They originate in Gujarat (at Palanpur) and extend till Haryana. They terminate in the Delhi ridge.
They have a maximum extent of 800 km
They are old fold mountain ranges, one of the oldest tectonic mountains in the world.
Rocks that make up the Aravallis are more than 2 billion years old.
Unlike other fold mountains, Aravallis have an average elevation in the range of 400-600m only. This is because throughout their geological history they were subjected to the processes of weathering and erosion.
Only a few peaks reach an elevation of above 1000m. These include – Mt. Gurushikhar (1722m, the highest point of Aravallis), Mt.Abu (1158m, it’s part of a plateau).
Geologically, they are mainly made up of Dharwar igneous and metamorphic rocks.
They contain the largest marble deposits in India.
Rivers Banas, Luni, Sabarmati are born in Aravallis. Banas is a tributary of Chambal. Luni is an ephemeral river that terminates in the Rann of Kutch.
They contain several passes that cut through them, especially between Udaipur and Ajmer like Piplighat, Dewair, Desuri, etc.
They also contain several lakes such as Lake Sambhar (largest inland saline water body in India), Lake Dhebar (south of Aravallis), Lake Jaisamand (in the Jaisamand wildlife sanctuary), etc.
Vindhyan range
These are non-tectonic mountains, they were formed not because of plate collision but because of the downward faulting of the Narmada Rift Valley (NRV) to their south.
They extend for 1200km from Bharuch in Gujarat to Sasaram in Bihar.
Geologically, they are younger than Aravallis and Satpura hills.
Their average height is in the range of 300-650m.
They are made up of older Proterozoic rocks. They are cut across by Kimberlite piles (diamond deposits)
They are known by local names such as Panna, Kaimur, Rewa, etc.
They rise from the NRV in the form of steep, sharp slopes called the escarpments. These escarpments are well developed in Kaimur and Panna regions.
Satpura range
Satpura range is a combination of Satpura, Mahadeo, and Maikala hills.
Satpura hills are tectonic mountains, formed about 1.6 billion years ago, as a result of folding and structural uplift. They are a Horst landform.
They run for a distance of about 900km.
Mahadeo hills lie to the east of Satpura hills. Pachmarhi is the highest point of the Satpura range. Dhupgarh (1350m) is the highest peak of Pachmarhi.
Maikala hills lie to the east of Mahadeo hills. Amarkantak plateau is a part of the Maikala hills. It is about 1127m.
The plateau has the drainage systems of Narmada and Son, hence it has drainage into the Bay of Bengal as well as the Arabian sea.
These are mostly situated in the States of Madhya Pradesh and Chhattisgarh.
These hills are rich in bauxite, due to the presence of Gondwana rocks.
Dhuandhar waterfalls over the Narmada is situated in MP.
