Resurgences

In the caves section there examples of rivers taking an underground route through limestone. The rivers flow downwards towards the water table; below the water table, caves are flooded, but the rivers continues to flow even here because of the high hydrostatic pressure.

The water is forced to move towards areas of low hydrostatic pressure, and this is generally at a spring line, where underground rivers return to the surface — 'resurgence'. As they do so, the water is still mineralised, and at the resurgence partial evaporation will take place and in some cases lead to the precipitation of tufa (like at Mother Shipton's Cave).

White Scar cave system

White Scar Cave

White Scar Cave in Chapel-le-Dale is an example of resurgence. Water that drains from the uplands on the western side of Ingleborough is taken underground through swallow holes at Crina Bottom into a cave system that stretches for at least 6.5 km. It is seen at the surface again in Chapel-le-Dale, a short distance from the White Scar Show Caves.

A little upstream from the resurgence is a large cavern called Battlefield Chamber with stalagmites over 350 000 years old. Between this chamber and the resurgence, the floor of the cave is composed of Ordovician slate. The waters from Ingleborough moves readily through the faults, joints and bedding planes of the limestone and along a long, gently sloping, vadose streamway, but it is the impermeable slate that stops further downwards movement and directs the water towards the resurgence.

Keld Head resurgence

Keld Head

High above Kingsdale there are many streams that flow over the grits that cap the Pennines in the region, and then disappear through a number of dolines including Jingling Hole on the western side of the valley and Growling Pot to the east. They flow through vadose cave systems to about the level of the Kingsdale Master Cave, which is close to the water table, but from there, many of the passages are flooded (the phreatic part of the cave system). All of the underground rivers converge and eventually return to the surface at the Keld Head resurgence, in Kingsdale.

Turn Dub and Footnow's Hole resurgences

Footnow's Hole exit for water from Alum Pot

The main drainage system on Simon Fell once flowed down Alum Pot, but the drainage pattern has changed so that only a small stream now falls down the swallow hole. Having tumbled down the 70 m high falls, the river follows a series of caves to remerge at the resurgence at Turn Dub and Footnow's Hole.

Malham Cove resurgence

Malham Cove is a huge natural limestone cliff. During the retreat of the ice caps and release of huge amounts of water at the end of the last ice age, it would have been a spectacular waterfall. But the valley above Malham Cove is now dry and the river takes an underground route. The cave system that it uses is mainly unknown, but it resurges at the foot of the cliff at Malham Cove, where a small stream called Malham Beck rises from a submerged cavern.

Resurgence at Malham Cove
Malham Cove waterfall