In geology and geomorphology, a tessellated pavement is a relatively flat rock surface that is subdivided into more or less regular rectangles, blocks approaching rectangles, or irregular or regular polygons by fractures, frequently systematic joints, within the rock. This type of rock pavement bears this name because it is fractured into polygonal blocks that resemble tiles of a mosaic floor, or tessellations.
Branagan recognizes four types of tessellated pavements. They are tessellated pavements formed by jointing; tessellated pavements formed by cooling contraction; tessellations formed by mud cracking and lithification; and tessellated sandstone pavements of uncertain origin.
Now, thanks to Wikipedia you know what a tessellated pavement is (I hope) we can discuss our delightful trip to a fine example of this geological wonder in Tasmania. Alain and Marina, Sinéad’s colleagues been very good to us recently, driving us to Bonorong Wildlife sanctuary the other week and most recently they took us to the Tasman peninsula. If it weren’t for them our exploration of Tasmania would still be very limited indeed, so far that we are eternally grateful!
Our first port of call on the way to Port Arthur was the tessellated pavement, a fascinating geological feature that just begs to be explored. There are two main types of features typical to the this well known feature, mainly the pan and loaf formations.
From Wikipedia: (I know, I know, NEVER use Wikipedia for your sources but I trust it on this occassion).
“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.”
After visiting the tessellated pavement we made our way towards Eaglehawk Neck where visitors can walk along the narrow isthmus of land that was home to packs of ferocious dogs during convict times. You really get a sense of the hopelessness for those wishing to escape the area back in the day, despite the idyllic beach surroundings. From Eaglehawk Neck we made our way further south to the historic site of Port Arthur but I’ll save that for another blog post.