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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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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. ...

Did you know?

That allogenic valley is a karst valley incised by a watercourse originating on impervious rock with a volume sufficient for it to traverse a limestone area on the surface. the valley is incised from the limestone contact and with the passage of time the river is increasingly likely to pass underground as the waters enlarge joints. occasionally such a valley may represent the large-scale collapse of the cavern system along a subterranean stream or the enlarging of a series of karst windows [19].?

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Chemistry and Karst, White, William B.
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Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
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Your search for feedback (Keyword) returned 36 results for the whole karstbase:
Showing 1 to 15 of 36
Principles of early development of karst conduits under natural and man-made conditions revealed by mathematical analysis of numerical models, 1996, Dreybrodt W,
Numerical models of the enlargement of primary fissures in limestone by calcite aggressive water show a complex behavior. If the lengths of the fractures are large and hydraulic heads are low, as is the case in nature, dissolution rates at the exit of the channel determine its development by causing a slow increase of water flow, which after a long gestation time by positive feedback accelerates dramatically within a short time span. Mathematical analysis of simplified approximations yields an analytical expression for the breakthrough time, when this happens, in excellent agreement with the results of a numerical model. This expression quantifies the geometrical, hydraulic, and chemical parameters determining such karat processes. If the lengths of the enlarging channels are small, but hydraulic heads are high, as is the case for artificial hydraulic structures such as darns, it is the widening at the entrance of the flow path which determines the enlargement of the conduit. Within the lifetime of the dam this can cause serious water losses, This can also be explained by mathematical analysis of simplified approximations which yield an analytical threshold condition from which the safety of a dam can be judged. Thus in both cases the dynamic processes of karstification are revealed to gain a deeper understanding of the early development of karst systems. As a further important result, one finds that minimum conditions, below which karstification cannot develop, do not exist

Evolution and dynamics of soil-geomorphic systems in karst landscapes of the European north, 1997, Goryachkin S. V. , Shavrina E. V. ,
Six types of soil-geomorphic systems within sulfate-karst landscapes in the north of European Russia have been investigated. The distinctions in structure and composition of these systems are conditioned by the tectonic fault pattern and jointing of the karstland. The soil data obtained allow us to gain an insight into the essence of geomorphic processes and to evaluate the dynamics of land surface in karst landscapes. Conceptual models of the origin and dynamics of soil-geomorphic systems of karst landscapes and the model of their evolution within the zone of dense jointing of gypsum rocks under the impact of denudation processes are suggested. The assessment of geomorphic functions of the soils in karst area attests to their importance as the controls of potential erosion. Only soil-biotic processes (Litter accumulation) are undoubtedly protective, while other processes may either hinder or strongly intensify the erosion. After the Quaternary sediments are removed and the erosion starts to penetrate into the hard gypsum layer, a strong positive feedback between soil-forming and karst-forming processes appears. Thus, the final stages of the evolution of soil-geomorphic systems in karst landscapes are characterized by great dynamism

Development, management and economy of show caves, 2000, Burri Ezio, Cigna Arrigo A.
The problems concerning the development of show caves are here considered by taking into account different aspects of the problem. A procedure to carry out an Environmental Impact Assessment (EIA) has been established in the last decade and it is now currently applied. Such an assessment starts with a pre-operational phase to obtain sufficient information on the undisturbed status of a cave to be developed into a show cave. Successively a programme for its development is established with the scope to optimise the intervention on the cave at the condition that its basic environmental parameters are not irreversibly modified. The last phase of the assessment is focussed to assure a feedback through a monitoring network in order to detect any unforeseen difference or anomaly between the project and the effective situation achieved after the cave development. Some data on some of the most important show caves in the world are reported and a tentative evaluation of the economy in connection with the show caves business is eventually made.

Carbonate platform systems: components and interactions -- an introduction, 2000, Insalaco Enzo, Skelton Peter, Palmer Tim J. ,
Carbonate platforms are open systems with natural boundaries in space and time. Across their spatial boundaries there are fluxes of energy (e.g. light, chemical energy in compounds, and kinetic energy in currents and mass flows) and matter (e.g. nutrients, dissolved gases such as CO2, and sediment -- especially, of course, carbonates). Internally, these fluxes are regulated by myriads of interactions and feedbacks (Masse 1995), and the residue is consigned to the geological record. The most distinctive aspect of carbonate platforms is the predominant role of organisms in producing, processing and/or trapping carbonate sediment, even in Precambrian examples. Because of evolutionary changes in this strong biotic input, it is harder to generalize about carbonate platforms than about most other sedimentary systems. Evolution has altered both the constructive and destructive effects of platform-dwelling organisms on carbonate fabrics, with profound consequences for facies development. Moreover, changing patterns in the provision of accommodation space (e.g. between greenhouse and icehouse climatic regimes) have also left their stamp on facies geometries, in turn feeding back to the evolution of the platform biotas. Hence simplistic analogies between modern and ancient platforms may give rise to misleading interpretations of what the latter were like and how they formed. Although a number of carbonate platform and reef specialists have warned of the dangers of such misplaced uniformitarianism (e.g. Braithwaite 1973; Gili et al. 1995; Wood 1999), it remains depressingly commonplace in the literature on ancient carbonate platforms. The endless quest in the literature for an allpurpose definition of reefs' ... This 250-word extract was created in the absence of an abstract

Dynamics of the evolution of single karst conduit, 2000, Dreybrodt W. , Gabrovsek F.
The evolution of karst conduits by calcite-aggressive water flowing in initially narrow fractures require a non-linear rate law FSUBn(c)=kSUBn(1-c/cSUB eg)SUPn for limestone dissolution close to equilibrium with respect to calcite. A mathematical analysis of the evolution of limestone dissolution rates of water in such early, narrow fractures as a function of the distance from the input reveals an exponential decrease of the dissolution rates for linear dissolution rate laws (n=1), such that subsurface karstification is prevented. For non-linear kinetics (n>2), however, the decrease of rates proceeds by a hyperbolic relation, such that dissolution rates at the exit of the fracture are still sufficiently high to create a feedback mechanism by which after a long time of gestation a dramatic increase in the widths of the conduits is established. After this breakthrough event, uniform widening along the entire channel determines the further evolution. The time to achieve breakthrough is given by T=aSUB0/2gammaF(L,0), where 2gammaF(L,0) is the initial widening in cm/year at the exit of the conduit. This however is only true when the inflow solution is at less than 99% of saturation. Otherwise the positive feedback loop is switched off and the conduit widens evenly along its entire length with rates of 10SUP-9 cm/year to enlarge extremely narrow fractures with initial widths of several ten microns over distances of kilometers to sizes of about 0.1mm within several ten millions of years. This provides a general explanation for the concept of inception horizons, where usually other mechanisms have been assumed.

Modelling karst aquifer genesis using a coupled continuum-pipe flow model, 2000, Sauter M. , Liedl R.
This contribution presents a modeling approach for the simulation of karst aquifer genesis during geologic time periods. The approach used here is based upon a hydraulic coupling of a pipe network to a continuum in order to represent the well-known duality of karst aquifer flow systems. In addition, the growth of the karst conduits due to carbonate dissolution can be simulated so that a feedback mechanism with respect to the hydraulic properties of the pipe network is established. The model is applied to some typical scenarios of karst aquifer genesis, i. e. the evolution of a dendritic tube system and of a maze cave network. It is found that the model results can successfully reproduce the basic features of karst development, e. g. the development of maze caves in a carbonate aquifer which is covered by a sandstone caprock.

Speleogenesis: Evolution of Karst Aquifers., 2000,
The aim of this book is to present advances made in recent decades in our understanding of the formation of dissolutional caves, and to illustrate the role of cave genetic ( speleogenetic ) processes in the development of karst aquifers. From the perspective of hydrogeology, karst ground water flow is a distinct kind of fluid circulation system, one that is capable of self-organization and self-development due to its capacity to dissolve significant amounts of the host rock and transport them out of the system. Fluid circulation in soluble rocks becomes more efficiently organized by creating, enlarging and modifying patterns of cave conduits, the process of speleogenesis. We can assert that karst ground water flow is a function of speleogenesis and vice versa . The advances in cave science are poorly appreciated in what may be termed ?mainstream hydrogeology?, which retains a child-like faith in flow models developed in the sand box. Many karst students also will not be aware of all emerging concepts of cave origin because discussions of them are scattered through journals and books in different disciplines and languages, including publications with small circulation. An understanding of principles of speleogenesis and its most important controls is indispensable for proper comprehension of the evolution of the karst system in general and of karst aquifers in particular. We hope this book will be useful for both karst and cave scientists, and for general hydrogeologists dealing with karst terranes. This book is a pioneer attempt by an international group of cave scientists to summarize modern knowledge about cave origin in various settings, and to examine the variety of approaches that have been adopted. Selected contributions from 44 authors in 15 nations are combined in an integrated volume, prepared between 1994 and 1998 as an initiative of the Commission of Karst Hydrogeology and Speleogenesis, International Speleological Union. Despite a desire to produce an integrated book, rather than a mere collection of papers, the editors' policy has not been directed toward unifying all views. Along with some well-established theories and approaches, the book contains new concepts and ideas emerging in recent years. We hope that this approach will stimulate further development and exchange of ideas in cave studies and karst hydrogeology. Following this Introduction, (Part 1), the book is organized in seven different parts, each with sub-chapters. Part 2 gives a history of speleogenetic studies, tracing the development of the most important ideas from previous centuries (Shaw, Chapter 2.1) through the early modern period in the first half of this century (Lowe, Chapter 2.2) to the threshold of modern times (W.White, Chapter 2.3). The present state of the art is best illustrated by the entire content of this book. Part 3 overviews the principal geologic and hydrogeologic variables that either control or significantly influence the differing styles of cave development that are found. In Chapter 3.1 Klimchouk and Ford introduce an evolutionary approach to the typology of karst settings, which is a taken as a base line for the book. Extrinsic factors and intrinsic mechanisms of cave development change regularly and substantially during the general cycle of geological evolution of a soluble rock and , more specifically, within the hydrogeologic cycle. The evolutionary typology of karst presented in this chapter considers the entire life cycle of a soluble formation, from deposition (syngenetic karst) through deep burial, to exposure and denudation. It helps to differentiate between karst types which may concurrently represent different stages of karst development, and is also a means of adequately classifying speleogenetic settings. The different types of karst are marked by characteristic associations of the structural prerequisites for groundwater flow and speleogenesis, flow regime, recharge mode and recharge/discharge configurations, groundwater chemistry and degree of inheritance from earlier conditions. Consequently, these associations make a convenient basis to view both the factors that control cave genesis and the particular types of caves. Lithological and structural controls of speleogenesis are reviewed in general terms in Chapters 3.2 (Klimchouk and Ford). Lowe in Chapter 3.3 discusses the role of stratigraphic elements and the speleo-inception concept. Palmer in Chapter 3.4 overviews the hydrogeologic controls of cave patterns and demonstrates that hydrogeologic factors, the recharge mode and type of flow in particular, impose the most powerful controls on the formation of the gross geometry of cave systems. Hence, analysis of cave patterns is especially useful in the reconstruction of environments from paleokarst and in the prediction and interpretation of groundwater flow patterns and contaminant migration. Any opportunity to relate cave patterns to the nature of their host aquifers will assist in these applied studies as well. Osborne (Chapter 3.7) examines the significance of paleokarst in speleogenesis. More specific issues are treated by Klimchouk (The nature of epikarst and its role in vadose speleogenesis, Chapter 3.5) and by V.Dublyansky and Y.Dublyansky (The role of condensation processes, Chapter 3.6). Part 4 outlines the fundamental physics and chemistry of the speleogenetic processes (Chapter 4.1) and presents a variety of different approaches to modeling cave conduit development (Chapter 4.2). In Chapter 4.1, the chemical reactions during the dissolution of the common soluble minerals, calcite, gypsum, salt and quartz, are discussed with the basic physical and chemical mechanisms that determine their dissolution rates. As limestone is the most common karst rock and its dissolution is the most complex in many respects, it receives the greatest attention. Dreybrodt (Section 4.1.1) and Dreybrodt and Eisenlohr (Section 4.1.2) provide advanced discussion and report the most recent experimental data, which are used to obtain realistic dissolution rates for a variety of hydrogeologic conditions and as input for modeling the evolution of conduits. Although direct comparisons between theoretical or analytical dissolution rates and those derived from field measurements is difficult, a very useful comparison is provided by W.White (Section 4.1.3). The bulk removal of carbonate rock from karst drainage basins can be evaluated either by direct measurement of rock surface retreat or by mass balance within known drainage basins. All of these approaches make sense and give roughly accurate results that are consistent with theoretical expectations. It is well recognized today that the earliest, incipient, phases of speleogenesis are crucial in building up the pattern of conduits that evolve into explorable cave systems. It is difficult to establish the major controls on these initial stages by purely analytical or intuitive methods, so that modeling becomes particularly important. Various approaches are presented in Chapter 4.2. Ford, Ewers and Lauritzen present the results of systematic study of the propagation of conduits between input and output points in an anisotropic fissure, using a variety of hardware and software models, in series representing the "single input", "multiple inputs in one rank", and "multiple inputs in multiple ranks" cases (Section 4.2.1). The results indicate important details of the competitive development of proto-conduits and help to explain branching cave patterns. In the competition between inputs, some principal tubes in near ranks first link ("breakthrough") to an output boundary. This re-orients the flowfields of failed nearby competitors, which then extend to join the principal via their closest secondaries. The process extends outwards and to the rear, linking up all inputs in a "cascading system". The exploding growth of computer capability during the last two decades has greatly enhanced possibilities for digital modeling of early conduit development. Investigating the growth of a single conduit is a logical first step in understanding the evolution of caves, realized here by Dreybrodt and Gabrov?ek in the form of a simple mathematical model (Section 4.2.2) and by Palmer by numerical finite-difference modeling (Section 4.2.3). The models show that positive feedback loops operate; widening a fracture causes increasing flow through it, therefore dissolution rates increase along it and so on, until finally a dramatic increase of flow rates permits a dramatic enhancement of the widening. This breakthrough event terminates the initial stage of conduit evolution. From then on the water is able to pass through the entire conduit while maintaining sufficient undersaturation to preserve low-order kinetics, so the growth rate is very rapid, at least from a geological standpoint -- usually about 0.001-0.1 cm/yr. The initiation ("breakthrough") time depends critically on the length and the initial width of the fracture and, for the majority of realistic cases, it covers a time range from a few thousand years to ten million years in limestones. The modeling results give a clear explanation of the operation of selectivity in cave genesis. In a typical unconfined karst aquifer there is a great range of enlargement rates along the competing flow routes, and only a few conduits will grow to enterable size. The modeling also provides one starting point (others are discussed in Chapter 5.2) to explain uniform maze patterns, which will be favored by enlargement of all openings at comparable rates where the discharge/length ratio is great enough. Single-conduit modeling has the virtue of revealing how the cave-forming variables relate to each other in the simplest possible way. Although it is more difficult to extend this approach to two dimensions, many have done so (e.g. Groves & Howard, 1994; Howard & Groves, 1995; in this volume ? Ford, Ewers and Lauritzen, Section 4.2.1; Dreybrodt and Siemers, Section 4.2.4, and Sauter and Liedl, Section 4.2.5). The modeling performed by Dreybrodt and Siemers shows that the main principles of breakthrough derived from one-dimensional models remain valid. The evolution of karst aquifers has been modeled for a variety of different geological settings, including also variation in lithology with respect to the dissolution kinetics. Sauter and Liedl simulate the development of conduits at a catchment scale for fissured carbonate rocks with rather large initial openings (about 1 mm). The approach is based upon hydraulic coupling of a pipe network to matrix continuum in order to represent the well-known duality of karst aquifer flow systems. It is also shown how understanding of the genesis of karst aquifers and modeling of their development can assist in characterization of the conduit system, which dominates flow and transport in karst aquifers. An important point that has emerged from cave studies of the last three decades is that no single speleogenetic model applies to all geologic and hydrologic settings. Given that settings may also change systematically during the evolutionary geological cycles outlined above (Chapter 3.1), an evolutionary approach is called for. This is attempted in Part 5, which is organized to give extended accounts of speleogenesis in the three most important settings that we recognize: coastal and oceanic (Chapter 5.1), deep-seated and confined (Chapter 5.2) and unconfined (Chapter 5.3). Each Chapter begins with a review of modern ideas on cave development in the setting, followed by representative case studies. The latter include new accounts of some "classic" caves as well as descriptions of other, little-known cave systems and areas. Readers may determine for themselves how well the real field examples fit the general models presented in the introductory sections. Mylroie and Carew in Chapter 5.1 summarize specific features of cave and karst development in young rocks in coastal and island settings that result from the chemical interactions between fresh and salt waters, and the effects of fluctuating sea level during the Quaternary. The case studies include a review of syngenetic karst in coastal dune limestones, Australia (S.White, 5.1.1) and an example of speleogenesis on tectonically active carbonate islands (Gunn and Lowe, 5.1.2). Klimchouk in Chapter 5.2 reviews conditions and mechanisms of speleogenesis in deep-seated and confined settings, one of the most controversial but exciting topics in modern cave research. Conventional karst/speleogenetic theories are concerned chiefly with shallow, unconfined geologic settings, supposing that the karstification found there is intimately related to surface conditions of input and output, with the dissolution being driven by downward meteoric water recharge. The possibility of hypogenic karstification in deeper environments has been neglected for a long time, and the quite numerous instances of karst features found at significant depths have usually been interpreted as buried paleokarst. However, the last decade has seen a growing recognition of the variety and importance of hypogene dissolution processes and of speleogenesis under confined settings which often precedes unconfined development (Hill, 1987, 1995; Klimchouk, 1994, 1996, 1997; Lowe, 1992; Lowe & Gunn, 1995; Mazzullo & Harris, 1991, 1992; Palmer, 1991, 1995; Smart & Whitaker, 1991; Worthington, 1991, 1994; Worthington & Ford, 1995). Confined (artesian) settings were commonly ignored as sites for cave origin because the classic concept of artesian flow implies long lateral travel distances for groundwater within a soluble unit, resulting in a low capacity to generate caves in the confined area. However, the recognition of non-classical features in artesian flow, namely the occurrence of cross-formation hydraulic communication within artesian basins, the concepts of transverse speleogenesis and of the inversion of hydrogeologic function of beds in a sequence, allows for a revision of the theory of artesian speleogenesis and of views on the origin of many caves. It is proposed that artesian speleogenesis is immensely important to speleo-inception and also accounts for the development of some of the largest known caves in the world. Typical conditions of recharge, the flow pattern through the soluble rocks, and groundwater aggressiveness favor uniform, rather than competing, development of conduits, resulting in maze caves where the structural prerequisites exist. Cross-formational flow favors a variety of dissolution mechanisms that commonly involve mixing. Hydrogeochemical mechanisms of speleogenesis are particularly diverse and potent where carbonate and sulfate beds alternate and within or adjacent to hydrocarbon-bearing sedimentary basins. Hypogene speleogenesis occurs in rocks of varied lithology and can involve a variety of dissolution mechanisms that operate under different physical constraints but create similar cave features. Case studies include the great gypsum mazes of the Western Ukraine (Klimchouk, Section 5.2.1), great maze caves in limestones in Black Hills, South Dakota (Palmer, Section 5.2.2) and Siberia (Filippov, Section 5.2.3), karstification in the Redwall aquifer, Arizona (Huntoon, Section 5.2.4), hydrothermal caves in Hungary (Y.Dublyansky, Section 5.2.6), and sulfuric acid speleogenesis (Lowe, Bottrell and Gunn, Section 5.2.7, and Hill, Section 5.2.8). Y.Dublyansky summarizes the peculiar features of hydrothermal speleogenesis (Section 5.2.5), and V.Dublyansky describes an outstanding example of a hydrothermal cavity, in fact the largest ever recorded by volume, in the Rhodope Mountains (Section 5.2.9). Recognition of the scale and importance of deep-seated speleogenesis and of the hydraulic continuity and cross-formational communications between aquifers in artesian basins is indispensable for the correct interpretation of evolution of karst aquifers, speleogenetic processes and associated phenomena, regional karst water-resource evaluations, and the genesis of certain karst-related mineral deposits. These and other theoretical and practical implications still have to be developed and evaluated, which offers a wide field for further research efforts. Ford in Chapter 5.3 reviews theory of speleogenesis that occurs where normal meteoric waters sink underground through the epikarst or dolines and stream sinks, etc. and circulate in the limestone or other soluble rocks without any major artesian confinement. These are termed common caves (Ford & Williams, 1989) because they probably account for 90% or more of the explored and mapped dissolutional caves that are longer than a few hundred meters. This estimate reflects the bias in exploration; caves formed in unconfined settings and genetically related to surface recharge are the most readily accessible and hence form the bulk of documented caves. Common caves display chiefly the branchwork forms where the dissolutional conduits occupy only a tiny proportion of the total length or area of penetrable fissures that is available to the groundwaters. The rules that govern the selection of the successful linkages that will be enlarged into the branchwork pattern are supported in the models presented in Chapter 4.2. In the long section caves may be divided into deep phreatic, multi-loop, mixed loop and water table, and ideal water table types, with drawdown vadose caves or invasion vadose caves above them. Many large systems display a mixture of the types. The concepts of plan pattern construction, phreatic, water table or vadose state, and multi-phase development of common caves are illustrated in the case studies that follow the introduction. They are organized broadly to begin with examples of comparatively simple deep phreatic and multi-loop systems (El Abra, Mexico, Ford, Section 5.3.1 and Castleguard Cave, Canada, Ford, Lauritzen and Worthington, Section 5.3.2), proceeding to large and complex multi-phase systems such as the North of Thun System, Switzerland (Jeannin, Bitterly and Hauselmann, Section 5.3.3) and Mammoth Cave, Kentucky (Palmer, Section 5.3.8), to representatives of mixed vadose and phreatic development in mountainous regions (the Alps, Audra, Section 5.3.4; the Pyrenees, Fernandez, Calaforra and Rossi, Section 5.3.5; Mexico, Hose, Section 5.3.6) and where there is strong lithologic or structural control (Folded Appalachians, W.White, Section 5.3.7; gypsum caves in the South of Spain, Calaforra and Pulido-Bosch, Section 5.3.10). Two special topics are considered by W.White in Section 5.3.9 (Speleogenesis of vertical shafts in the eastern US) and Palmer (Maze origin by diffuse recharge through overlying formation). The set concludes with two instances of nearly ideal water table cave development (in Belize and Hungary, Ford, Section 5.3.12), and a review of the latest models of speleogenesis from the region where modern karst studies in the West began, the Classical Karst of Slovenia and Trieste (?u?ter?ic, Section 5.3.13). In Parts 2-5 attention is directed primarily on how the gross geometry of a cave system is established. Part 6 switches focus to the forms at meso- and micro- scales, which can be created during enlargement of the cave. Lauritzen and Lundberg in Chapter 6.1 summarize the great variety of erosional forms ( speleogenetic facies ) that can be created by a wide range of speleogenetic agents operating in the phreatic or vadose zones. Some forms of cave passages have been subject to intensive research and may be interpreted by means of simple physical and chemical principles, but many others are polygenetic and hence difficult to decipher with certainty. However, in addition to the analysis of cave patterns (see Chapter 3.4), each morphological element is a potential tool that can aid our inferences on the origin of caves and on major characteristics of respective past hydrogeological settings. In Chapter 6.2 E.White and W.White review breakdown morphology in caves, generalizing that the processes are most active during the enlargement and decay phases of cave development. Early in the process breakdown occurs when the flow regime shifts from pipe-full conditions to open channel conditions (i.e. when the roof first loses buoyant support) and later in the process breakdown becomes part of the overall degradation of the karst system. The chapter addresses the mechanism of breakdown formation, the geological triggers that initiate breakdown, and the role that breakdown plays in the development of caves. As the great majority of both theoretical considerations and case studies in this book deal with speleogenesis in carbonate rocks, it is useful to provide a special forum to examine dissolution cave genesis in other rocks. This is the goal of Part 7. Klimchouk (7.1) provides a review of speleogenesis in gypsum. This appears to be a useful playground for testing the validity and limitations of certain general speleogenetic concepts. Differences in solution kinetics between gypsum and calcite impose some limitations and peculiar features on the early evolution of conduits in gypsum. These peculiarities appear to be an extreme and more obvious illustration of some rules of speleogenetic development devised from conceptual and digital modeling of early conduit growth in limestones. For instance, it is shown (e.g. Palmer, 1984, 1991; Dreybrodt, 1996; see also Chapter 3.4 and Section 4.2.2) that initiation of early, narrow and long pathways does not seem feasible under linear dissolution rate laws (n=1) due to exponential decrease of the dissolution rates. Although the dissolution kinetics of gypsum are not well known close to equilibrium it is generally assumed that they are controlled entirely by diffusion and therefore linear. If dissolution of gypsum is solely diffusion-controlled, with no change in the kinetic order, conduit initiation could not occur in phreatic settings or by lateral flow through gypsum from distant recharge areas in artesian settings. Hence, the fact that maze caves are common in gypsum in artesian conditions (see Section 5.2.1) gives strong support to a general model of "transverse" artesian speleogenesis where gypsum beds are underlain by, or sandwiched between, insoluble or low-solubility aquifers (Chapter 5.2), and suggests that it may be applicable to cave development in carbonates. In unconfined settings, speleogenesis in gypsum occurs along fissures wide enough to support undersaturated flow throughout their length. Linear or crudely branching caves overwhelmingly predominate, which rapidly adjust to the contemporary geomorphic setting and to the maximum available recharge. Also, if considerable conduit porosity has been created in deep-seated settings, it provides ready paths for more intense groundwater circulation and further cave development when uplift brings the gypsum into the shallow subsurface. Speleogenesis in salt, reviewed in general and exemplified by the Monte Sedom case in Israel (Frumkin, Chapter 7.2), has been documented only in open, unconfined settings, where it provides a model for simple vadose cave development. Chapter 7.3 deals with speleogenesis in quartzites, illustrated by case studies from southeastern Minas Gerais, Brasil (Correa Neto, 7.3.1) and South Africa (Martini, 7.3.2). The process involves initial chemical weathering of the quartzite to create zones of friable rocks (sanding, or arenisation) which then are removed by piping, with further conduit enlargement due to mechanical erosion by flowing water. Part 8 combines the theoretical with some applied aspects of speleogenetic studies. Worthington, Ford and Beddows (8.1) show the important implications of what might be termed "speleogenetic wisdom" when studying ground water behaviour in karst. They examine some standard hydrogeological concepts in the light of knowledge of caves and their patterns, considering a range of case studies to identify the characteristic enhancement of porosity and permeability due to speleogenesis that occurs in carbonate rocks. The chapter focuses on unconfined carbonate aquifers as these are the most studied from the speleological perspective and most important for water supplies. Four aquifers, differing in rock type, recharge type (allogenic and autogenic), and age (Paleozoic, Mesozoic and Cenozoic), are described in detail to demonstrate the extent of dissolutional enhancement of porosity and permeability. It is shown that all four cases are similar in hydraulic function, despite the fact that some of them were previously characterized as different end members of a "karst ? non-karst" spectrum. Enhancement of porosity by dissolution is relatively minor: enhancement of permeability is considerable because dissolution has created dendritic networks of channels able to convey 94% or more of all flow in the aquifer, with fractures providing a small proportion and the matrix a negligible amount. These conclusions may be viewed as a warning to hydrogeologists working in carbonate terranes: probably the majority of unconfined aquifers function in a similar manner. Sampling is a major problem in their analysis because boreholes (the conventional exploration tool in hydrogeology) are unlikely to intersect the major channels that are conveying most of the flow and any contaminants in it. It is estimated, using examples of comprehensively mapped caves, that the probability of a borehole intersecting a conduit ranges from 1 in 50 to 1 in 1000 or more. Boreholes simply cannot be relied upon to detect the presence of caves or to ?characterise? the hydrologic functioning of cavernous aquifers. Wherever comprehensive evidence has been collected in unconfined carbonate aquifers (cave mapping plus boreholes plus lab analysis of core samples) it suggests that dissolution inexorably results in a similar structure, with channel networks providing most of the permeability of the aquifer, yet occupying a very minor fraction of its volume (Worthington, Ford and Beddows). Lowe (Chapter 8.2) focuses on developments in understanding the vital role played by karstic porosity, (broadly viewed as being the product of speleogenesis), in the migration of mineralizing fluids (or hydrocarbons) and in their deposition (or storage), and comments on the potential role of new speleogenetic concepts in developing greater understanding in the future. Although some early workers were clearly aware of actual evidence for some kind of relationship, and others noted its theoretical likelihood, it has been ignored by many until relatively recent times. This shortfall has gradually been redressed; new understanding of the extent and variety of karst processes is ensuring that new relationships are being recognized and new interpretations and models are being derived. The chapter does not pretend to give a comprehensive account of the topic but clearly demonstrates the wide applicability of speleogenetic knowledge to issues in economic geology. In Chapter 8.3 Aley provides an overview of the water and land-use problems that occur in areas with conduit aquifers. He stresses that sound land management must be premised on an understanding that karst is a three-dimensional landscape where the surface and subsurface are intimately and integrally connected. Failure to recognize that activity at the surface affects the subsurface, and the converse, has long been the root cause of many of the problems of water and land use in karst regions. Karst areas have unique natural resource problems, whose management can have major economic consequences. Although there is an extensive literature on the nature of particular problems, resource protection and hazard minimization strategies in karst, it rarely displays an advanced understanding of the processes of the conduit formation and their characteristics yet these will always be involved. This book does not pretend to be a definitive text on speleogenesis. However, it is hoped that readers will find it to be a valuable reference source, that it will stimulate new ideas and approaches to develop and resolve some of the remaining problems, and that it will promote an appreciation of the importance of speleogenetic studies in karst hydrogeology and applied environmental sciences. Acknowledgements: We sincerely thank all contributors for their willing cooperation in the long and difficult process of preparing this book, for their participation in developing its logic and methodology and their cheerful response to numerous requests. We thank all colleagues who discussed the work with us and encouraged it in many ways, even though not contributing to its content as authors. We are particularly grateful to Margaret Palmer for invaluable help in editing the English in many contributions, to Nataly Yablokova for her help in performing many technical tasks and to Elizabeth White who prepared comprehensive index. Our thanks are due to Dr. David Drew, Dr. Philip LaMoreaux, Dr. George Moore and Prof. Marian Pulina for reviewing the manuscript and producing constructive notes and comments on improvement of the final product. The organizational costs and correspondence related to the preparation of the book were partially sponsored by the National Speleological Society, the publisher. We thank David McClurg, the Chair of the NSS Special Publication Committee, for his extensive technical and organizational support in the preparation and publishing processes.

Toward a better understanding of fissure growth in karst formations: Investigations from genesis to maturation and the influence of fracture-matrix interactions., 2002, Cheung, Wendy Wai Wan

There has been interest in quantitative modeling of early karstification with the objectives of estimating time-scales of conduit growth and understanding the nature of cave patterns. In particular, the initiation phase has been studied in great detail because it is the slowest phase in the development of caverns. In this study aperture variability in a two-dimensional framework and fracture matrix interaction are studied to better understand their role in time estimations of aperture growth. The initial phase of karst development is studied from its nascent stage as a fissure into the early stages of turbulence. In uniform fissures in rapidly dissolving minerals, the concentration reaches the solubility limit within a short distance along the flow path. However, the variability in the aperture field inherently provides instabilities to the system and growth is propagated along these perturbations. Flow is focused into preferential channels which are enlarged at a faster rate than surrounding regions of slow flow. As a result, a positive feedback mechanism takes place and creates growth in a highly selective manner. Only in large domains (>25 correlation lengths), can the instabilities create competition for flow at the solution front as well and lead to significant branching. It is this branching which creates the non-monotonic behavior in breakthrough times (defined as the point in which turbulent flow is first encountered). It has been observed that the non-monotonic behavior is scale dependent. Smaller domains do not exhibit this behavior because there are only a few correlation lengths between
the fingertip and the lateral domain boundaries. Aperture variability significantly impacts dissolution patterns in a two-dimensional framework. While aperture variability speeds up growth, the inclusion of the porous bedrock can inhibit growth. The porous matrix serving as a large low - conductive reservoir can significantly influence the development of the fracture by slowing down dissolution growth through matrix diffusion. In a one dimensional model, this issue is further explored. Although the focus of the study is on modeling of early karstification, there are many common themes between this problem and other reactive transport problems that this model can be made suitable for exploring.


Basic processes and mechanisms governing the evolution of karst, 2003, Dreybrodt W, Gabrovek F.

Models of karstification based on the physics of fluid flow in fractures of soluble rock, and the physical chemistry of dissolution of limestone by CO2 containing water have been presented during the last two decades. This paper gives a review of the basic principles of such models, their most important results, and future perspectives.
The basic element of evolving karst systems is a single isolated fracture, where a constant hydraulic head drives calcite aggressive water from the input to the output. Non linear dissolution kinetics with order n = 4 induce a positive feedback by which dissolutional widening at the exit enhances flow rates thus increasing widening and so on until flow rates increase dramatically in a breakthrough event. After this the hydraulic head breaks down and widening of the fracture proceeds fast but even along its entire length under conditions of constant recharge. The significance of modelling such a single fracture results from the fact that an equation for the breakthrough time specifies the parameters determining the processes of early karstification. In a next step the boundary conditions for isolated fractures are varied by including different lithologies of the rock, expressed by different dissolution kinetics. This can enhance or retard karstification. Subterranean sources of CO2 can also be simulated by changing the equilibrium concentration of the solution at the point where CO2 is injected. This leads to accelerated karstification. At the confluence of solutions from two isolated tubes into a third one, mixing corrosion can release free carbon dioxide. Its effect to solutional widening in such a system of three conduits is discussed.
Although these simple models give interesting insights into karst processes more realistic models are required. Combining single fractures into two-dimensional networks models of karst in its dimensions of length and breadth under constant head conditions are presented. In first steps the Ford-Ewers' high-dip and low-dip models are simulated. Their results agree to what one expects from field observations. Including varying lithologies produces a variety of new features. Finally we show that mixing corrosion has a strong impact on cave evolution. By this effect micro climatic conditions in the catchment area of the cave exert significant influence. A common feature in the evolution of such two-dimensional models is the competition of various possible pathways to achieve breakthrough first. Varying conditions in lithologies, carbon dioxide injection or changing hydrological boundary conditions change the chances for the competing conduits.
Karst systems developing at steep cliffs in the dimensions of length and depth are characterized by unconfined aquifers with constant recharge to the water table. Modelling of such systems shows that dissolution of limestone occurs close to the water table. The widening of the fractures there causes lowering of the water table until it becomes stable when base level is reached, and a water table cave grows headwards into the aquifer. When prominent deep fractures with large aperture widths are present deep phreatic loops originate below the water table. A river or a lake on a karst plateau imposes constant head conditions at this location in addition to the constant recharge from meteoric precipitation. In this case a breakthrough cave system evolves along the water table kept stable by the constant head input. But simultaneously deep phreatic loops arise below it.
In conclusion we find that all cave theories such as those of Swinnerton (1932), Rhoades and Sinacori (1941), and the Four-state-model of Ford are reconciled. They are not contradictory but they result from the same physics and chemistry under different boundary conditions


Geophysical evidence for karst formation associated with offshore groundwater transport: An example from North Carolina, 2003, Evans Rl,
Marine geophysical data from Long Bay, North Carolina, involving a novel combination of electromagnetic and high-resolution Chirp seismics, show evidence of submarine karst formation associated with what has been inferred to be a site of high-flux submarine groundwater discharge (SGD) a substantial distance offshore. Recently observed temperature and chemical signals from wells in this area provide the basis for the interpretation of the high-flux SGD here, and they also suggest a terrestrial source for the groundwater and thus a potentially important route for nutrient transport to the oceans. Our data indicate that karstification is localized to the high-flux zone, and we suggest that mixing of the chemically distinct (but saline) groundwater with seawater has resulted in the karstification. As karstification increases permeability and flux, a positive feedback would tend to progressively enhance submarine groundwater discharge. Our data reveal a significant local anomaly in apparent porosity: a dense block that may have initiated the local focusing of groundwater flow. Conditions favorable to the formation of similar locally punctuated sites of high-flux SGD are likely to exist along the mid to inner shelf of the southeastern United States, where carbonate aquifers are prevalent

Geophysical evidence for karst formation associated with offshore groundwater transport: An example from North Carolina, 2003, Evans Rob L. , Lizarralde Dan

Marine geophysical data from Long Bay, North Carolina, involving a novel combination of electromagnetic and high-resolution Chirp seismics, show evidence of submarine karst formation associated with what has been inferred to be a site of high-flux submarine groundwater discharge (SGD) a substantial distance offshore. Recently observed temperature and chemical signals from wells in this area provide the basis for the interpretation of the high-flux SGD here, and they also suggest a terrestrial source for the groundwater and thus a potentially important route for nutrient transport to the oceans. Our data indicate that karstification is localized to the high-flux zone, and we suggest that mixing of the chemically distinct (but saline) groundwater with seawater has resulted in the karstification. As karstification increases permeability and flux, a positive feedback would tend to progressively enhance submarine groundwater discharge. Our data reveal a significant local anomaly in apparent porosity: a dense block that may have initiated the local focusing of groundwater flow. Conditions favorable to the formation of similar locally punctuated sites of high-flux SGD are likely to exist along the mid to inner shelf of the southeastern United States, where carbonate aquifers are prevalent


Modeling the evolution of karst aquifers and speleogenesis. The step from 1-dimensional to 2-dimensional modeling domains, 2004, Romanov D. , Gabrovsek F. , Dreybrodt W.

First models of karst evolution considered a single isolated fracture with no loss of flow along its entire length. Under conditions of constant head dissolution of limestone creates a positive feedback-loop of increase of aperture widths and flow until at breakthrough the flow and aperture width are enhanced dramatically. If a second dimension is added to this model domain, in the simplest case by an exit-tube connected to the isolated channel, water loss from the isolated channel occurs. We have investigated the influence of the water loss on the breakthrough time of the single channel. In all cases, when water loss is present, more aggressive solution enters at the input. The aggressive solutional activity penetrates deeper along the conduit. Therefore dissolutional widening at the exit is enhanced and breakthrough times are reduced. This is discussed in detail by investigating the profiles of hydraulic head, flow rates, aperture widths, and calcium concentrations along the conduit as they evolve in time and comparing them to those of the isolated 1-D conduit.
In a further step the 1-D conduit is embedded into a net of fractures with smaller aperture widths. The conduit is located in the center of the rectangular domain and connected to the 2-D net at equally spaced nodes. By this way exchange flow from the conduit into the net can arise. But also flow from the net to the conduit is possible. We have studied the evolution of this aquifer considering dissolution also in the network of the narrow fissures. Flow from the main central fracture into the net again reduces breakthrough times. After breakthrough, however, a complex exit fan evolves in the net, which later on is overprinted by a net of entrance fans propagating down flow. These fans are related to flow from the net into the central fracture. The evolution of these fans resulting finally in a maze-like structure is significant for high hydraulic gradients (i0.1) as they exist at artificial dam sites. For such situations realistic modeling has to include dissolutional widening in the net. For low hydraulic gradients, i<0.03, the evolution in the net is slow compared to that of the central conduit and therefore the aquifer is dominated by the evolution of the central fracture.


Palaeo-climate reconstruction from stable isotope variations in speleothems: a review, 2004, Mcdermott, F.

Speleothems are now regarded as valuable archives of climatic conditions on the continents, offering a number of advantages relative to other continental climate proxy recorders such as lake sediments and peat cores. They are ideal materials for precise U-series dating, yielding ages in calendar years, thereby circumventing the radiocarbon calibration problems associated with most other continental records. Stable isotope studies in speleothems have shifted away from attempting to provide palaeo-temperature reconstructions to the attainable goal of providing precise estimates for the timing and duration of major O isotope-defined climatic events characterised by high signal to noise ratios (e.g. glacial/interglacial transitions, Dansgaard–Oeschger oscillations, the ‘8200- year’ event). Unlike the marine records, speleothem data sets are not ‘tuned’, and their independent chronology offers opportunities to critically assess leads and lags in the climate system, that in turn can provide important insights into forcing and feedback mechanisms. Improved procedures for the extraction and measurement of stable isotope ratios in fluid inclusions trapped in speleothems are likely to provide, in the near future, a much enhanced basis for the quantitative interpretation of O isotope ratios in speleothem calcite. The latter developments open up once again the tantalising prospect of palaeo-temperature estimates, but more importantly perhaps, provide a direct test for a new generation of general circulation models whose hydrological cycles will incorporate the ‘water isotopes’. The literature is reviewed briefly to provide for the reader a sense of the current state-of-the-art, and to provide some pointers for future research directions


Conceptualisation of speleogenesis in multi-storey artesian systems: a model of transverse speleogenesis., 2005, Klimchouk A.
Conceptual and respective quantitative models of speleogenesis/karstification developed for unconfined aquifers do not adequately represent speleogenesis in confined settings. A conceptual model for speleogenesis in confined settings is suggested, based on views about hydraulic continuity in artesian basins and close cross-formation communication between aquifers in multi-storey artesian systems. Soluble units sandwiched between insoluble porous/fissured formations (common aquifers) initially serve as low permeability beds separating aquifers in a confined system. Conduits evolve as result of vertical hydraulic communication between aquifers across the soluble bed ("transverse speleogenesis"). Recharge from the adjacent aquifer is dispersed and uniform, and flow paths across the soluble bed are rather short. There is a specific hydrogeologic mechanism inherent in artesian transverse speleogenesis (restricted input/output) that suppresses the positive flow-dissolution feedback and hence speleogenetic competition in fissure networks, and accounts for the development of more pervasive channelling in confined settings, of maze patterns where appropriate structural prerequisites exist. This is the fundamental cause for the distinctions between cave morphologies evolving in unconfined and confined aquifers and for eventual distinctions of karstic permeability, storage characteristics and flow system behaviour between the two types of aquifers. Passage network density (the ratio of the cave length to the area of the cave field, km/km2) and cave porosity (a fraction of the volume of a cave block, occupied by mapped cavities) are roughly one order of magnitude greater in confined settings than in unconfined. Average areal coverage (a fraction of the area of the cave field occupied by passages in a plan view) is about 5 times greater in confined settings. Conduit permeability in unconfined settings tends to be highly heterogeneous, whereas it is more homogeneous in confined settings. The storage characteristics of confined karstified aquifers are much greater. Recognition of the differences between origin, organisation and behaviour of karst systems evolved in unconfined and confined settings can improve efficiency of exploration and management of various resources in karst regions and adequacy of assessment of karst-related hazards.

Dissolution of limestone fractures by cooling waters: Early development of hypogene karst systems, 2005, Andre Bj, Rajaram H,

[1] Fracture dissolution in the early stages of karstification under hypogene conditions is investigated using a coupled numerical model of fluid flow, heat transfer, and reactive transport. Dissolution of calcite in the H2O-CO2-CaCO3 system along a cooling flow path is investigated using both equilibrium and kinetic models. During the very early stages of fracture growth, there is a positive feedback between flow, heat transfer, and dissolution. In this stage the dissolution rate is largely controlled by the retrograde solubility of calcite, and aperture growth is relatively uniform along the fracture length. There is a period of slow continuous increase in the mass flow rate through the fracture, which is followed by an abrupt rapid increase. We refer to the time when this rapid increase occurs as the maturation time. As the flow rate continues to increase after maturation, forced convective effects lead to higher fluid temperatures in the fracture, resulting in a negative feedback that slows the rate of fracture growth. The behavior of aperture growth before the maturation time can be described by a simple ordinary differential equation. The solution of this differential equation provides an estimate of the maturation time, in terms of the initial aperture, hydraulic and thermal gradients, and the change in solubility with temperature. The behavior before maturation in two-dimensional variable aperture fractures is investigated using a simplified model. The maturation time is shown to decrease with the degree of aperture variability due to highly selective growth along preferential flow paths


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