1. a sludgy deposit of organic matter formed in oxygen-poor water environments
Usage: geological; technical

Examples

• The lake bottom was covered with a thick layer of sapropel.
• Scientists studied the sapropel to understand ancient climate conditions.
• The dark sapropel indicated low oxygen levels in the prehistoric sea.
• Sapropel deposits can preserve fossils for millions of years.
• The geologist collected samples of sapropel from the marsh.
• Oil formation often begins with sapropel in marine environments.