# sedimentary rock

CEFR B2 · Noun

Source: https://englishreference.com/word/sedimentary-rock
Updated: 2026-07-28

## Definition

a type of rock that forms when layers of sand, mud, and small stones are pressed together over a very long time.

For teachers: a rock type formed by the accumulation and lithification of mineral or organic particles at the Earth's surface.

## Examples

- Sandstone is a common type of sedimentary rock.
- Scientists study layers of sedimentary rock to see how the local climate has changed over millions of years.
- The preservation of delicate fossils is most common within sedimentary rock formations, where fine silt can quickly cover and entomb organic remains before decay occurs.

## Usage notes

- Uncountable when referring to the material in general; countable when referring to specific geological classifications or types.

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