Residual and transported soils
Topic: Geomorphic Processes: Weathering, Mass Movement, Erosion and Soil Formation · NCERT: Class 11, Ch 5 "Geomorphic Processes"
Meaning
Soils are grouped by where their parent material comes from. Residual soils form in place, from the bedrock weathering right beneath them. Transported soils form from material that rivers, wind or glaciers carried in from elsewhere. A residual soil usually matches the rock below it. A transported soil may have no link to the rock beneath it.
Example
The black soil of the Deccan plateau in Maharashtra is residual: it formed from the basalt below it. The alluvial soil of the Indo-Gangetic plains is transported. Rivers brought it down from the Himalayas.
Don't confuse with
- Weathering mantle: this is the loose layer of broken and rotted rock over bedrock. It becomes soil only after living things add humus and the soil develops layers.
Related concepts
- Soil-forming factors
- Parent material
- Climate as a soil-forming factor
- Eluviation
- Illuviation
- Desilication
- Humus
- Peat