Geology

UPSC Geology 2023 — Paper I

All 8 questions from UPSC Civil Services Mains Geology 2023 Paper I (400 marks total). Every stem reproduced in full, with directive-word analysis, marks, word limits, and answer-approach pointers.

8Questions
400Total marks
2023Year
Paper IPaper

Topics covered

Tectonic features, weathering, remote sensing, rock types, folds (1)Radiometric dating, electromagnetic radiation, joints classification (1)Glaciers, meteorites, rock cleavage (1)Shear zones, coastal classification, volcanoes (1)Siwalik fauna, fossils, Krol Formation, hydrogeology, engineering properties (1)Equidae evolution, Precambrian-Cambrian boundary, rainwater harvesting (1)Dharwar Supergroup, microfossils, earthquake resistant structures (1)Groundwater quality, ocean palaeobathymetry, Tethyan sequence (1)

A

Q1
50M 150w Compulsory describe Tectonic features, weathering, remote sensing, rock types, folds

Answer the following questions in about 150 words each: (a) Describe the tectonic features and evolution of the 'continental crust'. (10 marks) (b) Describe the physical and chemical weathering processes. (10 marks) (c) Describe the Spatial and Spectral resolution of a remote sensor with examples. (10 marks) (d) Briefly describe the Cataclasite and Pseudotachylite rocks. (10 marks) (e) Discuss the differences between Symmetrical and Asymmetrical folds with the help of neat diagrams. (10 marks)

हिंदी में पढ़ें

निम्नलिखित प्रश्नों में से प्रत्येक का लगभग 150 शब्दों में उत्तर दीजिए : (a) महाद्वीपीय पटल के विवर्तनिक लक्षणों एवं विकास का वर्णन कीजिए । (10 अंक) (b) भौतिक एवं रासायनिक अपक्षय प्रक्रियाओं का वर्णन कीजिए । (10 अंक) (c) सुदूर संवेदी के आकाशीय एवं स्पेक्ट्रमी विभेदन का उदाहरणों सहित वर्णन कीजिए । (10 अंक) (d) उपदलाश्म (कैटाक्लेसाइट) एवं स्यूडोटाचाइलाइट शैलों का संक्षिप्त में वर्णन कीजिए । (10 अंक) (e) स्वच्छ आरेखों की सहायता से सममित एवं असममित वलनों की चर्चा कीजिए । (10 अंक)

Answer approach & key points

Framework: Geology Paper 1: Define > Process > Field/Petrographic Evidence > Indian Example. (a) describe: define > structure or process in order > labelled diagram > significance | (b) describe: define > structure or process in order > labelled diagram > significance | (c) describe: define > structure or process in order > labelled diagram > significance | (d) describe: define > structure or process in order > labelled diagram > significance | (e) discuss: intro > 3-4 dimensions > example > balanced close Full marks: All parts: precise definitions, clear processes, Indian examples, neat diagrams, and economic/stratigraphic links.

  • Define continental crust (granitic, 30-70km thick)
  • Describe tectonic features (cratons, orogens, rifts)
  • Explain evolution (accretion, subduction, isostasy)
  • Provide Indian example (Deccan, Himalaya, or Craton)
  • Define physical weathering (mechanical breakdown)
  • Define chemical weathering (mineral alteration)
  • List key processes (e.g., hydration, oxidation)
  • Provide Indian example (e.g., laterite formation)
Q2
50M describe Radiometric dating, electromagnetic radiation, joints classification

(a) Describe the types of radiometric dating techniques used to establish the age of the Earth. (20 marks) (b) Discuss the different types of interaction of electromagnetic radiation with the atmosphere of the earth and its impact on remote sensing images. (15 marks) (c) What are joints ? Describe the Geometric and Genetic classification of joints with neat diagrams. (15 marks)

हिंदी में पढ़ें

(a) पृथ्वी की आयु स्थापित करने के लिए उपयोग की जाने वाली रेडियोमितीय काल-निर्धारण तकनीकों के प्रकारों का वर्णन कीजिए । (20 अंक) (b) पृथ्वी के वातावरण के साथ विद्युत चुंबकीय विकिरण की विभिन्न प्रकार की पारस्परिक क्रियाओं एवं सुदूर संवेदी प्रतिबिंबों पर इसके प्रभाव की विवेचना कीजिए । (15 अंक) (c) संधि क्या है ? स्वच्छ आरेखों की सहायता से संधियों के ज्यामितीय एवं आनुवंशिक वर्गीकरण का वर्णन कीजिए । (15 अंक)

Answer approach & key points

(a) describe: define > structure or process in order > labelled diagram > significance | (b) discuss: intro > 3-4 dimensions > example > balanced close | (c) describe: define > structure or process in order > labelled diagram > significance Full marks: Comprehensive, accurate, and well-structured answers with specific examples and diagrams.

  • Definition of radiometric dating and half-life
  • U-Pb dating of zircon (oldest minerals)
  • Rb-Sr dating of meteorites (oldest solar system material)
  • Mention of the 4.54 billion year age
  • Definition of electromagnetic radiation (EMR)
  • Explanation of scattering (Rayleigh/Mie)
  • Explanation of absorption (by H2O, CO2, O3)
  • Identification of atmospheric windows
Q3
50M elucidate Glaciers, meteorites, rock cleavage

(a) Elucidate the types of glacier and illustrate the erosional and depositional features produced by the valley-glaciers. (20 marks) (b) Discuss the origin, composition and classification of meteorites. (15 marks) (c) What is a rock cleavage ? Describe the different types of rock cleavages with the help of neat diagrams. (15 marks)

हिंदी में पढ़ें

(a) हिमनद के प्रकारों पर प्रकाश डालिए तथा घाटी-हिमनद द्वारा निर्मित अपरदन एवं निक्षेपण लक्षणों को उदाहरण दे कर समझाइए । (20 अंक) (b) उल्कापिंडों की उत्पत्ति, संरचना और वर्गीकरण की विवेचना कीजिए । (15 अंक) (c) शैल विदलन क्या है ? स्पष्ट आरेखों की सहायता से विभिन्न प्रकार के शैल विदलनों का वर्णन कीजिए । (15 अंक)

Answer approach & key points

Framework: Geology, Paper 1. (a) explain: definition/context > points in order > small example > short close | (b) discuss: intro > 3-4 dimensions > example > balanced close | (c) describe: define > structure or process in order > labelled diagram > significance Full marks: Precise definitions, detailed mechanisms, named Indian examples, and clear diagrams.

  • Types of glaciers (e.g., Alpine, Continental, Piedmont)
  • Erosional features: U-shaped valley, Cirque, Arête, Horn
  • Depositional features: Moraines, Drumlins, Erratics
  • Neat diagrams illustrating erosional/depositional landforms
  • Origin: Solar system formation, parent bodies
  • Composition: Stony, Iron, Stony-iron
  • Classification: Chondrites, Achondrites, Meteorites
  • Balanced close on significance
Q4
50M describe Shear zones, coastal classification, volcanoes

(a) What is a Shear Zone ? Describe the different Shear Sense indicators. (20 marks) (b) Enumerate the Shepard's classification of coast's and briefly describe the marine cycle of erosion along a shoreline of submergence. (15 marks) (c) Describe the different types of volcanoes based on mode of the eruption and its associated products. Add a note on positive and negative relief features associated with volcanoes. (15 marks)

हिंदी में पढ़ें

(a) अपरूपण क्षेत्र क्या है ? विभिन्न प्रकार के अपरूपण अभिदिशा सूचकों का वर्णन कीजिए । (20 अंक) (b) तटों का 'शेपर्ड' वर्गीकरण लिखें और तटरेखा के निमज्जन के साथ सागरीय चक्र के अपरदन का संक्षिप्त वर्णन कीजिए । (15 अंक) (c) उद्गार की विधि और उससे सम्बन्धित उत्पादों के आधार पर विभिन्न प्रकार के ज्वालामुखियों का वर्णन करें । ज्वालामुखियों से सम्बन्धित सकारात्मक एवं नकारात्मक उच्चावच (रिलीफ) विशेषताओं पर टिप्पणी कीजिए । (15 अंक)

Answer approach & key points

Framework: Geology, Paper 1. (a) describe: define > structure or process in order > labelled diagram > significance | (b) enumerate: list the items in order > one line each > no commentary | (c) describe: define > structure or process in order > labelled diagram > significance Full marks: Precise definitions, labeled diagrams, specific Indian examples, clear causal chains.

  • Definition of shear zone as a ductile deformation structure
  • Description of asymmetric indicators (S-C fabric, sigma clasts)
  • Description of symmetric indicators (porphyroclasts, boudins)
  • Labeled sketches of at least two indicators
  • List of Shepard's classification (emergent, submergent, etc.)
  • Description of marine cycle of erosion stages
  • Specific features of submergent shoreline (drowned valleys)
  • Mention of rias or fjords as examples

B

Q5
50M 150w Compulsory enumerate Siwalik fauna, fossils, Krol Formation, hydrogeology, engineering properties

Answer the following questions in about 150 words each: (a) Enumerate the different types of siwalik fauna and discuss their palaeoecology. (10 marks) (b) Define fossil and give examples of two index fossils each from Palaeozoic, Mesozoic and Cenozoic Era and indicate the age of those index fossils. (10 marks) (c) Describe the lithology, palaeoenvironment and age of Krol Formation. (10 marks) (d) Briefly discuss the water-bearing properties of rocks. (10 marks) (e) What are the engineering properties of rocks that make them suitable for use as building materials? (10 marks)

हिंदी में पढ़ें

निम्नलिखित प्रश्नों में से प्रत्येक का लगभग 150 शब्दों में उत्तर दीजिए । (a) विभिन्न प्रकार के शिवालिक प्राणिजात के बारे में बतायें और उनकी पुरापारिस्थितिकी की विवेचना कीजिए । (10 अंक) (b) जीवाश्म को परिभाषित कीजिए और प्रत्येक पुराजीवी, मध्यजीवी एवं नूतनजीवी महाकल्पों के दो सूचक जीवाश्मों के उदाहरण दीजिए एवं उन सूचक जीवाश्मों की आयु बताइए । (10 अंक) (c) क्रोल शैल समूह के शैल लक्षण, पुरा वातावरण एवं आयु का वर्णन कीजिए । (10 अंक) (d) शैलों के जलधारी गुणों का संक्षिप्त में वर्णन कीजिए । (10 अंक) (e) शैलों के अभियांत्रिक गुण क्या हैं जो उन्हें निर्माण सामग्री के रूप में उपयोग के लिए उपयुक्त बनाते हैं ? (10 अंक)

Answer approach & key points

Framework: Geology Paper 1: Define > Process > Field/Petrographic Evidence > Indian Example. (a) enumerate: list the items in order > one line each > no commentary | (b) define: precise definition > the distinguishing feature > one example | (c) describe: define > structure or process in order > labelled diagram > significance | (d) discuss: intro > 3-4 dimensions > example > balanced close | (e) explain: definition/context > points in order > small example > short close Full marks: Precise definitions, specific Indian examples, clear stratigraphic context, and accurate technical terminology.

  • List distinct Siwalik fauna types (e.g., mammals, birds)
  • Discuss palaeoecology of each type
  • Link fauna to specific Siwalik formations (e.g., Baragwanth)
  • Mention stratigraphic age (Miocene-Pliocene)
  • Precise definition of fossil
  • Two index fossils for Palaeozoic Era
  • Two index fossils for Mesozoic Era
  • Two index fossils for Cenozoic Era
Q6
50M elucidate Equidae evolution, Precambrian-Cambrian boundary, rainwater harvesting

(a) Elucidate an evolutionary trend of Equidae with Indian occurrence. (20 marks) (b) Discuss the pre-cambrian/cambrian boundary with Indian examples. (15 marks) (c) What is "Rainwater harvesting"? Describe its technique with neat sketches. (15 marks)

हिंदी में पढ़ें

(a) भारतीय उपलब्धता के साथ एक्विडी की विकासवादी प्रवृति पर प्रकाश डालिए । (20 अंक) (b) भारतीय उदाहरणों के साथ प्रीकैम्ब्रियन/कैम्ब्रियन सीमा की विवेचना कीजिए । (15 अंक) (c) "वर्षाजल छाजन क्या है" ? स्वच्छ आरेखों के साथ इसकी तकनीकी का वर्णन कीजिए । (15 अंक)

Answer approach & key points

Framework: Geology Paper 1: Define > Process > Field/Petrographic Evidence > Indian Example. (a) explain: definition/context > points in order > small example > short close | (b) discuss: intro > 3-4 dimensions > example > balanced close | (c) describe: define > structure or process in order > labelled diagram > significance Full marks: Comprehensive, specific, and well-structured with all required elements and Indian examples.

  • Define Equidae and evolutionary trend
  • Describe morphological changes (e.g., limb, teeth)
  • Name specific Indian Equidae species
  • State stratigraphic age of Indian occurrence
  • Define Pre-Cambrian/Cambrian boundary
  • Describe key geological changes at boundary
  • Name specific Indian examples of boundary
  • State stratigraphic age of Indian examples
Q7
50M describe Dharwar Supergroup, microfossils, earthquake resistant structures

(a) Describe the stratigraphic sequence of Dharwar Supergroup and add a note on its economic importance. (20 marks) (b) Elucidate the different types of microfossils and add a note on their composition and applications. (15 marks) (c) How does an Earthquake occur? Describe the construction patterns of earthquake resistant structures. (15 marks)

हिंदी में पढ़ें

(a) धारवाड़ महासंघ की स्तरिक अनुक्रम का वर्णन कीजिए और इसके आर्थिक महत्व पर एक टिप्पणी जोड़िए । (20 अंक) (b) विभिन्न प्रकार के सूक्ष्म जीवाश्मों का विवरण दीजिए और उनके संघटन एवं अनुप्रयोगों के बारे में एक टिप्पणी जोड़िए । (15 अंक) (c) एक भूकंप कैसे आता है ? भूकंपरोधी संरचना के रचना प्रतिरूप का वर्णन कीजिए । (15 अंक)

Answer approach & key points

(a) describe: define > structure or process in order > labelled diagram > significance | (b) explain: definition/context > points in order > small example > short close | (c) explain: definition/context > points in order > small example > short close Full marks: Comprehensive, specific, and well-structured answers with diagrams and Indian examples.

  • Define Dharwar Supergroup and its age (Archean/Proterozoic).
  • List formations in order (e.g., Bhima, Kolar, Chitrapur).
  • Describe lithology of each formation (e.g., BIF, schists).
  • Note economic importance (e.g., iron, gold, manganese).
  • Define microfossils and their size range.
  • List different types (e.g., foraminifera, diatoms, radiolarians).
  • Describe composition (e.g., calcite, silica, chitin).
  • Note applications (e.g., biostratigraphy, paleo-environment).
Q8
50M discuss Groundwater quality, ocean palaeobathymetry, Tethyan sequence

(a) Discuss briefly how do chemical, physical and bacteriological properties determine the usability of ground-water. (20 marks) (b) Establish the ocean palaeobathymetry using marine fossils with the help of labelled diagram. (15 marks) (c) Discuss the palaeozoic sequence of Kumaun and Garhwal (Tethyan sequence) Himalaya. Add a note on its fossil contents. (15 marks)

हिंदी में पढ़ें

(a) भौम-जल की उपयोगिता को निर्धारित करने वाले रासायनिक भौतिक एवं जीवाण्विक गुणों की संक्षेप में चर्चा कीजिए । (20 अंक) (b) समुद्री जीवाश्मों का उपयोग करते हुए महासागर पुराअनुगभीर को अंकित आरेख की सहायता से स्थापित कीजिए । (15 अंक) (c) कुमाऊं और गढ़वाल (टेथियन अनुक्रम) हिमालय के पुराजीवी अनुक्रम का वर्णन कीजिए । उनके जीवाश्मी अंशों के बारे में एक टिप्पणी जोड़िए । (15 अंक)

Answer approach & key points

Framework: Geology Paper 1: Define > Process > Field/Petrographic Evidence > Indian Example. (a) discuss: intro > 3-4 dimensions > example > balanced close | (b) explain: definition/context > points in order > small example > short close | (c) discuss: intro > 3-4 dimensions > example > balanced close Full marks: Precise, specific, and well-linked to Indian examples with clear diagrams.

  • Chemical: pH, hardness, nitrates, heavy metals
  • Physical: turbidity, TDS, temperature, colour
  • Bacteriological: coliforms, E. coli, pathogens
  • Linkage to drinking/irrigation suitability
  • Concept of depth zonation (bathymetry)
  • Specific index fossils for depth (e.g., foraminifera, corals)
  • Labelled diagram showing depth vs. fossil assemblage
  • Link between fossil type and water depth

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