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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
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. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
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,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
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. ...

Caves - landscapes without light

akop on 05 Feb, 2012
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. ...

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Chemistry and Karst, White, William B.
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Your search for gash breccia (Keyword) returned 2 results for the whole karstbase:
The nature and origin of the ghost-rocks at Bullslaughter Bay, South Wales, 2012, Rowberry Matt D. , Battiauqueney Yvonne, Blazejowski Blazej, Walsh Peter

The ‘ghost-rocks’ of the British Isles have attracted very little research interest over the years despite being widely distributed. In South Wales, the ghost-rocks of the Pembroke Peninsula are usually associated with the mudrock formations immediately above and below the Carboniferous Limestone. This study focuses on their nature and origin through a detailed investigation of the cliff sections at Bullslaughter Bay. The investigated ghost-rocks are associated with a suite of breccias, collectively termed the Gash Breccias. These are an enigmatic suite of around twenty-five large breccia masses located exclusively in the eastern part of the peninsula. They comprise huge masses of coarse, chaotic, clast-supported, monomictic breccia and represent highly disturbed features in the otherwise unbroken sequences of Carboniferous Limestone. Their origin may be karstic, tectonic, or a combination of the two. They could, theoretically, have formed at any point between the end of the Carboniferous and the Pliocene. If their origin is karstic, it cannot yet be determined if the processes were attributable to per descensum or per ascensum groundwater systems. If tectonic, it is not known whether they formed during periods of compression or extension. From our own geological and geophysical fieldwork, we believe that the breccias originated as a result of subterranean karstic processes whilst retaining an open mind with regard to the role played by tectonics. The breccia and ghost-rocks are both displayed in fine cliff exposures around Bullslaughter Bay. These sections, although not extensive, are extremely instructive. The processes that generate ghost-rock result in isovolumetric weathering of the host rock and an associated loss of density and strength. They may or may not involve the removal of certain chemical constituents in the regolith through solution and hydrolysis followed by the formation of secondary minerals, frequently clay. In reality, the precise weathering process differs according to the type of rock. The process is controlled by the permeability of each rock type in banded rocks such as mudstones or shale with banded chert whereas it is controlled by fissures and faults in homogenous rocks. This control is clearly seen in the Carboniferous Limestone around Bullslaughter Bay, where ghost-rocks are present, more commonly in case of impure or dolomitic limestone. At present, it is not clear whether the groundwater movements were caused by hydrothermal or meteoric processes and this forms the basis of ongoing research. Finally, the study considers the relationship that exists between the ghost-rock and the Gash Breccia. We examine whether there is a logical correlation between the processes that came to generate the ghost-rock and the processes responsible for the generation of the breccia. It may then be possible to accurately state whether the ghost-rock formed before, during, or after, the breccia. The reasons that the ghost-rocks of the British Isles have attracted very little research interest may stem from the fact that they have no current commercial value, have seldom presented engineering problems, and are normally difficult to date. It is clear that numerous karst related sag-subsidences in the British Isles result from the large-scale decalcification of the Carboniferous Limestone (e.g. the Tortonian Brassington Formation of the southern Pennines). There is, however, an increasingly large body of evidence to suggest that these subsidences result from the same processes that generate ghost-rock rather than those that create endokarstic voids. The subsidences may preserve stratigraphical sequences several decametres thick and reach depths and widths of many hectometres. Unfortunately, the masses of decalcified limestone below the Tortonian sediments are of no commercial interest and have hardly ever been penetrated by boreholes. Therefore, we do not know exactly what underlies the karstic fills. The possibility that most of these structures are best explained as the result of per ascensum groundwater flow is discussed.


The weathered Carboniferous limestone at Bullslaughter Bay, South Wales: the first example of ghost-rock recorded in the British Isles, 2014, Rowberry Matt D. , Battiauqueney Yvonne, Walsh Peter, Blazejowski Blazej, Boutroumazeilles Viviane, Trentesaux Alain, Krizova Lenka, Griffiths Hywel

The Carboniferous Limestone at Bullslaughter Bay hosts some of the most notable examples of deep weathering in  the British Isles as well as two members of an enigmatic suite of breccias known as the Gash Breccias. The weathered limestone has  been investigated thoroughly in order to identify the process responsible for the weathering. In this paper it is demonstrated that the  weathering is isovolumetric but the weathering profile is not characterised by a vertical gradient and its depth suggests that meteoric  waters did not contribute significantly to the weathering process. The weathered limestone has lost significant amounts of calcium and  parts are virtually decalcified. It is seen that the dominant primary minerals of illite and quartz have been preserved while secondary  clay minerals are generally absent. The weathered limestone cannot be a saprolite sensu stricto as it has been subjected to only restricted  chemical processes. It is, therefore, interpreted as a “ghost-rock”. This type of weathering results from chemical dissolution by slow  moving waters in the saturated zone. It is suggested that the weathering may have taken place during periods of emergence in the  Carboniferous, at the same time as the cyclothem tops were exposed to subaerial modification, as evidenced by omission surfaces and  palaeokarstic solution features. This is the first time that ghost-rock weathering has been reported from the British Isles.


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