Cross-bedding can form in any environment in which a fluid flows over a bed with mobile material. It is most common in stream deposits (consisting of sand and gravel), tidal areas, and in aeolian dunes.
Where do cross beds form?
Cross bedding forms on a sloping surface such as ripple marks and dunes, and allows us to interpret that the depositional environment was water or wind. Examples of these are ripples, dunes, sand waves, hummocks, bars, and deltas.
Where does graded bedding occur?
Graded beds form when a steep pile of sediment on the sea floor (or lake floor) suddenly slumps into a canyon or off a steep edge. As the sediment falls, water mixes in with it, creating a slurry of sediment and water that flows quickly down a sloping bottom.