Langcliffe Pot

Coordinates: 54°13′16″N 2°24′07″W / 54.221°N 2.402°W / 54.221; -2.402

Langcliffe Pot is a cave system on the slopes of Great Whernside in Upper Wharfedale, about 2 km SSE of Kettlewell in Yorkshire (UK NGR SD996711), and actually some 20 km NNE of Langcliffe village. The cave entrance is at an altitude of 470m. The system has a total surveyed passage length of about 10 km, and a depth of only a little more than 100m. It was explored originally in 1936 and 1954 by the Craven Pothole Club (CPC), extended in 1968 by the Yorkshire Underground Research Team (YURT), and in 1968-70 by the University of Leeds Speleological Association (ULSA[1]).

Description

The Oddmire entrance drops below a limestone slab at the bottom of an otherwise unremarkable shallow shakehole north-east of Fox Scar. A pitch of 30m leads to a traverse, then the start of 200m of wet crawling, Craven Crawl, the termination of the cave until 1968.[2][3] Beyond Number One Junction, Stagger Passage leads 600m to Hammerdale Dub, and a junction with still larger passage continuing downstream. Some 1500m of streamway interspersed with boulder obstacles, Langstrothdale Chase, ends in a bedding plane crawl leading to Boireau Falls Chamber, 20m in diameter and 6m high, where the stream reappears and cascades into the boulders flooring the chamber. A complex boulder choke leads to a 20m pitch dropping into the Nemesis chamber. A massive collapse region, a tight and navigationally complex boulder choke, leads to Gasson's Series,[4] initially high streamway, descending past Poseidon Sump and on into a procession of fine rift passage and chambers of the Agora, before turning east into Aphrodite Avenue, a handsome canyon with gour pools, and the Silver Rake. The system comes to an end at a wall of sand and boulders, which can be bypassed to a smaller descending passage reaching a sump.

Notwithstanding its limited depth, a trip into the far reaches of Langcliffe Pot is still rated as one of the more serious undertakings in British caving. A detailed passage description and survey is given in Northern Caves.[5][6] A survey in relation to the other caves of the Black Keld drainage system, and a detailed discussion of the geology and hydrology, is given in Limestones and Caves of Northwest England, Chapter 22.[7]

Geology

The surface region displays the classical scar morphology of the Great Scar Limestone. The higher beds, of Yoredale Limestones, form wide benches separated by steep scars, and the highest of these, the Middle Limestone bench, is pitted with shakeholes and partially covered by peat, sphagnum bog, clay and sandstone debris. The majority of the Langcliffe cave system is developed within the Middle Limestone series, with visible horizons of shale, chert and fossil bands. The Nemesis Pitch cuts through an otherwise impervious layer of shale to enter the Simonstone Limestone, while Gasson's Series below is totally developed within the Hardraw Limestone. The Silver Rake is named after the vein of the North Mossdale suite which controls the direction of passage below the Agora.

Hydrology

The catchment area of Great Whernside, some 20 km2 in size, is a gathering ground for water entering the Langcliffe system, as well as the largest stream of the area which sinks into the ground at Mossdale Scar. Beneath Mossdale Scar, several entrances amongst a chaos of boulders unite close to the entrance to enter Mossdale Caverns, a 10 km long complex system of underground passage. The Mossdale sink takes an average flow of 100 litres/sec, and resurges at Black Keld.[8] Langcliffe Pot, which also feeds the Black Keld rising, terminate some 180m above, and several kilometres distant from it, leaving many questions about its detailed hydrology beyond the present limit of exploration. Surface sinks above Gasson's Series, for example, do not enter the Langcliffe system itself, but are diverted into separate cave systems by the layers of impervious strata above the Hardraw Limestone. Langcliffe Pot demonstrates the scale and complexity of the integrated cave system which must exist below the flanks of Great Whernside, a future challenge for sporting cavers and speleologists.

See also

References

  1. ↑ University of Leeds Speleological Association ULSA
  2. ↑ Rogers, M., Langcliffe Pot, ULSA Review, No.5, pp7-15, 1969
  3. ↑ Some of the early exploration is described in David Yeandle, The Adventures Of Another Pooh: Caving Explorations and Escapades, AuthorHouse, 2002
  4. ↑ Yeandle, D., Langcliffe Pot: Gasson's Series, ULSA Review No.8, pp15-19, 1971
  5. ↑ Northern Caves, Volume 1, Dalesman Publishing, 1972
  6. ↑ see also http://www.northerncaves.org.uk/
  7. ↑ Limestones and Caves of Northwest England, A.C. Waltham (ed.), David & Charles, 1974
  8. ↑ Myers, J.O., The Mossdale Problem: The Problem of the Underground Water Flow, Trans Cave Research Group, No.1/4, pp.21-30, 1950
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