The Peninsular Plateau

• Peninsular Plateau is the largest physiographic unit of India, stretching from Aravallis in the north-west to the Shillong plateau in the north-east and Kanyakumari in the south. It is triangular in shape. 
• It occupies 50% of the Indian landmass, consisting of numerous small plateaus and mountains measuring around 16 lakh square km. 
• It is an ancient tabular block containing Archean Gneiss, Schist and the Dharwar rock system. In the Deccan plateau, igneous Basalt rocks are also found.
• It is among India’s oldest and most stable landmass. It has undergone minimal structural changes since its formation. It has never been submerged beneath the sea except in the few places where marine transgressions have been made, and that too locally. Along with that, it has not experienced any tectonic activity except for Bhima Fault formed along the Bhima river.
• Due to old age, the rivers in this region attained their base level and developed broad and shallow valleys. 
• Plateau’s general elevation is from west to east, also vouched by the river movement (except in the Narmada-Tapi rift valley).

• The entire peninsular plateau was formed during the pre-Cambrian era, i.e., 500 MYA (Million Years Ago).
• Later, the Indo-Australian plate (containing Peninsular Plateau) started to move towards the Eurasian plate. Around 70 MYA during the tertiary period, it passed over the Reunion hotspot, and highly fluid basaltic lava broke through the surface, forming a basalt flood province called Deccan Traps. 

The entire Peninsular Plateau consists of several smaller plateaus and hill ranges.

• It lies in the north-western part of the Peninsular Plateau. It lies to the south-east of Aravallis and north of Vindhyachal Range. 
• Chambal, Betwa and Ken drain the Malwa Plateau before joining the river Yamuna.
• It consists of an extensive lava flow, thus covered with black soils.
• It is devoid of vegetation, and due to gully erosion by rivers like Chambal, deep ravines have developed, and the region has been made unfit for agriculture, converting it into Badlands. 

• It is a part of the Peninsular Plateau, which extends east of the Malwa Plateau and is known as Bundelkhand.
• It lies in Madhya Pradesh & Uttar Pradesh.
• It has an average elevation of 300-600 m 
• It is made up of Granite & Gneiss rocks.
• It is a drought-prone region.
• River streams such as Betwa and Ken flow through it. The erosional work of these rivers has converted this region into an undulating (wave-like) area.

• Bagelkhand lies to the east of Bundelkhand. 
• It is made up of limestone and sandstone.
• It is drained by Son and Mahanadi rivers.  
• The general elevation is between 150 m to 1,200 m.

• The Chhattisgarh Plain is the only plain region in the Peninsular plateau that is worth naming.
• It lies between Maikal Range and Odisha Hills. 
• It is saucer-shaped and is drained by the Mahanadi River.
• The general elevation is between 250-330 m. 

a. Maharashtra Plateau 

• It lies in Maharashtra and forms the northern part of the Deccan Plateau.
• It is formed due to fissure eruption and lava flow. Hence, most of the rocks of this region are basaltic rocks of lava origin.
• It has ‘step-like topography‘ due to horizontal lava sheets. Hence, it is also known as ‘Deccan Traps.”
• Maharashtra Plateau has ‘Black Soil’, also known as ‘Regur’. It is well suited for the cultivation of Cotton.
• Important rivers of south India like Godavari, Bhima, Krishna, Vardha and Venganga flow through it. The erosional activity of these rivers has converted the region into a number of shallow and broad valleys flanked by flat-topped steep-sided hills and ridges. E.g., Godavari flows between Satmala and Balaghat.

b. Karnataka Plateau

• It lies to the south of the Maharashtra plateau. 
• It is also known as Mysore Plateau.
• The general elevation is between 600-900 m.
• It is primarily made up of Archean formations.
• Karnataka plateau has two parts, Malnad and Maidan.
  1. Malnad means ‘Hilly and Forested land.’
  2. Maidan means ‘plains’. It is a rolling plain made up of granite. 

• The famous Baba Budan hills lie in the Malnad region, and it is renowned for its coffee plantation (the famous Café Coffee Day chain is based here).
• The region is highly dissected by the fast-moving rivers emerging from the Western Ghats.
• River Kaveri originates from the Malnad. It jumps from Malnad to Maidan to make the famous Shivsamudram Falls. Here, river Kaveri has two islands, i.e. Shivsamudram Island and Srirangapatnam Island (famous for the Treaty of Srirangapatnam). The lake between the two islands is known as Ranganathitoo Bird Sanctuary. Due to excessive water, the Shivsamudram region is famous for sugarcane.
• River Tungabhadra (a tributary of Krishna) also originates from the Malnad region. 

c. Telangana and Rayalaseema Plateau

• It is made up of Archean Gneiss with an average elevation of 500-600 m.
• This region is semi-arid as it lies in the rain-shadow zone of the western and eastern ghats.
• It is a highly dissected region by the rivers passing through this region, i.e. Godavari, Krishna and Penneru.

d. Dandakaranya Plateau

• It is the mineral-rich region of Chhattisgarh and Odisha, touching parts of Maharashtra.
• It is drained by the Indravati river.
• Richest mines of India are found in Dandakaranya Plateau
• It is badly affected by naxalism and is a part of the ‘Red Corridor.’

• It is the north-east extension of the Peninsular Plateau.
• It is separated from the Peninsular Plateau by Rajmahal -Garo Gap / Malda Gap. It is formed by the down-faulting, which was later filled by the sediments of river Ganga and its tributaries. 
• This region is made up of Dharwar rocks of the Archean Rock System, shales and schists with granite intrusions.
• Coal, iron ore, sillimanite, limestone, uranium, and other minerals are abundant in the Meghalaya Plateau.
• The Meghalaya Plateau is divided into numerous hills such as Garo, Khasi, Jaintia, Barail and Mikir Rengma (Karbi-Anglong Plateau). Out of all, Khasi is the highest. Shillong, situated in the Khasi hills, is the highest point of the Meghalaya Plateau.
• This region receives ample rainfall from the south-west monsoon. The Meghalaya plateau has severely degraded as a result. Chirapunji exhibits a barren rocky surface devoid of any vegetation.

• It extends from Gujarat (Jobat) to Bihar (Sasaram).
• It has an average elevation of 450 to 600m.
• It is a BLOCK MOUNTAIN formed due to rifting. The southern boundary of the Malwa Plateau has escarped downwards due to faulting, and as a result, a block mountain and rift valley have formed. Vindhya is the block mountain (horst), while in the adjoining rift valley (graben), the Narmada river flows towards the west.
• Vindhyas act as the ‘Water divide of India.’    
• It is a source of many north-flowing rivers like Chambal, Sindh, Betwa & Ken ( tributaries of Yamuna).
• It contains limestone and marble (property of the Vindhyan System of rocks).
• Kaimur Range is an extension of Vindhyas.

• Satpuras are a series of seven-block mountains (Sat = 7 and Pura = Mountains). It is not a continuous range in contrast to Vindhyas. 
• They run in the west-to-east direction, starting from Rajpipla Hills (Gujarat) to Gawilgarh (Maharashtra), followed by Mahadev Hills (Madhya Pradesh)and ending with the Maikal Hills (Chhattisgarh). 
• It runs through Gujarat, Maharashtra, Madhya Pradesh and Chhattisgarh. 
• It forms the boundary between Maharashtra and Madhya Pradesh and between Maharashtra and Gujarat.
• Dhupgarh near Panchmarhi in Mahadeo Hills is the highest peak of Satpuras. 
• Important rivers like Narmada, Son and Tapi originate from Satpuras.
  • Narmada and Son originate from Amarkantak 
  • Tapi originates from a place known as ‘Multai’.
  • Narmada flows in the rift valley between Vindhyas and Satpuras, while Tapi flows south of Satpuras.
  • Both Narmada and Tapi are west-flowing rivers in contrast to all other peninsular rivers, which are east-flowing.
• Amarkantak, situated in the Maikal Hills of Satpura, is important as 
  • Rivers Narmada and Son originate here. It represents an example of ‘radial drainage’.
  • Famous Amarkantak Biosphere Reserve (famous for Tigers) is situated here.
• Important fauna of the region includes Tigers, Elephants, Barasingha, Black Panther etc.
• Important tribes of the Satpuras include Khonds, Mundas and Bhils. 
• It has great economic importance.
  • Tropical Deciduous Forests of Satpura provide the best grade teak in the world apart from Sal and Tendu (minor forest produce).
  • The paper industry of India is concentrated in this region. Vallabhgarh, which is the largest paper mill in Asia, is situated in this region.

• The Eastern Ghats are a series of discontinuous hills starting from the Vaigai river in Tamil Nadu to the Mahanadi River in Odisha.
• There is no structural and geological homogeneity. All the hills have formed in different geological events. 
•  Eastern Ghats consists of (from south to north)
  • Shevaroy and Javadi in Tamil Nadu
  • Palconda and Nallamalai in Andhra Pradesh 
  • Garjat in Odisha
• They are cut by four major rivers of South India, i.e. Godavari, Krishna, Kaveri & Mahanadi.
• Eastern Ghats are much older than Western Ghats.
• They are not as high as the Western Ghats. 
• The highest peak of Eastern Ghats is Mahendragiri (in Garjat Hills) 
• They receive lesser rainfall than the Western Ghats. Hence, the vegetation of this region is Tropical Deciduous.