- one of the most significant Jurrassic terrestrial deposits in the world; and
- the only Jurassic fish site to be found in Australia.
Many of these fossils are on display at Gulgong Pioneers Museum.
During the Jurassic Period (208 -144 million years ago) Australia was part of the supercontinent Gondwana which included Africa, India, South America, and Antarctica. It was a warm and wet world with high rainfall and lush vegetation dominated by Conifers, Ferns and Cycads.
In the Gulgong area 151 million years ago, a freshwater lake existed within a lush conifer forest. The lake contained many plant species and several species of fish, large and small.
Current theory suggests that a volcanic eruption settled ash over the lake killing many plants and animals at the one time. In addition, periodic heavy rain and flooding may have swept tons of volcanic ash from the surrounding area into the lake from time to time resulting in mass deaths. This may explain the layering effect of the fossils over an extended time span.
The large amount of fossilised leaf litter could also indicate periodic flooding because the tree species Agathis jurassica (leaves pictured below) that is believed to have dominated the surrounding forest, shed its leaves in Autumn. These leaves, which comprise the bulk of the fossil plant material, would most likely have been washed into the lake during heavy rain or flooding.
The striking orange, red and brown colouration of the Talbragar fossils is due to the leaching of iron into the fossilised sediments, while the white colour of the plant material is due to the highlighting effects of the contrasting silica.
Source: Gulgong Pioneers Museum
Talbragar fish fossil
Source: Gulgong Pioneers Museum
Talbragar fish fossil
Source: Gulgong Pioneers Museum
Petrified fish embedded in rock, Talbragar fish beds
Source: Gulgong Pioneers Museum
Leaf fossil from Talbragar Fish Beds
Source: Gulgong Pioneers Museum
