UPSC Prelims 2026Question 34Geography

Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India ?
1. Submergence of parts of the western coast due to tectonic activity
2. Presence of residual mountain ranges such as the Veliconda hills and Mahendragiri hills
3. Deep, V-shaped river valleys formed by fast-flowing rivers
Select the answer using the code given below:

Options

(a)1 only
(b)1 and 2
(c)2 and 3
(d)3 only

Correct answer: b

Decision rule

Match landform to crustal age: deep V-shaped valleys belong to young fold mountains; old stable plateaus carry broad, graded, mature valleys.

Explanation

Correct Answer

(b) 1 and 2

Explanation of the Correct Answer

Statement 1: Submergence of parts of the western coast due to tectonic activity

Correct.

The Peninsular Block of India is an ancient and relatively stable landmass, but its margins have been affected by tectonic movements.
The western coast shows evidence of submergence, leading to the formation of:
- estuaries,
- natural harbours,
- narrow coastal plains,
- indented coastline in some areas.
The submergence of parts of the western coast is linked with tectonic movements associated with the evolution of the Peninsular Block and the Arabian Sea margin.

Hence, statement 1 is correct.

Statement 2: Presence of residual mountain ranges such as the Veliconda hills and Mahendragiri hills

Correct.

The Peninsular Block contains several residual hills and ancient mountain ranges.
These are remnants of old fold mountains and uplands that have been greatly worn down by denudation.
Examples include:
- Aravalli Range
- Nallamala Hills
- Veliconda Hills
- Javadi Hills
- Mahendragiri Hills
- Western Ghats and Eastern Ghats

Therefore, statement 2 is correct.

Statement 3: Deep, V-shaped river valleys formed by fast-flowing rivers

Incorrect.

Deep, narrow, V-shaped valleys are mainly associated with young fold mountains, such as the Himalayas, where rivers are fast-flowing and actively eroding vertically.
The Peninsular rivers generally flow over an old, stable, hard-rock plateau.
They are comparatively mature rivers and usually form:
- broad and shallow valleys,
- graded profiles,
- waterfalls at escarpments,
- gorges in some places, but not widespread deep V-shaped youthful valleys.

Hence, statement 3 is not a general feature of the Peninsular Block.

Therefore, only statements 1 and 2 are correct.

Why Other Options Are Incorrect

Option	Verdict	Explanation
(a) 1 only	Incorrect	Statement 1 is correct, but statement 2 is also correct because the Peninsular Block has residual ranges such as Veliconda and Mahendragiri hills.
(b) 1 and 2	Correct	Both submergence of parts of the western coast and residual mountain ranges are associated with the Peninsular Block.
(c) 2 and 3	Incorrect	Statement 2 is correct, but statement 3 is incorrect because deep V-shaped valleys are more typical of youthful Himalayan rivers, not mature Peninsular rivers.
(d) 3 only	Incorrect	Statement 3 is incorrect as a general characteristic of the Peninsular Block.

Relevant Supplementary Information

Peninsular Block of India: Key Geographical Features

Feature	Details
Geological nature	Ancient, stable, hard-rock landmass
Tectonic character	Relatively stable compared to the Himalayas
Major rocks	Igneous, metamorphic and old crystalline rocks
Relief type	Plateau, residual hills, escarpments and dissected uplands
Important ranges	Aravalli, Vindhyan, Satpura, Western Ghats, Eastern Ghats
Residual hills	Veliconda, Nallamala, Javadi, Mahendragiri
Western coast	Partly submerged coast; narrow coastal plain
Eastern coast	More emergent coast; broader coastal plain and deltas
River character	Older, mature rivers with broad valleys
Examples of rivers	Godavari, Krishna, Kaveri, Narmada, Tapi, Mahanadi

Western Coast vs Eastern Coast of Peninsular India

Basis	Western Coast	Eastern Coast
Nature	Largely submerged coast	Largely emergent coast
Width	Narrow coastal plain	Broad coastal plain
Rivers	Short, swift west-flowing rivers	Long east-flowing rivers
Delta formation	Limited delta formation	Large deltas common
Examples of deltas	Generally absent or small	Godavari, Krishna, Kaveri, Mahanadi
Harbours	More natural harbours	Fewer natural harbours
Associated sea	Arabian Sea	Bay of Bengal

Basis	Western Coast	Eastern Coast
Nature of coast	Largely submerged coast	Largely emergent coast
Width	Narrow	Broad
Main sea/ocean side	Arabian Sea	Bay of Bengal
Mountain proximity	Western Ghats run close to the coast	Eastern Ghats are discontinuous and farther from the coast
Rivers	Short and swift west-flowing rivers	Long east-flowing rivers
Delta formation	Limited	Extensive
Estuaries	Common	Less prominent than deltas
Natural harbours	More favourable	Comparatively fewer
Major examples	Konkan, Karnataka coast, Malabar coast	Northern Circars, Coromandel coast
Important rivers	Narmada, Tapi, Mandovi, Zuari, Periyar	Mahanadi, Godavari, Krishna, Kaveri

Peninsular Rivers vs Himalayan Rivers

Feature	Peninsular Rivers	Himalayan Rivers
Geological setting	Old, stable plateau	Young fold mountains
River stage	Mostly mature	Mostly youthful in upper courses
Valleys	Broad, shallow valleys; gorges in some areas	Deep, narrow V-shaped valleys in upper courses
Flow pattern	Mostly seasonal, rain-fed	Perennial, snow-fed and rain-fed
Erosion type	More lateral erosion and denudation	Strong vertical erosion in upper reaches
Examples	Godavari, Krishna, Kaveri, Narmada	Indus, Ganga, Brahmaputra

Feature	Peninsular Rivers	Himalayan Rivers
Terrain	Old, hard-rock plateau	Young fold mountain region
River stage	Mostly mature	Youthful in upper courses
Valley type	Broad, shallow valleys; gorges in some areas	Deep, narrow V-shaped valleys in upper courses
Source	Mostly rain-fed	Snow-fed and rain-fed
Flow nature	More seasonal	Mostly perennial
Erosional activity	Less vertical erosion, more lateral erosion in mature stages	Strong vertical erosion in mountains
Drainage pattern	Superimposed, radial, trellis and dendritic patterns	Antecedent and dendritic patterns
Floodplain development	Less extensive than northern plains	Very extensive in Indo-Gangetic plains
Examples	Godavari, Krishna, Kaveri, Narmada, Tapi	Indus, Ganga, Yamuna, Brahmaputra

Key Takeaways from the Tables

Point	Explanation
Peninsular Block is ancient and stable	It consists mainly of old crystalline rocks and has undergone long denudation.
Western coast shows submergence	This explains its narrow coastal plain and better natural harbours.
Eastern coast is more emergent	This explains its wider coastal plain and large river deltas.
Residual hills are common	Veliconda and Mahendragiri hills are examples of denuded residual ranges.
V-shaped valleys are not typical	They are more characteristic of youthful Himalayan rivers than mature Peninsular rivers.

Point	Explanation
Peninsular Block is old and stable	It is made mainly of ancient crystalline rocks and has undergone long denudation.
Western coast is submerged	This explains its narrow coastal plains, estuaries and better natural harbours.
Eastern coast is emergent	This explains its wider coastal plains and large deltas.
Residual hills are important	Veliconda, Mahendragiri, Javadi and Nallamala hills are examples of old denuded features.
Deep V-shaped valleys are not typical	They are mainly associated with youthful Himalayan rivers, not mature Peninsular river systems.
Narmada and Tapi are exceptions	They flow westwards through rift valleys, unlike most Peninsular rivers that flow eastwards.

Context and Current Relevance

The Peninsular Block forms the geological core of India and influences drainage, minerals, soils and relief patterns.
Its ancient hard-rock terrain is important for understanding plateau landscapes, mineral belts and river basin planning.
Coastal submergence and emergence remain relevant for studying coastal geomorphology, ports, erosion and climate-related sea-level risks.

Table: Peninsular Block of India — Major Geographical Features

Feature	Description	Examples / Significance
Geological nature	Ancient, stable landmass made mainly of old crystalline, igneous and metamorphic rocks	Forms the geological core of India
Age	One of the oldest landmasses of India	Part of the ancient Gondwana landmass
Relief	Plateau-dominated relief with residual hills, escarpments and dissected uplands	Deccan Plateau, Chotanagpur Plateau, Malwa Plateau
Tectonic stability	Relatively stable compared to the Himalayas	However, block faulting and coastal changes have occurred
Western coast	Partly submerged coast	Narrow coastal plain, estuaries, natural harbours
Eastern coast	Comparatively emergent coast	Broad coastal plain, large deltas
Mountain ranges	Old residual ranges and plateau margins	Aravalli, Vindhya, Satpura, Western Ghats, Eastern Ghats
Residual hills	Remnants of old denuded mountain systems	Veliconda Hills, Mahendragiri Hills, Javadi Hills, Nallamala Hills
Drainage pattern	Mostly mature river systems	Godavari, Krishna, Kaveri, Mahanadi
River valleys	Generally broad and shallow valleys; gorges in some areas	Not typically deep V-shaped valleys like Himalayan rivers
Mineral wealth	Rich in metallic and non-metallic minerals	Iron ore, manganese, bauxite, coal, mica
Soils	Diverse soil types due to varied rocks and climate	Black soil, red soil, laterite soil

Table: Important Residual Hills and Ranges of the Peninsular Block

Hill / Range	Location	Associated Region	Important Point
Aravalli Range	Rajasthan, Haryana, Gujarat, Delhi region	Northwestern Peninsular Block	One of the oldest fold mountain systems in India
Vindhyan Range	Central India	North of Narmada valley	Forms a major escarpment-like feature
Satpura Range	Madhya Pradesh, Maharashtra region	Between Narmada and Tapi valleys	Important central Indian range
Western Ghats	Western edge of Deccan Plateau	Parallel to Arabian Sea coast	Steep escarpment; important biodiversity hotspot
Eastern Ghats	Eastern edge of Peninsular India	Odisha to Tamil Nadu	Discontinuous and highly eroded
Nallamala Hills	Andhra Pradesh, Telangana	Eastern Ghats system	Associated with the Krishna river basin
Veliconda Hills	Andhra Pradesh	Eastern Ghats system	Residual hills of the Peninsular Block
Mahendragiri Hills	Odisha-Andhra region	Eastern Ghats	Important peak in the Eastern Ghats
Javadi Hills	Tamil Nadu	Eastern Ghats	Residual hill range in northern Tamil Nadu
Shevaroy Hills	Tamil Nadu	Eastern Ghats	Known for Yercaud region

Table: Similar Prelims-Trap Facts on Peninsular India

Statement / Theme	Correct Understanding	Common Trap
Western coast	Largely submerged coast	Assuming both coasts are similar
Eastern coast	Largely emergent coast	Ignoring its broad plains and deltas
Peninsular rivers	Mostly mature rivers	Assuming they form deep V-shaped valleys everywhere
V-shaped valleys	Typical of youthful rivers in mountains	Applying Himalayan features to Peninsular rivers
Residual hills	Common in Peninsular India	Treating all hills as young fold mountains
Western Ghats	Escarpment-like plateau edge	Calling them young fold mountains
Eastern Ghats	Discontinuous and highly denuded	Treating them as continuous like Western Ghats
Narmada and Tapi	Flow through rift valleys westwards	Assuming all Peninsular rivers flow eastwards
Deltas	More common on the eastern coast	Expecting large deltas on the western coast
Natural harbours	More favourable on the western coast	Assuming eastern coast has more due to wider plain

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Class 11Structure and Physiography — NCERT Geography, Chapter 2. India's landforms come from its geological history. Three geological divisions follow the relief: the rigid, ancient Peninsular Block of gneiss and granite; the young…