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 compass is an instrument with a magnetic needle which is free to point to magnetic north. for survey the needle is either attached to a graduated card or can be read against a graduated circle to measure the angle in degrees from the north clockwise [25].?

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 chambers (Keyword) returned 88 results for the whole karstbase:
Showing 16 to 30 of 88
Contribution ltude du karst et des grottes du Kaokoland (Namibie), 1999, Martini J. E. J. , Marais J. C. E. , Irish J.
The authors describe the dolomite karst of Kaokoland, an arid region of Namibia, which had been very poorly investigated speleologically. The geomorphology, the karst hydrology and the water chemistry are reviewed. Although the karst area is large, caves are scarce and usually reduced to single large chambers. Integrated networks of passages are appa_rently missing. Seven caves are described in detail, including their mineralogy which comprise rare species. The Kookoland karst is compa_red with other ones develo_ped in more humid areas of Southern Africa. A speleogenetic model is proposed, which involves mixing of near surface ground water with anoxic sulphide-rich water of deep origin and could explain the very localised forma_tion of large cavities.

Radon concentration changes in the air of two caves in Poland, 1999, Przylibski T. A. ,
The paper presents spatial and seasonal radon concentration changes in the air of two caves in Poland on the basis of measurements during 1995-1997. A process of seasonal radon concentration changes in the caves' air was identified, based on research on radon occurrence in caves carried out for over 20 years. A major role in this process was ascribed to ventilation caused by atmospheric temperature changes. High radon concentrations are observed in the warm half-year (May-August), when the average air temperature exceeds the average temperature of the cave interior. Low concentrations occur, however, in the cold half-year (December-January), and a relatively sharp increase or decrease in radon concentration is related to changes in atmospheric temperatures relative to the average temperature in the cave interior. The amplitude of these radon concentration changes may reach several kBq m(-3). In the Radochowska Cave the lowest monthly radon concentration (0.06 kBq m(-3)) was recorded in December 1996, while the highest (1.37 kBq m(-3)) was observed in August 1996. In the Niedzwiedzia Cave the lowest value (0.10 kBq m(-3)) was observed in January 1997 and the highest (4.18 kBq m(-3)) was noted in March 1997. The spatial variation of radon concentrations is mainly due to the morphology of the chambers and corridors of a cave, and by the distance between the measurement point and the entrance holes. As a rule, locations further from the entrance have poorer ventilation and higher radon concentrations. (C) 1999 Elsevier Science Ltd. All rights reserved

La grotte et le karst de Cango (Afrique du Sud), 2000, Martini, J. E. J.
The author describes a small karst area in the extreme south of the African Continent, with special reference to the Cango Cave, which is a major tourist attraction. Compared with the other karsts of Southern Africa, this area is unique. The karst is typically exogenic, with caves forming by stream disappearance into swallow holes, where the thalweg intersects steeply dipping Precambrian limestone. Wet caves are vadose, with only short phreatic segments and exhibit rectilinear, longitudinal sections. Passages are low, but wide with bevelled ceilings, often terraced. This peculiar morphology is typical of the caves developing exactly on the water-table and seems to be controlled by the abundance of sediments introduced from the swallow holes. If one excepts a short active lower level, Cango is a dry cave of the same type than the wet ones. It is practically linear in plan and in profile, with a length of 2.6 km from entrance to end for a total of 5.2 km of passages. The age of the speleogenesis has been estimated as early Pleistocene from the entrance elevation, which is in between the altitude of the actual thalweg and the one of the Post African I erosion surface, which started to be eroded during the Upper Pliocene. This relatively young age is in contrast with a Miocene model, which was accepted by most of the previous authors. Cango is well adorned with speleothems, in particular with outstanding abundant shields, monocrystalline stalagmites and pools coated with calcite crystals. In the first chambers from entrance, the speleothems have been deeply corroded by bat guano, with deposition of hydroxylapatite. Previously this corrosion was attributed to resolution due to several rises of the paleowater-table. The meteorology is discussed, in particular the high carbon dioxide, which indicates that the cave is poorly ventilated and which constitutes a problem for management and conservation.

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

Patterns of collapse chambers in the endokarsts of Mallorca (Balearic Islands, Spain), 2000, Giné, S À, Ngel

A general overview on the patterns of collapse chambers in the karsts of Mallorca is presented. The great significance of single breakdown chambers and strings of large rooms as one of the major constituents of cave patterns is easy to recognize in the cave surveys of many Majorcan caves. Detailed mapping of several collapse features such as breakdown piles, sloped boulder floors, vault profiles, coalescence areas, boulder chokes and dome structures can yield useful information regarding description and better understanding of cave collapse patterns.


Modelling the stability of a very large cave chamber; case study: Brezno pri Medvedovi konti, 2000, Kortnik Jož, E, Š, Uš, Terš, Ič, France

The big chamber in Brezno pri Medvedovi konti (Julian Alps, Slovenia), about 150 m wide, over 50 m high and with a volume of about 62 ¥ 104 m3, is the second largest cave chamber yet discovered in Slovenia. Application of FLAC computer software enabled modelling of the stability of the chamber's arched roof during hypothetical denudational lowering of the overlying surface. Modelling was based on two sets of rock property parameters generally attributed to the local parent rock. In both cases the modelled deformation within the arch was at a minimum at a residual ceiling thickness of 20 to 30 m, whereas collapse occurred when the residual ceiling thickness reduced to about 4 m. These modelling results fit well with field observations of partly collapsed cave chambers.


Cave Temperatures at Naracoorte Caves, 2002, Sanderson Ken , Bourne Steven
Temperatures in four different caves at Naracoorte were logged for periods of up to two years, during 1998-2001. In Bat Cave temperatures near ground level were 19.0-21.1C in the maternity chamber, and 10.3-15.6C near the entrance. In Victoria Fossil Cave temperatures near the fossil chamber were 16.9-18.3C. In Blanche Cave and the outer chamber of Robertson Cave temperatures were 9.4-15.0C, with temperatures in the inner chamber of Robertson Cave 14.2-15.0C. Cave chambers with little air flow had seasonally stable temperatures, and those with high air flow showed seasonal temperature variations of 5-6C.

Existence of karsts into silicated non-carbonated crystalline rocks in Sahelian and Equatorial Africa, hydrogeological implications, 2002, Willems Luc, Pouclet Andre, Vicat Jean Paul,
Various cavities studied in western Niger and South Cameroon show the existence of important karstic phenomena into metagabbros and gneisses. These large-sized caves resulted from generalized dissolution of silicate formations in spite of their low solubility. Karstification is produced by deep hydrous transfer along lithological discontinuities and fracture net works. The existence of such caves has major implications in geomorphology, under either Sahelian and Equatorial climate, and in hydrogeology and water supply, particularly in the Sahel area. Introduction. - Since a few decades, several karst-like morphologies are described in non-carbonated rocks (sandstones, quartzites, schistes, gneisses...) [Wray, 1997 ; Vicat and Willems, 1998 ; Willems, 2000]. The cave of Guessedoundou in West Niger seems to be due to a large dissolution of metagabbros. The cave of Mfoula, South Cameroon, attests for the same process in gneisses. This forms proof that big holes may exist deeper in the substratum even of non-carbonated silicate rocks. Their size and number could mainly influence the landscape and the hydrogeology, especially in the Sahelian areas. Guessedoundou, a cave into metagabbros in West Niger. - The site of Guessedoundou is located 70 km south-west of Niamey (fig. 1). The cave is opened at the top of a small hill, inside in NNE-SSW elongated pit (fig. 2 ; pl. I A). The hole, 3 to 4 m deep and 20 m large, has vertical walls and contains numerous sub-metric angular blocks. A cave, a few meters deep, comes out the south wall. Bedrocks consist of metagabbros of the Makalondi greenstone belt, a belt of the Palaeoproterozoic Birimian Formations of the West Africa craton [Pouclet et al., 1990]. The rock has a common granular texture with plagioclases, partly converted in albite and clinozoisite, and pyroxenes pseudomorphosed in actinote and chlorite. It is rather fairly altered. Chemical composition is mafic and poorly alkaline (tabl. I). A weak E-W schistosity generated with the epizonal thermometamorphism. The site depression was created along a N010o shear zone where rocks suffered important fracturation and fluid transfers, as shown by its silification and ferruginisation. The absence of human activity traces and the disposition of the angular blocks attest that the pit is natural and was due to the collapse of the roof of a vast cavity whose current cave is only the residual prolongation. To the vertical walls of the depression and at the cave entry, pluridecimetric hemispheric hollows are observed (pl. I B). Smooth morphology and position of these hollows sheltered within the depression dismiss the assumptions of formation by mechanical erosion. In return, these features are typical shape of dissolution processes observed into limestone karstic caves. That kind of process must be invoked to explain the opening of the Guessedoundou cave, in the total lack of desagregation materials. Dissolution of metagabbro occurred during hydrous transfer, which was probably guided by numerous fractures of the shear zone. Additional observations have been done in the Sirba Valley, where similar metabasite rocks constitute the substratum, with sudden sinking of doline-like depressions and evidence of deep cavities by core logging [Willems et al., 1993, 1996]. It is concluded that karstic phenomena may exist even in silica-aluminous rocks of crystalline terrains, such as the greenstones of a Precambrian craton. Mfoula a cave into gneisses in South Cameroon. - The cave of Mfoula is located 80 km north-east of Yaounde (fig. 3). It is the second largest cave of Cameroon, more than 5,000 m3, with a large opening in the lower flank of a deep valley (pl. I C). The cavity is about 60 m long, 30 m large and 5 to 12 m high (fig. 4; pl. I D). It is hollowed in orthogneisses belonging to the Pan-African Yaounde nappe. Rocks exhibit subhorizontal foliation in two superposed lithological facies: the lower part is made of amphibole- and garnet-bearing layered gneisses, and the upper part, of more massive granulitic gneisses. Average composition is silico-aluminous and moderately alkaline (tabl. I). The cave is made of different chambers separated by sub-cylindrical pillars. The ceiling of the main chamber, 6 m in diameter, is dome-shaped with a smooth surface (D, fig. 4). The walls have also a smooth aspect decorated with many hemispherical hollows. The floor is flat according to the rock foliation. They are very few rock debris and detrital fragments and no traces of mechanical erosion and transport. The general inner morphology is amazingly similar to that of a limestone cave. The only way to generate such a cavity is to dissolve the rock by water transfer. To test the effect of the dissolution process, we analysed a clayey residual sampled in an horizontal fracture of the floor (tabl. I). Alteration begins by plagioclases in producing clay minerals and in disagregating the rock. However, there is no more clay and sand material. That means all the silicate minerals must have been eliminated. Dissolution of silicates is a known process in sandstone and quartzite caves. It may work as well in gneisses. To fasten the chemical action, we may consider an additional microbial chemolitotrophe activity. The activity of bacteria colonies is known in various rocks and depths, mainly in the aquifer [Sinclair and Ghiorse, 1989 ; Stevens and McKinley, 1995]. The formation of the Mfoula cave is summarized as follow (fig. 5). Meteoric water is drained down along sub-vertical fractures and then along horizontal discontinuities of the foliation, particularly in case of lithological variations. Chemical and biological dissolution is working. Lateral transfers linked to the aquifer oscillations caused widening of the caves. Dissolved products are transported by the vertical drains. Regressive erosion of the valley, linked to the epeirogenic upwelling due to the volcano-tectonic activity of the Cameroon Line, makes the cavities come into sight at the valley flanks. Discussion and conclusion. - The two examples of the Guessedoundou and Mfoula caves evidence the reality of the karsts in non-carbonated silicated rocks. The karst term is used to design >> any features of the classical karst morphology (caves, dolines, lapies...) where dissolution plays the main genetical action >> [Willems, 2000]. Our observations indicate that (i) the karst genesis may have occurred into any kind of rocks, and (ii) the cave formation is not directly dependent of the present climate. These facts have major consequences to hydrogeological investigations, especially for water supply in Sahelian and sub-desertic countries. Some measurements of water transfer speed across either sedimentary pelitic strata of the Continental terminal or igneous rocks of the substratum in West Niger [Esteves and Lenoir, 1996 ; Ousmane et al., 1984] proved that supplying of aquifers in these silico-aluminous rocks may be as fast as in a karstic limestone. That means the West Niger substratum is highly invaded by a karstic net and may hidden a lot of discontinuous aquifers. The existence of this karst system can be easily shown by morphological observations, the same that are done in karstic limestone regions (abnormally suspended dry valleys, collapses, dolines...). Clearly, this must be the guide for any search of water, even in desertic areas where limestones are absent

Eogenetic karst from the perspective of an equivalent porous medium, 2002, Vacher H. L. , Mylroie J. E. ,
The porosity of young limestones experiencing meteoric diagenesis in the vicinity of their deposition (eogenetic karst) is mainly a double porosity consisting of touching-vug channels and preferred passageways lacing through a matrix of interparticle porosity. In contrast, the porosity of limestones experiencing subaerial erosion following burial diagenesis and uplift (telogenetic karst) is mainly a double porosity consisting of conduits within a network of fractures. The stark contrast between these two kinds of karst is illustrated by their position on a graph showing the hydraulic characteristics of an equivalent porous medium consisting of straight, cylindrical tubes (n-D space, where n is porosity, D is the diameter of the tubes, and log n is plotted against log D). Studies of the hydrology of small carbonate islands show that large-scale, horizontal hydraulic conductivity (K) increases by orders of magnitude during the evolution of eogenetic karst. Earlier petrologic studies have shown there is little if any change in the total porosity of the limestone during eogenetic diagenesis. The limestone of eogenetic karst, therefore, tracks horizontally in n-D space. In contrast, the path from initial sedimentary material to telogenetic karst comprises a descent on the graph with reduction of n during burial diagenesis, then a sideways shift with increasing D due to opening of fractures during uplift and exposure, and finally an increase in D and n during development of the conduits along the fractures. Eogenetic caves are mainly limited to boundaries between geologic units and hydrologic zones: stream caves at the contact between carbonates and underlying impermeable rocks (and collapse-origin caves derived therefrom); vertical caves along platform-margin fractures; epikarst; phreatic pockets (banana holes) along the water table; and flank margin caves that form as mixing chambers at the coastal freshwater-saltwater 'interface'. In contrast, the caverns of telogenetic karst are part of a system of interconnected conduits that drain an entire region. The eogenetic caves of small carbonate islands are, for the most part, not significantly involved in the drainage of the island

Cave Temperatures at Naracoorte Caves, 2002, Sanderson Ken , Bourne Steven

Temperatures in four different caves at Naracoorte were logged for periods of up to two years, during 1998-2001. In Bat Cave temperatures near ground level were 19.0-21.1°C in the maternity chamber, and 10.3-15.6°C near the entrance. In Victoria Fossil Cave temperatures near the fossil chamber were 16.9-18.3°C. In Blanche Cave and the outer chamber of Robertson Cave temperatures were 9.4-15.0°C, with temperatures in the inner chamber of Robertson Cave 14.2-15.0°C. Cave chambers with little air flow had seasonally stable temperatures, and those with high air flow showed seasonal temperature variations of 5-6°C.


Karst development on carbonate islands, 2003, Mylroie J. E. , Carew J. L.

Karst development on carbonate platforms occurs continuously on emergent portions of the platform. Surficial karst processes produce an irregular pitted and etched surface, or epikarst. The karst surface becomes mantled with soil, which may eventually result in the production of a resistant micritic paleosol. The epikarst transmits surface water into vadose pit caves, which in turn deliver their water to a diffuse-flow aquifer. These pit caves form within a 100,000 yr time frame. On islands with a relatively thin carbonate cover over insoluble rock, vadose flow perched at the contact of carbonate rock with insoluble rock results in the lateral growth of vadose voids along the contact, creating large collapse chambers that may later stope to the surface.
Carbonate islands record successive sequences of paleosols (platform emergence) and carbonate sedimentation (platform submergence). The appropriate interpretation of paleosols as past exposure surfaces is difficult, because carbonate deposition is not distributed uniformly, paleosol material is commonly transported into vadose and phreatic voids at depth, and micritized horizons similar in appearance to paleosols can develop within existing carbonates.
On carbonate islands, large dissolution voids called flank margin caves form preferentially in the discharging margin of the freshwater lens from the effects that result from fresh-water/salt-water mixing. Similarly, smaller dissolution voids also develop at the top of the lens where vadose and phreatic fresh-waters mix. Independent of fluid mixing, oxidation of organic carbon and oxidation/reduction reactions involving sulfur can produce acids that play an important role in phreatic dissolution. This enhanced dissolution can produce caves in fresh-water lenses of very small size in less than 15,000 yr. Because dissolution voids develop at discrete horizons, they provide evidence of past sea-level positions. The glacio-eustatic sea-level changes of the Quaternary have overprinted the dissolutional record of many carbonate islands with multiple episodes of vadose, fresh-water phreatic, mixing zone, and marine phreatic conditions. This record is further complicated by collapse of caves, which produces upwardly prograding voids whose current position does not correlate with past sea level positions.
The location and type of porosity development on emergent carbonate platforms depends on the degree of platform exposure, climate, carbonate lithology, and rate of sea-level change. Slow, steady, partial transgression or regression will result in migration of the site of phreatic void production as the fresh-water lens changes elevation and moves laterally in response to sea-level change. The result can be a continuum of voids that may later lead to development solution-collapse breccias over an extended area.


Das Untertagelabor in den Obir-Hhlen., 2004, Sptl, Ch.
The Obir Caves in the southern part of the province of Carinthia are among the best known dripstone caves in Austria. These caverns were only discovered as a result of mining operations during the 19th century and parts of them were adapted as a show cave which was opened in 1991. In a cave system adjacent to the show cave and not open to the public, an underground research station was set up in 1998 and has been in operation since then. This laboratory encompasses a total of six automatic drip water measurement stations in two cave chambers, as well as air temperature data loggers. On regular cave visits every one to two months since 1998, a series of manual measurements (e.g., partial pressure of CO2) and water and cave air samples have been taken. Compositional parameters determined on site include pH, electric conductivity and carbonate alkalinity. Parameters determined in laboratories elsewhere include cations (Na, K, Ca, Mg, Sr), anions (Cl, F, NO3, SO4), dissolved silica and stable isotopes (dD, d18O, d13CDIC, d13Cair). These measurements are complemented by soil studies above the cave (soil temperature and soil water chemistry, rainwater composition).[Obir-Hhlensystem]

Das Untertagelabor in den Obir-Hhlen, 2004, Sptl, Ch.
The Obir Caves in the southern part of the province of Carinthia are among the best known dripstone caves in Austria. These caverns were only discovered as a result of mining operations during the 19th century and parts of them were adapted as a show cave which was opened in 1991. In a cave system adjacent to the show cave and not open to the public, an underground research station was set up in 1998 and has been in operation since then. This laboratory encompasses a total of six automatic drip water measurement stations in two cave chambers, as well as air temperature data loggers. On regular cave visits every one to two months since 1998, a series of manual measurements (e.g., partial pressure of CO2) and water and cave air samples have been taken. Compositional parameters determined on site include pH, electric conductivity and carbonate alkalinity. Parameters determined in laboratories elsewhere include cations (Na, K, Ca, Mg, Sr), anions (Cl, F, NO3, SO4), dissolved silica and stable isotopes (dD, d18O, d13CDIC, d13Cair). These measurements are complemented by soil studies above the cave (soil temperature and soil water chemistry, rainwater composition).

Die Klarahhle im Sengsengebirge (Obersterreich)., 2005, Steinmassl, H.
Klarahhle is situated in the Kalkalpen National Park and was discovered in autumn 1999 by Heli Steinmassl. Several kilometers of tunnel-like passages on a hitherto unknown horizontal level, enormous chambers and in some parts extraordinarily beautiful and gigantic stalagtites and stalagmites make this giant cave a very special treasure in the heart of the national park. It took the local team of speleologists only four and a half years to survey a total length of 23,018 m and to explore two more kilometers. By acting very carefully in exploring this speleothemcavern it remained untouched and in its original state. Sensible parts were barred with ribbons to protect them even against speleologists themselves. In April 2005 the cave was put under protection applying strict rules and gated. It offers an interesting field of research to scientists and explorers and it also enriches the Kalkalpen National Park by a whole new dimension. [Klarahhle im Nationalpark Kalkalpen, Gesamtlnge: 23.018 m vermessen und 2 km erkundet. Schutzmanahmen, bersichtsgrundriss, Raumbeschreibungen, Forschungsgeschichte, zoologische Beobachtungen]

Escherichia coli survival in mantled karst springs and streams, northwest Arkansas Ozarks, USA, 2005, Davis Rk, Hamilton S, Van Brahana J,
Recent studies indicate fecal coliform bacterial concentrations, including Escherichia coli (E. coli), characteristically vary by several orders of magnitude, depending on the hydrology of storm recharge and discharge. E. coli concentrations in spring water increase rapidly during the rising limb of a storm hydrograph, peak prior to or coincident with the peak of the storm pulse, and decline rapidly, well before the recession of the storm hydrograph. This suggests E. coli are associated with resuspension of sediment during the onset of turbulent flow, and indicates viable bacteria reside within the spring and stream sediments. E. coli inoculated chambers were placed in spring and stream environments within the mantled karst of northwest Arkansas to assess long term (> 75 days) E. coli viability. During the 75-day study, a 4-log die-off of E. coli was observed for chambers placed in the Illinois River, and a 5-log die-off for chambers placed in Copperhead Spring. Extrapolation of the regression line for each environment indicates E. coli concentration would reach 1 most probable number (MPN)/100 g sediment at Copperhead Spring in about 105 days, and about 135 days in the Illinois River, based on a starting inoculation of 2.5 x 107 MPN E. coli/100 g of sediment. These in situ observations indicate it is possible for E. coli to survive in these environments for at least four months with no fresh external inputs

Results 16 to 30 of 88
You probably didn't submit anything to search for