CS (main) EXAM, 2010

GEOLOGY
Paper II
ln,ne Allov.,ed Three Hours( f Maxi1ni11n Marks ... 3001
INSTRUCTIONS
. Each question is print??d both in Hindi and in
English.
A11.nvers nzust be written in the 1nedium
specified in the Admission Certificate issued
to you, lvhiclz niust be stated clearly on the
cover of the answer-book in the space
provided for the purpose. No niarks will be
given for the answers written in a medium
othe,: than that specified in the Admission
Certificate ..
Candidates should attempf Question Nos. 1
and 5 which are co,npulsory. and any three
of the ren1aining questions selecting at least ..
011e question froni each Section.
Candidates should draw diagra,ns wherever
necessary.
· All questions carry equal marks.

. .
Section
l.· Attempt the following in about 150 words each
4x15=60
What is chemical equilibrium With suitable example, explain the consequence . of disturbance. of the equilibrium state in rocks .
Explain how on the bases of chemistry and optical properties, the various feldspars differ from one another.
How does oxygen in atmosphere differ from oxygen in rocks and minerals 7
Can ice be called a mineral 4
Can a glacier be called a rock 4
Discuss the factors that control melting temperature in igneous rocks. How magmas of different composition evolve?

2. Discuss with sketches: 3x20=60
Double refraction
Determination of optic sign of biaxial minerals
Symmetry elements in crystals


3. What is the difference between bio-genous and terrigenous sedilnents? 5
Why is burial necessary. to form a sedimentary rock 5
Why are most beds of sedimentary ·rocks formed horizontally 5
How are the provenances. of. heavy minerals in sedimentary rocks identified 5
What are the effects of temperature, confining pressure and different stresses on metamorphic minerals and textures of metamorphism in
rocks What are the different sources of heat for metamorphim 20
What are the differences between 20
cleavage and external crystal fonn and
colour and streak of a mineral

4. What do mud cracks tell about the environment of deposition of a sedimentary rock? How does a graded bed form. How does a sedimentary braccia differ in appearance and origin from a conglomerate What is an "Evaporite deposit"' and· how does it form? 30

What role do gases ·play in volcanisrn What does "Pillow Structures" indicate about the environment of vorcanism What detemines
the viscosity of a lava? Why are extrusive Focks fine grained 30

Section
5. Answer the following in about 150 words each
4x15=60
What is "Tenor" of an ore? What are "Assay Width" and "Average Width" of an ore body? State different methods of mine sampling.
How does sampling help in determination of ore reserve
What are the different types of mineral deposits, where Magnetic Self-potential Resistivity and Gravity methods of
Geophysical prospecting are applied.
·Briefly explain the laws of isomorphous substitution of elements and give examples wherever necessary.
How do earthquakes cause tsunami

6. Compare the lithological associations of sedimentary and magmatic iron ore deposits. Name the locations of these two types of
deposits found in lndia. Describe the geology, mineralogy and mode of formati on of any important sedimentary iron ore deposit of India. 30
How oil and natural gas form in nature What geologic factors make them an economically exploitable reserve. Briefl y describe the
hydrocarbon occurrences in the Bombay High. 30

7 . Distinguish between contac t metamorphic and contact metasomatic ore deposits. Give Indian examples of such deposits. How does porphyry copper deposits form in nature. Add a note on Malanjkhand copper ore deposit. 30
Enumerate in detail hydrogeochemical and biogeochemical prospecting methods . How Pedogeochemical prospecting helps in prospecting mineral deposits Add a note on geochemical sampling . 30

8. Describe in details the cosmic abundance of elements. 30
Why solifluction· more · common in· cold climates than in temperate. climates Name and explain the key factors that control Mass
Wasting. ·what role does water play in various types of Mass ·wasting 30