Oxford University Cave Club
Expedition to Northern Spain July / August 1973
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The 1973 Oxford University Cave Club expedition spent a total of five weeks in the field, and is pleased to be able to report the successful extension and exploration of several significant caves within the area bounded by the Rio de las Cabras and the Rio Sella.
The main body of the expedition left Oxford on July 4 and arrived in the Llanes region in Asturias two days later, without undue difficulty. It proved necessary to effect repair to the wheel hubs of the trailer in the area of Poitiers. Compared to the experiences of previous expeditions, however, the travelling, in both directions, was relatively trouble free.
It was decided that, although the Cueva Negra had the greatest theoretical potential, a campsite at Rales would be preferable, as it would provide both a cave within walking distance and better access to the town of Llanes. Accordingly, we negotiated with the owners of the bar at Rales, and were presented with a rather superior field adjacent to the Rio de las Cabras, the eastern boundary of the chosen area. Charging facilities for caving lights were also arranged with the owners of the bar. The camping aspect of the expedition was very successful; the villagers of Rales proved to be as friendly and interested as those of El Mazuco, where three previous expeditions had been based. Indeed, by the time we left the village, an unofficial speleological group, composed of the local youth, was presenting us with information on new cave entrances each day.
The bulk of the expedition's attention was in fact devoted to the cave, or caves, of Rales. We were rewarded by the discovery of a system with a total passage length of between 2-2.5 kilometres. The Cueva de Fuentica, immediately behind the village,had been looked at by the 1972 reconnaissance expedition. There is evidence that Spanish cavers have investigated the entrance series, which is dry. The first three days of actual caving were spent or exploring the streamway, using the maypole to scale the two pitches which were met. The streamway of Fuentica provides some very enjoyable caving. It is impressively decorated and contains sufficient obstacles to ensure that these formations remain protected. It was therefore with some chagrin that we found the character of the cave dramatically altered above the second pitch. Progress was halted by a low wet crawl blocked with small boulders. However on the same afternoon, we were taken up the valley behind the village to be shown an enormous cave entrance, taking a stream similar in size to that in Fuentica, and a cliff behind this sink with numerous entrances, one of which introduced the same stream. A link between the Pozo del Molino, the large sink, and Fuentica was subsequently effected by removing a handful of boulders at the end of the cave and immediately entering the crawl at the top of Fuentica. Investigation of the resurgence, known as Samoreli, revealed a short cave containing a chamber of impressive dimensions. The sump yielded nothing to free diving attempts. This cave could also be entered directly from the surface via a 10 metre pitch.
Considerable time and energy were devoted to the whole system, both in surveying and further exploration. The maypole was used to look at a high level in Samoreli. Numerous trips were made to look for a possible sink; although several caves were discovered or shown to us, no penetrable sink could be found. Further important discoveries were made towards the end of the expedition when we were effectively without transport. A short cave was discovered which led to the Pozo del Molino. The entrance series to Fuentica proved to he enormously complex new routes were discovered each time a party went into that entrance. Two days before departure a further series of large passages in the stream way beyond the downstream sump were entered and a second large chamber was discovered.
This whole system is therefore very extensive and will probably yield more passage to further exploration, though we feel that we have managed to explore the bulk of it. A fuller a description and the survey of the system will be included in the final report.
One other cave occupied almost as much of the expedition's attention, in theory rather than practice, since it is 25 kilometres from Rales. The Cueva Orandi is very well known to Oxford expeditions. It is situated some 270 metres above and about 1 kilometre behind the resurgence at the shrine of Covadonga, for which it is the probable sink. The volume of water sinking in the cave is not as considerable as that resurging, but nevertheless, sufficient to make the cave extremely hazardous. The sink was first explored by the 1961 Oxford expedition who reached a reported depth of 75 metres. The 1972 reconnaissance party went as far as the climb at the foot of the 20 metre pitch. Only vague reports were to be had as to what happened beyond this point. Our first trip was unduly curtailed by a serious mishap - one of the party falling 8.5 metres, fortunately without serious injury. Later trips showed that we would not have been able to go much further in any case since the cave was taking more water than usual. Two more trips were made to Orandi. The first involved exploration down to the sump at approximately 100 metres via 4 pitches, three of them wet. The passage beyond the pitches descends just as steeply in a series of interconnected potholes, most aptly described by one of the party as being like a slab of Gruyere cheese, set at an angle of 30 degrees. The sump is not immediately bypassable, but a large oxbow leads to an estimated 5 metre pitch which was not descended. The survey, which has just been drawn up, shows that the chance of a bypass is more or less assured, in so far as any statement of certainty can be made about this cave. It was intended to push this bypass on the surveying and detackling trip, but the pushing party somehow contrived to be never more than 20 metres in front of the surveyors and did not descend the pitch. This cave is extremely dangerous since its drainage area is very extensive. Flood debris is a constant reminder that one would have to have the cave very rapidly in the event of a storm. Nevertheless, there is a good chance that a through trip would be possible, though impolitic in view of the esteem with which the resurgence is regarded.
The main hope of the expedition, the Negra polje, did not live up to expectation. The actual cave, the Cueva Negra, has a surveyed length of 600 metres, and is a very fine cave whilst it lasts. It is essentially a meandering stream massage in the best tradition of Yorkshire caves, punctuated by two pitches. The limit of exploration was a tight flooded rift, which could be forced by divers, or indeed by a caver with a snorkel and a strong death wish. Another short cave (Cueva Lledales) of about 100 metres, in length was investigated, being adjacent to Negra. No other caves were discovered in the vicinity, which in view of the severity of the march to the polje was a relief to several members of the expedition.
Several trims were made to the area of the Cueva de Tinganón, above Ribadesella. A large number of photographs were taken in Tinganón, but since a survey of the cave was of low priority, it was not surveyed. The adjacent Abseil Cave, whose name has not been discovered, was explored and surveyed, bit yielded little in the way of new passage. This cave contains a number of fine decorations, particularly in the high level passage above the sump. The sump itself, artificially extended by a dam is a variable quantity. On the surveying trip it proved to have shrunk by 16 metres.. Records have been left by previous visitors, the earliest being October 1916.
The expedition also spent a considerable amount of time in the area of Mestas - Socueva, investigating the valley of the Piedra Hita and the surrounding hills, but finding little of significance. Several small caves were discovered or shown to us by the villagers. The cueva del Agua at Mestas was the scene of serious but unsuccessful sump pushing trip, so that the total cave length remains at 31 metres. The Cueva del Agua at Socueva managed to elude our searches, as did the reportedly bottomless holes above Mestas. The villagers are only too happy to lead cavers to these caves, but whether anyone would be capable of going down them after such a walk is another matter.
Some time was devoted to the area of Ardisana - Mere, and the valley of the Rio Blanco o caves of any consequence were discovered, but was found that some revision in needed to make the geological map more accurate.
The whole area around Rales was very thoroughly investigated. Several small caves were located. At the time, we were inclined to pay little attention to these since they did not go anywhere. However, the newest discoveries in Fuentica cast new light on several of these caves, particularly those above the blocked downstream resurgence.
Several trips were made to the Caldueño valley for the benefit of those who had not been present on the previous expeditions based at El Mazuco. A certain amount of time was spent in the Rotella - Villa area which lies between Rales and Cortines; two potholes were entered which proved to be rather short.
Despite fears beforehand, the expedition found itself with more than sufficient tackle to cope with all the caves which were investigated. The vehicle problem was more acute. The original plan had been to take two vehicles to Spain, but this proved to be impossible for financial reasons. The expedition was therefore dependent upon the single vehicle, which performed admirably under the circumstances. However, with eight as the average number, it was not always possible to allow everyone to pursue their own inclinations. Four days were spent without the car when it developed a major hydraulic leak and we had to wait for a delivery of fluid from Madrid. We were fortunate therefore that the Rales system proved to be far more extensive than appeared at first sight. Nevertheless, it is strongly recommended that any future expedition should try to have two vehicles available if it is at all possible financially.
Two days before we left Rales, a party drove to the area between Infiesto and Campo de Caso to make a cursory examination of the little known region of limestone there, which despite its close proximity to Oviedo, does not seem to have been subject to the attentions of speleologists. Several cave entrances were located from the road. The nature of the terrain is promising; tentative plans have been made to send a small reconnaissance expedition to the area next summer in order to look more closely into its potential.
The full report of the 1973 expedition, including surveys, photographs and a geological report, will appear in due course. It will be sent out at the earliest opportunity. See Proc OUCC (7).
Scanned in by Bill Collis.