Relict mountain
Also called: Residual mountain · Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 11, Ch 2 "Structure and Physiography"
Meaning
A relict mountain (also called a residual mountain) is a very old mountain range that erosion has worn down over a very long time. Rain, rivers and weathering (the slow breaking of rock) remove rock bit by bit for millions of years. In the end, a once-high range is left as low, broken, rounded hills. Relict mountains show how old a landmass is, and they help us tell old ranges apart from young ones.
Example
The Aravalli range runs from Gujarat through Rajasthan to Haryana and Delhi. It is one of the oldest mountain ranges in India and is now a chain of low, broken hills. Other Indian examples are the Nallamala, Javadi, Veliconda and Palkonda ranges, the Mahendragiri hills and the Satpura.
Don't confuse with
- Young fold mountains like the Himalaya are still rising. They are high, with sharp peaks and steep slopes. Relict mountains have stopped rising and are low and rounded.
- Monadnock: a single hard-rock hill still standing on a peneplain (a worn-down, almost flat plain) at the end of the cycle of erosion. A relict mountain is a whole old range worn low, not one leftover hill.