By Charlie Self
This issue of Cave and Karst Science contains six short papers plus the abstracts of the 6th Cave Technology Symposium, held at Priddy in Somerset. Also included is a report on a joint BCRA and Quaternary Research Association field meeting on the subject "Cave archaeology and karst geomorphology in north-west England".
The sandstone caves of Table Mountain and the Cape Peninsular, South Africa have an exploration history that goes back three centuries. The caves are within easy reach of the city of Cape Town but they are not very long, not very pretty …. and not as well documented as they should be. This short paper describes the exploration history of the caves from 1709 up to the present day. But this is no dry documentary record: the author seamlessly adds contemporary gossip into the paper, to bring the explorers and their histories to life.
Wenlock Edge and the nearby View Edge are two small escarpments of Silurian limestone in the western part of the English midlands. There are many fissures in the scarp faces but no enterable caves. Small scale karren, a few small dolines and spring-fed valley systems indicate that this is a fluviokarst landscape and the water chemistry of the springs is similar to that of other British karst regions …. so yes, this is karst. Does anyone know of a smaller and even more obscure karst terrain in England?
The high quality iron ore deposits of South Cumbria are of speleological interest because they were emplaced in ancient natural (palaeokarst) cavities. At Hodbarrow Point, there are clearly defined dissolutional scallops on the cavity walls beneath the hematite. The size of the scallops indicates a water velocity of just over 1 metre per second, consistent with flow in the vadose zone of a karstified aquifer. The origin of the iron-bearing ores and the date of their emplacement are still uncertain, but the evolving consensus is that they are very old. Since the palaeokarst cavities must be even older, they probably formed during the late Carboniferous/ early Permian period, when earth movements elevated the region above sea level.
This paper was inspired by the photograph on the front cover of the last issue of Cave and Karst Science, where the caption claimed "…. Batu Caves are possibly the most-visited karst locality in the tropics". There are problems with the definition of "locality" (a single site, or a local area) and there are problems with the accuracy of reported visitor numbers, but the economic and environmental effects of tourism in tropical landscapes are considerable. The paper gathers the available evidence for the most popular "localities" and concludes that the Temple Cave at Batu probably is the most-visited individual karst site. However, visitors to the city of Guilin in the karst landscape of southern China are far more numerous.
Changing agricultural practices, forestry and construction activities can lead to increased soil erosion and the deposition of fine sediments in the aquatic environment. This has an effect on small invertebrates that inhabit the saturated interstitial spaces beneath and adjacent to streams and rivers. This includes stream passages in caves.
A laboratory experiment was constructed with water rising through an artificial river bed and also descending through the bed, to mimic what happens in natural streams. The test subjects were common freshwater shrimps which live in the gravel beds of flowing streams. In open gravel, the shrimps congregated at the top of the sediment in downwelling conditions and at the bottom in upwelling, because these areas have the greatest hydraulic flow. The same happened when a layer of river sand was put on top of the gravel, because water movements created pathways to and from the deeper sediments. In experiment 3, several layers of river sand within the gravel column clogged up these pathways and kept most of the shrimps in the upper part of the sediment. These results may seem predictable, but this is how the "scientific evidence" is gathered on which future environmental decisions are made. We need more experiments like this.
A diary was recently discovered in the attic of a Devon farmhouse that had previously belonged to descendants of Walter Sherwill, the diary's author. Sherwill was an East India Company officer who whilst on long leave explored the countryside of Cape Province (South Africa) and also visited Cango Cave. He sent a report of his visit (which we now know was copied from this diary) to a local South African newspaper, where it was published. This was the first description that was readily accessible to residents and visitors to Cape Province and brought considerable attention to the cave. The report was reprinted many times during the following years in the Cape almanacs (an annual publication for the Province), which further spread the fame of Cango Cave.