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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. ...

Did you know?

That sulfide minerals is minerals that are composed of one or more metals combined with sulphur. the most common is pyrite. they are believed to be produced by the metabolic action of micro-organisms, and are found in many sedimentary rocks, usually in trace amounts.?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Featured articles from other Geoscience Journals
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
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
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 sulfuric acid (Keyword) returned 86 results for the whole karstbase:
Showing 16 to 30 of 86
Hydrothermal speleogenesis in the Hungarian karst, 2000, Dublyansky Y. V.
Hydrothermal karst caves in Hungary were formed in a variety of speleogenetic settings. The oldest small solutional cavities (vugs) were formed in the deep-seated low-gradient zone at temperatures in excess of 90 oC. The temperatures decreased with time, as inferred from fluid inclusion studies of cave calcite. The caves were formed by normal carbonate corrosion. Large two-dimensional mazes of the Buda Hills were formed in the shallow low-temperature (but still hydrothermal) setting. The leading speleogenetic processes were normal carbonate corrosion (including mixing/cooling corrosion) and sulfuric acid corrosion. Temperatures at this stage were lower: ca. 50 oC and less. Above the thermal water table, in the subaerial zone, some specific and powerful speleogenetic processes occurred; condensation corrosion (by CO2-bearing waters) and replacement corrosion involving sulfuric acid reactions. Three-dimensional bush-like caves composed of connected spherical niches were formed as the result of this subaerial karstification.

Sulfuric acid, hypogene karst in the Guadalupe mountains of New Mexico and West Texas, USA, 2000, Hill C. A.
Carlsbad Cavern, Lechuguilla Cave, and other caves in the Guadalupe Mountains are probably the worlds best examples of karst formed by sulfuric acid in a hypogene setting. Four episodes of karstification have occurred in these mountains from Late Permian time to the present, the sulfuric acid episode being the last of these four. Sulfuric acid karst can be recognized by its large passage size, ramiform-spongework pattern, horizontal passages connected by deep pits and fissures, location beneath structural and stratigraphic traps, gypsum and native sulfur deposits, and the sulfuric-acid/H2S indicator minerals endellite, alunite, natroalunite, and tyuyamunite. Guadalupe caves formed in a diffuse-flow aquifer regime where caves may have acted as mixing chambers for hypogene-derived H2S and meteoric-derived fresh water. How cave hydrology has been related to regional hydrology during the late-Tertiary to present is poorly understood. Sulfuric acid karst is an integral part of H2S-degassing hydrocarbon basins which also can contain economic sulfur and Mississippi Valley-type ore deposits.

Some case studies of speleogenesis by sulfuric acid, 2000, Lowe D. J. , Bottrell S. H. , Gunn J.
Minerals that can weather to produce sulfuric acid directly or indirectly, with or without microbial mediation, occur as trace components in most carbonate sequences, but they are more concentrated at specific horizons. The latter comprise beds of atypical lithology, together termed inception horizons, and they are commonly associated with breaks between major depositional cycles. Some cycle boundaries are marked by concentrations of sulfide minerals, particularly pyrite, that are readily oxidized to generate sulfuric acid. Cycle boundaries may also be marked by the presence of primary evaporite minerals such as gypsum, and their removal by direct dissolution or by their reduction to hydrogen sulfide may be implicated in early porosity development. Though few caves in carbonate sequences are largely, or entirely, the product of calcite dissolution by sulfuric acid or of evaporite removal, such processes may play an important role in cave inception. This chapter examines a number of situations where processes other than carbonic acid dissolution have played an important role in secondary porosity generation and influenced subsequent speleogenesis.

Hydrogeologic control of cave patterns, 2000, Palmer A. N.
Cave patterns are controlled by a hierarchy of hydrogeologic factors. The location and overall trend of a cave depends on the distribution of recharge and discharge points within the karst aquifer. Specific cave patterns, i.e. branchwork vs. maze patterns, are controlled mainly by the nature of the groundwater recharge. Individual passage configurations are determined by the structural nature of the bedrock and by the geomorphic evolution of the aquifer. The origin of branchwork caves is favored by point recharge sources of limited catchment area. Floodwater recharge, especially through sinking streams, tends to produce maze caves or local mazes superimposed on branchwork caves. Through floodwater activity, anastomotic mazes form in prominently bedded aquifers, network mazes in prominently fractured aquifers, and spongework mazes in highly porous or brecciated rocks. Epikarst, network caves, and spongework caves are also produced by diffuse or dispersed infiltration into the karst aquifer, and network and spongework caves can be the product of mixing of two waters of contrasting chemistry. Ramiform caves are produced most often by rising water rich in hydrogen sulfide, which oxidizes to sulfuric acid. Deep-seated processes that help to initiate cave development include the interaction between carbonates and sulfates, which can greatly increase the solubility of dolomite, gypsum, and anhydrite, while calcite precipitates. Although tightly confined artesian conditions have long been associated with the origin of maze caves, they actually have no inherent tendency to form mazes. The slow movement of groundwater close to equilibrium with dissolved bedrock, typical of tightly confined artesian aquifers, is the least favorable setting for maze development.

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.

Geomicrobiology of caves: A review, 2001, Northup D. E. , Lavoie K. H. ,
In this article, we provide a review of geomicrobiological interactions in caves, which are nutrient-limited environments containing a variety of redox interfaces. Interactions of cave microorganisms and mineral environments lead to the dissolution of, or precipitation on, host rock and speleothems (secondary mineral formations). Metabolic processes of sulfur-, iron-, and manganese-oxidizing bacteria can generate considerable acidity, dissolving cave walls and formations. Examples of possible microbially influenced corrosion include corrosion residues (e.g., Lechuguilla and Spider caves, New Mexico, USA), moonmilk from a number of caves (e.g., Spider Cave, New Mexico, and caves in the Italian Alps), and sulfuric acid speleogenesis and cave enlargement (e.g., Movile Cave, Romania, and Cueva de Villa Luz, Mexico). Precipitation processes in caves, as in surface environments, occur through active or passive processes. In caves, microbially induced mineralization is documented in the formation of carbonates, moonmilk, silicates, clays, iron and manganese oxides, sulfur, and saltpeter at scales ranging from the microscopic to landscape biokarst. Suggestions for future research are given to encourage a move from descriptive, qualitative studies to more experimental studies

The hypogenic caves: a powerful tool for the study of seeps and their environmental effects, 2002, Forti P, Galdenzi S, Sarbu Sm,
Research performed in caves has shown the existence of significant effects of gas seeps, especially CO2 and H2S, within subterranean voids. Carbon dioxide causes important corrosive effects and creates characteristic morphologies (e.g., bell-shaped domes, bubble's trails), but is not involved in the deposition of specific cave minerals. On the other hand, in carbonate environments, hydrogen sulfide when oxidized in the shallow sections of the aquifer generates important corrosion effects and is also responsible for the deposition of specific minerals of which gypsum is the most common.Studies performed in the last few years have shown that H2S seeps in caves are associated with rich and diverse biological communities, consisting of large numbers of endemic species. Stable isotope studies (carbon and nitrogen) have demonstrated that these hypogean ecosystems are entirely based on in situ production of food by chemoautotrophic microorganisms using energy resulting from the oxidation of H2S.Although located only 20 m under the surface, Movile Cave does not receive meteoric waters due to a layer of impermeable clays and loess that covers the Miocene limestone in which the cave is developed. In the Frasassi caves, where certain amounts of meteoric water seep into the limestone, the subterranean ecosystems are still isolated from the surface. As the deep sulfidic waters mix with the oxigenated meteoric waters, sulfuric acid limestone corrosion is accelerated resulting in widespread deposition of gypsum onto the cave walls.Both these caves have raised a lot of interest for biological investigations regarding the chemoautotrophically based ecosystems, demonstrating the possibility of performing such studies in environments that are easily accessible and easy to monitor compared to the deep-sea environments where the first gas seeps were discovered

Gypsum deposits in the Frasassi Caves, central Italy, 2003, Galdenzi, S. , Maruoka, T.
The Frasassi Caves are hypogenic caves in central Italy, where H2S-rich groundwater flows in the lowest cave level. Near the water table, the H2S is converted to sulfuric acid by biotic and abiotic processes, which have enhanced cave development. The sulfate generally deposits above the water table as a replacement gypsum crust coating limestone walls or as large gypsum crystals. Although the oxidation of sulfide also occurs below the water table, sulfate saturation is not achieved, therefore, sulfate does not precipitate below the water table. In the upper dry levels of the cave, three main types of ancient gypsum deposits occurs: (1) replacement crusts, similar to the presently forming deposits of the active zone, (2) microcrystalline large and thick floor deposits, and (3) euhedral crystals inside mud. The study of the depositional setting and the analysis of sulfur isotopes in the gypsum and groundwater clearly demonstrate that all the sampled gypsum in the cave formed by H2S oxidation above the water table. Some fraction of small sulfur isotopic differences between H2S in the water and gypsum can be explained by isotopic fractionation during abiotic and/or biotic oxidation of H2S.

Origin and Significance of Postore Dissolution Collapse Breccias Cemented with Calcite and Barite at the Meikle Gold Deposit, Northern Carlin Trend, Nevada, 2003, Emsbo P, Hofstra Ah,
The final event in a complicated hydrothermal history at the Meikle gold deposit was gold deficient but caused extensive postore dissolution of carbonate, collapse brecciation, and precipitation of calcite and barite crystals in the resulting cavities. Although previously interpreted to be part of the Carlin-type hydrothermal system, crosscutting relationships and U-Th-Pb geochronology constrain this hydrothermal event to late Pliocene time (ca. 2 Ma), nearly 36 Ma after ore formation. Mineralogic, fluid inclusion, and stable isotope data indicate that postore hydrothermal fluids were reduced, H2S-rich, unevolved meteoric waters ({delta}18O = -17{per thousand}) of low temperature (ca. 65{degrees}C). The{delta} 18O values of barite and calcite indicate that these minerals were in isotopic equilibrium, requiring that barite SO4 was derived from the oxidation of reduced sulfur; however, preexisting sulfides in breccia cavities were not oxidized. The{delta} 34S (15{per thousand}) values of barite are higher than those of local bulk sulfide and supergene alunite indicating that SO4 was not derived from supergene oxidation of local sulfide minerals. The 15 per mil {delta}34S value suggests that the H2S in the fluids may have been leached from sulfur-rich organic matter in the local carbonaceous sedimentary rocks. A reduced H2S-rich fluid is also supported by the bright cathodoluminescence of calcite which indicates that it is Mn rich and Fe poor. Calcite has a narrow range of {delta}13C values (0.3-1.8{per thousand}) that are indistinguishable from those of the host Bootstrap limestone, indicating that CO2 in the fluid was from dissolution of the local limestone. These data suggest that dissolution and brecciation of the Bootstrap limestone occurred where H2S-rich fluids encountered more oxidizing fluids and formed sulfuric acid (H2SO4). Intense fracturing in the mine area by previous structural and hydrothermal events probably provided conduits for the descent of oxidized surface water which mixed with the underlying H2S-rich waters to form the dissolving acid. The surface-derived fluid apparently contained sufficient oxygen to produce H2SO4 from H2S but not enough to alter pyrite to Fe oxide. Although H2S is an important gold-transporting ligand, the temperature was too low to transport a significant amount of gold. The presence of analogous calcite- and barite-lined cavities in other Carlin-type deposits suggests that the generation (and oxidation) of H2S-rich meteoric waters was a common phenomenon in north-central Nevada. Previous sulfur isotope studies have also shown that the Paleozoic sedimentary rocks were the principal source of H2S in Devonian sedimentary exhalative-type, Jurassic intrusion-related, Eocene Carlin-type, and Miocene low-sulfidation gold deposits in the region. The similar sulfur source in all of these systems suggests that basin brines, magmatic fluids, and meteoric waters all evolved to be H2S-rich ore fluids by circulation through Paleozoic sedimentary rocks. Thus, although not directly related to gold mineralization, the recent hydrologic history of the deposit provides important clues to earlier ore-forming processes that were responsible for gold mineralization

Condensation on cave walls: Implications for cave enlargement and sulfuric acid speleogenesis, 2003, Engel As, Stern La, Bennett Pc,

Role of fluid mixing in deep dissolution of carbonates, 2003,

The presence of cavities filled with new minerals in carbonate rocks is a common feature in oil reservoirs and lead-zinc deposits. Since groundwater equilibrates rapidly with carbonates, the presence of dissolution cavities in deep carbonate host rocks is a paradox. Two alternative geochemical processes have been proposed to dissolve carbonates at depth: hydrogen sulfide oxidation to sulfuric acid, and metal sulfide precipitation. With the aid of geochemical modeling we show that mixing two warm solutions saturated with carbonate results in a new solution that dissolves limestone. Variations in the proportion of the end-member fluids can also form a supersaturated mixture and fill the cavity with a new generation of carbonate. Mixing is in general more effective in dissolving carbonates than the aforementioned processes. Moreover, mixing is consistent with the wide set of textures and mineral proportions observed in cavity infillings


Microbial contributions to cave formation: New insights into sulfuric acid speleogenesis, 2004, Engel As, Stern La, Bennett Pc,
The sulfuric acid speleogenesis (SAS) model was introduced in the early 1970s from observations of Lower Kane Cave, Wyoming, and was proposed as a cave-enlargement process due to primarily H2S autoxidation to sulfuric acid and subaerial replacement of carbonate by gypsum. Here we present a reexamination of the SAS type locality in which we make use of uniquely applied geochemical and microbiological methods. Little H2S escapes to the cave atmosphere, or is lost by abiotic autoxidation, and instead the primary H2S loss mechanism is by subaqueous sulfur-oxidizing bacterial communities that consume H2S. Filamentous 'Epsilonproteobacteria' and Gammaproteobacteria, characterized by fluorescence in situ hybridization, colonize carbonate surfaces and generate sulfuric acid as a metabolic byproduct. The bacteria focus carbonate dissolution by locally depressing pH, compared to bulk cave waters near equilibrium or slightly supersaturated with calcite. These findings show that SAS occurs in subaqueous environments and potentially at much greater phreatic depths in carbonate aquifers, thereby offering new insights into the microbial roles in subsurface karstification

'Sour gas' hydrothermal jarosite: ancient to modem acid-sulfate mineralization in the southern Rio Grande Rift, 2005, Lueth V. W. , Rye R. O. , Peters L. ,
As many as 29 mining districts along the Rio Grande Rift in southern New Mexico contain Rio Grande Rift-type (RGR) deposits consisting of fluorite-barite sulfide-jarosite, and additional RGR deposits occur to the south in the Basin and Range province near Chihuahua, Mexico. Jarosite occurs in many of these deposits as a late-stage hydrothermal mineral coprecipitated with fluorite, or in veinlets that crosscut barite. In these deposits, many of which are limestone-hosted, jarosite is followed by natrojarosite and is nested within silicified or argillized wallrock and a sequence of fluorite-barite sulfide and late hematite-gypsum. These deposits range in age from similar to 10 to 0.4 Ma on the basis of Ar-40/Ar-39 dating of jarosite. There is a crude north-south distribution of ages, with older deposits concentrated toward the south. Recent deposits also occur in the south, but are confined to the central axis of the rift and are associated with modem geothermal systems. The duration of hydrothermal jarosite mineralization in one of the deposits was approximately 1.0 my. Most Delta(18)O(SO4)-OH values indicate that jarosite precipitated between 80 and 240 degrees C, which is consistent with the range of filling temperatures of fluid inclusions in late fluorite throughout the rift, and in jarosite (180 degrees C) from Pena Blanca, Chihuahua, Mexico. These temperatures, along with mineral occurrence, require that the jarosite have had a hydrothermal origin in a shallow steam-heated environment wherein the low pH necessary for the precipitation of jarosite was achieved by the oxidation of H2S derived from deeper hydrothermal fluids. The jarosite also has high trace-element contents (notably As and F), and the jarosite parental fluids have calculated isotopic signatures similar to those of modem geothermal waters along the southern rift; isotopic values range from those typical of meteoric water to those of deep brine that has been shown to form from the dissolution of Permian evaporite by deeply circulating meteoric water. Jarosite delta(34)S values range from -24 parts per thousand to 5 parts per thousand, overlapping the values for barite and gypsum at the high end of the range and for sulfides at the low end. Most delta(34)S values for barite are 10.6 parts per thousand to 13.1 parts per thousand and many delta(34)S values for gypsum range from 13.1 parts per thousand to 13.9 parts per thousand indicating that a component of aqueous sulfate was derived from Permian evaporites (delta(34)S = 12 2 parts per thousand). The requisite H2SO4 for jarosite formation was derived from oxidation of H2S which was likely largely sour gas derived from the thermochemical reduction of Permian sulfate. The low delta(34)S values for the precursor H2S probably resulted from exchange deeper in the basin with the more abundant Permian SO42-- at similar to 150 to 200 degrees C. Jarosite formed at shallow levels after the PH buffering capacity of the host rock (typically limestone) was neutralized by precipitation of earlier minerals. Some limestone-hosted deposits contain caves that may have been caused by the low pH of the deep basin fluids due to the addition of deep-seated HF and other magmatic gases during periods of renewed rifting. Caves in other deposits may be due to sulfuric acid speleogenesis as a result of H2S incursion into oxygenated groundwaters. The isotopic data in these 'sour gas' jarosite occurrences encode a recod of episodic tectonic or hydrologic processes that have operated in the rift over the last 10 my. (c) 2004 Elsevier B.V. All rights reserved

Dominant Microbial Populations in Limestone-Corroding Stream Biofilms, Frasassi Cave System, Italy, 2006, Macalady Jennifer L. , Lyon Ezra H. , Koffman Bess, Albertson Lindsey K. , Meyer Katja, Galdenzi Sandro, Mariani Sandro,
Waters from an extensive sulfide-rich aquifer emerge in the Frasassi cave system, where they mix with oxygen-rich percolating water and cave air over a large surface area. The actively forming cave complex hosts a microbial community, including conspicuous white biofilms coating surfaces in cave streams, that is isolated from surface sources of C and N. Two distinct biofilm morphologies were observed in the streams over a 4-year period. Bacterial 16S rDNA libraries were constructed from samples of each biofilm type collected from Grotta Sulfurea in 2002. {beta}-, {gamma}-, {delta}-, and {varepsilon}-proteobacteria in sulfur-cycling clades accounted for [≥]75% of clones in both biofilms. Sulfate-reducing and sulfur-disproportionating {delta}-proteobacterial sequences in the clone libraries were abundant and diverse (34% of phylotypes). Biofilm samples of both types were later collected at the same location and at an additional sample site in Ramo Sulfureo and examined, using fluorescence in situ hybridization (FISH). The biomass of all six stream biofilms was dominated by filamentous {gamma}-proteobacteria with Beggiatoa-like and/or Thiothrix-like cells containing abundant sulfur inclusions. The biomass of {varepsilon}-proteobacteria detected using FISH was consistently small, ranging from 0 to less than 15% of the total biomass. Our results suggest that S cycling within the stream biofilms is an important feature of the cave biogeochemistry. Such cycling represents positive biological feedback to sulfuric acid speleogenesis and related processes that create subsurface porosity in carbonate rocks

Observations from active sulfidic karst systems: Is the present the key to understanding Guadalupe Mountain Speleogenesis?, 2006, Hose L. D. , Macalady J. L.

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