A closely interbedded deposit of sand and mud, generated in environments where current flow varies considerably. The three main types of heterolithic bedding are called flaser, wavy, and lenticular. Flaser bedding is characterized by cross-laminated sands with thin mud drapes over foresets. Wavy bedding consists of rippled sands with continuous mud drapes over the ripples. Lenticular bedding consists of isolated lenses and ripples of sand set in a mud matrix. Heterolithic sediments can be deposited in storm-wave influenced shallow marine environments, river floodplains, tidal flats, or delta-front settings where fluctuating currents or sediment supply permit the deposition of both sand and mud.
Subjects: Earth Sciences and Geography.