There is heterogeneity in the structure and composition of rocks. The plateau lying east of Aravalli is made up of sandstones, shales and limestone. Granitic rocks are exposed in the north central part which is called Bundelkhand. The area covered with basalt is called the Malwa. The region has a series of flat topped plateaus where the Vindhyan rocks are spread horizontally.
The plateau slopes gently to the Ganga plain and is drained by a number of streams i.e. Chambal, Betwa, Sind and Ken. Chambal the largest river rises at a height of 854 metres in the Vindhya Range. It joins Yamuna below Etawah. The Aravalli range about 160 km. wide starts from the north of the Gujrat plain and continues for about 725 km upto Delhi.
Mt. Abu is the highest peak having height of 1722 metres above sea level. Strong blasts of South-West wind (in the summer season) carry sand through the gaps in the broken northern Aravalli range and deposit them on the eastern side of the range resulting in the infertility of southern part of Haryana and Mathura district of U.P.
The Aravalli range consists of highly compressed and metamorphosed argillaceous rocks. Soft rocks have been eroded away leaving behind valleys. The valleys are separated by ridges of relatively hard rocks. Intrusion of grantes is a common feature in the Aravalli range.
Climate and Vegetation:
There is diversity in climate in this region. The area west of Chambal experiences tropical and sub-tropical climate and that east of Chambal has humid sub-tropical with dry winters. Monsoon savanna prevails in the Malwa plateau. There is diversity in vegetation due to diverse climate. The dry savanna is distributed in the eastern Rajasthan and tropical dry deciduous vegetation at other places.
Mostly rain-fed crops are grown in this region and only lava plateau and parts of river valley are covered with fertile alluvium. Forest covers hills and the eastern part of the region.
There is negative land causing 38 per cent of the surface under crops and only 10 per cent area cropped more than once.
The semi-arid area in the north-west grows mainly jowar and bajra as kharif crops, and barley, gram and wheat as Rabi crops. Rapeseed and sesamum are also raised. In the lava area where rain-fall conditions are more favourable and soils fertile wheat is significant. Sagar and Vidisha (Bhilsa) districts in particular are important for the production of wheat. Wheat occupies half of their land.
In the eastern part of this region where annual rainfall is between 106 cm. and 122 cm. rice is an important kharif crop and wheat a Rabi crop. Pulse, however, leads all other crops. In the relatively wet south-east lac and tendu leaves are collected by the people to supplement their income.
There is a difference in the crop pattern of the semi-arid northern range and wet and stony southern Aravalli range. In northern Aravalli-range there is a large area under alluvial soil of which 52 percent is under crops. Bajra is the leading crops. In the southern part of Aravalli range only 22 per cent of the land is under cultivation. Bajra is significant. Maize is the leading crop in the hilly belt. It occupies about 1/3rd of the total cropped area.
The Chambal Valley below Kota forms a fertile alluvial plain. The irrigation project was undertaken during 1953-54, to bring prosperity to this area. The construction of three dams and a barrage across the Chambal have been completed. It is convenient to construct dams across the river between Chowrasigarh and Kota because of the fact that the river flows through a gorge between these two places.
The Gandhi Sagar Dam, which is at a site 8 km. downstream from Chowrasigarh Fort, has a power station of 116 mw. The second dam, the Rana Pratap Sagar Dam is situated at a distance of about 33 km. further downstream near Rawat Bhatta in Rajasthan having capacity of 172 mw.
It provides irrigation to 1.22 lakh hectares of land. The third dam, the Kota dam, is situated at a distance of about 16 km. above Kota town having a capacity of 99 mw of power. The Kota Barrage is located near Kota from where an alluvial plain runs along the river. The barrage diverts the water released by the above mentioned dams, for irrigation.
There is an extensive quarrying of limestone and sandstone in the unmetamorphosed sedimentary Vindhayan rocks. Limestone is quarried near Satna and Maihar in the east. Makrana near Sambhar Lake produces the finest white marble of very fine crystals in India. Panna in Madhya Pradesh is known for producing industrial and other diamonds.
Mining is confined to a diamond bearing volcanic pipe in which the diamonds occur as crystals. The operations of the mines are carried on by open pit methods.
There is important led and zinc mine at Zawar in Udaipur district. Another zinc lead ore mine is being developed at Rajpura Dariba. The lead concentrates are sent to Tundu (near Dhanbad) where they are smelted for lead.
There are large deposits of copper ore available near Khetri. A large copper complex which is a mining- cum-metallurgical one has come up at Khetri.
Sambhar Lake in this region is famous for salt. The salt dust carried by south west monsoon winds is deposited in the form of sheet of shallow water covering an area measuring 233 square km. This lake produces about one-eight of the total salt produced in the country. Rock phosphate also occurs at Jamarkotra near Udaipur.
Cotton textile is the leading industries of this region at the location like Indore, Ujjain, Gwalior, Bhopal, Dewas, Ratlam and Mandsore and Bhilwara.
Kota is an important industrial centre which derives power from Chambal valley projects. The largest nylon plant of India is located here. Cement is manufactured at Satna, Sawai Madhopur and Lakheri.
There is a fully mechanised marble mine at Nizrana in Udaipur district. Tiles and slabs of marble and granite are made on a large scale near Udaipur town.
There is a currency printing press at dewas. Aluminium wires, copper wires, transformers and parts of switchgears are produced at Chhatarpur.
A fertiliser plant based on natural gas from Hajira is being established at Bijaipur.
The district densities are, however, higher in the narrow belt forming the northern margin of this region. Here densities are relatively high mainly because of the high productivity of the soil. The southern hilly area has large number of scheduled tribes population. Jaipur is the only capital city in this region. Beside it Ajmer, Kota, Indore, Gwalior, Bhopal, Alwar and Ujjain are other towns of this region.