Cave exploration around Matienzo during Easter, Whit and Summer 1998

Juan Corrin, August 1998

    1998 was the 28th year of British caving expeditions to Matienzo (area map) and it proved somewhat disappointing on the speleological side. At Easter, about 1km of new passage was surveyed through very wet and cold weather and, in the summer, about the same amount of new passage was explored. A total passage length of 2038m was surveyed. Fewer people than usual (including only four Catalans) visited the area in the summer although over 120 different sites were discovered, extended or visited.

Nos	System	surveyed length	total metres
258	Toad	629	6195
733	Vallina	328	26054
33	Abono	196	318
73	Patatal	160	280
1289	cave	131	131
237	Bodegon	122	347
77	Rascavieja	83	533
1332	cave	83	83
1128	Vacuación	78	78
1325	Lammas	65	65
1294	Epiglottis Cavern	55	55
1295	cave	37	37
1333	Torca Tortilla	35	35
1271	cave	24	39
1292	cave	12	12
	Matienzo total	2038m
	Peña Jorao	490	8147

   Most new passage was explored in Toad in the Hole, where the draughting Baz's Choke was dug through in a couple of places and pushed into extensions totalling 583m. A further 46m was explored off Patrick's Silly Passage in Correspondent's Capers, about half way to the end of the cave. Toad is still proving difficult to push.

   Diving in Cueva Vallina at Easter, Martin Holroyd and Ross Greenwood discovered the true source of the water in the upstream sump 2. The passage continues underwater. In sump 3, another 50m was explored to a cross rift. In the summer, a muddy climb off Toc Gallery entered the Rope Climb Series, a muddy series of higher level passage which may still continue. Explorations in the New York Gallery suggested that this may be the best pushing area to achieve a link with the South Vega System. The Catalans explored 66m after climbing up 15m into the Resistance Gallery inlet. The length of Cueva Vallina is now 26054m. In the South Vega System, no new passage was discovered by bolting and climbing up in the final, China Syndrome Aven.
    Above and to the west of Vallina, close to Sima Cueto, lies Sima de la Garma de los Trillos. This hole, explored in the 80's by the Catalans, is 1.3km long and 340m deep, ending at the same altitude as the lower levels in Vallina. Nearby is Cueva Contrabandistas, a re-examined site which has a good draught and echo which encourages digging. Joint explorations with the Catalan cavers should occur in these last two sites next year. To the east of Vallina, Cuenca cavers are exploring large passages which must be part of the same system.
    In Cueva Abono, a high level cave above the South Vega System, a calcite dig at the bottom was excavated through into a nicely decorated false-floored phreatic passage (at about 440m altitude) and a breakdown chamber with choked pitches.
    At 375m altitude, site 1332 with a very strongly draughting entrance, was pushed through to a complicated set of pitches with one of 25m undescended. This site would appear to be very close to the East Wanders in Torca de la Vera Negra.
    In Cueva Arenal, the draughting rift was enlarged and pushed for a few metres to where it was possible to see that the draughting route appeared to be blocked with boulders.
   Torca de la Vacunación proved to be a difficult shaft to open up. A tight entrance passage, descending steeply to the head of a pitch, had two "floors" of boulders which were removed to provide a reasonably safe descent to a ledge and another pitch to a depth of 50m. From here a tight passage descends to a 4m climb down and the head of 8m and 10m undescended pitches. This site is perched over Cueva Vallina at 614m altitude.
    At a similar height, Torca Tortilla was explored down to 35m. A number of other small shafts were discovered and some explored over the Vallina-South Vega connection area, and the large and impressive Torca Reguilon was re-explored to the same jumble of moving car-sized blocks.
    To the east of any expected connection, Cueva Lammas (site 1325) proved to be an interesting pot with potential. Located just above the TV mast track, the entrance shakehole was excavated of some boulders and immediate entry gained to a 16m long chamber. At the far end a short climb down met a dribble of water and the top of an excavated section down through calcited boulders. A set of 4 ladders was strung down from this point, threading through a number of drops and squeezes to end at a short horizontal section some 40m down. Numerous attempts were made to enlarge the head of the following 10m pitch and eventually, at the base, another dig was encountered with a good echo. A strong draught moves down into the cave.
    At a higher altitude, in Cueva Codisera, bolting up to an interesting hole above Sima de las Chinas discovered an alcove.

   The Cantabrian Cultura authority has begun to gate some archaeological sites around Matienzo: to date these include Cobrantes, Emboscados, Cofresnedo and Sotarraña. On the day gating starting at Sotarraña, a resurvey of the cave was finished and the length set at 280m.
    Another site with archaeological interest is cave 1289, where the talus cone at the base of a tight 4m shaft (now bypassed through an excavated entrance crawl) contains a prehistoric broken pot in calcite awaiting excavation. The cave extends for 131m, with some nice formations, before choking a few metres from the roadside caves just above the new causeway.
   Cueva del Dientes, at the top of a steep fault feature, is a 5m diameter chamber where the initial stages of an official excavation have revealed some remains of at least two humans, one a juvenile.

   Extensions in El Bodegon, near the Secadura resurgence, included a small passage which came from half way along the cave back to and beyond the entrance, at a lower level.

   On the north side of La Vega some exploration was carried out in Rascavieja, where 83m was added to the length. A short distance to the east of Rascavieja, site 1271 descended in a tight rift for some 45m. Epiglottis Cavern was opened up and 55m of well decorated passage surveyed. Around El Naso, near the end of Cueva Molino, site 1295 started with a 4m pitch and was explored for 37m, closing down in both directions. Further north, above La Secada, Torca de la Cruz Llorada was pushed without success and lower down in an old stream bed, site 1300 descended down 2 pitches to close in at a depth of 20m.

   Above Cueva Hoyuca, where a large patch of eucalyptus trees had been felled, a number of small pots were descended. Near to Torcón, Cueva del Cuervo (La Cuevona), a spectacular 100m long gash enclosed in trees was walked into. The overhanging, 20m high cliffs at the northern end may have a completely choked passage. An inlet 7m up one wall was too small to follow.

   Other explorations included the exploration of Sima del Canado, some 17 years after being seen. Unfortunately, the shaft choked at a depth of 55m.

   During the summer, a couple of parties in the Covachos de Peña Jorao extended the length by 490m to reach 8147m.

   The total number of sites documented around the Matienzo depression has risen by 90 and is now 1349 with over 211.7km of explored cave passage. To date, no grants have been received from the Foundation for Sport and the Arts or the Sports Council.