Nidderdale

Geology

The caves of Upper Nidderdale are extensive, impressive and have unique characteristics within the UK[2][3].

The Goyden cave System

•	The cave system is largely developed beneath a major valley floor with many of the passages still beneath a cover of Millstone Grit or Upper Yoredales. (Ford 1963)

•	It has developed across a number of geological structures including an anticline and several faults (Ford 1963)

•	In Manchester Hole vadose downcutting has breached the base of the limestone and cut into the underlying strata (Ford 1963)

•	Studies have confirmed that wind action on the Scar House Reservoir when full or nearly full can create significant overflow causing serious flooding of the caves further down the valley.(Gunn 2006)

Nidderdale is at about the same altitude as Wharfedale and separated by just one ridge including the summit of Great Whernside. The Great Scar limestone so evident in Wharfedale is nowhere to be seen in Nidderdale as the easterly dip of the Pennine anticline carries it well below the floor of this small valley. The carboniferous limestone that is visible is the Yoredale series with almost all the cave system developed within the narrow band (maximum of 40m) of the Middle Limestone. The limestone outcrops in three areas, three inliers: one to the north including the cave sinks of Manchester Hole and Goyden pot, one really small outcrop 2-300m further south including the New Goyden pot, and one nearly 2km further south including the Nidd Head rising. The most northern inlier of limestone is cut off from the limestone beds at Scar House Reservoir by a large east-west boundary fault. The most southern inlier of limestone is cut off from any continuation by a fault just north of the head of Gouthwaite Reservoir. In between these bounday faults the limestone generally gently dips towards the south except in the vicinity of faults most prominent in the area around New Goyden pot. Each inlier is separated on the surface by the base of the Grassington Grit or Upper Yoredale series. The cave system is contained within the Middle Limestone and chiefly developed along the shale partings of the bedding planes. The faults frequently mark the position of the sumps with typically significant open passage between faults. The joints and faults only give rise to local vertical features suggesting that certain bedding planes have been preferred in the development of the cave regardless of level. It is clear that once the erosion of the Upper Nidderdale valley had exposed the Middle limestone at Limley and south of Lofthouse then the 60m fall would create a significant hydrostatic pull to develop an artesian flow. After this uncovering of the Middle limestone in the Pleistocene period the cave development was clearly more rapid than the valley deepening by the surface river. This has resulted in one of the youngest cave systems in the UK being one of the largest at a shallow depth beneath a valley floor most of which still retains a gritstone cover.It did surprise early explorers to find long sections of large passage such as Goyden’s and New Goyden’s main stream passages and large chambers such as Main chamber in Manchester Hole and Goyden pot. Distinctive fossil and chert beds so common a characteristic of the middle limestone are well exposed in the caves and provide some impressive examples of Gigantoproductous beds, crinoid fragments and colonial coral.

References

1.	^ T.D. Ford (1963) CRG Vol 6 No. 2

2.	^ J. Gunn(2006)

The How Stean Gorge and Eglin’s cave System

•	The How Stean Caves are a remarkable large-scale example of rejuvenation causing abandonment of an underground drainage route in favour of a surface course, contrary to normal development. The Lofthouse inlier, the most southern and largest of the three limestone inliers contains the How Stean caves, the caves near Lofthouse; Nidd Head risings and rising for the Egiln system; and the Blayshaw Gill pots. The limestone of the two northern inliers dip gently south with the valley whereas the limestone of the Lofthouse inlier even more gently east alongside the How Stean Beck running generally south-east. The How Stean Beck is a tributary to the river Nidd, which flows through an impressive limestone gorge, How Stean gorge in places 15m deep. Running parallel with the gorge on its north side is the Eglin’s cave system with well over 2km of passage. From the gorge Eglin’s runs north-west for 1.3km and Low Egin’s runs south-east for 900m forming a single linear vadose system. Tom Taylor’s cave (180m long) between both caves has connections with both all be they too small for anybody to traverse. The small underfit streams that now traverse the system clearly are not large enough to have formed the system. The river Stean would have entered via North-West Frontier system opposite Waterfall cave but was later captured by the rejuvenation of the gorge during the Pleistocene period. A local collapse of the original entrance may well have assisted this process. The surface valley now carries the river and has created a gorge with floor some 10m below the cave system.

References Outlying karst areas of the northern pennines, Nidderdale caves by A C Waltham

Hydrology
The Hydrology of the Goyden System

The water flowing from Scarhouse reservoir flows east and then south with the valley. Not long after turning south it meets the first of several fissures in the river bed a few metres north of the entrance to Manchester Hole. The water entering Manchester Hole via these fissures flows below and past the main entrance and along the fine main stream passage. Debris and vegetation along the roof here suggests frequent flooding but in fact was deposited before the Scarhouse dam was constructed. The stream flows through boulders at the base of the large breakdown chamber. This breakdown has been helped by the periodic incursions of streams opened and then closed by flooding on the surface. One such incursion in the 1990’s caused a large section of the mud bank within the chamber to collapse. The stream flows out from the boulders along a large passage to where the dip in the roof brings it to a crawl. After the crawl the stream flows along a high but narrower passage to the duck. A high level passage in this section leads down to the static sump that connects with Pillar pot in Goyden pot. The end of the sump is blocked by boulders and silt but would in the past have connected with Old year passage in Goyden pot. Flooding caused by more water entering Manchester Hole and pooling from the Goyden pot can cause the area from the crawl to duck to flood extremely fast especially with incursions of flood water opening up old inlets. The stream, after the duck, flows along a short section of passage to sump 1 through to Divers chamber and onwards to sump 2. Water exits sump 2 to flow along Lesser Stream passage to the cascades. In flood the fissures of Manchester Hole are quickly overcome so that water flows on to Goyden pot main entrance. The river flowing into Goyden main entrance flows out of the first windown into the main chamber and joins the normal flow from Manchester Hoel at the cascades. The combined water flows along an impressively sized river passage to the downstream sumps. A series of nine sumps take the water through to New Goyden. In flood time sump 7 due to its restricted nature causes water to back up and enter a passage high up between sump 6 and 7. The water flows through Toad Hall and the 30m sump to join the smaller stream from New stream sump Goyden pot on its way to Main inlet in New Goyden. The combined waters in New Goyden flow through nine sumps so far explored and then a 1km gap yet to be explored to the Nidd Head risings. There are three risings the NW rising being the main one with associated Tributary and SE rising.

The Hydrology of the Eglin’s System

The small streams that enters Eglin’s hole quickly combine to flow through the length of the cave and then through to Low Eglin’s. At the far end of Low Eglin’s the stream disappears through a too narrow slot to follow to then resurge through the Nidd alluvium south of the village of Lofthouse. To the left before the exit slot in Low Eglin’s is a muddy passage which would have led to the old resurgence possibly Canal cave or a cave nearby now blocked. The small stream that has now invaded Canal cave exits the cave into the surface riverbed normally dry along a trench to sink again in a cave opposite. Clearly the cave has been truncated by the erosion of the valley. The water sinks in at least three places here to rise again at the resurgence in the alluvium.

Caves

 * Manchester Hole
 * Goyden Pot
 * Guscott Pot
 * Frog Pot
 * New Goyden Pot
 * Nidd Head Risings

Howstean Caves
 * Eglin's Hole
 * Low Eglin's