LANDFORMS OF THE EARTH Prepared by: Savita Kukreti Pawar Public School Kandivali.
Post on 16-Dec-2015
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How are they formed?Series of concentric rock layersBad conductorsInternal heat – rock meltsThis leads to several conditions
which cause landform development on the surface of the earth.
Causes of landforms development on the surface of the earth
1) Plate tectonics
2) Uplift and submergence
3) Sudden forces
4) Exogenic forces
Plate tectonics
Plates float on semi molten Asthenosphere.Push, collide or slide.Sedimentary rock deposits- disturbance/
compressed. Results foldingfold mountain – orogenic movements.
Uplift and submergenceForces from earth’s center to the surfaceVertical movementsLarge scale uplift or subsidenceContinent building – epeirogenic
movementsBlock mountainsRift valleys
Sudden forcesEarthquakes and volcanoesConstructive forcesThey create relief featuresVolcanoes – mountains, plateaus and
plainsEarthquakes – faults and lakes
Exogenic Forces
Forces operating on the surfaceExternal forcesDestructive forces – weathering and
erosionBoth erosion and deposition
FORCES CAUSING LANDFORMS
ENDOGENIC
DIASTROPHIC
EPIOROGENI
CUPLIFT &
SUBMERG
ENCE
(CONTINEN
T BUILDING
FORCES
)
OROGENI
C
(MOUNTAIN MAKIN
G FORCES
)
SUDDEN CONSTRUC
TIVE FORCES
VOLCANIC ERUPTIONS
EARTHQUAKES
EXOGENIC
ALLUVIAL AND EROSIONAL PLAINS
FEATURES OF FOLD MOUNTAINS
Feature 2: most of these mountains are constituted of sedimentary rocks formed due to deposition and
consolidation of sediments in shallow oceans
FEATURES OF FOLD MOUNTAINS
Feature iv: most fold mountains are found on the margins of continents
Feature v : fold mountains are associated with volcanic activity and has many active volcanoes
Plateaus Plateau is defines as an area of high ground, 500 feet above the ground level
The uplands have steep slope on one side
The upper part is generally flat and is called tableland.
Intermontane Plateau Highest and most
extensive Surrounded by hills
and mountains on all sides
Formed along with fold mountains.
Example : the Tibetan plateau and Columbian plateau
Piedmont PlateausMountain ranges on
one side and plains on one side.
The side facing the plains has steep slopes.
Residual plateaus – derived from ancient fold system.
Example : Patagonian plateau
Volcanic Plateau•Derived from lava flows from volcanic eruptions.•Example : The Plateau of Peninsular India.•Columbian plateau.
Uplifted Plateau
During volcanic activity the endogenic forces may uplift the middle portion of the landmass.
The sides get rounded forming a dome shaped tableland.
Example : Chota Nagpur plateau.
Plains
What are Plains
An extensive area of low land with a level or gently undulating surface.Most intriguing landform processThere are endless variations – hence it is an imprint of past and present landform.
Structural PlainsFormed due to uplift
or subsidence of land.
Diastrophic forces may cause uplift of a portion of land beneath the ocean water or may cause submergence of coastal land under ocean water.
Example of structural plains
The Great Plains are formed due to uplift of land submerged under water
The Coromandel plains in India are the result of mild subsidence followed by sedimentation.
Peneplains
Landscapes in which almost all hills have been worn down as a result of erosion.
Peneplains literally means almost a plain.
GLACIAL EROSION
These plains have rounded peaks and worn down ice scoured shield lands
Due to the action of the glacier the area gets worn down and the height is reduced.
Wind eroded plainsStrong winds pick up weathered materials and deposit them else whereThese formations are called pediplains.They are also called reg, serir and hamada in sahara desert.
Karst plainsDue to chemical weathering the
area gets eroded and produces undulating topography.
This type of features are mostly found in limestone landscapes where chemical weathering takes place.
DEPOSITIONAL PLAINS These plains are caused due the
deposition of various agents such as River Wind Sea
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