Northern Plateau of Odisha

Introduction and Extent

The Northern Plateau of Odisha forms the northeastern extension of the Chotanagpur Plateau and occupies the districts of Sundargarh, northern parts of Jharsuguda, and portions of Sambalpur and Keonjhar. This region is a highly dissected tableland ranging in elevation from 500 to 1,000 metres above sea level. It represents the oldest geological formation in Odisha, composed primarily of Archaean crystalline rocks — gneisses, granites, and schists — over which younger sedimentary formations have been deposited in isolated basins. The plateau slopes gently from north to south, influencing the drainage pattern of the major rivers that originate in this region.

Geological Structure and Landforms

The region is characterised by rugged topography with numerous hill ranges, isolated residual hills, and intervening valleys. Prominent hill ranges include the Bonai Hills, the Sundargarh Hills, and the Bamra Highlands. The Brahmani, Sankh, and Koel rivers have carved deep gorges through the hard crystalline rocks, creating spectacular landscapes. The plateau surface is littered with inselbergs — isolated rocky knolls that have resisted weathering. The region also contains several intermontane basins where coal-bearing Gondwana sediments were deposited, most notably the Ib Valley and Talcher coalfields. The extensive laterite capping is a common feature of the plateau top.

Drainage Patterns

The Northern Plateau serves as a major watershed for several important rivers. The Brahmani River originates near Rourkela at the confluence of the Sankh and Koel rivers. The Sankh rises in the Chotanagpur region and flows south-southeast, while the Koel originates in the same region and flows southwest before meeting the Sankh near Rourkela. The Mahanadi and its major tributaries — the Ib and the Tel — also traverse portions of this plateau. The drainage pattern is predominantly dendritic, reflecting the uniform resistance of the crystalline rocks. During the monsoon, these rivers swell considerably, causing erosion and transporting large quantities of sediment downstream.

Mineral Wealth and Economic Importance

The Northern Plateau is the mineral powerhouse of Odisha. Sundargarh district alone possesses substantial reserves of iron ore, manganese, limestone, and dolomite. The iron ore mines at Kiriburu, Meghahatuburu, and Bolani are located along the Odisha-Jharkhand border. The Ib Valley coalfield, with its vast reserves of thermal-grade coal, has made Jharsuguda a hub for thermal power generation. The presence of these minerals has attracted heavy industries — Rourkela Steel Plant, one of India’s first integrated steel facilities, was established here in 1955 precisely because of proximity to raw materials.

Tribes and Human Settlement

The Northern Plateau is home to a significant tribal population, including the Munda, Oraon, Kharia, and Kisan communities. These groups have traditionally practised agriculture on the plateau slopes and supplemented their livelihoods through forest produce collection. The dense sal forests that once covered much of this region have been degraded in many areas due to mining and industrial development. However, the Government has implemented several afforestation and social forestry programmes in the mining belts. The region’s population density is moderate, with urban centres concentrated around industrial townships like Rourkela, Rajgangpur, and Jharsuguda.