Matienzo Caves Project 2017

News and cave exploration around Matienzo during 2017.
A map with area names can be found here.

   Dr Peter Wynn from Lancaster University is planning the 3rd International Cave Monitoring Workshop to take place around Matienzo 20th - 23rd April. The overall theme of the workshop will be to develop a series of best practice protocols for monitoring the hydrology and meteorology of cave systems. Specific topics will cover data logging and instrumentation, high resolution drip water sampling, in-situ water chemical analysis, in-situ precipitation of carbonate and cave surveying. There is a website and a first circular. Anyone interested in participating in the workshop should contact Peter.
   Guy Simonnot (Spéléo-Club Dijon) has contributed surveys for Hoyo de Rotura and Cueva del Mar (with a description).

January & February

   The end of January saw photos taken in Cueva del Mar (0004), Cueva-Cubío de la Reñada (0048), Cuvia del Campo (0076) and the entrance to Cueva de Bollón (Volvo, site 0098). The Cueva de Carcavuezo area was visited: a small whirlpool was seen as one of the sinks and, although the overflow channel and entrance were completely clear of branches, the route into the cave at the base of the entrance climb was found to be choked.
   In February, a team on a walk from Alisas down to the bottom of the TV mast track, via Trillos and La Rasa, relocated a number of holes and found some possibly new undescended shafts. (Sites 1677, 1108, 1077, 1081, 1083, 1096, 4502, 4503)
   Surveys from the Christmas 2016 explorations by Simon Cornhill and Diane Arthurs in Torca de la Espina (0128) and Sprog on a Rock (0710) along with Torca del Hombre (3115) from early 2014 are now online. Phil Papard has scrutinized the separate surveys for the four caves of the Cubija (North Vega) System and produced a combined survey showing over 22km of cave passage.

  The list below shows links to those 19 sites which were extended or newly discovered over January & February 2016, or which have had surveys, references or descriptions updated, photos or movie clips added, or entrances repositioned with a GPS.

Alisas 1677 cave;
Cobadal 710 Sprog on a Rock; 3115 Hombre, Torca del;
Cubija 71 Mostajo, Torca del; 76 Campo, Cuvia del; 243 Cubija, Cubío de; 774 Morenuca, Cueva de la; 892 Regaton, Torca del;
La Rasa 1108 Cable, Torca del; 4502 shaft; 4503 shaft;
La Secada 81 Carcavuezo, Cueva de; 98 Bollón, Cueva de;
Muela 128 Espina, Torca de la;
Ogarrio 4 Mar, Cueva del;
S Vega 48 Reñada, Cueva-Cubío de la;
Trillos 1077 dig; 1081 shaft; 1083 shaft;

Juan Corrin, January, February 2017


   This year, Easter corresponded to a dry, sunny and warm fortnight in Matienzo! This was a real bonus for campers and the Latimer's extended family who were erecting a new roof on their new holiday home acquisition in La Vega. Just under 3km of new cave was found and surveyed, mainly in Cueva Fresnedo II (0841), Cueva-Cubío del Llanío (3234) and Fuente Aguanaz (0713). Eighty-seven new caves/sites were located and just under 700m of resurvey work was completed, mainly in the South Vega System where there is little modern survey data.
   Two diving projects took place. Rupert Skorupka continued the re-lining and pushing of the downstream sumps in Cueva Vallina (0733), but was hampered by poor visibility at times due to tourist cave traffic in the main Rio Rioja stream stirring up sediment. Due to this problem, the pushing of the dry passages above sump 6 was not pursued but will continue later in the year when diving is not taking place. The team of Jim Lister and Dan Hibberts worked in Invisible Cave (3283) where a short extension was abandoned as it was found to be both polluted and significantly silted up. The divers turned to the adjacent Fuente Aguanaz (0713) where they found a major extension beyond sump 1. One of the key primary objectives completed this Easter was to continue with the "Alto Asón" water tracing exercise. One key test was completed from El Cubillón (2538) with a positive test to Fuente Aguanaz (0713). This, and the new passage found in Aguanaz demonstrates the very large potential for this cave system.
   During the expedition, an International Cave Monitoring Workshop took place in Matienzo organised by Dr Peter Wynn of Lancaster University. Dr Wynn has had two PhD students working in our area at Cueva de Asiul (0061) and Cueva de las Perlas (0074). Paleoclimate records have been established, from selected stalagmites and cave monitoring, for key periods of human history including 40,000 years ago, when Homo Neanderthalensis disappeared. Andy Quin managed the logistics of the workshop greatly helped by the mayor of Matienzo and the loan of the old school building for the meetings. Various field excursions were made and members of the Matienzo Expedition helped out on some of these. The workshop attracted academics from institutions across Europe and as far away as the USA and SE Asia, and will have helped strengthen the knowledge of both Matienzo and the Alto Asón area as one of the key karst areas for such study.

Southern Sector
   At Cueva Vallina (0733), Rupert continued his diving work and all the sumps up to sump 6 were checked. It was found that the re-lining carried out last year was in good condition. However, the old line in sump 6 was found not to be in the best place and needed a new line placing. This was done up to the main inlet and connection with the dry extensions. However, what should have been some of the best visibility available due to the exceptional dry weather was ruined by silt from the Rio Rioja steamway caused by tourist cavers going to Vallina II as well as, to a lesser extent, Matienzo cavers travelling to the extension above the sumps. We stopped our work in the extensions to allow the water to clear, and the tourist caving group were also asked not to go into the steamway. However, some of the tourist group did not follow our request and made more trips, but did later agree to stop. It was noted in Reñada on a trip to sump 1 that, although the water in the main steam when first met was clear at the sump, cloudy water from Vallina was just beginning to come through. This issue caused a delay in the work and prevented a push beyond the inlet in sump 6. Gear was stored for a push later in the year. Only one trip went to the dry passages above sump 6 to begin to bolt across the traverse above the start of sump 6. More bolts are needed to complete this traverse.
   In Cueva-Cubío de la Reñada (0048), the lower passages of the South Vega System, the end of the route found last year at the west side of Stuffed Monk Passage was pushed over a traverse into 55m of new passage - side passages are still to be surveyed and pushed. In the Stuffed Monk area over 500m was re-surveyed as part of the South Vega System re-survey project. The possible by-pass to Sump 1 was dug to a small extension and surveyed (47m of new and previously unsurveyed passage) but the digging was difficult due to the very sticky clay needing each spade load to be pulled or scraped off. The passage is seen continuing low over the fill, but a lot of digging is needed. This site is worth a dig (tray left in) and a check should be made in good draughting weather. A high-level lead in the entrance series was investigated via a rigid extension ladder and bolting, but no significant passage was found. As part of the International Cave Monitoring Workshop members of the expedition took three delegates to Stuffed Monk Passage and Anastomoses Hall to look at cave geomorphology under Prof John Gunn's expert tuition.
   In South Vega, two new caves were found and pushed to chokes (4504 and 4506). The latter lies over the entrance passage in Reñada. Three undescended shafts (4508, 4509 and 4510) were located. A new small bedding cave (4519) was found draughting. The entrance needs digging out but it is possible to see on for about 5m. Eight known sites were checked out, five were found to be choked shafts (2260, 4199, 4167, 4197 and 4198). The first two were choked. Two - 1858 and 0853 - need more work (digging and a further drop to rig) to progress and one (1441) could not be found.
   At Seldesuto, the rock blocking the entrance to Torcón de la Calleja Rebollo (Toad in the Hole, site 0258) was removed. The draughting Root Tube Cave (4520) was extended by digging but more easy digging is needed. Nearby, a new site (4521) was found where rocks rattle down through boulders, but the site was not dug. Sites 1565 and 1566 could not be found, possibly due to location errors and site 1862 was found to have lots of dead animals dumped in it. Torca de Corcada (0780) was located and found to be still open and draughting.
   At Alisas, site 4364 was pushed 7m to a choked chamber; 4365 was found to 8m deep to a dig in boulders and site 1075 was pushed 25m to a choke. At Calzadillas a new hole (4511) was pushed 5m down a slope to a dig needing snappers. A nearby shaft (3638) was re-visited and pushed with the view to a possible connection with Toad in the Hole (0258) but, although a draughting small lead requiring opening up for at least 3m was found, no connection was made. The site needs a resurvey.
   Two known sites were visited on the slopes of North Vega: Cueva de Acebo (0433) was capped to get around a corner, but it was found too small beyond and site 0434 was re-surveyed to 143 m (an extra 68 m) but needs snappers to make more progress. A small resurgence (4590) was noted 150 SE of Fuente de las Colmenas (0363).
   On El Naso, the re-survey work at 415 continued, including dropping a pitch, but it was not clear whether it had been pushed previously. Work will continue on this project. Four new sites were located: 4505, 4512, 4513 and 4514. All need more work (descending and digging) to progress. Known sites 3138 and 2379 were pushed to chokes with little prospects. Sites 4022 and 2377 were found and pushed, but need capping to progress. Site 2375 was dropped 15m in two pitches to a choke with an aven above. Site 0496 was noted to have a warm draught indicating a likely near-by source.
   As part of the International Cave Monitoring Workshop, the traverse from Cueva Oñite (0027) to the Toca del Sedo entrance of the Sistema del Risco (0025) was made, again looking at cave geomorphology with Prof John Gunn.

The North-East Sector including The Four Valleys System
    In La Secada, despite flooding since last summer, the entrance to Cueva de Carcavuezo (0081) was found to be open and accessible for the summer expedition. In the area to the north and east of the "Mushroom Field" a number of sites were checked out and located with GPS as many old positions were estimated from maps, including sites 0869, 0870 and 0880. Sites 2709 and 1552 were located and confirmed they are not the same - new GPS readings were taken and both are worth a closer look and push. Site 1553 was GPS'ed but the old location was found to be correct. Site 0260 was re-explored - but this area needs looking at again in some detail. Nearby site 0252 was opened up and descended but needs capping to make progress - it draughts well. Five new sites were located: 4522 - 3m deep that could be dug; 4532 - a draughting hole that could be dug; 4507 - a 2m deep with no way on; Badger Hole (4535) - an old short remnant 4m deep with a fill floor and Two Way Cave (4534). This is an old remnant going both ways from a skylight entrance. It was surveyed to 26m with an easy dig in a side passage heading to the north which needs checking out in good draughting weather. The entrance to sites Cueva Seta (0093) and the nearby 1744 could not be found. They seem to have been filled in as the location should have been accurate given the nearby barn that is clearly marked on the map.
   Near the far end of Fresnedo II (0841) three pushing trips were made to the Block Chamber and the Rio Lastras Inlet area via The Howling. This required use of a scaling pole to get up a waterfall in poor rock. In total, 628m of important new passage was found in this area.
    A 13-year-old boy from Fresnedo told us about a "through-the-hill" cave he knew about. A meeting was arranged - and it turned out to be Cueva Fresnedo I (0126).
   In Cueva-Cubío del Llanío (3234), the Mitre Passage area was pushed in dry conditions - much better than last year. This resulted in a major breakthrough with 1056m of new passage found with leads still left to be examined. The Mulu Manners tunnel heads towards the passages to the west of the Road to Torno in Cueva de Riaño (0105)and, at the closest point, is about 100m away. At the start of this key extension, passages to the SW entered an area with tree roots and what appeared to be a small draughting hole near the surface. Ron Taylor's "Subphones" were used to locate this point and the depth was estimated to be about 6m to the floor at the molephone station, indicating that approximately 4 to 4.5m of digging was needed to the highest point seen in the cave. As the trip to this point is awkward and takes some 1.5 hours, a dig was started (site 4536 - Subphone Dig) and it is now a little over 2m deep following a channel in limestone which then dips vertically down forming walls on about a third of the dig, with clay/sandy fill forming the rest. A 1m drill inserted in the base seemed to hit either loose fill or a part void about 60cm down. This site will be dug in the summer and if successful will give a better entrance to this key extension and help to get a link to the Four Valleys System to bring it to well over 60km.
   Work continued to make the Giant Panda entrance (2691) to Cueva Hoyuca (0107) safe following the rock fall at the first pitch two winters ago and following the work done last summer. However, on close inspection, it was decided that, although the pitch top could be cleared, it looked quite possible that removing the large block adjacent to the rope hang could undermine the massive boulder that had moved down in the original collapse. To avoid working in this area it was realised that, at the bottom of the entrance, an easy dig would gain the pitch away from this boulder and would probably give safe access. Work was started to open up this dig and in doing so the original way down was blocked. So, for now, this entrance is not possible. In the summer, more work will be done on this new access route.
   In the Riaño area, five new sites were located: 4515 - 7m deep to dig; 4516 - 5m to a choke; 4517 - needing snappers to get down a shaft and 4541 and 4542 were found but not descended. Cueva Shelob (4173) was dug with an ongoing passage needing digging to get along a visible but small passage. On drawing up the extension in Cueva-Cubío del Llanío (3234) it is clear that it runs very close to Cueva Shelob and a connection seems possible. Site 4172 was pushed to 7m deep and 12m long but, with no draught, it was thought not to be a good prospect for more work.
   Fridge Door Cave (1800) was looked at but, despite the dry weather, it was flooded below the entrance pitch and so diving was left for the summer when water levels may be lower.

Solórzano and the Riolastras Area
No activity took place over Easter. Work to complete the survey in Cueva del Arroyo de Canastrillas (4046) and push the passage beyond the sump in Cueva de Lolo (del Secretario - 3991 was left for the summer expedition.

Northwest Sector
   As part of the water tracing work, 3 litres of optical brightening agent (OBA) were placed in the steamway at the downstream sump in El Cubillon (2538) on the 23rd April, with detectors downstream of the resurgences of Cave of the Wild Mare (0767), Fuente Aguanaz (0713) and La Riega (0551), the resurgence for the water in Cueva la Verde (4486). On 1st May (and subsequently) the detector at Fuente Aguanaz was positive. The other two sites were negative and remained negative when tested in the following weeks.
   At Hornedo, there was only one trip into Torca la Vaca (2889) via BigMat Calf Hole (3916), to the Mard Arse area. In the event, route finding was a problem and pushing was incomplete. Two new sites were located (4583 and 4584) and pushed to where digging is required. Site 3010 was found to be a 1.5m drop into a rift blocked at both ends.
   When looking for Cueva de Collada (0394) in La Gatuna, a new site, Eastwater Entrance (4537) was found that was explored down between boulders and into Cueva de Collada giving a much better entrance and an extra 49m of passage. This should help pushing this site which seems to be the origin of the Suit Wrecker Inlet and Friday the 13th Passage in the far SE of Torca la Vaca (2889).
   In San Antonio, Dan Hibberts and Jim Lister started diving work at Invisible Cave (3283) reaching sump 9 where gravel had to be dug out under water to allow access for further pushing. On the next trip, the sump was found to be closing down and the water smelt polluted. As both divers felt ill that evening pollution seemed to be confirmed. Attention was then diverted to Fuente Aguanaz (0713). This proved to be extremely profitable as, on the first of three trips past sump 1, an inlet was entered and followed for a considerable distance before reaching a sump. This short sump was dived on a second trip to more passage and a boulder choke where a hole could be looked through into what looked like a higher large passage, but this needed a lump hammer to remove rock to enter. The passage was surveyed for 770m up to the sump on a third trip, but there was no time to push further at Easter and work will continue in the summer.
   Seven new sites were located: a sink to the north of the main road (4565); a 3.5m deep shaft to a small chamber (4566); an undescended 3m shaft needing work to enter (4567); a small cave blocked by silt (4568); a 10m long rift ending in a choke (4569); a draughting blocked shaft that needs digging (4570) and a 3m shaft to sediment fill (4571). Site 3027 was dug and pushed to 12m with more work needed.
   At Garzón, Pipe Cave (4050) was pushed and surveyed to 140m of which 32m was new. Signs of flooding were noted.
   A lot of prospecting work took place at Composdelante, with 35 new sites located (4543 to 4564 (see list below for the links), 4573, 4574, 4577, 4578, 4579, 4580, 4581, 4582, 4585, 4586, 4587, 4588, 4589 and 4592). Just under half of them have some digging potential and 3 shafts were undescended needing work to enter. Of note were 4549 - pushed to 22m deep to a choke; 4553 - pushed to 21m deep to a dig; 4558 - explored to a shaft and tight squeeze with a further shaft and climb to a choke and 4573 - climbed down in a rift to a mud floor and on for 15m to a choke with a draught. Work to open or dig a number of these sites will continue. Dos Perros (2988) was checked and the sump level was found to have dropped to a pool with a passage continuing, but was too narrow to follow.
   In the hill behind the Church at Navajeda, two new sites were found: 4576 - a 3m long tube needing digging to make progress, and site 4575 - a 3m long cave to a dig with the passage continuing. Cueva de la Iglesia IV, as 4575 was later called, was dug over a few days and pushed into a complex area of phreatic eroded chambers with good formations, this was surveyed to 78m and photographed. Unlike the other "Church Caves" this did not seem to have any archaeological significance due, we assume, to the small entrance that needed digging and the use of snappers to enter!
   The following work was carried out in agreement with the Spanish club G. E. Pistruellos.
   In El Cubillón (2538) at Moncobe, the second pitch was re-rigged to remove a rub point and OBA was placed in the sump - later detected at Fuente Aguanaz, as discussed above. A lot of prospecting took place this Easter with 12 new sites located, of these five (4528, 4529, 4530, 4538 and 4539) require digging to gain significant cave; two (4524 and 4533) were pushed to fill blockage with no draught and no real prospect and two are undescended shafts (4526 and 4527). A lot of work went into pushing the new site 4525 including opening up a pitch to a chamber and then capping a draughting rift and surveying the find. But more work is needed and leads remain. Site 3669 was pushed 8m and is now 7m deep to a dig. Four days were spent digging in 4474 where two of three draughting leads were pushed after opening up the entrance pitch to get better access. One led to a further pitch (still to be pushed) and the second to a crawl which, after removal of an obstructing flake, led to more chambers and large passages ending in tight sections. Part of the cave was surveyed but more work and pushing is needed.
    At Ideopuerta, Torca de Hoyo Carabo (Washing Machine Hole, 3420) was opened up over two trips with a lot of digging to remove flood debris. The pitch needed some re-rigging and replacement of the rope. A traverse across the pitch to check the passage on far side was made, but no onward lead or further pitch found. The bottom of the cave still needs to be pushed but it requires two thin cavers to push safely. Four sites were checked out for future work: 3692 and 4483 are worth digging; 3655 was pushed through a tight section into a choked chamber and was not thought to be worth any more work. Although site 3693 draughts well, no way on could be found.
Visiting Revilla on a day off, a 4m long draughting cave to a choke was found in the left bank of the river. This site is out of our area of interest and the information (along with the finds in Moncobe and Ideopuerta) will be passed on to the G.E. Pistruellos club.
Easter expedition article by Phil Papard.
Survey updates
0048 Reñada complete (JC)
0394/4537 Collada new entrance complete (JC)
0434 cave complete (DB)
0713 Fuente Aguanaz complete (PP)
0733 Vallina complete (JC)
0841 Fresnedo 2 complete (JC)
2889 Torca la Vaca complete (JC) (use Chrome)
3234 Llanío (Cold Store) complete (JC)
4050 Pipe Cave in hand (PG)
4474 cave ?? in hand (AL??)
4506 cave complete (JC)
4525 cave ?? in hand (AL??)
4534 Two-way Cave complete (PP)
4575 Iglesia 4 complete (PP)

   The list below shows links to those 171 sites which were extended or newly discovered over April & May 2016, or which have had surveys, references or descriptions updated, photos or movie clips added, or entrances repositioned with a GPS.

Alisas 1075 shaft;
Arredondo 733 Vallina, Cueva;
Barrio de Arriba 4587 shaft; 4588 shaft; 4589 cave;
Bustablado 4364 shaft; 4365 shaft;
Camposdelante 2988 Dos Perros; 4543 cave; 4544 shaft; 4545 cave; 4546 cave; 4547 shaft; 4548 dig; 4549 shaft; 4550 shaft; 4551 shaft; 4552 cave; 4553 shaft; 4554 cave; 4555 shaft; 4556 cave; 4557 cave; 4558 shaft; 4559 shaft; 4560 shaft; 4561 shaft; 4562 shaft; 4563 shaft; 4564 shaft; 4573 rift; 4574 cave; 4577 cave; 4578 shaft; 4579 cave; 4580 shaft; 4581 cave; 4582 shaft; 4585 rift; 4586 cave; 4592 rift;
Cobadal 618 Orchard Cave;
El Naso 61 Asiul, Cueva de; 74 Perlas, Cueva de las; 496 Casasierra, Cubío de la; 1235 Roja, Cueva; 2375 shaft; 2377 shaft; 2379 shaft; 3138 shaft; 4022 shaft; 4505 shaft; 4512 cave; 4513 cave; 4514 hole;
El Sedo 25 Risco, Sima-Cueva del;
Fresnedo 126 Fresnedo 1, Cueva; 841 Fresnedo 2, Cueva;
Garzón, Solórzano 4050 Pipe Cave;
Hornedo 767 Wild Mare, Cave of the; 2889 Vaca, Torca La; 3010 cave; 3261 shaft & cave; 3282 resurgence; 4583 cave; 4584 cave;
Ideopuerta 3420 Hoyo Carabo, Torca de; 3692 dig;
La Cavada 551 Riega, La;
La Gatuna 394 Collada, Cueva de; 4537 Cueva Collada (entrada 2);
La Rasa 1096 cave;
La Secada 93 Seta, Cueva; 252 cave; 260 shaft; 415 cave; 869 cave; 870 shaft; 880 dig; 1552 dig; 1553 shaft; 1744 cave; 2709 shaft; 4507 shaft; 4522 dig; 4532 dig; 4534 Two-way Cave; 4535 Badger Hole;
Las Calzadillas 3638 shaft; 4511 cave; 4572 cave;
Moncobe 2538 Cubillón, El; 3655 shaft; 3669 caves; 3693 cave; 4474 shaft; 4483 dig; 4523 shaft; 4524 shaft; 4525 shaft; 4526 shaft; 4527 hole; 4528 cave; 4529 cave; 4530 dig; 4531 collapse; 4533 shaft; 4538 cave; 4539 sink;
N Vega 433 Acebo, Cueva de; 434 cave; 4590 resurgence; 4591 dig;
Navajeda 4420 Iglesia 2, Cueva de la; 4575 Iglesia 4, Cueva de la; 4576 cave;
Ozana 17 Jivero 2, Cueva de; 27 Oñite, Cueva; 376 cave;
Riaño 255 Via, Fuente de la; 2691 Giant Panda entrance; 3234 Llanío, Cueva-Cubío del; 4173 Shelob, Cueva; 4174 shaft; 4515 shaft; 4516 shaft; 4517 shaft; 4518 caves; 4536 Sub-phone dig; 4541 dig; 4542 shaft;
S Vega 48 Reñada, Cueva-Cubío de la; 331 shaft; 333 Azpilicueta, Torca de; 339 shaft; 407 cave; 675 shaft; 853 shaft; 1253 Dead Fox Passage; 1441 shaft; 1858 cave; 2260 shaft; 4167 shaft; 4197 shaft; 4198 hole; 4199 shaft; 4221 Reñada, Cueva-Cubío de la (top entrance); 4504 cave; 4506 cave; 4508 shaft; 4509 shaft; 4510 shaft; 4519 cave;
San Antonio 713 Aguanaz, Fuente; 3027 cave; 3283 Invisible Cave; 4565 sink; 4566 shaft; 4567 shaft; 4568 cave; 4569 rift; 4570 shaft; 4571 shaft;
Seldesuto 258 Calleja Rebollo, Torcón de la; 780 Corcada, Torca de; 1310 resurgence; 1565 dig; 1566 dig; 1862 cave; 4520 Root Tube Cave; 4521 dig;

Additional news
The document outlining water tracing work around the area (since the 1960s) has been updated to June 2017 and supplemented with a map showing the successful traces.