Karstbase Bibliography Database

Four widely separated groups of phreatic network caves below the moors separating Swaledale and Wensleydale in the Yorkshire Dales have previously been reported, including a group of five closely-related systems accessed through the levels of Devis Hole Mine. Further exploration has now uncovered four more phreatic systems, including another network maze in Devis Hole, the Horn's Workings Cave Series. While similar in geomorphological structure to the earlier discoveries, this Series is distinct in having, in addition to horizontal passages, a number of shafts reaching towards the base of the Main Limestone beds in which all of the six cave series reside. This may be due to the presence of a syncline affecting the strata in this area of the mine, which would have provided a natural drainage route and might also have allowed joints to open, thus enabling vertical shafts to develop. The Horn's Workings Cave Series has been worked intensively by 19th century lead miners, and comparison of a recent survey of Horn's Workings with one made by the miners in 1857 indicates the high degree of accuracy achieved by the earlier surveyors. Two of the other recently discovered systems, Smithy Level Caves and Summer Lodge East Level Cave, are also accessed through old lead mines. Both display classic phreatic features modified by later vadose activity. The final new discovery is Shivery Gill Pot, a small extension of the previously examined group of Sod Hole Gill Caves. The nature of the range of phreatic systems now known to exist beneath the Swaledale-Wensleydale surface watershed implies that numerous other network caves might exist in the upper part of the Main Limestone in this region. These beds extend over a distance of more than 20km from west to east, but they are at outcrop only locally, so if such network caves are present they will probably only be discovered and accessed from the old lead mine workings that are a major feature of this part of the Dales landscape.