The Cape Range karst consists mainly of three types of limestone. The uppermost, and thinnest layer, the white Trealla Limestone, is mosty dissolved and eroded away. Some significant patches occur on the flanks of the range and it does contain some small caves. It is a hard, crystalline limestone tending to fracture into sharp shards and caves in this limestone are small and difficult.

The layer below is Tulki Limestone. This is the layer that will most interest cavers as it is the main cave-bearing limestone. Again, it is a hard crystalline limestone that shades from white in the uppermost layers to pinkish in the lower regions. It varies from about 50 to 100 metres thick.  The caves in this limestone are mainly vertical shafts, occasionally with crawlway sized and, less occasionally, with walking dimension tunnels leading off for generally short distances. There are a few exceptions to this rule. Wanderers Delight has been surveyed to nearly 7 kilometres length along a multi-level and multi-branching network of crawlway passages.  Chambers of standing height and higher give regular relief to sore necks and knees. Good knee and elbow pads are a must for serious explorers in the Capes caves. Many tiny leads remain to be explored in Wanderers Delight but these are season-dependent due to long-term standing water pools. The remaining leads are many but are also very small and difficult.

Some of the caves require a degree of technical expertise in vertical techniques although many are simple shafts consisting of a single pitch.  Conversely, some of the caves require several pitches to be negotiated and as most of the caves are in the national park, there are virtually no fixed artificial anchors and all caves must be negotiated via temporary rigging, eg tape and cord slings, tricams etc.

The third main layer of limestone is the Mandu Calcarenite. This limestone can be seen in the lower regions of the gorges, particulary along Shothole Canyon, where high exposures of it are easily accessed from the nearby road.  It is a whitish, chalky and relatively soft limestone.

A keen eye will easily spot fossils of shells and echinoids in all the limestones.

In the deeper caves the temperatures are generally up around the 27°-29° C mark. If wearing knee and elbow pads, it is generally more comfortable to explore in shorts and t-shirt. The temperature, coupled with the high humidity, makes the cave environment a taxing, tropical adventure and caving in overalls could potentially assist in causing heat exhaustion. Frequent rest breaks and cool water are recommended on the longer trips. If overalls are preferred then the lightweight version are all that is required.

Many areas of the range have had little visitation and there is always a very good chance that keen walkers will find new, unexplored features. When walking in the ranges, the locals generally wear shorts coupled with sturdy canvas gaiters. Gaiters, useful not only for protection from the fangs of venomous snakes, are wonderful for warding off the spikes of the ever-present spinifex. This spiky grass can be a real torment to tender legs.

The caves are rightly famous for their wonderful and varied array of troglofauna and stygofauna. They can be observed in the deeper caves where the humidity and temperature are fairly constant, and in some of the caves that contain water. Schizomids, millipedes, crickets, spiders, fish, eels, all blind, are commonly spotted during cave visitation.

There are many rock-shelter type caves on the western flank of the Cape Range.  Many of these were used by the Jinigudira, the original indigenous inhabitants.  A cave in Mandu Mandu Gorge returned a date of approximately 34,000 years BP and furnished 22 shell beads and many hundreds of stone artifacts.

The Nullarbor Plain by Dave Gillieson & Andy Spate

This is Australia's largest karst (200,000km2) and perhaps the most intensively studied. The region has an arid to semi-arid climate with annual rainfall between 150 and 250mm, with a winter maximum. Annual evaporation is 1250-2500mm (McKenzie et al., 1987). Relief is low, less than 5m, with slope angles of 1o-3o. The Nullarbor Plain has no surface drainage, but relict stream channels are found on the northern and western flanks of the plain. These have meandering traces and are infilled with alluvium and aeolian deposits. Elsewhere there are aligned depressions with claypans; these are of structural origin (Lowry & Jennings, 1974). These claypans, locally termed "dongas" act to channel the slight runoff and direct it into dolines and blowholes. Dolines are sparse, steep sided and show evidence of collapse into underlying cavities (Photo 3). Blowholes are very numerous, fed by deep solution pipes of complex origin. The caves are extensive, much modified by salt wedging and collapse processes, and commonly descend gently to near-static pools and lakes of brackish to saline water. A low gradient watertable underlies the plain and its depth ranges from 30m in the north to 120m in the south. The flooded tunnels of Cocklebiddy Cave are in excess of four kilometres long - most of it only explorable by scuba diving. Withdrawal of hydrostatic support at times of lower sea level has led to collapse into these watertable caves, allowing entry into large caverns such as Koonalda, Abrakurrie, and Weebubbie Caves (Figure 1).


A particular feature of the Nullarbor caves is the abundance of halite which produces both speleothems and many weathering forms through wedging during recrystallisation. Gypsum speleothems are also abundant with calcite speleothems less obvious largely because of destruction through salt wedging. Speleothem history has much to contribute to the study of past climates and the history of the caves. Lowry and Jennings (1974) provide a good introduction to the geomorphology while more recent detail is given in the review by Gillieson and Spate (1992).

When the long-term operation of karst processes in the arid zone is considered, a fundamental dilemma emerges: are the present features the product of slow, low intensity processes in a variable but essentially arid climate, or do they reflect inheritance from a past, more mesic climate under which processes operated at a faster rate? There is some evidence for wetter conditions on the Nullarbor Plain in the distant past. Firstly, the speleothem sequences mentioned previously. Second, the dark brown to black colours of calcite speleothems which have been demonstrated (Caldwell et al., 1983) to be due to organic compounds such as humic acids, fulvic acids and phenolics, suggesting more effective leaching of soil organic matter. Third, the presence of relict solution tubes and spongework in Thampanna and Old Homestead caves, and the presence of solution scallops in the flooded tunnels of Weebubbie and Cocklebiddy caves (Grodzicki, 1985) suggests a more vigorous fluvial regime in the geological past. Thus the cave systems of the Nullarbor may have originated in a more humid climate phase, and probably span the entire Quaternary. Since the onset of the present arid climate, these features have been heavily modifed by salt wedging and collapse processes (Lowry & Jennings, 1974).

Today exposed outcrops are merely pitted by raindrops, and no solution rills are present. Some solution of limestone does occur in the coastal fringe of the Nullarbor Plain and mixing corrosion may be important in this context (James et al., 1990). The large caves of the Nullarbor may have been initially formed by enhanced solution at the mixing zone of fresh and saline waters (Table 2). The groundwater of the Eucla Basin has a high salinity (Lau et al., 1987; Table 3) and some solution may also be occurring at great depth in the limestone. Inland periodic low-intensity rainfall may cause some solution on the margins of clay pans, and calcretes are forming, but overall rates of solution must be very low. Of more significance are the intrusions of rain depressions of tropical origin which occur twice or thrice per decade. These have the capacity to dump large amounts of water on the western Nullarbor, flooding claypans and dolines, and perhaps maintaining epiphreatic passage forms in several caves such as Thampanna and Old Homestead.


Site Ca++ Mg++ Na+ K+ HCO3- SO4-- Cl- pH
Seawater Standard 400 1272 10560 380 285 2650 18980 8.50
White Lake,
Mullamullang Cave,
317 319 2200 26 57 677 4365 -
Lake Cigalere,
Mullamullang Cave,
326 300 4165 - 33 855 4580 -
Nurina Cave,
891 1052 10440 127 267 3630 17950 7.48
Tantabiddi well,
Cape Range
113 141 999 36 336 240 1810 -
Milyering well,
Cape Range
126 188 1414 53 316 358 2550 -
Pillara spring,
125 &lt0.1 3.1 &lt0.5 318.4 4.5 3.9 -
Baralumla spring,
83.2 1.8 4.3 0.8 198.7 &lt3.0 10.8 -
Windjana bore,
113 0.5 10.9 &lt0.5 272.6 6.3 11.4 -
Table 2: Water analyses from arid and semi-arid karst of Australia (values in ppm).

Type Salinity % of potential yield
Fresh &lt500 mg L-1 TDS 9%
Marginal 500-1500 mg L-1 TDS 56%
Brackish 1500-15000 mg L-1 TDS 31%
Saline &gt15000 mg L-1 TDS 4%
Table 3: Quality of karst groundwater in the Eucla basin (from Lau el al., 1987).


During the last interglacial - glacial cycle the sea level dropped at least twice, steepening hydraulic gradients. This prompted a shift in the isohyets, as reflected in pollen stratigraphy (Martin, 1973). Thus during the last glacial maximum the arid chenopod shrubland of the interior plain extended across terrain which today lies closer to the coast and supports eucalypt woodland. Conversely, during the last interglacial eucalypt woodland would have extended further inland than it does today, and this may have enhanced solutional processes. These changes in the vegetation cover may have acted to destabilise the continental dunefields to the north of the Nullarbor, and allowed reddened quartz sands to accumulate downwind in caves and dolines on the eastern portion of the plain ( Spate et al., 1984). Cave and doline infills on the eastern margin of the Nullarbor are dominantly red aeolian quartz sand with well developed wustenquarz. At least three different pedogenic cycles are involved, with some loessic additions ( Spate et al., 1984). These sands have their origin in the Great Victoria Desert, and suggest a wind regime different to the predominantly southerly to southwesterly airflow today. The distribution of these sands, in a narrow belt around the Diprose Caves, suggests that they may have moved as sand streaks across the gravelly plain. The most recent disturbance of these sands, dated by thermoluminescence at <360 years B.P., may reflect the increased fire frequency consequent on pastoralism and the spread of rabbits across the Nullarbor Plain. Recent environmental impacts on the Nullarbor and other arid karsts are reviewed by Gillieson (1993).

Contact:- David Gillieson, Senior Lecturer, Dept. of Geography & Oceanography, University College, University of New South Wales, Canberra, ACT 2601, Australia. Phone 61 6 2688305 Fax 61 6 2688313 email: This email address is being protected from spambots. You need JavaScript enabled to view it.


A description of the Nullarbor karst by Dave Gillieson and Andy Spate.

A link to some information about the Archaeology of Koonalda Cave

Click here for the Nullarbor Karst Project Outline - 2006-2007

Click here for an April 07 article from the Kalgoorlie Miner about the Nullarbor Project

Audio from a recent interview (15th May 2007) of Paul Hosie (WASG President) with ABC Radio regarding recent work conducted on the Nullarbor. Download Here! Photographs from the January 1997 WASG Nullarbor Expedition Click here for the first Photo page of the WASG 1997 Nullarbor Expedition                             Click here for the second Photo page of the WASG 1997 Nullarbor Expedition The expedition visited a number of the deep caves of the Nullarbor attempting to measure the size of wall scallops at the current water level. Unfortunately this was not possible as there are no wall scallops at water level or just below it to measure :-).

However not all was lost - surface velocity experiments were conducted in the deep caves and the results of this will be correlated with previous work. One of the shallow caves was doubled in length and surveyed. Additionally the survey of Stegamite Cave was completed. Minor extensions were also achieved in a number of other caves.

Assessment of the collapes at both Weebubbie and Pannikin Plain Cave were undertaken with the permission of DOLA and CALM respectively. Reports will be forwarded to the appropriate departments and released here in time.

The expedition also visited a number of the decorated caves of the Nullarbor searching for further examples of stegamites from previously unrecorded sites. The photographic record shows some of the more unusual formations seen.

Expedition members were Rauleigh Webb, John Cugley, Adam Minchin (all WASG members) and Damian Grindley (Chelsea SS & CEGSA). Photographs from the Easter 1997 WASG Nullarbor Expedition Click here for the Photo page of the WASG Easter 1997 Nullarbor Expedition Expedition members were Rauleigh Webb, Veronica Weber and Clive Rippon. Halite Decorations from Nullarbor Caves A number of caves on the Nullarbor Plain contain halite decorations. Here are a few photographs of some of the more delicate halite "flowers" and stalactites. Click here for the Halite Photo page You can also see a few of the pics on The Virtual Cave which also has info on a number of cave formation types. "Coffee and Cream" Deposits from Nullarbor Caves A number of caves on the Nullarbor Plain contain deposits that are known as "Coffee and Cream". These deposits consist of a very dark brown powder adjacent/mixed with a very white powder to create the "Coffee and Cream". The origin of the powders has been determined to result from roof fretting.

Here are a few photographs of some "Coffee and Cream". Click here for the Coffee and Cream Photo page Stegamites from Nullarbor Caves Here are a few photos of a "new" (1991) speleothem from the Nullarbor called Stegamites ( Webb 1991).

Quick characteristics of Stegamites. They look like ridges in floors or a vertical cave shield (They are always vertical.). Only known from the Nullarbor (7 caves to date) and possibly one cave in the Kimberley (Bill Humphreys pers. comms.). All Nullarbor stegamites are in black calite. The black material is as yet unknown. Click here for the Stegamites Photo page You can also see a few of the pics on The Virtual Cave which also has info on a number of cave formation types. Gypsum Speleothems from Nullarbor Caves A number of caves on the Nullarbor Plain contain gypsum speleothems. A gypsum stalactite was first identified by Steve Appleyard on a WASG trip to Kelly Cave. His description was published in The Western Caver in 1983?. Since that time a number of caves have been found that contain large numbers of gypsum speleothems. Here is the first of a number of gypsum photos from the Nullarbor. Click here for the Gypsum Photo page

History. This area extends from the Green Head Road in the south to the Irwin River in the north. The area first received attention from speleologists when W.A.S.G. explored River and Arramall Caves in 1960.

In 1963, Jennings visited the Stockyard Gully caves. On this trip E 1 to E 10 were described and positioned. Of these, Stockyard Bridge, Stockyard Tunnel and Stockyard Cave, together with Aiyennu Cave and Beekeepers Hole were the most significant.

In 1969, D.C. & J.W.J Lowry squeezed through a rockfall in Weelawadji Cave and added 1700 m of passageway to the known 300 m of cave (Lowry 1969). Since this discovery, only the extension of Beekeepers Hole (also known as Uniwa Cave) to 1.4km from 250m has been the major find in this area.

Geomorphology. The limestone of this area is an older aeolian calcarenite than that of the south-west.

The Stockyard System is formed by the Stockyard River which flows almost all of the year. The gorges between Stockyard Bridge and Stockyard Cave are explained by cave roof collapse (Jennings, 1971: 100). The actual cave is prone to flooding as evidenced by the large logs jammed high in the roof and the mud levels above the logs. Classic karst pavements are typified by Aiyennu Cave (Caffyn, 1973) where the calcarenite has collapsed, resulting in soil subsidence, leaving the kankar peppered with solution pipes.

The overflow of Lake Arramall has formed the two major systems of River and Arramall Caves. Arramall Cave contains the largest chambers which are the result of roof collapses. River Cave contains basic phreatic passageways which finally bifurcate and choke off with mud.

The Weelawadji system contains abandoned stream passages of varying dimensions from the 35 m wide entrance chamber to the small 4 m wide phreatic tubes some 500 m into the cave. The whereabouts of the stream which formed the cave is not obvious although it was thought to be part of the Arrowsmith River system.(Lowry, D.C., pers. comm.) Cave minerals collected from the Eneabba area are Brushite and Gypsum from Weelawadji Cave and these samples are held by Government Chemical Laboratories.

Fauna. A large amount of collecting has been done by J.W.J. Lowry in the Eneabba area. She kindly prepared Table 1 which indicates some of the fauna found in Arramall, River, Weelawadji and the Stockyard Gully Caves.

TABLE 1 - Occurrence of selected fauna in the Eneabba Caves (E 1-3) Arramall Cave (E 22) River Cave (E 23)and Weelawadji Cave (E 24)
SpeciesCommon nameE1-3E22E23E24Comments
Baiami volucripes Spider ? x x x Other species occur including one blind species in E22 & E24.
Protochelifera cavernarum Pseudoscorpion x x x x Associated with guano. There are other small species.
Laevophiloscia yalgoonensis Vandel 1973 Wood louse, pill bug, slater x x x x Also tiny blind troglobitic isopods in E22 & E23.
Laevophiloscia unidentata Vandel 1973   x x x x  
Laevophiloscia richardsae Vandel 1973   x x x x There are several other species in all caves.
Scutigeridae (Family) Centipede   x   x E 22 has a species with red legs and yellow spotted body in twilight zone and a blind species (different) in the dark zone (identified as Allothereua lesueurii by WAM staff) (very rare).
Collembola (Class) Springtails x x x x  
Lecanomerus flavocinctus Beetle x x x x Abundantly established in E1-3.
Pseudoceneus sollicitus Beetle x        
Tripectenopus occultatus Britton 1974 Beetle   x     Blind but pigmented. Has not been found alive since 1969 - could be extinct or very rare.
Shawella douglasi Cockroach x     x Reduced eyes and pigment. Unidentified blind species, eyes present but white, in E22 & E23.
Apis mellifera Honey bee x     x E24 - very ferocious (1974, 1978). E1-3 not active 1974.
Litoria moorei Frog   x     Other species in E 3, E 24.
Hirundo neoxena Welcome swallow x x x x Important togloxene at entrances.
Chalinolobus morio Chocolate bat x     x  
Chalinolobus gouldii         x Not known from any other cave sites
Eptisicus pumilus Little bat       x Occasionally seen.
Macroderma gigas Ghost bat   Locally extinct     Many piles of fossil guano in E24 and possibly in E22.