News and cave exploration around Matienzo during 2015
A map with area names can be found here.

   To start the year, some details of a couple of archaeological caves at Navajeda (sites 4111 and 4112 survgeyed by GEIS C/R*), a number of grid reference updates and a new site on the northern side of La Vega (site 4113) - all supplied by Pete Smith.
   In February, after days of flooding followed by snow to low level, a small team took stal core samples (with permission) from Cueva de la Perlas, continuing the paleo-climate work in Cueva Asiul. (Video). (A blog post by Laura Deeprose outlines the project.) Site 4114 was also discovered on El Naso - a small cave with a dig at the back.
   A video by Ian Chandler of the flooding around the main road at the end of January can be seen on YouTube, and a photo of the flood by Pete Smith at the northern end of the depression can be seen here.
[* Grupo de Espeleología e Investigaciones Subterráneas Carballo/Rada]

  The list below shows links to those 10 sites which were extended or newly discovered over January & February 2015, or which have had surveys, references or descriptions updated, entrance photos or movie clips added, or entrances repositioned with a GPS.

Arredondo 43 Escarabajo, Cueva de; 733 Vallina, Cueva; 1004 cave;
El Naso 74 Perlas, Cueva de las; 4114 cave;
N Vega 4113 cave;
Navajeda 4111 Murciélagos, Cueva de los; 4112 Cuesta de la Encina, Cueva de la;
S Vega 687 Acebo, Torca de; 1175 Pino, Cueva del;

Juan Corrin, January, February, December 2015; January 2016

   Following the wettest winter in Northern Spain for decades, with the highest flooding in Matienzo since before the 1950’s, the Easter expedition started with high cave water levels. However, the pattern of weather changed and over the main expedition period there was very little rain with the temperature rising steadily, reaching almost 30C at one point, and the trees finally beginning to come into leaf.
   About forty people took part in the Easter expedition. Over 1,900m of new cave were surveyed, some 40 new caves/sites located, with over 700m surveyed in Cueva-Cubío de la Reñada, continuing the major resurvey of the part of the cave survey that dates from the early 1970’s. Due to a family bereavement a number of key members of the expedition, including Juan, had to leave early. Also, due to the cancellation of Brittany Ferry’s economy ferry a number of members had to rearrange bookings and lost a number of days in Matienzo. The result was that a large number of Expedition members were out for only about eight days – a little less than in previous years.
   One of the primary objectives completed this Easter was to start the major “Alto Asón” water tracing exercise with the Cueva Vallina test. Four litres of Leucophor were placed in the stream just upstream of the confluence of the waters from Vallina I and II. Detectors were placed in Cueva del Comellantes (40), Cueva del Molino (resurgence) (791), Fuente de Barcena Morel (3278) and the Bustablado river just down stream of the main resurgences on the south side opposite Molino. Detectors were also placed in Cueva-Cubío de la Reñada (48), at Sump 1, Squirrel's Passage and the stream below Castle Hall. After 8 days of negative detectors we were just beginning to think we may have not used enough Leucophor when the detector in Cueva del Comellantes went strongly positive. Subsequent checks on the other detectors showed them all to be negative apart from Sump 1 in Reñada which was also strongly positive. This test confirms that Vallina and Reñada are part of the same system, and that Squirrel's Passage water is an inlet and not part of the main river that flows out of Reñada II and into Reñada I via sump I. This result now gives us added incentive to push the two systems and possible surface links to realise this 100+km potential system.
   Another primary objective was to push site 2889, Torca la Vaca via the new entrance at BigMat Calf Hole (3916). So it was with great expectation that a team set out to find, explore and survey new cave – only to find the linking crawl had disappeared beneath a collapse! It seems that since the explorations over the Christmas period the extreme wet weather had again done its work and turned the usually hard sandy infill into soft slurry. This resulted in movement of the scaffold cage and complete infill of the linking crawl. Over the next two days the crawl was dug out and temporary shoring placed above the crawl – but more permanent work is needed urgently over the summer if we are to avoid a repeat in the next wet winter. Due to the short main expedition period and the need to re-dig this entrance, it restricted the time available to push the system, but despite this some 557m of new passages were surveyed, mainly in the central area.
   Partly as a result of the delay in getting into Vaca, the area above BigMat Calf Hole was looked at and a draughting hole located. This proved an easy dig and over the next week this “maze type” Cueva del Ciervo (4117) with many bear bones and pits was pushed to 458m and then linked to The Langdales giving a 491m system which lies a tantalising 35m above Vaca.
   Another major exploit was pushing Not Too Bad Pot (2964), via a major capping (100+ holes) exercise at the top of each of a series of tight pitches over four long trips. This work extended the cave to over 200m deep with a further tight rift needing yet more capping. This cave lies on the north side of the ridge to the east of the col at Cruz Usaño and may drain either to the Ogarrio area or into the Risco catchment. There is a small draught in the cave which needs checking in the summer (when it is hot both at night and during the day). If there is a strong draught, it will encourage further work.
   Other significant work was also carried out. In Cueva-Cubío de la Reñada 521m of previously unsurveyed (with some new) passage while resurveying the entrance series (up to the duck and near the Zepplin Hangers). Two new Dads, while babysitting, pushed their tame “ferret” into site 4046 (a resurgence in the Solórzano area) only to find it went. Their wives returned from a Vallina through trip to oversee and manage the exploration and survey of the 114m long Cueva del Arroyo de Canastrillas (Daddy Day Care Centre).

Southern Sector
    A SEDECK (La Sociedad Española de Espeleología y Ciencias del Karst) Conference, dealing with the long caves of the Alto Asón area, was held in Ramales de la Victoria last September. At this event it was decided that the various caving groups, including the Matienzo Caves Project team, would join forces to try and sort out the hydrology of this important area with water tracing. To prove the equipment and technique, a test using Leucophor was made at site 3886 with detectors in site 3884 and Cueva de Jivero 1 (16). As expected, the latter went positive and 3884 remained negative, so proving our technique.
   A successful test was carried out from Cueva Vallina to sump 1 in Cueva-Cubío de la Reñada and then to Cueva del Comellantes without going through Squirrel's Passage (see above). Further tests will be carried out in the summer if water levels are suitable, but the test programme is still to be finalised. In Cueva Vallina, while a group placed the Leucophor into the Rio de Rioja near sump 1, a resurvey of the passage from Big Junction to Double Dutch Pitch was carried out with more detail including left/right/up/down data.
   As noted above, the resurvey of Cueva-Cubío de la Reñada was completed up to the duck just past the rope climb down. A number of previously unsurveyed passages were found, mainly in the area just past the Blow Hole. Also a passage and climb were explored from the bottom of the 5m drop at the end of the passage where there is a climb up to the rope pitch to the duck – it ended at a choke where the new survey says “sound of frogs heard”! One aim was to resurvey the Zeppelin Hangers area. This was not done due to finding the area more complicated than on the old survey – it needs more work to identify the correct locations.
    Peter Smith continued his work over the winter locating and fixing cave entrances. On North Vega, cave 4113 was found and at Easter below the entrance climb the top of the next drop was bolted and a descent made to narrow rift 2m long with a good draught. Capping is now needed about 20m down to make further progress. A further 5 shafts were located in the area near site 0812 these were 4161, 4162, 4163, 4164 and 4165. The last three have a draught and are worth a dig while 4162 is covered with slabs and is undescended.
   The archaeological discoveries in site 3153, and the subsequent anthropological study by the Aranzadi Science Society (San Sebastián), has identified a minimum number of five adult individuals and one child.
   A key push in this area was at Not Too Bad Pot (2964), to the east of Cruz Usaño, where a massive capping exercise (see above) over four trips pushed this shaft down a series of pitches to a further section needing capping at about 200m depth.
   Cueva de Coreano (137) was visited to push the wet section but was found to be flooded. This needs looking at in dry weather. Site 1033 high above site 137 was looked at, confirming it is a good dig but needs a lot of work.
   In Simas del Picón (75), the Picón Eye Series was pushed to a 10m pitch through a squeeze to a rift passage with use of capping. Snappers are needed to make more progress. To the southeast of Picón, site 4130 - a small 6m cave with a draught - was found. This needs digging to make further progress.
   At Alisas, a number of new sites 4120, 4121, 4122, 4123, 4124 and 4125 were located with one 22.5m deep shaft (4123) needing more tackle to get to the floor and a possible second drop/dig that can be seen from the bottom of the two ladders available.
   A little further to the north, at Las Calzadillas, shaft 4133 was opened up and a false floor removed to give a 16m drop, making it 18m deep but choked. Site 4119 was a twin hole but with no real prospect and, at site 4134, four small caves were located below the Alisas road, again with not a lot of prospects for extension. The entrance to site 2502 was opened up and found to to be 3m long with boulders at the end and a narrow descending 3m deep rift needing more work. Site 3815 dropped 3m with no way on. Site 1973, an 8m shaft to a rubbish-covered floor, was extended with a small chamber, inlet passage and a 2m deep clean washed rift which closed down. To the east of the Alisas road, near the head of the Arroyo Revilla, shafts 3759 and 3760 were descended. Site 3759 was found to be 20m long and 8m deep to a draughting slot, while 3760 is similar but does not connect and is choked at 13m depth.

The Northeast Sector and The Four Valleys System
    At Cueva de Carcavuezo (81), the entrance was found to be open despite being almost blocked by logs following the winter floods. Other sinks in the area that are known to go into the entrance series were full of debris with no draught. The normal entrance was measured for a grid which, if fitted, should stop logs and the odd calf being washed in.
   Opposite the entrance, on the far bank of the overflow channel, a large collapse has occurred but with no open hole currently present. A number of small shafts (4126, 4127, 4128 and 4129) on the edge of a cliff line to the northwest of the entrance were looked at. All were found choked at between 3 and 8m deep. Site 4045, next to the track near the normal entrance, was dug to a choke. The entrance was walled up including a “body board” that had been washed into the area. The nearby site 4016 was also dug, but seems to be a slip feature rather than a water-formed cave.
   The usual river sink area was later surveyed and the 7 places where water usually disappears plotted out and tied into permanent surface survey stations. The 1980's survey of the underground stream passage lines up well with the sinks above. In the summer it will be important to radio locate the Green Cool Passage in the Western Series as it may be possible to dig into this from the river sink, improving the depression drainage and so reduce flooding risks. The excavation work would be for the village to arrange with our help as needed.
   Cueva de los Tres Niños (565) was looked at and possible leads identified, but more work is required. Now with a good grid reference, the site can be more easily found. In the flatter area below Tres Niños, two new sites were identified, a small cave 4115 and a new collapse and sink 4116.
   In a difficult-to-traverse jungle area above the “mushroom field”, the “sandstone dig”, site 4132 - the radio location point for the northern of Trident Series in Cueva Hoyuca (107) - was located. This was dug to several metres deep in the 1980’s but was backfilled as it was on a track. In a shallow gully to the south, a small draughting cave (4131) was found. The location and some digging showed it to be a promising site for a further work with a small draught and a solid arched roof. A check of the draught in warm weather is needed and a day’s digging will show if it is worthwhile.
   The Giant Panda Entrance (2691) to Cueva Hoyuca was found to need stabilising as the wooden pallets have now almost rotted through. More worrying were signs of movement inside, resulting in a large boulder falling over the top of the first pitch blocking the way on. Work will be needed in the summer to both sort out the entrance and to remove the boulder and stabilise the area.
   In Cueva Hoyuca a visit to Tilers' Way in the entrance series was made and the water lowered, but it still requires more work. Twenty four metres of new cave were surveyed. Site 718 was checked and this looks like a good prospect for a new entrance to the system.
    In Cueva Llanío (3234), the Horny Dog area was checked out and a rift dropped to a mud choke, but no significant passage was found. One lead has a pool that needs to be removed to make progress, an attempt to pump out the pool was not successful with the equipment available.

Solórzano and Riolastras Area
   Little work was done at Easter in this area. Just five new sites were located in the Riolastras area: 4138 and 4142 are worth digging, the latter having a small draught; 4141 is an undescended 6m deep shaft and the other two sites, 4139 and 4140, had no draught and little prospect.

Northwest Sector
   The water levels over the Easter week were still too high after the winter rain to attempt work in Washing Machine Hole (3420). Cueva de Los Campizos (YoYo Cave) (3812) was descended to look at the series of pitches in a rift off the bottom chamber. Just before the rift gets too tight an 8m climb lead to wider passage and a climb/pitch down to a chamber with a narrow outlet (too small for many metres). However, a 20m climb led to a further passage and a drop down with some water entering on the far wall – this pitch is still to be descended. This needs be looked at in the summer as the pitches in the cave were left rigged.
   In the Navajeda area, 250m to the NW of Famous Five Cave (1072), three new caves were found: 4144, 4145 and 4146. The latter two closed down after about 8-9m, but 4144 has a partially walled entrance leading to a complex of interconnecting passages estimated at about 100m length, still to be surveyed. Site 4112, Cueva de la Cuesta de la Encina, was later surveyed to 211m, increasing the length of the archaological site by about 20m, with possible places for extension.
   Mina Favorita (1561), which lies to the north of the Alisas road at Barrio de Arriba, was checked out as it was known the mine worked some natural cavities for the zinc blende. Two natural rifts were bolted, but no way on was found.
   In Cobadal, cave 4137 was found on the edge of very large depression with a strong outward draught. The cave slopes down to a chamber and a further descent where it became too tight. It needs work to locate the source of the draught and possible dig. Nearby, a choked 2.5m deep rift, site 4243, was recorded.
   At the side of a track above the far reaches of Fuente Aguanaz a small, 3m deep hole (4136) was found. It requires serious digging to make progress.
   In Hornedo, between Cave of the Wild Mare (767) and Peña Encaramada (3380), site 2942 was dug to reveal a 6m deep rift with the floor blocked by sandstone boulders and daylight visible above a slope opposite the entrance. The nearby 2947 was opened up and is 5m deep to a 5m long rift, closing down at the northern end with daylight visible (possibly from site 2920). The southern end is a narrowing rift that needs capping, with a possible enlargement after 3m. Also found adjacent to this site were six small, tight, entrances south along the same scar.
   A surface prospecting day from the parking area for BigMat Calf Hole up to La Collada and into the western slope of La Gatuna found 11 leads numbered 4147 to 4157 (all links below). None were pushed to any length, but several warrant further investigations. A further three digs/sites - Pallet Hole (4118), 4158 and 4159 - were found near the parking area and 4160 was found to the west of BigMat Calf Hole. None had open leads and at Easter they had little or no draught. Digging is needed to make progress, but checking for draught in warm weather should help to prioritise prospects. In the north side of the Arroyo de Entrambasaguas valley an obvious cave (4135) was seen from a distance away near the main road. This “cave” was examined and found to be an undercut in sandstone beds.
   While BigMat Calf Hole was being opened up, a dig was located higher up in the wood to the southwest. This was easily dug into a maze type cave Cueva del Ciervo (4117). Over a number of trips this was pushed and surveyed to nearly half a kilometre and linked to The Langdales (3034) via a 6m pitch - now the easiest entrance to the system. The cave contains a lot of bear prints and bones. It lies some 35m above Vaca and a number of pits in the floor were descended and sound testing carried out with a person in Vaca. However, no link between the caves has been made so far. One possibility is that this important find is part of a major maze system that once included Cueva de los Urros (2917) which is at the same altitude, but has been truncated by the wooded valley that lies between the two caves. If this is true then there may be a lot more to find of this maze complex.
   BigMat Calf Hole (3916) was found to have slumped at the connection crawl to Torca la Vaca (2889) as described above. This meant that two days were lost digging and shoring to gain access. The area around Should Have Gone To Survey School and Should Have Gone To Specsavers was looked at and a number of inlets and side passages surveyed. The leads in the far south around 5-Ways Chamber (should now be No-way Chamber?) and the end choke proved not to give up any new passage. However, a new pitch was located just short of the end choke and is still to be pushed. A shaft in Deep Rifts Passage was found to be 30m deep and closed down. Another rift went to 20m, but needs more gear. Also a passage at the top continues but needs bolts to traverse across the drop. There is still a good draught to encourage more work. Passages were found and surveyed north from the Frizzington Series around Pont Aven and near Ed's Birthday Passage where Doldie’s Draughting Passage heading north ended in good prospects with draughting pitches to descend and bolt traverses to cross. From the traditional entrance to Torca la Vaca (2889), the possible dig up a 3m climb at Red Pike Junction in the upper series was looked at and found to be a long term project to force a way on.

Phil Papard, May 2015

Survey updates
0048	Reñada (resurvey)	complete
0075	Picón	complete
2889	Vaca	complete
2964	Not Too Bad Pot	complete
3812	Yo-Yo	left until summer to remove estimated leg in batch 15-01
4046	Child Minders'	complete
4112	Cuesta de la Encina	complete
4117	Ciervo	complete

 
   The list below shows links to those 110 sites which were extended or newly discovered over Easter expedition 2015 (and the following month), or which have had surveys, references or descriptions updated, entrance photos or movie clips added, or entrances repositioned with a GPS.

Alisas 4119 cave; 4120 shaft; 4121 shaft; 4122 shaft; 4123 shaft; 4124 shaft; 4125 dig;
Arredondo 733 Vallina, Cueva; 1004 cave; 3278 Barcena Morel, Fuente de;
Barrio de Arriba 1561 Favorita, Mina;
Barrio de los Urros 3034 Langdales, The;
Bustablado 791 Molino, Cueva del (resurgence);
Camposdelante 3815 shaft;
Cobadal 4137 cave; 4143 shaft;
Cubija 75 Picón, Simas del; 76 Campo, Cuvia del; 4130 cave;
El Camino 137 Coreano, Cueva de;
El Naso 59 Molino, Cueva del; 65 Cofresnedo, Cueva de; 147 cave;
El Sedo 25 Risco, Sima-Cueva del;
Fuentecil 4136 dig;
Hornedo 2889 Vaca, Torca La; 2920 cave; 2947 cave; 2952 sink; 2954 resurgence & sink; 3300 shaft; 3916 BigMat Calf Hole; 4117 Ciervo, Cueva del; 4118 Pallet Hole; 4135 cave; 4149 cave; 4158 hole; 4159 hole; 4160 Isobel's Cave;
Ideopuerta 3812 Campizos, Cueva de los;
La Colina 1033 caves - 2;
La Collada 2308 shaft; 4147 dig; 4148 hole; 4150 shaft;
La Gatuna 4151 shaft; 4152 dig; 4153 dig; 4154 Hang-on Hole; 4155 hole; 4156 depression; 4157 depression;
La Helguera 4046 Child Minders' Hole;
La Secada 81 Carcavuezo, Cueva de; 148 cave; 261 shafts - 3; 565 Tres Niños, Cueva de los; 866 cave; 867 cave; 3409 cave; 3411 shaft; 3412 cave; 4016 dig; 4045 dig; 4115 cave; 4116 collapse; 4126 shaft; 4127 shaft; 4128 shaft; 4129 shaft; 4131 dig; 4132 dig (mp);
Las Calzadillas 1973 shaft; 2502 cave; 3759 shaft; 3760 shaft; 4133 shaft; 4134 caves - 4;
N Vega 812 shaft; 2133 shaft; 3153 cave; 4113 cave; 4161 shaft; 4162 shaft; 4163 shaft; 4164 shaft; 4165 shaft;
Navajeda 4111 Murciélagos, Cueva de los; 4112 Cuesta de la Encina, Cueva de la; 4144 cave; 4145 shaft; 4146 cave;
Ozana 16 Jivero 1, Cueva de; 2964 Not Too Bad Pot; 3884 cave; 3886 sink;
Riaño 107 Hoyuca, Cueva; 718 cave; 2691 Giant Panda entrance; 3234 Llanío, Cueva-Cubío del;
Riolastras 4138 dig; 4139 cave; 4140 cave; 4141 shaft; 4142 dig;
S Vega 40 Comellantes, Cueva del; 48 Reñada, Cueva-Cubío de la; 49 Somo, Torca del; 781 cave; 1175 Pino, Cueva del;

Summer

   Before the summer expedition started, the surveys and descriptions for a number of sites were updated. Simon Cornhill, with a trapped nerve in his shoulder, had the time to write up decent site and survey batch descriptions for the caves (2917, 2889, 2907, 3357, 2538, 2964 and 0124) he had been surveying. Pete Smith surveyed sites 0016 and 2382. These are all listed below.
   Andi Smith et al have documented more research information from Cueva de Asiul (site 61), this time as "Drip water electrical conductivity as an indicator of cave ventilation at the event scale". Further details can be found here.

Summer Expedition

The Northeast Sector including The Four Valleys System
    At Cueva de Carcavuezo (81) re-surveying (nearly 700m) continued in the entrance and connecting series with Llueva. Some 100m of new passage, Puffin the Beaver Inlet, at the start of the Western Series, was pushed to fairly near the surface and located using molephones and a new cave radio being developed by Ron Taylor. Also located was Green Cool Passage, the area below the main river sink in Matienzo. It was clear that the existing maps showed the river and sink in the wrong location and altitude. A number of surface surveys have corrected this so the map used by the Matienzo Cave Project is now (more) correct. Also linked in with this survey was the entrance to Carcavuezo and the hole that has opened up in the track to the cave (Track Hole, site 4190) which was looked at but needs considerable digging to progress.
   In the area of La Secada above the Carcavuezo sink and the nearby "Mushroom Field", Tres Niños (565) was checked out for further work in 2016. It lies above the choke at the end of Southern Passage off the Afternoon Stroll in Carcavueso that was resurveyed this summer. Six new sites were located with work done at two of them. Site 4179 was pushed for 10m where more work is needed, and site 4214 was located on the way up to dig 4131 (found at Easter). After some time digging at 4131 - which had a small outward draught but would need a lot of work to continue - digging turned to site 4214. This is an easy dig with a very good outward and is well worth a return in 2016 as it lies in a good location for possible access to higher levels in the Four Valleys System that may exist below.
   In Secadura, the choke at the western end of Lenny’s Cave (3721) was snappered and pushed but no breakthrough was made.
   In the Riaño area, seven new sites were found and located. Of these site 4173 ended at a low dig after 14m; site 4175 went for some 10m after the 3.5 m entrance drop to a narrow continuation; site 4187 was pushed to a choke, but towards the bottom of the 4m entrance a passage with a draught needs more work to enter and 4188 (Shrewd Find) went for some 12m to a calcited boulder dig. In Cueva de Riaño a section of survey was checked and a 3D video taken.

Solórzano and the Riolastras Area
   In the Riolastras area, eight new sites were located of which 4184 was pushed down 12m to a dig, 4185 needs digging to make more progress and 4220 is an undescended shaft. Site 4141 was pushed to 17m deep to a choke and sites 4140 and 4089 were checked out but did not have good potential, although the later does draught. Daddy Day Care Centre ( previously Child Minders Cave, 4046) was pushed through a short duck to a continuation and a clear sump. A diver is now needed.

Northwest Sector
   Doldy's Draughting Rift passage in Torca la Vaca (2889) was pushed and 100m of new passage surveyed up to a large undescended pitch. A new entrance Cueva Cuba Libre (4182) was found from the inside at the end of Deep Rifts Passage. Two thin members of the team squeezed out and one found his way to the team working on BigMat Calf Hole to help remove a boulder to make the entrance easy for everybody. This new entrance is in a eucalyptus wood with thick undergrowth making the entrance hard to get to. It provides an easy route to the end of the Deep Rifts area but, due to the crawl at the start, BigMat Calf Hole remains the best entrance to the rest of the system beyond Lake Bassenthwaite.
    A pushing trip in Cueva del Ciervo (4117) via The Langdales (3034) dropped a pitch and linked this cave to Torca la Vaca giving the system six entrances.
    There was also one trip into the upper levels of Torca del Vaca by the original entrance when some video was shot. Torca la Vaca is now only a little short of 20km length and should reach that figure soon.
   At BigMat Calf Hole the connecting crawl was enlarged to take 2m of the same sort of tube as had been installed in the entrance. This excavation needed a lot of work and capping as it was found that the crawl is a boulder and mud-filled rift with very hard sandstone walls that a 1.5kW breaker would not touch. To allow us to get the tubes down the entrance it was cut in half then each 1m part split into four along their length so they would fit down the entrance tube. This "tube kit" was then equipped with connecting pegs and metal joining straps so it could be assembled underground. Work was halted when the Cuba Libre entrance was found as it was first thought it was an easier way in. After it was realised that BigMat Calf Hole was still needed, the "tube kit" was installed in a couple of hours and foamed in place. This should stop any "mush" from filling the crawl as had happened over the last winter. Work is still needed to secure the scaffolded area at the bottom of the entrance.
   In the San Antonio area between Torca la Vaca and Fuente Aguanaz five new sites (4202-6) were found, pushed or dug and GPSed. Most of the sites draughted and 4203 and 4205 were pushed to a section where a thin person is needed to continue and site 4202 ended at a 20cm hole with the draught coming out. Resurgence 1254 was checked but no progress made. In Cueva Laberinto (3268) some digging took place in the NW area but more work is required.
    In the RioTuerto area, site 3901 at Moncobe was dug using caps, but more work is needed to make progress, and at Ideopuerta the three holes that form 3752 were found to be draughting out strongly and are worth more work.
    An old tourist cave and archaeology site, Cueva de la Fuente del Francés (4171), adjacent to the river Aquanaz near the now closed water bottling plant and almost completely excavated of its extensive archaeological deposits decades ago, was photographed and the 126m of passages and stairs surveyed. It was clear this was once a popular visitor site and, while surveying, there was a number of visitors.
    The missing bit of stream way on the survey of Riocueva (4042) via the Torca de los Cañaos (4043) entrance was surveyed together with some missing oxbows of the downstream area. The upstream extension found in 2014 was pushed to find some 280m of new passages on different levels. The stream continuation is low and in cow muck, so it must be close to a where it drains from a farm - not a good prospect to push. With this work the cave is now over 5.1km long so we have added about 2km to the previous surveyed length. Some side passages and digs remain that may be worth a look, but the main surveying work is probably now complete.
Expedition article by Phil Papard

New surveys & updates from summer expedition
0023	Orillón (resurvey) PS	complete (Revised autumn)
0048	Reñada (resurvey) AN	complete
0081	Carcavueso (resurvey) PF	part of the 4VS
0083	Chica (resurvey) ND	complete
0841	Fresnedo 2 JC	complete
2889	Torca la Vaca System JC	complete
3234	Cueva Llanío JC	complete
3721	Lenny's Cave JC	complete
4043	Cañaos JC	complete
4046	Daddy Day Care JC	complete
4117	Ciervo JC	complete
4171	Francés JC	complete
4189	Ruffles JC	complete
4215	shaft ND	complete
4216	cave ND	complete

   The list below shows links to those 140 sites which were extended or newly discovered over the summer expedition 2015 (and the previous month), or which have had surveys, references or descriptions updated, entrance photos or videos added, or entrances repositioned (with GPS, surface survey or off Google Earth).

Alisas 1073 shaft; 1076 shaft; 1676 shaft; 4172 dig;
Arredondo 733 Vallina, Cueva;
Barrio de Arriba 1561 Favorita, Mina;
Barrio de los Urros 2917 Urros, Cueva de los; 3034 Langdales, The;
Bosmartín 3932 shaft;
Cobadal 4206 dig;
Cubija 71 Mostajo, Torca del;
El Naso 61 Asiul, Cueva de; 1438 dig; 1543 cave; 3435 shaft; 3559 cave; 3586 dig; 4181 shaft; 4189 Ruffles, Cueva de; 4191 dig; 4192 shaft; 4193 hole; 4194 shaft; 4195 hole; 4196 hole; 4200 shaft; 4207 cave; 4208 cave; 4209 cave;
El Sedo 25 Risco, Sima-Cueva del;
Fresnedo 841 Fresnedo 2, Cueva;
Hornedo 767 Wild Mare, Cave of the; 2889 Vaca, Torca La; 2907 Stink Pot; 3470 shaft; 3916 BigMat Calf Hole; 4117 Ciervo, Cueva del; 4182 Cuba Libre, Cueva de;
Hoznayo 4171 Fuente del Francés, Cueva de la;
Ideopuerta 3752 digs-3;
La Colina 83 Chica, Cueva; 94 Bardalones, Cueva de las; 272 Cubillones, Abrigo de los; 1008 cave; 1557 cave; 1558 cave; 4211 cave;
La Gatuna 3357 Nabo, Cueva del;
La Helguera 4046 Arroyo de Canastrillas, Cueva del;
La Secada 81 Carcavuezo, Cueva de; 415 cave; 565 Tres Niños, Cueva de los; 880 dig; 1017 dig; 3895 cave; 4016 dig; 4045 dig; 4131 dig; 4178 shaft; 4179 cave; 4180 cave; 4190 Track Hole; 4212 dig; 4213 dig; 4214 dig;
Llueva 114 Llueva, Cueva;
Moncobe 2538 Cubillón, El; 3901 dig;
Muela 4215 shaft; 4216 cave;
Navajeda 2382 cave;
Ozana 16 Jivero 1, Cueva de; 23 Orillón, Cueva del; 1161 Malbujero; 1162 Orillonzuco; 2964 Not Too Bad Pot; 4201 shaft;
Riaño 105 Riaño, Cueva de; 107 Hoyuca, Cueva; 3234 Llanío, Cueva-Cubío del; 4173 cave; 4174 shaft; 4175 shaft; 4176 cave; 4177 dig; 4187 shaft; 4188 Shrewd Find;
Riolastras 4089 cave; 4140 cave; 4141 shaft; 4183 cave; 4184 shaft; 4185 cave; 4186 cave; 4217 cave; 4218 cave; 4219 cave; 4220 shaft;
S Vega 36 Vera Negra, Torca de la; 40 Comellantes, Cueva del; 42 Cefrales, Cueva de los; 48 Reñada, Cueva-Cubío de la; 177 Cuevuca, La; 264 Coterón, Torca del; 310 cave; 311 dig; 333 Azpilicueta, Torca de; 335 cave; 458 Hidden Hole; 495 dig; 529 Pino, Torca del; 675 shaft; 1187 dig; 1189 Dairy Dig; 1338 shaft; 1471 Papá Noel, Torca de; 1489 shaft; 1490 shaft; 1492 shaft; 1901 dig; 3477 hole; 4166 shaft; 4167 shaft; 4168 shaft; 4169 shaft; 4170 cave; 4197 shaft; 4198 hole; 4199 shaft; 4210 Cefrales, Cueva de (bottom entrance); 4221 Reñada, Cueva-Cubío de la (top entrance);
San Antonio 1254 cave; 3268 Laberinto, Cueva; 4202 shaft; 4203 cave; 4204 cave; 4205 cave;
Secadura 124 Crecidas, Surgencia de las; 3721 Lenny's Cave;
Villaverde de Pontones 4043 Cañaos, Torca de los;

Autumn

September and October Expeditions

   Two small, separate, teams were out in Matienzo in early autumn. The first team of four were based at La Cavada working in the west and north of our area; the second team of seven was based in Matienzo and mainly worked in the South Vega and Vallina areas. In total about 1km of new cave was surveyed, 25 new sites/caves found and about 250m of resurvey work in the South Vega system completed.

Southern sector
   In Cueva Vallina (733) Rupert Skorupka prepared for a major push at Easter 2016 in the main downstream sump series. This work took 9 trips, a number of which were solo. The line in the first few sumps was found to be broken and tangled, this was removed and the sumps relined. Gear was taken to a safe spot near the first sump for the push next year. These sumps are a very important lead as we now know this water goes to Reñada and could be the key link between these systems. (See Easter 2015 report).
   The team pushed and surveyed the passage found during the summer that leads off from the “sump” bypass in the Rio Rioja. Over two trips 716m of new cave were pushed and surveyed. The majority was in a passage formed on a series of parallel joints that seem to be associated with a fault. The passage is a phreatic rift about a metre wide but with many sharp flakes which in some cases completely divide the passage, all making travel slow. There is no sign of vadose development and it appears the passage was formed by slow moving phreatic water and then drained fairly quickly (in geomorphologic terms). There is little sediment in this series. This extension runs parallel to the first five sumps and ends near the dry section prior to Sump 6. The passage was explored to where the passage divides and reaches two pitches (4 and 8 metres deep) with passage seen continuing both across and down the pitches. Also a side passage half way along led to a more complex draughting area with open leads. The pitches at the far end need bolting gear and tackle (partly to avoid loose walls and roof) and this series will be pushed at Easter 2016. There is a good draught which suggests it must go beyond the dry passage between two sumps! Due to the restricted nature of the passage, and the sharp flakes, it will not be a useful access route for diving sump 6 – it’s much easier to use the under water route.
   In Cueva del  Comellantes (0040), a climb at the SW end was pushed and dug into 84m of well decorated inlet passage. Other climbs were checked and more re-surveying work carried out. In Cueva-Cubío de la Reñada (0048) the water level was found to be too high at the Blow Hole to risk going further, and re-surveying work was carried out in the direction of Comellantes in the entrance series.  
   The area below the top of Alisas was checked out during a walk with limited gear. Six new sites (shafts and digs) were found (4237 to 4242, listed below). Some digging was carried out but all need looking at in 2016.  The Torca del Hoyón (0567) depression was visited and a partly filled hole (site 4245) found in the base. The shaft entrance was located on a later visit. This is one of the key sites for water tracing in the next few years. Above the entrance, a hole (site 4246) in the same closed depression was found where a stream could be heard (quite wet weather) and this also needs checking out with gear.  At Calzadillas, three small new caves were found (4232 to 4234, listed below) but all were choked and have low prospects.

Northeast sector 
   Cave 718 in Riaño, was checked to see if it could be pushed to Tilers’ Way in Cueva Hoyuca (107). It was explored to a possible corner and pendant which looks similar to a corner seen in Tilers’ Way. The site needs more work and a wetsuit on the next trip.
   In the same area, Church Entrance (2903) and sink 2857 were checked out. The farm slurry in Church Entrance seemed to have dried up: still muddy but not smelling now. The water sinking at 2857 is the same size as in 718 and is 99% certain to be same stream. The choke just inside the entrance of 2857 would need a lot of work to progress and, given the prospects, is not worth the effort.

Northwest sector 
   In the Ideopuerta area, sites 2749 and 2750 were dug but, although the former draughts well from a narrow slot, both sites were not thought to be worth more work. A new 8m choked shaft (4235) was found nearby. In the Moncobe area, in El Cubillón (2538), a trip to the end had to be curtailed due to boulders having moved, with a risk of blocking the way out at the breakdown chamber at the bottom of the second pitch. Site 2536 was looked at but bolts are now needed for the 4m pitch to reach the final choke, as there are no safe belays.
   In the Navajeda area, 7 new sites were found and pushed (4222 to 4228, listed below). Three sites needed some work to complete but, in the end, all were found to choke or have a narrow slot as the way on. The exception was site 4227, a large gully/rift, which was choked but may be worth a further look given its size.
   At Hornedo, two choked shafts (4230, 4231) were found and explored and a well decorated cave (4229) was pushed and surveyed to 91m, and would benefit from a further look. Site 3176 was revisited to see if progress could be made, but no way on was found.
   At Camposdelante, a side passage in Civil War Cave (3543) was dug and some progress made, but this will be a long term dig. Site 3814 was dug but needs a lot more work and, given the lack of draught, is a low priority.
   At site 4050 in the Garzón area, the final choke was inspected but it would need extensive digging. The cave was surveyed to over 110m.
   Using The Langdales (3034) entrance, the Aardwolf Country pitches into Torca la Vaca (2889) from Cueva del Ciervo (4117) were surveyed and de-rigged.
   In the Hoznayo area, the river arch, Gruta del Diablo (4244) was surveyed to complete the work on this and the adjacent old show cave, Cueva de la Fuente del Francés (4171). The top entrance in the latter was found locked shut with a hammered over bolt. The area to the east of here was looked at (prior to going for the ferry home) and a dig (4243) above Pozo de la Hoya (4017) was found. This site is well worth  excavating (caps may be needed) as it may link with the old remnant cave 4017, which was explored by the Spanish many years ago and still needs a new survey by the Matienzo Caves Project. The area between here and Fuente del Francés is well worth a look, but it would be best at Easter when undergrowth is lower - but prospectors will still need good protective clothing.

September & October Expeditions report by Phil Papard

New surveys & updates from Sept / Oct expeditions
4229	resurgence PG	complete plan & elevation
4050	cave PG	in hand
0040	Comellantes AN	complete to Nov. 2015
0048	Reñada AN
4244	Francés/Diablo JC/AN	complete
0733	Vallina AN	Easter 2015 : October ext.
4117	Ciervo JC	complete
2889	Vaca JC	complete
0023	Orillón PS	complete
3543	Civil War PG	complete

   The list below shows links to those 23 sites which were extended or newly discovered over the September 2015 trip, or which have had surveys, references or descriptions updated, entrance photos or videos added, or entrances repositioned (with GPS, surface survey or off Google Earth).

Camposdelante 3543 cave; 3814 hole;
Garzón, Solórzano 4050 cave;
Hornedo 3176 dig; 4229 cave; 4230 shaft; 4231 shaft;
Ideopuerta 2749 dig; 2750 dig; 4235 shaft;
Las Calzadillas 4232 shaft; 4233 shaft; 4234 cave;
Moncobe 2536 cave; 2538 Cubillón, El; 4236 shaft;
Navajeda 4222 shaft; 4223 shaft; 4224 shaft; 4225 shaft; 4226 shaft; 4227 shaft; 4228 shaft;

   The list below shows links to those 31 sites which were extended or newly discovered over the October 2015 trip, or which have had surveys, references or descriptions updated, entrance photos or videos added, or entrances repositioned (with GPS, surface survey or off Google Earth).

Alisas 567 Hoyón, Torca del; 721 shaft; 722 shaft; 1817 shaft; 4237 dig; 4238 shaft; 4239 shaft; 4240 shaft; 4241 depression; 4242 shaft; 4245 dig; 4246 digs;
Arredondo 733 Vallina, Cueva; 752 Rotura, Hoyo de;
Barrio de los Urros 3034 Langdales, The;
El Naso 61 Asiul, Cueva de; 65 Cofresnedo, Cueva de;
Hornedo 2889 Vaca, Torca La; 4117 Ciervo, Cueva del;
Hoznayo 4171 Fuente del Francés, Cueva de la; 4243 dig; 4244 Diablo, Gruta del;
Riaño 107 Hoyuca, Cueva; 255 resurgence; 718 cave; 2857 sink; 2902 cave; 2903 Church Entrance (Hoyuca entrance);
S Vega 40 Comellantes, Cueva del; 48 Reñada, Cueva-Cubío de la; 333 Azpilicueta, Torca de;

November Expeditions

    The November weather in Matienzo was exceptionally pleasant. Santander, the nearby Cantabria capital, had its warmest November for 55 years. Nine cavers visited over a week to a fortnight.

Southern sector
   The "final" version of the Orillón system re-survey has been produced by Peter Smith. A 5-hour digging trip in November in this Ozana cave enlarged the draughting dig area at the end of the streamway, making future excavations easier. Peter put optical brightener into the stream in late November (after the warm and dry spell had broken) and this was detected at the resurgence to the Sistema Mortiro-Esquileña (site 0005-4271) on the outskirts of Riba. It is most likely that the water from Orillón first resurges into the large (500 x 500m) Mortiro depression (at site 4272) before sinking into the Mortiro cave. (A further trace was carried out in January 2016.)
   Three holes (sites 4247, 4248 and 4249) have been identified which may be associated with Torca del Hoyón. These are out of our current permit area but are catalogued for "completeness", courtesy of Guy Simonnot.

Northeast sector
   A trip in Cueva Llueva, checking out possible leads in the high level series discovered at Easter 2014, failed to find any ways on. A trip into a series surveyed in 2008 above Torno Chamber in Cueva del Torno investigated various leads leaving one - a possible passage at the top of a bolt climb - for the future. An interactive survey with photos has been produced for site 143.

Northwest sector
   In Riaño, site 4260 and 4263 are holes that require further investigation.
   In the Torca la Vaca System, an inlet (Bernard) on the south side of Suit Wrecker Inlet was surveyed for 214m and the end of Suit Wrecker was pushed for nearly 600m, through Friday the 13th Passage, ending in a choke. Cueva de Collada is about 425m away at this point. The surveyed length of the Sistema de Torca la Vaca is now 20376m.
   Close to the entrance of El Cubillón, a traverse to the left of the entrance (chasing a cold draught) discovered a shaft about 25m above. This was dropped and emerged in the cliff close to Cubillón entrance.
   At Ideopuerta, a recent collapse (site 4258) requires further investigation.
  At Camposdelante, the sink area at site 3180 was examined but all leads appeared choked. A short rift (site 4250) was explored above the sink.
   More investigations in the area of Mina Favorita at Barrio de Arriba uncovered another mine with natural chambers. The 18m deep, natural shaft just inside the entrance drops to chambers and terminates after a chest-deep lake. La Cueva en una Mina (site 4251) has been surveyed for 229m. Nearby, a hole in a small cliff was explored for 12m (site 4252). Also at Barrio de Arriba, various small sites and digs were documented (4259, 4264, 4265, 4266, 4267, 4268, 4269, and 4270).These out-of-permit-area explorations around here have been approved by, and reported back to the Grupo de Espeleología Pistruellos.
   Near Navajeda, a number of sites were documented. Site 4253 is unexplored and about 9m deep; site 4254 is a climb down between boulders to a small chamber; site 4255 would require dropping down past a mattress in a rubbish and syringe littered hole - about 8m deep. Possible digs were also found at sites 4256 and 4257.
   In San Antonio, a small resurgence cave (4261) waits exploration and site 4262 is described as an "uninspiring dig"

New surveys & updates from November expeditions
2889	Vaca JC	complete
0023	Orillón PS	complete
4251	Cave in a mine PG	complete (temporary)

   The list below shows links to the 59 sites which were extended or newly discovered over November 2015, or which have had surveys, references or descriptions updated, entrance photos or videos added, or entrances repositioned (with GPS, surface survey or off Google Earth).

Alisas 567 Hoyón, Torca del; 4242 shaft; 4247 Tilina, Torca; 4248 Casa Blanca, Torca de; 4249 Gallinero, Torca del;
Arredondo 733 Vallina, Cueva;
Barrio de Arriba 4251 Cueva en una Mina, La; 4252 cave; 4259 rift; 4264 shaft; 4265 shaft; 4266 cave; 4267 cave; 4268 dig; 4269 mine; 4270 shaft;
Camposdelante 3180 sink; 4250 cave;
Fresnedo 2366 Torno, Cueva del;
Garzón, Solórzano 4050 Pipe Cave;
Hornedo 2889 Vaca, Torca La; 4117 Ciervo, Cueva del; 4229 cave;
Hoznayo 4171 Fuente del Francés, Cueva de la;
Ideopuerta 2751 dig; 3420 Hoyo Carabo, Torca de; 4258 collapse;
La Gatuna 394 Collada, Cueva de;
La Secada 143 shaft;
Llueva 114 Llueva, Cueva;
Moncobe 2538 Cubillón, El; 4274 shaft;
Navajeda 1072 Bocarón, Cueva del; 2383 Bocarones 2, Cueva de los; 4253 shaft; 4254 cave; 4255 shaft; 4256 dig; 4257 dig;
Ogarrio 284 caves; 4275 resurgence;
Ozana 23 Orillón, Cueva del; 1162 Orillonzuco;
Riaño 2650 Dead Goat Hole; 4173 cave; 4188 Shrewd Find; 4260 dig; 4263 dig;
Riva 2 Coverón, Cueva del; 5 Mortiro, Cueva del (top entrance); 4271 Esquileña, Cueva de; 4272 resurgence (E); 4273 resurgence (SW);
San Antonio 3106 cave; 3214 cave; 3268 Laberinto, Cueva; 4261 resurgence; 4262 dig;
Seldesuto 1205 dig;

Autumn articles by Juan Corrin (completed 19/4/2016)