North Queensland Naturalist

Natural heritage values of the Chillagoe and Mitchell-Palmer karst and caves

 

David Gillieson

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Abstract                              

Karst (limestone) landforms and associated features such as caves are distributed widely throughout the world. They have many natural heritage values and many are located in protected areas including several which are on the World Heritage List. In North Queensland, two areas notable for their karst geoheritage values have been evaluated as part of the National Heritage List process. The karst towers or bluffs at Chillagoe extend over a considerable distance and achieve heights of up to 65 m above the surrounding undulating terrain. Further north, the karst towers at the Mitchell-Palmer area achieve greater heights and extend over a distance of 80 km between the Mitchell and Palmer rivers. Tower karst is an unusual landscape type in Australia, with clearly the best examples found in the Chillagoe Karst Region. They may be potentially significant at a global level with the closest comparisons being in Cuba and Madagascar. Over 1000 caves have been recorded in the towers, and contain unusual calcite formations, fossil bone deposits and unique copper sinter deposits. A National Heritage List nomination for the Chillagoe and Mitchell-Palmer karst areas was submitted in 2009. The proposed boundaries of the Heritage place were adjusted to avoid current mining leases, reducing the total area by around 50%. The Australian Heritage Council has now assessed the Chillagoe Karst Region and has identified that the Chillagoe Karst Region (including parts of the Mitchell-Palmer Karst Belt) meets the National Heritage criteria for its outstanding karst limestone bluffs, towers and cave development. The Council’s assessment was made available for public review and comment until November 2015, and following this the assessment and comments are now with the Minister for the Environment for a final decision. Current environmental issues include fire management, weed control, feral animals and the impacts of mining.