Chalkie is a remnant of the Tuff layer from a series of past volcanic explosions off the coast.  Before being eroded there were two similar rock stacks on the platform at Swansea Heads. 

 

Biraban, the Awabakal elder who helped the Rev. Threlkheld translate the Awabakal language, explained the legend of their existence to him. He was the major conduit between Thelkeld and the local Aboriginal people. 

​

Although he was never baptized as a Chritian and so not allowed to give evidence in court, he assisted Threlkeld to interpret in court cases involving Aboriginal people and was allowed to speak by some judges.