Wellington is in central NSW about 5-6 hours drive from Sydney. There are two main tourist caves (Cathedral Cave and Gaden Cave), many small caves and a phosphate mine started in 1910 in what was to be a hopeless search for agricultural phosphate.
Wellington has a long, illustrious and infamous fossil history. The first diprotodon bones were discovered at Wellington. A diprotodon is an elephant-sized marsupial that roamed Australia until about 10,000 years ago. "Diprotodon" means two front teeth. The skulls may be the size of an elephant's, with two prominent teeth protruding forwards from the upper and lower jaw. It is commonly believed that Australia's changing climate destroyed this animal, but the glacial periods in Australia were dry, not wet. Conditions for the diprotodon would have been improving rather than the reverse.
A feature of the diprotodon skull is its small cranial capacity. Its brain was small and it would be a reasonable to conclude that this huge marsupial was not intelligent. Its size would have protected it from most predators and intelligence would have been an unnecessary asset for its survival. However, one devastating predator may have been responsible for wiping out this largest of the marsupials. For the aborigines the diprotodon would have been an easy target since it would have not adequately responded to attack from sophisticated weapons such as spears and clubs and herding tactics. There is only meagre evidence that the aborigines hunted diprotodons, such as an alleged arrow head like stone found in a diprotodon bone, and sites where bones are layed out as if in the butchering position. Although no such dramatic evidence as this was found at Wellington the Wellington diprotodon fossils were the first to be found in Australia.
By the light of torches and fires, the first large bones were found in the Bone Cave in 1830. Surveyor General Michelle and Rankine descended the Bone Cave and removed bone deposits. These were sent to scientists in Paris. Baron Curvier and William Pentland examined them and identified the large bones as that of a small elephant.
Wellington has a strong history of rain associated with its considerable fossil deposition. In places the unassociated bones are aligned in the same direction although mostly the fossils are fragments or the ends of bones sticking out from the wall of the cave and all jumbled in turbulence. How can all the fossils have been concentrated in one place? Many different sizes of bones from animals of all kinds have been collected together and then dumped in this one place. Possibly animals died and collected in the many cave entrances and shafts in the area and then later a flood washed through the caves and moved the bones to where they are now.
The removal of fossils from Wellington characterised paleontological science at Wellington for more than a century. Diprotodon bones found during the excavation of the phosphate mine were immediately packed in cases and sent overseas. In the Eric Gardell collection there are photographs of guides sitting on a verandah heaving large hip bones into hessian sacks. Some of the major collections were shipped to Munich in Germany. The prospect of ever retrieving these fossils may be found in the debris of the bombings during World War II. The treasure of bone deposits is gone but there remains the possibility of finding a cave undisturbed with the same richness of fossil deposits.
My first visit to Wellington was to go diving with Simon McCartney and his wife Judy. They had been asked by Mr Ernie Holland (Jenolan Caves Reserve Trust) to dive in an uninviting little hole in a cave called Limekiln. The plan was to find a lost lake cave buried somewhere beneath the caravan park by diving in the hole at the bottom of Limekiln and swimming through into the lost lake. The lost lake was in a cave buried in order to construct a nice flat caravan park. All the holes and caves in the park area were filled with rubbish and buried with rubble. Anticline Cave had once been a tourist cave reported to contain a gate with steps that led down to a lake.
As is the way with many such lost lake caves, the folklore and stories abound. The bane of any historian is separating the romantic tales from the possible leads. In Wellington it couldn't be any worse since the locals seem to love a good story. I have been told about a photograph of this lake that shows a jetty leading into the water with people paddling a canoe round on the lake. Although this picture has never actually been seen by anyone I know many people do have friends that have seen it. A local story recalls that 100 cases of whisky were stolen from the local golf club about the time that the cave was covered over. The whisky is said to have been hidden in the cave.
In the bottom of Limekiln Cave is a small drain hole with a pool of water, deep and limestone blue. Blast shatter marks surrounding a drill hole record its speleogenisis, perhaps brought about by the phosphate miners many years ago. Simon and Judy had already dived once in this place. It was a brave effort to be the first in that tiny hole. The room with the birth hole is about the size of a telephone booth at the very bottom of the cave. The birth hole is too small to pass through with tanks, so they descended into the hole with a regulator in their mouth dragging the tanks down on top of them and put the gear on under the water. Although the squeeze is intimidating, once in the chamber below the cave widens dramatically.
On my first trip, we brought my video camera intending to record the new find to show Ernie what was down that horrible little hole. The entry had been streamlined by using a hookah hose but now it was complicated by cameras and lights. Greg Wilkins had been trying to build underwater video lights. Every time we had taken them diving they leaked but they were getting more reliable and so my first dive in McCavity was to be experienced through the eyepiece of a video and lit by 400 watts of light. I was so busy trying to frame pictures correctly and get into a good position that I was not to know that Simon and Judy were heading off in a completely new direction and that the cave became large and very long. They tied off the guideline and reeled out down a tunnel filed to the roof with water about 10m deep and 15m across at the bottom. The tunnel was decorated with huge stalagmites, pendant draperies, flowstones and helictites. At times we surfaced in small air chambers but we could instantly tell from the taste of the air that it was high in CO2 and unbreathable. The surfaces in these chambers were clothed in floating calcite rafts. As our bubbles burst to the surface and the tension of their silent existence was laid to rest. They rained down through the water like snow. Some of the larger rafts would slice left and right through the water like a falling leaf. The floor of the cavern was in places metres deep in these calcite flakes.
I only realised that this wonderland was new territory after returning and extruding myself through the entrance squeeze into the small telephone booth room above. I started to suspect something had happened from the chortles and squawks by Judy and Simon who were considerably chuffed about the whole experience. The video wasn't very good because there wasn't enough light. McCavity Cave didn't connect to Anticline but it is most significant. The cave is adorned with spectacular formations, which is unusual because underwater caves do not normally have formations...they tend to dissolve.
The Wellington caves have been visited by SUSS since 1950 on a semi-regular basis. During these early years not many university students owned cars and many of the caving areas that were visited were close to railway lines. Molong and Wellington, both on the western line to Dubbo were visited often, and although student mobility permitted visits to other areas, Wellington continued to attract visits. In the 1980s the water levels in the caves fell dramatically because of a severe drought . The water level in McCavity was down 4-5m. Armstrong Osborne, Bruce Stewart and Tony Allen were able to climb down to the water through the narrow blast hole using a caving ladder. At this time there was a lake which they explored riding on the back of air mattresses. Based on the map they produced we are now able to conclude that they narrowly missed discovering the Long Tunnel and the huge chamber beyond. If they had they ducked under the lip with a mask and snorkel they could have entered Long Tunnel and most likely died from the CO2 that we now know accumulates there. The drought passed and McCavity returned to a diver-only domain.
The position of the lost cave in the caravan park was known from surveys done by Oliver Trickett, defined in relation to a well that can still be located in one of the paddocks behind the hotel units. There was just a little doubt because there are several wells. On one weekend the council provided a digger and a spectacular excavation commenced in the caravan park. Local television news teams set up their impressive betacams and sound equipment, so the event was nearly a circus. As our hole in the caravan park hole grew deeper and wider a septic overflow pipe was exposed, then the main wiring for the power, and then the putrid discharges of forty years provided a rustic odour to the whole proceedings. A very impressive cave dig, we all thought, but just a trifle embarrassing since no cave could be found. There were some older people present that claimed to have been here at the time that the cave had been filled. They would look knowingly and declare that it was more likely to be over there...under the swimming pool. They could remember it clearly. We returned to Sydney that weekend without finding the lost Lake Cave.
It is a long journey back to Sydney after each weekend. The rolling hills of country are tinted orange by the glow of sunset. As the night takes hold the air can at time get perishingly cold but with the car heater turned on we are snug against the chill outside. There was a sudden crash against the underside of the car and we stopped to check what had happened. There was no damage to the car and everything underneath seemed fine. We continued on into the night and everything was fine until we slowed down entering Orange. The water temperature soared and the radiator boiled. I stopped in the first garage, optimistically filled with petrol and looked under the hood. Under the hood the problem could be seen. The generator had fallen out...it was gone. No generator, no fan belt and nothing to drive the water pump and keep the engine cool. Greg looked out of the windscreen with a hopeful smile knowing that we could improve a solution to anything. This is a difficult item to improvise, I thought. I filled the radiator with water, closed the hood and said we have to drive at 120kph all the way back to Sydney. It was so cold outside that the rush of air over the engine was enough to cool the engine without the need for a water pump. We set off at a great speed but soon stopped again with the realisation that the battery would not last to run the headlights long enough to get very far. Greg stepped outside and used duct tape to stick the diving lights to the roof. They were too powerful and would blind oncoming cars. We were able to switch the dive lights off and change to normal and back again once the cars had passed. Normally the dive lights have to be cooled under water but what was good enough to substitute for a water pump could cool the lights as well. I slowed down a bit through Bathurst and the temperature shot up. Once out of Bathurst we were able to bring the temperature right down again and even make the hill at Victoria Pass. As we approached Katoomba any attempt to change over to headlights would kill the engine but the dive lights were losing it also. At Katoomba we gave it away. Greg went home on the train and I slept outside an auto-electricians.
The Wellington Shire Council surveyor was sent to check the survey work. Naturally his survey agreed with ours. The long-armed digger was brought in again and the hole dug deeper and wider. This time a cave was exposed. Four meters down and over a bit the fabled entrance was revealed and inside there was the lake. Not quite as big as we imagined and there was no sign of the canoe. The fill covering the cave entrance was composed of a great deal of rubbish and a lot of it was running down into the water. In the past, Anticline Cave was used as a tourist attraction. How sad it is now. A set of steps lead down to the edge of the water. Many of the steps are buried by infill and the original tourist entrance under several meters of compressed rubbish. There were many hundreds of empty bottles some of which were whisky bottles but their contents had been consumed. I dived the lake with Simon and it is just a blind lake. I dived it a couple of time later to make sure it didn't go...though, you never know for sure.
The earth surrounding the cave entrance is a collage of rubbish which spills down the steep slope into the cave entrance and into the water. The debris is mostly composed of earth fill with the top metre made of compacted rocks. The rubbish consists of sheet tin, fencing wire, pipes, tin cans, broken glass, bottles, dry cell batteries and rocks. This contamination is of particular concern because the local water supply is taken from a well 150m away from the cave entrance. The rubbish may contain items of historical interest such as the old gate which closed the entrance when used as a tourist cave. The urgent need to remove the material filling the doline and the need to conserve any such artefacts are in conflict but in my mind the water should be cleaned up.
The infill material surrounding the entrance doline is falling into the cave entrance as a result of rainwater erosion and the decomposition of the rubbish upon which the land fill was deposited. The north side of the doline has eroded up to the edge of the fence with two of the concrete footings of the fenceposts partly exposed. The south west corner is the site where most of the rubbish was placed and also the site of the original cave entrance gate. The compressed rock covering the rubbish extends south and west, under the present fence into site 9 and also west under the present road. The interior of the cave slopes down over a conical mound that is in part made up of natural and recent depositions. It may block further extensions to the south on the east and west edges.
At times the cave interior traps dangerous levels of carbon dioxide. Local anecdotes report that rabbits venture into the mouth and lose consciousness. Apparently if you capture a rabbit (easy when its unconscious) it recovers when removed from the cave. There are not any rabbit bodies collecting inside and therefore an occasional whiff of fresh air must revive the unconscious rabbits that may then escape with tall tales of strange rabbit dreams.
The immediately important goal is to remove the large body of polluting material located in the doline. The doline is at present regarded as a curiosity in the caravan park, but in the future may serve as an additional natural feature to attract visitors to the Wellington Caves Reserve. The cave is not large enough to charge visitors for a tour but may be developed as a self guided tour that will act as an advertisement attracting more people to visit the park. The cave might also be included as one of the stops of importance in other educational tours run by the Reserve. It has an excellent anticline in the roof, although it should be said that there are also some excellent examples of folding in Cathedral Cave.
Appropriate landscaping will restore a more natural appearance to the doline and reduce steep land fill edges presently contributing to erosion and possible collapse. Widening the doline mouth and the entrance to the cave will help to circulate and flush the air inside the cave and vent carbon dioxide to the outside. This will also be helped by exposing the old tourist entrance in the SW end of the doline. Lengthening the perimeter of the doline will provide a more gentle slope into the cave reducing erosion allowing the exposure of a natural limestone rock landform and then blended into the grassed areas of the caravan park. We dived in Anticline but the lake appears to be shallow and silted up with very uninviting leads. There is a strong possibility that there is more cave to find once all the rubbish is removed from the pit.
Cave diving in NSW goes back to sump exploration in the early 1950s at Jenolan, Wombeyan and also Wellington. SUSS and SSS explored the sumps in the major caving areas and shared the same learning history of cave divers around the world but fortunately without accident if not without a share of "learning experiences". We hope to continue this illustrious history. A significant component of the achievements of NSW cave diving has been because of its growth alongside and in co-operation with the cavers. The caving techniques and understanding/feel of the caves was I believe the factor of success in the early discoveries in the sumps at Wombeyan and Jenolan. Jenolan is a series of major discoveries yet to happen. The exploration of Wellington is only just in play. My opinion is that another submerged cave like McCavity is in the hill at Wellington and we are going to find it.
Several years ago, SUSS placed a project-based management plan
for McCavity before the council. It asserted that McCavity was
a scientific site of national importance and that there should
be only project-based diving done in the cave. With no impact
assessment of diving there is no way to estimate what frequency
of diving would be protect the cave. We set a maximum trip frequency
of one trip per month and would adjust this if there seemed to
be adverse effects. This was an intuitive (ad hoc?) assessment
but I still feel this guess is about right. The project proposal
specified a series of ambitious project goals to promote science,
tourism and education. It suggested a photographic summary of
the cave and its features that would contribute to a feature in
Australian Geographic, sampling and analysis of the water chemistry,
a survey of the biology within the cave, a survey of the cave
and a documentation of features in the cave in relation to the
survey, a map and further exploration.
Greg Ryan, Greg Wilkins and Merv have been the backbone surveyors. At first Greg R and I surveyed using topofil and compass but felt the accuracy with a dive compass was not going to be accurate enough. We built a few different survey devices finalising on a design whereby two rectangular pieces of perspex were hinged together. The top piece had two alignment knotches and the lower had a circular protractor mounted on the lower hinge so that it could rotate. A compass was fixed onto the protractor. A bearing could be taken by aligning the knotches on the top hinged plate with a fine dive line stretched between two survey stations. The protractor would be rotated until the compass pointed north and then a bearing read from the protractor. Everything was made of transparent perspex so that the compass could be seen from any direction even underneath through the device itself. Once the device is aligned on the guide-line and the compass aligned to north the device could be removed from the line and the bearing read at leisure. The surveying went slowly and there is still work to do but we have put together a good map in the meantime. We were getting to know McCavity quite well with the survey many of the little details were being filled in. The general layout and of the cave is now a known quantity. There is not likely to be a huge extension to be found now but you never know for sure.
At the beginning of the project we booked permits for a trip once a month. A core group of project members have become synonymous with project and our goals were channelled towards achieving what was on our proposal list. At the top of the list was photography. The spinoffs from good photographs would promote Wellington Caves as a tourist attraction and also promote cave diving as an activity that when treated with respect can be safe. Photographs of formations in the cave might show fossils and formations of scientific interest.
Mark Spencer is one of Australia's foremost photographers. He is by profession a dentist but during the course of the project gave up his practice in order to become a full time photographer. I first took Mark into McCavity on a dive for him to assess its potential as a project site for his photography. On this first dive we entered one of the air-filled chambers we called the Hanging Swamp. Some of the chambers in this cave are polluted with high concentrations of CO2 but in this chamber the air is breathable. I took the opportunity to show Mark why caving is so much fun and shed my dive gear to go exploring. Mark floated on his back in a safe area while I shinnied up a rift into the ceiling and rained rocks out of the ceiling from great heights. On this trip I found the Beach Chambers and the minor arm of the Hanging Swamp were connected, and that there were a few rift passages and a complicated rockpile above the lakes. Since that time we have never re-found this rockpile. I returned to Mark still in the water, cursing himself for not bringing a camera but absolutely wrapped in the notion of making McCavity a photographic project.
The problem of joining Mark on a photography trip is accompanying his vast array of photographic equipment. The joys of transporting diving paraphernalia are multiplied by the camera boxes and inversely multiplied by the frailty of the lenses. There is nothing quite so humorous as putting a few light bulbs in a plastic bag and packing them in a vulnerable place waiting for the inevitable. We try to "containerise" everything into cave packs and we are also starting to use tank packs as well. Tank packs help protect the tanks, help keep dirt and mud out of the valve stem and also protect the cave. The last person in the water has their gear transported to the telephone box first, and so on. The gear is stacked in a small alcove accessible in the order of each diver's entry into the water. We have a maximum of four divers in the water at a time to avoid congestion at the narrow entry point and there is a helper standing by in the telephone box at all times during the dive. The squeeze requires that the diver descends into the water without scuba gear, reaches back through the hole to get the gear and then puts the tanks on under the water. We usually use a regulator on a long hose for the diver to change into their gear but now the water level is low there is enough air below the hole to gear up in an air bell. We also station a spare air bottle just off to one side.
Mark set up a camera on a tripod in the main chamber. The main chamber is big: "It's so big that the light just falls into it." A high wattage flash is swallowed by the darkness. Mark would spend the first half of the dive transporting his bulbous cameras with their crane-like flash extensions into the middle of the great chamber. He also brought two long plastic pipes that he slid over the legs of the tripod. The unit was placed on the silted floor with its extra long stalks pushed into the sediment to keep the camera nice and firm. Mark's companion/safety diver would station him/herself behind the camera and spend the next 45 minutes floating in weightless sensory darkness while Mark finned about in the chamber to a set of pre-determined locations. Here he would blow off the flash and expose a tiny portion of the cave, then proceed to another area and do it again, in this way building up the exposure of the great cavern on the film. He navigated in the darkness with his compass. A fluorescent green chemical stick was placed behind the camera which also gave some frame of reference. For simple tasks like adjusting flash settings, writing notes or not banging into sharp stals he use a pencil sized red light. Water absorbs red light before the other colours so it was thought that the red light would be absorbed be the water and be unlikely to reach the camera. It wasn't and it did. The first photograph contained red lines tracking Mark's 'invisible' route through the cave. It would be necessary to do this several times to get it right. Each photograph consumed the efforts of the entire dive and he would get two on a weekend. The next attempt looked better but the photograph had unexposed regions and the multiple flashes gave the pictures a patchy look. He would have to try again.
Mark began using hip mounts. These are tanks that are mounted at the hip rather than worn on your back. The advantage is that they may be attached and detached while in the water. After making an exposure he would return to the small entrance hole, slide both tanks off and replace them with fresh ones. His dive time increased and he was able to get two pictures in a day, four in a weekend. By the end of the dive he would be very waterlogged and tired but would still put in a cheerful face at the traditional Saturday night barbeques.
The fossil record at Wellington spans about 100,000 years before the present, a period known for gigantism in the fauna. Fossils found in this period include two metre high predatory birds, very large snakes capable of crushing a dog, giant kangaroos, goannas up to 15 metres long and a fierce some marsupial lion. McCavity has only been entered by divers and the possibility of such fossils being found is ever present but only if such fossils could be seen on the floor. Although there are places with the floor stacked with small bones it is unlikely that we will ever dig in these locations.
Neil Vincent was keen to photograph the fossil skeletons exposed in the mud just inside the big cavern. He and his wife Lynne hovered above the silt worrying about F-stops, flash ratios and photographer type stuff when they noticed a funny little white scuttly thing running about in the skull and attempting to hide under one of the calcite raft deposits. Neil had been placing mop traps in the water to trap small animals. After a month the mop was placed in an esky along with a matrix of tree roots where animal often like to make their homes and sent to Wolfgang Zeigler at the South Australian Museum. Wolfgang wrote back to us. He was quite excited about the various animals we sent him. He report ed that he couldn't resist taking a quick peek when they first arrived and ended up sorting through the lot. He had found Ostracods (small bivalves), Copepods (plankton-like), Isopods (flattened crustaceans) and Amphipods (like beach hoppers). He said that he found the Asellota isopod among the tree roots but not in the mop trap. Apparently the isopod is rare in Australia although he had collected them before from springs in the Great Australian Divide. Most likely they are an undescribed species but he said "Please send more samples." Wolfgang was particularly interested in the white scuttly thing that Neil and Lynne had spotted: "It might possibly be a syncarid, and that would be very exciting." The team was a bit bemused by all this biology stuff but the treasure hunt was on - "Get that syncarid!".
Neil's photograph of the skull didn't look like it was underwater at all. He needed to throw up a little cloud of silt for such photos to give that underwater look. The red brown floor on which the skull sits is a matrix of small bones with the skull clearly displaying canine teeth. We thought that we may have found a thylacine. This would have been something since it is thought that the thylacine became extinct on the mainland about 5000 years ago. That would have meant the exposed fossils in McCavity were quite old. At the time of the syncarid hunt I was attending a continuing education course at Sydney Uni about fossils. Michael Archer is an enthusiastic palaeontologist at the University of New South Wales who lectured part of the course. Michael was enthusiastic about the photo and felt sure our skull was a thylacine but he would need one of the jaw bones to be sure. I was unenthusiastic about removing a jaw bone. The history of Wellington records the continuous practice of scientists removing fossils. I was not keen to go on removing bones from their native sites. Australian Geographic was keen to publish an account of a thylacine discovery. There was no choice, we had to be sure in case made fools of ourselves. We fronted the jaw bone to UNSW whereupon it was identified as belonging to an Eastern Quoll. The Quoll is believed to be extinct on the mainland with the last sighting reported in Neilson Park in Sydney. Its niche in the environment is possibly now occupied by the cat. Oh well!
On the next trip, Rob Featonby and Merv captured a syncarid near one of the skulls. They emerged from the cave and placed their prize in a lens cap, where it was photographed to death. We needed to send it to the South Australian Museum but we didn't have any formalin to preserve the specimen. Someone suggested using metho. Clearly if metho was any good, people would use metho rather than formalin...therefore it can't be any good. Neil, fast on the draw, withdrew his cellular phone and rang the SA museum. "NO" they said, "metho is no-good, use formalin!" On a Sunday, where do you think it is possible to get formalin? The lads drove to Wellington Hospital where the nurses were extremely helpful and managed to find a bottle for us. Just before she handed it over she asked "What do you want it for?"
Wolfgang wrote back, "The two creatures are syncarids and both are female and this is the second record of a syncarid from caves." As it turned out Stefan Eberhardt was doing a survey of cave organisms for National Parks. He had found syncarids in other caves, including Jenolan. The next time we visited Wellington, Stefan was there, ready to dive and ready to catch syncarids. He found that syncarids were everywhere and there were multiple species and you didn't have to dive for them - you could collect them from the surface. A couple of weeks later an article appeared in the Sun Herald about how National Parks had discovered syncarids at Wellington. You can't believe a word you read in the newspapers.
The entrance to McCavity, the dolines outside Cathedral Cave and the holes behind the kiosk seem to be ancient stream sinks. It would seem likely that the caves are connected and once formed a drainage system. With the Jenolan model it is so easy to see some of the formation forces at work. The erosion and cutting of pressure tubes, keyholes, vadose canyons and phreatic passages with telltale sign of immense water flow. Alas, the curse (and blessing) of nature is its intricacy. Many caves do not form in this way. Mt Etna, Yessabah, the Nullarbor are all caves with a different mechanism of formation and not necessarily similar to each other. Rather than formation by erosion, Wellington may have chemically "dissolved". Each water body may be a sealed pond and that the swallet entrances are rain run off collectors rather than stream inflow entrances. Each volume dissolved away along joints or points of chemical interaction. The Long Tunnel in McCavity initially seemed to be a river passage, except that the large passage suddenly stops and turns to the left abruptly at an intersecting joint passage. There is no sign of down cutting, or vadose canyons and phreatic sections show very little evidence of scalloping, although some in the entrances. The northern end of Long Tunnel seems at first to be the edge of a chamber but is actually a set of northern trending rift passages that continue through rock pile and breakdown and are in places interconnected. From these rifts, silt and debris enters perhaps from the collapse or possibly conduits to the surface. Outside the entrance of McCavity there are two significant dolines, one with a very good collapse in it. It is possible that these dolines were filled when the phosphate mine road was put in. Possibly a lot of the inflowing debris is recent. My opinion is that the water level has been raised by the phosphate mining activity.
The formations would have taken a great deal of time to form. In McCavity, all the formations (which are spectacular) are in the roof. It is reasonable to conclude that the water level of McCavity is naturally lower than at present and judging from the formations about half way down the cave. Mud in the floor has hexagonal cracks in it so we know that at times the cave dries out completely and that when it refills the water flow is not turbulent enough to disturb the cracks. The water level in McCavity falls very slowly at a constant rate.
Each month we measured the height of the water. We started doing this so as to calibrate the depth measurements that we take for the surveying. As we survey the cave it is not necessary to measure the inclination angle between survey stations, instead we take a reading with our depth gauges. Since the water level changes each month we need to adjust each depth reading by a reference depth measured always at the same station next to the entrance. Out of interest we graphed the water level change over time. The rate of change of depth is linear and implies a slow flow of water out of the system. It could be evaporation but this presumably only occurs across the surface of the water and would change as the surface area changed.
Cathedral was dived by Ben Nurse and others from SSS in 1957 to make a Marmite commercial for the Sanitarium company. The promotion indicated that if you ate Marmite then you were more likely to engage in exotic activities like cave diving. I had assumed that the lake did not go since it had been dived and that it had been reported as drying right out in drought. We went to look in Buggery Hole which I was sure no-one had looked at. Buggery Hole was found by some person who smashed their way through a flowstone right next to the Cathedral lake. This meagre success seems to have inspired others to try to smash through the flowstone draperies in Thunder Chamber and also on the main formation in the Ballroom. Flowstones in Cathedral have, in places, formed over the top of mud banks. The mud has then been eroded by a continuing water flow. In Buggery Hole this water flow forced its way into a hole in one wall droppings into a small chamber and into a spa-sized lake. The space beneath the dropoff often fills with an unbreathable concentration of carbon dioxide. We often collect water sample from here by tying a sample bottle onto a string and persuade it to sink into the pool. Sometime the air is sort of okay but you need a tape to get up and down the pitch. Simon McCartney dived this hole. It was reported to drop into a bedroom size chamber, sealed, smooth-walled and going nowhere. Buggery Hole might therefore be a small prototype of the other Wellington ponds. It appears to be isolated although located within 5m of the Cathedral Lake. The same day Simon dived to Buggery I had a snorkel in Cathedral Lake, just "to get wet." The floor is filled with interesting debris and I found a hole. Once I had moved some of the rocks that had fallen into the hole out of the way, it looked big enough for a diver so I went to find my dive gear. It was wriggle to get through the hole but it opened up into a large chamber. I had a very quick look about but was intimidated by the prospect of a return trip through a small hole hidden somewhere in a custard I whipped up thrashing through the squeeze. This is a hole best kept for hip mounts and that is the way we did it ever after. Simon dived it and Ron Allum had a go and they both reported a tightening rift at the bottom and that it was unlikely to go. You never know for sure though.
Despite this evidence it is difficult to give up the underground river model. The entrances of Triplet Cave, the holes behind the kiosk, the Cathedral entrance, Gaspipe, McCavity and the dolines near its entrance have the appearance of abandoned swallets. The cave entrances lie in a line running north/south mostly along the slight rise in the limestone bluff. Perhaps once there was a stream flowing on the surface and being captured by the cave system below. If water flowed in on a continuous basis then it had to be transported underground to somewhere else. The entrance to Limekiln running down to McCavity looks like it has once taken lots of water with it mouth and tunnel to the lower chambers big enough to stand up in and more. The Long Tunnel in McCavity adds to this picture with the Long Tunnel again running north/south beneath the phosphate mine and suddenly stopping just before the boundary fence.
The first task of the divers was to collect water samples for Julia James. On the following week I would visit her in her laboratory and drop the samples off, I would smile and she would wince at the extra work and look most suspiciously at our measurement of pH. Nevertheless, Wellington now has had THE most sampled water bodies of any cave. The content of calcium, magnesium, sodium, potassium, HCO3 and NO3 ions were determined. The water chemistry, we hope, can give clues as to whether the water bodies are connected. The chemical composition of Buggery Hole and Cathedral Lake are so different there can be little doubt that there is no connection. The chemistry of McCavity has been the same for all water samples that we have taken since we started and it is different from Cathedral. The chemistry of Anticline appears different again and the most radical difference of chemistry appears in the Bell River, which is very salty. Any notion that the Bell feeds the aquifer may be quickly discounted. The evidence of chemistry to date infers that water bodies at Wellington are perched and independent. Confirmation of this could be obtained from a theodolite traverse to all of the water levels that their surfaces are at different heights. This is not altogether easy since nearly all the water bodies are located down a small passages almost out of the realm of a theodolite.
Gaden Cave is the smaller of the two tourist caves. The map of Wellington by Oliver Trickett indicates that the entrance to Gaden was blasted open. There are some attractive formations and crystals and recent lighting developments in the cave effectively highlight attractive aspects of these decorations. The bottom chambers of the cave contain a mysterious pit from which a great deal of carbon dioxide is emitted. At times it rises from the shaft in quantities great enough that the tourist cave above has to be closed to the public.
The amount of carbon dioxide emitted from the CO2 Pit is staggering (pun intended). The big question is "Where does it come from?". Emission rates seem to cycle in relation to the weather, the time of day and the time of year. The CO2 Pit breathes out and is at times quiescent but I have never seen it breathe in. If it did then good air would be drawn down the shaft and there would be an opportunity to descend into the cave without breathing apparatus. This chance has never presented itself. On rare occasions that the quality of the air improves down the shaft but beyond the overhang at the bottom of the pit the air is bad even though the chamber on the other side is not very big.
Years ago management tried to alleviate the CO2 problem by filling the pit with rubble and sealing the top with concrete. It had little effect and the carbon dioxide found another fissure through which to fill the tourist cave. Exploration of the first shaft room down the pit using breathing apparatus reveals there is an aven rising to a passage above the CO2 Pit though a lose jumble of rocks. From here there is tunnel connecting to the centre of the tourist section. Recent renovations relocated the entrance stairs immediately above this shaft and thereby has more effectively channelled the foul air to the outside world.
SSS reported many years ago a period when the pit was free of foul air. This was before the pit was filled and they were able to venture down the shaft under an overhang into a small room. Here they could look down a shaft but their group decided not to go down because it was not safe - a very sensible conclusion. Since the filling of the pit, most of the dirt has been swallowed by the cave.
Normal air contains about 20.9% oxygen and 0.3% carbon dioxide. Fazer (SUSS Journal 5(1) pp3-10 1958) reports measurements of carbon dioxide reaching 12% with oxygen at 22%. Armstrong Osborne (Helictite 19(2) p51) reports levels as high as 9%. The carbon dioxide is therefore not produced at the expense of oxygen. What is interesting about this atmosphere is that although it is recorded to contain an almost normal percentage of oxygen, the foul air will not support a burning cigarette lighter.
The theory that CO2 is produced by micro-organisms metabolising oxygen is unlikely to be true, since none of the oxygen has been consumed. Armstrong conjectures that it is possible for the CO2 to be created in the sediments by biological activity and then diffuse through the soil but this is still in conflict with the observation that there is no oxygen depletion. If oxygen can diffuse into the soil so that the micro-organism can metabolize the oxygen then why doesn't the CO2 diffuse out the same way? What mechanism could account for CO2 in an oxygen-depleted environment diffusing into an environment with near normal oxygen? The soil would have to be porous enough to transport gases but the soil is compact and muddy. CO2-producing biological activity would have to be near the surface since the micro-organisms need a source of oxygen, yet Gaden's production is coming from a source at considerable depth.
Armstrong also considers the possibility that rainwater picks up the CO2 in the soil and transports it in solution to some underground body of water. I like this theory because it seems the most likely mechanism and also it is the most romantic in that it predicts a large underground lake as the source of the CO2. Gaden's CO2 emissions are phenomenal and this implies that the lake is very large.
The popular explanation for the dissolution of limestone proposes that carbon dioxide dissolves in rainwater and that when calcite rafts precipitate on the surface carbon dioxide is given off:
CO2(g) + H2O(l) HCO3- (aq) + H+(aq)
The surrounding limestone (calcium carbonate) is dissolved creating a solution suspending calcium and carbonate ions:
HCO3-(aq) + H+ (aq)+ CaCO3 (s) Ca2+(aq) + 2HCO3-(aq)
This is a reversible equation whereby carbon dioxide may be given off as limestone is precipitated such as in the formation of calcite rafts:
Ca2+ (aq) + 2H2CO3-(aq) CO2(g) + H2O + CaCO3 (s)
If the atmosphere above the water was air with a weak concentration of CO2 then CO2 would be given off. In a cave the CO2 is contained on the surface in very high concentrations and this would tend to force CO2 into the water rather than the reverse. Partial pressure doesn't explain the diffusion of CO2 out of the water.
A temperature rise can cause CO2 from gassing and precipitation. This theory is attractive because it is a reversible process which would explain the take up and expulsion of CO2. The temperature of the body of water in McCavity has been regularly monitored and remains steady at 18.5oC. On our most recent visit the temperature rose to 20.0oC but there was very little CO2 (the chemistry has remained stable as well). Temperature is unlikely to be the cause of the off gassing. Off gassing might be caused by the dissolution of another unrelated substance such as the froth and bubble observed dissolving sugar or salt in soda water. If this is the mechanism then the solute must somehow be removed from the water otherwise it would not permit CO2 storage at all once it was in solution.
One of our projects is to enter the First Pitch Room and excavate the debris that was used to fill the pit which is covering an entrance to another pitch and explore the realm beyond. We obtained full face breathing apparatus and descended the CO2 Pit using air cylinders in tank packs worn on our backs. We have spent 6 hours in the First Pitch Room experimenting with gear combinations in these working conditions. We used a variety of different sized diving cylinders as an air sources and a variety of regulators, full face breathing gear and hookah hoses.
The entrance to the pitch has been completely cleared with a working area cleared at the head of the pitch. With the view down the hole clearer, it is apparent that it is not really a pitch, but a steep incline and not a lot of room to move. Rocks tumble down the slope and audibly enter a room below but out of sight. Half way down the slope it gets a bit tight. In a normal atmosphere it would be easy but until a way to make the climb is devised to increase the margin of safety the exploration of the hole is on hold.
We at times had visitors on our trips and we would make an effort to involve them in the work. The trouble is that it takes a couple of dives before a new person can become independent, understand what it is we are doing and then become useful. At times the extra people meant it was going to take a long time. Sometimes, I would not dive and instead just helped transport gear and other times I just got in the way. Naturally while waiting in the silence in the lower chamber for divers to return it was natural to investigate any potential spots. I had a favourite place about half way up the cave and would move rocks around at every opportunity. This was sometimes to the consternation of the others since the inevitable spray of dirt and rocks made its way down to the lower rooms and threatened the camera equipment. Fortunately the group tolerated my foibles although I was usually a target for jokes about hopeless causes.
One week the hopeless cause breathed more than usual and I doubled my efforts. Gordon's son Sean was the first through. His size was about right so I sent my probe through the tunnel into a room where he excavated from the other side. It happened to be on a day that the State Emergency Services were visiting. They heard we were diving in the cave and so we showed them what we did. They eyed Sean's activities with some trepidation, suspecting that this could be their first cave rescue. Gordon was informed by one of their radios from within the cave that Sean was down some hole exploring a new cave. I don't know if Gordon was worried about his son being used as a scout in crumbly rock pile - there was concern in his voice but Sean was unstoppable. There was to be no cave rescue here. Sean was not keen to leave voice contact; children are much more cautious than people think. The truth, I suppose, is that Sean had gallantly left the heroic exploration for me. Far be it for me to turn down such opportunities, I thought, and slid into the hole. The squeeze widened into a room from where a sloping bedding plane squeeze cascaded over a pitch. The rocks that tumbled into it occasionally went "splosh" (a good sign). I squeezed through, head down, and wriggled through the dirt. The flattener dropped steeply but it soon widened. I hung, bat-like, into the space of a small chamber but with no handholds to permit further commitment. This would have been easier feet first, I thought to myself.
The trouble with NiCad lights is they die all of a sudden with little warning. My light died. All the dirt pouring around my ears was falling into a pool of water beneath. Just so long as Mike Lake doesn't get to hear about this, it'll be okay. I wedged my toes into a niche further to the rear and started winching my precious body back up the shute.
It was not until the following month that the lake under the drop was found to have a dive line in it. These are the chambers known as the Hanging Swamp. It is not a good entry for diving because of the squeeze and the pitch and neither are altogether stable. Ian McCullough convinced Brian, one of the Guiding Staff, to weld a few 3 inch water pipes together and make a scaling pole which we have used to get into the upper reaches of the Hanging Swamp.
The discovery of the land connection into the Hanging Swamp was kept from Mark. The next diving trip was on April 1st. Greg obtained from one of his friends in a sound studio a recording of two Sargasso Sea turtles mating . It was a most peculiar sound. We planned to convince Mark to go the Hanging Swamp on his own to get some photos. While he was would enter from the other way and hide in the roof with a tape player playing the sound of the thrashing sea turtles. We could have had weeks of fun laughing at his story of strange sounds in the roof of the caves but, alas it was not to be. On April he was wound up and serious about getting the multiple exposure shot right and the mood was not one for joking around. There was no chance of getting Mark to go off on a secondary trip and so we forgot about the joke. Mark was concentrating on the job with a considerable determination. On one ocassion a rock dislodged from the upper reaches of the cave and crashed into the lower chamber hitting Mark on the head. It split his helmet down the middle and he went on working only noting in passing that his helmet had just prevented a very nasty hole in his head. He proposed wearing the helmet on later trips as a sort of mascot but we felt the 9 lives were gone from that hat and we disposed of it in a garbage bin.
The Hanging Swamp has one lead left in it marked by a hole leading into a flattener that is heading north.. Phil Maynard came up one weekend and crawled along a miniscule flattener which crossed over a shaft that drops to water. It continues (just) through a very tight squeeze chamber and then up and into yet another chamber...and so on. He was on his own at the time and chose to return. Phil had already distinguished himself by abseiling into a shaft with no ascending gear. Not such a bad plan except that the bottom had high concentrations of carbon dioxide. We were able to get a rope to him and he climbed up the shaft far enough to get out of the foul air but the message was...be more careful.
David Jackson and Martin Scott came one weekend and I attemped to accompany them following the steps (slide-marks?) of Phil. I became particularly stuck on that trip but did manage to get the whole distance after some great effort. We finally stood in a room with a breeze drifting out of a rock pile that none of use dared to climb because of its unstable nature. Well, Martin tried a bit and David and I cowered under an overhang as boulders rained down all around us. There is an extremely large boulder poised ready to block the return journey and held by two smidgeons of mud on each side. It is necessary to climb over this boulder through a tight squeeze, hence called the Squeeze of No Tomorrow. There is good potential in this last chamber but it will need a lot of consideration.
I returned with Rob Collins to dive the water down the shaft in the flattener. I was originally going to just stick my head in the water with a mask to see it it was person-sized under the water but it led off and round the corner. Rob prevented me from doing a Norbert Castere and offered to do the return trip to the surface to get a pony bottle as safety. I stood inside the fissure with my feet in the water looking down the extra thin flattener thinking how easy it looked for Rob to rattle down that very flat flattener. I turned my light off and it seemed like an hour passed. A number of bats whipped up and down the flattener and grazed my head. Rob returned, bottle in hand, and after all that I had to go. The water went round the corner and into a hole that went down a long way...for a scuba rabbit. I looked about, checked my watch, logged a dive at 90 seconds and returned. Rob was philisophical and we called it a day.
Most of the time everyone has a job and all too often we are too ambitious in what we would like to achieve and only a fraction of the plan is realised. Nevertheless on one occasion had the opportunity to dive on my own just to look around. I went round to the North West Passage, the westernmost arm in the Hanging Swamp. There are some little holes that people had avoided because they are fairly silty. With some care I negotiated through one of these tunnels and came out in yet another north-south passage in a spectacular rift that curved up into the roof, around and out of sight. There were places to get out of the water but I was unsure of the air, possibly because I was alone. Nevertheless I resolved to return with company.
Testing CO2 levels seemed to be an important ability. The best way is with a Drager CO2 tester. This device contains a bellows that draws air through a rubber hole. The tester comes with a set of glass tubes tapered at each end, a scale marked on the outside and filled with clear crystal. You break off each tapered end of the tube, insert it in a hole in the bellows and pump the bellows. The bellows is just a way of drawing a specified volume of air through the crystals which then change colour in relation to the concentration of CO2. We decided to devise an underwater version that would cost very little.
I didn't get to make the next dive so I asked Greg if he would
test drive the new CO2 tester. We used a
plastic bottle stoppered with a cork with two holes in it, one
with a plastic hose coming out of it. When Greg surfaced in the
new passage he placed the glass tube from the Drager in the hole
in the cork and then allowed water to siphon out of the bottle
and draw air through the tube. The plastic bottle had a line
marking the level represented a known volume where the water flow
should be stopped. The carbon dioxide can then be estimated from
the discolouration of the crystals against the scale on the glass.
The commercial Drager CO2 tester provides
a handy metal hole into which you place the end of the crystals
tube to break its ends off. I had not considered we would need
this. We could do without such frivolous conveniences. I suggested
Greg should used a crack in a rock or something. Of course in
the field everything is always more difficult. Inside, the rift
the walls were found to contain no suitable cracks. It is hard
to improvise when you're floating in bulky dive gear so he broke
the end with his hand, managing to slice open his hand. He did
manage to complete the test and the air tested "okay".
When he returned to the Hanging Swamp he was a bit grumpy and
trailing blood in the water. He recommended the addition of a
frivolous glass breaking tool and we all said he should watch
out for sharks.
Merv Maher decided to investigate the Cathedral Lake. Here came yet another surprise. Merv started using hip mounts for Wellington dives to ease the entry through the narrow birthing canal in McCavity. Without the back mounts he could pass the squeezes in the Cathedral Lake more easily than previous divers. The lower chamber was found to connect to another chamber and this one connected yet again to another chamber and from here there is another constriction into more passage beyond. Each constriction has a silty floor and may be excavated but this results in total silt out conditions. We convinced Merv to spend time taking compass bearings. Instead of heading towards the large body of water, McCavity is instead heading north, perhaps towards Triplet Cave. Triplet is clearly a significant water collection sink but has no cave at the bottom of it. It may be worth digging.
The connected river view of the cave system is lent more weight. Merv has done the dive in Cathedral Lake several times and is clearing out the sediment in the connection between the chambers. They are tight and the small confines of the cocoon need to be more comfortable before pushing on long penetrations.
Allowing myself some wild speculation I shall make some predictions I think there are at least two more lakes such as McCavity that will be found. The bottom of the main pitch in Limekiln has a lake on the right hand side, at the back of which is a hole that is too small to negotiate with scuba but is negotiable in times of drought. There is potentially another body of water connected to Cathedral that Merv has been trying to find and this is possibly the same extension to the north of McCavity. I am sure there is a lake under Gaden and the CO2 pit goes to it. There is an extension to the Anticline Cave but this might be silted up.