Authentic Classroom Explanation by IAS Monk

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📍 The Question

Gandikota Canyon of South India was created by which one of the following rivers?

(a) Cauvery
(b) Manjira
(c) Pennar
(d) Tungabhadra

Correct Answer: (c) Pennar

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🎯 Theme of the Question

Indian Geography | Geomorphology | River Erosion | Canyons & Gorges

This question tests knowledge of river-carved landforms in Peninsular India, especially lesser-known but visually striking features.

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🧠 Classroom Explanation

• Gandikota is a historic village and fort located in Kadapa district, Andhra Pradesh
• It is often called the “Grand Canyon of India”
• The canyon has been carved by fluvial erosion over long geological time

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🌊 Role of the Pennar River

• The Pennar River flows through the Eastern Deccan Plateau
• Near Gandikota:
  • The river cuts through hard quartzite and sandstone
  • Continuous vertical erosion formed a deep, narrow gorge (canyon)
• The fort of Gandikota stands dramatically on the edge of this canyon

✔️ Hence, Pennar River is responsible for the formation of Gandikota Canyon.

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❌ Why other options are incorrect

• Cauvery ❌
  • Known for waterfalls and deltaic features, not Gandikota
• Manjira ❌
  • Tributary of Godavari, no canyon formation here
• Tungabhadra ❌
  • Known for Hampi region and floodplains, not Gandikota

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📊 Final Assessment

River	Associated Feature
Cauvery	Waterfalls, delta
Manjira	Godavari basin
Pennar	Gandikota Canyon ✅
Tungabhadra	Hampi plains

👉 Correct answer: (c) Pennar

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🧩 Memory Hook

“Gandikota cuts deep — Pennar carved it.”

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🧠 Prelims Strategy Insight

For canyon/gorge questions in India:

• Mostly found in peninsular hard-rock regions
• Associate:
  • River name + district/state
• Gandikota = Pennar + Andhra Pradesh

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🧭 IAS Monk Whisper

Even quiet rivers, given time, can carve monuments in stone.

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📌 Enrichment: Famous Canyons & Canyon-like Landscapes

🌄 Grand Canyon of the USA

• Carved by the Colorado River over nearly 5–6 million years
• One of the deepest and most extensive gorges in the world
  • Length: ~446 km
  • Depth: over 1.6 km
• Exposes nearly 2 billion years of Earth’s geological history in its rock layers
• A classic example of:
  • Vertical river erosion
  • Long-term fluvial incision in an uplifted plateau (Colorado Plateau)
• Demonstrates how:
  • Slow-moving rivers + immense geological time can create dramatic landforms

🧠 Concept link for UPSC:
River rejuvenation, plateau uplift, fluvial geomorphology.

🌍 Deepest Canyon in the World

🏔️ Yarlung Tsangpo (Tsangpo) Grand Canyon

• Location: Tibet–Arunachal Pradesh region
• Carved by: Yarlung Tsangpo River (becomes the Brahmaputra in India)
• Depth: ~5,300–6,000 metres
  👉 Almost 3 times deeper than the Grand Canyon
• Formed due to:
  • Rapid tectonic uplift of the Himalayas
  • Extremely powerful river incision

🧠 UPSC angle:
Tectonics + fluvial erosion, Himalayan geomorphology.

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🌎 Widest Canyon (General Understanding)

• Grand Canyon (USA) is among the widest, but:
  • Width varies from 6 km to 29 km
  • It is not officially the widest in absolute terms
• Some canyons and gorges elsewhere exceed it locally in width, but:
  • They lack the continuous length + depth + exposure of the Grand Canyon

👉 So in exams and textbooks:

• Grand Canyon = largest / most extensive / most famous
• Not the deepest

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🏜️ Where the Grand Canyon Actually Stands

Parameter	Status
Deepest canyon	❌ No
Widest canyon	❌ Not strictly
Longest canyon	❌ No
Most studied & iconic	✅ Yes
Best exposed geological history	✅ Yes (≈2 billion years)

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🧠 One-Line Exam-Ready Takeaway

• Deepest canyon: Yarlung Tsangpo Grand Canyon
• Grand Canyon: World’s most famous and geologically illustrative canyon, not the deepest

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🧭 IAS Monk Whisper

Fame belongs to the Grand Canyon; depth bows to the Himalayas.

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🧨 One-Line Prelims Trap Note

👉 Grand Canyon is the most famous and geologically illustrative canyon of the world, but the deepest canyon is the Yarlung Tsangpo (Brahmaputra) Grand Canyon, not the Grand Canyon.

(UPSC often tests fame vs fact.)

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✍️ GS-I Mains Enrichment Paragraph (2–3 lines)

The Grand Canyon of the USA, carved by the Colorado River, is renowned for its exceptional exposure of nearly two billion years of Earth’s geological history, making it the world’s most studied canyon. However, the deepest canyon globally is the Yarlung Tsangpo Grand Canyon, formed by intense fluvial erosion combined with rapid tectonic uplift in the Himalayan region. This contrast highlights the interplay of endogenic and exogenic forces in shaping major landforms.

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🧭 IAS Monk Whisper

Not the loudest landform is the deepest — geography rewards precision, not popularity.