Tresviso 2019

Andara (Eastern Massif) viewed from Tresadura (looking South) (Phil Walker)

The 2019 expedition is only 5 weeks away. Hopefully some interesting blog posts will be created, but firstly, as per previous years, a bit of a brief overview of expedition:

Overview & brief history:
The Picos de Europa is a range of mountains 20km inland from the northern coast of Spain, forming a westerly extension of the Cantabrian Mountains. It consists of three main areas, the Western, Central and Eastern Massifs.

  • The Western Massif is to the west of the Rio Cares and has been explored by a selection of clubs including Oxford University Caving Club (OUCC), Seccion de Espeleologia Ingenieros Industriales (SEII), York University Cave and Pothole Club (YUCPC), Sociedad de Espeleologia Geologicas (SEG) and Speleo Club de Paris (SCP). This now includes the area under exploration as part of the Ario Caves Project.
  • The Central Massif is between the Cares Gorge and the Rio Duje and has been mainly explored by the Speleo Club de Seine (SCS).
  • The Eastern Massif is to the East of the Rio Duje. Lancaster University Speleological Society (LUSS) were exploring the Eastern Massif from the early seventies to 1987 with the help of SEII.

It was the Eastern Massif (or Andara) that drew the attention of LUSS in the early 1970s. In the early years exploration was mounted from the mountain village of Tresviso and exploration was dominated by the resurgence cave Cueva del Nacimiento (Cueva del Agua) located at the foot of the mountain range. The resurgence flows into a canal that contours the Urdon gorge with an average flow of 2 m3/s and the cave behind the resurgence leads to >12 km of surveyed passage and a height gain of over +534m.

The catchment is some 40 km3 and includes caves such as Torca Jou Sin Tierre (CS-9) at -1203m deep and Torca del Cueto de Los Senderos (Sima 56) at -1169m deep.

Morning Chamber, Cueva de La Marniosa (Joe Daniels)


In the late 70’s LUSS pushed Cueva del Nacimiento to around the 11km and +300m mark, but after several years the cave was abandoned as all the major routes sumped and no continuation could be found. LUSS then turned their attention to the Andara region higher up the mountain range and sought caves that would drop into the Nacimiento system and hopefully create a record-breaking >1500m traverse. They found a number of deep caves around this ‘top camp’ area; Sara, Tere, Flowerpot, Dosser’s Delight and Sima 56 were all pushed to respectable depths but a
connection remained elusive.


The discovery of newer and deeper systems, plus improved GPS, have changed the figures slightly but a connection between the deep potholes and resurgence would create; a cave in the top 10 worlds’ deepest, deepest in Spain and potentially one of the the deepest underground traverses in the world.

Top EntranceAreaAlt(m)Current Depth (m)Vertical Range (m)
S-33 Torca de la Hendida Samelar2100-4521620
CS-9 Torca Jou Sin Tierre Cueto Senderos 2074 -12031594
Sima 56 Cueto de Los Senderos Cueto Senderos 1975 -11691495
T82 Karen – 2.6 Sara Grajal (Sara depression) 1880 -5911400
T145 – Pozo Castillo Mazarassa 1870 -3091390
2.24 Tere Grajal (Sara depression) 1820-7921340
FT39 Compromisso Mazarassa 1820-3131340
T169 Flowerpot Pico Boro 1785-7231305
T173 Dossers Delight Pico Boro 1706-8311226
T190 Septrin Pico Boro 1696-1801216
3.2 Torca Branarredonda (Fallen Bear) Samelar 1589-4561109
T510 Cueva Entre Cuetos Sierra del a Corta 1305-117825
T69 – Pozo Motilla Sierra del a Corta 1248-70768

Table: Potential depth if connected to Cueva del Nacimiento (2017).

Note: There are at > 70 sites at higher altitude than CS-9 that would surpass -1600m deep through trip, with some close to -1800m depth.

Survex – Mountain range looking E-W

Expedition Dates
• 31 st August 2019 to 14th September 2019 – main expedition dates

Objectives
The expedition has several goals. The following are a few primary objectives:

Cueva del Nacimiento

  • Jurassic World – The Sandy dig, draughting lead, now only an hour from camp
  • Pina Colada Bypass – calcite aven to climb
  • Joe’s Crack – continuing shaft behind Death Race camp.
  • Teeth of Satan – Wet Aven – +30m aven with draft and calcite squeeze, requires enlarging.
  • Dan’s Big Room – unexplored section of maze in area of Dan’s Big Room, Peanut Chamber and Winter Gardens
  • Parting Friends – a dive of the Parting Friends sump is planned.
Pena Coloada Sump (CUeva del Nacmiento) (Rob MIddleton)

Cueva de la Marniosa

  • Beyond Sump 2 – undescended 6m pitch
  • T20A Silvestre – Marniosa – first through trip to be completed
  • T20A Silvestre – upstream leads, heading toward the Valdelafuente

Secondary Objectives:
Time and resources permitting there are several secondary objectives that will be attempted:

Downstream Marniosa (Joe Daniels)


Sistema Castillo
A large mine and natural cave complex in the Minas de Mazarrasa area. Pozo del Castillo series was explored to – 292m depth in 1983, with either a howling draft or roaring waterfall beyond a constriction at the limit. The potential of the cave is significant but currently a collapse prevents getting to the end. Pozo Natacha series ends at -309m depth and is close to the same point in Castillo.

  • Pozo Del Castillo – shoring and bypass of rock collapse Castillo remains a major lead, if we can get past the blockage! In 2018 the snow level had dropped and possible to get into the next section.
  • Pozo del Castillo – other entrances. FT16 entrance snow plug would appear to be the same blockage in lower Castillo passage. Snow plugs are reported further into the cave, so another entrance must exist!
  • Pozo del Castillo – surveying of Natacha upper series and locating possible surface entrance,


Valdelafuente / Sobra Valley

  • Re-locate draughting surface entrance on Valdelafuente, close to 80m aven beyond Sump 1 in Cueva del Marniosa,
  • Yorkshire Inlet in Cueva del Marniosa. Exploration of col above aven

Sierra del a Corta

Above the furthest reaches in Nacimiento is the Sierra del Corta. A heavily wooded area with a number of promising leads, that could potentially drop into Nacimiento and provide an easier route into the back-end to aid exploration at the far reaches.

  • T554 – large 100m shaft on the Sierra del a Corta, this requires some digging at the bottom,
  • Al2 – a drafting shaft not yet bottomed. Jurassic World in Nacimiento appears to be heading directly towards this site,
  • T294 Oh What Pot (La Gobia) – continuing passage,
  • Surface prospecting close to vicinity of Terror Firma in Nacimiento. Terror Firma is only 40m vertically and 200m horizontally from some parts of the surface in the Sierra del a Corta region.

Other

  • Locate and descend FT43, this draughts strongly. It is almost directly above Boulder Chamber in T87 Mazarrasa and would provide bypass to collapse at T87 entrance.
  • Prospecting on Hoyo Oscuro and Hoyo Evangalista. Highest entrances on the mountain range.
  • Mine 2.32a – there is large unexplored level (with tram lines) leading to unexplored passage.
M6 Toll Bypass, Cueva del Nacimiento (Arwel Roberts)

Torca del Oso Caido (Fallen Bear)

On the northern slope of Samelar is an area called Brañaredonda, where Torca del Oso Caido or Fallen Bear is located.  In the 70’s LUSS explored down the main pitch and discovered a few smaller pitches before leaving the cave to explore elsewhere.  AD KAMI revisited the cave in the 90’s and allegedly moved a small rock at the foot of one pitch and discovered nearly -400m depth of new cave.  Accurate descriptions of what is at the end of the cave, vary from ‘nothing’ to a half-submerged passage onto an undescended 40m pitch.

The nature of the cave passage (huge ramps) is similar to Nacimiento and the location places it coming down the mountina between Nacimiento and Rio Chico, so a cave of much interest.  Finally, on this expedition I was able to convince a number of people to visit and report back.

Fallen Bear Entrance
Fallen Bear Entrance

 Friday 14th July (Chris Jones, Hannah Moulton, Emma Battensby)

 Excited by the prospect of some sunshine above the cloud at the top of the hill, the air conditioned drive to the White House was enjoyed. Armed with two different sets of GPS coordinates (following a very quick lesson)  Emma, Chris and Hannah set off on a bear hunt. Initially following the LUSS coordinates we located an entrance below the Bejes track. Having decided that the entrance did not match the (minimal) description of Fallen Bear we figured out how to input the AD KAMI coordinates and continued to search. These took us above the road but to no avail. It was clearly lunchtime. Tasty sandwiches and tea (from some lovely thermos flasks) were enjoyed before deciding to drop the entrance on the LUSS coordinates just to be sure. Whilst Chris and Hannah kitted up, Emma wandered down the track to try and make more sense of the description from Bejes. After watching Chris and Hannah disappear down the shaft Emma walked back up past the White House to join the team at Castillo/Segura II, narrowly avoiding being mauled by a large, scary canine!

Hannah rigged, following spits. Chris followed surveying. ~70m deep. A small climb at the bottom (not previously passed) lead to a small sump (5-10m of passage). De-rigged.

Saturday 15th July (Hannah Moulton, Chris Jones, Bob Clay)

 Previous coordinates followed to exact location as yesterday despite grid change.  Kit retrieved from Friday cave and mark followed back to GPS point successfully.

 Underground

The entrance shaft was cool. Hannah rigged with an entourage of birds flying around. Chris and Bob followed doing an awful survey (an 18m leg is missing between stations 3 & 4…). Hannah was located happily rigging on the way we’d decided to go while Chris and Bob looked at some dead dogs. When it became clear it lead to the LUSS deep point it was de-rigged and the main chamber explored to find the way on, which continues under a breakdown chamber into smaller ancient phreatic passage, where the bear lives.

Hannah on Fallen Bear Entrance Pitch
Hannah on Fallen Bear Entrance Pitch

Sunday 16th July (Hannah Moulton, Chris Jones, Bob Clay)

The 1996 KAMI route was located by passing the bear and dropping the 13m shaft. A small muddy ramp leads to the ‘50m pitch’. On the way a small down climb lead to a short continuation, but it did not go. The 50m pitch was a long ramp, split by a breakdown chamber and a stal ledge, was very Aguaesque. Part way down a parallel shaft was spotted through some stal, Bob bolted his way down this while Chris and Hannah began to explore El Chaos. One lead (window) in the ceiling was spotted early on which would require a short bolt climb, not that promising to be fair. The Chaos is fairly chaotic. We returned to the base of the 50m pitch to cook Bob some lunch and returned to the surface, his shaft went down ~12m, where he could get off the rope and walk to a large clean aven, a further short pitch lead into a meander back under the original pitch, no way on. The remaining kit was stashed at the base of the entrance shaft (which probably needs de-rigging). There is a lot of air movement in this lower part of the cave and it is cold!

  • A good sling is required to replace Chris’ belt rebelay at the top of the 13m pitch.
  • A deviation just above the 1st ledge on the main pitch would be nice to reduce a short section of rope rub (which can be avoided with long legs or a walk along the boulder ledge).
  • Kit left:
  • 1x petzl portage + Dick
  • 50m and 20m static
  • Hitachi Drill (TL)
  • 1 full drill battery
  • 2 drill bits (TL and PW)
  • 1 Hammer (CJ)
  • 1 Skyhook (CJ)
  • Electrical tape
  • 4/5m 6mm cord
  • 16 hangers (NO BOLTS)
  • 4 hangers (with spits)
  • 21 maillions
  • Survey and description of cave
  • No deviation krabs.

 

Wednesday 19th July (Dave Powlesland, Tom Lia)

 The night before had started with extensive planning and much deliberation as to what we were going to look at in Fallen Bear Cave… Although the bar had distracted us a fair amount, leaving us weary for our early start when we awoke the following morning.

Fallen Bear Entrance Pitch
Fallen Bear Entrance Pitch

So we had an early 11am start (expedition early) we marched up the hill via the many shortcuts to be at the cave for around midday. Neither of us had been down the cave before, but heard route finding was a blast. After a quick descent of the gaping gill sized chamber we immediately got lost. EAST WEST EAST WEST – — – – -yes the old description was incorrect!!!!  After finally finding the correct direction out of the way down to the end of the cave we swiftly descended through a maze of smaller, tight pitches to El Caos (after picking up drill, rope and bolting kit from the main entrance chamber).

As per previous reports…. This really was the CHAOS!!! (El Caos) Fallen, stricken, loose, dodgy, formidable boulders everywhere we could go.  We continued down a 45 degree slope, over boulders, loose rocks and mud.  Several free climbs and a few scree slope traverses lead us eventually toward the end of the broken down passage. But this wasn’t the end of it. The height of the passage reduce to body width, where we had to thrutch our way down and through the narrow, low passage.

Several attempts at finding possible side passages and unexplored areas had lead us in circles with only a few small avens confirmed as possible leads. As we progressed to the lower reaches of the cave we encountered the lower pitches that Dave swiftly drilled and rigged for us to continue. We dropped the ‘27m’ pitch that soaked up a 50m rope (left rigged). This whole section a cave is a bit of a variation and the pitch we rigged seemed the most straightforward to descend.  After a crawl through boulders and a short squeeze, we popped our head over the final pitch, which was described as a 37m pitch, however it looked as though a 50-60m rope was needed. The final pitch into the chamber was very impressive and presented a different character to the rest of the cave, this was an atmospheric wet, draughty cold chamber. One of our aims was to see one of the marked avens at the top of this chamber. There is clearly a large window with a mender/shaft heading away from us, and away from the rest of the cave. It should be aim of the next expedition to push this meandering window to see if it links into another system.

AAARRRRGGHH FLAP FLAP – ARRRRRRGGGGHHHHHHHHHHYYYYYY (Dave says) but the flap was not from a human ….. It was from some sort of beast!!!  FLAP FLAP the beast (small bird), was a crow, who had chosen to make its nest in the entrance shaft. The crow perched itself on Dave’s shoulder in a displeased manner. Tom had no such problems. The crows were merely dispersed by a swift backhander.

Entrance pitch derigged – need deviation for very top – need deviation for ledge half way down main pitch. 79m pitch marked – say 60 and 40 would work well on re-rigging.

50m rope required for lowest pitch

Lightweight aid climbing gear for numerous marked leads on survey at lower areas of cave.

The fallen bear
The fallen bear