MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology

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 environment is all the external conditions surrounding a living thing [23].?

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 burial (Keyword) returned 103 results for the whole karstbase:
Showing 31 to 45 of 103
Alteration of magnetic properties of Palaeozoic platform carbonate rocks during burial diagenesis (Lower Ordovician sequence, Texas, USA), 1999, Haubold Herbert,
Palaeomagnetic and sedimentological investigations of samples from two sections of correlative Iapetan platform carbonate rocks from Texas, USA, were made to test whether their magnetic properties reflect diagenetic alteration associated with regional and local tectonism. The Honeycut Formation (Llano Uplift area, central Texas), in close proximity to the late Palaeozoic Ouachita orogenic belt, exhibits a distinct correlation between magnetization intensity, magnetization age (direction) and lithofacies. Mudstones preserve their weak primary Early Ordovician magnetization, whereas dolo-grainstones carry a strong Pennsylvanian magnetization residing in authigenic magnetite. Fluid migration associated with the Ouachita Orogeny has been focused in lithofacies with high permeability and caused dolomite recrystallization and pervasive remagnetization. Magnetization intensity trends covary with fluid/rock ratios. However, aquitards were either not affected or less affected by these fluids. Unlike the Honeycut Formation, permeable rocks of the El Paso Group (Franklin Mountains, west Texas) carry only a non-pervasive Pennsylvanian magnetization. Therefore, a larger percentage of El Paso Group samples retain a primary Early Ordovician signature. This area is further removed from the Ouachita front, and, thus, the influence by Pennsylvanian orogenic fluids was less pronounced

Origin and attributes of paleocave carbonate reservoirs, 1999, Loucks R. G.
Paleocave systems form an important class of carbonate reservoirs that are products of near-surface karst processes and later burial compaction and diagenesisOrigins of fractures, breccias, sediment fills and other features associated with paleocave reservoirs have been studied in modem and ancient cave systemsInformation about such cave systems can be used to reconstruct the general evolution of paleocave reservoirs and understand their associated scale, pore networks, and spatial complexities

Age of the Sherman-Type Zn-Pb-Ag Deposits, Mosquito Range, Colorado, 2000, Symons D. T. A. , Lewchuk M. T. , Taylor C. D. , Harris M. J. ,
The Sherman-type Zn-Pb-Ag dolomite deposits in central Colorado are hosted in dolostones of the Early Mississippian Leadville Formation. Paleomagnetic analysis, using progressive alternating field and thermal demagnetization and isothermal remanent magnetization acquisition methods, was performed on specimens from samples at 37 sites in the Sherman-type Continental Chief, Peerless, Ruby, Sacramento, and Sherman deposits, in their host rocks, in the 72 Ma Pando Porphyry sill(s) and in the ~40 Ma Leadville-type Black Cloud massive sulfide deposit. Paleomagnetic fold, contact, and breccia tests were performed to test for the antiquity of the magnetizations. The results are interpreted to indicate that the Leadville carbonates were regionally dolomitized at ~308 {} 6 (1{sigma}) Ma in the Early Pennsylvanian and that the Sherman-type deposits were emplaced at ~272 {} 18 (1{sigma}) Ma during the Early Permian after northeast-trending block faulting, karstification, and ~4 {} 1 km of sedimentary burial, possibly as the result of subsurface gravity-driven fluid flow related to the Ouachita-Marathon orogen. Following late Ouachita-Marathon or earliest Laramide (Late Cretaceous) folding, the remanence in the Sherman-type deposits and the Leadville dolostone rocks within the contact alteration zone of the 72 Ma Pando Porphyry sill(s) was reset to acquire a Late Cretaceous normal characteristic remanent magnetization. Thereafter the Black Cloud Leadville-type massive sulfide deposit was magnetized in the Eocene to acquire a reversed polarity characteristic remanent magnetization that was not found in the Sherman-type deposits

Organic geochemistry of paleokarst-hosted uranium deposits, South China, 2000, Min M. Z. , Meng Z. W. , Sheng G. Y. , Min Y. S. , Liu X. ,
The paleokarst-hosted uranium deposits in organic-matter, clay-rich Devonian-Carboniferous carbonates are an economically important, new type of uranium deposit in China. The organic matter intimately associated with the uranium mineralization in this type of deposit has been characterized by petrographic, isotopic, gas chromatographic, pyrolysis-gas chromatographic, infrared spectroscopic and elemental geochemical methods. Comparing genetic types of the organic matter in unmineralized and mineralized samples indicates that no fundamental differences are found. The organic matter is chiefly of marine origin and contains a minor terrestrial component. The immature nature of the indigenous organic matter in the unmineralized samples shows generally a low-temperature history (less than or equal to max. 65 degrees C), and geologic data show a shallow maximal burial depth. By combining the organic geochemistry with the geological data, U-Pb dating and temperature determinations, an overall formation process for this type of uranium deposit is deduced. The formation of the paleokarst-hosted uranium deposits in South China is the result of: (1) repeated paleokarstifications of the Devonian and Carboniferous organic, clay-rich carbonate along the faults and unconformities between different strata because of the Hercynian and Yanshanian regional tectonism, and extensive formation of solution-collapse, solution-fault breccias; (2) accumulation of organic matter and clays in the paleocaverns and matrix of the breccias, fixation and adsorption of uranium by the organic matter and clays from the paleokarst waterflows that leached metals from the uranium-bearing host carbonates during their passage towards the karst zones, (3) reduction of uranium by the organic matter and formation of protore and low-grade ore; (4) circulation of heated formational waters and deep circulating, uraniferous meteoric waters by tectonic pumping, reworking the uranium-rich, paleocave-fillings, protore and low-grade ore, reduction and formation of primary uranium minerals (uraninite and coffinite) because of the reducing environment resulting from organic matter and sulfide. (C) 2000 Elsevier Science B.V. Ail rights reserved

The Salt That Wasn't There: Mudflat Facies Equivalents to Halite of the Permian Rustler Formation, Southeastern New Mexico, 2000, Powers Dennis W. , Holt Robert M. ,
Four halite beds of the Permian Rustler Formation in southeastern New Mexico thin dramatically over short lateral distances to correlative clastic (mudstone) beds. The mudstones have long been considered residues after post-burial dissolution (subrosion) of halite, assumed to have been deposited continuously across the area. Hydraulic properties of the Culebra Dolomite Member have often been related to Rustler subrosion. In cores and three shafts at the Waste Isolation Pilot Plant (WIPP), however, these mudstones display flat bedding, graded bedding, cross-bedding, erosional contacts, and channels filled with intraformational conglomerates. Cutans indicate early stages of soil development during subaerial exposure. Smeared intraclasts developed locally as halite was removed syndepositionally during subaerial exposure. We interpret these beds as facies formed in salt-pan or hypersaline-lagoon, transitional, and mudflat environments. Halite is distributed approximately as it was deposited. Breccia in limited areas along one halite margin indicates post-burial dissolution, and these breccias are key to identifying areas of subrosion. A depositional model accounts for observed sedimentary features of Rustler mudstones. Marked facies and thickness changes are consistent with influence by subsidence boundaries, as found in some modern continental evaporites. A subrosion model accounts for limited brecciated zones along (depositional) halite margins, but bedding observed in the mudstones would not survive 90% reduction in rock volume. Depositional margins for these halite beds will be useful in reconstructing detailed subsidence history of the Late Permian in the northern Delaware Basin. It also no longer is tenable to attribute large variations in Culebra transmissivity to Rustler subrosion

Diagenetic History of Pipe Creek Jr. Reef, Silurian, North-Central Indiana, U.S.A, 2000, Simo J. A. , Lehmann Patrick J. ,
Calcite cements in the Silurian (Ludlovian) Pipe Creek Jr. Reef, north-central Indiana, are compositionally zoned with characteristic minor-element concentrations and stable-isotope signatures, and were precipitated in different diagenetic environments. Superposition and crosscutting relationships allow us to group cement zones and to relate them to the sequence stratigraphic evolution of the reef. Pipe Creek Jr. Reef grew in normal marine waters, with the reef top high (greater than 50 m) above the platform floor. Flank facies are volumetrically important and are preserved largely as limestone, in contrast to most dolomitized Silurian reefs in the midcontinent. Syndepositional marine cements fill primary porosity and synsedimentary fractures and are interlayered with marine internal sediment. Now low-magnesium calcite, their isotopic compositions are similar to those of depositional grains and cements estimated to have precipitated from Ludlovian sea waters. Depositional porosity was reduced by 75% by the precipitation of these syndepositional cements, which stabilized the steeply dipping flank slope. Postdepositional, clear calcite cements are interpreted as shallow-phreatic and burial cements on the basis of their relationship to periods of karstification and fracturing. Shallow-phreatic cements, with concentric cathodoluminescent (CL) zonation, precipitated in primary pores and are postdated by fractures and caves filled with Middle Devonian sandstone. CL zonal boundaries are sharp, and some, near a major stratigraphic unconformity, show evidence of dissolution. The volumetric abundance of the individual CL zones varies in the reef, indicating a complex superposition of waters of varying chemistry and rock-water interaction that are probably related to relative sea-level changes. This important aspect of the reef stratigraphy is recorded only by the diagenetic succession, because evidence of earlier sea-level changes is removed by a major later regional unconformity. Burial cements are the youngest diagenetic feature recognized, and they rest conformably or unconformably over older cements. They exhibit both concentric CL zonation and sectoral zoning, they are ferroan to nonferroan, and they contain thin sulfide zones along growth-band boundaries. Their isotopic compositions do not overlap with shallow-phreatic or marine cement values. Degraded oil postdates burial cements, and is composed of the same sterane class as the Devonian-age Antrim Shale, the probable source rock. This source contrasts with that of reef reservoirs in the Michigan Basin, where Silurian strata are commonly the hydrocarbon source

Dolomitization and Dolomite Neomorphism: Trenton and Black River Limestones (Middle Ordovician) Northern Indiana, U.S.A, 2000, Yoo Chan Min, Gregg Jay M. , Shelton Kevin L. ,
The Trenton and Black River Limestones are dolomitized extensively along the axis of the Kankakee Arch in Indiana, with the proportion of dolomite decreasing to the south and southeast of the arch. Planar and nonplanar dolomite replacement textures and rhombic (type 1) and saddle (type 2) void-filling dolomite cements are present. Three stages of dolomitization, involving different fluids, are inferred on the basis of petrographic and geochemical characteristics of the dolomites. Nonferroan planar dolomite has relatively high {delta}18O values (-1.8 to -6.1{per thousand} PDB) and has 87Sr/86Sr ratios (0.70833 to 0.70856) that overlap those of Middle Ordovician seawater. Petrography, geochemistry, and the geometry of the dolomitized body suggest that the planar dolomite was formed in Middle and Late Ordovician seawater during the deposition of the overlying Maquoketa Shale. Ferroan planar and nonplanar dolomite occurs in the upper few meters of the Trenton Limestone, confined to areas underlain by planar dolomite. This dolomite contains patches of nonferroan dolomite with cathodoluminescence (CL) characteristics similar to underlying planar dolomite. Ferroan dolomite has relatively low {delta}18O values (-5.1 to -7.3{per thousand} PDB) and has slightly radiogenic 87Sr/86Sr ratios (0.70915 to 0.70969) similar to those obtained for the overlying Maquoketa Shale. These data indicate that ferroan dolomite formed by neomorphism of nonferroan planar dolomite as fluids were expelled from the overlying Maquoketa Shale during burial. The absence of ferroan dolomite at the Trenton-Maquoketa contact, in areas where the earlier-formed nonferroan planar dolomite also is absent, indicates that the fluid expelled from the overlying shale did not contain enough Mg2 to dolomitize limestone. Type 1 dolomite cement has isotopic compositions similar to those of the ferroan dolomite, suggesting that it also formed from shale-derived burial fluids. CL growth zoning patterns in these cements suggest that diagenetic fluids moved stratigraphically downward and toward the southeast along the axis of the Kankakee Arch. Type 2 saddle dolomite cements precipitated late; their low {delta}18O values (-6.0 to -7.0{per thousand} PDB) are similar to those of the type 1 dolomite cement. However, fluid-inclusion data indicate that the saddle dolomite was precipitated from more saline, basinal fluids and at higher temperatures (94{degrees} to 143{degrees}C) than the type 1 cements (80{degrees} to 104{degrees}C). A trend of decreasing fluid-inclusion homogenization temperatures and salinities from the Michigan Basin to the axis of Kankakee Arch suggests that these fluids emerged from the Michigan Basin after precipitation of type 1 cement

Nang Nuan oil field, B6/27, Gulf of Thailand: karst reservoirs of meteoric or deep-burial origin?, 2000, Heward A. P. , Chuenbunchom S. , Makel G. , Marsland D. , Spring L. ,
Karst reservoirs in the Chumphon Basin of the Gulf of Thailand have produced oil at well rates exceeding 10 000 BBL/d. Meteorically karstified buried hills were recognized as a potential exploration play. The Nang Nuan discovery well appeared to confirm such a play, and the concept prevailed despite the accumulation of contrary and unusual data. By the time a subsequent well had produced nearly 4 x 10(6) BBL oil, there was a desire to better understand the prospectivity of the concession. The accumulated data indicate that the highs are probably syn-rift horsts and inversion features. Karst reservoirs occur in Ratburi carbonates, and Mesozoic and Tertiary clastics, apparently unrelated to subaerial exposure. The karstification appears to be primarily of deep-burial origin, as indicated by the nature of the karst, substantial pore volumes that are difficult to account for, and temperature and flow anomalies consistent with active geothermal circulation. There are granites and hot springs in the vicinity, and abundant CO2 in this and neighbouring basins. Such deep-burial karst reservoirs have different implications for reserves estimation, prospect ranking and well completions

Locating dissolution features in the Chalk, 2000, Matthews M. C. , Clayton C. R. I. , Rigbyjones J. ,
Dissolution features are common in the Chalk and may result in differential or collapse settlement of foundations if undetected. Dissolution pipes and cavities may be easily missed by conventional drilling methods. Probing and geophysical methods of investigation offer an attractive alternative due to their ability to cover large areas rapidly and thus minimize cost. The success of geophysical methods depends on many factors, principally the size of the feature in relation to the depth of burial and the cover material. This paper describes a study of dynamic probing and a number of geophysical methods used to locate dissolution features at two sites with contrasting ground conditions. The first site contained a bowl-shaped doline over a clay-filled dissolution pipe beneath a relatively thin soil cover. At the second site there was a thick, predominantly granular cover material that contained cavities which had migrated from dissolution pipes in the chalk below. Ground truth data from trenching was obtained to provide a basis for evaluating the investigation methods used. The ability of both dynamic probing and geophysical methods to locate and map dissolution features is discussed

Formation of dolomite mottling in Middle Triassic ramp carbonates (Southern Hungary), 2000, Torok A. ,
The Middle Triassic carbonates of the Villany Mountains were deposited on a homoclinal carbonate ramp. Many of the carbonates from the 700 m-thick sequence show partial or complete dolomitization. The present paper describes dolomites that occur in a limestone unit as irregular mottles and as pore- and fracture-filling cements. Replacement-type scattered dolomite rhombs in the mottles having inclusion-rich, very dull luminescent cores and limpid non-luminescent outer zones represent the initial phase of dolomitization. The isotopic composition of these dolomites (delta(13)C = .30 parts per thousand VPDB, delta(18)O = -3.60 parts per thousand VPDB) is similar to that of the calcitic micrite (delta(13)C = .6 parts per thousand VPDB, delta(18)O = -4.00 parts per thousand VPDB) indicating that no external fluids were introduced during dolomite formation. The elevated Sr content of the micrites implies that sediment was originally aragonite or high-Mg calcite. Dolomitization took place in the burial realm from a 'marine' pore-fluid in a partly closed system. Later fracture-related saddle dolomite reflects elevated formation temperatures and increasing burial. Five calcites were identified. Multiple generations of calcite-filled fractures were formed during burial diagenesis generally having dull or no luminescence (delta(13)C = .80 parts per thousand VPDB, delta(18)O = -6.40 parts per thousand VPDB). The latest phase calcites are related to karst formation, having a very negative isotopic composition (delta(13)C = -5.0 to -7.2 parts per thousand VPDB and delta(18)O approximate to -7.44 parts per thousand VPDB). The karst-related processes include dissolution, calcite precipitation and partial replacement of dolomites by complex zoned bright yellow calcite. The timing of dolomitization is uncertain, but the first phase took place in a partly closed system prior to stylolite formation. Late-stage saddle dolomites were precipitated during maximum burial in the Cretaceous. The dissolution of dolomites and karst-related calcite replacement was not earlier than Late Cretaceous. (C) 2000 Elsevier Science B.V. All rights reserved

Speleogenesis in gypsum, 2000, Klimchouk A.
The main differences between the solutional properties of gypsum and those of calcite lie in the much higher solubility of gypsum, and in dissolution kinetics of gypsum which is solely diffusion controlled. Unlike calcite, no change of kinetic order occurs with an increase in concentration. Initiation of long lateral flow paths through gypsum is virtually impossible due to the rapid rate of dissolution; no kinetic mechanisms allow slow but uniform dissolutional enlargement throughout the flow paths. Near the surface, fissures are already wide enough for cave development to occur, which is extremely competitive due to rapid dissolution kinetics and the strong dependence of enlargement rates on flow velocity and discharge. Thus caves in gypsum in exposed settings are mainly linear or crudely branching, rapidly adjusting to the contemporary geomorphic setting and available recharge. Vertical pipes or pits form in the vadose zone. No deep phreatic development and no artesian development by lateral flow from distant recharge areas can occur. However, cave origin and development does occur in deep-seated confined settings where gypsum beds in stratified sequences are underlain by, or sandwiched between poorly soluble aquifers. Two situations support cave origin in gypsum in deep-seated settings: (1) transverse flow through gypsum between overlying and underlying aquifers, and (2) lateral flow in an insoluble but permeable aquifer underlying a gypsum bed. The former situation generates either maze caves where uniformly distributed fissure networks exist in the gypsum, or discrete voids where the otherwise low-fissured gypsum is disrupted by prominent tectonic fractures. If considerable conduit porosity has been created in a deep-seated setting, it provides ready paths for more intense groundwater circulation and further cave development when the gypsum is uplifted into the shallow subsurface. Thick and low-fissured sulfate strata can survive burial with no speleogenesis at all where surrounded by poorly permeable beds. When exposed to the surface, such gypsum deposits undergo speleogenetic development with no inherited features, presenting the pure line of open karst.

Lithological and structural controls of cave development, 2000, Klimchouk A. , Ford D.
This Chapter summarizes the important general controls that lithology and geologic structure impose on most cave genesis: rock purity, the presence of interbedded clastic rocks and adjacent or interbedded sequences of sulfates and carbonates, and various kinds of initial porosity, fissures in particular. Lithological and structural conditions for speleogenesis evolve throughout sedimentation, eogenesis, mesogenesis and telogenesis and change drastically between these stages. Inheritance in the evolution of different kinds of pre-speleogenetic porosity causes increasing heterogeneity in their distribution and parameters, which reaches the highest degree at the stage of rock emergence to the shallow subsurface and the surface after burial. The importance of fabric-selective porosity and stratigraphical elements diminishes with time in favor of fissure network porosity. Fissures evolve at different stages of the rock evolution. Networks are composed of complex planar and curvilinear surfaces interconnecting in three dimensions, constructed from fissures of various origins, generations and ages. The initial structural conditions for speleogenesis thus can be very varied depending on which particular stage speleogenesis commences. Conditions in deep-seated settings favor uniform speleogenetic development, while in shallow settings increased heterogeneity in fissure parameters can favor selective development. Modeling of conduit initiation and early development needs to take into account a great variability of initial permeability structures between common geological environments and evolutionary stages, especially rather dynamic non-dissolutional changes of these structures in shallow settings.

Types of karst and evolution of hydrogeologic settings, 2000, Klimchouk A. , Ford D.
Karst is treated as a specific kind of fluid circulation system capable to self-development and self-organization. Active karst may evolve at wide range of geological environments, from deep-seated (without any apparent relation to the surface) to sub-surface, and be represented by confined and unconfined circulation systems. Extrinsic factors and intrinsic mechanisms of karst development change regularly and considerably within the general cycle of geological evolution of a soluble rocks or, more specifically, within hydrogeologic cycle. The latter encompasses a period of exposure between major transgressions and is characterized by progressively expanding meteoric groundwater circulation. A broad evolutionary approach is therefore needed to differentiate between karst types, which concurrently represent distinct stages of karst development. This is also a mean to adequately classify speleogenetic settings. Evolutionary typology of karst considers the whole cycle of a formation's life, from deposition (syngenetic karst) through deep burial to exposure and denudation. The group of intrastratal karst types includes deep-seated, subjacent, entrenched and denuded karst, the latter also fall into the group of exposed karst types. Exposed karst includes also open karst which represents the pure line of exposed development, that is karst evolved solely when the soluble rock has been exposed to the surface. Exposed karst development can be interrupted by a subsequent burial (buried karst), with paleokarst formed in result, and rejuvenated by exhumation. The types of karst are marked by characteristic associations of structural prerequisites for groundwater flow and speleogenesis, flow regime, recharge mode and recharge/discharge configurations, groundwater chemistry and a degree of inheritance. Consequently, these associations generate particular types of caves.

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.

Diagenesis and porosity evolution of the Upper Silurian-lowermost Devonian West Point reef limestone, eastern Gaspe Belt, Quebec Appalachians, 2001, Bourque Pa, Savard Mm, Chi G, Dansereau P,
Diagenetic analysis based on cathodoluminescence petrography, cement stratigraphy, carbon and oxygen stable isotope geochemistry, and fluid inclusion microthermometry was used to reconstruct the porosity history and evaluate the reservoir potential of the Upper Silurian-Lower Devonian West Point limestone in the eastern part of the Gaspe Belt. The West Point limestone was investigated in two areas: 1) In the Chaleurs Bay Synclinorium, the limestone diagenesis of the lower and middle complexes of the Silurian West Point Formation was affected by repeated subaerial exposure related to late Ludlovian third-order eustatic low-stands, which coincided with the Salinic block tilting that produced the Salinic unconformity. The Anse McInnis Member (middle bank complex) underwent freshwater dissolution, and mixed marine and freshwater cementation during deposition. Concurrently, the underlying Anse a la Barbe and Gros Morbe members (lower mound and reef complex) experienced dissolution by fresh water percolating throughout the limestone succession. Despite this early development of karst porosity, subsequent meteoric-influenced cementation rapidly occluded all remaining pore space in the Gros Morbe, Anse a la Barbe, and Anse McInnis limestones. In contrast, the overlying Colline Daniel Member limestone (upper reef complex) does not show the influence of any freshwater diagenesis. Occlusion of its primary porosity occurred during progressive burial and was completed under a maximum burial depth of 1.2 kin. 2) In the Northern Outcrop Belt, the diagenesis of the Devonian pinnacle reefs of the West Point Formation followed a progressive burial trend. The primary pores of the reef limestone were not completely occluded before the reefs were buried at a significant depth (in some cases, to 6 km). Therefore, hydrocarbon migration in subsurface buildups before primary porosity occlusion might have created reservoirs. Moreover, the presence of gaseous hydrocarbons in Acadian-related veins attests to a hydrocarbon source in the area

Results 31 to 45 of 103
You probably didn't submit anything to search for