Goa Board Class 12 Question Paper Mar 2018 Geology _New Pattern_

2018 III 13 1000 Seat No. :

Time : 2½ Hours GEOLOGY (New Pattern)

Subject Code

H 7 0 6

Total No. of Questions : 5 (Printed Pages : 4) Maximum Marks : 55

INSTRUCTIONS : i) All questions are compulsory.
ii) Answer each question on a fresh page.
iii) Figures to the right indicate full marks.
iv) Draw neat labelled diagrams wherever necessary.
v) Answers to the questions carrying 1 mark should be written
in 1 to 10 words.
vi) Answers to the questions carrying 2 marks should be written
in about 50 words.
vii) Answer to the questions carrying 3 marks should be written
in about 80 words.
viii) Answers to the questions carrying 4 marks should be written
in about 120 words.
ix) Select the correct alternative for the multiple choice
questions and rewrite the statement.

1. A) Complete the following statement by choosing the alternative given below the

The splitting and the northward drift of the Peninsular India from the Gondwana
land occurred during _________
• Early Cretaceous
• Mid Miocene
• Late Permian
• Early Triassic

B) State the landform formed when two continental plates diverge. [1]

C) How are Residual mountains formed ? [2]

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D) Explain in brief, how did Mariana islands originated. [2]

E) Write a note on magnitude of an earthquake. [2]
OR
Write a note on shadow zone of an earthquake. [2]
F) Explain the various types of central type of volcanoes. [3]
2. A) Complete the following statement by choosing the alternative given below the
The rock surface showing displacement on either side is known as ________
• Step Zone
• Shear Zone
• Fault Zone
• Slickensides
B) State the symbolic form of the shale bed that strikes N50º W and dips 30º due
NE. [1]
C) With neat labelled diagram explain the formation of disconformity. [2]
D) Write a note on genetic classification of Joints. [2]
E) Beds of sandstone, shale and limestone are underlained by granite. State
and explain the structural geological feature formed above. [2]
F) With neat labelled diagram explain the following : [3]
• Throw and heave
• Fan fold
OR
With neat labelled diagram explain the following : [3]
• Horst and graben
• Symmetrical anticline.
3. A) Complete the following statement by choosing the alternative given below the
The index mineral which is an indicative of high grade metamorphism is ____
• Biotite
• Talc
• Hypersthene
• Chlorite
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B) State the most abundant mineral found in ultramafic igneous rock. [1]

C) How does the crystallisation of minerals occur from cooling magma as per
Bowens Reaction Series ? [2]

D) Write short notes on : [2]
• Clastic rocks
• Carbonate rocks.

E) Explain the role of temperature as an agent of metamorphism. [2]

F) Explain the classification of sedimentary rocks based on their mode of
accumulation. [3]
OR

Explain the classification of igneous rocks based on mineral composition. [3]

4. A) Complete the following statement by choosing the alternative given below the

The emergence of land plants occurred during _______
• Paleogene period
• Cambrian period
• Silurian period
• Carboniferous period

B) What is the term used in stratigraphy for matching the rock stratas with
reference to their ages from different places ? [1]

C) “Shale bed is overlained by Sandstone, and Limestone in a sedimentary
basin and intruded by a pegmatite dyke”. State and explain the principle of
stratigraphy. [2]

D) State the classification of Dharwar, Cuddapah and Vindhyan Supergroups. [3]

E) Explain the various modes of preservation of fossils. [4]

P.T.O.
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5. A) Complete the following statement by choosing the alternative given below the
statement and write the completed statement :

The metals that are mined from the Zawar area of Rajasthan are _______ [1]
• Fe and Al
• Cu and Zn
• Pb and Zn
• Fe and Mn

B) What is the term used for rocky material found in association with ores ? [1]

C) How is coal formed ? [2]

D) Explain the following : [3]
• Syngenetic deposits
• Fissure veins
• Saddle reefs.

E) Explain the following : [4]
• Magmatic segregations
• Indian distribution of chromium ores.
OR

Explain the following : [4]
• Magmatic disseminations
• Indian distribution of Aluminium ores.

______________

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