The site has been known for over a century during which it has been extensively excavated to the point of near exhaustion.

The fossil-bearing rocks are fine-grained siltstones and mudstones that are part of the Purlawaugh Formation.

They occur mainly as loose blocks and weathered shales over an area of about 300 by 80 metres (980 by 260 ft), with a thickness of no more than 60 centimetres (24 in).

They are thought to be the remnants of sediments from a small freshwater lake, surrounded by forest, which existed about 160 million years ago when Australia was part of Gondwana.

[2] The fossil material consists principally of the fishes that lived in the lake, as well as plants from the forest, whose remains accumulated in the sediments on the lake bed and were preserved.