Learn how rocks, minerals, soils and landforms are shaped over time.

What is geodiversity?

'Geodiversity' is the variety of rocks, minerals, soils and landforms, along with the processes that have shaped these features over time. Mountains, caves, beaches, rivers, oceans and even the weather, are all elements of geodiversity.

Geodiversity provides the foundation for life: ecosystems, and the life forms within them, depend on bedrock, soils, landforms and other geological features and processes for their survival. It is also important in understanding the way in which many of the Earth's systems and processes work.

Geological features provide us with places to live, resources for industry, soils from which we grow food, water for consumption, opportunities for healing and places for worship, learning and inspiration.

The Warrumbungles NSW

The Warrumbungles. © Destination NSW

Walls of China, Mungo National Park, NSW

The Walls of China, Mungo National Park. © Destination NSW

Protecting and conserving our geodiversity

Human activities can have an impact on water quality, hydrology, the processes that form and develop soils, and local wind patterns, often resulting in the deterioration or loss of geological features that have formed over millions of years. Often described as relics or fossils, these features (our geodiversity) provide important evidence of past life and atmospheric, hydrological and biological processes.

The protection and conservation of geodiversity is a priority for the NSW Office of Environment and Heritage (OEH) with the majority of the state's significant geological features protected in parks and reserves. OEH also recognises the growing importance of geodiversity to the community and has prepared the NSW National Parks Establishment Plan which identifies the need for greater representativeness of places of geological significance in the park and reserve system.

Other government departments and the community are also responsible for NSW geodiversity. OEH is committed to working with these and other stakeholders on initiatives to conserve geodiversity, including a specific strategy for NSW parks and reserves.

Karst and caves

Crystal formation in Casteret Cave, Jenolan Karts Conservation Reserve © Steven Babka

Crystal formation in Casteret Cave, Jenolan Karst Conservation Reserve © Stephen Babka

What is karst?

'Karst' is a distinct landform shaped largely by the dissolving action of water on carbonate rock such as limestone, dolomite and marble. This process typically occurs over thousands or millions of years, resulting in a variety of surface and below-ground features, including gorges, sinkholes, underground streams and caves.

Karst features interact with the environment to produce complex ecosystems supporting highly specialised plants, animals and micro-organisms. These species contribute to NSW biodiversity and, in many cases, are unable to survive elsewhere.

Caves are integral features

A well-known feature of karst environments is their caves, which typically form in two ways:

  • from surface streams finding their way through cracks in the ground and forming underground rivers
  • by groundwater rising up through cracks in rocks under the influence of heat and pressure, dissolving out mazes and rounded chambers.

Caves provide critical habitat for a variety of plant and animal communities and are nature's time capsules, preserving evidence of past life, climates and earth-forming processes. Caves are highly valued by the community as places for recreation, shelter and refuge and provide water for more than a quarter of the world's population.

Protecting and conserving our karst environments

Karst landforms or environments consist of geological and biological features which are highly sensitive to change. On the surface their thin layers of soil make them highly susceptible to erosion, while below ground, the myriad of solution tubes and water-filled fissures can quickly spread pollution and disease.

Karst conservation reserves, which recognise the sensitivity of karst environments and their special management requirements, have been established at Abercrombie, Borenore, Jenolan and Wombeyan caves. Close to half of the state's remaining cavernous karst environments are protected in national parks or reserves.

NSW karst environments

NSW karst environments are among the oldest and most complex in the world, containing geological features and processes, which indicate their exposure to a vast range of natural processes. The majority of NSW karst environments occur in limestone and can be found in over one hundred separate locations throughout the state.

NSW karst environments are of outstanding national and international importance and are recognised as having one of the most complex processes of cave evolution and development yet demonstrated. Many of these environments contain highly evolved plant and animal species which are unable to survive elsewhere. They may also have special meaning to Aboriginal people as past sources of food and shelter and as places for ceremony.

We are responsible for over 40 karst environments (PDF 446KB), including four karst conservation reserves and 15 sites on World Heritage properties. Some, such as the Jenolan Karst Conservation Reserve, have extensive cave systems which are the focus for tourism and research activities, while others provide critical habitat for migratory bats and other cave-dependent animals.

NSW karst environments were among the earliest protected areas in the world. The Wombeyan Caves were reserved for the purposes of leisure and cave preservation in 1865, followed by the Jenolan Caves in 1866 - both before the declaration of the world's first national park (Yellowstone) in 1872.

Looking from the walking track to the opening of Glory Arch, Yarrangobilly Caves NSW

The Glory Arch, Yarrangobilly Caves. © Garry K Smith

Timor Karst Area

Stand of grass trees, Timor Caves. © Garry K Smith

Karst Management Advisory Committee

The Karst Management Advisory Committee was established to advise the National Parks and Wildlife Advisory Council on matters relating to the conservation and management of NSW karst environments.

The committee consists of the Chief Executive of OEH (or delegate) and nine others appointed by the Minister for the Environment.

The constitution and functions of the committee are in accordance with Section 30 of the National Parks and Wildlife Act 1974.

Karst research

We require accurate, credible and ongoing information to support karst management objectives and better understand the complex interactions between surface and below-ground environments.

The Karst Research Prospectus (PDF 709KB) outlines the framework for conducting karst-related research in parks, and identifies key research themes, relevant planning/regulatory instruments and the functional areas to assist prospective researchers in developing their proposals.

Information to assist landholders

A number of NSW karst environments are on private land. We have produced fact sheets to assist landholders in managing these environments and we provide support. We work with other government agencies, the community and volunteer organisations on a range of karst-related issues.

Visiting NSW karst and caves

Karst environments managed by us contain naturally spectacular caves. Some of these have been developed with pathways and lights, providing visitors with the opportunity to undertake guided or self-guided tours. Other caves provide opportunities for torchlight and adventure tours allowing people to experience them in a more natural way.

Download the complete Guide to NSW Karst and Caves (PDF 8.93MB)

For more information on many of these unique environments and the recreational opportunities they offer, follow the links to individual caves below:

Group tour of Lucas Cave

The Broken Column, Jenolan Karst Conservation Reserve. © Jenolan Caves Reserve Trust

Abseilling at Bungonia State Conservation Area

Abseilling at Bungonia State Conservation Area. © Stephen Babka

More information

Karst environment of NSW poster image

Karst Environments NSW poster available from OEH Information Centre

For further information contact the Karst and Geodiversity Unit on 6332 7680 or

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Page last updated: 30 November 2015