A tessellated pavement is a rare erosional feature formed in flat sedimentary rock formations lying on some ocean shores. The pavement bears this name because the rock has fractured into polygonal blocks that resemble tiles, or tessellations. The cracks (or joints) were formed when the rock fractured through the action of stress on the Earth's crust and subsequently were modified by sand and wave action.
Sunrise on the tessellated pavement at Eaglehawk Neck, Tasmania, illustrating the pan formation of tessellation
A characteristic example of this formation may be found at Eaglehawk Neck on the Tasman Peninsula of Tasmania. This example consists of two types of formations: a pan formation and a loaf formation.
The pan formation is a series of concave depressions in the rock that typically forms beyond the edge of the seashore. This part of the pavement dries out more at low tide than the portion abutting the seashore, allowing salt crystals to develop further; the surface of the "pans" therefore erodes more quickly than the joints, resulting in increasing concavity.
The loaf formations occur on the parts of the pavement closer to the seashore, which are immersed in water for longer periods of time. These parts of the pavement do not dry out so much, reducing the level of salt crystallisation. Water, carrying abrasive sand, is typically channelled through the joints, causing them to erode faster than the rest of the pavement, leaving loaf-like structures protruding.