Matienzo 1984

A summary of the cave explorations which occurred in Matienzo during 1984

amended from an original article in Caves & Caving 26 by Piers Barrington and Dave Hanson

A large party of cavers from various clubs returned, yet again, to continue exploring the caves in and around the Matienzo depression. The total of new passage discovered was nearly 6km, mainly in one system.

   With the discovery of the 2.2km long Trident Series in Uzueka (site 107) at the end of last years expedition, hopes were raised for a ”back door" to the system to eliminate the 16km round trip involved in pushing the end. Radio location showed the final choke to be only 30m from emerging into the Matienzo depression. This would have connected two of the valleys in the Four Valley System. A surface dig was started but had to be abandoned due to its instability.
    Another party poking around in Uzueka discovered Green Van Series (about 2.5km from the entrance) consisting of about 200m of passage ending in several unclimbed avens. This heads back towards the Riaņo depression and, if a surface connection is made would bypass a section of passage which often sumps.

   The 15.5km long South Vega System did not receive the attention it deserved due to Coteron (site 264) not being tackled up, although many leads were left over from last year. In the lower levels, steady work in Reņada revealed about 800m of passage although no outstanding tunnels were found. Further up the hill, Azpilicueta (site 333) was looked at with the objective of connecting it to Reņada, not more than 80m away. This predominantly vertical system saw the discovery of 0.5km of passage leading over Reņada, but the connection remained elusive. Another route into the South Vega System may come from Codisera (39). A bolt route started this year leads towards a roof tunnel with sizeable passage in view. Next year should see the completion of this.

   On Muela, an unexpected development happened when Cave of the Wild Horses (sites 509 and 647) was found. Instead of the usual choked shaft, some horizontal passage was discovered. Although not extensive by Matienzo standards (consisting mainly of two boulder chambers and a dead horse) it does imply that horizontal development has taken place.

   This years major discoveries took place in last years extension to Mostajo (site 71) which heads under Enaso (Caves & Caving 22 p16). Previously 1.3km long, the cave now boasts some 6km of surveyed passage. About 700m into the cave a hole 5m up the left hand is a window into the "Golden Void", a free- hanging, 34m pitch. From its base a clamber up boulders leads to a junction where the Cayenne Series starts. This was originally thought to be a large hading rift some 60m wide; subsequent surveying showed it to be a 60 x 7Om chamber with gaping holes in the floor and walls, none of which have yet been pushed. Further in, a 5m diameter, clean-washed shaft is passed (descended for 1Om to the top of an estimated 20m pitch). Shortly afterwards the "Going Everywhere" starts, with over 500m surveyed and numerous leads left for next time.
    After a short, convoluted section a return is made to 10 x 10m (standard Matienzo) passage where a large junction is met. Straight on leads to a pit. This has been seen from the other side via "Going Everywhere" series. Unfortunately the route has been lost and awaits re-discovery. Continuing along the main drag, numerous side passages are passed, many of which are still unexplored. This includes the maze which contains over 1km of passage with several undescended pitches. On an attempt to bottom one of these the ladder ran out 5Om down.
    After the maze, the cave changes character and becomes extremely well decorated, with chambers interconnected with stooping passage. From the final chamber, numerous ways lead off, the main one being the strongly draughting, aptly named Hedgehog Crawl - 235m of hands and knees crawling on 3cm long crystals. This terminates in a series of small chambers, not fully explored, but with big potential as a streamway was found cascading down an undescended 15m pitch with other leads still to be pushed.
    Back at the start of the decorated chambers, two more sections were entered - the Going Home series and Wonderland. The latter consists of approximately 700m of varying passage, extremely well decorated with a profusion of 50cm helicites, ending at boulders around which passage is visible - a days work should clear this choke. Going Home has a low beginning but ends in a Yorkshire-type streamway explored downstream past cascades to the head of an undescended pitch.

   Due to the expansion of Mostajo, more questions than ever remain to be answered in the Matienzo caving area, ensuring plentiful opportunities for equally major discoveries next year.