Some clean but poorly sorted sandstone beds in California contain vertical progressions of thin lens-shaped structures, here termed dish structures. Individuals are 4-50 centimeters long, 1 to a few centimeters thick, oval in plan, and are oriented parallel with bedding. Each dish has a fine-grained, slightly clayey lower surface that is concave-up, and from which clay content decreases and sand size increases upward to a coarse, clay-free top. The size of the structures decreases and the concavity of their bottoms increases higher in the bed. The margins of each dish are truncated by adjacent and overlying dishes, except where they occur along individual horizons with their joined margins forming upward-pointing peaks. Steeply oriented elutriation columns lacking clay an finer sand commonly accompany dish structure. They disrupt or turn up dish surfaces through which they pass, and terminate beneath overlying dishes.

Typical sandstone beds containing dish structure are about 1 meter thick and progress upward from a base of coarse, structureless sand (interval a of Bouma, 1962) through flat lamination, dish structure, and overlying flat lamination (b), to a top of very fine-grained sand containing convolute lamination (c). Dish structure also occurs as a central interval within an otherwise nearly structureless, very thick bed.

Antidunes may produce simple dish structure by alternate scour, and by breaking and deposition in the troughs during aggrading suspension flow in a turbidity current that has declined from dispersion flow (after Bagnold). Middleton (1965) reports structures similar to some dish structures in size and shape resulting from antidune flow. Some characteristics, possibly including clay distribution, may result from sporadic water expulsion, related sediment flowage, and general de-watering of the bed. Dish structure between structureless intervals would require dispersion flow to progress to antidune flow, then revert to dispersion flow.

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