Parent material
Topic: Geomorphic Processes: Weathering, Mass Movement, Erosion and Soil Formation · NCERT: Class 11, Ch 5 "Geomorphic Processes"
Meaning
Parent material is the loose material that a soil develops from. It may be rock weathered in place, or deposits carried in by rivers, wind or ice. It is a passive soil-forming factor: it supplies the raw material but does not drive the process. Its texture, grain size and minerals strongly shape young soils. As a soil matures, climate and living things gradually matter more than the parent rock.
Example
The black (regur) soil of the Deccan plateau in Maharashtra comes from weathered basalt lava rock. This parent rock gives the soil its dark colour and its rich clay.
Don't confuse with
- Bedrock: bedrock is the solid rock below. Parent material is the loose, weathered or transported layer the soil actually forms from.
Related concepts
- Soil-forming factors
- Residual and transported soils
- Climate as a soil-forming factor
- Eluviation
- Illuviation
- Desilication
- Humus
- Peat