compaction
/kəmˈpæk.ʃən/ (bre, ipa) · /kəmˈpæk.ʃən/ (ame, ipa) · /kəm-ˈpak-shən käm-/ (ame, mw)
compaction — noun
1. the slow geological process where the weight of soil and rock above squeezes loo
the slow geological process where the weight of soil and rock above squeezes loose grains or sediment until they bind together as solid rock.
Mert explained how compaction turns soft seabed mud into shale over millions of years.
collocation: compaction turns [material] into [rock]
The compaction of sand and small shells beneath the lake bed slowly formed limestone.
noun phrase: compaction of [sediment]
Ava studied how compaction in deep ocean trenches changes the shape of buried fossils.
Compaction takes place when layers above press down on softer layers for a very long time.
- lithification
more technical; the full process from loose sediment all the way to rock
- consolidation
broader; can describe any tightening of soil or rock, not only the rock-forming stage
- erosion
the opposite process: rock or sediment being worn away rather than pressed together
文法句型
compaction of [material]
用法筆記
Uncountable noun; typically appears with 'of + sediment/sand/mud' or as the subject of a process verb such as 'occurs', 'takes place', 'turns X into Y'.
常見錯誤
2. the act of pressing something firmly so it takes up less space and becomes dense
the act of pressing something firmly so it takes up less space and becomes denser, often using a machine on soil, snow, waste, or powder.
Amani drove a heavy roller back and forth for soil compaction before laying the new road.
collocation: soil compaction before [construction step]
Proper compaction of the snow at the base camp made it safer to pitch the tents.
noun phrase: compaction of [material]
Caleb checked the compaction of the rubbish in the truck before driving to the dump.
The factory uses high-pressure compaction to turn metal powder into small machine parts.
Padma measured the compaction of the garden soil to see if water could still reach the roots.
- compression
broader; also used for gases and forces, not just packing solids tighter
- packing
more everyday word; usually about fitting things into a container rather than squeezing them denser
- loosening
the opposite action of breaking up dense material to let air or water in
文法句型
compaction of [material]
用法筆記
Distinguish from sense 1: this sense covers a deliberate human or mechanical action over short timescales (minutes to days), whereas sense 1 is a natural geological process over millions of years.