A fine-grained sediment rich in organic matter, formed at the bottom of a body of water.
Black, decaying, organic bottom deposits in some lakes, rivers, etc. that lack oxygen and are rich in hydrogen sulfide.
An unconsolidated ooze consisting mainly of putrefied plant remains and found in anaerobic areas at the bottom of swamps, lakes, and shallow seas.
Origin of sapropel
From German Sapropel, corresponding to sapro- + Ancient Greek Ï€Î·Î»ÏŒÏ‚ (pÄ“los, “mud, clay").