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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

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That doline karst is karst dominated by closed depressions, chiefly dolines, perforating a simple surface [25].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Paleokarst - a Systematic and Regional Review, 1989,

Description
Prepared by some of the world's leading experts in the field, this book is the first summarizing work on the origin, importance and exploitation of paleokarst. It offers an extensive regional survey, mainly concerning the Northern Hemisphere, as well as a thorough analysis of the problems of research into paleokarst phenomena, with particular emphasis on theoretical contributions and practical exploitation. By concentrating on phenomena which have appeared in the course of geological history, the book represents a substantial development in the general theory of paleokarst and demonstrates the advantages of a comprehensive approach to the problem. Considerable emphasis is put on the economic importance of paleokarst phenomena, from the point of view of exploiting significant deposits of mineral raw materials, as well as from a civil engineering and hydrological point of view. Since the publication deals with a boundary scientific discipline, it is intended for specialists from various branches of science: geologists, paleontologists, economic geologists, geographers, mining engineers and hydrogeologists.

Contents
List of Contributors. Foreword.

Part I. Introduction.
Introduction (P. Bosák et al.). Paleokarst as a problem (J. Głazek, P. Bosák, D.C. Ford). Terminology (P. Bosák, D.C. Ford, J. Głazek).

Part II. Regional Review.
Paleokarst of Belgium (Y. Quinif). Paleokarst of Britain (T.D. Ford). Paleokarst of Norway (S.-E. Lauritzen). Paleokarst of Poland (J. Głazek). Paleokarst of Czechoslovakia (P. Bosák, I. Horáček, V. Panoš). Paleokarst of Hungary (G. Bárdossy, L. Kordos). Hydrothermal paleokarst of Hungary (P. Müller). Paleokarst of Italy. Selected examples from Cambrian to Miocene (M. Boni, B. D'Argenio). Paleokarst-related ore deposits of the Maghreb, North Africa (Y. Fuchs, B. Touahri). Paleokarst of Yugoslavia (D. Gavrilović). Paleokarst of Bulgaria (I. Stanev, S. Trashliev). Paleokarst of Romania (M. Bleahu). Paleokarst of the Union of Soviet Socialist Republics (R.A. Tsykin). Paleokarst of China (Zhang Shouyue). Paleokarst of Canada (D.C. Ford). Paleokarst of the United States (M.V. Palmer, A.N. Palmer).

Part III. Mineral Deposits Connected With Karst.
An introduction to karst-related mineral deposits (P. Bosák). Pb-Zn ores (S. Dżułyński, M. Sass-Gustkiewicz). Bauxites (G. Bárdossy). Iron ore deposits in paleokarst (G. Bárdossy, Y. Fuchs, J. Głazek). Clays and sands in paleokarst (P. Bosák). The oceanic karst: modern bauxite and phosphate ore deposits on the high carbonate islands (so-called ``Uplifted Atolls'') of the Pacific Ocean (F.G. Bourrouilh-le Jan). Paleokarst-related uranium deposits (Y. Fuchs).

Part IV. Hydrogeology and Engineering Hazards in Paleokarst Areas.
Paleokarst as an important hydrogeological factor (J. Zötl). Hydrogeological problems of opencast and underground mining of mineral deposits encountered during their exploration, development and exploitation stages (P. Bosák). Hydrogeological problems of the Cracow-Silesia Zn-Pb ore deposits (Z. Wilk). Hydrogeological problems of Hungarian bauxite and coal deposits (T. Böcker, B. Vizy). Paleokarst in civil engineering (A. Eraso). Interaction between engineering and environment in the presence of paleokarst: some case histories (J. Głazek).

Part V. Paleokarst as a Scientific Subject.
Special characteristics of paleokarst studies (I. Horáček, P. Bosák). Tectonic conditions for karst origin and preservation (J. Głazek). Problems of the origin and fossilization of karst forms (P. Bosák). Biostratigraphic investigations in paleokarst (I. Horáček, L. Kordos).

Part VI. Conclusions. Part VII. References. Part VIII. Indexes.
Author Index. Geographical Index. Subject Index.

Bibliographic & ordering Information
Hardbound, ISBN: 0-444-98874-2, 726 pages, publication date: 1989
Imprint: ELSEVIER


Drainage Evolution in a Tasmanian Glaciokarst, 1989, Kiernan, Kevin

The intensively glaciated mountains of the Picton Range - Mt. Bobs area in southwestern Tasmania contain prominent karst features that have been developed in carbonate formations of Devonian, Ordovician and possibly Precambrian age. This paper reviews the extent of the karst and glacial features and records the tracing of the underground drainage from the alpine Lake Sydney. Glacial erosion has exposed areas of limestone to karstification and glacial diversion of drainage has played a critical role in the evolution of the present underground drainage patterns. Prior to the late Last Glacial Stage the deflection of marginal meltwaters from the former Farmhouse Creek Glacier against the Burgess - Bobs Saddle led to the development of an underground breach of a major surface drainage divide. Subglacial or submarginal meltwaters associated with a much smaller glacier that developed in the same valley during the late Last Glacial Stage probably played a significant role in the breaching of a minor divide within the Farmhouse Creek catchment. This led to the development of an underground anabranch of Farmhouse Creek that by-passes the glacial Pine Lake. However, it is possible that the latter diversion is entirely Holocene in age and is related to postglacial dilation of the limestone rather than meltwater flows.


ORIGIN AND MORPHOLOGY OF LIMESTONE CAVES, 1991, Palmer A. N. ,
Limestone caves form along ground-water paths of greatest discharge and solutional aggressiveness. Flow routes that acquire increasing discharge accelerate in growth, while others languish with negligible growth. As discharge increases, a maximum rate of wall retreat is approached, typically about 0.01-0.1 cm/yr, determined by chemical kinetics but nearly unaffected by further increase in discharge. The time required to reach the maximum rate is nearly independent of kinetics and varies directly with flow distance and temperature and inversely with initial fracture width, discharge, gradient, and P(CO2). Most caves require 10(4) - 10(5) yr to reach traversable size. Their patterns depend on the mode of ground-water recharge. Sinkhole recharge forms branching caves with tributaries that join downstream as higher-order passages. Maze caves form where (1) steep gradients and great undersaturation allow many alternate paths to enlarge at similar rates or (2) discharge or renewal of undersaturation is uniform along many alternate routes. Flood water can form angular networks in fractured rock, anastomotic mazes along low-angle partings, or spongework where intergranular pores are dominant. Diffuse recharge also forms networks and spongework, often aided by mixing of chemically different waters. Ramiform caves, with sequential outward branches, are formed mainly by rising thermal or H2S-rich water. Dissolution rates in cooling water increase with discharge, CO2 content, temperature, and thermal gradient, but only at thermal gradients of more than 0.01-degrees-C/m can normal ground-water CO2 form caves without the aid of hypogenic acids or mixing. Artesian flow has no inherent tendency to form maze caves. Geologic structure and stratigraphy influence cave orientation and extent, but alone they do not determine branch-work versus maze character

RECOGNITION OF MICROCLIMATE ZONES THROUGH RADON MAPPING, LECHUGUILLA CAVE, CARLSBAD-CAVERNS-NATIONAL-PARK, NEW-MEXICO, 1991, Cunningham Ki, Larock Ej,
Radon concentrations range from < 185 to 3,515 Bq m-3 throughout Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico. Concentrations in the entrance passages and areas immediately adjacent to these passages are controlled by outside air temperature and barometric pressure, similar to other Type 2 caves. Most of the cave is developed in three geographic branches beneath the entrance passages; these areas maintain Rn levels independent of surface effects, an indication that Rn levels in deep, complex caves or mines cannot be simply estimated by outside atmospheric parameters. These deeper, more isolated areas are subject to convective ventilation driven by temperature differences along the 477-m vertical extent of the cave. Radon concentrations are used to delineate six microclimate zones (air circulation cells) throughout the cave in conjunction with observed airflow data. Suspected surface connections contribute fresh air to remote cave areas demonstrated by anomalous Rn lows surrounded by higher values, the presence of mammalian skeletal remains, CO2 concentrations and temperatures lower than the cave mean, and associated surficial karst features

Le massif du Seuil : organisation des rseaux souterrains (Chartreuse, France), 1994, Loiseleur, B.
The Seuil massif (?13 km2) is located east of the Chartreuse massif North and south of the massif some of the most important cave systems in France are to be found. The two main underground systems of the Seuil which are not connected, are the Mort R cave (? 7 km long) and the Guiers-Vif system ( 15 kin long) connected with the trou des Flammes. Over the last few years, the knowledge of these systems has increased signifi-cantly and some junctions have been made with the plateau (Masques - Mort Ru; Tasurinchi -Guiers-Vif; Trou des Flammes Guiers-Vif). But the Malissard river, the main branch of the Guiers-Vif, is located under the Lances de Malissard, on the western end of the massif This location can be explai-ned by the typical order of the synclinal axis. The local cavers hope to find a system, comparable to that of Dent de Crolles and Alpe. The main collector seems to be in the axis of the massif along the GR9 fault. A comparison between the Chartreuse systems therefore shows that there seems to be reasonable hope in the years to come.

BACTERIA, FUNGI AND BIOKARST IN LECHUGUILLA CAVE, CARLSBAD-CAVERNS-NATIONAL-PARK, NEW-MEXICO, 1995, Cunningham Ki, Northup De, Pollastro Rm, Wright Wg, Larock Ej,
Lechuguilla Cave is a deep, extensive, gypsum- and sulfur-bearing hypogenic cave in Carlsbad Caverns National Park, New Mexico, most of which (> 90%) lies more than 300 m beneath the entrance. Located in the arid Guadalupe Mountains, Lechuguilla's remarkable state of preservation is partially due to the locally continuous Yates Formation siltstone that has effectively diverted most vadose water away from the cave. Allocthonous organic input to the cave is therefore very limited, but bacterial and fungal colonization is relatively extensive: (1) Aspergillus sp. fungi and unidentified bacteria are associated with iron-, manganese-, and sulfur-rich encrustations on calcitic folia near the suspected water table 466 m below the entrance; (2) 92 species of fungi in 19 genera have been identified throughout the cave in oligotrophic (nutrient-poor) ''soils'' and pools; (3) cave-air condensate contains unidentified microbes; (4) indigenous chemoheterotrophic Seliberius and Caulobacter bacteria are known from remote pool sites; and (5) at least four genera of heterotrophic bacteria with population densities near 5 x 10(5) colony-forming units (CFU) per gram are present in ceiling-bound deposits of supposedly abiogenic condensation-corrosion residues. Various lines of evidence suggest that autotrophic bacteria are present in the ceiling-bound residues and could act as primary producers in a unique subterranean microbial food chain. The suspected autotrophic bacteria are probably chemolithoautotrophic (CLA), utilizing trace iron, manganese, or sulfur in the limestone and dolomitic bedrock to mechanically (and possibly biochemically) erode the substrate to produce residual floor deposits. Because other major sources of organic matter have not been detected, we suggest that these CLA bacteria are providing requisite organic matter to the known heterotrophic bacteria and fungi in the residues. The cavewide bacterial and fungal distribution, the large volumes of corrosion residues, and the presence of ancient bacterial filaments in unusual calcite speleothems (biothems) attest to the apparent longevity of microbial occupation in this cave

EARLY DEVELOPMENT OF KARST SYSTEMS .2. TURBULENT-FLOW, 1995, Howard A. D. , Groves C. G. ,
A simulation model developed to explore patterns of fracture enlargement within incipient limestone karst aquifers has been extended to turbulent flow. In contrast to the highly selective passage enlargement that occurs early in cave network development under laminar flow, the transition to turbulent flow results in more general passage enlargement, leading to maze networks when initial fractures are large and hydraulic gradients are high. These results support previously published hypotheses for the development of maze patterns, including formation within structural settings that have created initially large fractures or within flow systems periodically inundated by flooding. Maze development is also favored under turbulent flow when passages are entirely water filled, and where the groundwater flow system is long-lived. By contrast, branched patterns are most common when passages become free-surface subterranean streams, because depression of the piezometric surface along main passages, downcutting along main passages, and possible infilling with sediment of side passages limit the sharing of discharge among interconnected fractures or bedding planes that promote maze development

Controls on the evolution of the Namurian paralic basin, Bohemian Massif, Czech Republic, 1997, Kumpera O. ,
The Namurian A paralic molasse deposits of the Upper Silesian Coal Basin form erosion remnants of an extensive foreland basin located in the eastern part of the Bohemian Massif. This basin represents the latest stage of development of the Moravian-Silesian Paleozoic Basin (Devonian-Westphalian). The paralic molasse stage of the foreland basin evolved from foreland basins with flysch and with marine molasse. The deposition of the thick paralic molasse (Ostrava Formation) started in the Namurian A. In comparison with other coal-bearing foreland basins situated along the Variscan margin in Europe, this is characterized not only by earlier deposition, but also by a different tectonic setting. It is located in the Moravian-Silesian branch of the Variscan orocline striking NNE-SSW, i.e. perpendicularly to the strikes of more western European foreland basins. In the Visean and Namurian, the foreland basin developed rapidly under the influence of the western thrustfold belt in the collision zone. The deposition was influenced by contrasting subsidence activities of the youngest and most external trough -- Variscan foredeep -- and the platform. The Upper Silesian Basin shows therefore a distinct W-E lithological and structural polarity and zonation

Hydrological response of small watersheds following the Southern California Painted Cave Fire of June 1990, 1997, Keller E. A. , Valentine D. W. , Gibbs D. R. ,
Following the Painted Cave Fire of 25 June 1990 in Santa Barbara, California which burned 1214 ha, an emergency watershed protection plan was implemented consisting of stream clearing, grade stabilizers and construction of debris basins. Research was initiated focusing on hydrological response and channel morphology changes on two branches of Maria Ygnacio Creek, the main drainage of the burned area. Research results support the hypothesis that the response of small drainage basins in chaparral ecosystems to wildfire is complex and flushing of sediment by fluvial processes is more likely than by high magnitude debris flows. During the winter of 1990-1991, 35-66 cm of rainfall and intensities up to 10 cm per hour for a five-minute period were recorded with a seasonal total of 100% of average (normal) rainfall (average = 63 cm/year). During the winter of 1991-1992, 48-74 cm of rainfall and intensities up to 8 cm per hour were recorded with a seasonal total of 115% of normal. Even though there was moderate rainfall on barren, saturated soils, no major debris flows occurred in burned areas. The winter of 1992-1993 recorded total precipitation of about 170% of normal, annual average intensities were relatively low and again no debris flows were observed. The response to winter storms in the first three years following the fire was a moderate but spectacular flushing of sediment, most of which was derived from the hillslopes upstream of the debris basins. The first significant storm and stream flow of the 1990-1991 winter was transport-limited resulting in large volumes of sediment being deposited in the channel of Maria Ygnacio Creek; the second storm and stream flow was sediment-limited and the channel scoured. Debris basins trapped about 23 000 m(3), the majority coming from the storm of 17-20 March 1991. Sediment transported downstream during the three winters following the fire and not trapped in the debris basins was eventually flushed to the estuarine reaches of the creeks below the burn area, where approximately 108 000 m(3) accumulated. Changes in stream morphology following the fire were dramatic as pools filled with sediment which greatly smoothed longitudinal and cross-sectional profiles. Major changes in channel morphology occur following a fire as sediment derived from the hillslope is temporarily stored in channels within the burned area. However, this sediment may quickly move downstream of the burned region, where it may accumulate reducing channel capacity and increasing the flood hazard. Ecological consequences of wildfire to the riparian zone of streams in the chaparral environment are virtually unknown, but must be significant as the majority of sediment (particularly gravel necessary for fish and other aquatic organisms) entering the system does so in response to fires. (C) 1997 by John Wiley & Sons, Ltd

Did the Argonauts of Greek myth go underground in the Slovene karst?, 1998, Shaw Trevor R. , Macqueen James G.

Lazius's maps of Carniola, the first of which was printed in 1545, have a note at Vrhnika, where the Ljubljanica rises from its subterranean course, saying that the Argonauts of the Greek golden fleece myth went underground there on their way from the Black Sea to the Adriatic. The original Greek sources describe only a surface route, either following a branch of the Sava running west to the sea, or requiring their ship to be carried overland for this part of the journey. Elsewhere, though, it was said that fish pass from one sea to the other by underground channels. The subterranean variant of the Argonaut story has not been traced before Lazius, though he may have got the idea from another mapmaker, Hirschvogel, who had lived in Ljubljana. Münster's map of 1550 implies the existence of an underground river between Vrhnika and the Mirna river in Istria, but it does not associate it with the Argonaut story. The idea seems to have arisen just when maps were showing that hills formed a barrier between the east-flowing Sava and the rivers of the Adriatic basin, and when the existence of caves and underground rivers was becoming more widely known.


Influence of modern farming on karstic landscapes , 1998, Rejec Brancelj, Irena

This article is focused upon the present characteristics of farming in karstic landscapes Bela krajina, Dobrepolje and the Valley of Ribnica with Kočevje, mainly from the point of view of environment pollution. In all of them limestone with underground drainage prevails. Regarding its characteristics, we cannot define farming in the discussed karstic regions as extensive. The most important agricultural branch is cattle-breeding. All the data used for the estimation of the ecological influences of farming were collected through proper field work by making inquiries. Cultivated land was being fertilised mostly with stable manure and mineral fertilisers. The ecological awareness of farmers is actually at its starting point, and in all these delicate karstic regions it can be defined as definitely too low.


Sinkholes in karst mining areas in China and some methods of prevention, 1999, Li G. Y. , Zhou W. F. ,
Mining of coal, lead and zinc, gold, and iron ore deposits in karst areas has been closely associated with sinkholes in China. Surface collapse causes an increase in mine water drainage and the possibility of major water inflow from karst aquifers, which threatens the environment in mining areas and endangers the mine safety. A combination of factors including soil weight, buoyancy, suffusion process and vacuum suction can contribute to the sinkhole formation. The key measures to prevent sinkholes in mining areas are to control the amount of mine drainage, reduce water level fluctuation, seal-off karst conduits and subsurface cavities in the overlying soil, prevent water inflow, and/or to increase gas pressure in the karst conduits. (C) 1999 Elsevier Science B.V. All rights reserved

Karst aquifer evolution in fractured rocks, 1999, Kaufmann G. , Braun J. ,
We study the large-scale evolution and flow in a fractured karst aquifer by means of a newly developed numerical method. A karst aquifer is discretized into a set of irregularly spaced nodal points, which are connected to their set of natural neighbors to simulate a network of interconnected conduits in two dimensions. The conduits are allowed to enlarge by solutional widening. The geometric flexibility of this method, along with a simplified model for the dissolution kinetics within the system water-carbon dioxide-calcite, enables us to study both laminar and turbulent flow in a karst aquifer during its early phase of evolution. A sensitivity analysis is conducted for parameters such as conduit diameter, hydraulic pressure differences, and recharge conditions along the surface of the aquifer and shows that passage evolution depends strongly on the recharge condition and the amount of water available. Under fixed hydraulic head boundary conditions an early single-passage system develops under laminar conditions and is transformed into a maze-like passage system after the onset of turbulence. Fixed recharge boundary conditions are more likely to result in a branchwork-like passage system, although the addition of distributed recharge may lead to a maze-like system of secondary passages

The initiation of hypogene caves in fractured limestone by rising thermal water: investigation of a parallel series of competing fractures, 1999, Dumont K. A. , Rajaram H. , Budd D. A.
Integrated cave systems can either form at or near the surface of the earth (epigenic) or at some depth below the earth's surface (hypogenic)For caves that form in fractured limestone, the two most common types of cave-system morphologies are branchwork and mazeworkBranchwork caves are composed of tributaries that coalesce in the downstream direction, similar to surface streamsMazework caves exhibit two or more sets of parallel passages intersecting in a grid-like patternThe majority of epigenic caves exhibit branchwork morphologies, which represent the dominance of individual flow pathsIn contrast, mazework caves develop when dissolution occurs along numerous flow pathsWhereas most epigenic caves are related to surficial meteoric flow systems, some mazework caves are thought to have formed in hypogene environments where rising thermal water cools in response to the geothermal gradientOur objective is to examine the fundamental cause for the difference in morphology between epigenic and thermal hypogenic cave systems using numerical modelsIn particular, we are examining the competition between different flow paths in fractured limestone undergoing dissolutional enlargementAs noted in previous numerical studies, epigenic systems are characterized by the dominance of a single flow path, which is consistent with the structure of epigenic cavesSo, in order to explain the structure of maze caves, one has to explain why no single flow path attains dominanceThe retrograde solubility of calcite coupled with heat transfer from the fluid to the rock is hypothesized to provide the mechanism by which dissolutional power is distributed among all competing flow pathsNumerical models of fluid flow, heat transfer, and calcite dissolution chemistry are integrated to develop a model of hypogene cave initiation in fractured limestoneFlow is assumed to occur in the presence of a spatially variable rock temperature field that is constant through timePreliminary numerical modeling results for a system of parallel fractures demonstrate the differences in the nature of competition between flow paths in epigenic (constant temperature) and hypogenic systems (flow in the presence of a negative thermal gradient)Differences in results using various kinetic models for calcite dissolution are also presentedThe role of aperture variation and distribution in a parallel set of fractures is also examined

Perspectives in karst hydrogeology and cavern genesis, 1999, Ford D. C.
Hydrogeology and speleology both began during the 19th CenturyTheir approaches to limestone aquifers diverged because hydrogeologists tend to measure phenomena at very local scales between drilled wells and generalize from them to basin scales, while speleologists study the large but sparse conduits and then infer conditions around themConvergence of the two approaches with modem computing should yield important genetic models of aquifer and caveGenesis of common cave systems by dissolution is a three-dimensional problem, best broken down into two-dimensional pairs for purposes of analysisHistorically, the dimensions of length and depth have received most attention, especially the question of the location of principal cave genesis with respect to the water tableBetween 1900 and 1950, different scientists proposed that caves develop principally (1) in the vadose zone; (2) at random depth in the phreatic zone; (3) along the water table in betweenEmpirical evidence suggests that these differing hypotheses can be reconciled by a four-state model in which the frequency of penetrable fissuration controls the system geometryFor the dimensions of length and breadth (plan patterns) there is widespread agreement that dendritic (or branchwork) patterns predominate in common cavesIrregular networks or anastomose patterns may occur as subsidiary componentsWhen hydraulic conditions in a fissure are anisotropic (the usual case), dissolutional conduit development is competitive: local hydraulic gradients are reoriented toward the first conduits to break through to outlet points, redirecting others toward them in a cascading processPlan patterns are most complex where there have been multiple phases ("levels") of development in a cave system in response to such effects as river channel entrenchment lowering the elevation of springs

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