UPSC Prelims 2026 Q34: Peninsular Block Features — Explained
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
- 1 only
- 1 and 2
- 2 and 3
- 3 only
Answer: (b) 1 and 2
Statement-wise explanation
- 1: correct — NCERT (Class 11, India: Physical Environment, Ch. 2) says that since the Cambrian period the Peninsula has stood like a rigid block, except that some of its western coast was submerged beneath the sea and some other parts changed through tectonic activity. These changes did not affect the original basement. The same book calls the western coastal plain a submerged coastal plain and cites the legend of Dwaraka, believed to lie under the sea. So submergence of parts of the western coast is a known feature of the Peninsular Block.
- 2: correct — NCERT says the Peninsula 'mostly consists of relict and residual mountains like the Aravali hills, the Nallamala hills, the Javadi hills, the Veliconda hills, the Palkonda range and the Mahendragiri hills'. These are the worn-down stumps of very old ranges. The Veliconda hills are in Andhra Pradesh and the Mahendragiri hills are in Odisha, and both belong to the broken Eastern Ghats. The statement uses the same examples as the textbook.
- 3: incorrect — Right after naming the residual hills, NCERT says the river valleys of the Peninsula 'are shallow with low gradients'. Deep, V-shaped valleys and gorges cut by fast-flowing, actively eroding rivers belong to the young, still-rising Himalayas, not to the old, stable Peninsula. Peninsular rivers mostly flow in mature, broad, graded valleys.
How to eliminate
The question comes almost word for word from one paragraph of NCERT Class 11, Ch. 2. Basic logic also gets you there. The Peninsula is the oldest and most stable landmass in India, and its rivers are old and mature. 'Deep, V-shaped valleys formed by fast-flowing rivers' describes young rivers cutting down hard into rising land. That is the textbook contrast between the Himalayas and the Peninsula, so Statement 3 should be dropped first. Dropping it rules out every option except '1 only' and '1 and 2'. Words like 'residual' and 'relict' belong to old, eroded landscapes, so Statement 2 fits the Peninsula, and that leaves '1 and 2'. Statement 1 can look odd, because a 'stable' block with 'tectonic activity' sounds like a contradiction. The fact to remember is NCERT's exception: the rigid block was affected only at its edges, including the submerged western coast.
Know more
The Peninsular Block is the oldest and most stable part of India. It is made mostly of Precambrian gneisses and granites. NCERT traces its northern boundary as an irregular line from Kachchh, along the western flank of the Aravalis, near Delhi, roughly parallel to the Yamuna and Ganga up to the Rajmahal hills and the Ganga delta. The Karbi Anglong and Meghalaya plateaus in the north-east are extensions of the block.
Rigid, but not untouched. Since the Cambrian period it has behaved as a rigid block. Movement has happened only at its edges. Part of the western coast was submerged, and faulting formed rift valleys such as those of the Narmada and Tapi and the Gondwana coal basins. The original basement stayed intact.
Relict landscape. Long erosion has reduced old ranges to residual hills: the Aravalis, Nallamala, Javadi, Veliconda, Palkonda and Mahendragiri. Rivers have reached a mature stage, with shallow, low-gradient valleys.
| Feature | Peninsular Block | Himalayas |
|---|---|---|
| Age and stability | Oldest; rigid and stable | Young fold mountains; still rising, quake-prone |
| Rocks | Igneous and metamorphic (gneiss, granite) | Folded sedimentary and metamorphic |
| Relief | Relict and residual hills, plateaus | High, sharp ranges |
| River valleys | Shallow, broad, low gradient | Deep, V-shaped valleys and gorges |
| Rivers | Mostly rain-fed, seasonal | Snow- and rain-fed, perennial |
| Coast link | Submerged west coast, emergent east coast | — |
UPSC often turns this Himalaya-versus-Peninsula contrast into statement questions. Learn the NCERT paragraph closely, including the named hill examples.
NCERT Concepts to Revise
- Peninsular Block: Statements 1 and 2 test what NCERT says about the Peninsular Block, a rigid landmass since the Cambrian period, including its western coast and residual hills.
- Relict mountain: Statement 2 depends on knowing that relict or residual mountains, like the Veliconda and Mahendragiri hills, are worn-down stumps of very old ranges.
- Geological divisions of India: Statement 3 asks you to tell apart features of the stable Peninsula from those of the young Himalayas, using India's geological divisions.
- Himalayan orogeny: Statement 3 describes deep V-shaped valleys cut by fast rivers, so knowing how the young, still-rising Himalayas formed helps place that feature.
- Eastern Ghats: Statement 2 names the Veliconda hills of Andhra Pradesh and the Mahendragiri hills of Odisha, both parts of the broken Eastern Ghats.