c horizon
C2Formal, Technical
Definition
Meaning
The layer of soil or rock beneath the B horizon, consisting of weathered parent material.
In soil science, the geological substrate from which the upper soil layers have developed, largely unaltered by pedogenic processes.
Linguistics
Semantic Notes
Primarily used in pedology, geology, and environmental science. Often used in contrast to the A (topsoil) and B (subsoil) horizons. Can be referred to as the 'soil parent material' or 'regolith'.
Dialectal Variation
British vs American Usage
Differences
No significant difference in usage between UK and US English in technical contexts.
Connotations
Purely technical term with no cultural connotations.
Frequency
Equally low-frequency outside of technical fields in both variants.
Vocabulary
Collocations
Grammar
Valency Patterns
The [soil] consists of an A horizon, a B horizon, and a C horizon.The [geologist] identified the C horizon as [weathered granite].Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Not used.
Academic
Common in soil science, geology, agriculture, and environmental science papers and textbooks.
Everyday
Virtually never used.
Technical
The primary context of use. Precisely describes a specific soil layer in profiles and surveys.
Examples
By Part of Speech
adjective
British English
- The c-horizon material was sampled.
- They studied the c-horizon composition.
American English
- The C-horizon properties were analyzed.
- A c-horizon sample was taken.
Examples
By CEFR Level
- The soil has different layers, and the deepest one is called the c horizon.
- The soil profile revealed a distinct c horizon consisting of partially weathered shale.
- Pedologists determined that the clay-rich B horizon had developed in situ from the underlying granitic c horizon.
Learning
Memory Aids
Mnemonic
Think of soil layers like a cake: A is the icing (topsoil), B is the sponge (subsoil), C is the plate it sits on (the parent material). C comes last and is the base.
Conceptual Metaphor
SOIL IS A LAYERED STRUCTURE / SOIL FORMATION IS A PROCESS OF DIFFERENTIATION FROM A SOURCE.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating 'horizon' as 'горизонт' in a geographical sense; here it means 'слой' or 'горизонт почвы'.
- Do not confuse with 'C' as in the musical note or the vitamin; it is a technical label for a sequence (A, B, C).
Common Mistakes
- Using 'c horizon' to refer to any deep soil layer.
- Capitalising as 'C Horizon' (lowercase 'c' is standard).
- Pronouncing 'c' as the letter instead of /siː/.
Practice
Quiz
What primarily characterises the C horizon?
FAQ
Frequently Asked Questions
In a strict pedological sense, the C horizon is the unconsolidated parent material from which the true soil (the solum, comprising A and B horizons) develops. It is often included in soil profile descriptions.
Below the C horizon is the R horizon, which is the consolidated bedrock.
Typically, no. It lacks the structure, organic matter, and nutrient availability of the upper horizons. Plant roots rarely penetrate it unless the solum is very shallow.
It follows the standard alphabetic sequence for master soil horizons: O (organic), A (topsoil), E (eluviation), B (subsoil), C (parent material), R (bedrock).