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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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That strath terrace is an erosional remnant of an elevated broad river valley [16].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for alterite (Keyword) returned 15 results for the whole karstbase:
Showing 1 to 15 of 15
GHOST-ROCK KARSTIFICATION IN ENTRE-DEUX-MERS (GIRONDE, FRANCE), IMPLICATIONS FOR KARSTOGENESIS AND KARSTIC MORPHOLOGY, , Dubois Caroline, Lans Benjamin, Kaufmann Olivier, Maire Richard, Quinif Yves

The formation of the Oligocene « calcaires à Astéries » in the region of « Entre-deux-Mers » is affected by a karstification with subhorizontal caves that drained rivers from swallow-holes to resurgences. Observations in quarries show that ghost-rock alterites are present. This paper describes the ghost-rocks in the quarry of Piquepoche exploiting the Frontenac stone. We have studied horizontally developed ghost-rocks with vertical extensions still containing the residual alterite. They can be badly consolidated calcarenites up to soft material which has been sampled. Speleogenesis is reviewed in the frame of the mechanical erosion of the alterite of a horizontal ghost-rock followed by an incision by free-flowing waters which form a passage with promontories and potholes. Finally, we show that ceiling anastomoses can form by ghost-rock karstification.


La plate-forme du Yucatn (Mexique), 1995, Heraudpia, M. A.
The Platform of the Yucatan peninsula, south of Mexico, is constituted by a tertiary carbonated series (Eocene to Pliocene). The karst landforms are a "Kuppenkarst" whose positive reliefs are more conspicuous in the centre because of greater altitude (0 to 400 m). Most caves are developed under the base level. The cenote corres-ponds to drowned pits which can be 100 m deep or more. The flooded caves, like Nohoch Nah Chich (40km long), are the longest in the world. The history of karstification began during the Tertiary, between the end of Eocene to Pliocene in relation with uplift. The crypto-dissolution occurs under an alte-ritic cover which comes from a former silicated detritic cover (south peninsula crystalline massif). Speleogenesis depends on the halocline i.e. mixing corrosion zone (salt water/fresh water) and the fluctuations of the sea level.

The carbonated palaeosurface of the ''Arbailles'' massif (Pyrennes-Atlantiques): An example of Neogene hydrographic network dried up by uplift and karstification, 1997, Vanara N. , Maire R. , Lacroix J. ,
The ''Arbailles'' massif constitutes a folded area of Jurassic and lower Cretaceous limestones, which belongs to the north-Pyrenean zone. The top karst surface was dug by a palaeofluviatile system from the Albian marlous limestone cover and dried up by uplift (infiltration). This hydrographic network recorded the main events of uplift by staged valley levels (950, 850, 730 and 380 m). Some old endokarstic infillings can be seen on the residual cone karst showing the erosion of a thick limestone layer. The alterite pockets contain elements of former cuirasses which originated in former hydromorphic depressions. These polygenic deposits contain two kinds of mineral families coming from alterations of both Albian marlous limestones and Triassic Mendibelza conglomerates. During the Upper Oligocene and Miocene (after the Middle Lutetian orogenesis), the ''Arbailles'' massif was a chemical weathering surface in a wet and tropical climate in relation upstream with Mendibelza conglomerates and downstream with Cenomanian flyschs. The Plio-Quaternary uplift, of 1000 m, caused the alterite and cuirasse erosion, the drying up of the fluviatile system (Lower Pleistocene), the genesis of a cone karst and the formation of underground systems

Le karst des Arbailles (Pyrnes-Atlantiques, France), 2000, Vanara, Nathalie
The Arbailles massif (200 - 1200 m) is located in the french north face of Pyrnes, Atlantic side. It forms a folded 165 square-kilometres unit of jurassic and cretaceous limestones under an oceanic climate of altitude (2000 mm/year). Observations jointly made on the surface and in the numerous underground galleries allow an occurate correlation of alternate surrective and karstic periods. The dismantled cavities and deposits pockets of the upper surface show two series of minerals, those from weathered marly-albian limestones and others supplied from the conglomerates pudding-stones of Mendibelza. During the Miocene, the Arbailles massif is a low area of tropical erosion on the side of the main mounts. Its surrection caused the scouring of the alterites cover, the formation of fields of karstic butts and a definitive drying of the fluviatile paleosystem. The different levels of dried valleys and the karstic hydrographic systems are successive stations of the karstic levels of origine. Paleomagnetic datations in Etxanko Zola and U/Th datations in Nbl show that the surrection has been of about 500 m since lower Pleistocene. At the present time, water collection is made through drainage systems without any connection to the fossil topography. Three aquifers can be distinguished: in lower cretaceous, in jurassic and in north and south limits. They are water-repellent because of more or less impermeable screens. Waters are aggressive in summer and at equilibrium or lightly undersaturated the rest of the year. The modern human activities create a recent destabilisation of the environment with local erosions of grounds and an increasing turbidity of springs. An occurate study in the fail of Istaurdy allows a mesure of the effect of deforestation for the whole massif.

Reconstitution morpho_lo_gique du Causse du Larzac (Aveyron, France), rle des formations superficielles dans la morphogense karstique, 2001, Bruxelles, Laurent
The study of post-Jurassic deposits, superficial formations which stay on the plateau or are preserved in caves permits us, together with the morphologies of landscape, to reconstitute the main steps of morphological evolution of this part of the Larzac. In particular, the discovery of numerous witnesses of cretaceous cover, marine and continental, let us know the first morphogenesis of the Grands Causses. After the bauxite episode, coniacian transgression fossilized a differentiated palaeotopography under one hundred meters of sandy limestone. After, the erosion of this deposits and the transit of various alterites, allogene or autochthonous, show further morphological steps. Theses formations can constitute a real cover and contribute to the development of karstic levellings. Residual formations, associated with levels of shelves, regulate lowering of karstic surface between Eocene and Miocene, before the canyon digging and the development of karstic recules. Then, between Miocene and Quaternary, karst declogging changes radically the evolution of the plateau surface and let appear poljes, dolines and underground network. Only some specific areas can keep their cover of alterites and maintain, temporally, an old functioning.

The genesis of the Tennengebirge karst and caves (Salzburg, Austria), 2002, Audra, Ph. , Quinif, Y. , Rochette, P.
Research has been carried out in the Tennengebirge Massif (Salzburg, Austria) with specific attention to karst morphology, cave systems, and sediments. This study reveals the genesis of the karst and the underground systems of the Tennengebirge, since the Oligocene. Large horizontal systems, which date back to the Miocene, were studied through the example of the caves Hornhhle and Eisriesenwelt, which respectively represent Ruinenhhlen (cave ruins) and Riesenhhlen (giant caves). The Cosa-Nostra - Bergerhhle System is typical of a mostly vertical, large, high-relief, alpine cave. The main characteristic of this network is major development in the vadose zone. Shaft morphology is in stairs beneath a faulted roof. At greater depth, they connect to a perched epiphreatic zone, which is typical of a dammed karst. The main underground sediments are of paleoclimatic and hydrodynamic significance, corresponding to hot, stable, or unstable environments (flowstones, reworked weathered rocks) and cold environments (carbonate varves, glacial pebbles). A preliminary study of the Tennengebirge sediments reveals significant information about its evolution throughout Pliocene-Quaternary time. Hhlen- und Karstgenese im Tennengebirge (Salzburg, sterreich) Es handelt sich um Erforschungen des unterirdischen Hhlensystems im Tennengebirge mit Hilfe der Erforschung der Karstsedimente. Durch die Beobachtung der Morphologie und der Ausfllungen kann die Geschichte der verschiedenen Hhlenorganisationen nachgezeichnet werden. Wir haben die groen horizontalen Hhlensysteme des Miozns anhand der Hornhhle und der Eisriesenwelt studiert, die wiederum ein Beispiel fr Ruinen- und Riesenhhlen sind. Das Cosa-Nostra - Bergerhhle System ist ein Beispiel fr die groen vertikalen Alpenschchten, das an seiner ausgeprgten Entwicklung der vadosen Zone erkenntlichist. Die Schchte haben die Morphologie von Treppen unter einem Kluftdach. Sie sind tief unten mit einer gestuften phreatischen Zone verbunden, die einen abgedmmter Karst enthllen. Die wichtigsten unterirdischen Sedimente haben eine Bedeutung auf dem Gebiet der Paloklimatologie und der hydrodynamik. Sie entsprechen entweder warmen und bestndigen oder kalten Umgebungen oder einer Umbegung in der das natrliche Gleichgewicht unterbrochen wurde (Sinterformation, vernderte Sedimente aus Alteriten, Karbonatwarven, glazial Schotter). Die Erforschung der Sedimenten in der Bergerhhle bringt wichtige Informationen ber die Entwicklung der Hhlensysteme im Plio-Quartr. Durch die gesamte Erforschung kann die Entstehung der Hhlen- und Karstgenese im Tennengebirge seit dem Oligozn nachgezeichnet werden.

Mthodes et lments de cartographie dun palokarst. Lexemple de la Carrire du Clypot (Hainaut, Belgique), 2002, Quinif Yves, Quinif Gilles
Palaeokarsts have been often considered like geological objects different from the present karst systems, which can be explored partially by speleological ways. But it is obvious that their genesis have not been different from the genesis of the neogene karst systems, in same environmental conditions. The study of palaeokarsts has a great importance for the comparison with present systems. Moreover, they conserve continental sediments which generally disappear, but with possibility of dating by marine trangressive series which cover the palaeokarsts or by absolute dating like K-Ar or Ar-Ar on glauconite or ferriferous illite. We present here an interesting example of palaeokarstic features in a quarry where the works permit to map those features. This map constitutes the basis for future studies; it has shown different types of morphological features and deposits, their geometrical relations and their genetic links. We have (i) ghosts-rocks and pseudo-endokarsts, which result from the alteration in situ of the host-rock with formation of residual alterite. Those features organise like linear channels along tectonic fractures. Some channels can joint together in great pockets. At the summit of the limestone formation, (ii) palaeo-clints develop under the transgressive cover where we find pebbles and sands. Finally, (iii) endokarstic galleries can come from an autonomous hollowing (classical karst) or from old ghost-rocks, which become partially empty by a new hydrological activity.

Morphologie et remplissage des dolines du Causse de Martel daprs les observations ralises au cours du diagnostic archologique de larodrome de Brive-Souillac (Corrze et Lot), 2006, Bruxelles Laurent, Colonge David, Salgues Thierry
Doline morphology and filling in the Causse of Martel based on the observations realized during the archaeological diagnosis of the Brive-Souillac airfield (Corrze and Lot, France) - An operation of archaeological diagnosis was led by the INRAP (national institute for preventive archaeological researches) on the Causse de Martel. On this occasion, 610 trenches with bulldozers were done, mainly localized in the bottom of dolines. The morphology of the depressions presents most often a pronounced asymmetry. We observe a gently dipping slope underlain by sandy alterites. On the opposite side, a steep corrosion rim developed in bathonian limestones. The sections show an accumulation of several meters of different sediments. At the base, we find periglacial deposits (stratified scree and yellow silt) which fossilized some archaeological remains of the middle Paleolithic. Just above an erosional unconformity, brown clays with calcareous gravel are found. Thanks to the presence of archaeological material, we date the emplacement of this level to be between the Protohistory and the medieval age. Finally, one or two meters of modern agricultural colluviums end the sequence. These observations put in evidence at least two main periods of infilling of these dolines. They correspond to two major phases of hillside imbalance. The first one has a climatic origin (Periglacial) and the second a human origin (clearings and agriculture). These accumulations are separated from the underlying deposits by distinct erosion surfaces, which can be linked to a reactivation of the karstic undercapture and the erosion of a part of the filling. This functioning corresponds to periods during which the colluviums are less abundant, indicating a certain stability of hillsides. Finally, the morphology of the rock layers and the geometry of the deposits show that the karstic landscape, which was clearly more accentuated before the Periglacial and even before Protohistory, underwent an important filling. Today, the dolines are partially filled and show with a flat bottom.

Formes et formations superficielles de la partie ouest du Causse de Sauveterre (Grands Causses, Aveyron et Lozre), 2007, Bruxelles Laurent , Simoncoinon Rgine, Guendon Jeanlouis, Ambert Paul
MORPHOLOGY AND SUPERFICIAL FORMATIONS OF THE WESTERN PART OF THE CAUSSE DE SAUVETERRE (GRANDS CAUSSES, AVEYRON AND LOZ?RE, FRANCE). In 2002, the Natural Regional Park of Grands Causses has coordinated a hydrogeological study of the western part of the Causse de Sauveterre, the northernmost of the Grands Causses. A multidisciplinary approach (geology, geomorphology, geochemistry and hydrology) was used to delineate the catchment area of the main springs and to estimate the vulnerability of karstic aquifers. The Grands Causses are situated in the southern part of the French Massif Central. The landscape is characterised by huge limestone plateaus cut by deep canyons. The morphologic study of the western part of the Causse de Sauveterre (Causse de Massegros and Causse de S?v?rac), combined with analysis of superficial formations, allows us to identify the main steps of landscape evolution. The discovery of bauxite and of many outcrops of Upper Cretaceous sandstone confirm that the Coniacian ingression invaded some paleo-landscapes developed within a long period of continental evolution which was initiated at the end of the Jurassic. During the Tertiary, many residual formations form covers of the limestone plateaus. We can distinguish alterites developed from different formations of the stratigraphic series (clay with cherts from Bajocian, dolomitic sand from Bathonian and Callovian, sandy clays from Cretaceous deposits) from some allochtonous deposits which can be found in some parts of the Causse de Massegros. These formations are found in association with morphological features (shelves, polj?s, fluvio-karstic valleys, sinkholes) and are more or less responsible of their development. Furthermore, some volcanic rocks cut through or even reused some of them. With the deepening of canyons and the base level drop, horizontal morphologies are preserved only where superficial formations are abundant and thick enough to maintain crypto-corrosion. Elsewhere, karst unplugging removes most of the superficial formations, and the karstic evolution tends to show a vertical development of morphologies and caves. Some springs, which benefit from a favourable lithologic, structural and hydrologic context, are more competitive and expand their catchment area at the expense of the other springs. Many superficial features express this dynamism on the plateau and allow us to determine the most sensible areas for water pollution and the most fragile ones for human activities.

Ptrographie dune altrite rsiduelle de type fantme de roche , 2007, Havron Ccile, Baele Jeanmarc, Quinif Yves
PETROGRAPHY OF A RESIDUAL ALTERITE GHOST-ROCK . Classically, the karstogenesis begins with a phase of dissolution along fissures. Progressively, the fissure broadens and more water flows. Some fissures transform in more important void, sometimes galleries. The fondamental fact is that the removal of bed-rock is total, the greatest part by solution (carbonates, calcium and magnesium, sodium and potassium...), the rest one like solid phase (clay minerals, quartz...). We call this process total removal. But another karstification process exists: the ghost-rock formation. The first phase of the ghost-rock formation begins with an isovolumic alteration of the bed-rock. The insoluble parts remain while the soluble parts are evacuated with underground water. This insoluble part is constituted by clays minerals, silica phase, sparite like fossils, or big cristals and forms a residual alterite. That is the ghost-rock formation. This is the case for the present example which is a residual alterite in a very pure wackestone. This object presents like a volume of alterite confined in the intact bed-rock. We study this ghost-rock by a petrographic analysis. The macroscopic approach emphasizes the great porosity of the ghost-rock which is very crumbly. The border between the ghost-rock and the bed-rock is very irregular, emphazising the petrophysic differences. The microscopic approach shows in the ghost-rock a general collapse of the structure where subsist only the best cristallized grains. The alteration increases to the detriment of the little cristals, saving the bioclasts, or to the detriment of the fissures. One detects also another phase which is constituted by gypsum. The examination using the electron microscope shows that the bed-rock is formed by well soldered grains, crystals, primary pyrite. On the other hand, the ghost-rock is characterised by a great porosity, secondary pyrite, corrosion gulfs on crystals. This is the indication that the acid function comes from sulfuric acid by oxydation of the sulfide. This is the reason of the presence of gypsum. After the alteration, the organic matter present in the bed-rock (black limestone) can reduce the gypsum in secondary sulfide. The conclusion is that the formation of the ghost-rock can develop in a pure limestone, and non only in a limestone with silico-clay skeleton. This ghost-rock represents the first stage of the genesis: an isovolumic alteration, without macroscopic void, before a collapse of the weathering rock.

GHOST-ROCK STRUCTURES AND THE NATURE OF AZ CAVES, 2011, Quinif, Yves

Because of the presence of wall and roof cupolas and other microforms indicative of differential weathering, we first of all considered the genesis of the Azé caves, following the usual concept of karstogenesis, as a phreatic formation. A second stage is a vadose evolution associated with the underground river. But the time relationship between the two caves presents a problem because
the deposits in the Aiglons gallery demonstrate a river evolution during the last glaciation. Today, we know that many karstic systems begin their genesis by a process of ghost-rock formation. The discovery of the “Galerie de Chauffailles” proves this origin, because the speleologists have removed not river sediments, but the residual alterite in a “pseudoendokarst”. Some stratigraphic sequences of
the bedrock in the prehistoric gallery can be seen as residual alterite: the “ghost-rock” in the “Galerie de Chauffailles”. The genesis of the Azé caves began by a ghost-rock phase giving a pseudoendokarstic system consisting of weathered interconnected cavities. This residual alterite is made up of less minus soluble minerals like silica cherts, clay minerals and sparitic calcite. It is very fragile and porous. The second stage consists in the mechanical removal of the residual alterite by an underground river. A very interesting characteristic of the Azé cave is that we can study the contact between the river sediments of the second stage and the residual alterit  of the first stage.

A cause de la présence de formes pariétales de type coupoles et microformes de corrosion différentielle, on a longtemps considéré la genèse de grottes telles celles d’Azé comme issue de conditions phréatiques, dans le contexte de la karstogenèse par évacuation totale. Une deuxième étape comprend une évolution vadose de type fluviatile. Mais les relations temporelles entre les deux grottes d’Azé posent un problème. Les dépôts fluviatiles de la Galerie des Aiglons démontrent qu’il a existé une circulation fluviatile durant la dernière glaciation. Cette constatation permet d’envisager une genèse de type fantôme de roche, pour laquelle cette question d’évolution ne constitue plus un problème. La découverte de la Galerie de Chauffailles prouve ce type de spéléogenèse. En effet, la désobstruction de cette galerie ne s’est pas faite dans les sédiments fluviatiles, mais pour une bonne part en retirant l’altérite résiduelle demeurée dans un pseudoendokarst. La genèse de la Grotte d’Azé commence ainsi par une altération in situ générant un système de pseudoendokarsts consistant en volumes altérés interconnectés. L’altérite résiduelle est composée des minéraux insolubles ou moins solubles comme les chailles, la calcite sparitique, les minéraux argileux. Ce milieu est fragile et très poreux. La
seconde étape évolutive est l’érosion mécanique partielle de cette altérite résiduelle par les rivières souterraines. Une caractéristique très intéressante de la grotte d’Azé est qu’il y est possible d’étudier le contact entre l’altérite résiduelle et les sédiments fluviatiles.


Laltration de type "fantme de roche" : processus, volution et implications pour la karstification, 2011, Quinif Yves, Bruxelles Laurent

Depuis plusieurs années, de nombreux exemples de fantômes de roche ont été reconnus dans les karsts en Belgique, en France et en Italie. Ils correspondent à des poches ou à des couloirs de décalcification emplis d’altérite in situ. Leur genèse relève d’un cas spécial de karstification où, à l’inverse des phénomènes de karstification par enlèvement total, le résidu insoluble ou moins soluble reste en place et forme un squelette qui mime la structure initiale de la roche (fossiles, joints, lits de chailles, etc.). Cette altérite, qui peut également se développer sous une voûte calcaire, forme un vaste réseau interconnecté et calé sur la fracturation. De fait, elle constitue une discontinuité importante au sein des massifs karstiques. Lorsque le niveau de base s’abaisse, l’altérite s’effondre sur elle-même puis elle est érodée par des circulations souterraines qui se mettent en place à son toit. Des réseaux de galeries mais aussi des formes de surface se forment alors rapidement, essentiellement par évidement de l’altérite. Ce phénomène est maintenant reconnu dans le monde entier, affectant tous les types de roches, carbonatées ou non.

For several years, numerous examples of ghost rocks have been recognised in karst areas in Belgium, in France and in Italy. They correspond to decalcified pockets but also to decalcified corridors filled with in-situ alterite. It is a special case of karstification where a non-soluble skeleton remains and preserves the structures of the initial rock (fossils, joints, levels of cherts, etc.). This alterite, which can also be formed under a safe roof, draws a large maze following the tectonic patterns. It constitutes an important discontinuity inside the karstic areas. When the base level drops, the structure of the alterite collapses and a void is formed on his top. Then runoff can use this void and erode the soft alterite. Cave network but also surface features can develop quickly, mainly by the cleaning of the alterite. Now, some examples of this phenomenon have been recognised all around the world and occur in different sorts of rocks, carbonated or not.


The primokarst, former stages of karstification, or how solution caves can born, 2014, Rodet, J.

The historical approach of the karst always gave preferential treatment to the study of the superficial phenomena or underground cavities explored by human. However as demonstrated by hydrogeologists, the main karst development keep out of reach because of the too small sizing of drains or due to its filling. Consequently appears the question about the inception drain, the way used by the water from the sink hole to reach its resurgence. Some authors consider this primary link as obvious when the practice demonstrates clearly that the hydrodynamic continuity results of a very long, complex and selective evolution, essentially geochemical. This is the field of the drain inception stages, that we can spell “prekarst” or “primokarst”. Those stages include the successive fields of isalterite and alloterite. This last one opens by compaction a free space and allows a concentrated hydrodynamic flow. These processes, at the origin of the endokarst initiation, can develop on the side of synchronous mechanical dynamics if in the same drain or under a regolith coverage, something divides the bedrock and the quick flow. Without any doubt, this is the purview of the cryptokarst and of the cave walls under filling. We can observe it in the progradation front of the introduction karst or in the retrogradation front of the restitution karst.


The process of ghost-rock karstification and its role in the formation of caves, 2014, Dubois C. , Quinif Y. , Baele J. M. , Barriquand L. , Bini A. , Bruxelles L. , Dandurand G. , Havron C. , Kaufmann O. , Lans B. , Maire R. , Martin J. , Rodet J. , Rowberry M. D. , Tognini P. , Vergari A. ,

This paper presents an extensive review of the process of ghost-rock karstification and highlights its role in the formation of cave systems. The process integrates chemical weathering and mechanical erosion and extends a number of existing theories pertaining to continental landscape development. It is a two stage process that differs in many respects from the traditional single-stage process of karstification by total removal. The first stage is characterised by chemical dissolution and removal of the soluble species. It requires low hydrodynamic energy and creates a ghost-rock feature filled with residual alterite. The second stage is characterised by mechanical erosion of the undissolved particles. It requires high hydrodynamic energy and it is only then that open galleries are created. The transition from the first stage to the second is driven by the amount of energy within the thermodynamic system. The process is illustrated by detailed field observations and the results of the laboratory analyses of samples taken from the karstotype area around Soignies in southern Belgium. Thereafter, a series of case studies provide a synthesis of field observations and laboratory analyses from across western Europe. These studies come from geologically distinct parts of Belgium, France, Italy, and United Kingdom. The process of ghost-rock karstification challenges a number of axioms associated the process of karstification by total removal. On the basis of the evidence presented it is argued that it is no longer acceptable to use karst morphologies as a basis with which to infer specific karstogenetic processes and it is no longer necessary for a karst system to relate to base level as ghost-rock karstification proceeds along transmissive pathways in the rock. There is also some evidence to suggest that ghost-rock karstification may be superseded by karstification by total removal, and vice versa, according to the amount of energy within the thermodynamic system. The proposed chemical weathering and subsequent mechanical erosion of limestone suggests that the development of karst terrain is related far more closely to the geomorphological development of aluminosilicate and siliceous terrains than is generally supposed. It is now necessary to reconsider the origin of many karst systems in light of the outlined process of ghost-rock karstification.


A new method to quantify carbonate rock weathering, 2015, Dubois Caroline, Deceuster John, Kaufmann Olivier, Rowberry Matt D.

The structure and composition of carbonate rocks is modified greatly when they are subjected to phenomena that lead to their weathering. These processes result in the production of residual alterite whose petrophysical, mechanical, and hydrological properties differ completely to those of the unweathered rock. From a geotechnical perspective, it is important that such changes are fully understood as they affect reservoir behavior and rock mass stability. This paper presents a quantitative method of calculating a weathering index for carbonate rock samples based on a range of petrophysical models. In total, four models are proposed, each of which incorporates one or more of the processes involved in carbonate rock weathering (calcite dissolution, gravitational compaction, and the incorporation of inputs). The selected weathering processes are defined for each model along with theoretical laws that describe the development of the rock properties. Based on these laws, common properties such as rock density, porosity, and calcite carbonate content are estimated from the specific carbonate rock weathering index of the model. The propagation of measurement uncertainties through the calculations has been computed for each model in order to estimate their effects on the calculated weathering index. A new methodology is then proposed to determine the weathering index for carbonate rock samples taken from across a weathered feature and to constrain the most probable weathering scenario. This protocol is applied to a field dataset to illustrate how these petrophysical models can be used to quantify the weathering and to better understand the underlying weathering processes.


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