Karst and Cave RSS news feed Like us on Facebook! follow us on Twitter!
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. ...

Speleology in Kazakhstan

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

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

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

The deepest terrestrial animal

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

Caves - landscapes without light

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

Did you know?

That crest line is line connecting crests [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.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
See all featured articles
Featured articles from other Geoscience Journals
Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
See all featured articles from other geoscience journals

Search in KarstBase

Your search for fractures (Keyword) returned 335 results for the whole karstbase:
Showing 1 to 15 of 335
Conduit enlargement in an eogenetic karst aquifer, , Moore Paul J. , Martin Jonathan B. , Screaton Elizabeth J. , Neuhoff Philip S.

Most concepts of conduit development have focused on telogenetic karst aquifers, where low matrix permeability focuses flow and dissolution along joints, fractures, and bedding planes. However, conduits also exist in eogenetic karst aquifers, despite high matrix permeability which accounts for a significant component of flow. This study investigates dissolution within a 6-km long conduit system in the eogenetic Upper Floridan aquifer of north-central Florida that begins with a continuous source of allogenic recharge at the Santa Fe River Sink and discharges from a first-magnitude spring at the Santa Fe River Rise. Three sources of water to the conduit include the allogenic recharge, diffuse recharge through epikarst, and mineralized water upwelling from depth. Results of sampling and inverse modeling using PHREEQC suggest that dissolution within the conduit is episodic, occurring only during 30% of 16 sampling times between March 2003 and April 2007. During low flow conditions, carbonate saturated water flows from the matrix to the conduit, restricting contact between undersaturated allogenic water with the conduit wall. When gradients reverse during high flow conditions, undersaturated allogenic recharge enters the matrix. During these limited periods, estimates of dissolution within the conduit suggest wall retreat averages about 4 × 10−6 m/day, in agreement with upper estimates of maximum wall retreat for telogenetic karst. Because dissolution is episodic, time-averaged dissolution rates in the sink-rise system results in a wall retreat rate of about 7 × 10−7 m/day, which is at the lower end of wall retreat for telogenetic karst. Because of the high permeability matrix, conduits in eogenetic karst thus enlarge not just at the walls of fractures or pre-existing conduits such as those in telogenetic karst, but also may produce a friable halo surrounding the conduits that may be removed by additional mechanical processes. These observations stress the importance of matrix permeability in eogenetic karst and suggest new concepts may be necessary to describe how conduits develop within these porous rocks.


The Aggitis karst system, Eastern Macedonia, Greece: Hydrologic functioning and development of the karst structure, , Novel Jean Paul, Dimadi Agoro, Zervopoulou Anna, Bakalowicz Michel,
SummaryThe Aggitis karst system developed in the marbles of the Rhodope massif. The conditions of the development of its karst drainage network are determined from the geological and geomorphologic settings by means of a microstructural analysis, following Eraso's method. This analysis shows that the karst conduit network intensely developed in the western part of the mountain Falakro where the majority of the open fractures oriented in the same direction as the hydraulic gradient, while the two directions are perpendicular in its eastern part drained by the spring of Drama.The behaviour of the system was analysed by means of hydrodynamic and water geochemical techniques. Despite the extension of the cave system and of the favourable development conditions of conduits, the functioning appears complex, with a significant storage, and a slow infiltration as well as an easy drainage. On the contrary the Drama karst system, characterised by a low variability in its hydrological and geochemical characteristics does not show any karst functioning.In the Aggitis karst system the initial groundwater flow conditions in combination with the aperture planes of which the directions are in agreement with the hydraulic gradient, favoured the rapid development of a drainage network system. The recharge from a large surface catchment area on non-karstic rocks, through swallow holes in a wide polje contributed to increase the groundwater flow through the karst part of the system, facilitating the development of the conduits

Processes of limestone cave development., 1964, Howard Alan D.
Three processes successively predominate in enlarging original fractures within limestone into cavern passages: (I) early dissolving by acid produced by oxidizing reactions within the groundwater as it flows through the limestone; (2) dissolving caused by the initial undersaturation with respect to calcite of the groundwater when it enters the limestone; and (3) increased dissolving which occurs at the transition from laminar to turbulent groundwater flow. Only those original fractures in limestone which are widest and which have a high hydraulic gradient acting across them will be enlarged into cavern passages. Until all available surface drainage has been diverted underground, cavern development takes place under a constant hydraulic head, and the rate of limestone solution increases with time. After all available surface drainage has been diverted underground, the discharge through the cave, rather than the hydraulic head, remains constant, and the rate of limestone solution decreases toward a constant value. These principles apply to caverns formed both by water-table flow and by artesian flow.

Relations of jointing to orientation of solution cavities in limestones of central Pennsylvania, 1969, Deike Rg,
Twenty-six caves in central Pennsylvania were divided into passage segments inferred to have formed along the strike of fracture planes. For each cave passage, bearings weighted by footage were used to calculate an average passage orientation. Fractures measured at outcrops near the caves were classed by strike of subparallel sets which were cumulated by frequency for preferred orientations. Average passage orientation compared with orientation of fracture frequency was significant to the 95 percent level. Thus, caves develop more footage parallel to the strike of the more abundant fractures. Solution passages can therefore be used as one determinant of the local fracture system, and a selective solution process may be related to the mechanical origin of the fractures as well as their frequency

Geomorphology of the North Karst, South Nahanni River Region, Northwest Territories, Canada, PhD Thesis, 1976, Brook, George Albert,

First investigated on the ground in June 1972, the Nahanni karst of northern Canada is the most complex karst terrain yet reported from high latitudes. It is centered at 61°28' N, longitude 124°05' W and lies within the zone of discontinuous permafrost. Mean annual temperature is 24°F and mean total precipitation 22.3 inches. Principal karst forms are fracture-located karst streets and irregularly-shaped closed depression called karst platea which may be up to 600 feet in depth. Platea often contain karst towers which are residuals of wall recession. Vertical-walled pond dolines up to 120 feet deep are common in bare karst areas while subjacent karst collapse, subsidence and suffosion depressions occur on marginal shale- and drift-mantled surfaces. Three small poljes have been identified, two produced entirely by solution, the other a structural form. These are periodically inundated. There are several peripheral fluvial canyons up to 3,000 feet deep that are blocked by glacial drift and which presently drain underground. Similarity in the hydrogeological properties of Nahanni Formation limestones at a variety of scales has led to the development of morphologically-identical karst forms which range in size from inches up to hundreds of feet. Furthermore, many of these landforms are part of a developmental sequence that at one scale links vertical-walled dolines, karst streets, platea and poljes; and at another links solution pits, grikes and joint hollows on limestone pavements. The evidence suggests that poljes form by the coalescence of dolines and uvalas just as Cvijic suggested in 1918. In attempting to explain the almost "tropical" nature of the sub-arctic Nahanni karst landform assemblage, a number of facts are of importance.
(a) The Nahanni Formation limestones have been highly warped and intensively fractures during the past one million years. Open fractures have encouraged karstification by allowing easy movement of water underground. Warping has provided the relief necessary for the development of solutional forms with a distinct vertical component.
(b) The karst can not be considered relict because it was glaciated during the Pleistocene. In addition the hydrological activity in it today is comparable with that in many humid tropical karst areas.
(c) Solutional denudation rates governed by aspects of surficial and bedrock geology may in some localized areas be equivalent to rates in humid tropical carbonate regions.
(d) At present rates, the most highly developed forms could have been produced within the last 200,000 years and because there is evidence to indicate that the karst may not have been glaciated for up to 250,000 years, such a period has been available for solutional development.
Because the Nahanni region has not been glaciated for an extremely long period, it may be one of only a few high-latitude carbonate terrains that have had time to develop fully. Its very existence questions the validity of the concept that the intensity and direction of karst development is climate-controlled. In the Nahanni at least, the structural and lithological properties of the host limestone appear to have been of greater importance. The labyrinth karst type present in regions of humid-tropical to sub-arctic climate, is an outstanding example of a structurally-controlled karst landscape. It may well be that the same controls also influence the distributions of other karst types.


Diffuse flow and conduit flow in limestone terrain in the Mendip Hills, Somerset (Great Britain), 1977, Atkinson T. C.
The hydrogeology of the karstic Carboniferous Limestone is described. Water tracing has established recharge areas for fifteen major springs and water budgets confirm the size of the areas found. Groundwater flow occurs in two modes: turbulent conduit flow and diffuse Darcian flow in fine fractures. Recharge is 50% quickflow via caves and closed depressions and 50% slower percolation. Active storage in the diffuse component (S = 0.92%) is 30 times greater than in phreatic conduits. Diffuse hydraulic conductivity is 0.89 m day−1 and an average of 60?80% of groundwater is transmitted by conduits in this maturely karsted and steeply dipping aquifer.

Fracturation and Karstification of a Massif: the example of the Azerou El Kebir (Northern Algeria)., 1978, Coiffait P. E. , Quinif Yves
The fracturation of the sub-autochthonous massif of the Azerou el Kebir is not fundamentally different from that of the adjoining allochthonous massif; where the structures are due to an Alpine phase, known as the Atlas phase. As with all fractures, karstification only exploits certain of them, without having any linkage to their statistical importance, caves have developed following fractures which are qualitatively important, but are poorly represented quantitatively. The study of the karstification therefore, confirms his complementary to the structural analysis in order to elucidate the technical problems of fracturation in the region.

Etude des circulations d'air dans la grotte de Niaux, 1983, Andrieux, C.
THE AIR MOVEMENTS IN THE grotte DE NIAUX. CONSEQUENCES - The present paper deals with air movements in the grotte de Niaux (Arige, France) during ten years (1971-1980). The data (observations, measurements) have been obtained, upon an average, each week; they relate to the direction of underground air movements, to the speed and to average air flow, which have been measured at some places, at cave entrances. The results show two types of air movements. In the first one, the gas exchanges between the cave and outside happen through the galleries and the known entrances and also through all the fractures of the carbonate rocks. When it occurs, the cave can be divided in three main parts, each one having their own characteristics. The second one is observed only during very rainy times; the whole cave is then subjected to air movement according to the "wind tube model". The air exchanges through the fractures are fixed by the percolation. The percolation zone is consequently submitted to diphasic water flow. Therefore, different models of air movements in caves must be considered. These data also show it is needful that the airflow should be measured to understand the climatic phenomena of the caves.

Le rseau de la Diau, 1983, Lismonde, B.
The DIAU SYSTEM - Diau Cave is the resurgence of an important underground drainage system in the massif des Bornes in Haute-Savoie (France). The system's catchment is approximately 9km2, between an altitude of 1200m and 1800m. The average discharge is about 4001/s. Speleological explorations have discovered two sections of the master drainage cave (Diau and Pertuis caves). Two tributaries have also been explored. The total length of the Diau cave system is 14.9km with a height difference of 702m. The master cave occurs in the bottom of the Pertuis syncline at the boundary between the urgonian limestone and hauterivian marls. According to the gradient and the fractures, four types of gallery structure occur, of which two are vadose. The two known tributaries (inlet of the Grenoblois and Tanne des Mtores) follow a NW-SE anticlockwise shear fault, which exists in the Parmelan plateau fracture zone.

Hydrology of autogenic percolation systems in some tropical karst outcrops, West Malaysia, 1983, Crowther J,
This paper reports on the flow regimes of underground seepages in three tower-karst outcrops and in the Setul Boundary Range, West Malaysia. Groundwater movement in the tower-karst hills, which comprise very pure, massive marbles, is confined to vertical and subvertical joints. Although flow is primarily diffuse and the discharges of the majority of seepages correlate most closely with rainfall in antecedent periods of 1-16 days or more, some stormflow occurs along conduits in the upper parts of these aquifers. Many of these conduits appear to peter out at depth into tight rock fractures, thereby forming funnel-shaped underground reservoirs which serve to moderate discharge variations. In contrast, the limestones of the Setul Boundary Range are less pure and retain much of their original bedding. The presence of near-horizontal bedding plane fractures favours lateral groundwater movement and the development of integrated drainage networks within the rock. Compared with the tower-karst caves, seepage rates are generally higher and more responsive to short-term variations in rainfall. The marked difference in topography between the tower-karst hills and the Setul Boundary Range is largely attributable to the contrasted geohydrological properties of the limestones

Un karst subalpin mditerranen : la rgion Audibergue-Mons (Alpes-Maritimes et Var), 1984, Julian M. , Nicod J.
THE KARSTIC AREA AUDIBERGUE-MONS (Prealps of Grasse, Maritime Alps and Var departments) - This area, very important for the karstic superficial features and the caves, is formed by the proximity of plateaus belonging to the structural system of Provence and the higher main subalpine unit of Audibergue. Three fields of sinkholes are especially characteristic: 1/ central Audibergue, controlled by shear fractures and under the influence of nival phenomena; 2/ Fort d'Esclapon, with more various forms and perhaps an older karstic evolution that explains the large inheritance of terra rossa; 3/ Biron that shows deep furrows and sinkholes. The study of the poljes, fluvio-karstic (Caille) or half-opened (Canaux), introduces the problem of the underground karstic hydrology. The dynamics of neotectonics and morphoclimatic systems, specially the old periglacial processes, is considered with reference to the main forms and deposits shown on the map.

Formes de relief pseudokarstiques sur Mars, 1985, Battistini, R.
PSEUDOKARST LANDFORMS ON MARS - There are many morphologic features on Mars looking like karstic features, principally in aeolian, glacio-eolian and volcanic formations: etch-pitted terrain, sinkholes aligned along fractures, sinuous alignments of large cavities similar to megadolines, etc. Some of these features are probably collapse features, and some others probably thermokarstic features but it is difficult to understand exactly the process of their genesis, in some cases very different from the process of terrestrial morphologic features. We may evoke the possibility of an underground karst on Mars.

Techniques gophysiques de type lectromagntiques appliques l'tude du karst nivernais, 1985, Couturaud A. , Benderitter Y.
STUDY OF KARSTIC DRAINS ENVIRONMENT BY GEOPHYSICAL TECHNIQUES (ELECTRIC AND ELECTROMAGNETIC) - Geophysical techniques (electric and electromagnetic) are tested on two underground rivers of the Nivernais karst (Bourgogne, France). The first site is an important dry valley and the second locates at the border of a plateau. No sharp image of the known galleries were obtained on both sites, but the first one shows a higher density of anomalies corresponding to the cave. In the axis of the valley is a weak resistivity anomaly, without any relation with the karstic drainage and which has not superficial origin. This anomaly would be the consequence of a fracturing of bottom valley. Others zones of fractures are evidenced, cross-cutting the conduits. The second one has also weak resistivity zones, independent of the cave, which are interpreted as annex system (hydrological sense). Some reflections on theoretical and methodological aspect of this type of research are proposed.

Le massif du Parmelan, Haute-Savoie, relations fractura-tion-karstification, 1985, Masson, M.
THE MASSIF OF PARMELAN, HAUTE-SAVOIE, FRANCE: RELATIONS BETWEEN FRACTURATION AND KARSTIFICATION - The massif of Parmelan (Haute-Savoie), encloses a well-karstified and highly organised perched aquifer. Its simple geological structure and easy-speleological penetration (more than 45km are known) have allowed a statistical study of the fracturation and karstification parameters at different scales. This study shows that the karst has developed on the most frequent fracturation directions (study of the cumulated lengths), whereas its directional distribution in frequency is relatively homogeneous; the most used fractures are the tension faults, linked with the folding of the massif.

Morphologie et volution des cavernes et formes superficielles dans les quartzites du Roraima, 1988, Galan C. , Lagarde J.
MORPHOGENESIS OF CAVES AND LANDFORMS IN THE PRECAMBRIAN QUARTZITE OF RORAIMA GROUP (VENEZUELA) - This paper describes caves and landforms developed in the Precambrian quartzite of the Roraima Group (1600-1800 My) in the Gran Sabana of Venezuela (cf. Pouyllau and Seurin, in Karstologia, 1985, n 5). High plateaus (Tepuys) are remnants of old erosional surfaces of Secondary-Tertiary age. The weathering of quartzite is produced in fissures by means of the dissolution of the intergranular siliceous cement. Depressions, fields of blocks and small towers, deep fissures characterise the edges of tepuys. Underground passages could be formed by dissolution, arenisation and piping from the fractures which dissect the tepuys. The part of hydrothermalism in speleogenesis is not proved.

Results 1 to 15 of 335
You probably didn't submit anything to search for