Matienzo 2001

Cave exploration around Matienzo during Easter, Whit, Summer and Christmas 2001

With the Foot & Mouth outbreak in the UK it was expected that a large group of cavers would converge on Matienzo to enjoy unrestricted access to the hills and caves at Easter. More than 60 people turned up, including 40 cavers with a number of first-timers, and the campsite was crowded. The weather was cloudy and cold for most of the time with a couple of days rain over the fortnight. More than 1.6km of passages were surveyed, the longest length of nearly 500m in site 1332, Cueva de Juan Lombrero. Martin Holroyd extended the upstream sump in Cueva Vallina by 200m and another 192m of higher level passage were also surveyed.
Fewer cavers came out for the very dry summer, but another 1.8km was explored. The highlights of the July / August visit included linking site 1338 with Coteron, the opening up of Hidden Hole to over 700m and the still-going explorations in site 408, Cueva de los Helechales. The number of sites of speleological interest increased by 108, giving a total of 1715 with over 227km of cave passage explored.
The summary highlights of our 31st year in Matienzo, described within the various cave areas, are as follows.

Four Valleys System
At Easter, the sump in Ovlov Passage in Carcavueso was dived into a descending 15m rift chamber with a narrow squeeze. This was pushed through in August into a wide passage with smooth walls, gravel bottom and zero belay points. Mark Smith was only on one bottle so, after about 30m, he returned with passage still wide open. The passage takes a good flow of water in flood and is further into the hill than the Cueva Bollón passages, still heading west. At the eastern end of Carcavueso, small passages were surveyed below Rhinocerus Passage, near Andy Quin's Foot.
In Cueva Bollón, entered through the Hole in the Road (site 1452), the passage heading west near the base of the 1452 slope was explored during a very dry period in the summer. A descent of about 10m lands at the edge of a shallow pool and solid passage can be followed for only 10m before the route is filled with unstable boulders. The next 50 or so metres requires weaving between boulders and ends at a draughting dig.
Bits and pieces were looked at around the Mushroom Field and generally in that area. Site 1671,  a draughting, wet weather resurgence was dug out but requires further work to proceed. The draughting sites 1680, 1681 and 1682 were documented for future investigation.
Some resurveying was carried out in Hoyuca to better show the depths in and beyond the entrance series.
The surface above passages leading to the Astradome in Hoyuca was investigated, revealing water sinking in a high level depression and a number of interesting sites. The sink (site 1618) was cleared of a couple of boulders to expose a short crawl into 30m of walking size passage that choked in two directions. The water feeding the depression comes from 2 caves: site 1617 is hands-and-knees for 20m to a split where the passage continues beyond a diggable section; site 1666 has been explored for 30m and continues. Sites 1667, 1670, 1672 are all draughting holes that may yield to further digging.
In Riaño, a few metres southeast of the entrance to Cueva Riaño, the Mad Axe Woman Cave (site 1630) was dug out at Easter, Whit and summer and an arch can be seen ahead. The 30m long cave still holds some promise as a quicker route to the inner reaches of Riaño. Site 1496, 100m up the hill from the main Hoyuca entrance, was dug further but much more is required.
The length of the 4 Valleys System is now 42951m.
Above Hoyuca, at Fuente las Varas, the sink at the road side (Fuente las Varas Cave, site 104) was tested to a small resurgence (1614) some 30m below. It had been thought that the sink may have been the source of the water for the Astradome in Hoyuca or the water flowing from Cueva de la Canal (101). When it was clear that the water in Canal had an unknown source, the cave was re-explored and surveyed but no further progress was made at the flat-out end. The water flowing out of the FLV cave resurgence was followed down the hillside to an open, wet pitch and possible passage (site 1615) that turned out to be a wet dig in a rift.
Above Trident Passages in Hoyuca, on the hillsides north and east of  the Carcavueso sink, a number of sites were discovered or re-visited. For example, site 348 was rediscovered after a fire and the nearby small rift caves 1610, 1611, 1612 and 1613 documented; site 869 was surveyed and, a surprise, site 1623 - an 18m fragment of walking-sized phreatic passage - was discovered. Sites 1636, 1637, 1638, 1639, 1646, 1647, 1648, 1649 and site 1650 - all along the base of a thin sandstone bed - remain to be explored.

North Vega and El Naso
In Simas del Picon, a climb up an aven closed in.
In cave 415, an old series of "lost" pitches near the end of the cave were finally revisited and polished off. The 4 awkward and muddy drops descended some 60m, with a 15m free climb at the end to finish at -69m, the deepest section of the cave at an altitude of 197m.
The intriguing "415 corner" received attention with various digs being attacked, some to a conclusion: Preying Mantis Pot reached a depth of 27m with 2 pitches ending at a 30mm slot; site 1483 became too tight after one body length; Pants (site 1655) was worked at over 4 days with more excavating required and the draughting Victor's Dig (site 1697) was left as a mess of boulders against a possible solid wall.
The water trough shakehole dig on El Naso was pushed into a 6m chamber. Small shafts towards Cruz Llorada 1633, 1634 and 1635 were explored.
In Fuente Aguanaz, the major resurgence some 5km away to the northwest, "the inlet on the left" after the second sump was pushed at Easter. The passage continues tight through a few short climbs. A small chamber leads to a larger one with mud and boulder walls. and a stream enters through the ceiling. The third sump was pushed through small passage to an airbell and another small hole which could be passable with smaller bottles. This was pushed for 5m in the summer, where it became too tight, although "running water could be heard from the rockfall above".
Spanish archaeologists have permission to excavate in Cofresnedo. The cave is revealing animal bones, human remains and artifacts at a number of places. The archaologists are concentrating at spots within sight of daylight. Even picking into thin layers of sediment from the walls at the entrance have revealed mussel shells.
Pieces of a large, Iron Age pottery container was removed from La Cuvia de la Vega (site 360) after being discovered in March and can be seen here after rebuilding (although the base is completely missing).

Ozana & Muela
A few holes were "ticked off" on Muela at Easter but nothing exciting or promising was discovered. See sites 807, 808, 809 and 810. In the summer, site 858 was excavated for a number of days in an attempt to dig out the entrance. In the Ozana area, site 1640 was dug to reveal 20m of filled phreatic passage and, nearer to Codisera, site 1641 was descended 7m to a choke

South Vega, Seldesuto and the Trillos area
Sima de la Piluca (site 472) was re-explored, surveyed and extended in the small streamway. Various draughting sites in the cave could be dug. The system is 314m long and 141m deep.
During Easter, Whit and the summer, Cueva Cefrales was resurveyed and extended down a 16m deep pit. This 500m long fragment could be the key to opening up an area relatively devoid of passage. The passages above water in the resurgence Comellantes were resurveyed and the documented length increased from 440 to 672m. This included an extension at the western end where an enlarged rift entered 5m high chambers and passages. Interesting features included a stoney choke just below the surface and Spanish names on the walls, dated 2001! Some ancient pottery has been found on the sloping wall of the entrance passage.
More tying up of loose ends occurred in Reñada where passages between Ghost Lake and sump 1 were resurveyed to obtain the z coordinates. Coincidentally, 135m of "new" passage was surveyed and more passage was pushed and surveyed beyond Ghost Lake in October and at the end of the year.
Martin Holroyd continued his dive in upstream Cueva Vallina, pushing through smaller rifts and silty passage for 200 extra metres. The route continues in similar fashion. A high level extension - Climb on Big Junction Series - was explored through small passage for some 190m, and a nearby draughting boulder choke was declared a major project for the future. In the summer a small extension was made between boulders near Who Knows Where chamber that appears to continue up.
In Cueva de Juan Lombrero, the western end of the cave was pushed, near the start of the final chamber, down a 126m broken pitch. At the base, water entered a tight 3m high rift which could be seen to enlarge but becomes smaller again. At the top of the 126m pitch, new passage headed east into the Good Friday the 13th Extensions. The passage is varied going over some undescended holes and muddy climbs to a small phreatic "Sanatogen-type" passage. The orignal end was excavated and the passage entered required digging in 2 more places until Stop and Go Series finally ended at a bedding some 5 or 6cm high. This would appear to be very close to Hammered and Hidden Holes.
Hidden Hole was finally opened up at a very narrow pitch head. The drop of 57m entered big passage which is well decorated in places. There are a number of spots still to push including 20m and 50m pitches and a good dig. Hidden Hole reached a length of 711m and 118m deep. The lower passages are at the same altitude as Cefrales but about 100m away.
In site 1338, a couple of drops were descended in the Sentinel Chamber to take the depth to -172m. The cave was detackled early on at Easter, even though it was described as "wide open and still going". This optimism was well founded as the second trip in the summer connected the cave into the South Vega System at the Edge of the Universe and part way down the '81 Depths series.
At Easter, in Torca de Papá Noel, a crawl at the end was pushed to a rift (Polyp Passage) and beyond, a 10m undescended draughting pitch with a high level visible across. The area around BBQ at Saucepan Street was looked at again where a possible way on involves a 20m bolt route. None of the pitches were descended but they appear clean-washed and narrow at the bottom. A dig in Snow Bat Passage was attempted but it appears to be a long term effort.
Site 408, Cueva de los Helechales, was a focus throughout the year. The cave had been quickly explored down 2 pitches in 1982. The entrance was "rediscovered" at Easter and a pile of 2000 - 3000 year old pottery found on a ledge to one side. The warm draught invited re-exploration and this was carried out at Whit giving a surveyed length of 99m and a depth of 22m. A floor-less tube over the top of the first 10m pitch was also bolted to, but choked. In the summer, apparent passage across the first pitch was entered by climbing part way down and then using the scaling pole to reach the opposite side. This lead immediately to a traverse over 2 pits, the base of the second was later entered through site 1679. The walking passage then met pitches of 10m and 16m and finally a 4m pitch to the superb Hoedown Shaft, pitches of 30m and 58m. At the base of this, a tight section of meanders leads to an unexplored pitch of 40m. The cave is over the Codisera Arm in Coteron and is presently heading into the unknown. Other new sites in the area include 1657, 1658 and 1659.
In December, Cueva Cumpleaños (over the western side of the Renada entrance series, and entered once in 1983) was re-explored and photographed. Also during the Christmas period new sites 1708, 1709, 1710, 1711, 1712, 1713, 1714 and 1715 remain unexplored or are digs in interesting positions.
Newly explored smaller sites on the south side of La Vega include 1219, 1624, 1625, 1629. 1632, 1651, 1652, 1656 (where old antlers were found), 1658, 1659, 1662, 1663, 1664, 1675, 1683, 1687, 1688, 1691, 1692, 1693, 1694, 1698 and 1699. A number of these are above the northern limit of Vallina.
In the hunt for yet more holes in this limestone cheese, various digs had various amounts of effort expended on them: 1386 was deemed long term and filled in again; site 1390 (the twin stream sink) was dug on a couple of occasions and is still worthwhile; the Volcano with its warm draught was attacked on at least five days in the year and was surveyed to 35m with depth of 11m; site 1392 was choked; 1685 requires more digging.
In the Seldesuto area, the left hand passages in Cueva Arenal were resurveyed at Whit. This showed that the digs at the southern end are worth pursuing despite the Foam Dome extensions.
At Trillos, site 1665 was explored down a 25m pitch to a choke.and a couple of other sites remain unexplored. At Alisas, a number of sites were positioned correctly with a GPS and the small sites 1083, 1085 and 1086 explored.
The South Vega System should see a flurry of connections as more caves are joined. The table below summaries the present connections and the projected links that could increase the SVS length from 26.1km to over 30km, with 13 entrances. (All this is without the big one - a link through to Vallina would add 26.7km).

Once again, there were more questions raised for next year than were answered during 2001.
Frank Addis, who photographed a number of the Matienzo caves more than 20 years ago, has made his collection of about 450 colour slides available for scanning. These pictures are slowly being added to the cave description pages of the web site, e.g. helium ballooning in the Astradome and pictures from Solviejo.

In September 2001, The Archaeology of the Matienzo Depression North Spain was published as a British Archaeological Report*. This large volume details the mainly subterranean discoveries from the Upper Palaeolithic through to the Civil War, with many line drawings, photos and surveys. A number of Spanish experts have contributed to the work, putting many of the artefacts and other remains into a regional context. Chapters include reports on the excavated sites, e.g. Cubío Redondo: a Mesolithic land snail shell-midden and Sima del Diente: a Late Bronze Age Burial Cave and thematic studies about Palaeoloithic cave art, schematic-abstract art, ground stone implements, storage urns, pre-roman ard-shares and observations on protohistoric metal working in Cantabria.
(*The Archaeology of the Matienzo Depression by Jesus Ruiz Cobo and Peter Smith. BAR S975. ISBN 1 84171 183 7. A4 format, 224 pages. Published by John and Erica Hedges Ltd, British Archaeological Reports, 7 Longworth Road, Oxford OX2 6RA, England. Obtainable from Hadrian Books, 122 Banbury Road, Oxford OX2 7BP, England. £45. plus P&P.
bar@hadrianbooks.co.uk )

We were welcomed by Pablo at Bar German and the expedition is grateful for the camping facilities and the use of the restaurant for computing and drawing up. The expeditions were granted £600 from UK Sport after a recommendation from the Ghar Parau Foundation.

0016 Jivero 1, Cueva de; 0017 Jivero 2, Cueva de; 0042 Cefrales, Cueva de los; 0075 Picón, Simas del;
0081 Carcavuezo, Cueva de; 0101 Canal, Cueva de la; 0104 Fuente las Varas, Cueva de; 0107 Hoyuca, Cueva;
0219 cave; 0220 cave; 0221 cave; 0348 cave; 0352 shaft; 0360 Cuvia de la Vega, La; 0408 shaft;  0415 cave;
 0472 Piluca, Sima de la;  0501 Cerro Chico, Cueva del;  0519 shaft;  0585 cave;  0586 shaft;  0592 shaft;
 0593 shaft;  0636 shaft;  0707 shaft;  0713 Aguanaz, Fuente;  0733 Vallina, Cueva;  0807 shaft;  0808 shaft;
 0809 shaft;  0810 shaft;  0841 Fresnedo 2, Cueva;  0869 cave;  0880 dig;  1014 shaft; 1074 shaft; 1077 dig;
1078 shaft; 1079 shaft;  1080 shaft;  1081 shaft;  1082 shaft;  1083 shaft;  1084 shaft;  1085 cave;  1086 cave;
 1169 shaft;  1332 Juan Lombrero, Cueva de;  1338 shaft;  1391 cave;  1392 cave;  1471 Papá Noel, Torca de;
 1483 dig;  1506 cave;  1594 dig;  1600 shaft;  1601 depression;  1608 shaft;  1609 shaft;  1610 cave;
 1611 cave;  1612 cave;  1613 shaft;  1614 cave;  1615 cave;  1616 dig;  1617 cave;  1618 dig;  1619 cave;
 1620 dig;  1621 shaft;  1622 shaft;  1623 cave;  1624 shaft;  1625 shaft;  1626 cave;  1627 dig;  1628 dig;
 1629 shaft;  1630 cave;  1631 dig;  1632 cave;  1633 shaft;  1634 shaft;  1635 shaft;  1636 shaft;  1637 dig;
 1638 shaft;  1639 shaft;  1640 cave;  1641 shaft;  1642 shaft;  1643 cave;  1644 shaft;  1645 shaft;  1646 shaft;
 1647 dig;  1648 shaft;  1649 shaft;  1650 cave;  1651 shaft;  1652 shaft;  1653 cave;  1654 shaft;  1655 dig;
 1656 cave;  1657 shaft;  1658 shaft;  1659 cave.

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