(a) Give the modern classification of mineral deposits and explain in brief the residual and mechanical concentration deposits with suitable examples. (20 marks)

(b) Stating the premise of National Mineral Policy, give the outline of strategic, crit

Question

(a) Give the modern classification of mineral deposits and explain in brief the residual and mechanical concentration deposits with suitable examples. (20 marks)

(b) Stating the premise of National Mineral Policy, give the outline of strategic, critical and essential minerals citing Indian examples. (20 marks)

(c) Give the mode of occurrence, distribution and uses of manganese deposits of India. (10 marks)

UPSC Answer Check · Accepted Answer

The directive 'explain' demands clear exposition with cause-effect reasoning across all three parts. Allocate approximately 40% of time/words to part (a) given its 20 marks, 35% to part (b), and 25% to part (c). Structure as: brief introduction on mineral resource significance → systematic treatment of (a) with genetic classification → (b) with policy framework and mineral categories → (c) with manganese specifics → concluding synthesis on India's mineral security.
- Part (a): Modern genetic classification of mineral deposits (magmatic, hydrothermal, sedimentary, metamorphic, residual, mechanical) with clear hierarchical structure
- Part (a): Residual concentration deposits: lateritic nickel (Sukinda), bauxite (Panchpatmali), iron ore (Singhbhum); explanation of tropical weathering, iron/alumina enrichment, silica removal
- Part (a): Mechanical concentration deposits: placer gold (Kolar paleoplacers), beach placers (monazite in Kerala-Tamil Nadu coast), cassiterite; explanation of density-based sorting in fluvial/marine environments
- Part (b): Premise of National Mineral Policy 2019: security of supply, sustainable mining, private sector participation, scientific exploration, minimal environmental impact
- Part (b): Strategic minerals (rare earth elements, lithium, cobalt—Chhattisgarh REE belts); Critical minerals (copper, tungsten, molybdenum—Malanjkhand, Degana); Essential minerals (iron, manganese, bauxite, coal—Odisha, Jharkhand belts)
- Part (c): Mode of occurrence: bedded/stratiform deposits in Dharwar Supergroup, associated with iron formations; syngenetic-sedimentary origin with later supergene enrichment
- Part (c): Distribution: Balaghat (Madhya Pradesh)—largest producer, high-grade ore; Nagpur-Bhandara (Maharashtra); Keonjhar, Sundergarh (Odisha); Dharwar (Karnataka); Vizianagaram (Andhra Pradesh)
- Part (c): Uses: ferromanganese in steelmaking (deoxidizer, sulfur control), dry cell batteries, chemical industry, aluminum alloying; India's 7th largest global reserves but import dependence for battery-grade manganese

Dimension	Weight	Max marks	Excellent	Average	Poor
Concept correctness	25%	12.5	Demonstrates precise genetic classification in (a) distinguishing residual vs. mechanical processes with correct geochemical/physical mechanisms; accurately defines strategic/critical/essential categories in (b) per NMP 2019 and critical minerals list; correctly identifies manganese mineralogy (pyrolusite, psilomelane) and syngenetic origin in (c)	Basic classification correct but confuses residual with mechanical processes or omits supergene enrichment; generic policy description without specific mineral categorization; manganese occurrence described but origin unclear	Outdated Lindgren or Bateman classifications without genetic basis; conflates all concentration types; fails to distinguish mineral categories or describes manganese only as 'found in rocks'
Diagram / cross-section	15%	7.5	Includes schematic cross-section of laterite profile for residual deposits (A-B-C horizon with duricrust) and fluvial placer channel for mechanical deposits; India's manganese belt map with major mines marked; NMP implementation flowchart	Simple block diagram of laterite or placer without process arrows; rough sketch of manganese distribution; no policy diagram	No diagrams despite clear visual potential; or irrelevant diagrams copied from memory without question linkage
Field evidence	15%	7.5	Cites specific deposits: Sukinda lateritic chromite over peridotite, Ratnagiri bauxite; Kolar gold field paleoplacers, Manavalakurichi beach placers; Balaghat's 40m+ thick ore zones, MOIL operations; references GSI or AMD exploration data	Mentions generic 'eastern ghats' or 'central India' without specific mine names; states 'beach sands of Kerala' without mineral specifics; Balaghat mentioned without grade/reserve data	No named Indian deposits; foreign examples only (Guinea bauxite, Witwatersrand gold); or fictional locations
Quantitative reasoning	15%	7.5	Provides reserve figures: India 142 MT manganese reserves (5% global), Balaghat 40% national production; bauxite 3.9 BT reserves; REE 6.9 MT; policy targets like 33% exploration area auctioned; grade distinctions (46%+ Mn for battery grade vs. 35% for ferromanganese)	Round figures like 'India has large reserves' or 'major producer'; mentions MOIL production without tonnage; vague 'high grade' without percentage	No quantitative data; incorrect orders of magnitude; confuses reserve with resource figures
Indian / economic relevance	30%	15	Links NMP 2019 to Atmanirbhar Bharat, Make in India; explains import vulnerability for critical minerals (100% lithium, cobalt); manganese's role in steel sector (2nd largest producer target 300MT by 2030); environmental-social governance in tribal mining areas; India's NET ZERO implications for mineral demand	Mentions policy exists without contemporary relevance; states manganese is 'important for steel' without sectoral linkage; generic 'minerals are important for economy'	No policy context; treats question as purely academic mineralogy without economic-geography integration; outdated 1993 or 2008 NMP references without 2019 update

Q6

Directive word: Explain

How this answer will be evaluated

Approach

Key points expected

Evaluation rubric

Practice this exact question

More from Geology 2021 Paper II