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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 cumulative production is the sum total of volumetric discharge of a well since production began [16].?

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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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Your search for attenuation (Keyword) returned 23 results for the whole karstbase:
Showing 1 to 15 of 23
Predicting travel times and transport characterization in karst conduits by analyzing tracer-breakthrough curves, , Morales Tomas, De Valderrama Inigo, Uriarte Jesus A. , Antiguedad Inaki, Olazar Martin,
SummaryThis paper analyzes data obtained in 26 tracer tests carried out in 11 karstic connections following solutional conduits in karst aquifers in the Basque Country. These conduits are preferential drainage pathways in these aquifers and so they confer a marked anisotropy and high vulnerability to them. Consequently, their consideration in protection and management studies and projects is a priority.The connections studied cover a wide hydrogeological spectrum (a wide range of sizes, slopes, geomorphic and hydrologic types) and the tests have been carried out at different hydrodynamic states. It is noteworthy that they all follow a similar trend, which has allowed for the development of a statistical approximation for the treatment of the whole information.Relationships have been established involving velocity, solute time of arrival, attenuation of peak concentration and time of passage of tracer cloud. These relationships are a valuable tool for management and supporting decision-making and allow for making estimates in connections in which the information available was scarce. This information is especially useful, given that the complexity of transport in karst conduits gives way to important deviations between real data (empirical observations) and the data obtained by simple approaches based on the Fickian-type diffusion equation

Highway stormwater runoff in karst areas - preliminary results of baseline monitoring and design of a treatment system for a sinkhole in Knoxville, Tennessee, 1999, Stephenson J. B. , Zhou W. F. , Beck B. F. , Green T. S. ,
Groundwater is vulnerable to contamination in karst areas where highway stormwater runoff may flow directly into karst aquifers with little or no natural attenuation and transport highway-derived contaminants rapidly from sinkholes to locations in the aquifer. The primary goal of this investigation is the development and evaluation of practical remedial measures for treating highway runoff draining into sinkholes. Field testing sites are located in Knoxville, TN, and Frederick, MD. This paper presents a summary of preliminary results of baseline monitoring in Knoxville. Quantitative dye tracing and hydrograph analyses have demonstrated that water draining into the I-40/I-640 sinkhole passes through a phreatic conduit and resurges at Holston Spring ca 128 m (420 ft) from the sinkhole. Stormwater quantity has been monitored continuously for more than 1.5 years, and runoff quality has been monitored during a storm event. For most of the contaminants analyzed, peak contaminant loading at Holston Spring lagged behind the peak at the sinkhole by approximately 1 hour. The movement of stormwater from other sinkholes in the drainage basin to Holston Spring is regulated by partial blockage of the conduit-dominated flow system. Urban development of the karst terrane in eastern Knoxville may be responsible for this observed phenomenon. A pilot-scale stormwater runoff treatment system has been designed using peat, sand, and rock to remove contaminants by sedimentation, filtration, and adsorption. (C) 1999 Elsevier Science B.V. All rights reserved

Geophysical surveys over karst recharge features, Illinois, USA, 2001, Carpenter Pj, Ahmed S,
Karst aquifers supply a significant fraction of the world's drinking water. These types of aquifers are also highly susceptible to pollution from the surface with recharge usually occurring through fractures and solution openings at the bedrock surface. Thickness of the protective soil cover, macropores and openings within the soil cover, and the nature of the weathered bedrock surface all influence infiltration. Recharge openings at the bedrock surface, however, are often covered by unconsolidated sediments, resulting in the inadvertent placement of landfills, unregulated dump sites, tailing piles, waste lagoons and septic systems over recharge zones. In these settings surface geophysical surveys, calibrated by a few soil cores, could be employed to identify these recharge openings, and qualitatively assess the protection afforded by the soil cover. In a test of this hypothesis, geophysical measurements accurately predicted the thickness of unconsolidated deposits overlying karstic dolomite at a site about 100 km south of Chicago, Illinois. Zones of elevated electrical conductivity and high ground-penetrating radar (GPR) attenuation within the sediments coincided with subcropping solutionally-enlarged hydraulically active bedrock fractures. These fractures extend to over 12-m depth, as shown by 2-D inverted resistivity sections and soil coring. Anomalous electromagnetic (EM) conductivity and GPR response may be due to higher soil moisture above these enlarged fractures. An epikarstal conduit at 2.5-m depth was directly identified through a GPR survey. These results suggest that surface geophysical surveys are a viable tool for assessing the susceptibility of shallow karst aquifers to contamination

Leg Attenuation and Seasonal Femur Length: Mass Relationships in Cavernicolous Crickets (Orthoptera: Gryllidae and Rhaphidophoridae), 2002, Studier, E. H. , Lavoie, K. H. , Howarth, F. G.
We report here some factors that affect the relationship between hind femur length (HFL) to crop-empty live weight (CELW) and propose a quantitative, non-lethal measurement ratio that has potential as an index of extent of adaptation to a cavernicolous existence in crickets. Curvilinear relationships exist between HFL and CELW for camel crickets (Ceuthophilus stygius) and cave crickets (Hadenoecus subterraneus). The relationships differ significantly between the species and also by gender within both species and, in cave crickets, by season as well. In C. stygius, females of small HFL are slightly lighter, and those of large HFL slightly heavier than males. In H. subterraneus, females have progressively greater CELW than males as HFL increases. In adult H. subterraneus of identical HFLs, CELW is greatest in fall and least in spring, i.e., individuals are most robust in the Fall in these long-lived crickets, probably due to seasonal constraints on surface feeding. An attenuation index of CELW/HFL? yields a ratio that ranks the extent of adaptation to cave life in these two and eight other species of variously adapted cavernicolous and epigean crickets. Lower values of the attenuation index indicate greater adaptation to cavernicolous existence. The three gryllid species from Hawaii Island are closely related and include the blind, obligate cave cricket, Caconemobius varius, and two surface species, the lava flow cricket, Caconemobius fori, and the marine littoral cricket, Caconemobius sandwichensis. The latter two species are nocturnal scavengers on barren rock habitats. The lower CELW/HFL? ratio in lava flow crickets suggest they use caves more frequently for daytime roosts than does the marine littoral species.

Nutrient processing capacity of a constructed wetland in western Ireland, 2002, Healy M. , Cawley A. M. ,
In Ireland, constructed wetland systems are increasingly being used to perform tertiary treatment on municipal waste effluent from small towns and villages located in areas whose receiving waters are deemed sensitive. The bedrock formation in the west of Ireland is primarily karst limestone and where the overburden-soil cover is very shallow, such waters are highly sensitive to pollution sources, as little or no natural attenuation and/or treatment will occur. Constructed wetland technology has been seen to offer a relatively low-cost alternative to the more conventional tertiary treatment technologies, particularly when dealing with low population numbers in small rural communities. This paper examines the waste treatment performance, in terms of nutrient (P and N) reduction, of a recently constructed surface-flow wetland system at Williamstown, County Galway, Ireland. Performance evaluation is based on more than two years of water quality and hydrological monitoring data. The N and P mass balances for the wetland indicate that the average percentage reduction over the two-year study period is 51% for total N and 13% for total P. The primary treatment process in the wetland system for suspended solids (between 84 and 90% reduction), biological oxygen demand (BOD) (on average, 49% reduction), N, and P is the physical settlement of the particulates. However, the formation of algal bloom during the growing season reduces the efficiency of the total P removal

Epikarst storage in a karst aquifer: a conceptual model based on isotopic data, Milandre test site, Switzerland, 2003, Perrin K. , Jeannin P. Y. , Zwahlen F. ,
The Milandre test site is a karst aquifer characterized by diffuse infiltration, a well developed conduit network, and several tributaries feeding an underground river. Field data include discharge rate measurements, stable isotopes, weekly rainfall and spring-water isotope sampling, and detailed isotope sampling during three flood events. Flood sampling was carried out at several tributaries corresponding to conduit flow, vadose flow and seepage flow. Weekly sampling showed a strong buffering of the rainfall isotopic signal at the spring. This attenuation suggests an important mixing reservoir in the system. Flood events showed highly peaking hydraulic responses but buffered rain isotope responses. These results indicate that the soil and epikarst sub-systems have an important storage capacity. A conceptual model of flow and transport in the soil and epikarst zone is proposed: Soil plays an important role in mixing due to the presence of capillary water storage. Consequently dampened concentrations reach the epikarst despite a rapid hydraulic response. The epikarst acts as the storage element and distributes water as either a base flow component or a quick flow component. When recharge exceeds a given threshold, excess infiltrated water bypasses the soil and epikarst and reaches the saturated zone as fresh flow. Based on this model, the significance of phreatic storage is thought to be limited, at least in Milandre test site. Hence the saturated zone is seen mainly as a transmissive zone through its well developed conduit network. (C) 2003 Elsevier B.V. All rights reserved

Paleoseismic phenomena in karst terrains in Bulgaria and Morocco, 2003, Angelova Dora, Belfoul M'hamed Alaeddin, Bouzid Sophia, Filahi Mustapha, Faik Farid

During the recent years there has been a growing interest in recording and investigating the effects of paleoseismic events in surface and underground karst in almost all countries. Karst represents a reliable reference marker for understanding the potential seismicity in regions with instrumentally established low to moderate seismicity. The karst errains in Bulgaria and Morocco occupy considerable areas. The disturbances in surface and underground karst had usually been provoked by catastrophic one-act events or by repeatedly activated movements by earthquakes. The catastrophic seismic events had disturbed the naturally interrelated karst ecosystems and were the reason for rejuvenation, reactivation or attenuation of karst processes. The natural surface and underground relief had been partially or entirely destroyed; a new type of relief had been formed; the geological environment had been disturbed; changes occurred in the flowrate and direction of surface and underground karst water; wetlands of the gravitation type had been formed; natural caves, local grabens, rock-falls and landslides collapsed partially or entirely and terrains were subjected to subsidence and destruction; the ecological balance in urbanized territories had been disturbed. The present work considers the different types of paleoseismic phenomena in the karst terrains in Bulgaria and Morocco. Recommendations are given for the protection of these areas.


A conceptual model of flow and transport in a karst aquifer based on spatial and temporal variations of natural tracers, 2003, Perrin, Jerome

Karst aquifers represent an important groundwater resource world-wide. They are highly vulnerable to contamination due to fast transport through the system and limited attenuation of contaminants. The two main hydrogeological approaches developed for studying flow and transport are: inference of the
system structure from karst spring hydrographs and chemographs; numerical modelling of flow and transport using a theoretical distribution of flow and transport field parameters. These two approaches lack of validation by detailed field measurements and observations. The main objective of this thesis is to “fill the gap” existing between field and model data. Observations of flow and transport parameters at several locations within the system were used to develop a conceptual model. This model was then compared to the existing models.
The main field test site is the Milandre karst aquifer, located in the Swiss tabular Jura. Natural tracers (major ions, oxygen-18, specific conductance) and discharge were measured on the underground river, its main tributaries, percolation waters, and the main spring. These data were collected on a long-term basis in order to assess the spatial variability of the parameters, and on a short time scale (i.e. flood events) in order to investigate the dynamic processes. Complementary sites (Brandt and Grand Bochat) were used for more observations at the base of the epikarst.
The proposed conceptual model considers four sub-systems: the soil zone, the epikarst, the unsaturated zone, and the phreatic zone. Each has its own specificity with respect to flow and transport. The soil zone controls the actual infiltration into the system. It contributes efficiently to groundwater storage. It mixes quickly stored water with fresh infiltrated water. Its thickness determines land-use: thick soils are generally cultivated whereas thin soils are under forested areas. The solutes concentration of soil waters depends on land-use for pollution-related parameters (nitrate, chloride, sulfate, potassium, sodium). Moreover the soil zone is the main source of CO2 which controls the limestone dissolution-related parameters. The epikarst zone contributes largely to groundwater storage. It distributes groundwater into vadose flow through conduits, and base flow through low permeability volumes (LPV) in the unsaturated zone. It is the sub-system where dissolution-related parameters are mostly acquired.
The unsaturated zone is seen as a transmissive zone connecting the epikarst to the horizontal conduit network of the phreatic zone. In case of flood events, some dissolution still occurs in this sub-system.
The phreatic zone is the partly flooded conduit network draining groundwater to the spring. It collects waters issued from the unsaturated zone, mixes the tributaries, and drain the water towards the discharge area. The role of phreatic storage appears to be limited for both hydraulics and transport.
Tributary mixing is a prominent process that shapes spring chemographs during flood events. In steady-state conditions, base flow is mainly sustained by the epikarst reservoir. Tracer concentrations are stable as the chemical equilibrium is already reached in the epikarst. Waters issued from the different tributaries mix in the conduit network, and the spring chemistry is the result of this mixing.
During flood events, transient flow induces non-linear mixing of the tributaries. The respective contributions of the tributaries change throughout the flood, and the spring chemographs vary accordingly. In case of important recharge, waters issued from other sources than the epikarst participate to the flood. First, soil water reaches the phreatic zone. Its characteristics are a dampened isotopic signal, and ionic concentrations differing from those of the epikarst. Second, fresh water directly issued from rainfall, may reach the phreatic zone. Its characteristics are a varying isotopic signal, and diluted ionic concentrations. The mixing components participating to the flood are controlled by the actual infiltration volume (or height). The limestone dissolution process is effective for the fresh and soil components of flow. However mixing processes play a more important role than dissolution for shaping the spring chemographs.
From a practical point of view, the project confirmed the prominent role of the soil zone and the epikarst on the solute transport in karst systems. This was already integrated in karst vulnerability mapping methods recently developed (EPIK, PI, VULK).

http://doc.rero.ch/record/2604/files/these_PerrinJ.pdf


Intrinsic vulnerability assessment of the south-eastern Murge (Apulia, southern Italy), 2004, Marsico A. , Giuliano G. , Pennetta L. , Vurro M. ,
Maps of areas with different vulnerability degrees are an integral part of environmental protection and management policies. It is difficult to assess the intrinsic vulnerability of karst areas since the stage and type of karst structure development and its related underground discharge behaviour are not easy to determine. Therefore, some improvements, which take into account dolines, eaves and superficial lineament arrangement, have been integrated into the SIN-TACS R5 method and applied to a karst area of the southeastern Murge (Apulia, southern Italy). The proposed approach integrates the SINTACS model giving more weight to morphological and structural data; in particular the following parameters have been modified: depth to groundwater, effective infiltration action, unsaturated zone attenuation capacity and soil/overburden attenuation capacity. Effective hydro-geological and impacting situations are also arranged using superficial lineaments and karst density. In order to verify the reliability of the modified procedure, a comparison is made with the original SINTACS R5 index evaluated in the same area. The results of both SINTACS index maps are compared with karst and structural features identified in the area and with groundwater nitrate concentrations recorded in wells. The best fitting SINTACS map is then overlaid by the layout of potential pollution centres providing a complete map of the pollution risk in the area

Variation of karst spring discharge in the recent five decades as an indicator of global climate change: A case study at Shanxi, northern China, 2005, Guo Q. H. , Wang Y. X. , Ma T. , Li L. X. ,
Karst in Shanxi Province is representative of that in northern China, and karst water systems discharge in the form of springs that are among the most important sources for local water supply. Since the 1950s, attenuation has been the major trend of discharge variation of most karst springs at Shanxi. Based on the case study of 7 karst springs including Niangziguan, Xin'an, Guozhuang, Shentou, Jinci, Lancun, and Hongshan springs, the discharge variation process of karst springs was divided into natural fluctuation phase and anthropogenic impact phase. Discharge attenuation of the 7 karst springs was controlled mainly by climate and human activities, with their contributions being respectively about 60% and 40%. According to the difference of the effect of climate and human activities for each spring, attenuation modes of spring discharge fall into three types: natural process dominated attenuation type, exploitation induced process dominated attenuation type, and mixed attenuation type. The total restored discharge variation of 7 karst springs matched well with the global air temperature change in 1956-2000, clearly indicating the trend of global warming and aridity in the last several decades, and the analysis of discharge variation processes of karst springs can be used as a new tool for global change studies

2D and 3D GPR imaging of sinkholes and dissolution features in Jandaíra karst of Fazenda Belém oil field, Potiguar Basin-CE, northeast of Brazil, PhD Thesis, 2005, Xavier Neto, Pedro

In Fazenda Belém oil field (Potiguar Basin, Ceará State, northeast Brazil) occur frequently sinkholes and sudden terrain collapses associated to an unconsolidated sedimentary cap covering the Jandaíra karst. This research was carried out in order to understand the mechanisms of generation of these collapses. The main tool used was Ground Penetrating Radar (GPR). This work is developed twofold: one aspect concerns methodology improvements in GPR data processing whilst another aspect concerns the geological study of the Jandaíra karst. This second aspect was strongly supported both by the analysis of outcropping karst structures (in another regions of Potiguar Basin) and by the interpretation of radargrams from the subsurface karst in Fazenda Belém.


It was designed and tested an adequate flux to process GPR data which was adapted from an usual flux to process seismic data. The changes were introduced to take into account important differences between GPR and Reflection Seismic methods, in particular: poor coupling between source and ground, mixed phase of the wavelet, low signal-to-noise ratio, monochannel acquisition, and high influence of wave propagation effects, notably dispersion. High frequency components of the GPR pulse suffer more pronounced effects of attenuation than low frequency components resulting in resolution losses in radargrams. In Fazenda Belém, there is a stronger need of an suitable flux to process GPR data because both the presence of a very high level of aerial events and the complexity of the imaged subsurface karst structures. The key point of the processing flux was an improvement in the correction of the attenuation effects on the GPR pulse based on their influence on the amplitude and phase spectra of GPR signals. In low and moderate losses dielectric media the propagated signal suffers significant changes only in its amplitude spectrum; that is, the phase spectrum of the propagated signal remains practically unaltered for the usual travel time ranges. Based on this fact, it is shown using real data that the judicious application of the well known tools of time gain and spectral balancing can efficiently correct the attenuation effects. The proposed approach can be applied in heterogeneous media and it does not require the precise knowledge of the attenuation parameters of the media. As an additional benefit, the judicious application of spectral balancing promotes a partial deconvolution of the data without changing its phase. In other words, the spectral balancing acts in a similar way to a zero phase deconvolution. In GPR data the resolution increase obtained with spectral balancing is greater than those obtained with spike and predictive deconvolutions.


The evolution of the Jandaíra karst in Potiguar Basin is associated to at least three events of subaerial exposition of the carbonatic plataform during the Turonian, Santonian, and Campanian. In Fazenda Belém region, during the mid Miocene, the Jandaíra karst was covered by continental siliciclastic sediments. These sediments partially filled the void space associated to the dissolution structures and fractures. Therefore, the development of the karst in this region was attenuated in comparison to other places in Potiguar Basin where this karst is exposed. In Fazenda Belém, the generation of sinkholes and terrain collapses are controlled mainly by: (i) the presence of an unconsolidated sedimentary cap which is thick enough to cover completely the karst but with sediment volume lower than the available space associated to the dissolution structures in the karst; (ii) the existence of important structural of SW-NE and NW-SE alignments which promote a localized increase in the hydraulic connectivity allowing the channeling of underground water, thus facilitating the carbonatic dissolution; and (iii) the existence of a hydraulic barrier to the groundwater flow, associated to the Açu-4 Unity.


The terrain collapse mechanisms in Fazenda Belém occur according to the following temporal evolution. The meteoric water infiltrates through the unconsolidated sedimentary cap and promotes its remobilization to the void space associated with the dissolution structures in Jandaíra Formation. This remobilization is initiated at the base of the sedimentary cap where the flow increases its abrasion due to a change from laminar to turbulent flow regime when the underground water flow reaches the open karst structures. The remobilized sediments progressively fill from bottom to top the void karst space. So, the void space is continuously migrated upwards ultimately reaching the surface and causing the sudden observed terrain collapses. This phenomenon is particularly active during the raining season, when the water table – that normally is located in the karst – may be temporarily located in the unconsolidated sedimentary cap.


Sedimentary manganese metallogenesis in response to the evolution of the Earth system, 2006, Roy Supriya,
The concentration of manganese in solution and its precipitation in inorganic systems are primarily redox-controlled, guided by several Earth processes most of which were tectonically induced. The Early Archean atmosphere-hydrosphere system was extremely O2-deficient. Thus, the very high mantle heat flux producing superplumes, severe outgassing and high-temperature hydrothermal activity introduced substantial Mn2 in anoxic oceans but prevented its precipitation. During the Late Archean, centered at ca. 2.75[no-break space]Ga, the introduction of Photosystem II and decrease of the oxygen sinks led to a limited buildup of surface O2-content locally, initiating modest deposition of manganese in shallow basin-margin oxygenated niches (e.g., deposits in India and Brazil). Rapid burial of organic matter, decline of reduced gases from a progressively oxygenated mantle and a net increase in photosynthetic oxygen marked the Archean-Proterozoic transition. Concurrently, a massive drawdown of atmospheric CO2 owing to increased weathering rates on the tectonically expanded freeboard of the assembled supercontinents caused Paleoproterozoic glaciations (2.45-2.22[no-break space]Ga). The spectacular sedimentary manganese deposits (at ca. 2.4[no-break space]Ga) of Transvaal Supergroup, South Africa, were formed by oxidation of hydrothermally derived Mn2 transferred from a stratified ocean to the continental shelf by transgression. Episodes of increased burial rate of organic matter during ca. 2.4 and 2.06[no-break space]Ga are correlatable to ocean stratification and further rise of oxygen in the atmosphere. Black shale-hosted Mn carbonate deposits in the Birimian sequence (ca. 2.3-2.0[no-break space]Ga), West Africa, its equivalents in South America and those in the Francevillian sequence (ca. 2.2-2.1[no-break space]Ga), Gabon are correlatable to this period. Tectonically forced doming-up, attenuation and substantial increase in freeboard areas prompted increased silicate weathering and atmospheric CO2 drawdown causing glaciation on the Neoproterozoic Rodinia supercontinent. Tectonic rifting and mantle outgassing led to deglaciation. Dissolved Mn2 and Fe2 concentrated earlier in highly saline stagnant seawater below the ice cover were exported to shallow shelves by transgression during deglaciation. During the Sturtian glacial-interglacial event (ca. 750-700[no-break space]Ma), interstratified Mn oxide and BIF deposits of Damara sequence, Namibia, was formed. The Varangian ([identical to] Marinoan; ca. 600[no-break space]Ma) cryogenic event produced Mn oxide and BIF deposits at Urucum, Jacadigo Group, Brazil. The Datangpo interglacial sequence, South China (Liantuo-Nantuo [identical to] Varangian event) contains black shale-hosted Mn carbonate deposits. The Early Paleozoic witnessed several glacioeustatic sea level changes producing small Mn carbonate deposits of Tiantaishan (Early Cambrian) and Taojiang (Mid-Ordovician) in black shale sequences, China, and the major Mn oxide-carbonate deposits of Karadzhal-type, Central Kazakhstan (Late Devonian). The Mesozoic period of intense plate movements and volcanism produced greenhouse climate and stratified oceans. During the Early Jurassic OAE, organic-rich sediments host many Mn carbonate deposits in Europe (e.g., Urkut, Hungary) in black shale sequences. The Late Jurassic giant Mn Carbonate deposit at Molango, Mexico, was also genetically related to sea level change. Mn carbonates were always derived from Mn oxyhydroxides during early diagenesis. Large Mn oxide deposits of Cretaceous age at Groote Eylandt, Australia and Imini-Tasdremt, Morocco, were also formed during transgression-regression in greenhouse climate. The Early Oligocene giant Mn oxide-carbonate deposit of Chiatura (Georgia) and Nikopol (Ukraine) were developed in a similar situation. Thereafter, manganese sedimentation was entirely shifted to the deep seafloor and since ca. 15[no-break space]Ma B.P. was climatically controlled (glaciation-deglaciation) assisted by oxygenated polar bottom currents (AABW, NADW). The changes in climate and the sea level were mainly tectonically forced

Karstic behaviour of groundwater in the English Chalk, 2006, Maurice L. D. , Atkinson T. C. , Barker J. A. , Bloomfield J. P. , Farrant A. R. , Williams A. T. ,
SummaryAlthough the Chalk is only weakly karstified, tracer testing from stream sinks has demonstrated groundwater flow velocities comparable to those observed in highly karstic aquifers. Field survey of surface karst features in the catchments of the Pang and Lambourn rivers in southern England demonstrates the importance of overlying and adjacent Palaeogene strata in the development of karst features. Tracer techniques employed within the catchments enable further characterisation of the range and connectivity of solutional voids in this area of the Chalk, and allow assessment of the relative importance of different mechanisms of contaminant attenuation. Quantitative tracer test results suggest that groundwater flow may be through a complex combination of small conduits, typically 10-1000 mm in diameter, and more laterally extensive fissures with apertures of 1-50 mm. Evidence of connectivity between conduits and fissures suggest that in areas of the Chalk with rapid groundwater flow, fissures supplying abstraction boreholes may be connected to karst conduit networks with low potential for contaminant attenuation

Rapid karstic bypass flow in the unsaturated zone of the Yorkshire chalk aquifer and implications for contaminant transport, 2007, Allshorn Sjl, Bottrell Sh, West Lj, Odling Ne,
Tracer tests have been performed on the unsaturated zone of the East Yorkshire chalk aquifer, UK. Rapid tracer travel times through significant thicknesses of unsaturated chalk (15-38 m) indicate that bypass flow must occur through fractures. Transport processes in the unsaturated zone of the chalk aquifer thus have similarities to those in the vadose zone of more typically karstic limestone aquifers. Modelling of tracer breakthrough curves indicates that bypass flow is sufficiently rapid to significantly inhibit diffusional loss of tracer into the porous matrix of the chalk. The presence of rapid karstic bypass flow in the unsaturated zone of the chalk will limit the potential for attenuation of groundwater contaminants in this zone

GROUNDWATER VULNERABILITY OF THE KARST - FISSURE HYDROGEOLOGICAL STRUCTURE OF SOUTH -FACING SLOPES OF THE NIZKE TATRY MTS., SLOVAKIA, 2007, KovÃ, Č, OvÃ, E. , MalÃ, K P.

An “intrinsic vulnerability” (according to Zwahlen et al., 2004) to any contamination in general is considered using Malík´s extension (2005) of the Kullman´s method (2000), based on the assessment of the degree the rock disruption and karstifica­tion, affecting the shape of spring discharge recession curves. It is based on the presumption that the intensity of natural con­tamination attenuation processes depends on rock disruption/karstification. The method is applied on the Mesozoic rock en­vironment of the most important hydrogeological structure in the southern slopes of the Nízke Tatry Mountains. Hydrograph analyses of groundwater depletion in the gauged or exploited springs were used for assessment of groundwater vulnerability to human and/or natural pollution. Differences in character of individual depletion hydrographs enable assessment an extent of absorption and elimination processes during the groundwa­ter penetration through the rock environment from the infiltra­tion area to the outflow in the spring or exploited source. The depletion hydrographs reflect not only the character (effect) of outflow area but reflect the effects whole infiltration and accu­mulation area. In total, 68 individual recession curves from 9 gauged springs were analysed. Obtained degrees of groundwater vulnerability are evaluated by 10 degree range of the Kullman´s vulnerability scheme, adjusted by Malík. The reached vulner­ability values are consequently applied and assigned to the lith­ological types of discharge area of gauged springs. This study also describes an existence of individual laminar and turbulent sub-regimes that occur in the karts-fissure rock environment, the type of rock disruption from open micro– to macro fissures - to karst channels and subsequent estimation of the karstifica­tion degree.


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