What is graded bedding?
Graded bedding is a sediment deposit characterized by coarse sediments at its base, which grade upward into progressively finer ones. Graded beds generally represent depositional environments which decrease in transport energy as time passes, but also form during rapid depositional events. They are perhaps best represented in turbidite strata, where they indicate a sudden strong current that deposits heavy, coarse sediments first, with finer ones following as the current weakens. They can also form in terrestrial stream deposits.