Unit 6.1: Conventional: Coal, Oil & Gas Basins
Indian Geography ā Indian Geography ā RESOURCES & ECONOMIC GEOGRAPHY ā RESOURCES & ECONOMIC GEOGRAPHY ā Energy Systems | Author: admin | Feb 11, 2026
1. Introduction This unit focuses on India's conventional energy resources ā coal, petroleum (oil), and natural gas ā and their major sedimentary basins. Coal dominates India's energy mix (Gondwana and Tertiary fields), while oil and gas are concentrated in specific basins (onshore and offshore). These resources drive power generation, transport, and industry, but face challenges of depleting reserves, import dependence, and environmental concerns. The unit covers basin distribution, major fields, production, and economic significance.
2. Significance This unit is crucial for 2026 exams ā it carries 6ā10 marks in Prelims (MCQs on basins, states, major fields) and 8ā12 marks in Mains (analytical on energy security, import dependence, transition to renewables). SSC/RRB/JE test factual recall (coal fields, basins); State PSC focus on state-level production. Linkages to current: Coal production push (2025ā2026), KG basin gas discoveries, energy transition under NAPCC, import data (oil ~85%, gas ~50%). Master this for high scores in GS3 (energy, economy, environment).
3. Chronological/Geological Timeline
- Gondwana period (~300ā250 Ma): Major coal deposits formed in peninsular basins.
- Tertiary period (~65ā2 Ma): Younger coal (lignite) and oil-gas basins form.
- 19th century: Coal mining begins in Raniganj (British era).
- 1950sā1960s: ONGC formed (1956); oil discoveries in Cambay, Ankleshwar.
- 1970sā1980s: Bombay High offshore oil (1974); coal nationalization (1973).
- 2000sā2010s: KG basin gas (2002 Reliance); CBM (coal bed methane) development.
- 2020sā2026: KG-D6 gas revival; coal production target 1.5 billion tonnes; energy security focus.
4. Concept Deep Dive Coal: Gondwana (high grade, bituminous) in peninsular basins; Tertiary (lignite) in Gujarat, Rajasthan, TN. Oil & Gas: Sedimentary basins with source rock, reservoir, trap. Major basins: Mumbai High (offshore), KG (Krishna-Godavari), Cambay, Assam-Arakan, Cauvery. Production: Coal ~80% of power; oil ~15% domestic (85% import); gas ~50% domestic. (Ref: NCERT Class 10 Contemporary India Ch. 5 "Minerals & Energy"; Majid Husain Ch. 6 "Energy Resources"; Savindra Singh Ch. 14 "Mineral & Energy Deposits"; Oxford Atlas for basin maps).
5. Key Terminology Box
- Gondwana Coal: Ancient (Permian), high-grade bituminous coal in peninsular basins.
- Tertiary Coal: Younger lignite in western/southern India.
- Sedimentary Basin: Depression with oil/gas source rock, reservoir, trap.
- Mumbai High: Offshore oil field (Arabian Sea).
- KG Basin: Krishna-Godavari basin (onshore-offshore, major gas).
- CBM (Coal Bed Methane): Gas extracted from coal seams.
- ONGC: Oil and Natural Gas Corporation (public sector).
- Reliance KG-D6: Major private gas field.
6. Important Factual Details
| Resource | Major Basins / Fields | States / Locations | Production / Importance (2026) |
|---|---|---|---|
| Coal (Gondwana) | Damodar Valley, Singareni, Talcher, Korba | Jharkhand, Odisha, Chhattisgarh, MP, WB | ~80% power; 1.5 billion tonnes target |
| Coal (Tertiary) | Neyveli, Kutch, Rajasthan | Tamil Nadu, Gujarat, Rajasthan | Lignite for power |
| Oil | Mumbai High, KG Basin, Cambay, Assam | Offshore Maharashtra, AP, Gujarat, Assam | ~15% domestic; 85% import |
| Natural Gas | KG-D6, Mumbai High, Tripura, Cauvery | AP, Maharashtra offshore, Tripura, TN | ~50% domestic; fertilizer, power |
| CBM | Jharia, Raniganj, Sohagpur | Jharkhand, West Bengal, MP | Emerging unconventional source |
7. Frequently Asked Exam Facts
- Coal: Gondwana (high grade), Tertiary (lignite).
- Largest coal basin: Damodar Valley (Jharkhand-WB).
- Mumbai High: Offshore oil (Arabian Sea).
- KG Basin: Major gas field (Reliance KG-D6).
- Singareni: Telangana coal belt.
- Neyveli: Tamil Nadu lignite field.
- Assam: Oldest oil field (Digboi).
- Coal nationalized: 1973.
- Oil import: ~85%.
- Gas import: ~50%.
8. Comparison Charts/Tables
| Aspect | Coal | Oil & Natural Gas |
|---|---|---|
| Origin | Gondwana (ancient), Tertiary (younger) | Sedimentary basins |
| Major States | Jharkhand, Odisha, Chhattisgarh | Offshore Maharashtra, AP, Gujarat, Assam |
| Production | High domestic (~80% power) | Low domestic (85% oil, 50% gas import) |
| Use | Power, steel | Transport, fertilizer, power |
| Environmental Impact | High (CO2, pollution) | Moderate (flaring, spills) |
9. Spatial Context
- Coal: Damodar Valley (Jharkhand-WB), Talcher (Odisha), Korba (Chhattisgarh), Singareni (Telangana).
- Oil: Mumbai High (offshore Maharashtra), KG Basin (AP offshore), Cambay (Gujarat), Assam (Digboi).
- Gas: KG-D6 (AP offshore), Tripura, Cauvery basin (TN).
- Salem/TN relevance: Neyveli lignite (nearby Cuddalore); Cauvery basin gas; Salem district uses coal/lignite power, TN has minor oil/gas potential. Image credit: Wikimedia Commons (CC-BY-SA 4.0) via search, showing map of coal fields and basins in India with major locations labeled. Image credit: Wikimedia Commons (Public Domain) via search, showing map of oil and gas basins in India including Mumbai High and KG basin.
10. Flowchart Summary Geological Formation ? Gondwana Coal (Damodar, Talcher) ? Tertiary Lignite (Neyveli) ? Sedimentary Basins ? Oil & Gas (Mumbai High, KG, Cambay) ? Production & Use (power, transport). Image credit: Wikimedia Commons (CC-BY-SA 4.0) via search, showing simplified flowchart of conventional energy resource distribution in India.
11. Ultra-Short Exam Capsule
- Gondwana Coal: Jharkhand, Odisha, Chhattisgarh.
- Tertiary Coal: Neyveli (TN), Gujarat.
- Mumbai High: Offshore oil.
- KG Basin: Major gas field.
- Coal: ~80% power.
- Oil import: ~85%.
- Gas import: ~50%.
TYPE 2: QUICK REVISION & EXAM TRICKS
1. Highlights & Tricky Points
- Key: Gondwana coal high-grade; Tertiary lignite low-grade.
- Trap: "Coal in Himalayas?" ā No; all Peninsular.
- Trap: "Mumbai High gas?" ā Oil + gas; KG-D6 major gas.
- Trap: Confuse Neyveli (lignite) with major coal (Gondwana).
2. Memory Aids/Mnemonics
- Coal basins: "Damodar Talcher Korba" ? "DTK" (Damodar Talcher Korba).
- Oil-Gas: "Mumbai KG Cambay Assam" ? "MKCA".
- Production: "Coal 80 Power, Oil 85 Import, Gas 50 Import" ? "80-85-50".
3. Confusing Concepts
- Gondwana vs Tertiary Coal: Gondwana = high-grade bituminous (Jharkhand); Tertiary = lignite (TN, Gujarat).
- Gondwana: steel/power; Tertiary: power.
- Oil vs Gas Basins: Mumbai High = oil dominant; KG = gas dominant.
- Both offshore major.
TYPE 3: PYQs & EXPECTED QUESTIONS
1. PYQ Vault
- UPSC Prelims 2013: The largest coal producing state is? ? Jharkhand.
- SSC CGL 2016: Mumbai High is famous for? ? Offshore oil.
- UPSC Prelims 2018: Neyveli lignite mines are in? ? Tamil Nadu.
- RRB NTPC 2019: KG Basin is known for? ? Natural gas.
- SSC CGL 2021: Gondwana coal is found in? ? Peninsular India.
- State PSC (TNPSC 2020): Neyveli is famous for? ? Lignite coal.
- SSC CGL 2019: Bombay High oil field is? ? Offshore Maharashtra.
- RRB JE 2022: Coal nationalization year? ? 1973.
- BPSC 2021: Digboi is famous for? ? Oil (Assam).
- TNPSC 2022: Cauvery basin has? ? Oil and gas potential.
2. 2026 Expected Questions
- Name the major Gondwana coal fields in India.
- Describe the location and importance of Mumbai High oil field.
- What is the significance of the Krishna-Godavari (KG) basin?
- Differentiate between Gondwana and Tertiary coal in India.
- Which state leads in lignite production?
- How do conventional energy resources link to India's import dependence in 2026?