Surface · Top of a bed, Cross section

Mud cracks (desiccation cracks)

Polygonal cracks on a bedding surface; in cross section, V-shaped cracks filled by the overlying sediment.

How it forms

Wet mud shrinks and cracks as it dries in the air.

Typical setting

Floodplains, playa lakes, tidal flats: anywhere mud is exposed

Way up

Cracks narrow downward to a point (V shape) and are filled from above. Crack edges curl upward.

Flow direction

No.

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