Explorations in the caves around Matienzo during 1994

amended from an article by Juan Corrin in Caves & Caving 66

The Four Valleys System
   During 1993 the main thrust of exploration in the 40.6km long Four Valleys System was up the Astradome, a 30m diameter, 100m high aven, about 4.5km into La Hoyuca (site 107). It was to overcome poor bolting rock discovered 90m up during the previous year that Mark Wright and Alan Box took in a 6m aluminium sectional pole. This was erected from a bolt above the sandstone into the hole at the top of the aven. While returning from pushing above the aven, Alan fell 90m from a tail of rope. The recovery lasted 11 hours and involved 12 British and 11 Spanish cavers.

   Cueva de Bollón (98) was dived by Rob Murgatroyd and Toby Chilton to find 50m of passage and another sump. The potential is excellent with the end of the Western Series in Carcavueso (81) lurking a hundred metres away and virtually virgin limestone to the west, although Regaton (892) lies 1.5km in this direction.

El Sistema de Cubija
   In 1985 a pitch at the end of Hedgehog Crawl in Cueva Mostajo (71) was descended 40m by visiting Italian cavers and became too tight. Nine years later, after finds in Cubio-Regaton came very close, the Italian pitch was re-descended and the question mark became the link with Cubio-Regaton. Another 400m was surveyed at the end of Hedgehog Crawl. The combined Cubija System of El Cubio (243), Torca de Regaton and Torca de Mostajo now has a length of 14.2km. Further work should see other caves linked and a 20km system proved.
    Beneath the Cubija valley, on the north side of La Vega, Fuente el Escalón (280) was explored and joined to another nearby resurgence through 2.34km of small passage over a 70m vertical range.

Ozana
   The 8.3km in Risco (25) cave is highly linear and, although it lies under the edge of the Muela and Mullir, there is no known passage coming in from those hills. This year a bolt climb and traverse above the chasm at the southern end of the Arco Gallery found cavers ascending through a precarious boulder pile into a top level 50 - 60m above the stream. The passages discovered lie beyond and over the Arco Gallery on the same line and contain some impressive crystals and formations. One formation was described as a 1m high, single-crystal, triangular stalagmite, possibly re-crystallized and certainly rare. Nearly 800m were surveyed with a possible bolt climb still to go at, although there is still no sign of water or passage from Mullir.

South Vega
   The main pitch in Codisera (39) was crossed over to the east and a single shaft descended 90m to a floor of boulders with a soak-away. Part way down this pitch a major level was entered to the north but this choked with boulders after 80m. The continuation on the southern side of the wide shaft was bolted into and 230m of large, new passage entered. Unfortunately this tunnel and the higher level heading south both appear to choke under the head of a large, enclosed valley, near a point molephoned and GPS'd this summer.

Camargo
   Speleological activities carried out jointly with the Spanish GEIC/R group have occurred in Peña Jorao over a number of years. The system lies a short drive from Santander and takes water from a major sink and probably others within an area of archaeological importance. The site was extended by 2.3km to 7.14km.

Giles Barker
   Giles Barker died in the South Vega System during the 1992 expedition. At the suggestion of a local councillor the district council placed a plaque at the bottom entrance to the cave. A dedication ceremony with short speeches took place on Sunday, 14th August and was attended by members of this year's expedition and more than sixty villagers, including the Mayor and councillors. In all, well over one hundred people were present.

Recent References
Matienzo '93 in Caves & Caving 63, Spring 1994;
Matienzo '92 in Caves & Caving 58, Winter 1992