Presentation on theme: "LANDFORMS OF THE EARTH Prepared by: Savita Kukreti Pawar Public School Kandivali."— Presentation transcript:
LANDFORMS OF THE EARTH Prepared by: Savita Kukreti Pawar Public School Kandivali
What are landforms? A landform is a natural feature of the earth’s surface.
How are they formed? Series of concentric rock layers Bad conductors Internal heat – rock melts This 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 folding fold mountain – orogenic movements.
Uplift and submergence Forces from earth’s center to the surface Vertical movements Large scale uplift or subsidence Continent building – epeirogenic movements Block mountains Rift valleys
Sudden forces Earthquakes and volcanoes Constructive forces They create relief features Volcanoes – mountains, plateaus and plains Earthquakes – faults and lakes
Exogenic Forces Forces operating on the surface External forces Destructive forces – weathering and erosion Both erosion and deposition
FORCES CAUSING LANDFORMS ENDOGENICDIASTROPHIC EPIOROGENIC UPLIFT & SUBMERGENCE (CONTINENT BUILDING FORCES) OROGENIC (MOUNTAIN MAKING FORCES) SUDDEN CONSTRUCTIVE FORCES VOLCANIC ERUPTIONS EARTHQUAKESEXOGENIC ALLUVIAL AND EROSIONAL PLAINS
LANDFORMS AND THEIR TYPESMOUNTAINS PLATEAUS PLAINS
TYPES OF MOUNTAINS FOLDMOUNTAINS BLOCKMOUNTAINS VOLCANIC MOUNTAINS
FOLD MOUNTAINS How are fold mountains formed?
FEATURES OF FOLD MOUNTAINS 1. Irregular folds in fold mountains due to unequal pressure
What does this image show
Which type of rocks have this feature? How are these rocks formed?
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 3. FOLD MOUNTAINS HAVE GREATER LENGTH BUT COMPARATIVELY SMALL WIDTH
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
BLOCK MOUNTAINS How are block mountains formed
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
LOCATION OF TIBET PLATEAU
Piedmont Plateaus Mountain 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.
LOCATION OF COLOMBIAN 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.
CHOTA NAGPUR PLATEAU
Plains What are Plains An extensive area of low land with a level or gently undulating surface. Most intriguing landform process There are endless variations – hence it is an imprint of past and present landform.
Types Of Plains StructuralErosionalDepositional
Structural Plains Formed 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.
Location of the great plains of USA
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.
ERROSIONAL PLAINS These plains are formed by agents of erosion like River Wind Chemical weathering
Peneplains Landscapes in which almost all hills have been worn down as a result of erosion. Peneplains literally means almost a plain.
Peneplains – some resistant peaks remaining
LORRAINE PLAIN IN FRANCE
LOCATION OF LORRAINE 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.
PLAINS OF GLACIAL EROSION
Wind eroded plains Strong winds pick up weathered materials and deposit them else where These formations are called pediplains. They are also called reg, serir and hamada in sahara desert.
Karst plains Due 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