Just south of the Lune River in south-west Tasmania, in sediments underlying Jurassic basalt, lie the petrified remains of manfern-like plants – from the Osmundacaulis genus. more...
These fossils are about 180 million years old.
Once upon a time, the area was covered in large trees and ferns – much like most of the region still is today – but it was buried in the ash and lava from a volcanic eruption. The buried trees and ferns were infiltrated by volcanic-heated, silica-rich groundwaters that replaced the plants cell by cell, preserving most of their fine structures. This example of nature’s artwork is best displayed by cutting and polishing the fossil.
The area is world-renowned for these beautiful fossils, which give us a wonderful view into the past landscapes and vegetation of Tasmania. It is also the only known locality where the Jurassic magmas reached the surface to form volcanoes; elsewhere, they crystallised at depth to form the large masses of dolerite that can be seen throughout much of Tasmania.
^ less