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Fold mountains
Fold mountains
Mountains created due to convergent boundaries of both
1) O-C (Rockies, Andes) 2) C-C (Himalayas, Alps)Compressive forces of platesYoungest mountains on earth
True mountains
Fold mountai
ns
Geomorph
1)Extensive mountain chain2) Great heights•3) Formed along unstable parts of the earth4) Sedimentary deposits of marine origin (C-C)
Characteristics of Fold mountains
• Pull of descending limb of convection current
• great pressure of compressive force exerted by the convection cells
Phases of mountain building
• Elongated, narrow depression on continental margins
• Here sediments from both land and ocean accumulate
Geo-syncline
• Sediments from continental crusts of both plates + geo-syncline folded
• Because of sediments of geo-syncline – marine origin
C-C collision
Fold mountains of the world
Pamir Knot
Hindu kush, Kirthar and Sulaiman Ranges
Sulai
man
ra
nge
Kirt
har r
ange
Mountains in Europe
1) Alaska range2) Southern Alps3) Dinaric Alps4) Atlas mountains5) Pyrenees6) Caucasus 7) Apennines8) Taurus 9) Elburz and Zagros
9) Hindukush10) Kirthar range11) Kunlun Shan12) Urals mountains13) Appalachian mountains14) Great Dividing Range
List of mountains to locate
• understanding of the origin and evolution of earth’s crust.
• At the time of the formation of the earth crust, first basaltic crust of ocean - breaking and melting - a lighter continental crust developed.
• collide with one another = a larger land mass.• The joints = fold-mountains.
Importance of mountain building process
Urals Mountains
mountains
Fold mountains
Block mountains
Types of mountains
Block mountains formation
• Fault-block mt.• Due to forces within
interior of the earth• Uplifted part = horst• depressed part =
Grabben• Horst => block
mountains• Grabben => rift valley
Block mountains
Phases of Divergent continental crust
African rift valley – block mountains
EuropeIndia
Example of block mountains
Fold mountains• True mountains• Compressive force - folding• Due to collision of plates (C-
C, O-C)• Folding of sedimentary
rocks
• Not true mountains• Tensile force -faulting• Diverging plates (Conti)• Differential erosion of horst
of fault – looks like mountains
Block mountains
comparison
Mountains
Plateaus
Plains
Landforms on earth
Meaning:Flat, Table land, upland, higher than surrounding areas
Plateaus
• Raised land during mountains building process• Deposition from lava• Deposition from wind• Eroded due to glaciers
Formation of Plateaus
Intermontane plateau
• Bolivia plateau• Tibetan plateau• Columbia plateau• Colorado plateau• Anatolia Plateau
(Turkey)
• Deccan plateau• Katanga plateau• Ozark plateau
(USA)• Ethiopian
highland
Continental plateau
Types of plateau
Glacial plateau• Grahwal
plateau• Laurentian
plateau (Canada)
• Columbia-snake plateau (USA)• Deccan Plateau• Shan plateau
(Myanmar)
Lava plateauTypes of Plateau
Bolivia plateauColumbia- colorado
Ozark plateauAnatolia plateau
Loess plateauLaurentian plateau
• Origin of River Congo and Zambezi
• Dense equatorial forest• Known for resources- Gold, diamonds, Copper
Katanga Plateau
• Equatorial region• Dense rainforest• Known for gold
reserve
Plateau of Mato Grasso, Brazil
• Plateau crossed by Salween river
• Irrawaddy river passed in eastern side
• Shan plateau- chief source of lead, zinc and silver Myanmar
• Known for teak forest(Burmese Teak)
Shan plateau, Myanmar
“Roof of the world” – highest and largest plateau• Source of Indus,
Brahmaputra, Salween, Mekong, Yangtse, Hwang He
• Imp role in Indian monsoon
Tibetan plateau
• Granite• Less mobile,
cannot move upward
• Backbone of fold mountains
Batholith
Mountains
Plateaus
Plains
Landforms on earth
Plains
• Meaning• Flat areas with low
heights• Best for human
habitation• Most populated areas
of the world – alluvial plains of rivers
• Depositional plains- Rivers- Sea (sub-merged coast)
• Erosional plains- Erosion of plateau
Asia Europe
Africa
South America
North America
Indus Danube
Nile Amazon
Mississippi – Missouri
Ganga –Brahmaputra
Rhine Congo Parana- Paraguay
Colorado
Yangtze (China) Rhone Niger St. Lawrence
Hwang He (China)
Po Zambezi
Yukon
Ob- Irtysh (Russia)
Don Orange
Mackenzie
Mekong (SE Asia)
Euphrates - Tigris
Important river basins of the world
Yangtze river, China
• Yangtze – 3th longest river in the world• Navigable river – 35% of China’s population• Sichuan basin – rice cultivation• Shanghai – biggest port of China• Wuhan – Iron and steel• Nanjing – textile, iron and steel • Chengdu – oil and gas• Three gorge dam• Yun ho canal – connect Yangtze with Hwang He
Important locations
Euphrates- Tigris river, Iraq
• Lake Van, • Lake Urmia• Important centers in Iraq:• Baghdad, Mosul, Kirkuk, Al Basra
Locations near Euphrates-Tigris
Amazon river, Brazil
• Largest, 2nd longest river • Selvas – equatorial rain forest • Tin, rubber in Selvas • Sertao – ranching region• Petroleum reserve at the mouth• Manaus – Iron ore, navigable • plateau of Mato Grasso – gold reserve
Locations near Amazon river
Mississippi , USA
• Temperate grasslands – Prairies• Wheat, corn and cotton cultivation• Important cites: • Kansas – agriculture• St. Pittsburg – iron and steel• New Orleans – port, ship building
Locations near Mississippi basin
Murray-Darling basin, Australia
• Temperate grassland – downs• Wheat cultivation• Sheep rearing ,Animal husbandry• Wool and dairy production
Location near Murray-darling basin
Landforms on earthMountains (fold and block)
PlateausPlains
Natural Catastrophic events
volcanism
earthquake
Tsunami
complete sequence of processes of creation and movement of magma + creation of volcanic landforms
Volcanism is not random
Reason associated with volcanism is also not random
Volcanism
Geomorpho
• 1st
• Pacific Ring of Fire• O-O convergence• O-C convergence
Distribution of Volcanism
O-O : Volcanic arcO-C :Volcanic mountains
Plate movements
2nd • O-O divergence• Basaltic – peaceful
eruption
Mid Oceanic Ridge
3th • Breaking up of
Mediterranean plates into multiple blocks
• Andesitic eruption• Frequent interaction• Mt. Etna, Mt.
Vesuvius
Mediterranean volcanism
• Mediterranean sea is residual part of Tethys sea
• Tethys sea was located between – Laurasia and Gondwana
• Collision of Africa to Laurasia – breaking up of plates of Mediterranean sea
History of Mediterranean sea
• 4th • Magma From
deep interior -Basaltic
• Fixed place - Plate movement – Island arc
• Direction of plate• Hawaii, Reunion,
Kurile, Aleutian
Hot Spot Volcanoes
Aleutian Islands
Basaltic eruption • Occur at mid-oceanic ridge
and hot spot volcanism• Basalt highly fluid – mobile• Spread across easily• Quite eruption
• Volcanic arcs, volcanic mountains
• Andesite – less fluid – less mobile
• Solidifies at short distance- intense pressure develop inside –explosive
Andesitic eruption
comparison
Basaltic eruptionAndesitic eruption
comparison
Landforms
Extrusive
Volcanic plateau
Volcanic cones
Intrusive
Dykes etc.
Volcanic Landforms
Intrusive Landforms
Intrusive Landforms• Intrusion of Magma in sedimentary rocks• Sills (Horizontal)• Dyke (Vertical)• Laccolith – magma which could not come out• Lopolith – saucer-shaped• Phacolith – shape like waves • Batholith – intrusive granitic rock
Intrusive Volcanic Landforms
Extrusive
Volcanic Plateau
Volcanic cones
Shield volcano
Cinder vol.
Composite vol.
Extrusive volcanic Landforms
• Hot spot volcano on continental crust
• Cracks on continental crust –Basaltic eruption
• Spread across the land • Layer over layer• EX. Deccan lava trapps
Lava plateaus
• Indian plate passed over a hot spot near Reunion Island
• Basaltic eruption• Layer over layers – looks
like steps => Deccan lava traps
• Soil – black soil ‘regur’
Indian Deccan trap
Spatial distribution of Lava Plateau
• Columbia-snake plateau, USA
• Ozark plateau, USA• Parana-Patagonia, S.
America• Adamawa plateau,
Africa• Bie plateau, Africa• Katanga Plateau, Africa
Deccan plateau, India• Arabian plateau• Balkan plateau, Europe• Siberian plateau, Russia• Yunan Plateau, China• Shan plateau, Myanmar• Kimberly plateau,
Australia
List of lava plateaus of the world
Extrusive
Volcanic Plateau
Volcanic cones
Shield volcano
Cinder vol.
Composite vol.
Extrusive volcanic Landforms
• Volcanic Islands (Hot spot)• Highly fluid lava
(basaltic) build dome • Gentle slope• Quite volcano• Volcanoes of Hawaii
Shield / Dome volcano
• O-C collision – volcanic mountains• Less fluid lava
(Andesitic) explode violently• Viscous lava
solidifies at short distance
• Mt. Paricutin, Mexico
Cinder cones
Volcanic mountainsEach new eruption – new layers of ash or lava
Mt. Stromboli, Mt. Vesuvius, Mt. Fuji
Composite Cones
Shield/ dome Cinder Composite
Highly fluid Less fluid / highly viscous
Fluid + viscous
Silent flow Violent eruption
Multiple and violent eruption
Gentle slope Steep slope Highest volcanoes
Small volcanoes
Small volcanoes
Large volcanoes
Types of Volcanic cones
• Geysers =fountains of Hot water
• Ground water heated by shallow source of magma
• Old faithful geyser, Yellow stone park, USA
Geysers
• Hot Spring: • Water reach deep
enough – heated by interior
• Locate any part of the world
Hot Spring
• Geyser – G/w heated by shallow magma source
• Hot spring – g/w heated by either magma source or heated rocks
• Geyser – chamber in interior – pressure – comes out like fountain
• Hot –spring - quite
Difference between geyser and Hotspring
geyser• Geysers are rare• Hot water dissolved with
silica accumulated on surface – gives different colours
• USA, - Yellowstone park
• Found anywhere• They gets different colors
from heat-loving bacteria, like cyanobacteria
• Medicinal values• Can be helpful in harness
geo-thermal energy
Hot spring
comparison
• Heated water is taken out – used for moving turbine – generation of electricity
• Cooled water flown back into interior
Geo-thermal energy
• Difficult to locate a good source of geothermal reservoir with current technology
• Difficult to dig a deep well with hard and hot bedrock
• Harmful gases can escape from the earth interior while exploration – GHG gases and dissolved toxic elements
Limitations of geo-thermal energy
volcanism
earthquake
Tsunami
Sudden movement or vibration in earth’s crust.
Release of the energy due to intense pressure + active internal dynamism of the earth
Earthquake
Geomorpho
1) Shallow focus EQ2) Intermediate focus EQ3) Deep focus EQ
Shallow focus – destructive
Types of Earthquake
At Junction of 3 plates Subduction of Pacific plate
Earthquakes in Japan
1st Collision of Plate boundariesO-O collisionO-C collisionC-C collision
Reasons behind EQ
2nd
Divergent Plate boundaries
O-O divergence MOR
Reasons behind EQ
• 3th• Transverse plate
boundaries• Friction developed
between two plates
Reasons behind EQ
4th Mediterranean sea regionNumerous small platesFrequent interactions
Reasons behind EQ
5th Craton = stable part of crustRe-emergence of old fractures
6th Human Induced 1) RIS2) mining3) Nuclear testing
Reasons behind EQ
volcanism
earthquake
Tsunami
Submarine EQSudden disturbances of underlying plates transmit the shock waves to surface waves
Tsunami
Geomorpho
Normal wavesSpeed – 100 kmphCover shorter distancesWavelength ~100 km
• Speed – 700 kmph• Cover longer distances• Wavelength – > 150 km
Tsunami waves
comparison
• Distance between two crests of troughs = wavelength
• Waves of Tsunami are wider than normal waves of the ocean water
wavelength
• EQ on ocean crust – uplift the water upward
• Tsunami wave generated
• Vessels in the mid-sea cannot recongnise the tsunami waves
• Sea water recede at the shore
Phase 1
• At coast – depth decrease – wavelength decreases – wave height increases
• A huge wall of water – 10-12 floor high created
• Enormous energy released at the shore
Phase 2
• Hit the coast• Tsunami- not a single
wave but multiple waves
• 4th and 8th waves are the most dangerous
• Time lapse between each waves – 15 to 50 minutes
Phase 3
Phases of tsunami
• Tsunami Early warning system- gives warning in 10 minutes of submarine earthquake
• Indian National centre for Ocean Information Sciences (INCOIS),Hyderabad
• To capture Tsunami wave amplitude on 24x7 basis• real time sea-level sensors with bottom pressure
recorders• HF radars for coastal currents• Coastal tide gauge stations
Indian preparedness against Tsunami
Catastrophic events on earth
Their reasons and distributions
VolcanismEQTsunami