Long Kin East Cave - Rift Pot System
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| Long Kin East - Rift Pot System | |
|---|---|
 A caver descending the entrance pitch of Rift Pot | |
  | |
| Location | Ingleborough, North Yorkshire, England |
| OS grid | SD 7624 7307 |
| Coordinates | 54°09′11″N 2°21′55″W / 54.152966°N 2.365236°W |
| Depth | 116 metres (381 ft) [1] |
| Length | 1.5 kilometres (0.93 mi) [1] |
| Elevation | 411 metres (1,348 ft)[1] |
| Discovery | 1904 |
| Geology | Carboniferous limestone |
| Entrances | 5 |
| Hazards | verticality, water, boulders[1] |
| Access | Booking required |
| Cave survey | On Cave Mapper |
The Long Kin East Cave - Rift Pot system is a limestone cave system on the southern flanks of Ingleborough, North Yorkshire in England lying within the designated Ingleborough Site of Special Scientific Interest.[2] Long Kin East Cave starts as a long meandering stream passage but then plummets down a 58-metre (190 ft) deep shaft when it meets a shattered fault into which Rift Pot also descends. At the bottom, the stream flows through some low canals and sumps, to eventually emerge at Austwick Beck Head in Crummackdale.
The main entrance to Long Kin East Cave (54°09′11″N 2°21′55″W / 54.152966°N 2.365236°W) is where a small stream sinks into a deepening fissure in a small exposure of limestone rocks located in an extensive area of moorland. The fissure gains a roof and morphs into a walking-sized meandering stream passage, passing an alternative dry entrance at the first corner. After 216 metres (709 ft) the passage passes below a walled-off pothole (54°09′06″N 2°21′57″W / 54.151669°N 2.365922°W) where daylight enters. After a further 43 metres (141 ft) an ascent up a slope of rocks leads to the bottom of the Long Kin East Pot entrance - a 4-metre (13 ft) deep shaft (54°09′05″N 2°21′56″W / 54.151351°N 2.365672°W).[1]
A route through the boulders at the bottom of the Long Kin East entrance drops into the continuation of the stream passage. This continues for a further 216 metres (709 ft) where it starts to descend a succession of small cascades and pitches. A final cascade leads into a chamber overlooking a 58-metre (190 ft) deep shaft, at the bottom of which is an elongated rift chamber formed within a fault.[1] Upstream ascends a boulder slope where various routes from Rift Pot enter. Downstream, a mud slope drops into a stream passage, which continues upstream as a series of oxbows that reappear in the chamber. The stream continues low and wide to a junction. Downstream continues to a 20-metre (66 ft) long sump that emerges in a 25-metre (82 ft) long canal at the end of which is a second sump. This has been explored for 120 metres (390 ft).[1][3] Upstream from the junction, a wet crawl reaches some gour pools in a walking-sized passage, before continuing as a crawl which chokes just to the east of Jockey Hole.[1]
A few metres back from the chamber overlooking the main pitch, a bedding traverse in the roof of the passage leads to a high chamber overlooking the shaft. A boulder slope can be followed round the chamber to a rock bridge crossing the rift. A short descent from The Bridge leads into Rift Pot (see below).[1]
The Rift Pot entrance (54°09′05″N 2°22′03″W / 54.151379°N 2.367571°W) is located on the same major fault as is seen underground. The 60-metre (200 ft) deep shaft of Jockey Hole lies 65 metres (71 yd) further up on the same fault. The entrance shaft drops 34 metres (112 ft) into a large chamber. The chamber is blind to the north, but an ascent of boulders on the south side climbs up into one end of the enormous fault chamber, at the far end of which enters Long Kin East Cave. Two small pitches over boulders lead to a boulder platform below The Bridge, from the top of which a traverse leads back into Long Kin East Cave. From the platform, a variety of routes may be descended to the floor of the chamber, 60 metres (200 ft) below, between the various jammed boulder platforms that partition the chamber. One route which does not descend through the boulders is the 68 Series, which start as a bedding plane passage leading off from a boulder chamber 37 metres (121 ft) above the floor. This complex of passages is about 122 metres (400 ft) long, one branch of which descends a succession of small pitches to finish at a window overlooking the bottom of the chamber some 9 metres (30 ft) above the floor.[4]
Both Rift Pot and Long Kin East Cave have been equipped with resin P-hangers allowing cavers to follow a number of different routes to the bottom using single rope techniques.[5][6]
Geology and hydrology
The Long Kin East system is a solutional cave formed in Visean Great Scar limestone from the Mississippian Series of the Carboniferous period.[7] The entrance to Long Kin East Cave is close to the limestone margin where a small stream, with a mean flow of about 30 litres per second (6.6 impgal/s), sinks into the limestone.[8][9] The entrance passage is a meandering vadose canyon which descends gradually following the local southerly dip before reaching the main shaft. This, and Rift Pot, are formed in the breccia and shear zone of a major fault.[8][9] Exploration of the phreatic stream passage at the bottom of the shaft has reached a point which is 11 metres (36 ft) above and about 2 kilometres (1.2 mi) distant from the resurgence at Austwick Beck Head in Crummackdale.[10]