Geology IAS Paper 2 UPSC 2018 with Solutions
In this article, all questions of Geology Optional Paper 2 are answered. Click on the question links to view the answers.
This article is part of Synopsis IAS Geology Optional Course for UPSC IAS.
Geology Optional Paper 2 UPSC 2018 - Question Paper with Solutions
Click on the links for the solutions
SECTION-A
Geology 1a'Five-fold rotational symmetry is not possible in minerals' justify the statement. UPSC 2018, 10 Marks
Geology 1b Explain the symmetry elements in a stereogram of general form {hkil} in the hexagonal-scalenohedral class. UPSC 2018, 10 Marks
Geology 1c Explain the role of decompression in magma generation. UPSC 2018, 10 Marks
Geology 1d Illustrate with neat sketches the formation of porphyritic and ophitic textures in gabbroic rocks using suitable binary phase diagram of pyroxene and plagioclase feldspar. UPSC 2018, 10 Marks
Geology 1e What are sparry allochemical carbonate rocks? Comment on their depositional environment. UPSC 2018, 10 Marks
Geology 2a Illustrate with neat sketches internal structure of pyroxene group of minerals. Give a generalized classification of pyroxene group based on composition. UPSC 2018, 20 Marks
Geology 2b Illustrate with neat sketches internal structure of calcite. How would you explain the differences in the internal structure of calcite and its polymorph aragonite? UPSC 2018, 20 Marks
Geology 2c Explain with the help of indicatrix diagram how the birefringence of a uniaxial mineral depends on crystallographic orientation of the mineral thin-section when studied under petrological microscope. UPSC 2018, 10 Marks
Geology 3a What are continental flood basalts? Illustrate with example from India. Discuss the petrogenesis and tectonic significance of such basalts. UPSC 2018, 20 Marks
Geology 3b Illustrate with appropriate mineral reactions prograde metamorphism of argillaceous sedimentary rocks. UPSC 2018, 20 Marks
Geology 3c What are migmatites? Comment on their origin. UPSC 2018, 10 Marks
Geology 4a Illustrate with neat sketches primary sedimentary structures in sands from bed load transport. How such structures can be used for interpretation of depositional environments? UPSC 2018, 20 Marks
Geology 4b Give a generalized classification of sandstone. State genetic significance of such classification. UPSC 2018, 20 Marks
Geology 4c Why are 'fining upward' facies sequences considered as one of the most important criteria for recognizing deposits of meandering fluvial depositional system? UPSC 2018, 10 Marks
SECTION-B
Geology 5a Calculate the wt.% of iron in the following minerals, and arrange these minerals in order of increasing iron content. (Atomic weight of Fe = 56, Cr=52, Ti=48 and O = 16) Ilmenite, magnetite, chromite, hematite. UPSC 2018, 10 Marks
Geology 5b Describe the geology of Neyveli lignite deposit and the unique problem in mining of this deposit. UPSC 2018, 10 Marks
Geology 5c What are the types of samples collected and analysed in geochemical exploration programmes? Which one of these samples is generally preferred and why is it preferred? UPSC 2018, 10 Marks
Geology 5d What are the surface manifestations of mineral deposits useful in mineral prospecting? UPSC 2018, 10 Marks
Geology 5e Explain the mineralogical phase changes in the mantle of Earth with depth. UPSC 2018, 10 Marks
Geology 6a Explain the hydrothermal process of ore formation. Draw neat sketches illustrating important types of hydrothermal deposits formed in sea floor. UPSC 2018, 20 Marks
Geology 6b Describe the geological characteristics of well-known copper deposits from different cratons of the Indian shield. UPSC 2018, 20 Marks
Geology 6c Some ore deposit types have formed during specific geological periods. Explain with suitable examples the causes for time-bound nature of these deposits. UPSC 2018, 10 Marks
Geology 7a What is path-finder element in geochemical exploration? Explain the selection of path-finder elements and their application with suitable examples. UPSC 2018, 20 Marks
Geology 7b Explain the process of mineral beneficiation by froth flotation and its application for sulphide ores. UPSC 2018, 20 Marks
Geology 7c Five trenches are made at 20 m interval perpendicular to the strike direction of an 80 m long NE-SW trending molybdenite mineralised vein. The width of vein (in m) and assay value of Mo (in wt.%) in each trench (from NE to SW) are listed below: UPSC 2018, 10 Marks
| (Trench) | (Width) | (Assay) |
|---|---|---|
| 1 | 0-6 | 0-20 |
| 2 | 1-8 | 0-35 |
| 3 | 2-4 | 0-14 |
| 4 | 1-5 | 0-18 |
| 5 | 0-4 | 0-12 |
Geology 8a Give the classification of meteorites. How does the study of meteorites help in understanding the internal composition of the Earth? UPSC 2018, 20 Marks
Geology 8b Illustrate different type of mass wasting processes with suitable examples. Enumerate preventive measures for the mitigation of hazards from mass wasting. UPSC 2018, 20 Marks
Geology 8c What are the sources of groundwater pollution? Suggest preventive measures to control groundwater contamination. UPSC 2018, 10 Marks