strata
STRAH-tuh
/ˈstrɑː.tə/
Layers of rock, soil, or material stacked one upon another; also social classes or levels.
Plural of 'stratum'. Refers to horizontal beds of sediment or rock representing distinct historical time periods.
The story behind the word. From Latin 'stratum', the neuter past participle of 'sternere' (to spread out or lay flat). The same root gives us 'street' (a paved, laid-out road). In geology, strata are literally sheets of rock spread out flat over the earth.
Word relationships
- layers: Layers is a general word; strata specifically implies formal, stacked horizontal geological or social levels.
- beds: Beds is informal field terminology for individual sedimentary rock layers.
- uniformity: Uniformity implies a homogeneous mass without distinct layering.
Commonly confused with
- stratum: Stratum is the singular form (one layer); strata is the plural form (multiple layers).
Word family
- stratum (noun): A single layer (singular of strata)
- stratify (verb): To form or arrange into layers
- stratification (noun): The geological process of forming layers
Collocations
- rock strata
- geological strata
- sedimentary strata
- social strata
Example sentences
- "The exposed cliff faces revealed distinct strata of red sandstone and grey limestone stacked neatly." Geological field survey
- "Geologists analyze rock strata to construct precise timelines of ancient climate change across epochs." Climate research
Memory hook
STRATA are SPREAD out flat like carpets in a stack. Spread-out rock layers.
When not to use
Use stratum when referring strictly to a single individual layer.
Fun facts
- The principle of original horizontality states that rock strata always form horizontally due to gravity; any tilt means later tectonic forces pushed them.
Related words
Explore more words
stratification, mobility, shear, stratosphere, epoch, excavate
Take your vocabulary further with LangBlitz
Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.