Peninsular Plateau And Its Characteristics
The peninsular plateau is a part of the peninsular Indian landmass that is surrounded by seas. Most of the peninsular landmass is a plateau. It's an uplifted block called the Horst, created by two faults in the west and east coasts. It is triangular in shape with its three corners at:
- Bharuch in Gujarat on the west
- Rajmahal hills on the east
- Kanyakumari in the south
The Narmada - Son - Damodar rift valley runs across the peninsular landmass cutting it into two parts viz., the Central Highlands in the north, and the Deccan Plateau in the south.
The peninsular plateau is divided into various regional landmasses based on the local topography and their geographical location. They include:
- Malwa plateau
- Bundelkhand plateau
- Baghelkhand plateau
- Madhya Bharat Pathar
- Kathiawar plateau
- Chotanagpur plateau
- Meghalaya plateau
- Deccan plateau
- Located immediately to the east of the Aravallis, most of the plateau is situated in Madhya Pradesh and Rajasthan
- Narmada Rift Valley is the most prominent structure of this plateau
- It has the drainage systems of the Bay of Bengal (Chambal, Sindh, Betwa, Parbati join the Yamuna, which in turn joins the Ganga) and the Arabian Sea (Narmada, Tapti, Mahi).
- The average elevation of the plateau is 500m with a gentle slope towards the north.
- Geologically, it's among India's most diverse landmasses with Dharwar rocks, Vindhyan rocks, Gondwana rocks, and Volcanic Basalt being found within it.
- It has semi-arid to arid type of climate. Short spells of rainfall occur due to convection which gives rise to temporary streams. In the absence of dense vegetation, these streams remove the topsoil giving rise to narrow valley type of structures known as Gullies. Gullies deepen eventually to form Ravines.
- Ravine-Gully erosion turns the landform into a Badland, not suitable for agriculture. Chambal's drainage basin is abundant with such Badland topography.
- Lies to the east of Malwa plateau, and is situated in the states of Madhya Pradesh and Uttar Pradesh.
- Situated over the Ganga basin, made up of granite and gneiss rocks
- The average elevation of the plateau is in the range of 300-600m.
- It has a drainage system into the Bay of Bengal.
- Along the Betwa floodplains, there are badlands which make the region unfit for agriculture.
- It is situated in three States - UP, MP, and Chhattisgarh
- Son river drains the region, on which the Rihand Dam and Govind Vallabh Pant Sagar reservoir (largest manmade lake in India) were built.
- The plateau contains Dharwar and Gondwana rocks.
- It separates the Ganga basin from the Mahanadi basin.
Madhya Bharat Pathar
- Also known as the Central Highland
- It contains the drainage of river Chambal which flows in a rift valley. Kali-Sindh, Banas, and Parbati are the tributaries of Chambal which also drain the region.
- It lies to the east of Marwar upland
- Located in the Kathiawar region of Gujarat, this region has many pipe-like volcanic openings which gave rise to many hill ranges such as the Girnar range, Junagarh range, Pavagarh range etc.
- Lake Nalsarovar, which is a bird sanctuary, forms the Northeast boundary of the plateau.
- Little Rann is situated to the north of Kathiwar plateau.
- It has some volcanic rocks in the form of Mandav hills and Balda hills.
- Mt.Girnar is the highest point of Kathiawar plateau.
Chota Nagpur plateau (CNP)
- It's a continental plateau, with Himalayas (Shiwaliks) to its north, and having the drainage systems of Damodar, Suvarnarekha, North Koel, and South Koel which empty into the Bay of Bengal. Himalayan uplift resulted in the down buckling of the plateau which created a trough in which the alluvial sediments from the Himalayan rivers got deposited. This includes the present day Ganga basin.
- Its average elevation is in the range of 600-700 m above the mean sea level.
- The plateau covers the States of Jharkhand, parts of Chhattisgarh, West Bengal, Bihar, and Odisha.
- Geologically, the plateau is made up of Dharwar (igneous and metamorphic) rocks, mostly granite and gneiss.
- Damodar rift valley (DRV) is the most prominent structure of this plateau. Gondwana rocks are found in the rift valley, which resulted in some of the richest coal deposits of India viz., the Damodar Valley Coal Fields.
- Dalma Hills and Dhanjor hills, which are among the oldest volcanic hills in India, are a part of the plateau.
- The region comprised of alternate soft and hard rock strata. This resulted in the differential weathering and erosion of the soft rock strata, leaving the hard rock strata. Such a topography is known as the Patland.
- The Damodar rift valley divides the plateau into two parts. The Patlands south of DRV constitute the Ranchi plateau, and the Patlands north of DRV make up the Hazaribagh plateau.
- Due to intense weathering and erosion, CNP is covered with laterite soils.
- CNP is among the richest mineralized zones of India. Many important industrial centres such as Jamshedpur, Bokaro, Sindri, Lohar Darga, Ranchi etc. are located in this region.
- Rajmahal hills form the eastern edge of the CNP.
- Also known as the Shillong plateau, it's a part of the peninsular plateau but is separated from it by the Malda trough/Rajmahal-Garo gap.
- It is made up of Dharwar and Gondwana rocks. It is rich in coal fields (Bapung coal fields of Meghalaya) and also in nuclear minerals (Uranium deposits of Domiasiat mines in Meghalaya)
- Garo, Khasi, and Jaintia hills form the southern edges of the plateau.
- Its average elevation is about 1500m above the mean sea level.
- Brahmaputra's basin is to the north of the plateau. River Surma enters the plateau from Assam and joins the river Meghna in Bangladesh.
- Cherrapunji and Mawsynram, located in the Khasi hills, are the wettest places in India and are a part of the plateau.
- It is the largest plateau in India, covering an area of around 5 lakh sq.km
- It extends into the States of Maharashtra, Telangana, Northern Karnataka, and Kathiawar region of Gujarat
- It is volcanic plateau formed after the solidification of basaltic lava which has flown over the region in layers forming a step-like topography known as the Deccan Traps.
- Deccan Traps have the highest thickness in the west and gradually slope towards the east.
- The western edge of the plateau is made up hills with steeping slopes to the west, known as the Sahyadris. They are a part of the Western Ghats.
- The plateau comprises several hill ranges such as the Balaghat hills, Ajanta hills etc.
- Gaps in these hill ranges are known as passes. For example, the Bhorghat pass connects Mumbai and Pune.
The southern extensions of Deccan plateau are known by their regional names such as the Telangana plateau and Karnataka plateau
- It is made up of Dharwar rocks. Gondwana rocks are also found in the Godavari valley, famous for its coal fields.
- Godavari, Krishna, and Penna are the major rivers flowing through the plateau.
- Because of the Dharwar rock strata, the plateau is rich in mineral resources.
- The plateau receives good rainfall (average of 100mm/year), similar to the CNP.
- It's considered to be a peneplain i.e., a vast featureless, undulating plain.
- The average elevation of the plateau is in the range of 500-600m above the mean sea level
- Also known as the Mysore plateau.
- The average elevation of the plateau is in the range of 600-900m.
- The plateau has two major divisions viz., Malnad and Maidan
- Malnad is a hilly region covered with dense forests. Maidan is a rolling plain with low lying hills.
- The plateau is drained by numerous streams and rivers flowing from the Western Ghats.
- The plateau tapers to the south, in between the Western and the Eastern Ghats, and merges with the Nilgiris.