Definition

Noun 1. The soil layer beneath the B-horizon and above the bedrock: The C horizon is a soil layer composed primarily of partially weathered or unweathered parent material (rock). It is the deepest of the main soil horizons, lying directly above the solid bedrock (R horizon) and below the subsoil (B horizon). This layer contains little to no organic matter and is minimally affected by soil-forming processes.

Usage Examples

• Noun:
  • The geologist examined the C horizon to determine the parent material of the soil profile.
  • In this region, the C horizon consists largely of weathered granite.
  • Plant roots rarely extend into the C horizon due to its rocky composition.

Advanced Usage

• "Transition to bedrock": The C horizon is often described as a transitional zone between the true soil above and the unweathered rock below.
  • The C horizon showed a gradual transition from fragmented shale to solid bedrock.
• In soil science notation, it is standard to refer to this layer specifically as the C horizon.

Variants and Related Words

• Soil horizons: The collective term for the distinct layers of soil (O, A, E, B, C, R).
• Parent material: The geological material (rock or deposits) from which a soil forms, which the C horizon closely resembles.
• Regolith: A broader term for the layer of loose, heterogeneous material covering solid rock, which includes the C horizon.
• R horizon: The bedrock layer found beneath the C horizon.

Synonyms

• Weathered rock layer
• Parent material layer
• Substratum (in a specific soil science context)

Related Terms (Context-Specific)

• A horizon: The topsoil layer, rich in organic matter.
• B horizon: The subsoil layer, where minerals and clay accumulate.
• Soil profile: A vertical section through all the soil horizons.

Noun

1. beneath the B-horizon and above the bedrock; consisting of weathered rock