Community news

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 casing joint is welded or threaded connection for tubular casing [16].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
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;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for cenozoic (Keyword) returned 51 results for the whole karstbase:
Showing 1 to 15 of 51
Cenozoic deposits of southeastern New Mexico and an outline of the history of evaporite dissolution, 1976, Bachman G. O.

Biogeographical and Paleobiogeographical Problems in Stenasellids (Crustacea Isopoda Asellota of Underground Waters)., 1981, Magniez Guy
Considering their systematic isolation among present Asellota, their strong burrowing behaviour, their aptitude for interstitial life and their wide north-tropical present distribution, the history of Stenasellid Crustaceans seems to be marked by the antiquity of their settlements in continental groundwaters (Middle Cretaceous period?) and a long stage of life in phreatic waters on permanently emerged paleotropical continents during the Cenozoic Era. The resemblance between some forms of the Guinean shield and Mexico sets the problem of the anteriority of their continental conquest to South Atlantic drift. The repartition of Mediterranean European forms appears as a consequence of paleogeographical changes in Tertiary Times. The distribution of continental European forms has been marked by Quaternary climatic alterations: severe curtailment of settlements, endemicity in Glacial periods but wide Holocene expansion for the forms adapted to new climatic conditions.

Une morphologie karstique typique en zone intertropicale : les karsts du Bas Zare, 1985, Quinif, Y.
A TYPICAL MORPHOLOGY OF TROPICAL KARSTS: THE KWILU BASIN IN THE LOWER-ZAIRE - The Kwilu basin, in the region of Bas-Zaire, shows typical landscapes of tropical karsts: cone and tower karsts shaped in precambrian limestones of the "Groupe schisto-calcaire". These precambrian series are little tectonised. They are covered with cenozoic formations which are important in the evolution of the karst. Different types of cavities are studied and replaced in the morphostructural context: old caves, originating in phreatic zone and now cut by the erosion, river streams in tunnel-caves, network under the water table. The superficial forms are interpreted as successive evolutive steps: dissection of a surface (morphological or structural) by a dendritic hydrographic network, birth of a cone-karst being transformed in tower-karst overlooking a new surface. We insist on the morphogenetic importance of the paleoclimatic changes and on the existence of an intertropical karstic morphology in stable craton.

Prsentation du Causse Comtal (Aveyron), 1987, Solier, P.
THE " CAUSSE COMTAL " (AVEYRON, FRANCE): GEOLOGY, HYDROGEOLOGY AND INVENTORY OF MAIN CAVES - The " Causse Comtal " (S = 265 km2) forms a sedimentary bridge between the " Causses du Quercy " in the west and the " Grands Causses " in the east. With a middle humid climate (P = 1000 mm/y, T = 9,4 C, Evap. = 450-500 mm/y), this plateau karst presents two aquifer levels in the Lower and Middle Jurassic separated by a marly layer. These formations cover a paleozoic basement (sandstone, argillite from Carboniferous and Permian, crystalline rocks). The hydrogeological basins are controlled by E-W reverse faults due to the N-S pyrenean compression. The main spring is near Salles-la-Source in the western part (average discharge: 840 l/s; flood : 10 m3/s); it drains a 50-55 km2 area. The morphological and speleological evolution is subordinated to an erosion surface from Upper Cretaceous - Tertiary. Often stopped up (blocking), the numerous fossil caves probably date from the end of Cenozoic era. The large subterranean passages (active or semi-actives galleries; ex.: Tindoul de la Vayssire) are plio-quaternary.

Petrogenesis of Cenozoic, temperate water calcarenites, South Australia; a model for meteoric/shallow burial diagenesis of shallow water calcite sediments, 1989, James Noel P. , Bone Yvonne,

GENERAL CENOZOIC EVOLUTION OF THE MALDIVES CARBONATE SYSTEM (EQUATORIAL INDIAN-OCEAN), 1992, Aubert O, Droxler Aw,
Analyses and interpretation of an industrial multi-channel seismic grid, a 2.3 km-deep industrial well (NMA-1) and two ODP (Sites 715 and 716), have generated new insights into the evolution of the Maldives carbonate system, Equatorial Indian Ocean. The present physiography of the Maldives Archipelago, a double chain of atolls delineating an internal basin, corresponds only to the latest phase of a long and dynamic evolution, far more complex than the simple vertical build-up of reef caps on top of thermally subsiding volcanic edifices. Through the Cenozoic evolution of the Maldives carbonate system, distinct phases of vertical growth (aggradation), exposure, regional or local drowning, and recovery of the shallow banks by lateral growth (progradation) have been recognized. The volcanic basement underlying the Maldives Archipelago is interpreted to be part of a volcanic ridge generated by the northern drift of the Indian plate on top of the hotspot of the island of Reunion. The volcanic basement recovered at well NMA-1 and ODP Site 715 has been radiometrically dated as 57.2 1.8 Ma (late Paleocene) by 40Ar-39Ar. Seismic and magnetic data indicate that this volcanic basement has been affected by a series of NNE-SSW trending subvertical faults, possibly associated with an early Eocene strike-slip motion along an old transform zone. The structural topography of the volcanic basement apprears to have dictated the initial geometry of the Eocene and early Oligocene Maldives carbonate system. Biostratigraphic analyses of samples, recovered by drilling in Site 715 and exploration well NMA-1, show that the Maldives shallow carbonate system was initiated during the early Eocene on top of what were originally subaerial volcanic edifices. The Eocene shallow carbonate sequence, directly overlying the volcanic basement at NMA-1, is dolomitized and remains neritic in nature, suggesting low subsidence rates until the early Oligocene. During this first phase of the Maldives carbonate system evolution, shallow carbonate facies aggraded on top of basement highs and thick deep-water periplatform sediments were deposited in some central seaways, precursors of the current wider internal basins. In the middle Oligocene, a plate reorganization of the equatorial Indian Ocean resulted in the segmentation of the hotspot trace and the spreading of the Maldives away from the transform zone. This plate reorganization resulted in increasing subsidence rates at NMA-1, interpreted to be associated with thermal cooling of the volcanic basement underlying the Maldives carbonate system. This middle Oligocene event also coincides with a regional irregular topographic surface, considered to represent a karst surface produced by a major low-stand. Deep-water carbonate facies, as seen in cuttings from NMA-1, overlie the shallow-water facies beneath the karst surface which can, therefore, be interpreted as a drowning unconformity. In the late Oligocene, following this regional deepening event, one single central basin developed, wider than its Eocene counterparts, and the current intraplatform basin was established. Since the early to middle Miocene, the shallow carbonate facies underwent a stage of local recovery by progradation of neritic environments towards the central basin. The simultaneous onset in the early middle Miocene of the monsoonal wind regime may explain the development of bidirectional slope progradations in the Maldives. During the late Miocene and the early Pliocene, several carbonate banks were locally drowned, whereas others (i.e. Male atoll) display well-developed lateral growth through margin progradations during the same interval. Differential carbonate productivity among the atolls could explain these diverse bank responses. High-frequency glacialeustatic sea-level fluctuations in the late Pliocene and Pleistocene resulted in periodic intervals of bank exposure and flooding, and developed the present-day physiography of atolls, with numerous faros along their rims and within their lagoons

A tentative classification of paleoweathering formations based on geomorphological criteria, 1996, Battiauqueney Y,
A geomorphological classification is proposed that emphasizes the usefulness of paleoweathering records in any reconstruction of past landscapes. Four main paleoweathering records are recognized: 1. Paleoweathering formations buried beneath a sedimentary or volcanic cover. Most of them are saprolites, sometimes with preserved overlying soils. Ages range from Archean to late Cenozoic times; 2. Paleoweathering formations trapped in karst: some of them have buried pre-existent karst landforms, others have developed simultaneously with the subjacent karst; 3. Relict paleoweathering formations: although inherited, they belong to the present landscape. Some of them are indurated (duricrusts, silcretes, ferricretes,...); others are not and owe their preservation to a stable morphotectonic environment; 4. Polyphased weathering mantles: weathering has taken place in changing geochemical conditions. After examples of each type are provided, the paper considers the relations between chemical weathering and landform development. The climatic significance of paleoweathering formations is discussed. Some remote morphogenic systems have no present equivalent. It is doubtful that chemical weathering alone might lead to widespread planation surfaces. Moreover, classical theories based on sea-level and rivers as the main factors of erosion are not really adequate to explain the observed landscapes

Age and Origin of Carlsbad Cavern and Related Caves from 40Ar/39Ar of Alunite., 1998, Polyak V. J. , Mcintosh W. C. , Given N. , Provencio P.
40Ar/39Ar dating of fine-grained alunite that formed during cave genesis provides ages of formation for the Big Room level of Carlsbad Cavern [4.0 to 3.9 million years ago (Ma)], the upper level of Lechuguilla Cave (6.0 to 5.7 Ma), and three other hypogene caves (11.3 to 6.0 Ma) in the Guadalupe Mountains of New Mexico. Alunite ages increase and are strongly correlative with cave elevations, which indicates an 1100-meter decline in the water table, apparently related to tectonic uplift and tilting, from 11.3 Ma to the present. 40Ar/39Ar dating studies of the hypogene caves have the potential to help resolve late Cenozoic climatic, speleologic, and tectonic questions.

Determination of escarpment age using morphologic analysis: An example from the Galilee, northern Israel, 2000, Matmon A. , Zilberman E. , Enzel Y. ,
We used topographic and structural data and very limited age control to perform quantitative morphometric analyses and to determine relative ages of escarpments bounded by late Cenozoic normal faults in the Galilee, Israel. The Galilee is an extensional zone composed of a series of uplifted and tilted blocks forming large escarpments built mainly of carbonate rocks. Two parameters used to discriminate tectonic stages are the ratio between the height of the escarpment and the total stratigraphic displacement (L) and the degree of concavity of escarpment slopes relative to a reference slope. The only dated reference slope is Mount Tur'an, [~]300 m high and formed by the Tur'an fault system, which has a total stratigraphic displacement of 625 m. A basalt flow that delimits the age of the Tur'an escarpment is dated to 4.23 {} 0.23 Ma and displaced 300 m, which is identical to the present-day topographic expression of this escarpment. The L value for this escarpment is [~]0.5. The Tur'an fault system was active prior to 4.23 Ma at slow uplift rates that enabled erosion to maintain the gentle slope over which the basalt flowed. Increased offset rates following the basalt extrusion led to the formation of the escarpment. The preservation of the basalt at the top of the escarpment indicates that erosional lowering of the upper surface of the Tur'an block has been minor since its formation. The L values indicate two stages of uplift; an early stage during which offset rates were probably low enough that they did not form topography, and a later stage that formed topography, which is preserved. The timing of the change in displacement rates from a slow continuous stage to a fast, topography-forming stage was determined by comparing the shape of the dated slope of Tur'an to that of other slopes. We conclude the following: (1) generally, the topographic profiles of different parts of each individual escarpment have similar shapes indicating similar ages; (2) escarpments having slopes that are more concave or convex than the reference Tur'an escarpment are older or younger than 4 Ma, respectively; and (3) the Galilee escarpments did not form simultaneously. A few escarpments were already major morphologic features by the early to middle Pliocene, whereas the rest formed during the late Pliocene. Morphometric analysis is a useful method for studying the geologic history of a landscape controlled by normal fault uplift and characterized by the absence of sediment deposition and where carbonate dissolution is the main erosional process. This and similar approaches can be used to discriminate tectonic stages and understand the relationship between tectonic activity and surface processes in other extensional regions

Porosity and permeability enhancement in unconfined carbonate aquifers as a result of solution, 2000, Worthington S. R. H. , Ford D. C. , Beddows P. A.
Solution processes in unconfined carbonate aquifers result in a network of channels. We examine four contrasting carbonate aquifers, in Paleozoic dolostone, Paleozoic limestone, Mesozoic chalk, and Cenozoic limestone, to characterize the enhancement of porosity and permeability by dissolution. In all four cases the channels add little to the porosity, but enhance the permeability of the fractured rock by one to three orders of magnitude. Similar porosity and permeability changes are predicted for all unconfined carbonate aquifers, in both dolostones and limestones, in both allogenic and autogenic settings, and in carbonates of all ages.

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.

Baiyun cave in Naigu Shilin, Yunnan karst, China, 2001, Sebela S. , Slabe T. , Kogovsek J. , Liu H. , Pruner P. ,
The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming, Yunnan Province, China. The prevailing orientations of the cave passages are N110 degrees -120 degreesE and NO degrees -IO degreesW and those of the fissures in the cave are N30 degrees -40 degreesW and N20 degrees -30 degreesW. The cave is developed in the thick-bedded Lower Permian Qixia Formation. The cave has an active water flow and is currently at the near water-table stage. There are large amounts of different infills of cave sediments. The cave shows different stages of paragenesis. The palaeomagnetic analysis of cave sediments shows that their ages are younger than 780 ka B.P. (the Brunhes Chron). The upper part of the sampled profile belongs to the reverse Blake event (112.3-117.9 ka B.P.). The formation of the Baiyun cave is directly connected with the development of the Naigu Shilin. The formation of karst underground and surface features depends on the regional tectonic deformation and the Cenozoic extension of the study area

Recent active faults in Belgian Ardenne revealed in Rochefort Karstic network (Namur Province, Belgium), 2001, Vandycke S. , Quinif Y. ,
This paper presents observations of recent faulting activity in the karstic network of the Rochefort Cave (Namur Province, Belgium, Europe). The principal recent tectonic features are bedding planes reactivated as normal faults, neo-formatted normal faults in calcite flowstone, fresh scaling, extensional features, fallen blocks and displacement of karstic tube. The seismotectonic aspect is expanded by the presence of fallen blocks where normally the cavity must be very stable and in equilibrium. Three main N 070degrees fault planes and a minor one affect, at a decimetre scale, the karst features and morphology. The faults are still active because recent fresh scaling and fallen blocks are observable. The breaking of Holocene soda straw stalactites and displacements of artificial features observed since the beginning of the tourist activity, in the last century, also suggest very recent reactivation of these faults. This recent faulting can be correlated to present-day tectonic activity, already evidenced by earthquakes in the neighbouring area. Therefore, karstic caves are favourable sites for the observation and the quantification of recent tectonic activity because they constitute a 3-D framework, protected from erosion. Fault planes with this recent faulting present slickensides. Thus a quantitative analysis in term of stress inversion, with the help of striated faults, has permitted to reconstruct the stress tensor responsible for the brittle deformation. The principal NW-SE extension (sigma(3) horizontal) is nearly perpendicular to that of the present regional stress as illustrated by the analysis of the last strong regional earthquake (Roermond, The Netherlands) in 1992. During the Meso-Cenozoic, the main stress tectonics recorded in this part of the European platform is similar to the present one with a NE-SW direction of extension. The discrepancy between the regional stress field and the local stress in the Rochefort cave can be the result of the inversion of the sigma(2) and sigma(3) axes of the stress ellipsoid due to its symmetry or of a local modification at the ground surface of the crustal stress field as it has been already observed in active zones

Characteristics of porosity and permeability enhancement in unconfined carbonate aquifers due to the development of dissolutional channel systems., 2001, Worthington S. R. H. , Ford D. C. , Beddows P. A.
Dissolution processes in unconfmed carbonate aquifers result in the creation of networks of channels. We examine four contrasting carbonate aquifers, in Paleozoic dolostone, Paleozoic limestone, Mesozoic chalk, and Cenozoic limestone, to characterize the enhancement of porosity and permeability produced by this dissolution. In all four cases the channels are found to add little to the porosity, but enhance the permeability of the fractured rock by one to three orders of magnitude. Similar porosity and permeability changes are predicted for all unconfmed carbonate aquifers, in both dolostones and limestones, in both allogenic and autogenic settings, and in carbonates of all ages.

Geohazard map of cover-collapse sinkholes in the 'Tournaisis' area, southern Belgium, 2002, Kaufmann O. , Quinif Y. ,
This paper reports the methodology developed to draw up a geohazard map of cover-collapse sinkhole occurrences in the 'Toumaisis' area. In this area, Carboniferous limestones are overlain by a Mesocenozoic cover, mainly consisting of marls, sand and clay. The thickness of this cover ranges from a few meters to more than 100 m. The surficial morphology of the area does not show any karstic evidence except for the occurrence of these collapses. From a paleogeographical point of view, a developed quaternary karst is not conceivable in the area. Recent works suggested that the collapses are set off from reactivated paleokarsts. The paleokarsts studied in the area proved to be the result of a particular weathering of the limestone. The organization of these paleokarsts seems very low and mainly guided by the limestone fracturing. As for most induced sinkholes, the reactivation of these paleokarsts is linked to the lowering of piezometric heads. In most of the area, a thick cover and intensive land use mask potential surface hints of the buried paleokarsts and of the fracturing of the bedrock. Aerial photographs and remote sensing techniques have therefore shown little results in delineating collapse hazard zones up to now. The study of the surficial morphology is also of little help. In order to draw up the geohazard map in such a difficult context, hydrogeological data and geological mapping information could only be used. These informations are based on a limited number of boreholes and piezometers and are thus, only valid on a regional scale. Records of former collapses were also available. These records were of great interest since sinkhole distribution is obviously clustered in the area. Bedrock roof and cover formation floor altitudes were digitized and adapted to produce digital thematic maps. Piezometric heads were imported from a calibrated groundwater model of the aquifer. These data and a digital elevation model of the area were integrated into a geographical information system (GIs) to produce a coherent 3-D description of the area on a regional scale. Parameters such as the dewatering of the limestone and the thickness of the cover formation where sinkholes occurred were then estimated. Density of former collapses was also computed. This showed that zones of high sinkhole occurrence coincide with zones of heavy lowering of piezometric heads. Combining the density of former collapses with the dewatering of the limestone enabled us to delineate zones of low, moderate and high collapse hazard. (C) 2002 Elsevier Science B.V. All rights reserved

Results 1 to 15 of 51
You probably didn't submit anything to search for