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Geography

 

Geography of India

 

Geological History of India

Precambrian Era

  • Indian Peninsular plate =Oldest crustal block of India
  • Collision between 3 proto continents
  1. Aravalli
  2. Dharwad
  3. Singhbhum

 

 

 

 

 

Geological History of India

PreCambrian Era

3 lineaments

  1. Narmada
  2. Son
  3. Godavari Remnants:

Aravalli Range , Dharwad plateau,

Singhbhum plateau

 

 

 

Geological History of India

Geosynclines at margins of Protocontinents:

  1. Aravalli
  2. Vindhyan
  3. Satpura
  4. Eastern Ghats
  5. Bijawal

 

 

 

 

 

Geological History of India – Gondwana

  • Reactivation of Narmada – Son-

Godavari lineament

  • Rifting of Mahanadi and Damodar valley
  • Submergence of forests-Led to the development of coalfields

 

 

 

 

 

 

Geological History of India

  • Faulting along western edge of peninsular plateau

 

 

 

 

 

 

 

 

Geological History of India

  • 150 million years ago Indian plate broke from Gondwanaland
  • Started northward journey towards Eurasian Plate
  • 15 million years ago India broke from Madagascar

 

 

 

 

Geological History of India

Late Cretaceous

  • India moves over Reunion Islands
  • Hotspot volcanism
  • Deccan lava plateau
  • Narrowing of Tethys sea

 

 

 

 

 

 

Geological History of India

Tertiary Period

  • Collision between Indian plate and Eurasian plate
  • Upliftment of Himalayas

 

 

 

 

Geological History of India

  • The jerk – activation of crack created at western margin of

peninsula

  • Breaking of western part – subsidence – peninsula raised at western side
  • Tilted in west-east direction
  • Western ghats = horst

 

 

 

 

Geological History of India

  • Late Pleistocene – formation of

Northern plains

  • Sediments from Himalayan rivers

 

 

 

 

 

Physiography of India

Himalayas         

  • Youngest and loftiest fold mountains in the world
  • Stretch for a distance of over 2400 km from Nanga Parbat to Namcha Barwa.
  • Width varies from 500 km in Kashmir to 200 km in Arunachal Pradesh.

 

 


Division of the Himalayas

 

  • Shiwalik or Outer Himalayas
  • Himachal or Middle Himalayas
  • Himadri or Greater Himalayas

Shiwaliks      

  • Width of the Shiwaliks varies from 50 km in Himachal Pradesh to less than 15 km in Arunachal Pradesh.
  • It is an almost unbroken succession of low hills except for a gap of 80 -90 km which is occupied by the valley of the Tista and Raidak Rivers.
  • Altitude varies from 600m – 1500 mm. Formation of Duns and Duars ● Hogback appearance.
  • Eastern part of Shiwalik up to Nepal is covered in thick forests but forest cover becomes thin in the west.
  • Seasonal streams called Chos in Punjab and Himalayas dissect these mountains.

Middle or Lesser Himalayas  

  • 60-80 km wide with elevation varying from 3500-4500m.
  • Hogback appearance
  • Important ranges – Pir Panjal, Dhaula Dhar, Mussoorie, Nag Tibba, Mahabharat range
  • Pir Panjal Range extends from Jhelum to Upper Beas River for 300-400km and is separated from the Zaskar Range by the valley of Kashmir.
  • Famous hill stations – Shimla, Ranikhet, Mussoorie, Nainital, Almora and Darjeeling.

Great Himalayas    

  • Average elevation of 6100 m and an average width of 25 km.
  • It is about 150 km from the northern edge of the plains of Northern India.
  • Highest peak in the world – Mount Everest (Sagarmatha or Chomlungma) is located here.
  • 14 peaks above 8000 m.
  • Cannot be easily crossed even through passes because they are generally higher than 4,570 m above sea level and remain snowbound for most of the year.

 

Trans Himalayas      

  • Ranges directly north of the Himalayas – Zaskar, Ladakh, Kailash and Karakoram.
  • Karakoram stretches for about 1000 km in the east-west direction. Its average elevation is 3000 m above msl. It is home to the second highest peak called Godwin Austen or K2.
  • Karakoram is of volcanic origin.

 

Purvanchal or Eastern Hills

 

  • Southward bend of Himalayas extending from Arunachal to Mizoram.
  • Form boundary with Myanmar
  • Differ in scale of relief and in their morphology from Himalayas.
  • Patkai Bum (2000-3000m), Naga Hills where Mt. Saramati is highest peak.
  • Manipur Hills (2500 m), Mizo Hills

(average elevation 1500m)

Regional Division of the Himalayas

 

 

Punjab Himalayas

  • 560 km from Indus to Satluj River.
  • It is also called Kashmir and Himachal himalayas
  • Karakoram, Ladakh, Pir Panjal, Zaskar and Dhaula Dhar are the main ranges in this region.
  • General elevation falls westwards.

Kumaon Himalayas  

  • 320 km between Satluj and Kali Rivers
  • Sources of Ganga and Yamuna are located in these Himalayas
  • Several duns are located in these Himalayas

Nepal Himalayas             

  • 800 km between Kali and Teesta river.
  • Tallest section of the Himalayas – Mount Everest, Khangchendzonga, Lhotse, Dhaula Giri are important peaks.

Assam Himalayas 

  • Tista to Brahmaputra Gorge for 750 km.
  • Lesser Himalayas are very narrow and close o the Great Himalayas.
Glaciers in the Himalayas

 

Glaciers

  • Out of 5 lakh square km, about 33,000 sq km is covered by snow.
  • There are about 15,000 glaciers in the Himalayas lying between the two syntaxial bends
  • The glaciers extend down to 3695 m in Sikkim and 3660 m in Kumaon but can descend to 2500m in Kashmir- distance from equator, eastern Himalayas rise abruptly from the plains.

Important Glaciers   

  • Karakoram – Siachen, Fedchenko, Hispar, Baltoro, Chogo lungma etc.
  • Himalayas – Sonapani, Bara Shigri, Gangotri, Milam, Satopanth, Rongbuk, Zemu, Kanchenjunga, Khumbu, Kangshung etc.

 

Passes in the Himalayas
                       

Significance of the Himalayas

  • Climate influence
  • Defence
  • Source of freshwater
  • Fertile Soil
  • Hydroelectricity
  • Forest wealth
  • Agriculture
  • Tourism
  • Pilgrimage
  • Mineral wealth

Northern Plains   

  • Depositional plain formed by the work of three river systems – Indus, Ganga and Brahmaputra.
  • Largest alluvial tract in the world extending for a length of 3200 km from the mouth of the Indus to the mouth of the Ganges.
  • Its average width varies from 150 – 300 km. It is widest in the west where it stretches for about 500 km. Its width decreases in the East – Prayagraj (280 km), Rajmahal Hills (160 km). It widens to about 460 km in West Bengal but narrows down in Assam to 60 -100 km Maximum depth of alluvium is up to 6100 m.
  • Average elevation is 200m and highest point is 291 m between Ambala and Saharanpur – forming the water divide between Ganga and Indus.
Geomorphology of the Plain  
                                   

Bhabhar

  • Narrow ,        8-16 km    continually from Indus to Tista.
  • Alluvial fans are formed.
  • High porosity and  rivers disappear.
  • Narrow in the east and extensive in the west.
  • Not suitable for tree or agriculture growth.

 

Geomorphology of the Plains                                   

Tarai

  • 15-30 km wide, marshy tract south of the Bhabhar
  • Streams re-emerge
  • Ill drained and covered with thick forests and variety of wildlife.
  • Tarai is more marked in the East due to high rainfall
  • Most of it has been cleared for agriculture in PB, UK and UP

 

Geomorphology of the Plains                                   

Bhangar

  • Old alluvium, concentration of kanker – calcareous deposits
  • Old flood plains, higher level

 

 

 

Geomorphology of the Plains         
                         

Khadar

  • New floodplains,
  • alluvium renewed every year.

 

Regional Division of the Great Plains 
  • Rajasthan Plains
  • Punjab – Haryana Plains
  • Ganga Plains
  • Brahmaputra Plains

Rajasthan Plains 

  • Western extremity consists of the Thar Desert which is about 650 km long and 250-300 km wide.
  • Eastern part of the Thar desert upto the Aravali Range is a semi-arid plain which is called Rajasthan Bagar. It runs in NE – SW direction from the edge of the Aravali in the east to the 25 cm isohyet in the west. Luni river flows through this region.
  • Agricultural tracts in this region are few and are called rohi. The tract north of the Luni is called thali or sandy plain.

Punjab – Haryana Plain   

  • 640km NW -SE direction. It is about 300 km wide.
  • Average elevation is about 250 m above msl.
  • Its eastern boundary is marked by Yamuna in Haryana.
  • It is formed by the depositional work of Indus and its tributaries.
  • It is primarily made up of doabs.
  • Northern part of the plain has been extensively eroded by numerous streams called Chos.
  • The area between Ghaggar and Yamuna rivers lies in Haryana and is called the Haryana tract.
Important Doabs

  • Bist – Jalandhar Doab between Beas and Satluj
  • Bari Doab , between Beas and

Ravi

  • Rachna Doab, between Ravi and Chenab
  • Chaj Doab between Chenab and Jhelum
  • Sind Sagar Doab between JhelumChenab and Indus rivers
Ganga Plain        
                

Upper Ganga

  • Ganga, Yamuna, Ramganga, Sarda, Gomati and Ghaghra

Rivers

  • Western part consists of Ganga Yamuna Doab
  • Eastern part – Rohilkhand Plains which merge into the Awadh

Plains

 

Ganga Plains

Middle Ganga Plain

  • Eastern part of UP and Bihar
  • 600 km in East – West direction
  • Drained by Kosi, Ghaghra, Gandak, Son river.
  • Ganga – Ghaghra Doab, Ghaghra Gandak Doab, Gandak -Kosi doab

(Mithila Plain)

Lower Ganga Plain

  • Kishenganj Tehsil of Purnia, West Bengal and Bangladesh.
  • Foot of Darjeeling Himalayas to the BoB.
  • Largest delta in the World
  • Sunderbans forests are present here.
Brahmaputra Plains    
  • Extending from easternmost end of Assam to Dhubri it is about 720 km long and its average width is about 60-100 km.
  • Several tributaries of Brahmaputra debouch abruptly in the main valley and create a number of fans.
  • Large number of ox bow lakes, meanders are created. Majuli Island

 

Significance of the Plains

  • Agriculture – Punjab and Haryana

– granary of India ● Settlements

  • Religious places

 

 

 

Peninsular Plateau

  • Roughly triangular in shape with apex near Kanyakumari and base at the edge of the

Northern Plains.

  • Surrounded by hill ranges on all three sides – Aravali, Vindhya , Satpura and Rajmahal in the North,            Western        ghats  and     Eastern Ghats in the West and East respectively.
  • 1600 km N-S, 1400 km W-E
  • Average height is 600-900 m above msl. Ancient          tabular          block  composed of

Archaean gneisses and schists.

 

Plateaus of Peninsular India

Marwar Upland

  • East of Aravali with average elevation of 250-500 m and it slopes down eastwards
  • Banas river (trib. Of Chambal) flows through this region.
  • Eroded by     Banas       and  its tributaries into a rolling plain.

Central Highland

  • East of Marwar Upland.
  • Basin of Chambal river (rift valley)
  • Thick forests grow here. To the north are ravines and badlands of Chambal river.

Plateaus of Peninsular India    

South of yamuna river between Central Highlands and Vindhyan scarp

.Bundelkhand Upland

  • Spread over UP and MP
  • It slopes northward
  • Betwa, Dhasan and Ken have carved out deep gorges.
  • NW, NW – covered by alluvium and in SW by Deccan Trap
  • Erosional work has rendered it unfit for cultivation

Malwa Plateau

  • Triangle – Vindhyan Hills, Aravali Range, scarp overlooking

Bundelkhand.

  • Two systems of drainage – Arabian Sea (Narmada and Tapi), BoB

(Chambal and Betwa)

  • Composed of extensive lava flows and is covered with black soils. Flat topped hills and in the north

Chambal ravines.

 

Plateaus of Peninsular India    


Baghelkhand

  • East of Maikala Range made of limestones and sandstones in the west and granite in the east.
  • Central part acts as water divide between Son and Mahanadi
  • General elevation of 150 -1200 m and uneven relief.

Chotanagpur Plateau

  • East of Baghelkhand Average elevation of 700m.
  • Composed of Gondwana rocks, Archean granite and gneisses and Deccan lavas.
  • Highest elevation found in the Pat lands.
  • Radial drainage system
  • Major rivers – Damodar, Subarnarekha, N&S Koel and Barakar.
  • Mineral Heartland of India.

 

Plateaus of Peninsular India    

North of Damodar river with average elevation of 600 m above msl.

Hazaribagh Plateau

  • Parasnath hill rises up to 1366 m.
  • Area is made of granites and gneisses while hills have quartz rocks.

Ranchi Plateau

  • South of Damodar Valley rises to about 600 m above msl.
  • Maximum height is found in western parts
  • Netarhat Pat and Goru rise up to 1119m and 1142 m respectively.
  • At places it is interrupted by monadnocks and conical hills.

 

Plateaus of Peninsular India                                     

Deccan Plateau

  1. Maharashtra Plateau – underlain by basaltic rocks of lava origin. Area looks like a rolling plain due to weathering. Broad and shallow valleys of Godavari, Bhima and Krishna are found. Entire area is covered by black cotton soil.
  2. Karnataka Plateau – Divided into two parts – Malnad and Maidan. Malnad is dissected into deep valleys and covered with dense forests. Maidan on the other hand is formed of rolling plain with low granite hills.
  3. Telangana Plateau – It is drained by Godavari, Krishna and Penneru river systems. It is divided into two regions – Ghats and Peneplains.
Plateaus of Peninsular India

 

Meghalaya Plateau

  • Separated from main block by GaroRajmahal Gap (Malda Gap).
  • This gap was formed by down faulting and later filled by Alluvium
  • It slopes down to the Brahmaputra valley in the North and Surma and Meghna valleys in the south.
  • IT consists of Garo, Khasi-Jaintia Hills and Mikir Hills.
  • Shillong is the highest point on the plateau at 1961 m.

Plains of Peninsular India

Chhattisgarh Plain

  • Saucer shaped depression drained by Upper Mahanadi.
  • Whole basin lies between Maikala Range and Odisha hills.
  • Region was once ruled by Haithaivanshi Rajputs from whose thirty six forts it derives its name.
Hills of Peninsular India

 

  • Aravali Range
  • Vindhyan Range
  • Satpura Range
  • Western Ghats/Sahyadri
  • Eastern Ghats
  • Rajmahal Hills

 

Passes of Peninsular India

 

  • Goram Ghat and Haldi Ghati inAravali
  • Thal Ghat, Bhor Ghat and Pal
  • Ghat important passes inSahayadris
  • Asirgarh pass in Satpura Range
Significance of Peninsular India 
  • Mineral Wealth
  • Hydroelectricity
  • Crops
  • Biodiversity
  • Tourism

Coastal Plains

Western Coastal Plains  

  • Kachchh Peninsula
  • Kathiawar Peninsula
  • Gujarat Plain Konkan Plain
  • Karnataka Coastal Plain
  • Kerala Plain / Malabar Plain

 

 

 

 

Eastern Coastal Plains 

  • Utkal Plain
  • Andhra Plain
  • Tamil Nadu Plain
  • Northern Circars – Mahanadi and Krishna
  • Carnatic – Krishna and Cauvery

 

Island Groups

Andaman and Nicobar Islands

 

 

  • 6 degrees and 45 minutes N – 13 degrees 45 minutes north
  • 265 big and small islands extending up to 590 km.
  • Andaman group is separated by Ten Degree Channel from the Nicobar Group.
  • Great Nicobar is only 147 km away from

Sumatra

  • Barren and Narcondam are volcanic.
  • Saddle Peak is the highest peak
Lakshadweep Islands

 

  • 8 degrees North to 12 degrees 20 minutes north.
  • Islands North of 11 degrees North are called Amindivi islands and to the south are called Cannanore islands.
  • Largest islands is Minicoy island.
  • They are of coral origin.
  • Nine degree channel separates Minicoy from the rest.