UPSC 2020 Geology Optional Question Paper, held in January 2021. Download paper here. Subject wise question have been provided.
General Geology
- Discuss the different types of meteorites. (5)
- Explain the internal structure of the earth. Add a note on discontinuities with neat sketches. (20)
- Explain the magnitude and intensity as an expression of the size of an earthquake. Add a note on the damage caused by an earthquake. (15)
- Discuss the mechanism of seafloor spreading and give four evidences indicateing the expansion in oceanic crust. (15)
Geomorphology
- Briefly describe two diagnostic landforms each of hot-arid and cold-arid climate. (5)
- Discuss the different in geomorphology of the Eastern Coast and Western Coast of India. What is the main reason of the difference? (15)
- Describe three main controlling factors of soil formation. How does the modern soil differ from the palaeosoil? (15)
Remote Sensing
- Discuss various fields in which IRS data can be used for the development work and management of resources. (5)
- Discuss the salient features of Indian satellites Cartosat-3 and RISAT-2B. How are these superior to their predecessors? (20)
Structural Geology
- How do we determine the top of beds from primary features? (5)
- Briefly describe the classification of fold on the basis of fold attitude (dip and plunge) (5)
- What is an unconformity and what are its structural and stratigraphic importance? Discuss four different types of unconformities with neat sketches. (15)
- What is shear zone and what are the conditions of its formation? Discuss its general characteristics and types based on deformation type. (15)
- Discuss Mohr’s stress diagram and its significance. What is its relevance in interpreting different stress conditions in rocks? (20)
Paleontology
- Describe three processes by which plant remains and invertebrate shells can be preserved as fossils. (5)
- Discuss the morphological trends in the evolution of Homo sapiens from Proto-hominins. (20)
- Give an account of the Lower Gondwana flora from peninsular and extra-peninsular India. What environment conditions do they indicate? (15)
- Name two microfossils and discuss how these are used in reconstructing the palaeoclimatic conditions. (15)
Stratigraphy / Indian Stratigraphy
- Give an account of the mineral wealth associated with the Cuddapah Supergroup of rocks. (5)
- Briefly describe the economic mineral deposits associated with the Tertiary rocks of India. (5)
- Draw the tectonic sub division map of India and discuss the salient features of each sub-division. (15)
- Describe the standard stratigraphic time scale of the earth, beginning from the oldest to youngest. Discuss the principal events that took place during the time units. (20)
- Discuss about the Cretaceous- Tertiary boundary (K-T boundary) with examples from India. (15)
Hydrogeology and Engineering Geology
- Explain the factors influencing the groundwater movement and storage. (5)
- Discuss five engineering properties of rocks. (5)
- Explain the process of salt water intrusion with neat sketches. Give examples form India. (15)
- What is landslide? Explain the different types and their causes. Give two examples from India. (15)
- Explain the natural and artificial recharge processes to enhance the ground water potential in hard and soft rock terrains. (20)
Mineralogy
- How do you measure refractive index of minerals and distinguish high and low relief minerals under microscope? (10)
- Write about the symmetry elements of a crystal. (10)
- Briefly write about the crystal forms of hexagonal system using projection diagrams.
- Define pleochroism of minerals and write about the utility of pleochroism to distinguish minerals and provide examples.
Igneous and Metamorphic Petrology
- Explain the salient features exhibited by rocks due to thermal metamorphism. (10)
- Explain with suitable examples the implications of albite-anorthite solid solutions in the understanding of crystallisation of magma. (10)
- What do you understand by the term texture of a rock? How do you relate the textures of igneous rocks with the process of magmatic crystallisation? (20)
- Critically discuss the petrogenesis of anorthosites. Comment on the tectonic significance on the distribution of anorthosites. (20)
- Explain the effects of prograde metamorphism on impure carbonate rocks. (10)
Sedimentary Petrology
- How are sedimentary rocks classified in general based on their process of formation. (10)
- Illustrate with neat sketches the sedimentary facies and facies associations that are likely to develop in a progradational deltaic environment. (20)
- ‘Classification of carbonate rocks based on textural components may be useful for interpretation of depositional environment’. Justify the statement with reason. (20)
- How would you distinguish burial diagenetic cements in carbonate rocks from petrographic studies? Draw neat sketches in support of your answer. (10)
Economic Geology
- Explain the processes of formation of syngenetic and epigenetic ore deposits with suitable examples. (10)
- Describe the geology of the East Coast Bauxite deposits of India. (10)
- Discuss the salient features of various types of lead-zinc ore deposits. Illustrate your answer with schematic diagrams to explain the process of ore formation. (20)
- Describe the geological characteristic of important chromite deposits from different parts of the Indian shield. (20)
- What is coal bed methane? How is it exploited? (10)
Mining Geology
- Discuss various methods of conservation of minerals resources for achieving sustainable mineral development (10)
- What are the factors which influence the mobility of elements in near surface environment? How does understanding the mobility of elements help in choosing indicators elements for a geochemical exploration programme? (20)
- A vein type copper ore body trending E-W with 90o dip and having strike length of 150 m is exposed on the surface. Four trenches are made across the ore body at constant interval, including one trench each at E and W end of the ore body. Thickness of the ore body and assay value measured from the trenches are given in the table.
Assuming that the ore body extends up to a depth of 50 m, and the specific gravity of the ore is 2.8, calculate the tonnage, grade and total copper content of the ore body. (20)
| Trench number (E to W) | Thickness of ore body (m) | Assay (wt.% Cu) |
| 1 | 2.5 | 1.2 |
| 2 | 2.1 | 1.6 |
| 3 | 1.6 | 2.0 |
| 4 | 1.8 | 1.5 |
4. Explain the seismic methods of mineral prospecting. (10)
Geochemistry and Environmental Geology
- Illustrate with examples the role of chemical bonding in minerals in determining certain properties. (10)
- Write about the causes of Sea level changes. (10)
- What do you mean by ‘primitive mantle’? Illustrate the Cosmo chemical and observational constraints on mantle composition. (20)
- Explain about the impact of volcanic eruptions on the environment. (20)
- Briefly mention measures to mitigate lanslides. (10)





