Heritage Places

Heritage Place Details

Map Show Map
Address 13km southeast of Leigh Creek FLINDERS RANGES
Accuracy H - high level confidence
Development Plan Land Not Within a Council Area (Flinders)
Polygon Type D - item has been digitised (generally because it doesn't exist in a DCDB parcel, eg. bridge
Details (Known As) Ajax Mine Fossil Reef (designated place of palaeontological and geological significance)
Registered Name Ajax Mine Fossil Reef (designated place of palaeontological and geological significance)
Significance STATEMENT OF HERITAGE SIGNIFICANCE The former Ajax copper mine is the location of one of the most significant finds of archaeocyath fossils in the world. Archaeocyaths (ancient cups) were some of the earliest known marine sponges with mineral skeletons which lived in the Lower Cambrian period, around 525 million years ago. These organisms proved highly successful, and over a 10 million year period diversified into a huge array of different forms and over 100 species, playing a dominant role in constructing the Earth's first reefs. The large ridge of fossiliferous limestone located at the former mine is known throughout the world as the Ajax Limestone. Remarkably in the context of such finds, the Ajax Limestone contains a sample of almost every archaeocyath species known to have existed within the Australian-Antarctic province, and has a diversity which is far in excess of any other assemblage in the province. In addition to this representativeness, the limestone also contains over 100 type species - species that define a genus. This means that the site is one of the key points of reference for those studying the earliest stages of development for Life on Earth. STATEMENT OF DESIGNATION The Ajax Mine Fossil Reef is a place of exceptional palaeontological and geological significance. It is the only archaeocyathan terrane of its kind in Australia and displays a number of unique qualities. In particular, it is the type locality for the majority of described Australian-Antarctic archaeocyath species and genera. Its significance is enhanced by the fact that it contains so many type species. A type species is selected to represent and define a genus; with the characters of a genus being determined by reference to its type species. Every genus has one, and only one, type species, and Ajax mine has over 40 type species from the Cambrian period, more than anywhere else in the Australian-Antarctic region. This makes it a place with qualities that are both exceptional and irreplaceable, and one which provides a unique insight into the variety and appearance of fauna of the Lower Cambrian period. The Fossil Reef is also of outstanding geological significance, having made a considerable contribution to the history of geological science in Australia including supporting the development of methods for the study of fossils. It is also significant for its contributions to the process of global correlation, including matching the geological record of Cambrian age rocks from all continents, and searching for base metals such as copper, lead and zinc in rocks of this age around the globe. The site has been listed by the Geological Heritage Subcommittee of the SA Division of the Geological Society of Australia (GSA) as a Geological Heritage site (file FR 41).
Subject Index Landscape area - Geological Site; Mining and mineral processing - Mine; Landscape area - Palaeontological Site
Class State
Status Code REG - Confirmed as a State Heritage Place in the SA Heritage Register
Status Date 28-AUG-2014
LGA Unincorporated SA
State Heritage ID 26390
Heritage Number 26985
Section 16 c - it may yield information that will contribute to an understanding of the State's history, including its natural history
As listed in the SA Heritage Register
Plan Parcel & Title Information CL 6186/442 H833900 B693


While due care has been taken to ensure that the SA Heritage Places Database accurately reflects the South Australian Heritage Register and listings of Local Heritage Places in Development Plans, the State of South Australia does not accept liability for the use of the SA Heritage Database for any purpose. Users should consult the Department for Environment and Water - Heritage South Australia to confirm the listing of State Heritage Places and the relevant Development Plan for Local Heritage Places/Contributory Items.

In the majority of cases, the maps of State Heritage Places on this web site show the footprints of the most significant structures on a registered Place. However, sometimes they simply indicate the complete area of land comprising the Place. Work is proceeding to further refine the mapping of such places. It is also important to note that development control is not limited to the registered structures but extends to their setting and structures nearby (what is termed ‘development affecting’ a State Heritage Place). Hence it is vital that exact details of the listed place and implications for any proposed development be discussed with Heritage South Australia staff, as they cannot be deduced solely from the information on this web site. The inclusion of a place in the SA Heritage Register gives no right of public access. Permission to visit properties must be sought from the owners. The accuracy of the mapping of State Heritage Places is not guaranteed. Please contact Heritage SA ( https://www.environment.sa.gov.au/topics/heritage/sa-heritage-register) if you believe there is an error.

GIS files

To access downloadable GIS files, go to Data.SA.