Turbidite

Part of speech: noun

Definitions

1. A sedimentary deposit formed by underwater density currents characterized by layers of mixed grain sizes; a geological feature created by the rapid settling of suspended sediments in deep water; a sequence of sediment layers resulting from underwater sediment gravity flows
2. Layers of sediments deposited by underwater turbidity currents involving graded bedding and mixed particles; geological formations created as sediments settle from a turbulent flow in marine environments; distinctive sediment layers formed by the rapid descent of dense sediment-laden water in ocean basins
3. A sedimentary structure produced by rapid underwater sediment flows depositing mixed particles in graded layers; a geological deposit formed by sediment gravity currents carrying suspended materials down continental slopes; stratified sediment sequences laid down by turbulent underwater flows in deep marine settings

Etymology: Geologists needed a name for deposits that look like nothing else in the rock record, and "turbidite" was built from ordinary parts: "turbid", meaning cloudy or muddied, plus the suffix "-ite". That suffix is the same one found in mineral and rock names such as "granite" and "dolomite", which is why the word sounds like a rock. The "-ite" ending passed into English through French, where it had come from Latin "-ītis" and earlier Greek "-ῖτις", a form used to name stones and fossils. The "turbid" part has an older lineage. It goes back to Latin "turbidus", formed from "turba", a crowd or disturbance, and it reached English as a word for water churned up with silt. A turbidite is therefore literally a rock made of sediment stirred into suspension, which then settled out in layers as the flow slowed.

Synonyms: underwater sediment, turbidity current deposit