By Charlie Self
This is an unusual issue of Cave and Karst Science in that the front and back cover photographs relate to the Editorial rather than to any of the papers. The front cover shows entrances to what may be the world's highest relict trunk cave passages (in China), while the back cover shows several pictures of the Porcellanous Bed - a significant marker bed within the limestone of the Yorkshire Dales and the subject of a recent BCRA field meeting. The issue itself contains six papers, four of them relating to the north of England. Also, in the "Forum" section, there is a detailed review of the newly published Caves and Karst of the Yorkshire Dales Volume 1.
Malham Tarn is scientifically interesting because it is a marl lake, i.e. more than 50% of the inorganic part of its sediment is calcium carbonate. The sediment also contains the fossil remains of diatom frustules (the thin silica shells of algal cells). The study compares the algae living in the lake today with algal fossils found in a sediment core taken from the bottom of the lake. Since the end of the last Ice Age, when marl sediments began to accumulate, there has been little change in the algal fossil record until the top part of the sediment is reached. This seems to coincide with an artificial raising of the water level in the lake (in 1791 to improve the fishing), which caused an increase in the amount of nutrients in the water and so changed the balance of algal taxa (types) living in the lake.
In the northern part of the Yorkshire Dales, the land is underlain by rocks of the Yoredale Group which comprise repeated cycles of limestone overlain by shale, then sandstone and commonly a thin bed of coal at the top. The most substantial of these limestone beds is the Great Limestone and it contains the best of the known caves. There have been three major dye tracing studies in the Northern Dales: in the late 1950s, the late 80s/ early 90s and this present study. The results of all are collated here and confirm the longstanding belief that some of the underground water routes pass beneath the Swaledale/ Wensleydale surface watershed.
A recent caving expedition to Vietnam discovered a calcite version of China's famous Terracotta Army. More than a hundred stalagmite-like formations of similar shape and height cluster behind old gour dam barriers that now hold little or no water. The authors hesitantly conclude that these formations are raft cones that grew when the pools were full. A raft cone forms when dripping water sinks (in the same spot) calcite cave rafts that develop on the surface of gour pools.
The paper includes photos of similar raft cones in an American cave and quite dissimilar tufa towers from a hydrothermally-fed lake in Africa. An apparent problem for the authors is the fact that their cones are so steep-sided that the cave rafts must sink almost vertically down through the water column without any side-slip. My take on it is that this problem disappears if you remember that the cones and their gour dams are growing simultaneously. If the tops of the cones stay close to the pool surface, the rafts will have very little distance to fall.
This is a review of research into material from the most important cave site in Jamaica for Late Pleistocene terrestrial fossils. There is no evidence that these animals lived in the cave, and the probability is that they were washed in during tropical storms. The site is particularly rich in land snails, with 62 species identified. A relatively low proportion of the fossil snail species still live in the vicinity of the cave, which suggests a change in climate between the Late Pleistocene and the Present. The paper also records the presence of 13 species of arthropods (millipedes, insects and crustaceans) in the fossil deposit, but notes that the microscopic ostracod (seed shrimp) fauna remains to be described. Perhaps surprisingly, the terrestrial vertebrate remains (amphibians, reptiles, birds and mammals) have not yet been studied in detail and only bats and rodents have been documented fully.
Sub-vertical phreatic dissolution cavities, known locally as gulfs, were encountered by miners in historic times as they worked the mineral veins in this south-eastern part of the Yorkshire Dales. These gulf cavities are completely filled with sediments: limestone, clay, sand and material derived from the mineral veins. The presence of chlorite in the infill is a mystery since it is not known to occur locally. The authors suggest that this mineral may have been brought into the area by glacial ice, in which case the gulf sediments are (at least in part) reworked glacial deposits. The mineral veins are thought to be of Late Carboniferous to Late Permian age, so the gulfs (which contain reworked mineral deposits) must be younger than this. A suggestion that the gulfs may have developed from ancestral (i.e. pre-mineralisation) dissolution voids does not explain why these then grew in size instead of filling up with minerals. The authors themselves note two horizontal caves that clearly belong to an early phase of dissolution since they have the same mineralisation as the ore veins. The paper ends with a review of large karstic cavities in other caving regions. A number of similarities are apparent, but the sediment infill of the gulfs is not matched elsewhere.
Organised caving in this country did not really exist before the 1890s. Among the pioneers were the Yorkshire Ramblers' Club (Leeds, 1892), The Kyndwr Club (Sheffield and Derby, 1895) and the Rucksack Club (Manchester, 1902). These were not dedicated caving clubs, but societies that included caving and climbing in their activities. By far the most successful of these was the Yorkshire Ramblers' Club, who have a spectacular record of discovery, exploration and survey in the caves of the Yorkshire Dales.
So why did the Rucksack Club make no major cave discoveries in their own local karst area, the Peak District? Their records note many collaborations with other clubs on sporting trips, which suggests that Rucksack members were competent cavers but perhaps not interested in the hard work of exploration and survey. It is worth noting that three of the "hard men" living in the RC catchment area chose to be YRC members. Of the Kyndwr Club, the paper says little except that their members were quite hard but the club folded after only ten years (perhaps over personality differences). After the Second World War, clubs devoted exclusively to caving became the norm and more general outdoor societies like the Rucksack Club dropped caving from their activities.
Though not strictly relevant to this paper, it is perhaps worth considering what makes a successful caving club. For a minority sport which requires the training of new members, continuity of membership and long term projects would appear to be the key. This usually means research projects in some form (exploration, survey, science …. whatever), because young sport cavers often give up after two or three years unless their interest has been captured on a deeper level.