sedimentary

American  

[sed-uh-men-tuh-ree] / ˌsɛd əˈmɛn tə ri /

Sometimes sedimental

adjective

1. of, relating to, or of the nature of sediment.

2. Geology. formed by the deposition of sediment, as certain rocks.

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sedimentary British  

/ ˌsɛdɪˈmɛntərɪ /

adjective

1. characteristic of, resembling, or containing sediment

2. (of rocks) formed by the accumulation and consolidation of mineral and organic fragments that have been deposited by water, ice, or wind Compare igneous metamorphic

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sedimentary Scientific  

/ sĕd′ə-mĕn′tə-rē /

1. Relating to rocks formed when sediment is deposited and becomes tightly compacted. Depending on the origin of the sediments they contain, sedimentary rocks are classified as clastic sedimentary rocks, chemical sedimentary rocks, or evaporites. Sandstone and conglomerate, for example, consist of fragments of broken preexisting rocks or minerals and are classified as clastic sedimentary rocks. Limestone forms from the precipitation of calcium carbonate through water and is classified as a chemical sedimentary rock. Gypsum and halite deposits form through the evaporation of mineral-rich water and are classified as evaporites.

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Other Word Forms

• unsedimentary
  adjective
• sedimentarily
  adverb
• unsedimentarily
  adverb

Etymology

Origin of sedimentary

First recorded in 1820–30; sediment + -ary

Explanation

Anything sedimentary is formed by or resembles sediment, which consists of little particles of earth that collect in natural bodies of water. If you ever walked in a lake barefoot and felt the grainy, rocky bottom of the lake, you know how sedimentary things feel. Sedimentary is also a type of rock that’s made from substances left from wind, water, or ice and have been pressed together over time. The other types of rock are igneous (made from lava) and metamorphic (changed from intense heat and pressure). Sedimentary things generally hang out at the bottom of lakes and ponds.

Example Sentences

See Examples For:

sedimentary

Even so, their results indicate that the carbon isotope anomaly preserved at Zaonega was driven mainly by events within the local sedimentary basin rather than by a global disturbance.

From Science Daily ● Sep. 26, 2026

The Zaonega Formation was once part of a marine sedimentary basin.

From Science Daily ● Sep. 26, 2026

Workers were digging in a fossil-rich sedimentary rock unit known as the Santiago Formation.

From Los Angeles Times ● Sep. 24, 2026

Its dry climate and sparse vegetation leave fossil-bearing rocks exposed, while its geology contains sedimentary layers of the right age to preserve dinosaur remains.

From Barron's ● Sep. 3, 2026

In the event, the sedimentary layer was 50 percent deeper than expected and the basaltic layer was never found at all.

From "A Short History of Nearly Everything" by Bill Bryson