Structure and Physiography, Class 11 Geography (India: Physical Environment)

What Structure and Physiography is about

Weightage: This chapter is part of Unit II, Physiography, of India: Physical Environment, which carries 13 of the 70 theory marks in the school annual exam together with Drainage System. Map work carries a further 5 marks for each book.Source: CBSE Geography (029) syllabus 2026-27, Class XI course structure

Key concepts

The three geological divisions

NCERT section The Peninsular Block; The Himalayas and Other Peninsular Mountains; Indo-Ganga-Brahmaputra Plain

	Peninsular Block	Himalayas and other Peninsular mountains	Indo-Ganga-Brahmaputra plain
Rocks/structure	Very ancient gneisses and granites; rigid since the Cambrian	Young, weak, flexible; faults, folds, thrust plains	Alluvium 1,000-2,000 m deep
Origin	Part of the Indo-Australian plate; vertical movements and block faulting (rift valleys of Narmada, Tapi, Mahanadi; Satpura block mountains)	Tectonic; still under endogenic and exogenic forces	Geosynclinal depression, maximum development in the third phase of Himalayan formation, about 64 million years ago; filled by Himalayan and Peninsular rivers
Relief	Relict and residual mountains (Aravali, Nallamala, Javadi, Veliconda, Palkonda, Mahendragiri)	High, rugged ranges	Flat plains
Rivers	Shallow valleys, low gradients; east-flowing rivers form deltas (Mahanadi, Krishna, Kaveri, Godavari)	Fast, youthful: gorges, V-shaped valleys, rapids, waterfalls	Mature landforms

Boundary of the Peninsular Block: an irregular line from Kachchh along the western flank of the Aravali near Delhi, roughly parallel to the Yamuna and Ganga to the Rajmahal hills and Ganga delta. Extensions: Karbi Anglong and Meghalaya plateau (separated from the Chotanagpur plateau by the Malda fault, West Bengal) and Rajasthan (covered by desert). Part of the west coast is submerged.

Worked example

Why are Himalayan rivers in a youthful stage while Peninsular rivers have shallow valleys? (2 marks)

Try it first, then show the solutionSolution

1. The Himalayas are young, weak and still rising, so rivers cut down fast, forming gorges, V-shaped valleys, rapids and waterfalls.
2. The Peninsular Block is ancient and rigid with relict mountains, so its rivers flow over low gradients in shallow valleys.

Answer: Young rising mountains vs an old stable block with low gradients.

Physiography and the six divisions

NCERT section Physiography

Physiography of an area is the outcome of structure, process and stage of development.

Broad pattern: the north has a vast rugged expanse of mountain ranges, peaks, valleys and gorges; the south is a stable table land of dissected plateaus, denuded rocks and scarps; between them lies the vast north Indian plain.

Six physiographic divisions:

• Northern and North-eastern Mountains
• Northern Plain
• Peninsular Plateau
• Indian Desert
• Coastal Plains
• Islands

Worked example

What three things decide the physiography of an area? (1 mark)

Try it first, then show the solutionSolution

1. NCERT defines physiography as an outcome.
2. The outcome of structure, process and stage of development.

Answer: Structure, process and stage of development.

The Northern and North-eastern Mountains

NCERT section The Himalayas and Other Peninsular Mountains

Composition: the Himalayas and the north-eastern hills. The Himalayas are a series of parallel ranges: the Greater Himalayan range (Great Himalayas), and the Shiwalik, among others.

Orientation changes:

Region	Direction of ranges
North-western India	North-west to south-east
Darjiling and Sikkim	East-west
Arunachal Pradesh	South-west to north-east (NCERT prints 'southwest to the northwest')
Nagaland, Manipur, Mizoram	North-south

Size: the Great Himalayan (central axial) range is about 2,500 km long east-west; width 160-400 km north-south.

Significance: a strong, long wall between the subcontinent and Central and East Asia; not only a physical barrier but also a climatic, drainage and cultural divide.

Map items (mountains): Karakoram Range (far north, Ladakh); Garo-Khasi-Jaintia hills (Meghalaya; they belong to the Meghalaya plateau). Peaks: K2 (Karakoram), Kanchenjunga (Sikkim), Nanda Devi (Uttarakhand), Nanga Parbat (western Himalaya), Namcha Barwa (eastern end, near Arunachal Pradesh). Passes: Shipki La (Himachal Pradesh), Nathu La (Sikkim).

Worked example

In what ways are the Himalayas a 'divide' besides being a physical barrier? (2 marks)

Try it first, then show the solutionSolution

1. NCERT calls the Himalayas a climatic, drainage and cultural divide.
2. They block cold winds and trap monsoon rain (climate), separate river systems (drainage) and have separated cultures of South Asia from Central and East Asia (culture).

Answer: Climatic, drainage and cultural divide.

The Northern Plains

NCERT section Indo-Ganga-Brahmaputra Plain

Formation: alluvial deposits of the Indus, Ganga and Brahmaputra. Length about 3,200 km east-west; width 150-300 km; alluvium up to 1,000-2,000 m deep; general elevation 50-150 m above sea level (otherwise featureless).

Zones from north to south:

Zone	Width	Features
Bhabar	8-10 km	Along the Shiwalik foothills at the break of slope; rivers drop heavy rocks and boulders and sometimes disappear
Tarai	10-20 km	Streams re-emerge without defined channels, creating marshy, swampy land; luxuriant vegetation and varied wildlife
Bhangar	-	Old alluvium
Khadar	-	New alluvium

Mature fluvial landforms: sand bars, meanders, oxbow lakes, braided channels. The Brahmaputra plains have riverine islands and sand bars; periodic floods and shifting courses form braided streams. The river mouths form some of the world's largest deltas, e.g. the Sunderbans.

Water divide: Haryana and Delhi separate the Indus and Ganga systems. The Brahmaputra flows north-east to south-west, then turns about 90° south at Dhubri into Bangladesh.

Importance: fertile alluvium supports wheat, rice, sugarcane, jute and a large population.

Worked example

Why do rivers sometimes disappear in the Bhabar and re-emerge in the Tarai? (2 marks)

Try it first, then show the solutionSolution

1. At the break of slope along the Shiwalik foothills, rivers drop heavy boulders and coarse material; water sinks into this porous belt and the streams disappear.
2. Further south, in the Tarai, the water re-emerges without well-defined channels, creating marshy, swampy land.

Answer: Coarse Bhabar deposits swallow the water; it resurfaces in the swampy Tarai.

The Peninsular Plateau

NCERT section The Peninsular Block

Extent: an irregular triangle rising from 150 m above the river plains to 600-900 m. Outer limits: Delhi ridge (north-west, Aravali extension), Rajmahal hills (east), Gir range (west), Cardamom hills (south); north-eastern extension: Shillong and Karbi Anglong plateau. One of the oldest and most stable landmasses; made of patland plateaus (Hazaribagh, Palamu, Ranchi, Malwa, Coimbatore, Karnataka). General slope west to east, shown by river flow.

Features: tors, block mountains, rift valleys, spurs, bare rocky structures, hummocky hills, wall-like quartzite dykes (natural water storage sites); black soil in the west and north-west. Repeated uplift and submergence, faulting and fractures (the Bhima fault is seismically active). North-west: ravines of Chambal, Bhind and Morena.

Three groups:

Group	Key points
Deccan Plateau	Bordered by the Western Ghats (west), Eastern Ghats (east), Satpura, Maikal and Mahadeo hills (north). Western Ghats: Sahyadri (Maharashtra), Nilgiri hills (Karnataka, Tamil Nadu), Anaimalai and Cardamom hills (Kerala); higher and more continuous than the Eastern Ghats; average 1,500 m, rising north to south; Anaimudi (2,695 m), highest peak of the peninsula, on the Anaimalai hills, then Dodabetta (2,637 m) on the Nilgiris; source of most Peninsular rivers. Eastern Ghats: discontinuous, low, eroded by the Mahanadi, Godavari, Krishna and Kaveri; Javadi, Palconda, Nallamala, Mahendragiri. The two Ghats meet at the Nilgiri hills
Central Highlands	Bounded west by the Aravali; Satpura (scarped plateaus, 600-900 m) is the northern boundary of the Deccan, a classic relict mountain; extend to Jaisalmer under longitudinal dunes and barchans; metamorphic rocks (marble, slate, gneiss); elevation 700-1,000 m, sloping north and north-east; Yamuna's tributaries rise in the Vindhyan and Kaimur ranges; Banas is the only significant Chambal tributary from the Aravali; eastern extension: Rajmahal hills, south of which the Chotanagpur plateau holds large mineral reserves
North-eastern Plateau	Extension of the main plateau; a huge fault between the Rajmahal hills and the Meghalaya plateau, created by the plate's north-eastward push during Himalayan formation, was later filled by river deposits; Meghalaya (Garo, Khasi, Jaintia hills, named after tribes) and Karbi Anglong stand detached; rich in coal, iron ore, sillimanite, limestone, uranium; maximum south-west monsoon rain, highly eroded; Cherrapunji shows bare rock

Worked example

Compare the Western and Eastern Ghats on two points. (2 marks)

Try it first, then show the solutionSolution

1. Western Ghats are higher (average 1,500 m) and continuous; Eastern Ghats are low and discontinuous.
2. Most Peninsular rivers rise in the Western Ghats; the Eastern Ghats are cut through and eroded by the Mahanadi, Godavari, Krishna and Kaveri.

Answer: Western: high, continuous, source of rivers; Eastern: low, broken by rivers.

The Indian Desert

NCERT section The Indian Desert

• Lies north-west of the Aravali hills: the Great Indian Desert or Marusthali.
• Undulating land with longitudinal dunes and barchans; rainfall below 150 mm a year; arid with low vegetation.
• Under the sea in the Mesozoic era: evidence in the wood fossils park at Aakal and marine deposits around Brahmsar, near Jaisalmer (wood fossils about 180 million years old).
• The underlying rock is an extension of the Peninsular plateau, but the surface is carved by physical weathering and wind: mushroom rocks, shifting dunes, oases (mostly in the south).
• Two parts by slope: north towards Sindh, south towards the Rann of Kachchh.
• Rivers mostly ephemeral; the Luni in the south is significant; low rainfall and high evaporation make it a water-deficit region.
• Inland drainage: some streams end in a lake or playa; brackish water there is the main source of salt.

Worked example

What evidence shows that the Indian desert was once under the sea? (2 marks)

Try it first, then show the solutionSolution

1. Wood fossils at Aakal, about 180 million years old.
2. Marine deposits around Brahmsar near Jaisalmer, showing the region was under the sea in the Mesozoic era.

Answer: Aakal wood fossils and Brahmsar marine deposits.

The Coastal Plains

NCERT section Indo-Ganga-Brahmaputra Plain

	Western coastal plain	Eastern coastal plain
Type	Submerged (city of Dwaraka believed submerged)	Emergent
Width	Narrow; narrow in the middle, broader in north and south	Broader
Ports	Natural conditions for ports and harbours: Kandla, Mazagaon, JLN port (Nhava Sheva), Marmagao, Mangalore, Cochin	Fewer ports: continental shelf extends up to 500 km into the sea
Deltas	No deltas	Well-developed deltas: Mahanadi, Godavari, Krishna, Kaveri
Divisions	Kachchh and Kathiawar (Gujarat), Konkan (Maharashtra), Goan coast, Malabar (Karnataka and Kerala)	(Map list: Northern Circars, Coromandel)
Special	Malabar Kayals (backwaters): fishing, inland navigation, tourism; Nehru Trophy Vallamkali boat race at Punnamada Kayal, Kerala	-

Map items (coastal plains): Saurashtra (Kathiawar, Gujarat), Konkan (Maharashtra), North and South Kanara (Karnataka coast), Malabar (Kerala), Coromandel (Tamil Nadu), Northern Circars (Andhra Pradesh-Odisha).

Worked example

Legend says the ancient city of Dwaraka now lies under the sea off Gujarat. How does this fit the type of coast found in western India, and how is the eastern coast different? (2 marks)

Try it first, then show the solutionSolution

1. The western coastal plains are a submerged coast: the belief that Dwaraka, once on the mainland, is now under water illustrates this; submergence makes the plain narrow and good for natural ports.
2. The eastern coastal plain is broader and an emergent coast, with well-developed deltas and a continental shelf extending up to 500 km into the sea.

Answer: Western coast: submerged (Dwaraka under the sea), narrow with natural ports; eastern coast: emergent, broad, with deltas.

The Islands

NCERT section Indo-Ganga-Brahmaputra Plain

	Bay of Bengal (Andaman and Nicobar)	Arabian Sea (Lakshadweep and Minicoy)
Number	About 572 islands/islets	About 36 islands, 11 inhabited
Location	About 6°N-14°N, 92°E-94°E	About 8°N-12°N, 71°E-74°E; 220-440 km off Kerala
Origin	Elevated portions of submarine mountains; some small ones volcanic; Barren Island: India's only active volcano	Entirely coral deposits
Groups	Andaman (north) and Nicobar (south), separated by the Ten Degree Channel; principal islet groups: Ritchie's archipelago, Labyrinth island	Divided by the Nine Degree Channel: Amini island north, Cannanore island south; Minicoy largest (453 sq km)
Features	Peaks: Saddle Peak (North Andaman, 738 m), Mount Diavolo (515 m), Mount Koyob (460 m), Mount Thuiller (Great Nicobar, 642 m); coral deposits, beaches; convectional rain, equatorial vegetation	Storm beaches of unconsolidated pebbles, shingle, cobbles and boulders on the eastern seaboard

Worked example

A geologist finds coral rock on every island she visits in one group, but volcanic rock and steep peaks in the other. Which island groups are these, and what does each finding say about their origin? (2 marks)

Try it first, then show the solutionSolution

1. All-coral islands are Lakshadweep in the Arabian Sea, built entirely of coral deposits.
2. Volcanic rock and peaks point to the Andaman and Nicobar Islands, elevated parts of submarine mountains with some volcanic islands such as Barren Island.

Answer: Lakshadweep (coral origin); Andaman and Nicobar (raised submarine mountains, partly volcanic).

Structure and Physiography 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

• Geological Divisions of India, the Northern and North-eastern Mountains and the Northern Plains
• The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India

Structure and Physiography: key facts

Geological divisions

Peninsular Block	old, rigid
Himalayas and other mountains	young, flexible
Indo-Ganga-Brahmaputra plain	alluvial, 1,000-2,000 m

Plain's geosyncline maximum about 64 million years ago.

Physiography

Structure + process + stage of development

Six divisions.

Himalaya size

Great Himalayan range about 2,500 km long; width 160-400 km

Physical, climatic, drainage and cultural divide.

Northern plain zones

$Bhabar(8-10km)\to Tarai(10-20km)\to Bhangar(old)/Khadar(new)$

Plain 3,200 km long, 150-300 km wide, 50-150 m high.

Plateau heights

Plateau 600-900 m; Western Ghats average 1,500 m; Central Highlands 700-1,000 m

Anaimudi 2,695 m; Dodabetta 2,637 m.

Desert

Rainfall < 150 mm; Mesozoic sea; Aakal wood fossils about 180 million years

Luni river; inland drainage to playas.

Coasts

West: submerged, narrow, ports, no deltas | East: emergent, broad, deltas, shelf up to 500 km, fewer ports

Kayals on Malabar coast.

Islands

A&N: 572, 6°-14°N, 92°-94°E, Ten Degree Channel | Lakshadweep: 36 (11 inhabited), 8°-12°N, 71°-74°E, Nine Degree Channel

Barren Island active volcano; Minicoy largest (453 sq km).

River gradient

$Gradient=fallinheight÷horizontaldistance$

Himalayan rivers steep; Peninsular rivers low gradient.

Structure and Physiography: diagrams to practise

Practise each one on paper: draw it from the checklist, then tick off every label.

Structure and Physiography: map work

The places on the official CBSE map list for this chapter. Find each one on an outline map of India and practise marking it.

How the school exam asks Structure and Physiography

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

Tricks to remember Structure and Physiography

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

• Six divisions

  'My New Pen Draws Coastal Islands': Mountains, Northern plains, Peninsular plateau, Desert, Coastal plains, Islands.

  Use it when: Physiographic divisions.

• Plain zones

  'Boys Take Big Kites': Bhabar, Tarai, Bhangar, Khadar (north to south).

  Use it when: Northern plain zones.

• Peaks on the map

  'K-K-N-N-N-A': K2, Kanchenjunga, Nanda Devi, Nanga Parbat, Namcha Barwa, Anaimudi.

  Use it when: Map peaks.

• West coast divisions

  'Kids Kick Goals Mightily': Kachchh-Kathiawar, Konkan, Goa, Malabar.

  Use it when: West coast divisions.

• Island numbers

  '572 east, 36 west (11 live)'.

  Use it when: Island groups.

Structure and Physiography: exam-level solved questions

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

Case-study practice (Section E style)

Read the situation, then answer every part. In a school exam set on the board pattern this is a 4-mark question split into 1 + 1 + 2 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 and Physiography

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

• ✗Mistake: Calling the western coast emergent

  Swapping coast types.

  Wrong working

  The west coast is emergent and has deltas.

  Right working

  The west coast is submerged (narrow, natural harbours, no deltas); the east coast is emergent (broad, deltas).

  ✓Do this: West went under (Dwaraka).

  Usually costs: 1-2 marks.

• ✗Mistake: Reversing Bhabar and Tarai

  Both are foothill belts.

  Wrong working

  Rivers disappear in the Tarai and re-emerge in the Bhabar.

  Right working

  Rivers disappear in the Bhabar (boulders) and re-emerge in the Tarai (marshy).

  ✓Do this: B before T, from the hills down: Boulders, then Tarai's water.

  Usually costs: 1 mark.

• ✗Mistake: Giving Dodabetta as the highest peninsular peak

  Both peaks are in the south.

  Wrong working

  Dodabetta (2,637 m) is the highest peak of the peninsula.

  Right working

  Anaimudi (2,695 m) on the Anaimalai hills is highest; Dodabetta is second.

  ✓Do this: A before D.

  Usually costs: 1 mark.

• ✗Mistake: Swapping the Ten and Nine Degree Channels

  Similar names.

  Wrong working

  The Nine Degree Channel separates Andaman from Nicobar.

  Right working

  Ten Degree Channel: Andaman-Nicobar. Nine Degree Channel: within Lakshadweep.

  ✓Do this: Ten for the Bay (bigger group), Nine for the Arabian Sea.

  Usually costs: 1 mark.

• ✗Mistake: Misplacing passes on the map

  Western Ghats passes are less familiar.

  Wrong working

  Palghat marked in Maharashtra.

  Right working

  Palghat: Kerala-Tamil Nadu gap in the Western Ghats; Bhor Ghat and Thal Ghat: Western Ghats near Mumbai; Shipki La: Himachal; Nathu La: Sikkim.

  ✓Do this: Two Himalayan, three Western Ghats.

  Usually costs: 1 map mark each.

NCERT exercise guide: Structure and Physiography

What each exercise in the NCERT chapter tests, how to approach it, and a question of the same kind solved step by step. Questions here are written in our own words.

Practice questions on Structure and Physiography

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 · MCQExam level

   On which hill range is Dodabetta?
   (a) Nilgiri
   (b) Anaimalai
   (c) Cardamom
   (d) Nallamala

   Hint

   Second highest after Anaimudi.

   Answer

   (a) Nilgiri hills.

2. Q2 · 1 mark · MCQExam level

   Which is the only active volcano in India?
   (a) Saddle Peak
   (b) Barren Island
   (c) Mount Thuiller
   (d) Narcondam

   Hint

   In the Andaman and Nicobar group.

   Answer

   (b) Barren Island.

3. Q3 · 1 mark · Assertion-reasonHarder exam level

   Assertion (A): The Satpura is a relict mountain.
   Reason (R): It is highly denuded and forms discontinuous ranges.
   Choose (a)-(d).

   Hint

   NCERT calls it a classic example.

   Answer

   (a).

4. Q4 · 2 marks · Short answerExam level

   Distinguish between Bhangar and Khadar. (2 marks)

   Hint

   Old and new.

   Answer

   Bhangar is the old alluvium of the plains; Khadar is the new alluvium, laid on floodplains by recent floods. Both lie south of the Tarai.

5. Q5 · 2 marks · Short answerExam level

   Two peaks on the map list mark the two ends of the Himalayan system shown on the map: one in the Karakoram and one at the eastern end. Name them and say in which part of India or beyond each lies. (2 marks)

   Hint

   Karakoram; eastern bend.

   Answer

   K2 in the Karakoram range in the far north (Ladakh region) and Namcha Barwa at the eastern end, near Arunachal Pradesh, where the Himalaya bends sharply.

6. Q6 · 2 marks · Short answerHarder exam level

   Why is the general slope of the Peninsular plateau from west to east, and what evidence supports it? (2 marks)

   Hint

   Look at where rivers flow.

   Answer

   NCERT states the general elevation falls from west to east; the evidence is that most major Peninsular rivers (Mahanadi, Godavari, Krishna, Kaveri) rise in the Western Ghats and flow east into the Bay of Bengal.

7. Q7 · 3 marks · Short answerHOTS / competency

   Suppose a company wants to build a new deep-water port. Using the chapter, would you advise the west coast or the east coast? Give reasons. (3 marks)

   Hint

   Submerged versus emergent.

   Answer

   The west coast. It is a submerged, narrow coast that provides natural conditions for ports and harbours (Kandla, Mumbai, Marmagao, Mangalore, Cochin). The east coast is emergent with a continental shelf up to 500 km wide, making good ports difficult.

8. Q8 · 5 marks · Long answerHarder exam level

   Describe the three divisions of the Peninsular plateau. (5 marks)

   Hint

   Deccan, Central Highlands, North-eastern.

   Answer

   Deccan: between Western Ghats (high, continuous, 1,500 m, Anaimudi 2,695 m), Eastern Ghats (low, discontinuous) and Satpura-Maikal-Mahadeo; Ghats meet at the Nilgiris. Central Highlands: west of the plateau bounded by the Aravali; Satpura scarps (600-900 m); 700-1,000 m, sloping north and north-east; Vindhyan and Kaimur ranges; Chotanagpur minerals. North-eastern plateau: Meghalaya (Garo, Khasi, Jaintia) and Karbi Anglong, detached by a filled fault; minerals; heavy rain and erosion.

9. Q9 · 2 marks · Short answerHOTS / competency

   Why do the Brahmaputra plains have riverine islands and braided channels? (2 marks)

   Hint

   Floods and shifting courses.

   Answer

   The Brahmaputra plains are subject to periodic floods and shifting river courses; deposition of sand bars splits the flow into braided streams and builds riverine islands.

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 separates the Meghalaya plateau from the Chotanagpur plateau?Show answer

   The Malda fault in West Bengal.

2. 2.When did the Indo-Ganga-Brahmaputra geosyncline reach maximum development?Show answer

   In the third phase of Himalayan formation, about 64 million years ago.

3. 3.How long is the Great Himalayan range?Show answer

   About 2,500 km.

4. 4.Which states form the water divide between the Indus and Ganga systems?Show answer

   Haryana and Delhi.

5. 5.Where does the Brahmaputra take a 90° southward turn?Show answer

   At Dhubri.

6. 6.What is the only significant Chambal tributary rising in the Aravali?Show answer

   The Banas.

7. 7.Where are the Kayals found?Show answer

   On the Malabar coast of Kerala.

8. 8.Which is the largest island of Lakshadweep?Show answer

   Minicoy (453 sq km).

Quick revision checklist

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

• ☐Geological divisions: Peninsular Block (old, rigid), Himalayas and other mountains (young, flexible), Indo-Ganga-Brahmaputra plain (alluvium 1,000-2,000 m).
• ☐Physiography = structure + process + stage; six divisions.
• ☐Great Himalaya about 2,500 km long, 160-400 km wide; physical, climatic, drainage and cultural divide.
• ☐Northern Plains 3,200 km; Bhabar 8-10 km, Tarai 10-20 km, Bhangar old, Khadar new; Sunderbans delta.
• ☐Peninsular plateau 600-900 m; Deccan, Central Highlands, North-eastern plateau.
• ☐Western Ghats 1,500 m average, Anaimudi 2,695 m, Dodabetta 2,637 m; Ghats meet at the Nilgiris.
• ☐Indian desert: < 150 mm rain; Mesozoic sea; Aakal fossils; Luni; inland drainage.
• ☐West coast submerged, narrow, ports, no deltas; east coast emergent, broad, deltas, shelf 500 km.
• ☐A&N: 572 islands, Ten Degree Channel, Barren Island volcano; Lakshadweep: 36 coral islands, Nine Degree Channel.
• ☐Map: mountains, peaks, passes, plateaus, coastal plains, islands as listed.

Structure and Physiography: frequently asked questions