Explanation:

The Koderma plateau is also referred to as the Hazaribagh lower plateau 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, 240 metres (800 ft) 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.