The distinctive shape of Ingleborough is due to the local geology, a broad cap of millstone grit atop a broader plateau of carboniferous limestone. Streams running off the millstone grit meet limestone rock further down the slopes where they disappear underground, falling into deep potholes and caverns such as those at Gaping Gill on the moors above Clapham and Alum Pot near Selside in Ribblesdale.
After passing through complex underground cave systems these stream emerge at resurgence caves lower down, often at points of geological unconformity where the limestone lies on top of non permeable rock strata. In the case of the Gaping Gill system, the main resurgence occurs at Beck Head Cave in Clapdale - adjacent to the main entrance of Ingleborough Cave (to which it is connected).
Other Ingleborough websites
The following (externally maintained) websites may also be of interest:Eagle Intermedia Yorkshire Dales website when making your enquiries.]