Goa Board Class 12 Question Paper June 2018 Geology _New Pattern_

2018 VI 13 1430 Seat No. :

Time : 21/2 Hours GEOLOGY (new Pattern)
(History and Political Science)

Subject Code

H 7 0 6

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

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

1. A) Complete the following statement by choosing the alternative given below
The metamorphic rock that shows composite foliation is
• Marble
• Slate
• Banded hematite quartzite
• Gneiss.
B) State the term used for the grain size of sandstone. [1]
C) Which igneous rock shows orientation of laths of plagioclase felspars in the
direction of lava flow ? State the type of texture involved in the rock. [2]

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D) Explain the terms schistosity and gneissosity in the metamorphic rocks. [2]
OR
D) Explain the terms clastic and crystalline in the sedimentary rocks. [2]
E) Based on silica percentage and grain size distinguish between [2]
• Basalt and Dunite.
F) Write short notes on : [3]
• Temperature as an agent of metamorphism.
• Rudaceous sedimentary rocks.

2. A) Complete the following statement by choosing the alternative given below
the statement and write the completed statement : [1]
To obtain a rock sample from the mantle, drilling will be done through oceanic
crust rather than through continental crust because
• Continental crust is softer than the oceanic crust.
• Continental crust is thinner than the oceanic crust.
• Oceanic crust is thicker than the continental crust.
• Oceanic crust is thinner than the continental crust.
B) What is the term used for the largest tragment that are blown out during an
volcanic eruption ? [1]
C) Write a note on ‘Stromboli Volcano’. [2]
D) Define hypocentre of an earthquake. Which type of seismic waves are
generated at the hypocentre ? [2]
E) Explain, with an example the various geological features formed during the
collision of two oceanic plates. [2]
F) Explain the following : [3]
• Seismic discontinuities.
• Block mountains.
OR
F) Explain the following : [3]
• Shadow zone.
• Dome mountains.
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3. A) Complete the following statement by choosing the alternative given below
the statement and write the completed statement : [1]
The vertical distance between the crest and the trough of a fold is known as
• Axis
• Amplitude
• Width
• Wavelength
B) What are slickensides ? [1]
C) With neat labelled diagram explain the following : [2]
• Master Joint
• Strike Joint
D) State and explain the various terms for a bed resulting from its unequal
uplift. [2]
E) Write a note on recumbent fold. [2]
F) With neat labelled diagram explain the movement of hanging wall in the
various types of faults. [3]
OR
F) With neat labelled diagram explain the older series in the various types of
unconformities. [3]

4. A) Complete the following statement by choosing the alternative given below
the statement and write the completed statement :
The crystals of mineral beryl occurs in association with ______________ [1]
• Lead deposits
• Pegmatite deposits
• Copper deposits
• Mica deposits.
B) State the chemical composition of mineral chalcopyrite. [1]
C) Define ore. Where does the lead-zinc ore mineralisation occur in
Rajasthan ? [2]
D) Explain any three vein type of hydrothermal deposits. [3]
E) Explain the following : [4]
• Generation of coal.
• Stratigraphic succession of Goa.
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5. A) Complete the following statement by choosing the alternative given below
The Mahadeva group belong to _______________
• Dharwar supergroup
• Vindhyan supergroup
• Gondwana supergroup
• Cuddapah supergroup
B) State the fundamental lithostratigraphic unit. [1]
C) Which era marks the begining of lava flow in peninsular indica ? State the
type of lava flowed in the eruption. [2]
D) When does the standard geological time scale began ? State the various
eons and eras of the standard geological time scale. [3]
E) Explain the various principles of stratigraphy. [4]
OR
E) Explain the various modes of preservation of fossils.

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