Geology 2024 Paper I 50 marks 150 words Compulsory Discuss

Q1

Answer the following questions in about 150 words each: (a) Discuss two widely accepted theories of origin of the earth. Elucidate the position of all planets within the solar system and write the important facts of the earth. (10 marks) (b) What are the planar and linear structures of a rock? Discuss the genesis of boudins. (10 marks) (c) Discuss the applications of remote sensing in Geology. (10 marks) (d) Discuss the process of soil formation. (10 marks) (e) Define dip of a rock bed. What is true dip and apparent dip? Find the strike direction of a bed which dips 30° towards North 30° East. (10 marks)

हिंदी में प्रश्न पढ़ें

निम्नलिखित प्रत्येक प्रश्न का लगभग 150 शब्दों में उत्तर दीजिए : (a) पृथ्वी की उत्पत्ति के संबंध में व्यापक रूप से स्वीकार्य दो सिद्धांतों का वर्णन कीजिए। सभी ग्रहों की सौरमंडल में अवस्थिति दर्शाते हुए पृथ्वी के प्रमुख तथ्यों को लिखिए। (10 अंक) (b) शैल की तलीय एवं रेखीय संरचनाएं क्या हैं? बाउडिन के उद्भव का वर्णन कीजिए। (10 अंक) (c) भूगर्भ-विज्ञान में सुदूर संवेदन के अनुप्रयोगों का वर्णन कीजिए। (10 अंक) (d) मृदा निर्माण की प्रक्रिया का वर्णन कीजिए। (10 अंक) (e) शैलतल की नति को परिभाषित कीजिए। वास्तविक नति एवं आभासी नति क्या है? एक तल जिसकी नति 30°; उत्तर 30° पूर्व को है, के नतिलम्ब की दिशा ज्ञात कीजिए। (10 अंक)

Directive word: Discuss

This question asks you to discuss. The directive word signals the depth of analysis expected, the structure of your answer, and the weight of evidence you must bring.

See our UPSC directive words guide for a full breakdown of how to respond to each command word.

How this answer will be evaluated

Approach

The directive 'discuss' demands a balanced, analytical treatment across all five sub-parts with ~30 words each. For (a), briefly contrast Nebular Hypothesis and Big Bang Theory, list planets in order, and note Earth's unique features. For (b), define planar/linear structures with examples, then explain boudinage formation. For (c), enumerate remote sensing applications in mineral exploration, groundwater, and disaster management. For (d), outline soil formation through weathering, horizon development, and factors. For (e), define dip concepts clearly, then solve the strike calculation showing perpendicular relationship to dip direction. Allocate ~20% time to (e) due to calculation requirement.

Key points expected

  • (a) Two origin theories: Nebular Hypothesis (Laplace) and Big Bang Theory; planetary sequence from Sun; Earth's density, atmosphere, hydrosphere, and magnetic field uniqueness
  • (b) Planar structures: bedding, foliation, cleavage, joints, faults; Linear structures: lineation, fold axes, mineral streaks; Boudin genesis: ductile extension of competent layer in incompetent matrix
  • (c) Remote sensing applications: lithological mapping, structural analysis, mineral exploration (GSI projects), groundwater prospecting, landslide monitoring, coastal zone management
  • (d) Soil formation: mechanical/chemical weathering, humus accumulation, horizon differentiation (O-A-B-C-R), factors (climate, parent rock, topography, time, organisms)
  • (e) Dip definition: maximum inclination angle; True dip vs apparent dip; Strike calculation: perpendicular to dip direction, hence strike is N60°W-S60°E or 120°-300°

Evaluation rubric

DimensionWeightMax marksExcellentAveragePoor
Concept correctness25%12.5Accurately describes both origin theories with key proponents; correctly classifies all planetary positions; precisely defines planar/linear structures with genetic distinctions; correctly solves strike as perpendicular to dip direction (N60°W-S60°E)Identifies theories and planets with minor errors; basic definitions of structures; attempts strike calculation but with directional confusionConfuses theories (e.g., Steady State with Big Bang); incorrect planetary order; conflates planar and linear structures; completely wrong strike calculation
Diagram / cross-section15%7.5Sketches boudin geometry showing competent layer necking; draws clear dip-strike relationship diagram with proper angular notation; solar system schematic with orbital planesSimple boudin sketch without genetic context; basic dip-strike diagram missing angle labels; minimal planetary arrangementNo diagrams despite clear visual requirements; or completely incorrect diagrams (e.g., strike parallel to dip)
Field evidence15%7.5Cites specific Indian examples: boudins from Singhbhum shear zone; remote sensing in Aravalli gold exploration; laterite soil profiles of Western Ghats; GSI's Bhukosh portal applicationsGeneric field references without Indian specificity; mentions soil horizons without location contextNo field examples; purely theoretical treatment across all sub-parts
Quantitative reasoning20%10Correctly calculates strike direction: dip is 30° towards N30°E, so strike is N60°W-S60°E (or 120°-300°); shows perpendicular relationship mathematically; notes apparent dip formula tan(apparent) = tan(true) × cos(angle between sections)Correct final strike answer but without derivation; mentions apparent dip concept without formulaIncorrect strike calculation (e.g., states strike as N30°E); no quantitative treatment; confuses dip and strike angles
Indian / economic relevance25%12.5Links remote sensing to India's National Mineral Policy and GSI's FSI projects; connects soil formation to Indian agriculture (black cotton soils, alluvial plains); notes economic significance of boudin-hosted mineralization; mentions ISRO's Bhuvan/Resourcesat applicationsBrief mention of Indian remote sensing programs without economic linkage; generic soil importance statementNo Indian context; misses economic implications entirely; Western-centric examples only

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