Old stage
Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 11, Ch 6 "Landforms and their Evolution"
Meaning
The old stage is the last stage of a river landscape in Davis's cycle of erosion. There are only a few small tributaries, and the slopes are gentle. Rivers meander (loop) freely over vast floodplains. They build natural levees, which are low ridges along the banks, and leave oxbow lakes, which are cut-off loops of the river. The divides between rivers are broad and flat, with lakes, and the land lies close to sea level. The stage ends in a peneplain.
Example
The Burhi Gandak near Muzaffarpur in Bihar winds over a flat floodplain and has left oxbow lakes. These are typical old-stage features.
Don't confuse with
- Mature stage: valleys are still deep and V-shaped and the divides are sharp. Floodplains and meanders are only beginning to widen.
Related concepts
- Landform
- Cycle of erosion
- Youth stage
- Mature stage
- Peneplain
- Monadnock
- Sheet erosion
- Lateral and vertical erosion