MBOSE Class 12 Question Paper 2022 for Geology

Total No. of Printed Pages—8
HS/XII/Sc/Gl/22

2022

GEOLOGY
(Theory)

Full Marks : 70

Time : 3 hours

The figures in the margin indicate full marks for the questions

General Instructions :

(i) Write all the answers in the Answer Script.

(ii) Attempt Part—A (Objective Questions) serially.

(iii) Attempt all parts of a question together at one place.

( PART : A—OBJECTIVE )
( Marks : 35 )

1. Choose and write the correct answer of any six of the
following : 1×6=6

(a) Decomposition is associated with

(i) physical weathering

(ii) chemical weathering

(iii) organic weathering

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( 2 )

(b) Organisms that swim about in ocean water are said
to be
(i) planktonic
(ii) nektonic
(iii) benthonic

(c) The Disang group is observed in the stratigraphy of
(i) Assam
(ii) Meghalaya
(iii) Spiti

(d) Galena is the ore of
(i) iron
(ii) lead
(iii) zinc

(e) Marine organic animals give rise to
(i) coal
(ii) water
(iii) petroleum

(f) Ore deposits formed at the same time as the
enclosing rocks are said to be
(i) syngenetic
(ii) epigenetic
(iii) metamorphic

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( 3 )

(g) Which of the following is an ore of aluminium?
(i) Bauxite
(ii) Hematite
(iii) Coal

(h) Diamond bearing conglomerates were reported in the
(i) Dharwar supergroup
(ii) Vindhyan supergroup
(iii) Paleozoic of Spiti

(i) Acid rain is associated with
(i) overground coal mining
(ii) underground coal mining
(iii) overground Pb-Zn mining

2. State whether the following statements are ‘ True’
or ‘False’ (any six) : 1×6=6

(a) Dihing Group is younger than the Disang Group in
Upper Assam.

(b) Ores from which several metals can be extracted are
called complex ores.

(c) Sands range in size from 4 mm to 1/16 mm.

(d) Muds are argillaceous materials.

(e) Pallial line is seen in lamellibranchs.

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( 4 )

(f) The brachiopods evolved earlier than the gastropods.

(g) Closepet granite is associated with the stratigraphy
of Meghalaya.

(h) The hot residual fluid containing minerals after the
main minerals have crystallized out is called
hydrothermal fluid.

(i) To mitigate the effect of earthquakes, buildings are
to be constructed on soil.

3. Fill in the blanks (any six) : 1×6=6

(a) Water bearing formations in the earth are called _____.

(b) Wavy features on the top of sedimentary layers are
called _____.

(c) Rocks of Archean age over which all other rocks are
laid down/formed later is called the _____.

(d) The ‘angle of rest’ for a safe hill slope should
not exceed ______°.

(e) Lung diseases in miners are associated with _____
mining.

(f) _____ coal is with over 90% carbon.

(g) The ease with which water moves through a medium
is called _____.

(h) Petroleum is of _____ origin.

(i) The Barail Group is followed immediately upwards
by the _____ Group.

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( 5 )

4. Express each of the following in 1 (one) word (any five) :
1×5=5

(a) Rocks where oil accumulates

(b) Lessening of the hazards of natural earth processes

(c) Level below which actual groundwater occurs and
the pores completely saturated with water

(d) Place where organism, past or present, live

(e) Transformation of loose sediments into hard lithified
rock

(f) Natural earth process that brings loss of life and
property

(g) Useless minerals

5. Match Column—A with Column—B and write the
corresponding numbers : 1×6=6

Column—A Column—B
(a) Bed load (i) Gondwana
(b) Glossopteris (ii) Spiti
(c) Placer (iii) Assam
(d) Otoceras (iv) Deposition
(e) Landslides (v) Wet soil
(f) Conglomerate (vi) Mechanical concentration
(vii) Rudaceous
(viii) Transportation

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( 6 )

6. Write on the following in 1 (one) or 2 (two) line(s)
(any six) : 1×6=6
(a) Dorsal side
(b) Mud crack
(c) Non-clastic sediments
(d) Ore
(e) Mould
(f) Vertebraria
(g) Nodule
(h) Definition of groundwater

( PART : B—DESCRIPTIVE )
( Marks : 35 )

Answer five questions, selecting one from each Group

GROUP—A
( Sedimentology )

7. Write a brief note on the common sedimentary structures
with neat sketches. 7

8. Write on any two of the following : 3½×2=7
(a) Diagenesis
(b) Grain size and the size scale
(c) Clastic and non-clastic sedimentary rocks

9. Give a classification of the environments of deposition
with very brief explanation on each of them. 7

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( 7 )

GROUP—B
( Paleontology )

10. Outline the morphology of a typical brachiopod shell
with suitable sketches. 7

11. Write on any two of the following : 3½×2=7
(a) Index fossil
(b) Fossils and correlation
(c) Suture and types of suture in cephalopods

12. Write a note on the coiling of gastropods and the
different coiling patterns observed in gastropods. 7

GROUP—C
( Stratigraphy )

13. Write the lithostratigraphy of Meghalaya in tabular form
with very brief petrographic note of each unit. 7

14. Write on any two of the following : 3½×2=7
(a) Barail group
(b) Correlation
(c) Intrusives into the Dharwar Supergroup

15. Write a petrographic description of the Lower Triassic
rocks of Spiti. 7

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( 8 )

GROUP—D
( Mineral and Energy Resources )

16. Outline the formation of coal. 7

17. Write on any two of the following : 3½×2=7
(a) Classification of magmatic ore deposits
(b) Lead deposits in India
(c) Distribution of radioactive minerals in India

18. Write an account on the origin and distribution of
chromite in India. 7

GROUP—E
( Engineering Geology, Groundwater, Environment
and Disaster Studies )

19. Write on the various causes of landslides. 7

20. Write on any two of the following : 3½×2=7
(a) Environmental impact of open-cast mining
(b) Porosity and permeability
(c) Mitigation of earthquakes

21. Explain how sedimentary rock structures have an
influence on dam stability with sketches. 7

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HS/XII/Sc/Gl/22/58 22K—60