Digging as a means of discovering new caves is a well established practice in the karst of the Yorkshire Dales (the area I am most familiar with) and other areas. This can be either digging from surface karst features in the hope of entering passages below, or trying to extend known cave passages by digging through blockages. The scale of some of the digging operations is often not appreciated by non-cavers. Some sites may be dug regularly for years and involve serious engineering work to gain new passage. For example, on Leck Fell in Lancashire it took four years for a group of cavers to excavate nearly 80 metres vertically to gain access to a series of passages already discovered by divers (Walsh 2001). One way of monitoring digging is through reports of finds of animal bones, as these are ubiquitous in unconsolidated cave sediments in the region.
Finds of Animal Bones
Since the 1950s animal remains have been reported from 25 sites in the sporting cave literature (Murphy 2002) and a further 8 sites are known but no written record of the discovery of animal remains was made (Murphy 2003a). Sites which have produced vertebrate remains described in the scientific literature are listed in Chamberlain (2002). Proximity to the road and rail networks has been a significant factor in determining which sites have received scientific attention, whereas surface accessibility has not deterred sporting cavers. This suggests there may be many more sites in the area with a much wider geographical spread than is indicated by a study of the scientific literature.
The Recovered Bones
However, there are important contrasts between the sites recorded from the caving and scientific literature. The bias of the caver records towards large animal bones is mentioned in Murphy and Chamberlain (2003). This probably reflects to some degree the probability with which finds are noticed and reported by sporting cavers. While this is certainly a valid explanation, the limitations posed by the use of head mounted lighting systems by cavers are not generally appreciated by non-cavers. Even in regularly visited sites bones have been passed by cavers for many years before being noticed. For example, although bones had already been recovered from the River Junction area of Kingsdale Master Cave (a very popular caving trip for novices), a horse skull jammed beneath a rock ledge next to the main cavers path was only noticed in 2002 (Murphy 2003b). Another contrast is in the age of the material recovered. The majority of the caver recovered fauna is probably, at least in part, of domestic or agricultural origin. This may reflect the lack of older deposits at the sites, though the occasional record of older faunas suggests this is unlikely. Cavers may also preferentially select digging sites where active deposition has occurred in recent times.
Cave Digging Techniques
A third possible explanation results from the contrasting aims of a cave exploration dig with those of an archaeological dig. The approach of cavers is to try and minimise the amount of material removed in order to gain access to open passages. This is not only to minimise the physical effort involved but because opportunities to dispose of debris from the dig site are often limited. In a filled horizontal passage this means digging against the roof as this will probably be where the blockage is the shortest, the fill least consolidated and the probability of intersecting any unfilled roof voids the highest. When digging a filled shaft the cavers will follow a solid wall rather than trying to go down the centre. This allows bracing of the dug shaft and will hopefully reach the top of any ongoing passage with the least volume of material needing to be moved. The strategies employed by cavers mean that in a horizontal passage the cavers are concentrating on removing the youngest sediment deposited in the passage and in a vertical shaft fill the oldest deposits at the base of the filled shaft will hopefully not need to be disturbed. This contrasts with the activities of archaeologists whose aim is to unravel as much of the history of the site as possible. As a result the recovery of animal bones by cavers must be taken as an indication of the potential of a site to contain older remains and not be judged as archaeologically unimportant solely on the basis of the age and origins of the bones submitted for identification.
The two cave sites in the Craven area which have produced Ipswichian (OIS 5e) faunas are both known as a result of major excavations. In the case of Raygill Fissure, Lothersdale, the cave was exposed as a result of limestone quarrying and the fauna were recovered as the quarry face moved through a filled off-vertical shaft. The Ipswichian fauna were at the base of the completely sediment filled shaft from the base of which a horizontal passage led off (Mial 1880). The site appears to have been a pitfall trap in pre-last glacial times. In the case of Victoria Cave, the Ipswichian strata was only discovered as a result of the deliberate sinking of a number of shafts in the floor of the cave as part of a large scale archaeological dig (Tiddeman 1872). In neither case was there any evidence of the presence of these older deposits before quarrying or excavation took place. This shows the possibility of there being more such sites in the Craven area and any sites identified as containing animal remains by cave exploration activity must be considered as potential repositories of older deposits.
In conclusion, digging as a means of discovering new caves by sporting cavers has made a significant contribution to our knowledge of the archaeological resource of caves in the Yorkshire Dales. The strategies employed by cavers in order to dig through material blocking both horizontal passages and vertical shafts tends to limit the disturbance to the youngest layers in the deposit and has contributed to the bias apparent in the caver records towards more recent bone assemblages. This current paper has concentrated on the Yorkshire Dales, and as a review of currently available evidence offers an initial assessment of the impact that recreational cave digging has on archaeological deposits. It would suggest that such digging activities should not necessarily be seen as a problem by the archaeological community or the statutory bodies responsible for conservation as the damage caused, on the whole, would appear limited. It should instead be seen as an opportunity to increase our knowledge of this often neglected field of archaeology.
Chamberlain, A. T. 2002. A gazetteer of non-human vertebrate remains from caves in the Yorkshire Dales described in the scientific literature. Capra 4 available at-
Mial L C 1880. Raygill Fissure, the cave and its contents. Proceedings of the Yorkshire Geological and Polytechnic Society 7: 207-8
Murphy, P. J. 2003a. A gazetteer of non-human vertebrate remains from caves in the Yorkshire Dales for which there is no record. Capra 5 available at -
Murphy, P. J. 2003b. More of the Kingsdale Horse. Speleology 2: 5
Murphy, P. J. 2002. A gazetteer of non-human vertebrate remains from caves in the Yorkshire Dales referenced in caving club journals and allied literature. Revised version 2004. Capra 4 available at –
Murphy, P. J. & Chamberlain, A. T. 2003. The bone caves of the Yorkshire Dales. Speleology 1: 11
Tiddeman, R. H. 1872. Discovery of extinct mammals in the Victoria Cave, Settle. Nature VII: 127-8
Walsh, A. 2001. The quest for a dry way. Descent 159: 20-22
P.J. Murphy. Department of Earth Sciences, University of Leeds, Leeds, LS2 9JT, U.K.
Murphy, P.J. 2004. Cavers, Digging and Archaeological Finds in the Yorkshire Dales. Capra 6 available at - http://capra.group.shef.ac.uk/6/cavedigging.pdf