1981 Expedition: "Ario"
Picos de Europa, Spain
See also OUCC Xitu expedition 1981 logbook (pdf)
This pamphlet is intended as a preliminary report of the 1981 O.U.C.C. Expedition to the Picos de Cornion, in which Pozu del Xitu was explored to a depth of 1139 metres. A complete report of the Expedition will appear in 'Proceedings O.U.C.C. 10', to be published this Autumn.
Note: The numbers in parentheses in the text refer to the references, which are listed at the end of the report. The survey is located on the final page.
In 1979, O.U.C.C. organised an Expedition to the Picos de Cornion, the Western Massif of the Picos de Europa, in Asturias, Northern Spain. Quite close to the end of the Expedition a party was sent from the base camp at Lago de la Ercina up to the Ario Plateau, where they discovered Pozu del Xitu. Tackle was freed for the cave during the last week of the Expedition and it was hastily pushed and surveyed to a depth of three hundred and fifty four metres. (1)
In 1980 an Oxford team returned to Ario and explored Xitu to a depth of eight hundred and fifty nine metres, where they ran out of tackle. (2) By the end of the Expedition, trips to the limit of exploration were taking twenty four hours: it was plain that an underground camp would have to be set up in 1981.
Armed with newly purchased camping gear, nearly two kilometres of rope, a quarter of a kilometre of ladder and a Club Land Rover to carry it all in, a larger-than-usual Oxford Expedition left for Spain on the fifth of July. As in 1980, Xitu was our main objective although man other caves were explored in the hope of finding an easier or higher Xitu entrance. Around forty such entrances were examined and all, bar one, choke, become too tight or arc plagued with massive ancient snow plugs. Two of the 'too tight' class could have been pushed had we had a small amount of 'bang'.
The cave which actually 'goes' is extremely tight and chossy, and what's more, it doesn't head for Xitu. It was discovered too late in the Expedition to be pushed far or surveyed. It seems that 'the extremely shattered nature of the limestone' (3) and the snow b1ock most of the sizable caves in the area arid that we have been exceedingly lucky to find the entrance to such a large system as Xitu.
And so on to Xitu itself. A last desperate pushing trip from the surface managed to rig the final 1980 pitches along with two further new pitches. After thirty six hours caving, the pushers returned to the surface with the news that the cave had run into a very sharp, tight rift which led eventually to another pitch, as yet unrigged. Armed with this information, the first camping party went down the cave with two tackle bags of camping gear each and set up camp in the boulder chambers just below Pythagoras Pitch (62m), at a depth of around seven hundred and ninety metres below the entrance. Once the camp was established the exploration of the lower half of the cave proceeded much more efficiently and the terminal sump was found by the second camping party.
Below the camp the stream heads through vadose passage with deep pools to the head of a four metre climb in a waterspout known as PAFS (Piles Arising From Suspension) Pot. Later on in the Expedition this was laddered. The stream then runs into a tight, sharp rift, the Cheesegrater, which is best bypassed by following an old fossil high level. After a short section of Cheesegrater necessary to avoid a dire climb the passage opens out and the head of Choss-Chock Pitch is reached. Below this a short section of clean washed streamway leads to the top of Rape B'rape Pitch (40m), the limit of exploration in 1980. A long section of high vadose streamway with some deep pools and a few cascades follows and leads to The Flier, a fine forty metre free hanging pitch in a fairly spacious chamber. From The Flier, a series of cascades in dark slippery rock descend to the top of a five metre drop, which is bypassed via a traverse along the right hand wall (Traverse of Truth). The passage, which has until now been fairly roomy, degenerates into another tight, sharp hading rift. Ferdie's Delight (the name is a result of its effect on oversuits) is longer and nastier than the Cheese-grater but can also be bypassed by following a high level. The bypass finally emerges in a high vadose streamway, about two metres wide, at the head of Chunder Pot, a thirteen metre wet pitch. The stream is much larger here, having presumably been joined by other waters in Ferdie's Delight.
From the base of Chunder Pot, the cave continues in the same fashion, losing over one hundred metres in height in a long series of wet, sporting climbs and two short pitches, Campers' Pitch and Cobbler's Pitch.
Eventually one encounters the Depthscalator, another (but thankfully roomy) hading rift down which the stream runs. This is cut at right angles by a second rift, which now takes the stream. The water cascades down several drops which can be bypassed through an old high level to the final section of streamway. A slackening of gradient means that the stream flows sluggishly and that there are many deep pools. Traversing above these for over one hundred metres, one eventually reaches a brief section of wide passage with a shingle floor, which leads to the terminal sump. One brave expedition member swam around in the large, clear sump pool for some time and measured its depth to be at least nine metres.
In spite of some extensive searching, no bypass was found and so the camping parties set about surveying, photographing, bug collecting, dye testing and detackling, tasks which kept them busy for the next few weeks. The depth of Pozu del Xitu was finally calculated as 1143 metres to the lowest surveyed point in the sump.
Meanwhile, O.U.C.C. had not been idle in other parts of the cave and several new sections of passageway had been found. Notable among these are the Snow Castle, an inlet to the Teresa Series (2) and El Puritan, a passage leading off from Eton Palais. Snow Castle contains some of the finest formations that Expedition members had ever seen, outclassing any single piece of Otter Hole. Exploration of El Puritan was eventually abandoned due to fear of death.
So what of the future? Xitu is finished and the Ario plateau seems singularly devoid (with one possible exception) of other entrances to deep caves. However, to the South of Ario is the Joon, a remote ring of high limestone peaks as yet almost unnoticed by cavers. It says something for the potential of the area when an Oxford caver can walk into a stream cave at an altitude of about eighteen hundred metres on his first visit up there. So perhaps the Picos de Cornion isn't finished yet. After all, it does contain one of the deepest caves in the world already.
We would like to record our gratitude to the following sponsors and suppliers of equipment and food, whose assistance made the Expedition possible:
Many thanks to Nick White for supervising the renovation of the Land Rover.
Finally, we would like to thank the BCRA and the Spanish Caving Authorities (CNE and CRNE) for allowing us to work unhampered in the Picos de Cornion.