Tresviso 2018

Prospecting for caves (Sam Deeley)

Expedition Dates

  • 1st September to 15th September 2018 – main expedition dates

Objectives

The expedition has a number of goals.  The following are a few primary objectives:

Cueva del Nacimiento

  • Jurassic World – Terror Firma – multiple avens and climbs,
  • Pina Colada Bypass – a 3-10m rift leads off from the Pina Colada sump.
  • Joe’s Crack – un-descended 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 and Winter Gardens
  • Parting Friends – a dive of the Parting Friends sump is planned.
DR traverse (Chris Jones)

Cueva de la Marniosa

  • Beyond Sump 2 – a dive of sump 2 and exploration beyond is planned

Pico Boro (SUSS)

SUSS are also involved and will take on responsibility for exploring either  Flowerpot on the Pico Boro area.

  • FlowerPot – re-rigging and exploration of leads
  • Surface sweep and logging of entrances in Sara Depression (around camp)
  • Surface sweep and logging of entrances in Pico Boro area


Secondary Objectives:

Time and resources permitting there are a number of secondary objectives that will be attempted:

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!
  • 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,
  • Pozo del Castillo Natacha 1983 series. Attempt to get small, skinny person through current limit, otherwise derig and survey.
Pozo Castillo (Chris Jones)

Valdelafuente / Sobra Valley

  • Re-locate draughting surface entrance on Valdelafuente, close to 80m aven beyond Sump 1 in Cueva del Marniosa,
  • T20 (Sobra Valley) – sandstone sink above Hall of the Mountain King in Cueva del Marniosa,
  • Yorkshire Inlet in Cueva del Marniosa. Exploration of col above aven (also close to T20),
  • Upstream series in Cueva del Marniosa. Large black voids above the streamway,  if leads head to the South this is up the Valdelafuente

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.

  • T554large 100m shaft on the Sierra del a Corta, this requires some digging at the bottom,
  • Al2a 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 NacimientoTerror Firma is only 40m vertically and 200m horizontally from some parts of the surface in the Sierra del a Corta region.

Other

  • Locate and survey General This may be another way into T87 Mazarrasa, bypassing entrance collapse. (most likely T88 Suerte or T89.  T88 draughts strongly at junction inside)
  • 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.
  • Surveying of Nacimiento top entrance series. There are a number of unsurveyed and minor leads in the area,
  • 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.

2017 Summary

Cueva del Nacimiento – Jurassic World – Terror Firma

The ‘final’ aven at the end of the cave was climbed to over 40m, a split in the aven was followed to a new height of 534m above the entrance, but closed down.  The second aven remains unclimbed and is ongoing 

Cueva del Nacimiento – Jurassic World – Pterodactyl Crumble

Another aven at the end of the cave was explored upwards before reaching horizontal passage for another 60m, then finally closing down. 

Cueva del Nacimiento – Death Race 2000 – Joe’s Crack

Initial constriction was passed and the passage continues down another 35m, to head of undescended 12m pitch.  The passage heads under the Death Race chamber, toward the Death Race pitches.

Cueva del Nacimiento – Teeth of Satan – Wet Aven

The Wet Aven was not attempted on this trip, in part due to 2 trips getting lost on the way to the far end and running out of time to climb.

Cueva del Nacimiento – Other

180m of passage found near Death Race passage.

A new aven (+30m) found near P Chamber in Death Race passage, continues.

Cueva del La Marniosa

Sump 1 was dived and the 80m aven beyond was climbed to approx. 47m.  The rock is extremely poor and no obvious continuations could be seen at the top of the aven, using powerful lights.

The Marniosa team diverted attention to trying to dive Sump 2,  an undived sump, discovered in 1987 and unvisited since.  A rather ambitious trip saw two cavers reach sump 2 and allowed one diver to pass sump 2 (30m long t 5m depth) to surface in stream passages.  A further 40m of cave was explored and still continues, before safety concerns forced a retreat.

 Pozo Del Castillo.

Pozo Castillo continues to be surveyed (2km +) and leads explored, attempting to bypass the 1987 snow collapse.  The rediscovery of FT16 and the lower snow levels, allowed further progress in the system, but a sump was encountered at -110m.

Pozo Natacha (a series of pitches in Castillo, rather than a separate cave) was pushed past it’s 1983 limit, down a tight right to the head of a tight 20m pitch.  This pitch head would need serious enlargement before further exploration can continue.

Other exploration

Torca del Carneros was (re)discovered and surveyed.  This lies on La Mesa, above Tresviso, and probably would be connected to caves draining away from Tresviso toward the San Esteban valley.

Fallen Bear was also rigged ready for further exploration in 2018.  The bulk of the cave is a steeply descending ramp, similar to Nacimiento, and contains a number of leads of potential.

Summary:

In total over 2km of cave was surveyed in 2017.  Exploration of Nacimiento continues and has now pushed the height to over 534m from the entrance.  A logistical challenge that is not proving to get any easier, despite fixed camps toward the end of the cave.  Trips to the far end require 4-5 nights of camping, and advanced camps at the far (far) end now need to be considered.  Passing the second sump in Marniosa is a major achievement and unexpectedly has surfaced in passage heading away from Nacimiento and into the mountain, possible towards a hypotheses trunk route that may also feed the upstream sump in Nacimiento.  The rigging of Fallen Bear, and discovery of some new leads, opens up further possibilities of closer deeper systems lying between Nacimiento and the deep potholes high on the mountain.

Pozo Castillo / Segura

Thursday 13th July

Chris and Hannah required a dry way into Segura. Phil responded by rigging a few pitches down Pozo Castillo. Pyro lead us to the start of the ropes from the previous trip. There was a snow plug. We went down it. A few blind pots and cold feet later and a sump was located. Time to find the sun!

Andara (2017)
Andara (2017)

Phil and Pyro started some surveying, as an attempt to connect the dots with Castillo and try and find some missing bypass to the collapse.  Using a Distox and a Nexus 7 with Topodroid (excellent bit of kit!) we started surveying a number of areas; Castillo pitches down to main junction, Castillo crawl and a few further upper series passage.  While approaching the Castillo crawls, Pyro pointed out that he had taken team over the top of the crawl, and that the crawl lead to FT16 probably.  I felt a bit of disappointment, in that I had hoped that the area of the snow plug that the others were working may have been beyond the collapse, but it was looking more likely that they were in Segura 1 or an undiscovered mine area near the surface.  We went into the collapse and I had a quick look, compared to last year the snow appears to have melted further (no much snow in the picos this winter) and exposed more wooden props.  Maybe it just needs some balls of steel and slide down the snow plug at one side, into lower ‘ante-chamber’.  80’s description suggest this is the way forward, possible the collapse is no worse than it ever was, just we are not as hard as the French.

Castillo collapse (2017)
Castillo collapse (2017)

After a quick stop at the snow plug entrance, where we couldn’t hear Hannah or Chris, we exited and located Segura 1.  A short adit, straight onto a wooden winch platform, with nice soft rock and muddy underneath (scary).  This was the same winch platform as can be seen from below, in the snow plug cave.  Again disappointing, but serving to clarify points of entry and conditions.  Exit again and met up with others.

Pyro in FT16 (2017)
Pyro in FT16 (2017)

Friday 14th July

Lots of illness and injuries running through the expedition personnel, myself and Bob headed up to the White House, so that I could survey the ‘new’ snow plug (FT16) and derig.  Bob had no SRT kit and Emma was taking some kit to Fallen Bear  with others before meeting us with her SRT kit (never happened).  Bob and Phil surveyed, Segura 1, Upper Crawl Series and a few little passages. There was still no sign of Emma so I donned my SRT kit and started surveying FT16.  One massive snow plug with various stages of melt, proving tricky and unnerving.  Obviously the survey equipment malfunctioned, requiring a long sit on a patch of snow.  The bottom of the plug suddenly ends in some driven mine passage, containing old mining ladders, before a final pitch down to a sump / flooded level (probably same level as flooded pot in Segura 2.

Started de-rig to eventually greet a worried Bob, who thought I was either buried under snow, or taking too long and he would miss the pub.