EROSION AND DEPOSITION LANDFORMS BY-AKANKSHA SONI
EROSION AND DEPOSITION EROSION involves acquisition and transportation of rock debris. When massive rocks break into smaller fragments, geomorphic agents like running water, glaciers, wind, waves transport it to other places. By erosion, relief degrades. It is largely responsible for change on earth's surface Deposition-It is the result of erosion. When fragments loose their energy, they settle down. The coarser materials settle first and fine ones later. Same geomorphic agents are responsible for it
Geomorphic agents and their landforms RUNNING WATER 1 )Youth: It represents rivers in highlands like mountains, hills etc. The flow is strong and vertical erosion is experienced. 2) Mature: It is dominated by lateral erosion with transportation 3) Old: It is dominated by deposition MIDDLE LS -DELTA VEKTICAL VALLEY
Erosional landform Valley-Types such as V-shaped, gorge, canyon can be seen. It begins with rills which gradually develop into gullies and rise into valley. Plunge pools/potholes- Found at the foot of waterfalls which gets deepend. Water whi falls on soft rocks produced erosion with pressure. Meanders- Represent serpentine flow of river. Outer banks are formed due to bank erosion with circular movement in sediments, whichd . . epos it in inner bank. Depositional landform Alluvial fans- When streams reach to lower level, there is decline in energy and deposition occurs according to size of sediments Meanders . Erosion Erosion Ox bow lake-The part of river which is detached from meander becomes an ox-bow lake Deposition Erosion
GLACIERS Masses of ice sheets over the land are glaciers. The movement could be very slow and flow with gravity. Erosion is heavy due to ice weight. EROSIONAL FORMS- Cirque- Found at head of glacial valley. They are deep long and wide basins lacial valley-Trough like and U-shaped with broad floor and steer sides DEPOSITIONAL LANDFORMS- Moraines- Long ridges of deposits of glacial till, present at end of glaciers. Outwash plains-The plains at foot of glacial mountains Drumlins- Smooth oval shaped ridge like feature made of glacial till, gravel and sand.
WAVESAND CURRENTS EROSIONAL FORMS- Cliff cut-Wave cut cliff and terraces and erosion is prominent here. Caves-Lashing against base create hollows and when these hollows get widened, called as caves. Beaches and dunes- Beaches are temporary feature dominated by deposition. They may disappear Bars, barriers, spits- Sand gets settled off shore, parallel to coast called as Off shore bar. Further When they get keyed up at bay, called as Spits DEPOSITIONAL FORMS in some season. Most sediment goes from land and flow settle from wave erosion addition of sand becomes Barrier bar Sand Deposits Longshore current Sand spit Baymouth bar Barrier island Bay Inlet Sea island Lagoon Bay Tombolo Beach
WINDS EROSIONAL FORMS Playas- In a basin with mountains around, drainage is towards the centre of basin and due to gradual deposition of sediment and sufficient water, it forms shallow lake called as playa. With evaporation, they become a place for salt deposition Mushroom rocks- Many rock in deserts get easily worn down by wind deflation and abrasion leaving beautiful polished rocks in shape of mushroom Barchan Seif DEPOSITIONAL FORMS Sand dunes- Barchan, Seif, Parabolic, Transverse, Longitudinal Paraboli ongitudinal