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 leakance is 1. the ratio k'/b', in which k' and b' are the vertical hydraulic conductivity and the thickness, respectively, of the confining beds [22]. 2. the rate of flow across a unit (horizontal) area of a semipervious layer into (or out of) an aquifer under one unit of head difference across this layer. synonymous with coefficient of leakage [22].?

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 substances (Keyword) returned 33 results for the whole karstbase:
Showing 1 to 15 of 33
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

Unusual speleothems resembling giant mushrooms occur in Cueva Grande de Santa
Catalina, Cuba. Although these mineral buildups are considered a natural heritage, their
composition and formation mechanism remain poorly understood. Here we characterize
their morphology and mineralogy and present a model for their genesis. We propose that
the mushrooms, which are mainly comprised of calcite and aragonite, formed during four
different phases within an evolving cave environment. The stipe of the mushroom is an
assemblage of three well-known speleothems: a stalagmite surrounded by calcite rafts
that were subsequently encrusted by cave clouds (mammillaries). More peculiar is the
cap of the mushroom, which is morphologically similar to cerebroid stromatolites and
thrombolites of microbial origin occurring in marine environments. Scanning electron
microscopy (SEM) investigations of this last unit revealed the presence of fossilized
extracellular polymeric substances (EPS)—the constituents of biofilms and microbial
mats. These organic microstructures are mineralized with Ca-carbonate, suggesting that
the mushroom cap formed through a microbially-influenced mineralization process. The
existence of cerebroid Ca-carbonate buildups forming in dark caves (i.e., in the absence
of phototrophs) has interesting implications for the study of fossil microbialites preserved
in ancient rocks, which are today considered as one of the earliest evidence for life on
Earth.


Discovery of fluorescent substances in the yellow organ of Caecospaeroma burgundum Dollfus, Isopod Crustacean of underground waters., 1967, Descimon Henry, Marvillet Claude
Chromatographic analysis of the yellow organs of the fresh-water Isopod Crustacean Caecosphaeroma burgundum Dollfus revealed, through observation of the chromatograms in ultraviolet light, the occurrence of both absorbing and fluorescent substances. Among the latter, only isoxanthopterin has been identified. The yellow pigment, which probably has a pteridine nucleus, could not be identified as a known compound and will be the object of later investigations.

On the faculty of absorption of coloured substances by the cuticle of Caecospaeroma burgundum Dollfus, Isopod Crustacean of underground waters., 1967, Graf Franois, Marvillet Claude
The discovery, in certain subterranean waters, of "pigmented," brown or black Caecosphaeroma burgundum, led to the systematic study of the action of pigmented substances on these crustaceans. The results of these experiments demonstrate that the colorations thus obtained or observed in nature are due to the agglutination of coloured substances on the surface of the carapace and, in certain cases, to an impregnation of the cuticle itself.

Discovery of fluorescent substances in the yellow organ of Caecospaeroma burgundum Dollfus, Isopod Crustacean of underground waters., 1967, Descimon Henry, Marvillet Claude
Chromatographic analysis of the yellow organs of the fresh-water Isopod Crustacean Caecosphaeroma burgundum Dollfus revealed, through observation of the chromatograms in ultraviolet light, the occurrence of both absorbing and fluorescent substances. Among the latter, only isoxanthopterin has been identified. The yellow pigment, which probably has a pteridine nucleus, could not be identified as a known compound and will be the object of later investigations.

Investigations into the vertical distribution of organisms and chemical substances in the groundwater in valleys and terraces; methods and first results., 1975, Husmann Siegfried
In the alluvial ground of the river Fulda valley and in the diluvial terrace of the river Weser assortments of tubes of various lengths were sunk into sandy and gravely underground to bring to light groundwater of different depths. The installation of these groundwater pump stations was effectuated by two different methods: 1. with the aid of an apparatus for bringing down bore-holes, 2.by ramming in the pump tubes with the aid of a pneumatic hammer. The first biological and chemical investigations in these subterranean water research stations indicated that the vertical distribution of groundwater organisms and chemical substances in special cases may depend on the nature of subterranean water currents and the infiltration of polluted water into the sandy and gravely underground of valleys and terraces.

A critical review of hypotheses on the origin of vermiculations., 1978, Bini Alfredo, Gori M. Cavalli, Gori Silvio
Mud and clay vermiculations are irregular and discontinuous deposits of incoherent materials, almost ubiquitous, found both inside and outside of caves, overlying limestone or other materials, they are formed from many substances (clay, mud, candle-black, colloidal silica, etc.) also their shape dimensions vary greatly. The following genetical hypotheses have been proposed: fossil fillings; chemico-genetical deposition; biological formation; mechanical deposition from moving water or air; clay-layer drying process (Montoriol-Pous hypothesis); physicochemical deposition from drying liquid films. The last is proposed by the authors who, having discussed the various hypotheses, give many examples and the results of some experiments. They distinguish two types of vermiculations: Type 1 or negative vermiculations Type II or normal vermiculations. The genesis of type I is explained by the Montoriol-Pous hypothesis; these vermiculations are large and made of clay or other colloidal material, and are due to the gradual drying of a layer of clay or other substance. The last stage of this drying process causes the vermiculations to form in a more or less dried state. The vermiculations of the second type are small and thin, much ramified and always with a clear halo around them. Vermiculations consisting of many materials have been observed, usually as macroscopic aggregates. They are caused by the drying of a liquid film containing suspended colloidal particles. The proposed mechanism provides a good explanation of all the observed characteristics of vermiculations.

A bibliographical Synthesis on the toxicity of fluorescent substances used in Hydrology., 1978, Molinari J. , Rochat J.
This synthesis has been established from three recent studies and from a complementary bibliographical research. It resumes the names of fluorescent substances actually used or experimented as tracers in hydrology and draws attention to their uses and relative problems in their uses. The adjoining annex gives an exhaustive use of publications received on the subject (35 titles).

Observations on the behaviour patterns of the Cuban cave fish Lucifuga subterranea Poey (Pisces, Ophidiidae)., 1978, Piquemal M. , Thins Georges
The swimming behaviour and the sensory reactions of the blind Cuban cave fish Lucifuga subterranea Poey were studied on a single individual during a period of 6 months. Mechanical stimulation elicits but slight reactions. Gustatory substances in solution elicit fairly typical motor responses which are not followed by systematic exploration behaviour, the same being true for stimulations by odours of prey. The presence of moving prey provokes an oriented exploration with a slight plunging movement of the kind evidenced in other cave fishes. Actual seizing of the prey requires an active approach of the latter towards the anterior part of the body of the fish.

HIGH-RESOLUTION SEISMIC EXPRESSION OF KARST EVOLUTION WITHIN THE UPPER FLORIDIAN AQUIFER SYSTEM - CROOKED LAKE, POLK COUNTY, FLORIDA, 1994, Evans Mw, Snyder Sw, Hine Ac,
We collected 43 km of high resolution seismic reflection profiles from a 14.5-hectare lake in the central Florida sinkhole district and data from three adjacent boreholes to determine the relationship between falling lake levels and the underlying karst stratigraphy. The lake is separated from karstified Paleogene to early Neogene carbonates by 65-80 m of siliciclastic sands and clays. The carbonate and clastic strata include three aquifer systems separated by clay-confining units: a surficial aquifer system (fine to medium quartz sand in the upper 20-30 m), the 25-35 m thick intermediate aquifer system (in Neogene siliciclastics), and the highly permeable upper Floridan aquifer system in Paleogene to early Neogene limestones. Hydraulic connection between these aquifer systems is indicated by superjacent karst structures throughout the section. Collapse zones of up to 1000 m in diameter and > 50 m depth extend downward from a prominent Middle Miocene unconformity into Oligocene and Upper Eocene limestones. Smaller sinkholes (30-100 m diameter, 10-25 m depth) are present in Middle to Late Neogene clays, sands, and carbonates and extend downward to or below the Middle Miocene unconformity. Filled and open shafts (30-40 m diameter; 10-25 m depth) ring the lake margin and overlie subsurface karst features. The large collapse zones are localized along a northeast-southwest line in the northern ponds and disrupt or deform Neogene to Quaternary strata and at least 50 m of the underlying Paleogene carbonate rocks. The timing and vertical distribution of karst structures are used to formulate a four-stage model that emphasizes stratigraphic and hydrogeologic co-evolution. (1) Fracture-selective shallow karst features formed on Paleogene/early Neogene carbonates. (2) Widespread karstification was limited by deposition of Middle Miocene clays, but vertical karst propagation continued and was focused because of the topographic effects of antecedent karst. (3) Groundwater heads, increase with the deposition of thick sequences of clastics over the semipermeable clays during Middle and Late Neogene time. The higher water table and groundwater heads allowed the accumulation of acidic, organic-rich soils and chemically aggressive waters that percolated down to Paleogene carbonates via localized karst features. (4) After sufficient subsurface dissolution, the Paleogene carbonates collapsed, causing disruption and deformation of overlying strata. The seismic profiles document an episodic, vertically progressive karst that allows localized vertical leakage through the clay-confining units. The spatial and temporal karst distribution is a result of deposition of sediments with different permeabilities during high sea levels and enhanced karst dissolution during low sea levels. Recent decreases in the potentiometric elevation of the Floridan Aquifer System simulates a sea-level lowstand, suggesting that karst dissolution will increase in frequency and magnitude

Environmental problems in gypsum karst terrains., 1996, Andrejchuk Vjacheslav, Klimchouk Alexander
Description of environmental problems in gypsum karst areas, especially of the effects related to human impacts that are unique to gypsum karst systems or most commonly occur herein. The paper deals with pollution (oil, radioactive substances and fertilizers), mining activity, underground water abstraction, construction of dams and reservoirs, collapse and subsidence hazards giving examples of former Soviet Union.

Lecania pusilla, a new bryophilous lichen from the Trieste Karst, 1996, Tretiach M. ,
Lecania pusilla Tretiach sp. nov. is described from the Trieste Karst, where it was collected twice on epilithic mosses in protected overhangs. The new species is characterized by simple or uniseptate spores, pruinose apothecia, and Bacidia-type asci; it has a reduced, granular thallus with no lichen substances. (C) 1996 The British Lichen Society

Radon and its decay products in caves, 1996, Barnes Craig M. , James Julia M. , Whittlestone Stewart

Investigations into radon and its progeny in Australian caves are showing the presence within the caves of high levels of these substances. Described here are the factors that have been shown in studies worldwide to affect the levels of radon and radon decay products over time within cave systems.


Karst aquifer genesis - Modelling approaches and controlling parameters, 1997, Sauter M. , Liedl R. , Clemens T. , Hiickinghaus D.
The quantification of regional groundwater flow and the transport of dissolved substances in a karst system generally poses problems in parameter identification as well as in the modelling of the above processes. On the other hand, available qualitative and quantitative geological information on the history of the development of karst aquifers, which can provide information on the distribution of karstitied horizons within the modelled domain, are generally not considered. A model has been developed, capable of simulating the interactions between the different processes, i.e. flow, transport coupled with carbonate dissolution, taking into account the varying boundary conditions, e.g. changes in geological and geomorphological (base level) and climatic conditions (recharge depth, temperature). A sensitivity analysis of the duration of karstification to changes in climatic parameters and physico-chemical constants of carbonate dissolution shows that the equilibrium concentration of calcium and the initial diameter of the conduits are very dominant factors.

Kinetics and mechanisms of precipitation of calcite as affected by P-CO2 and organic ligands at 25 degrees C, 1998, Lebron I. , Suarez D. L. ,
This study was conducted to develop a model for the precipitation rate of calcite under varying CO2 partial pressures and concentrations of dissolved organic carbon (DOG). Precipitation rates of calcite were measured in solutions with supersaturation values (Omega) between 1 and 20 and in the presence of 2 m(2)L(-1) of calcite. Experiments were run at partial pressures of CO2 (P-CO2) in the range of 0.035-10 kPa and DOC concentrations in the range of 0.02-3.50 mM. The effects of these two variables were quantified separately for the precipitation mechanisms of crystal growth and heterogeneous nucleation. We found an increase in precipitation rate (at constant Omega) when P-CO2 increased. For constant Omega, we also found a linear relationship between calcite precipitation rate and activity of CaHCO3, indicating that CaHCO3 species have an active role in the mechanism of calcite precipitation. These findings suggest that the increase in the precipitation rate with higher P-CO2 levels is likely caused by the increase in the negative charge on the calcite surface together with an increase in the activity of CaHCO3 species in solution. The mechanism of inhibition of calcite crystal growth by organic ligands has been shown to be surface coating of the crystals by DOG. The amount of DOC adsorbed on the surface of the calcite crystals follows a Langmuir isotherm for all the P-CO2 levels studied; however, the amount of DOC necessary to inhibit calcite precipitation increased. With increasing P-CO2, the negative charge on the crystal increases, which affects crystal growth, but also these increases in P-CO2 cause a decrease in the solution pH and increase in the ionic strength for constant Omega. Solution pH and ionic strength affect the structure and degree of dissociation of the organic functional groups, which in turn affects the and DOC concentration on the inhibition of crystal growth and heterogeneous nucleation. The effect of P-CO2 and DOC concentration on the precipitation rate of calcite is expressed in a precipitation rate model which reflects the contributions of crystal growth and heterogeneous nucleation. Copyright (C) 1998 Elsevier Science Ltd

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.


Results 1 to 15 of 33
You probably didn't submit anything to search for