GEOL/II/EC/03 Student's Copy
2 0 1 8
CBCS
2nd Semester
GEOLOGY
SECOND PAPER
Petrology and Geochemistry
Full Marks 75
Time 3 hours
PART A—OBJECTIVE
Marks 25
The figures in the margin indicate full marks for the questions
SECTION—A
Marks 10
Tick the correct answer in the brackets provided 1×10=10
1. Magma, having more than 65% silica, is
basaltic magma
granitic magma
andesitic magma
basic magma
2. The oceanic crust is mainly made up of
granite
dunite
syenite
basalt
3. Weathering due to the precipitation and growth of salt crystals near rock
surface is
forest wedging
carbonation hydrolysis
efflorescence
exfoliation
/317 1 Contd.
4. Which of the following is in the correct order of increasing grain size?
Silt, Clay, Cobble, Pebble, Sand, Boulder
Clay, Silt, Sand, Cobble, Pebble, Boulder
Clay, Silt, Sand, Pebble, Cobble, Boulder
Clay, Silt, Pebble, Sand, Boulder, Cobble
5. Mylonite is a metamorphic rock formed due to
thermal metamorphism
cataplastic metamorphism
metasomatism
Both and
6. Blueschist facies has
high temperature and low pressure
very high temperature
low pressure and low temperature
low temperature and very high pressure
7. Rate of denudation is
faster than rate of uplift
lower than rate of uplift
approximately equal to rate of uplift
None of the above
8. For porphyry copper deposits, path finder element is
Fe
Mo
Ag
Au
9. Which of the following instruments produces very high resolution images of
a sample revealing details less than 1 nm?
XRD
XRF
SEM
ICPMS
GEOL/II/EC/03/317 2 Contd.
10. Preparation of flat and polished section of the sample is required in
electron microprobe
SEM
TEM
XRD
SECTION—B
Marks 15
Write notes on the following, taking one from each Unit 3×5=15
Unit—I
1. Petrography and petrogenesis
2. Dykes and sills
Unit—II
3. Biological weathering
4. Breccia and conglomerates
Unit—III
5. Foliation
6. Metamorphic textures
Unit—IV
7. Oddo-Harkins rule
8. Clarke value
Unit—V
9. Principle of XRF
10. Sample preparation of electron microprobe
PART B—DESCRIPTIVE
Marks 50
The figures in the margin indicate full marks for the questions
Answer five questions, taking one from each Unit
Unit—I
1. Write detailed notes on any two of the following 5×2=10
Forms of igneous rocks
Bowen's reaction series
Structure of igneous rocks
GEOL/II/EC/03/317 3 Contd.
2. Discuss the different types of magma and write notes on any two of the
following
Petrographic description of Peridotite
Petrographic description of Gabbro
Petrographic description of Trachyte
Unit—II
3. Write detailed notes on the formation of sedimentary rocks. 10
4. Write notes on any two of the following 5×2=10
Primary sedimentary structures
Petrography of Limestone
Petrography of Shale
Unit—III
5. Define the term 'metamorphism' and write detailed notes on the different
agents of metamorphism and zones of metamorphism.
6. Write notes on the following 5×2=10
Thermal metamorphism
Zone of metamorphism
Unit—IV
7. Write a note on the types of meteorites. 10
8. Write notes on any two of the following 5×2=10
Geochemical classification of elements
Primary and secondary dispersion of elements
Principle of diadochic replacement
Unit—V
9. Write the principle and application of XRD.
Write the sample preparation of ICP-MS. 5
10. Write the principle, sample preparation and application of electron
microprobe.
Write a note on application of XRF. 3