Sedimentary
Describes rock formed by accumulation and lithification of sediments or by chemical/biogenic precipitation at or near the Earth’s surface.
Language and route: English from sediment, via French and Latin. English sediment is from French sédiment and Latin sedimentum, ‘a settling’; sedimentary adds an adjectival ending.
Literal gloss: pertaining to settling
The name and its history
No individual coinage assigned · Geological rock usage attested by 1814
- What does the word literally mean?
- ‘Concerning settling material’, initially associated especially with deposits from water.
- What did the original author mean?
- Early geological writers used sedimentary for substances laid down from suspension, often in an “aqueous” contrast with rocks inferred to have cooled from melts.
- Why was the name needed?
- The terminology helped geologists describe how strata accumulate without treating every kind of rock as an undifferentiated product of a primeval ocean.
- What evidence supported the original concept?
- Bedding, particle sorting, included fossils, depositional contacts and modern sediment accumulation; the original adjective was not a uniquely defined experimental criterion.
- How has geology changed the concept?
- Modern sedimentary rocks encompass clastic, chemical and biochemical deposits, and deposition may involve wind, ice, gravity and water—not water settling alone.
Further historical context
Although sedimentary has an apparently self-explanatory gloss, geological categories expanded beyond the narrow suspended-in-water sense documented in early English.
The precise first geological publication is not established by an etymological attestation date.
Editorial qualification
Keep deposition and lithification distinct; earliest attestation is not proof of first use.
Related names
Sources
- Online Etymology Dictionary, sedimentary — Latin-origin adjective and eighteenth- to nineteenth-century usage
- Charles Lyell (1833), Principles of Geology, vol. 3, chs. XXV–XXVI, full transcript — Contemporaneous evidence for the meaning of metamorphic and the challenge to primitive-rock classification
- International Commission on Stratigraphy, Lithostratigraphic Units — Distinct units based on observable lithology