Hello everyone!
I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")
There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found:
Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum
The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...
Did you know?
That Darcy-Weisbach equation is an empirical equation given as which states that in contrast to laminar flow, the average volumetric discharge of flow is directly proportional to the square root of the driving force and that the friction loss is equal to the hydraulic head [5]. note: q=discharge, a=crosssectional area, r=hydraulic radius of the conduit, g=gravitational acceleration, f=some friction factor, dh/dl=gradient, and i have attached a negative sign to indicate that ground-water flow occurs in the direction of decreasing head. in most instances, a negative sign is not included because it is not possible to take the square root of a negative number.?
The Transvaal Karst is a world important example of a Karst developed on a very old dolomite. Its unique character is due to the composition of the rock and history of development. The dissolution of the dolomite is interesting and has an important effect on the character of the caves developed. The caves preserved in this area include the longest known in South Africa and are perhaps among the largest dolomite systems known in the world. They are very old and in some cases contain important palaeontological deposits (Australopithecine fauna). The caves to various degrees are in a state of de-generation, having been exposed for a very long period above the water-table. For the greater part of the Karst area, aggressive vadose waters, and long exposure has resulted in the accumulation of a thick covering of residual material. The plateau-like geomorphology and low rainfalls has prevented physical erosion and significant removal of this debris from the land surface. The caves themselves are often characterized by collapse and in general lack of formations. Massive calcite formation in the caves is usually partly or nearly completely redissolved and are relics of past colder climatic periods with winter rains. Formations active now are small, usually delicate and often due directly to evaporation. The heavy mantle of residual debris preserved under some of the more ancient of South African landsurface relics (the African Surface) poses a serious economic problem of stability, with mans' utilization of the environment. A greater understanding of the Karst, its evolution and properties is thus of considerable practical importance.
This paper reviews critically some recent work on the systematics of subterranean Crustacea, in particular Jakobi's work on the Parastenocarididae (Copepoda), Serban's work on the Bathynellidae (Bathynellacea, Syncarida) and Schminke's revision of the Parabathynellidae (Bathynellacea, Syncarida). Is is pointed out that three different approaches have been adopted in each of the three cases and advantages and shortcomings of each of them are analysed. Finally descriptions are given of two new genera of Parabathynellidae, Afrobathynella gen. n. and Nunubathynella gen. n., from a locality near Port Elisabeth (South Africa).
Caves of South Africa - A general description of the caves of South Africa is given. This includes a brief account of caving techniques and aspects of research on the geology, hydrology, morphology and mineralogy of the caves. Although caves systems are well developed in the country, a surface karst morphology is often non existent. Throughout emphasis is placed on the variable nature of the caves resulting from differences in lithology, e.g. complex hyperphreatic mazes in Proterozoic dolomite, shallow phreatic tubes in late Precambrian limestone, phreatic caves in soft Miocene lime-stone, and unusual vadose caves in quartzite and diabase.
KARST FEATURES IN QUARTZITE OF SOUTH AFRICA - The author describes karst features developed in quartzite and also, but to a lesser extent, in weathered diabase and in wad. In quartzite, the karst is due to weathering along joints and bedding planes, producing softer areanaceous boundaries. Later, vadose caves form by piping in the weathered material, starting at a spring and progressing upstream. The karst features include dolines, swallow-holes, and caves, grouped in very localised systems. Over most of the quartzite plateaus, however, real karst features are absent and the drainage remains superficial. The only ubiquitous features, reminiscent of lapies, consist of pinnacles left after erosion of sand. As most of the time they are not associated to deep karst systems, the author proposes that they should not be considered as karst features. Other caves are developed in weathered diabase and dolomite (wad), sandwiched between resistant quartzite layers. They result from the erosion of these soft layers. The author is of the opinion that the term karst rather than pseudokarst should be used to describe this morphology developed in silica and silicate rocks. The reason is that not only the features produced compare well with the ones observed in " soluble rocks " (limestone, gypsum, etc.), but that the genetical process is very similar. It is suggested that the term pseudokarst should be used only in cases were the genesis is different.
Data on the age structure, fecundity, egg morphology and feeding habits of the Spelaeiacris tabulae population from Wynberg cave are reported and compared with other Rhaphidophoridae species. S. tabulae shows a certain degree of adaptation to cave life, as usual in the other temperate species of Rhaphidophoridae.
This paper argues that southern Africa was a remote part of the Old World in the late Pleistocene (125-10 ka ago). Because of this isolated position there was continuity without significant replacement in the resident population. Isolation and the relatively recent spread of agriculture to the region has allowed a section of this population to survive into the present. They are the Bushmen (San). Studies of geographic patterning in conventional genetic markers and mitochrondrial DNA indicate that the Bushman clade has a long evolutionary history in southern Africa. Estimates of more than 100 ka for the continued presence of this population in the region are supported in archaeological investigations of sites with long sequences such as Klasies River main site and Border Cave. Human remains dating to the earlier part of the late Pleistocene have been recovered from these sites and the samples form a morphological series with the Klasies River remains possibly 20 ka older than those from Border Cave. There is no fossil record for the later Pleistocene, however, at a period when selection for a gracile morphology may have been pronounced. The cultural associations in the earlier late Pleistocene are with the Middle Stone Age. Expressions of cultural 'style' and the occurrence of similar artefact design types in the Middle and Later Stone Ages can be interpreted with reference to the ethnographic present. Temporal continuity can be shown in the geographical distribution of stylistic markers and this suggests participation in a shared cognitive system. The inference is that the people in the earlier late Pleistocene had cognitive abilities that are comparable to those shown by their Holocene and modern descendants. The presence of the ancestors of a modern population in the earlier late Pleistocene in this region is perhaps expected if modern people had their origins in Africa