Fossil Cave (5L81), formerly known as The Green Waterhole, is a

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

in the

Limestone Coast The Limestone Coast is a name used since the early twenty-first century for a South Australian government region located in the south east of South Australia which immediately adjoins the continental coastline and the Victorian border. The ...

region of south-eastern

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

. It is located in the gazetted locality of Tantanoola about north-west of the city of

Mount Gambier Mount Gambier is the second most populated city in South Australia, with an estimated urban population of 33,233 . The city is located on the slopes of Mount Gambier, a volcano in the south east of the state, about south-east of the capital Ad ...

, only a few metres from the

Princes Highway Princes Highway is a major road in Australia, extending from Sydney via Melbourne to Adelaide through the states of New South Wales, Victoria (Australia), Victoria and South Australia. It has a length of (along Highway 1) or via the former ...

(Route B1) between Mount Gambier and Millicent. It is popular with cave divers and is notable for being both a unique paleontological site and the "type locality" for very rare crustaceans (syncarids - Koonunga sp.) which to date have been found only in caves and Blue Lake in the Mount Gambier region.

Description and naming

The cave is formed in 30-million-year-old Oligocene

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...

line

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

. The cave is a

karst Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

sinkhole A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are locally also known as ''vrtače'' and shakeholes, and to openi ...

and is largely filled with water. The surface depression is about long and wide. Beneath the surface it extends to a maximum length of and a width of . The name of the cave was changed on 23 April 1989 by the

Government of South Australia The Government of South Australia, also referred to as the South Australian Government, SA Government or more formally, His Majesty’s Government, is the Australian state democratic administrative authority of South Australia. It is modelled o ...

from ''The Green Waterhole'' to ''Fossil Cave'' with the change being published in

The South Australian Government Gazette ''The South Australian Government Gazette'' is the government gazette of the South Australian Government. The ''South Australian Gazette'' was first printed on 20 June 1839, after the South Australian Government The Government of South Aus ...

on 4 May 1989.

Fossils

Since the mid 1960s, a variety of

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

subfossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

material of birds and mammals has been found and recovered by divers from the surface of a

rockpile Rockpile was a British rock and roll band of the late 1970s and early 1980s, noted for their strong pub rock, rockabilly and power pop influences, and as a foundational influence on new wave. The band consisted of Dave Edmunds (vocals, gui ...

to a depth of about below the water surface. The probable accumulation mode was by animals drowning when they fell into the cave while attempting to use it as a source of drinking water. Dating of the subfossil remains indicated that their deposition occurred mainly between 15,000 and 40,000 years ago. As well as representing many living animals, examples of extinct species recovered from the cave include the birds '' Centropus colossus'' and ''

Orthonyx hypsilophus '' Orthonyx hypsilophus '' is an extinct species of logrunner from the Late Pleistocene of Australia. It was described from submerged subfossil material (an incomplete pelvis) collected in 1979 from the Fossil Cave in the south-east of South A ...

'', and the mammals ''

Thylacinus cynocephalus The thylacine ( , or , also ) (''Thylacinus cynocephalus'') is an extinct carnivorous marsupial that was native to the Australian mainland and the islands of Tasmania and New Guinea. The last known live animal was captured in 1930 in Tasman ...

'', ''

Thylacoleo carnifex ''Thylacoleo'' ("pouch lion") is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the late Pleistocene (2 million to 46 thousand years ago). Some of these marsupial lions were the largest mammalian pred ...

'', ''

Propleopus oscillans ''Propleopus'' is an extinct genus of marsupials. Three species are known: ''P. chillagoensis'' from the Plio-Pleistocene, and ''P. oscillans'' and ''P. wellingtonensis'' from the Pleistocene. In contrast to most other kangaroos, and similar to t ...

'', '' Macropus titan'', ''

Protemnodon anak ''Protemnodon'' is an extinct genus of megafaunal macropodids that existed in Australia, Tasmania, and New Guinea in the Pliocene and Pleistocene. It is also called the giant kangaroo. Taxonomy Recent analysis of mtDNA extracted from fossils i ...

'', and the sthenurine kangaroos '' Procoptodon gilli'', '' Procoptodon maddocki'' and '' Simosthenurus occidentalis''.

Exploration

Fossils were first collected from the cave in 1964 followed by a further collection in 1968 and logged with the

South Australian Museum The South Australian Museum is a natural history museum and research institution in Adelaide, South Australia, founded in 1856 and owned by the Government of South Australia. It occupies a complex of buildings on North Terrace in the cultu ...

. During the next two decades a number of more extensive surveying, sedimentology and bone-recovery operations were carried out by cave divers working in conjunction with palaeontologist Dr Rod Wells and researcher Cate Newton (Flinders University) and the South Australian Underwater Speleological Society (SAUSS) Inc. The cave's submerged extent has been surveyed at least three times including by the Flinders University Underwater Club (FUUC) in 1978, Allum and Garrad in 1979 and SAUSS in 1987.

Recreational diving

Fossil Cave is a notable cave diving site. Access for cave diving is limited to holders of the

Cave Divers Association of Australia The Cave Divers Association of Australia (CDAA) is a cave diving organisation which was formed in September 1973 to represent the interests of recreational scuba divers who dive in water‐filled caves and sinkholes principally in the Lower ...

's Advanced Cave grade.

References

External links