by Tim Francis
(click images to enlarge)
Our fourth visit to the caves of Malargüe and finally we've found something for the press to write about:
La cueva hallada sería parte de un gran sistema de ríos subterráneos Walter Aquindo (Los Andes): La expedición anglo-argentina de espeleología que descubrió la caverna de yeso más extensa del país (Los Andes de ayer) y posiblemente de América Latina, espera poder profundizar los estudios de esta "maravilla", como ellos la definieron. A su regreso a Malargüe uno de los integrantes, Ariel Benedetto, detalló aspectos del descubrimiento que abre distintas posibilidades de investigación y se agrega a recientes hallazgos similares en las inmediaciones. El descubrimiento lo hicieron el martes 11 de febrero, los espeleólogos Tim Francis, Rubén Cepeda, Richard Carey y el mismo Ariel Benedetto durante la tercera Expedición Anglo-Argentina en el sur mendocino.
This year our key goal was to try and push the end of Brujas as we had managed to obtain permission from the park authorities to explore it. This was to be the first time in years that cavers would be able to obtain access to the system and both the MCG and INAE were keen to take advantage of this opportunity. However we also wanted to tick off a few loose ends we left at Poti Malal last year and perhaps even explore new areas of gypsum if the weather and transportation permitted. As it turned out our two days caving at Poti Malal rather than Brujas were to be the most fruitful.
Cueva del Tigré
Just a bit of housekeeping here really. Since the removal of the fixed ladder in 2002 there was no suitable rigging point for the entrance pitch apart from some extremely dodgy homemade bolts, a few shrubs and blocks of lava. I put in three 8mm bolts to allow a nice free hang for either ladder and line or SRT. A slight flaw was that I'd remembered the bolting kit but left the hangers at home. These were posted to Rubén, INAE tackle master, after our return to England. An interesting point to note is that there were considerably more bats roosting in the cave than we had seen in all of the previous years. One can speculate that this is due to fewer disturbances to the colony as the tourist visits have been restricted by the removal of the ladder. Perhaps an annual count should be conducted to monitor trends?
Caverna de las Brujas
We had previously made a cursory visit to Brujas in February 2000 as part of the Caving Conference but we had seen no more of the cave than the standard tourist route. And above ground we had made a half day's visit to the valley of Chacay - Co in 2001 but only spotted one small fossil remnant. This year we wanted to look at some of the extreme ends of the cave to see whether there was anything worth pushing. The cave is located in a sizeable chunk of Jurassic limestone and at 2500m + is currently the longest cave in Argentina.
In the event we only made two trips into the cave itself. The first was a scramble around the northern and Eastern corners. From the entrance several fossil galleries run northwards with a strong geological control determining the passage direction. We followed the most easterly gallery which is accessed by dropping straight down in the floor below the tourist route just after the entrance chamber. This area is quite confusing but the survey is pretty good once you've worked it out. After checking out every hole we headed off down Arcita Fosilizada, which is the main route to the back end of this part of the cave. This proved to be quite a sporty rifty section and nice and sharp which made for some pleasant climbing. Richard had a good play with his new digital camera. At the far end the rift closes down at an aven but it does seem to draught well. There were a couple of climbs in the roof, which I didn't tackle so there might be a way on. On the way out we spotted a bolt and a pitch down in the floor. All our kit was back at the tents so we didn't descend this but it's not on the survey. The national park guides at Brujas reckon that there is connection between this and the next rift at Chimenea de Arcilla.
Sala de la Madre
This must be the best tourist trip underground in Argentina. The route into the western part of the cave is via a nice tube on the left after the entrance chamber, Galeria del Tigre. The way in is not that obvious but is a small flowstone squeeze on the left, very reminiscent of the Mendips. This is a fine bit of passage and becomes progressively larger. The floor starts to drop away and one is forced to traverse along at roof level passing some fine formations on the way. Later on we discovered that we were probably the first people to head in by this route. The normal route is to follow the floor down and then slip down a chimney just above the entrance to Sala de la Madre. We carried along at roof level making some 'interesting' climbs before finally dropping to floor level at Galeria del Pez. As this roof traverse is not marked on the survey we were a bit confused and didn't actually pin point where we were until we got to the far end of the Galeria. After a quick consultation of the survey I pushed a rift at the far end along a very narrow section. This does draught but finally ends in some tight tubes with a cluster of nice helictites. We then spent a merry 30 minutes looking for the way on to Sala de la Madre. This is actually at a lower level than we'd expected. From here it was tourist time with Richard's camera going into overdrive. There are some fantastic stalactite grills at the far end, which are nothing like anything else in the cave. The sumidero marked on the survey at the end of Madre is definitely not a canyon and definitely closes down. There is therefore no other way out of the chamber.
Afterwards we decided to check out some of the question marks in the blank area on the survey between Pez and Galeria de Los Pinitos. In this area the survey is incomplete and to be honest needs redoing. For instance both passages in the area of Galeria de los Fósiles close down and do not connect with Sala del Libro. There is C.A.E. graffiti and an I.N.A.E laminated sign at the end of the low level passage. So I'm reasonably certain that there is no connection here. But there is definitely one connecting passage at the Tigre junction as we bumped into the two chaps from the National Park who had come in for a wander to see what we were up to. They lead us out via an alternative route to Tigre. Volunteers for a survey?
Other sites in the Brujas national park
Above Brujas is a large lump of limestone. We spent a couple of days wandering around looking for other caves. We covered the whole of the limestone block nearest to Brujas including the cliff face over looking Canada de los Enamorados. There was absolutely nothing here apart from a small 8m tube, the home of a chinchilla. But one area that at first seemed extremely promising was a large dry valley above Brujas to the North West. Long lines of fault-controlled rifts run along the bottom, several of which draught strongly. We hoped that they might provide a top entrance to Brujas but it soon became apparent that this was not to be. A few needed digging into whereas one was huge. None showed any sign of cave potential and I think what we've got is a series of windypits.
Brujas itself sits at the end of bowl shaped valley with limestone hills all around. One evening Tim and Ruben went for stroll along the south and eastern side. We covered all of the hills but didn't find anything other than a few cracks and well known existing caves - Las Cabras, del Viento and Tucu-Tucu. These are very small ancient caves and not of great interest. The steeply-bedded limestone in the area means that most of the modern rainfall just runs straight off so I don't think there will be any more recent caves.
Cueva de los Jotes
On the same evening as the 'Tim and Ruben' ramble the park guards showed us an entrance about 30 minutes walk from Brujas, on a bearing of 195° from the house. The entrance is right at the top of the cliff overlooking the Chacay-Co River and really is an ancient piece of cave. The following day we all returned to explore and knock off a survey. The cave is an 80m remnant of an old system but well decorated throughout. Much of the stal has been broken as a result of earthquake activity but still very attractive. The end is completely blocked and probably still lies very close to the cliff edge. (All that remains is for me to draw up the survey, perhaps in another article in the future).
After all the fun at Brujas we only had a couple of days to spare to do some more exploration in Poti Malal. Our first trip was to look at the two huge new chambers discovered in San Augustin by the Croatians. These are extremely impressive and a great discovery. Again this is something that needs surveying but we didn't have time to do this on this year's trip.
In the afternoon after our visit to San Augustin I thought I'd show the others some of the features in the Miranda valley. Little did I guess that we would make our best Argentinean discovery so far. Last year myself, Peat and Jules spent over a week wandering all over the gypsum at Poti Malal but failed to find anything significant. On the last day we nosed around in a small resurgence near the Miranda farmhouse as the log reveals:
"On the way down just across the road from Miranda's farm we spotted another resurgence. This was larger than the one by the cars and looked pushable. So reluctantly I dumped my rucsac and went for a look. I suppose the best way to describe the thing is that it was an Argentinean version of Springwell Rising, Fermanagh. I wriggled up the resurgence for a couple of body lengths but lacked the enthusiasm or energy to continue. Next year?"
As soon as we caught sight of the resurgence from a different angle the obvious location of where a cave entrance might be became apparent. Ruben nipped around to the back of the small cliff face where the water emerged and shouted that he'd found a cave. It was literally 20 feet away from the horrible thrutch I'd pushed in 2002. Essentially it was a window into the streamway that bypasses the final low bit.
Myself, Richard and Ruben crawled up the resurgence for 10 minutes or so before the water was found to emerge from a 3 inch bedding plane. But a dry overflow carried on for a bit further until it too was stopped by a too low bedding. Back from the end we spotted a way on off to the right that looked interesting. Unbelievably this continued on and on and on. The passage was like nothing we had encountered in Argentinean gypsum caves before. Low, crawly, wet and muddy. Ugghh. After 15 minutes of hard-going passing a few roots in the ceiling the passage popped out at the top of an aven. We could hear a streamway! A 30ft free climb and we were able to peer through a low grovel into the stream. Reluctantly we wriggled though to enter a parallel passage, perhaps crawling in height. Both upstream and downstream were given a cursory look but both seemed a bit desperate for us with only our minimalist caving gear.
We elected to climb back up the aven and follow the roof. This carried on and on with some fine sharp flakes and chossy traverses above a deep rift. Eventually the floor rose to meet the ceiling and it became tube-like again. We soldiered on, determined to push it to the end despite our aching knees, and so we were rewarded with another short piece of stooping-sized passage. The streamway was rejoined with low continuations upstream and downstream. At this point we called it a day as we were in bits and further progress looked desperate. (Ruben has since pushed on a little bit further to a cascade). It's hard to tell how long the cave is but it took over an hour to exit so I guess we're looking at 600-800m. Once all the passages have been explored I should think the cave would be longer than 1km and the longest gypsum cave discovered so far in Argentina.
Other sites at Poti Malal
Whilst the others looked around the 2002 extensions in Doña Palmira I started a dig at the end of the phreatic bore, just beyond the breakthrough crawl. This didn't go so I think we'll need to dig in the vadose trench at the end of the old cave.
We spent half a day looking around the other sites in the Miranda valley. Ruben and I chiselled away at Burning Man dig, and eventually he was able to squeeze in. He reported that it doesn't go far. But after the discovery of Miranda anything on this side of the valley will be worth a look.
Ruben had spotted another piece of gypsum further along the Pincheira road, about 2 hours drive from Malargüe. Unfortunately it involved a bit of a soaking crossing a river to reach. We literally had only an hour of surface recce before we had to head back. At first glance the gypsum didn't look that good, and very weathered as at Pincheira. But the gypsum does head off southwards out of sight so it may be worth another year.
Thoughts for 2004
Richard has been out in Argentina since August and is putting in some excellent legwork (see MCG newsletter 316) for our next trip. Undoubtedly he will have additional ideas to add to the following:
The Chacay- Co River. Presumably there is an air connection between Brujas and the valley side in the area beyond Galeria del Pez. There is also the question of where the Brujas water ends up. I haven't quite got my head around the geology but it might be worth looking for resurgences in this area.
Brujas. The main problem here is that the survey of known and rumoured passages needs to be completed before we can be sure where to look. But the cave seems to be essentially made up of three parts. A section to the north and east, which consists of a series of fault-controlled rifts; a section to the west with a large chamber (Sala de la Madre) and rifts running east/west where the water would have joined the main cave and resurged at Brujas; and the modern active cave, which we didn't visit. Apparently the Croatian cavers tried to follow this route but didn't get too far so it might be worth another look.
Jurassic limestone. I think we might be able to access the Northern end of the limestone by walking in from the Pincheira / Malargue road.
Miranda. The major objective of 2004 will undoubtedly be to push the cave to a conclusion and complete a full survey. To this end we will be taking out Mendip-style caving clothing so we will be able to cope with the cold water and long sharp crawls.
Poti Malal. Doña Palmira might be worth another dig if we have time.
Richard mentioned the possibility of another slab of gypsum in the valley beyond the border post at Poti Malal. It would be great to open up a new area of potential.
Richard Carey, Tim Francis (MCG), Rubén Cepeda, Ariel Benedetto, Carlos Benedetto, Diego Sánchez (INAE)
Mendip Caving Group. UK Charity Number 270088. The object of the Group is, for the benefit of the public, the furtherance of all aspects of the exploration, scientific study and conservation of caves and related features. Membership shall be open to anyone over the age of 18 years with an interest in the objects of the Group.