stratum

STRAH-tum ˈstrɑːtəm
nounC1GRETOEFL
formalscientific

A layer or a series of layers of rock in the ground.

Often used in geology to describe distinct layers of sedimentary rock, but can also refer to layers in other contexts (e.g., social strata).

The story behind the word. The word "stratum" comes directly from the Latin word "stratum," which means "something spread or laid down." Think of it as a blanket or a cover laid out flat. In geology, this perfectly describes the distinct layers of rock, often sedimentary, that are laid down over time, one on top of another, forming the Earth's crust.

Word relationships

  • layer: General term for a sheet or thickness.
  • bed: Often used for a specific layer of sedimentary rock.

Commonly confused with

  • sediment: Sediment is the loose material that, when compacted and cemented, eventually forms a stratum of rock.

Word family

  • strata (noun): The plural form of stratum.
  • stratify (verb): To arrange or form in layers.
  • stratification (noun): The arrangement of layers of sedimentary rock.

Collocations

  • rock stratum
  • geological stratum
  • lower stratum
  • upper stratum
  • distinct stratum

Example sentences

  • "Archaeologists carefully excavated each stratum, revealing artifacts from different historical periods." Describing archaeological findings.
  • "The deepest stratum of rock contained fossils of ancient marine life, indicating a prehistoric ocean floor." Geological survey.

Memory hook

'STRAH-tum' sounds like 'straw-tum,' like a stack of straw bales forming distinct layers. Stacked layers

When not to use

While it can mean any layer, in geology it specifically refers to rock layers, not just any random layer of material.

Fun facts

  • The plural of stratum is "strata," which is often used in English.

Related words

geology, fault

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