainNearly circular folded mountain Individual isolated structuresIndividual isolated structuresPlutonic dome Mountain:Plutonic dome Mountain:

– Formed by overlaying crustal rock pushed up by Formed by overlaying crustal rock pushed up by an igneous intrusion such as a an igneous intrusion such as a laccolithlaccolith..

– Center rocks (igneous) are younger than the outer Center rocks (igneous) are younger than the outer rocksrocks

Tectonic Dome Mountains:Tectonic Dome Mountains:– Result of uplifting forces that arch rock layers Result of uplifting forces that arch rock layers

upwardupward– All the rocks were present before the uplift All the rocks were present before the uplift

occurredoccurred


Fault-block MountainsFault-block Mountains– The crust is The crust is stretchedstretched (tensional forces) and (tensional forces) and

normal faults are creatednormal faults are created– Whole blocks are pushed upWhole blocks are pushed up

Horst and GrabensHorst and Grabens– Tensional stress and normal faulting cause theseTensional stress and normal faulting cause these– Between tensional faulting, grabens (large blocks) Between tensional faulting, grabens (large blocks)

have droppedhave dropped– When large blocks are thrust upward, between When large blocks are thrust upward, between

normal faults, it is called a Horstnormal faults, it is called a Horst


Define:Define: Anticline – an up-fold in rock layersAnticline – an up-fold in rock layers Syncline – down-fold in rock layersSyncline – down-fold in rock layers Stress Types:Stress Types:

– Compression – rock layers are being squeezed togetherCompression – rock layers are being squeezed together– Tension – rock layers are being stretched or pulled apartTension – rock layers are being stretched or pulled apart– Shear – rock layers are being pushed in two different, Shear – rock layers are being pushed in two different,

opposite directions.opposite directions.



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

Objective – 4: Compare and Contrast Objective – 4: Compare and Contrast Anticlines and Anticlines and SynclinesSynclines

– An anticline is an An anticline is an up-foldup-fold of the rock of the rock layerslayers

– A Syncline is a is a A Syncline is a is a down-folddown-fold of the rock of the rock layerslayers

– Both are usually caused by Both are usually caused by compressional forcescompressional forces

Objective – 4: Compare and Contrast Objective – 4: Compare and Contrast Anticlines Anticlines and Synclinesand Synclines

Syncline

Objective – 4: Compare and Contrast Objective – 4: Compare and Contrast Anticlines Anticlines and Synclinesand Synclines

Anticline

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

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



The difference between a normal fault and The difference between a normal fault and a reverse fault are the stresses that cause a reverse fault are the stresses that cause them:them:– Reverse fault Reverse fault is caused by is caused by compressional compressional

forcesforces– Normal fault Normal fault is caused by is caused by tensional forcestensional forces

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

Chapter 11 Section 3Chapter 11 Section 3

Types of MountainsTypes of Mountains

Objective – 6: Classify mountain ranges by their most Objective – 6: Classify mountain ranges by their most prominent features.prominent features.

– Folded Mountains:Folded Mountains:Two plates collide, can cause folding of rock Two plates collide, can cause folding of rock

through compressional stressthrough compressional stressBefore two continents can collide the ocean Before two continents can collide the ocean

basin between them must close: Subductionbasin between them must close: SubductionHimalayas formed by the ocean basin Himalayas formed by the ocean basin

between India and Tibet closed due to between India and Tibet closed due to Subduction.Subduction.

Objective – 6: Classify mountain ranges by their most Objective – 6: Classify mountain ranges by their most prominent features.prominent features.

– Dome Mountains:Dome Mountains:Nearly circular folded mountainNearly circular folded mountain Individual isolated structuresIndividual isolated structuresPlutonic dome Mountain:Plutonic dome Mountain:

– Formed by overlaying crustal rock pushed up by Formed by overlaying crustal rock pushed up by an igneous intrusion such as a an igneous intrusion such as a laccolithlaccolith..

– Center rocks (igneous) are younger than the outer Center rocks (igneous) are younger than the outer rocksrocks

Tectonic Dome Mountains:Tectonic Dome Mountains:– Result of uplifting forces that arch rock layers Result of uplifting forces that arch rock layers

upwardupward– All the rocks were present before the uplift All the rocks were present before the uplift

occurredoccurred

Objective – 6: Classify mountain ranges by their Objective – 6: Classify mountain ranges by their most prominent features.most prominent features.

– Fault-block MountainsFault-block Mountains– The crust is The crust is stretchedstretched (tensional forces) and (tensional forces) and

normal faults are creatednormal faults are created– Whole blocks are pushed upWhole blocks are pushed up


– Horst and GrabensHorst and Grabens– Tensional stress and normal faulting cause theseTensional stress and normal faulting cause these– Between tensional faulting, Grabens (large Between tensional faulting, Grabens (large

blocks) have droppedblocks) have dropped– When large blocks are thrust upward, between When large blocks are thrust upward, between

normal faults, it is called a Horstnormal faults, it is called a Horst


When two land masses collide, they usually When two land masses collide, they usually crumple and form crumple and form folded mountains.folded mountains.– Volcanic mountains tend to form on the Volcanic mountains tend to form on the overriding plate overriding plate

at a Subduction zone.at a Subduction zone.

Fault Block MountainsFault Block Mountains form when the earth’s form when the earth’s crust is slowly up-lifted. crust is slowly up-lifted. – The uplift has caused the crust to stretch and crack, The uplift has caused the crust to stretch and crack,

forming normal faults along the surface. As uplift forming normal faults along the surface. As uplift continues, whole blocks of crust have been pushed up.continues, whole blocks of crust have been pushed up.

Objective – 7: Compare and contrast folded mountains, Objective – 7: Compare and contrast folded mountains, dome mountains, volcanic mountains, and fault-block dome mountains, volcanic mountains, and fault-block

mountains.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

MountainsMountains

EndEnd

Chapter-11 Mountain Building Notes. Objective – 1: Explain how some of earth’s major mountain belts formed. Section 11.1 “Where Mountains Form” –Mountain.

Documents

active continental margins

continental margins

passive margins

continental crust

plate boundary slide

rock slide

mountains form mountain

contrast active