The renowned Tank Cave/Green Waterhole complex at Tantanoola has recently been entered into the State Heritage List.
Its inclusion has been justified on many grounds and it contains the only known extensive underwater vertebrate fossil deposits in Australia.
Entry to the extensive underwater world is restricted and is alongside the Princes Highway midway between Millicent and Mount Gambier.
The cave complex has attracted such international figures among the diving fraternity as Thai Cave rescuer Dr Richard (“Harry”) Harris.
It also claimed the life in February 2011 of technical diver, underwater photographer, author, maritime archaeologist and cave explorer Agnes Milowka.
The Environment Department has published a 26 page explanation for the State Heritage listing of the Tank Cave/ Green Waterhole as well as the following summary.
“This unique freshwater depositional environment has ensured the preservation of extinct species not found anywhere else, with several additional species new to science recovered and awaiting description,” stated the departmental summary.
“The underwater deposits have also resulted in a completeness and preservation of fossil assemblies almost unique for Australia.
“This provides an important opportunity to investigate the evolution of South Australian mammals and birds.
“The impacts of this type of site on the age and nature of the fossil remains have yet to be fully studied.
“The Tank Cave/Green Waterhole complex represents unusual geological formations including the occurrence of a shallow fresh waterhole not usually found in sinkholes in the South East, and evidence of rare volcanogenic influences in the formation of the cave system.
“The cave complex also demonstrates rare speleological features, including length of cave passageways, clarity of water, underwater speleothems, and being a type locality for stygofauna.
“The complex also holds importance for the development of cave diving in the country and is closely associated with the Cave Divers Association of Australia.
“It is also acknowledged as a place of significance for the Boandik people.”
