Consider the following statements: 1. Natural gas occurs in the Gondwana beds. 2. Mica occurs in abundance in Kodarma. 3. Dharwars are famous for petroleum. Which of the statements given above is/are correct?
Contents17
- A1 and 2
- B2 only
- C2 and 3
- DNone
Show answer
Answer: (B) 2 only
Statement 2 is correct —
Kodarma (in Jharkhand) is well known as a major mica-producing region of India.
Statement 1 is wrong —
Natural gas is obtained along with oil in all the oil fields, and exclusive reserves are found along the eastern coast and in states like
- Tamil Nadu
- Odisha
- Andhra Pradesh
- Tripura
- Rajasthan.
It is not specifically associated with Gondwana beds (which are known for coal, not natural gas).
Statement 3 is wrong —
Dharwar rocks are famous for metallic minerals (like iron ore, manganese, copper), not petroleum.
Crude petroleum occurs in sedimentary rocks of the tertiary period, not in Dharwar formations.
So only statement 2 is correct.
Kodarma in Jharkhand is India's leading mica producer, supplying most of the country's mica used in electrical and cosmetic industries.
UPSC is testing whether students can distinguish between rock formations and their associated minerals - Gondwana beds contain coal, Dharwar rocks contain metallic minerals like iron ore, while petroleum comes from sedimentary rocks of tertiary period.
Gondwana Formations & Associated Minerals
Geography Gondwana beds Natural gas
Gondwana Formations: Coal Deposits & Mineral Association
Gondwana beds are famous for coal deposits, not natural gas
Gondwana formations are sedimentary rocks from Permian-Triassic period
Natural gas occurs in oil fields and eastern coastal regions
What are Gondwana Beds
Gondwana formations are sedimentary rock layers formed during the Permian to Triassic period (250-200 million years ago). These beds are primarily known for coal deposits — not oil or natural gas.
Gondwana vs Other Formations
Formation | Age | Primary Minerals | Key States |
|---|---|---|---|
Gondwana | Permian-Triassic | Coal, some iron ore | Jharkhand, Odisha, Chhattisgarh |
Tertiary Sedimentary | Tertiary Period | Petroleum, Natural Gas | Assam, Gujarat, Mumbai High |
Dharwar | Archaean | Iron ore, Gold, Copper | Karnataka, Andhra Pradesh |
Major Gondwana Coalfields
Jharia Coalfield (Jharkhand) — largest coal reserves
Korba Coalfield (Chhattisgarh) — thermal power hub
Talcher Coalfield (Odisha) — open cast mining
Singrauli Coalfield (MP-UP border) — super thermal power
Trap: UPSC tests confusion between Gondwana = Coal vs Tertiary = Oil/Gas
Trap: Don't confuse Gondwana beds with Gondwanaland (ancient supercontinent)
Trap: Natural gas occurs with petroleum, not with coal deposits
Kodarma Mica Belt
Geography Mica Kodarma
Kodarma: India's Mica Capital & Mining Hub
Kodarma (Jharkhand) is India's largest mica-producing region
Mica occurs in pegmatite veins of crystalline rocks
Muscovite and biotite are two main types of mica
Kodarma Mica Belt
Kodarma in Jharkhand is India's premier mica-producing region. The mica deposits occur in pegmatite veins within crystalline rocks of the Chotanagpur Plateau.
Major Mica Producing States
State | Major Districts | Type of Mica | % of Production |
|---|---|---|---|
Jharkhand | Kodarma, Hazaribagh | Muscovite | 60% |
Andhra Pradesh | Nellore, Kurnool | Muscovite | 20% |
Rajasthan | Ajmer, Jaipur | Biotite | 15% |
Bihar | Gaya, Nawada | Muscovite | 5% |
Uses of Mica
Electrical industry — insulation in electrical equipment
Electronics — capacitors and circuit boards
Cosmetics — shimmer and glitter in makeup
Paint industry — decorative and protective coatings
Mica Belt Location
Source: LotusArise — Mica, Limestone distribution in India (Non-Metallic) - UPSC - UPSC ... · lotusarise.com
Dharwar Formations & Metallic Minerals
Geography Dharwars petroleum
Dharwar Formations: Metallic Minerals Hub
Dharwar rocks are famous for metallic minerals, not petroleum
Iron ore, gold, copper, manganese are key Dharwar minerals
Petroleum occurs in tertiary sedimentary rocks, not crystalline rocks
Dharwar System Overview
Dharwar formations are ancient crystalline rocks of the Archaean era. These are part of the Peninsular Shield and are renowned for metallic minerals — particularly iron ore and gold.
Dharwar vs Petroleum-bearing Formations
Rock Type | Age | Key Minerals | Examples |
|---|---|---|---|
Dharwar (Crystalline) | Archaean | Iron ore, Gold, Copper | Ballari, Kolar Gold Fields |
Tertiary Sedimentary | Tertiary Period | Petroleum, Natural Gas | Mumbai High, Digboi |
Gondwana (Sedimentary) | Permian-Triassic | Coal | Jharia, Korba |
Dharwar Mineral Distribution
# Dharwar Formations
## Iron Ore
- Ballari (Karnataka)
- Keonjhar (Odisha)
- Dantewada (Chhattisgarh)
## Gold
- Kolar (Karnataka)
- Hutti (Karnataka)
- Ramagiri (Andhra Pradesh)
## Copper
- Chitradurga (Karnataka)
- Singhbhum (Jharkhand)
- Balaghat (MP)
## Manganese
- Sandur (Karnataka)
- Kalahandi (Odisha)
- Nagpur (Maharashtra)Trap: Statement 3 tries to confuse Dharwar = Metallic with Sedimentary = Petroleum
Trap: Petroleum needs sedimentary environment, not crystalline/metamorphic rocks
Trap: Don't mix up Dharwar (metallic) with Deccan Trap (basaltic)
Natural Gas Distribution in India
Geography Natural gas
Natural Gas Reserves & Distribution in India
Natural gas occurs with petroleum in oil fields
Major reserves: Eastern coast, Gujarat, Rajasthan
KG Basin (Andhra Pradesh) is largest offshore gas field
Natural Gas Occurrence
Natural gas typically occurs alongside crude petroleum in the same sedimentary formations. India also has exclusive natural gas reserves, particularly along the eastern coast and in states like Rajasthan and Tripura.
Major Natural Gas Fields
Field/Basin | State | Type | Key Feature |
|---|---|---|---|
Krishna-Godavari Basin | Andhra Pradesh | Offshore | Largest gas reserves |
Mumbai High | Maharashtra | Offshore | Oil + associated gas |
Hazira-Bijaipur | Gujarat | Onshore | Major gas processing |
Tripura Gas Fields | Tripura | Onshore | Exclusive gas reserves |
Barmer Basin | Rajasthan | Onshore | Recent discoveries |
Gas Field Locations
Source: LotusArise — Natural Gas Reserves in India (with Map) - UPSC - UPSC Notes ... · lotusarise.com
Trap: Natural gas is NOT found in Gondwana beds (coal formations)
Trap: Gas occurs in tertiary sedimentary rocks, same as petroleum
Trap: Associated gas (with oil) vs Non-associated gas (exclusive reserves)