Paper: IAS Mains Previous Year Paper Geology (1990)

Paper-I- Geology-1990 (Mains)

SECTION A

1. Explain any three of the following in about 200 words each:

(a) Petro fabric analysis as a tool in structural studies

(b) Drainage patterns

(c) Origin of continents and oceans

(d) Products of volcanic eruptions

2. Write a short essay on ‘Geomorphic features of the Indian sub-continent’.

3. (a) What are joints? How do they differ from faults? Give a genetic and geometrical classification of joints.

(b) How does the repetition of beds differ due to folding and faulting?

4. Distinguish between the members of the following pairs:

(a) Bedding Plane and Cleavage

(b) Esker and Kame

(c) Horst and Graben

(d) P-waves and S-waves

(e) Solution valley and Glacial valley

SECTION B

5. Answer any three of the following in about 200 words:

(a) Extinction of Dinosaurs

(b) Evidences of first marine transgression in South India during mesozoic and related stratigraphic unit / units.

(c) Permian-Triassic Boundary

(d) Microfossils and their significance

6. Give in a tabular form the stratigraphic succession, lithology and characteristic fossils of the Siwalik System. Discuss the conditions of deposition and climatic factors during that period.

7. Draw a neat, full-page-size labelled diagram in illustrate the external morphology of:

(a) a Gastropod

(b) Trilobita Name two genera, from each of the above groups from Indian stratigraphy mentioning their stratigraphic horizon.

8. Discuss the following:

(a) Gondwana flora climatic vicissitudes and stratigraphic classification of the supergroup

(b) Recent developments in Dharwarian stratigraphy

Paper-II- Geology-1990 (Mains)

SECTION A

1. Write notes on any three of the following in about 200 words each:

(a) International system of crystallographic solution

(b) Use of stereographic projections to represent symmetry

(c) Biaxial indicatrix

(d) Ionic radii coordination number

2. Discuss in detail application of X-rays for crystal studies.

3. What is the difference between pleochroic and interference colors ? Explain how these colors are produced in minerals.

4. Give an account of the physical, chemical and optical properties of pyroxene group of minerals.

SECTION B

5. Write notes on any three of the following in about 200 words each:

(a) Facies and grades of metamorphism

(b) Metallogenetic epochs

(c) Bowen’s Reaction in Principle

(d) Ore dressing and benefication

6. Give a brief account of the oil and gas fields of India with particular reference to post-independence discoveries.

7. Give an account of textures present in sedimentary rocks and discuss their significance.

8. Discuss in detail the use of aerial photographs in geological investigations.