Turbidite

A turbidite is the sediment bed deposited by a single turbidity current, a dilute, turbulent flow of suspended sediment that races downslope under gravity. Classic deep-water turbidites show the Bouma sequence, five divisions from base to top: Ta graded sand, Tb parallel lamination, Tc ripple cross-lamination, Td upper parallel lamination, and Te pelagic mud, recording waning flow energy. Each bed marks one event, so stacked turbidites in a deep-sea fan archive the history of margin failures and floods. They are key hydrocarbon reservoirs and a paleoseismic record, since earthquake-triggered turbidites can be dated and correlated along a margin.