sedimentary
sed-ih-MEN-tuh-ree
/ˌsed.ɪˈmen.tər.i/
Formed from sediment deposited by water, ice, or wind and then compressed over long periods.
Refers specifically to rocks formed from accumulated layers of organic or mineral particles, often containing fossils.
The story behind the word. Derived from Latin 'sedimentum' (a settling), which traces back to 'sedere' (to sit). Sedimentary rocks are literally formed by particles that 'sit down' and settle at the bottom of bodies of water or land basins.
Word relationships
- stratified: Stratified means layered in general, while sedimentary specifies formation through settling particles.
- igneous: Igneous rock forms from melted magma cooling, whereas sedimentary rock forms from accumulated particles.
Commonly confused with
- metamorphic: Metamorphic rock has been altered by extreme heat and pressure, whereas sedimentary forms from compacted particles.
Word family
- sediment (noun): Matter that settles to the bottom of liquid
- sedimentation (noun): The process of settling or depositing sediment
Collocations
- sedimentary rock
- sedimentary layer
- sedimentary basin
- sedimentary deposit
Example sentences
- "Sandstone and limestone are classic examples of sedimentary rock formed by centuries of accumulated debris." Geology textbook
- "The exposed canyon cliffs revealed distinct sedimentary layers spanning millions of years of Earth history." Canyon exploration
Memory hook
Sedimentary rocks SIT down in layers over time. Settled and layered rock.
When not to use
Do not use to describe volcanic rocks directly formed from cooling magma.
Fun facts
- About 75% of Earth's land surface is covered by sedimentary rocks, even though they make up a small fraction of the total crust volume.
Explore more words
glacier, stratification, sedentary, accretion, collection, precipitation
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