The Chota Nagpur Plateau consists of three steps. The highest step is in the western part of the plateau, where
pats as a plateau is locally called, are above sea level. The highest point is . The next part contains larger portions of the old Ranchi and Hazaribagh districts and some parts of old Palamu district, before these were broken up into smaller administrative units. The general height is . The topography in undulating with prominent gneissic hills, often dome-like in outline. The lowest step of the plateau is at an average level of around . It covers the old Manbhum and Singhbhum districts. High hills are a striking part of this section –
Parasnath Hills rise to a height of and
Dalma Hills to . Examples include Netarhat Pat, Jamira Pat, Khamar Pat, Rudni Pat and others. The area is also referred to as Western Ranchi Plateau. It is believed to be composed of
Deccan basalt lava.
Ranchi Plateau in the plateau The Ranchi Plateau is the largest part of the Chota Nagpur Plateau. The elevation of the plateau surface in this part is about and gradually slopes down towards south-east into the hilly and undulating region of Singhbhum (earlier the Singhbhum district or what is now the
Kolhan division). The plateau is highly dissected. The
Damodar River originates here and flows through a
rift valley.
Hazaribagh Plateau The Hazaribagh plateau is often subdivided into two parts – the
higher plateau and the
lower plateau. Here the higher plateau is referred to as Hazaribagh plateau and the lower plateau as Koderma plateau. The Hazaribagh plateau on which
Hazaribagh town is built is about east by west and north by south with an average elevation of . The north-eastern and southern faces are mostly abrupt; but to the west it narrows and descends slowly in the neighbourhood of Simaria and Jabra where it curves to the south and connects with the Ranchi Plateau through Tori pargana. It is generally separated from the Ranchi plateau by the Damodar trough. or as the Chauparan-Koderma-Girighi sub-plateau. The northern face of the Koderma plateau, elevated above the plains of Bihar, has the appearance of a range of hills, but in reality it is the edge of a plateau, from the level of the Gaya plain. Eastward this northern edge forms a well-defined watershed between heads of the tributaries of
Gaya and those of the
Barakar River, which traverses the
Koderma and
Giridih districts in an easterly direction. The slope of this plateau to the east is uniform and gentle and is continued past the river, which bears to the south-east, into the Santhal Parganas and gradually disappears in the lower plains of Bengal. The western boundary of the plateau is formed by the deep bed of the
Lilajan River.The southern boundary consists of the face of the higher plateau, as far as its eastern extremity, where for some distance a low and undistinguished watershed runs eastward to the western spurs of
Parasnath Hills. The drainage to the south of this low line passes by the
Jamunia River to the Damodar.
Manbhum-Singhbhum in
West Bengal In the lowest step of the Chota Nagpur Plateau, the Manbhum area covers the present
Purulia district in
West Bengal, and
Dhanbad district and parts of
Bokaro district in Jharkhand, and the Singhbhum area broadly covers
Kolhan division of Jharkhand. The Manbhum area has a general elevation of about and it consists of undulating land with scattered hills – Baghmundi and Ajodhya range, Panchakot and the hills around Jhalda are the prominent ones. Adjacent
Bankura district of West Bengal has been described as the "connecting link between the plains of Bengal on the east and Chota Nagpur plateau on the west." The same could be said of the
Birbhum district and the
Asansol and
Durgapur subdivisions of
Paschim Bardhaman district. The Singhbhum area contains much more hilly and broken country. The whole of the western part is a mass of hill ranges rising to in the south-west. Jamshedpur sits on an open plateau, above mean sea level, with a higher plateau to the south of it. The eastern part is mostly hilly, though near the borders of West Bengal it flattens out into an alluvial plain. In the Singhbhum area, there are hills alternating with valleys, steep mountains, deep forests on the mountain slopes, and, in the river basins, some stretches of comparatively level or undulating country. The centre of the area consists of an upland plateau enclosed by hill ranges. This strip, extending from the Subarnarekha River on the east to the Angarbira range to the west of Chaibasa, is a very fertile area.
Saranda forest is reputed to have the best Sal forests in Asia. ==Climate==