| Fossil Cave | |
|---|---|
| The Green Waterhole, 5L81 | |
  | |
| Location | Princes Highway,Tantanoola, South Australia,Australia |
| Coordinates | 37°43′55″S140°31′52″E / 37.7319°S 140.5310°E /-37.7319; 140.5310[1] |
| Depth | 15 metres (49 feet) |
| Length | 70 metres (230 feet) |
| Geology | Oligocene coralline limestone |
| Entrances | 1 |
| Difficulty | Above water - no stated difficulty Underwater -CDAA Advanced Cave grade[2] |
| Hazards | silting, overhead environment |
| Access | Above water - public (no disabled access). Underwater - CDAA members only. |
| Cave survey | FUUC, 1978 Allum and Garrad, 1979 SAUSS, 1987 Horne, 1986-88[citation needed] |
Fossil Cave (5L81), formerly known asThe Green Waterhole, is acave in theLimestone Coast region of south-easternSouth Australia. It is located in the gazetted locality ofTantanoola[1] about 22 kilometres (14 miles) north-west of the city ofMount Gambier, only a few metres from thePrinces Highway (Route B1) between Mount Gambier andMillicent. It is popular with cave divers and is notable for being both a uniquepaleontological 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.
The cave is formed in 30-million-year-old Oligocenecorallinelimestone. The cave is akarstsinkhole and is largely filled with water. The surface depression is about 20 metres (66 ft) long and 10 metres (33 ft) wide. Beneath the surface it extends to a maximum length of 70 metres (230 ft) and a width of 30 metres (98 ft).[3]
The name of the cave was changed on 23 April 1989 by theGovernment of South Australia fromThe Green Waterhole toFossil Cave with the change being published inThe South Australian Government Gazette on 4 May 1989.[4]
Since the mid-1960s, a variety ofPleistocenesubfossil material of birds and mammals has been found and recovered by divers from the surface of arockpile to a depth of about 15 metres (49 ft) 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 birdsCentropus colossus andOrthonyx hypsilophus,[5] and the mammalsThylacinus cynocephalus,Thylacoleo carnifex,Propleopus oscillans,Macropus titan,Protemnodon anak, and thesthenurine kangaroosProcoptodon gilli,Procoptodon maddocki andSimosthenurus occidentalis.[6]
Fossils were first collected from the cave in 1964 followed by a further collection in 1968 and logged with theSouth Australian Museum. 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.[3][7]
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.[3][8][9][10]
Fossil Cave is a notable cave diving site. Access for cave diving is limited to holders of theCave Divers Association of Australia'sAdvanced Cave grade.[2]
