Landforms

Landforms

A.2.1] Mountains

Definition

Mountains are elevated landforms that rise prominently above the surrounding area, typically with steep slopes and a peak.

Types of Mountains
TypeDescriptionFormation
Fold MountainsFormed by the folding of rock layers due to tectonic compressionHimalayas, Alps
Block MountainsFormed by the uplift and faulting of the Earth’s crustSierra Nevada, Vosges
Volcanic MountainsFormed by the accumulation of volcanic materialMount Fuji, Mount Kilimanjaro
Dune MountainsFormed by wind deposition in arid regionsNot a standard type; often confused with dunes
Formation Processes
  • Tectonic Activity: Folding, faulting, and compression
  • Volcanic Activity: Eruption and accumulation of lava and ash
  • Erosion and Uplift: Differential erosion of softer rocks
Key Facts (SSC, RRB)
  • Fold mountains are the most common type.
  • The Himalayas are the highest and youngest fold mountains.
  • Volcanic mountains are often found near tectonic plate boundaries.

A.2.2] Plateaus

Definition

Plateaus are flat-topped elevated landforms with steep slopes on at least one side.

Types of Plateaus
TypeDescriptionFormation
Volcanic PlateausFormed by the solidification of lava flowsDeccan Plateau, Columbia Plateau
Erosional PlateausFormed by erosion of surrounding areasTibetan Plateau
Residual PlateausForm, due to differential erosionChota Nagpur Plateau
Tectonic PlateausFormed by uplift of the Earth’s crustTibetan Plateau
Formation Processes
  • Volcanic Activity: Lava flows solidify to form flat surfaces
  • Erosion: Removal of surrounding material leaves elevated flat areas
  • Tectonic Uplift: Crustal movement raises the land
Key Facts (SSC, RRB)
  • The Deccan Plateau is a volcanic plateau formed during the Cretaceous period.
  • The Tibetan Plateau is the highest and largest plateau in the world.
  • Residual plateaus are often found in arid regions.

A.2.3] Plains

Definition

Plains are large, flat or gently undulating areas of land, typically lower in elevation.

Types of Plains
TypeDescriptionFormation
Alluvial PlainsFormed by river depositionIndo-Gangetic Plain, North China Plain
Coastal PlainsFormed by sea depositionEastern Coastal Plain of India
Interior PlainsFormed by erosion and depositionGreat Plains of North America
Flood PlainsFormed by periodic floodingGanges-Brahmaputra flood plains
Formation Processes
  • River Deposition: Sediments carried by rivers settle to form alluvial plains
  • Marine Deposition: Sediments from the sea form coastal plains
  • Erosion and Weathering: Gradual leveling of landforms
Key Facts (SS. C, RRB)
  • The Indo-Gangetic Plain is the largest alluvial plain in the world.
  • Alluvial plains are highly fertile and important for agriculture.
  • Coastal plains are often associated with deltas and estuaries.

A.2.4] Glaciated Landforms

Definition

Glaciated landforms are features created by the movement and deposition of glaciers.

Types of Glaciated Landforms
TypeDescriptionFormation
U-shaped ValleysFormed by glacial erosionYosemite Valley, Patagonia
CirquesBowl-shaped depressions at the head of a valleyAlps, Himalayas
HornsSharp, pyramid-shaped peaks formed by glacial erosionMatterhorn, Pyramid Peak
GlaciersLarge masses of ice that move slowly over landGreenland, Antarctica
MorainesAccumulations of rock debris deposited by glaciersTerminal, lateral, medial moraines
Formation Processes
  • Glacial Erosion: Abrasion and plucking of rock
  • Glacial Deposition: Sediment left behind as glaciers retreat
Key Facts (SSC, RRB)
  • U-shaped valleys are a hallmark of glacial activity.
  • The Alps and the Himalayas have significant glacial landforms.
  • Moraines are important indicators of past glacial activity.

A.2.5] Volcanic Landforms

Definition

Volcanic landforms are features created by volcanic activity, including eruptions, lava flows, and ash deposits.

Types of Volcanic Landforms
TypeDescriptionFormation
Volcanic ConeCone-shaped hill formed by accumulated volcanic materialCinder cones, composite cones
CalderaLarge depression formed by the collapse of a volcanoCrater Lake, Yellowstone
Lava PlateausBroad, flat areas formed by extensive lava flowsDeccan Plateau, Columbia Plateau
Volcanic DomesRounded hills formed by viscous lavaMount St. Helens
Fissure PlainsFlat areas formed by fissure eruptionsIceland
Formation Processes
  • Lava Eruptions: Magma extrusion and solidification
  • Ash and Tephra Deposition: Accumulation of volcanic debris
  • Volcanic Collapse: Formation of calderas
Key Facts (SSC, RRB)
  • The Deccan Plateau is a volcanic plateau formed during the Cretaceous period.
  • Composite volcanoes are also known as stratovolcanoes.
  • Calderas are often associated with explosive eruptions.

A.2.6] Desert Landforms

Definition

Desert landforms are features created by wind erosion and deposition in arid regions.

Types of Desert Landforms
TypeDescriptionFormation
DunesMounds of sand formed by windBarchan, transverse, linear dunes
YardangsRidge-like features formed by wind erosionCentral Asia
Deflation BasinsDepressions formed by removal of loose sedimentsSahara Desert
InselbergsIsolated hills or mountains in a desertNamib Desert
Alluvial FansFan-shaped deposits at the base of mountainsDesert margins
Formation Processes
  • Wind Erosion: Abrasion and deflation of loose sediments
  • Wind Deposition: Accumulation of sand and dust
Key Facts (SSC, RRB)
  • Barchan dunes are the most common type of dune in deserts.
  • Yardangs are often found in arid regions with strong winds.
  • Inselbergs are remnants of ancient mountains.

A.2.7] Riverine Landforms

Definition

Riverine landforms are features created by the action of rivers, including erosion, transportation, and deposition.

Types of Riverine Landforms
TypeDescriptionFormation
V-shaped ValleysFormed by river erosionYoung rivers
Flood PlainsFlat areas formed by periodic floodingGanges-Brahmaputra
MeandersCurved bends in a riverMature rivers
Oxbow LakesLake formed by the cutoff of a meanderMature rivers
DeltasFan-shaped deposits at the mouth of a riverGanges Delta
Alluvial FansFan-shaped deposits at the base of mountainsDesert margins
Formation Processes
  • Erosion: Cutting through rock and soil
  • Transportation: Movement of sediments by water
  • Deposition: Accumulation of sediments in low-energy areas
Key Facts (SSC, RRB)
  • Meanders are common in mature rivers.
  • Deltas are highly fertile and support agriculture.
  • Flood plains are important for agriculture and human settlement.