Oxford University Cave Club

Summary

Pozu Jultayu (2/7) is one of the most significant caves in the western Picos de Europa. After an entrance series of tight rifts and a 500m shaft series the cave opens out into a massive high level "The London Underground" overlying a large active main drain. Both the high levels and the stream end in a huge terminal boulder choke "Egbert" at a depth of 820m. With a further drop of 800m to the resurgence at Culiembro and wide-open upstream leads, 2/7 was the focus of exploration for the OUCC Jultayu 1998 Expedition.

Two underground camps were established, a 6-person camp near Egbert and a two person camp on "The Big Ledge" where the main drain is first met. The assault on Egbert consisted of investigating a number of drops, climbs in the high level passages preceding the choke as well as several digs in the choke itself. Tantalus, a promising, pitch in Soup Dragon, was re-discovered and surveyed, only to find it was an inlet back to the main stream. Bold climbs were made out of Postman Pat, Soupdragon and Bod, but only Bright Lights, a 60m bolt and mud slope climb, yielded promising new passage "Hunt the Crowbar". This too, however, ended as an inlet to the main drain. Closer to Egbert, climbing out of Pimpernel Streamway led into "Pixie Steps" an extension of the high levels in the area of Colostomy Choke. These passages, however, also choked downstream.

Egbert itself drafts strongly in a number of places, which suggests more passage beyond. We concentrated digging in three areas: Tim's Bit, The Flood Overflow, and The Calcite Choke. The Calcite Choke along the left-hand wall of Egbert proved solid and difficult digging, so was quickly abandoned. More progress was made in the muddy undercut at the end of Tim's Bit, the furthest point reached in the choke. The solid roof eventually gave out into cobbly hanging death so this too was abandoned. At the end of the expedition efforts concentrated on The Flood Overflow, a clean washed boulder filled passage directly beyond the two stream sinks. This consisted of a more or less solid roof and walls and an easily dug floor. About a meter of progress per day was made with the strengthening draft and sound of running water drawing us on. Only the end of the expedition and the need to go home prised us away from the dig, which now remains a very promising downstream lead with anything between 2m and 2km between us and the passage beyond.

Well over 1km of passage was found elsewhere in 2/7. The largest discoveries were made upstream where we found 700m of beautifully sculptured stream passage "Cherrypickers". This ended in a 10m waterfall "Viagra Falls" just after a large inlet. The climb round the waterfall will require only one or two bolting trips to pass and who knows what lies beyond. The survey suggests that this point lies less than 500m distant and 50m below the downstream limit of the 640m deep Sistema Le Verdelluenga (C3/C4), so the prize of connecting the caves of Ario and Top Camp may be within our grasp. New passage was also found in the entrance series. An alternative shaft series, "Tumbling Dice" had been left at a hammerable rift. When hammered it revealed another 40m of passage to an undescended pitch. Even if (as is likely) this intercepts the known cave it will provide a swifter, easier route to the depths of 2/7 by bypassing much of the entrance rifts.

On the surface, drafting digs were investigated in the Valley of Dry Bones and Valle Extremero, which lie above the London Underground. Most progress was made in Dry Bones where the treacherous surface layer was broken through to more stable ground below with incredibly windy passage ahead. Further afield the area between Cuvicente and La Verdulluenga received more attention than in previous years, with many new entrances found and old caves pushed. The most significant discovery was 27/9 on Gustuteru. This dropped in six pitches to a depth of around 100m with a strongly drafting tight continuation. The cave lies directly over the C3/C4 sump and was dye-traced to upstream 2/7 and to the Culiembro resurgence. This dye-trace again points to a connection between the two systems and the potential rewards of continued exploration in this area.

Overall, OUCC Jultayu 1998 was a highly successful expedition. 25 people contributed to downstream exploration with over 150 person days spent at the underground camps. The most promising downstream leads were thoroughly investigated with the Flood Overflow remaining the most likely route to passages beyond (given time). Elsewhere in 2/7, we have several exciting open leads and on the surface there are good prospects of dropping new entrances into both up and downstream ends of the cave.