2. Content
Introduction
Lithology
Distribution
Classification
Fossils of siwalik
Vertebrate Fossil
Importance of siwalik super group
SIGNIFICANCE
Bibilography
3. Introduction
The Siwalik group is a thick sedimentary sequence, which
extends throughout the East-West of the Southern
Himalayan belt that represents the youngest mountain belt,
and is bounded by the main Boundary thrust in the North
and the Himalayan frontal thrust in the south and is
separated from the lesser Himalaya in the north and the
indo Gangetic plain in the south.
The sediments of the siwalik group were deposited in a
foreland basin of the Himalayas between middle Miocene to
lower Pleistocene
The name siwalik was originally given by captain P.T Cautely
in 1832.
4. Lithology
The Siwalik system is a great thickness of detrital of rocks such as
coarsely bedded sandstones, sand rocks, clays and conglomerates
measuring between 4500 – 5200 meters in thickness.
The bulk of the formation as already stated is very closely similar to the
materials constituting the modern alluvia of river except that the
former is somewhat compacted has undergone folding and faulting
movements, and is now resting at higher levels with high angles of dip.
The lithology of the Siwaliks suggests their origin; they are chiefly the
water –worn debris of the granitic core of the central Himalya ,
deposited in the long and broad valley of the “siwalik river” .
The Siwalik rocks are involved in the Himalayan orogeny, they are
folded, faulted and even overturned and thrusted.
5. Distribution
The siwalik hills are located in the political
boundaries of Pakistan, India, Nepal and Bhutan
and range between 6 to 90 km in width.
They gradually become steeper and narrower in
relief and width respectively, from northern
Pakistan to Bhutan( over 2000 km in length) .
7. Siwalik group in India
1. Jammu and Kashmir:
Complete development of Siwalik can be seen in Jammu hills
2. Himachal Pradesh:
Siwalik group in Himachal Himalya from a parallel foothill belt along
the southern margin between Ravi and Yamuna river.
3. Uttararkhand:
Kalagarh basin
4. West Bengal:
In the Terai region of the northern part of Jalpaiguri and Darjleeing
district of West Bengal
5. Assam:
Cachar hills
6.Arunachal Pradesh:
Mishmi hills
8. Classification
On Palaeontological grounds the systems is divisible into
3 sections, the passage of the one into the other division
being, however quite gradual and transitional.
One of the basis vertebrate Fauna the siwalik group has
been classified into three divisions:
1. Upper siwalik
2. Middle siwalik
3. Lower siwalik
9. Division Formation Lithology Age
Upper Siwalik
(2000-2500 m)
Middle Siwalik
(2000 m)
Lower Siwalik
(1000- 3000m)
Boulder
Conglomerate
Pinjor Formation
Tatrot Formation
Dhokpathan
Formation
Nagri Formation
Chinji Formation
Kamlial Formation
Conglomerate, thick
earth clays, Loose
sands,grits,sandstones,S
oft sandstones,
Grey and white
sandstones and sand
rock with shales and
clays of pale and drab
colours.
Massive compact and
hard sanstones shales.
Bright red nodular
shales and clays with
fewer grey sansdtones
Dark, hard sandstones
and red and purple
shales and pseudo-
conglomerates.
Lower Pleistocene
to Lower Pliocene
Pontain to Middle
Miocene
Middle Miocene .
Tortonian
Helvetian
10. Upper siwalik
Boulder conglomerate :
This formation is made of mainly boulder conglomerate, granite,
quartzites ,slates and limestone.
Pinjor formation:
This formation is composed of conglomerates, coarse grits and
sandstone clay.
Tatrot formation:
This formation rests on unconformably over the Dhokpathan
rocks
It is composed of soft massive sandstones, silts, clays and
conglomerates.
11. Middle siwalik
Dhokpathan formation:
It is the most important fossil bearing formation of the siwalik
group
This formation is made of brown sandstones, gravel beds, shales
and clays.
Nagri formation:
It is composed mainly of massive grey sandstone with some
shales.
This formation is rather poor in fosslis.
12. Lower siwalik
Chinji formation:
This formation is composed of 400 to 1800 metres thick beds of
red nodular shales and clay with some sandstone and
conglomerates.
Kamlial formation:
The formation rest over the Muree group of lower Miocene age.
It is composed of red sandstones with nodules of clay(pseudo-
conglomerates) and purple shales.
Thickness is 600 to 1000 metres .
13. Fossils Of siwalik
1.Upper siwalik:
i. 1. Primates – Simia , Semnopithecus, Papio
ii. 2. Carnivores – Hyaenrctos, Sivalenis,Mellivora, Mustela,
Lutra, Canis,Vulpes, Hyaena, Crocuta
iii. 3. Elephants – Mastodon, Sivalensis , Stegodon, Ganes
iv. 4. Ungulates – Rhinoceros Palaeindicus, Equuss Sivalemsis,
Susfalconeri, Hippopotamus, Cervus, Bucapra, Anoa
19. Vertebrate fossils
Fossils are disarticulated in nature.
Most durable parts are commonly preserved as
fossils of vertebrates are their bones,teeths and their
footprints.
A rich assemblage of fossil has been recovered from
the Siwalik rock which has given this system a very
important status in Indian startigraphy. Most of the
stages in Siwalik system are typically rich in
mammalian fossils.
20. Geo world Heritage site of Siwalik Himachal
Pradesh Suketi fossil National park
•Image sources
•https://i0.wp.com/thejerker.com/wp-content/uploads/2021/06/suketi2.jpg?w=650&ssl=1
21. Importance Of Siwalik Supergroup
• The Siwalik supergroup has huge deposits of
calcium,carbonate and of important minerals
such as iron,sulfur and copper; the deposits
however,are generally of sub-economic grades
that currently are not worth exploting.
22. Significance
1. Evolution of different modern species.
2. Useful for correlation purpose in continental region.
3. History and culture.
4. Paleoclimatology,paleobiogeography and paleoecology.
23. BIBLIOGRAPHY :
1. GEOLOGY OF INDIA BY – D.N. WADIA
2. A TEXTBOOK OF ENGINEERING GEOLOGY
BY- K.M. BANGAR
