Kerala Plus One Answer Key 2025 Geology

ANSWER KEY
I
FIRST YEAR HIG HER SECONDARY EXAMINATION MARCH 2025

Part III
SUBJECT: GEOLOGy

CODE No: try g"t VERSION:&
SCORES:6Ct
2 HOURS
Qn Sub alue Points,/Indicators Score Total
No
Score
Section I
1
1 I
2 9a o.l d.t i 1 1
3 Geoid
1 1
4 35
1 1
5
1 1

5X 1 5
Section II
6 a Root
1 2
b ual soil 1
7 a Load 1 2
b Erosion
1
8 a
1 2
bRu 1
9 a Palaeontol is the of fossils 1 2
b is the of rocks
10
I
a Water table -the upper surface of the zone of 1 2
saturation.
b I(arst topography- resul tan t topography produced
by 1
the action of wa ter
11 a Sea cliff- verrical or near vertical rock exposure
1 2
along coastal zone result from weathering and
erosion.
b Coral re ef- h uge I lme stone structu res built by
CC rtain 1
called co rals.
l2 llvidences in su ort of continental d rift-fit of 2 2

con tal margins-s imilari ty of rock seq uences and
D
fea tures- fossil evidences palaeoclima ri C

6X2=12
Section III
13 maj or geological orga nrzatlons- Ge ological
3
Survey of I nd la ( G S r) A governmen t o rgan,z'
a tion
for cond ucting geological surveys and studies.
oil and N atural G as Corporation ( o N GC) I t
conducts explora tion and prod uction activities
ln
India of crude o il and na tural
8as.
ation al Cen tre for Earth Sciences
S tud ies
(N CE S S ) The primary objecti
VE of CES S is to
ote modern S cientific and technologi
cal
research to the coun try in general and Kerala
t4 big bang hypotheses-universe was concentrated
3 3
ata single point. 'l'he universe expanded rapidly
a tremendous explosion, the universe had
cooled enough that protons, neutrons, and
electrons
form.Proto galaxies and within them the
earliest stars are formed. Both time
and space were
created in event.
15 Types of mass wasting-cree p falls
topples, 3 3
slides, flows , landslides t a valanc hes
and
subsidence.
16 a Defla tion hollows-d epression formed in barren 1 3
unconsolidated materials by deflation
action of
wind.
b Loes s bt anket like aeol ian de posi ts formed
W hen 1
the finest particl CS of d us t silt an
d clay tra velling
settle d own
c Barchans-cre scent shaped sand dunes -convex 1
iowards wind ward side.
17 e atures of glacial
erosion -cirque- a semicircula r or
bow I 3
shaped depressi on presen t at
.ralley head in a laciated the
I mountain. arete- knife
forme d W hen two ue s me e t .horn it

Lj c''
L:

lsa formed W hen three or more ues meet.
^ 1B F orma of res id ual mountains- formed when the 3 3
mad e up of softer rocks are worn out,
whe reas e made u p of harder rocks are

fold mountains- folding of strata, accompanied by
general uplift and consequent erosion.
mountains- built up by the accumulations of
materials around the vents of volcanoes.
5X3= 15
Section IV
79 a
b
I 4
of re 1
c
1
d
20 J-ayered internal structure of the earth- four
I
layers 4 4
the crust-thin -sial and sima
the mantle-thick -upro 2900 km
outer core -in molten state _iron and nickei
inner core- dense and hot+Marked diagram
27 a Poros ty the a moun t o f oPe nlngs pres en t in a 2 4
ock.
Permea biliry-number: of inter connected pore
spaces
in rock formation.
b Stalactite -a column of calcium carbonate 2
ievelops, hanging downward from the roof
the
avern.
S talagmi te- column o f cal
cl um carbonate S tarts
to u from the fl o or o f the cavern
22 an floor sffucture-the topography of
the 4 4
ocean floor is diverse-divided - inio
definite
Continental shelf- gently sloping submerged
surface extending from the shoreline
continental srope-the steep gradienr thar leads
to the deep-ocean floor
Dee ocean flo or-contains a a number of

ni
'->l i. -"

dis topographic units such as abyssal
plains & hills, mid-oceanic ridges,island
arch,d oceanic trenches,seamounts & guyots

23 tures of Convergent plate modon-Convergent 4 4
plate margins are those margins where two plates
moving towards one another. Here plate destruction
. Three rypes are convergent boundaries are
le. Oceanic-Oceanic Convergence forming
island arcs-Oceanic-Continental Convergence
forming volcanic arcs and continent-continent
Convergence forming tectonic mountains.

4X4-16
Section V
24 Classification of earrh processes -traditionally 3 6
grouped into two-
ternal processes -diastrophism, magmatism ,

External and
Types of chemical weathering -rocks are broken 3
down by chemical alteration of minerals.Types_
tion, oxidation, carbonation,hydrolysis,hydration
and spheroidal weathering.
25 a Stream vall eys- narrow e longa te d V shaped val leys
2 6
by rive r
Water falls-formed by differential erosion by a
stream
b broad sweeplng CU rVCS found along the 4
e of a stream. + diagram
Oxbow lakes -cu t off meanders later occupied by
WA ter*
26 Physical properties of minerals properties which
can 6 6
be observa b le directly Important ph ysical properties
Habit- p hys ical characte ristic or make u p of a
mineral.
Colour-contributes com tion and of

tt )

url
Streak- of its fine powder.
stre-shining of mineral.
Cleavage-tendency to break with smooth planes
Fracture-nature of broken surfaces.
ness-the resistance which the mineral offers to
scratching.
Transparency-ability to transmit light.
VI heaviness of a mineral.
2X6-12
Grand Total 60/7s

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