Structure of India: Geological Formation, Relief and Drainage, ISC Class 12

What Structure of India – Geological Formation, Relief and Drainage is about

Weightage: CISCE publishes no chapter or unit weightage for ISC Geography. Structure of India – Geological Formation, Relief and Drainage is part of 1. Physical Environment (ii) of the 2027 syllabus and can be asked anywhere in the 70-mark Paper I (Section A one-mark and map items, Section B 4-mark short answers, Section C 7-mark long answers).Source: CISCE ISC Geography (853) syllabus, examination year 2027; ISC 2027 specimen question paper

Key concepts

Geological eras and the evolution of the three structural units

Standard geological eras (oldest to youngest): Precambrian (Archaean and Proterozoic), Palaeozoic, Mesozoic, Cenozoic (Tertiary and Quaternary).
Indian geological divisions: Archaean (oldest crystalline rocks: gneiss and schist; the Dharwar system with iron ore); Purana (Cuddapah and Vindhyan systems); Dravidian (Palaeozoic); Aryan (from the Upper Carboniferous: Gondwana system with coal, Deccan Trap lavas of the Cretaceous, Tertiary formations of the Himalayas, Quaternary alluvium of the plains).

Evolution of the Peninsular Plateau
1. It is part of the ancient southern continent Gondwanaland, made of very old Precambrian crystalline rocks: a stable, rigid block.
2. Gondwanaland broke up and the Indian plate drifted northwards.
3. Fissure eruptions at the end of the Cretaceous spread basalt lava over the north-west Deccan (the Deccan Trap).
4. Faulting created rift valleys (Narmada, Tapi) and block features; long erosion has worn it into a low, rounded plateau with residual hills such as the Aravallis.

Evolution of the Himalayas
1. A long, narrow sea, the Tethys, lay between Angaraland (north) and Gondwanaland (south) and received thick sediments from both.
2. The Indian plate moved northwards and pushed beneath (collided with) the Eurasian plate.
3. The sediments in the Tethys were compressed and folded into a series of fold mountains, uplifted in several phases during the Tertiary.
4. The movement continues, so the Himalayas are still rising and the region has frequent earthquakes.

Evolution of the Great Plains
1. As the Himalayas rose, a long depression (foredeep or trough) formed between them and the Peninsula.
2. Rivers from the Himalayas and the Peninsula filled it with alluvium during the Quaternary, thousands of metres thick, creating flat, fertile plains.

Worked example

[2] Briefly explain the geological evolution of the Himalayas. (Understand)

Try it first, then show the solutionSolution

1. The Indian plate moved north and pushed beneath the Eurasian plate - 1 mark.
2. Sediments of the Tethys Sea were compressed and folded into fold mountains, uplifted in stages in the Tertiary - 1 mark.

Answer: The Indian plate drifted northwards and collided with, and pushed beneath, the Eurasian plate. The thick sediments deposited in the Tethys Sea between them were squeezed, folded and uplifted in several phases during the Tertiary period to form the Himalayas, which are still rising.

Difference between the Peninsular Plateau and the Himalayas

1. Age: Peninsular Plateau - one of the oldest landmasses (Precambrian); Himalayas - young fold mountains (Tertiary).
2. Origin: Plateau - part of Gondwanaland, a stable block; Himalayas - formed by folding of Tethys sediments in a plate collision.
3. Rocks: Plateau - igneous and metamorphic crystalline rocks (granite, gneiss, basalt); Himalayas - sedimentary rocks, folded and faulted.
4. Relief: Plateau - low, worn-down, flat-topped, with rounded residual hills (average 600-900 m); Himalayas - lofty, rugged peaks over 8,000 m with deep valleys.
5. Stability: Plateau - stable, few earthquakes; Himalayas - unstable, earthquakes and landslides common.
6. Rivers: Plateau - old, seasonal rivers with broad, shallow valleys; Himalayas - young, perennial rivers with gorges and V-shaped valleys.
7. Resources: Plateau - rich in minerals; Himalayas - forests, hydel potential, glaciers.

Worked example

[4] Give four differences between the Peninsular Plateau and the Himalayas. (Analyse)

Try it first, then show the solutionSolution

1. Age: oldest Precambrian landmass versus young Tertiary fold mountains - 1 mark.
2. Rocks: igneous and metamorphic versus folded sedimentary - 1 mark.
3. Relief: low, rounded, 600-900 m versus lofty, rugged, over 8,000 m - 1 mark.
4. Stability: stable block versus unstable, earthquake-prone - 1 mark.

Answer: The Peninsular Plateau is one of the oldest landmasses, made of Precambrian igneous and metamorphic rocks, while the Himalayas are young fold mountains of folded sedimentary rocks. The plateau is low and worn down, mostly 600-900 m with rounded hills, whereas the Himalayas rise above 8,000 m with rugged peaks and deep valleys. The plateau is a stable block, while the Himalayas are unstable and prone to earthquakes.

The Himalayan mountain complex

Structure: the Himalayas are a series of parallel ranges (an orthoclinal structure) running from the Indus to the Brahmaputra for about 2,400 km, convex to the south.

Three parallel ranges
1. Greater Himalayas (Himadri): the northernmost and highest, average height about 6,000 m, with the highest peaks (Everest in Nepal; Kanchenjunga, India's highest at about 8,586 m); snow-covered, source of glaciers; core of granite.
2. Lesser Himalayas (Himachal): average 3,700-4,500 m; ranges such as Pir Panjal and Dhauladhar; hill stations (Shimla, Mussoorie, Darjeeling); valleys like Kashmir and Kullu.
3. Outer Himalayas (Shiwaliks): the southernmost and lowest, 900-1,100 m; made of unconsolidated river deposits; longitudinal valleys called duns (Dehradun).
Trans-Himalayas north of the Greater Himalayas: the Karakoram (with K2, about 8,611 m), Ladakh and Zaskar ranges.

Offshoots

• North-west: ranges such as the Hindu Kush and Sulaiman run beyond India.
• North-east (Purvanchal): after the Dihang gorge the Himalayas turn south as the Patkai Bum, Naga hills, Manipur hills and Mizo (Lushai) hills along the Myanmar border. (The Garo, Khasi and Jaintia hills of Meghalaya are a detached part of the Peninsular block.)

Western versus Eastern Himalayas
1. Western Himalayas rise gradually from the plains and are wider; Eastern Himalayas rise abruptly from the plains and are narrower.
2. Western Himalayas are drier with less rainfall; Eastern Himalayas receive very heavy rainfall.
3. Western Himalayas have coniferous forests and alpine pastures; Eastern Himalayas have dense evergreen and broad-leaved forests.

Regional divisions (from west to east, by rivers)
1. Kashmir or Punjab Himalayas: between the Indus and the Sutlej.
2. Himachal/Uttaranchal or Kumaon Himalayas: between the Sutlej and the Kali.
3. Nepal Himalayas: between the Kali and the Tista.
4. Assam Himalayas: between the Tista and the Dihang (Brahmaputra).

Worked example

[4] Describe the three parallel ranges of the Himalayas. (Understand)

Try it first, then show the solutionSolution

1. Greater Himalayas: highest, about 6,000 m average, snow-capped peaks such as Kanchenjunga - 1 mark.
2. Lesser Himalayas: 3,700-4,500 m; Pir Panjal, Dhauladhar; hill stations and valleys - 1 mark.
3. Shiwaliks: lowest, 900-1,100 m, made of river deposits; duns - 1 mark.
4. Parallel, arc-shaped ranges running about 2,400 km from Indus to Brahmaputra - 1 mark.

Answer: The Himalayas consist of three parallel arc-shaped ranges running about 2,400 km from the Indus to the Brahmaputra. The Greater Himalayas (Himadri), averaging about 6,000 m, are snow-covered and contain the highest peaks. The Lesser Himalayas (Himachal), 3,700-4,500 m, include the Pir Panjal and Dhauladhar ranges and many hill stations. The Outer Himalayas or Shiwaliks, 900-1,100 m, are made of river deposits and contain longitudinal valleys called duns.

The Indus-Ganga-Brahmaputra Plains

Extent: a vast plain about 2,400 km long and 150-300 km wide, between the Himalayas and the Peninsula, built of alluvium; very gentle slope and little relief.

Relief features (from the foothills southwards)
1. Bhabar: a narrow belt, about 8-16 km wide, along the foot of the Shiwaliks, where rivers deposit pebbles and boulders; it is so porous that small streams disappear underground; not suitable for farming.
2. Tarai: south of the bhabar, about 15-30 km wide, where the underground streams re-emerge; marshy, with dense forest and wildlife (much now cleared for farming).
3. Bhangar: older alluvium on higher ground above the flood level, with lime nodules (kankar); less fertile.
4. Khadar: newer alluvium on the floodplains, renewed by floods every year; very fertile.
5. Doab: the land between two rivers (for example the Ganga-Yamuna doab).

Regional divisions
1. Rajasthan plain, including the Great Indian (Thar) Desert: dry, with sand dunes and salt lakes.
2. Punjab plain: built by the Indus and its tributaries; made of doabs.
3. Ganga plain: the largest part, from the Yamuna to Bengal, with the delta in the east.
4. Brahmaputra (Assam) plain: a narrow valley with river islands such as Majuli.

Worked example

[2] Rivers from the Himalayas drop pebbles in a narrow belt 8 to 16 km wide along the foot of the Shiwaliks. Name this feature and give one other characteristic. (Recall)

Try it first, then show the solutionSolution

1. The feature is bhabar - 1 mark.
2. It is so porous that streams disappear underground; unsuited to farming - 1 mark.

Answer: Bhabar. It is made of porous pebbles and boulders, so small streams disappear underground in it, and it is unsuitable for agriculture.

The Peninsular Plateau and the Ghats

Extent: a triangular tableland south of the plains, bounded by the Aravallis in the north-west, the Rajmahal hills in the east, the Western Ghats in the west and the Eastern Ghats in the east; average height 600-900 m; slopes generally from west to east.

Divisions
1. Malwa Plateau: between the Aravallis and the Vindhyas; covered by lava and black soil; drained by the Chambal, whose ravines form badlands.
2. Chotanagpur Plateau: in Jharkhand and nearby, rich in minerals (coal, iron ore, mica); drained by the Damodar, which flows through a rift valley.
3. Deccan Plateau: south of the Satpuras, between the Western and Eastern Ghats; north-western part covered by Deccan Trap basalt.

Badlands: land cut into deep gullies and ravines by running water, as in the Chambal valley.
Aravallis: among the oldest fold mountains in the world, now worn-down residual hills; highest point Guru Shikhar (Mount Abu).

Western Ghats versus Eastern Ghats
1. Height: Western Ghats are higher, average about 900-1,600 m (Anai Mudi, about 2,695 m, the highest peak of South India); Eastern Ghats are lower, average about 600 m.
2. Continuity: Western Ghats are continuous, broken only by passes (Thal, Bhor, Pal); Eastern Ghats are discontinuous, cut by rivers.
3. Width: Western Ghats are narrow; Eastern Ghats are broader.
4. Rivers: the main Peninsular rivers (Godavari, Krishna, Kaveri) rise in the Western Ghats; no large river rises in the Eastern Ghats.
5. Slope: the Western Ghats drop steeply to the west coast; the Eastern Ghats slope gently.

Worked example

[3] Give three differences between the Western Ghats and the Eastern Ghats. (Analyse)

Try it first, then show the solutionSolution

1. Western Ghats are higher (about 900-1,600 m); Eastern Ghats lower (about 600 m) - 1 mark.
2. Western Ghats are continuous, crossed by passes; Eastern Ghats are broken by rivers - 1 mark.
3. Major rivers rise in the Western Ghats; none in the Eastern Ghats - 1 mark.

Answer: (1) The Western Ghats are higher, averaging about 900-1,600 m, while the Eastern Ghats average only about 600 m. (2) The Western Ghats form a continuous wall crossed only by passes, while the Eastern Ghats are broken into separate hills by rivers. (3) The great Peninsular rivers such as the Godavari, Krishna and Kaveri rise in the Western Ghats, whereas no major river rises in the Eastern Ghats.

Coastal plains, islands and drainage

Western versus Eastern Coastal Plains
1. Location: between the Western Ghats and the Arabian Sea; between the Eastern Ghats and the Bay of Bengal.
2. Width: western is narrow; eastern is wider.
3. Divisions: western - Kachchh and Kathiawar, Konkan, Kanara (Karnataka), Malabar; eastern - Utkal (Odisha), Northern Circars (Andhra Pradesh), Coromandel (Tamil Nadu).
4. Landforms: western rivers form estuaries, and lagoons (kayals) line the Malabar coast; eastern rivers form large deltas (Mahanadi, Godavari, Krishna, Kaveri), with lagoons such as Chilika and Pulicat.
5. Ports: the indented western coast has natural harbours; the eastern coast is smoother.

Islands

• Andaman and Nicobar Islands (Bay of Bengal): several hundred islands, larger, hilly, the submerged extension of the Arakan Yoma mountains of Myanmar; Barren Island has an active volcano; dense forests.
• Lakshadweep (Arabian Sea): 36 small, low islands of coral origin (atolls and reefs), near the Kerala coast.

Sources of the main rivers

• Ganga: Gangotri glacier (as the Bhagirathi, at Gaumukh), joined by the Alaknanda at Devprayag.
• Yamuna: Yamunotri glacier.
• Indus: near Lake Mansarovar in Tibet.
• Sutlej: Rakas Tal near Mansarovar in Tibet.
• Brahmaputra: Chemayungdung glacier near Mansarovar (as the Tsangpo).
• Mahanadi: near Sihawa in Chhattisgarh.
• Godavari: Trimbakeshwar, Nashik district (Maharashtra).
• Krishna: near Mahabaleshwar (Maharashtra).
• Kaveri: Talakaveri, Brahmagiri hills, Kodagu (Karnataka).
• Narmada: Amarkantak plateau (Madhya Pradesh).
• Tapi: Multai, Betul district (Madhya Pradesh).

Himalayan versus Peninsular rivers
1. Source: glaciers and rain versus rain only.
2. Flow: perennial versus seasonal.
3. Length and basin: long, large basins versus shorter, smaller basins.
4. Valleys: deep gorges and V-shaped valleys (young, antecedent) versus broad, shallow valleys (old, mature).
5. Courses: meandering in the plains, shifting beds versus fixed, straight courses.
6. Mouths: large deltas versus deltas (east-flowing) and estuaries (Narmada, Tapi).
7. Uses: irrigation and navigation in plains versus hydel power (falls and rapids).

Worked example

[2] How is the Himalayan river system different from the Peninsular river system? Give two points. (Analyse)

Try it first, then show the solutionSolution

1. Himalayan rivers are perennial, fed by glaciers and rain; Peninsular rivers are seasonal and rain-fed - 1 mark.
2. Himalayan rivers are long, with deep gorges and large deltas; Peninsular rivers are shorter, with shallow valleys and smaller deltas or estuaries - 1 mark.

Answer: (1) Himalayan rivers are perennial, fed by melting glaciers as well as rain, while Peninsular rivers depend on the monsoon and are seasonal. (2) Himalayan rivers are long, cut deep gorges and build large deltas, whereas Peninsular rivers are shorter, flow in broad shallow valleys and form smaller deltas or, in the case of the Narmada and Tapi, estuaries.

Structure of India – Geological Formation, Relief and Drainage in real life

Each concept, met in an everyday situation. Read the situation, answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Topics in this chapter

• Coastal Plains, Islands and River Systems of India
• Geological Evolution of India and the Himalayan Mountain Complex
• Northern Plains, Peninsular Plateau and the Western and Eastern Ghats

Structure of India – Geological Formation, Relief and Drainage: key facts

Indian geological divisions

Archaean - Purana (Cuddapah, Vindhyan) - Dravidian - Aryan (Gondwana, Deccan Trap, Tertiary, Quaternary)

Dharwar: iron ore; Gondwana: coal.

Himalayan ranges

$Greater(about6,000m),Lesser(3,700-4,500m),Shiwaliks(900-1,100m)$

Kanchenjunga about 8,586 m; K2 about 8,611 m (Karakoram).

Regional Himalayas

$Kashmir/Punjab(Indus-Sutlej),Kumaon(Sutlej-Kali),Nepal(Kali-Tista),Assam(Tista-Dihang)$

By rivers.

Plains features

$Bhabar(8-16km,pebbles)-Tarai(marshy)-Bhangar(old)-Khadar(new)$

Doab = land between two rivers.

Ghats

$Western:continuous,higher,narrow;Eastern:broken,lower,broad$

Anai Mudi about 2,695 m.

River sources

$Godavari-Trimbakeshwar;Krishna-Mahabaleshwar;Kaveri-Talakaveri;Narmada-Amarkantak;Tapi-Multai;Mahanadi-Sihawa$

Ganga - Gangotri; Yamuna - Yamunotri; Indus, Sutlej, Brahmaputra - near Mansarovar.

How the board asks Structure of India – Geological Formation, Relief and Drainage

The question patterns to expect, and the method that works for each.

Tricks to remember Structure of India – Geological Formation, Relief and Drainage

Short memory aids. Say each one aloud once, then use it on a question the same day.

• Plains from the hills: 'Bha-Ta-Bha-Kha'

  Bhabar, Tarai, Bhangar, Khadar from the foothills to the river.

  Use it when: Order of plains features.

• Himalayan regions: 'P-K-N-A' between 'I-S-K-T-D'

  Punjab, Kumaon, Nepal, Assam between Indus, Sutlej, Kali, Tista, Dihang.

  Use it when: Regional divisions.

• Peninsular river sources: 'Tri-Maha-Tala-Amar-Mul-Si'

  Trimbak (Godavari), Mahabaleshwar (Krishna), Talakaveri (Kaveri), Amarkantak (Narmada), Multai (Tapi), Sihawa (Mahanadi).

  Use it when: River sources.

Structure of India – Geological Formation, Relief and Drainage: board-level solved questions

Ordered from board level to HOTS. Cover the solution, write your own, then compare step by step.

Case-study practice (Section D style)

Read the situation, then answer every part. In the board paper this is a 7-mark question split into 2 + 2 + 2 + 1 marks.

Where the marks are

How a typical answer is split into step marks. Show every step: a right final answer alone rarely earns full marks.

Where students lose marks in Structure of India – Geological Formation, Relief and Drainage

The slips examiners see most often, and what to write instead.

• ✗Mistake: Bhangar for bhabar

  CISCE examiners' comments, 2025: candidates 'Identified the feature as Bhangar instead of Bhabar'.

  ✓Do this: Pebbles at the foothills = bhabar; old raised alluvium = bhangar.

  Usually costs: 1 mark.

• ✗Mistake: Comparing landforms when river systems are asked

  CISCE examiners' comments, 2024: candidates 'Compared physical divisions (Himalayas vs Peninsular Plateau) instead of the two drainage systems'.

  ✓Do this: Himalayan versus Peninsular rivers: source, flow, length, valleys, mouths.

  Usually costs: 2 marks.

• ✗Mistake: Wrong Ghats facts and units

  CISCE examiners' comments, 2024: candidates 'Wrote about eastern and western coastal plains or Himalayas instead of the Ghats' and 'Gave wrong altitude and width units and incorrect comparisons'.

  ✓Do this: Learn heights in metres and widths in km; keep Ghats separate from coastal plains.

  Usually costs: Up to 3 marks.

• ✗Mistake: Wrong source of the Godavari; flow described as antecedent

  CISCE examiners' comments, 2025: candidates 'Gave Western Ghats/Nashik as place of origin of Godavari rather than its actual source' and 'Described nature of flow as antecedent and consequent'.

  ✓Do this: Source: Trimbakeshwar (Nashik district). Nature of flow: perennial or seasonal.

  Usually costs: 1-2 marks.

• ✗Mistake: Naming Deccan or Malwa for the whole Peninsular Plateau; mixing features with significance

  CISCE examiners' comments, 2024: candidates 'Wrongly identified the Peninsular Plateau as Deccan or Malwa Plateau' and 'Confused significance with characteristic features'.

  ✓Do this: Identify the whole block; write features and significance under separate headings.

  Usually costs: Up to 2 marks.

Practice questions on Structure of India – Geological Formation, Relief and Drainage

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

1. Q1 · 1 mark · Very short answerBoard level

   Name the source of the Narmada.

   Hint

   A plateau in Madhya Pradesh.

   Answer

   Amarkantak plateau.

2. Q2 · 1 mark · Very short answerBoard level

   What are duns?

   Hint

   Shiwaliks.

   Answer

   Longitudinal valleys between the Lesser Himalayas and the Shiwaliks, such as Dehradun.

3. Q3 · 1 mark · MCQHarder board level

   The Kumaon Himalayas lie between the rivers:
   (a) Indus and Sutlej
   (b) Sutlej and Kali
   (c) Kali and Tista
   (d) Tista and Dihang

   Hint

   Second division.

   Answer

   (b) Sutlej and Kali.

4. Q4 · 1 mark · Very short answerHarder board level

   Name the highest peak of the Western Ghats.

   Hint

   Kerala.

   Answer

   Anai Mudi (about 2,695 m).

5. Q5 · 2 marks · Short answerBoard level

   [2] Explain the evolution of the Peninsular Plateau.

   Hint

   Gondwana, drift, lava, faulting.

   Answer

   It is a part of the ancient Gondwanaland made of Precambrian crystalline rocks, which drifted north after Gondwanaland broke up; lava flows (Deccan Trap) covered its north-west, faulting formed rift valleys, and long erosion wore it into a low plateau.

6. Q6 · 3 marks · Short answerHarder board level

   [3] Compare the Western and Eastern Himalayas on three points.

   Hint

   Rise, rainfall, vegetation.

   Answer

   (1) The Western Himalayas rise gradually and are wider; the Eastern Himalayas rise abruptly and are narrower. (2) The Western Himalayas are drier; the Eastern Himalayas get very heavy rain. (3) The Western Himalayas have coniferous forests and alpine meadows; the Eastern have dense evergreen and broad-leaved forests.

7. Q7 · 4 marks · Short answerHOTS / competency

   [4] Why do the west-flowing Narmada and Tapi form estuaries and not deltas? Analyse.

   Hint

   Rift valleys, hard rocks, tides, slope.

   Answer

   (1) They flow through narrow rift valleys and carry relatively little sediment over hard rocks. (2) They flow into the Arabian Sea along a steep coast. (3) Strong tides and currents at their mouths carry away silt. (4) So silt does not accumulate into deltas, and their mouths remain open estuaries.

8. Q8 · 4 marks · Short answerHOTS / competency

   [4] Give four reasons why the Himalayan rivers are perennial and suitable for irrigation in the plains.

   Hint

   Glaciers, monsoon, plains, canals.

   Answer

   (1) They are fed by melting glaciers and snow in summer as well as by monsoon rain, so they flow throughout the year. (2) Their large catchments collect a great deal of water. (3) On entering the flat plains they slow down, making it easy to take canals from them. (4) The soft alluvium allows canals to be dug easily, so they support extensive canal irrigation.

9. Q9 · 7 marks · Long answerHOTS / competency

   [7] (a) Describe the Peninsular Plateau with reference to the Malwa, Chotanagpur and Deccan plateaus. [4]
   (b) Explain the formation of badlands with an example. [3]

   Hint

   (a) location, rocks, features; (b) gully erosion.

   Answer

   (a) The Peninsular Plateau is a triangular block of old rocks, 600-900 m high, sloping eastwards. The Malwa plateau lies between the Aravallis and Vindhyas, covered by lava and black soil and drained by the Chambal. The Chotanagpur plateau in Jharkhand is rich in coal, iron ore and mica and is drained by the Damodar. The Deccan plateau lies south of the Satpuras between the Ghats, with basalt in the north-west. (b) Badlands form when running water cuts soft soil into deep gullies and ravines, especially where vegetation is removed and rain falls in heavy bursts; the Chambal valley is an example, where the land is unfit for farming.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1. 1.What is the Deccan Trap?Show answer

   Basalt lava flows that covered the north-west Deccan at the end of the Cretaceous.

2. 2.Where does the Brahmaputra rise?Show answer

   Chemayungdung glacier near Lake Mansarovar, Tibet.

3. 3.Which hills form the Purvanchal?Show answer

   Patkai Bum, Naga hills, Manipur hills and Mizo hills.

4. 4.Name two lagoons on the east coast.Show answer

   Chilika and Pulicat.

5. 5.What is khadar?Show answer

   New alluvium on floodplains, renewed every year; very fertile.

Quick revision checklist

The night before the exam: can you do each of these without looking?

• ☐Peninsula: Gondwana, Precambrian, stable, lava and faulting, worn down.
• ☐Himalayas: Tethys sediments folded as Indian plate met Eurasian plate; still rising.
• ☐Plains: foredeep filled with Quaternary alluvium.
• ☐Himalayas: Greater, Lesser, Shiwaliks; Trans-Himalaya (Karakoram); Purvanchal; Punjab, Kumaon, Nepal, Assam divisions.
• ☐Plains: bhabar, tarai, bhangar, khadar, doab; Rajasthan, Punjab, Ganga, Brahmaputra plains.
• ☐Plateau: Malwa, Chotanagpur, Deccan; badlands (Chambal); Western Ghats higher, continuous; Eastern Ghats lower, broken.
• ☐Coasts: west narrow with estuaries and kayals; east wide with deltas, Chilika and Pulicat.
• ☐Islands: Andaman-Nicobar (mountain, volcanic) vs Lakshadweep (coral).
• ☐Rivers: Himalayan perennial, long, gorges, deltas; Peninsular seasonal, shorter, shallow valleys, deltas or estuaries.

Structure of India – Geological Formation, Relief and Drainage: frequently asked questions