Tessellated pavement
Encyclopedia
A tessellated pavement is a rare erosion
al feature formed in flat sedimentary rock
formations lying on some ocean shores. The pavement bears this name because the rock has fractured into polygon
al blocks that resemble tiles, or tessellation
s. 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.
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.
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
al feature formed in flat sedimentary rock
Sedimentary rock
Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
formations lying on some ocean shores. The pavement bears this name because the rock has fractured into polygon
Polygon
In geometry a polygon is a flat shape consisting of straight lines that are joined to form a closed chain orcircuit.A polygon is traditionally a plane figure that is bounded by a closed path, composed of a finite sequence of straight line segments...
al blocks that resemble tiles, or tessellation
Tessellation
A tessellation or tiling of the plane is a pattern of plane figures that fills the plane with no overlaps and no gaps. One may also speak of tessellations of parts of the plane or of other surfaces. Generalizations to higher dimensions are also possible. Tessellations frequently appeared in the art...
s. The cracks (or joints) were formed when the rock fractured through the action of stress
Stress (physics)
In continuum mechanics, stress is a measure of the internal forces acting within a deformable body. Quantitatively, it is a measure of the average force per unit area of a surface within the body on which internal forces act. These internal forces are a reaction to external forces applied on the body...
on the Earth's crust and subsequently were modified by sand and wave action.
Eaglehawk Neck, Tasmania
Eaglehawk Neck is a narrow isthmus connecting the Tasman Peninsula to mainland Tasmania. At the 2006 census, Eaglehawk Neck had a population of 269....
on the Tasman Peninsula
Tasman Peninsula
Tasman Peninsula is located around by road south-east of Hobart, at the south east corner of Tasmania, Australia.-Description:The Tasman Peninsula lies south and west of Forestier Peninsula, to which it is connected by an isthmus called Eaglehawk Neck...
of Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
. 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.