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

Transport and variability of fecal bacteria in carbonate conglomerate aquifers, , Goeppert N. , Goldscheider N.

Clastic sedimentary rocks are generally considered non-karstifiable and thus less vulnerable to pathogen contamination than karst aquifers. However, dissolution phenomena have been observed in clastic carbonate conglomerates of the Subalpine Molasse zone of the northern Alps and other regions of Europe, indicating karstification and high vulnerability, which is currently not considered for source protection zoning. Therefore, a research program was established at the Hochgrat site (Austria/Germany), as a demonstration that karst-like characteristics, flow behavior and high vulnerability to microbial contamination are possible in this type of aquifer. The study included geomorphologic mapping, comparative multi-tracer tests with fluorescent dyes and bacteria-sized fluorescent microspheres, and analyses of fecal indicator bacteria (FIB) in spring waters during different seasons. Results demonstrate that (i) flow velocities in carbonate conglomerates are similar as in typical karst aquifers, often exceeding 100 m/h; (ii) microbial contaminants are rapidly transported towards springs; and (iii) the magnitude and seasonal pattern of FIB variability depends on the land use in the spring catchment and its altitude. Different ground water protection strategies than currently applied are consequently required in regions formed by karstified carbonatic clastic rocks, taking into account their high degree of heterogeneity and vulnerability.

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GHOST-ROCK KARSTIFICATION IN �ENTRE-DEUX-MERS� (GIRONDE, FRANCE), IMPLICATIONS FOR KARSTOGENESIS AND KARSTIC MORPHOLOGY, , Dubois Caroline, Lans Benjamin, Kaufmann Olivier, Maire Richard, Quinif Yves

The formation of the Oligocene « calcaires à Astéries » in the region of « Entre-deux-Mers » is affected by a karstification with subhorizontal caves that drained rivers from swallow-holes to resurgences. Observations in quarries show that ghost-rock alterites are present. This paper describes the ghost-rocks in the quarry of Piquepoche exploiting the Frontenac stone. We have studied horizontally developed ghost-rocks with vertical extensions still containing the residual alterite. They can be badly consolidated calcarenites up to soft material which has been sampled. Speleogenesis is reviewed in the frame of the mechanical erosion of the alterite of a horizontal ghost-rock followed by an incision by free-flowing waters which form a passage with promontories and potholes. Finally, we show that ceiling anastomoses can form by ghost-rock karstification.

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.

On the Geology of the Western States of North America, 0000, Owen David Dale,

The remarks here submitted will be confined chiefly to that part of the Western States of North America watered by the rivers Ohio, Wabash, Illinois, Rock, Wisconsin, Cumberland and Tennessee, lying between the 35th and 43rd degree of N. latitude and the 81st and 91st of W. longitude. The district includes the states of Illinois, Indiana, Ohio, Kentucky, Tennessee, and the Du Buque and Mineral Point districts of Iowa and Wisconsin. This territory occupies an area of about half a million of square miles, but its geological features are remarkably uniform, belonging, with a few partial exceptions, to the periods of the bituminous coal and carboniferous limestone as found in Europe, and the Silurian rocks as described by Sir R. Murchison; the exceptions are the superficial deposits which occasionally cover up these from view over considerable tracts, and these must either be referred to the age of gigantic mammalia and formations of a much newer date, or belong to a marl and greensand found in the western district of Tennessee, probably a portion of the greensand and other members of the cretaceous group. A general idea of the geological formations of the whole tract may be obtained from the annexed diagram. ... This 250-word extract was created in the absence of an abstract

Agressive action of water on carbonate rocks, gypsum and concrete, 1939, Laptev F. F.

Caves as Rockshelters in Southwestern Asia, 1951, Field, Henry

Basic concepts in the theory of homogeneous liquids in fractured rocks,, 1960, Barenblatt, G. E. , I. P. Zheltov, And I. N. Kochina

Breccia and Pennsylvanian cave filling in Mississippian Saint Louis Limestone, Putnam County, Indiana, 1961, Smith Ned Myron, Sunderman Jack Allen, Melhorn Wilton Newton,

A limestone breccia and several bodies of shale and sandstone in Mississippian St. Louis limestone were discovered in a quarry opened during the summer of 1959 in the SE1/4NW1/4 sec. 15, T.15N., R.4W., Putnam County. A small mass of sandy limestone conglomerate overlay part of the breccia. Nearly all these bodies have been removed in quarrying. The breccia and the shale-sandstone masses appear to have originated from 2 separate geologic processes which occurred at 2 different times. The origin of the breccia is in doubt because not enough critical evidence is available to prove conclusively and single origin. The authors believe, however, that the breccia probably is the product of a submarine rock slump during St. Louis time which was triggered by the tectonic activity that initiated early movements along the Mt. Carmel fault. Other possible origins, such as solution of evaporites accompanied by collapse of overlying rock or formation of caves in a karst terrain followed by roof collapse, are not supported by the evidence observed. The shale-sandstone bodies are believed to be rocks of Pennsylvanian age which were deposited in caverns developed during the Mississippian-Pennsylvanian erosion interval. The limestone conglomerate is probably of the same age as the shale-sandstone bodies

Observations on Caves, Particularly Those Of South Australia - 1862 , 1962, Lane, Edward A.

The historical study of Australian caves and caving areas is fascinating although involving the expenditure of vast amounts of time. Australia's early days are unusually well-documented, but in the case of caves the early history is usually wrapped up in rumour, hearsay and clouded by lack of written record. Most research work means long hours poring over old newspaper files, mine reports, land department records and so on, little of which is catalogued. A small number of exploration journals and scientific studies have extensive material on special cave areas, and of these, the volume by Rev. Julian Edmund Woods, F.G.S., F.R.S.V., F.P.S., etc., and is one of the most interesting. This book gives the ideas and beliefs of 100 years ago concerning the origin, development and bone contents of caves and makes interesting reading in the light of more recent studies of cave origins. Wood's study "Geological Observations in South Australia : Principally in the District South-East of Adelaide" was published in 1862 by Longman, Green, Roberts and Green, London. In a preface dated November 15, 1861, Rev. Woods points out that the book was written while he was serving as a missionary in a 22,000 square mile district, and "without the benefit of reference, museum, library, or scientific men closer than England". Up to the time of writing, almost no scientific or geological work had been done in South Australia and much of the area was completely unexplored. The book, also, contained the first detailed description of caves in the south-east of the state. Father Woods writes about many different types of caves in South Australia, for instance, the "native wells" in the Mt. Gambier/Mt. Shanck area. These are caves, rounded like pipes, and generally leading to water level. Woods points out their likeness to artificial wells. He also writes of sea cliff caves, particularly in the Guichen Bay area, and blow holes caused by the action of the waves on the limestone cliffs. Woods discusses many other types of caves found further inland, particularly bone caves. Father Woods discusses cave origins under two sub-heads: 1. Trap rock caves generally resulting from violent igneous action, and 2. Limestone caves resulting from infiltration of some kind. He is mainly concerned with limestone caves which he sub-divides into (a) crevice caves - caves which have arisen from fissures in the rock and are therefore wedge-shaped crevices, widest at the opening, (b) sea-beach caves, caves which face the seashore and are merely holes that have been worn by the dashing of the sea on the face of the cliff, (c) egress caves, or passages to give egress to subterranean streams, (d) ingress caves, or passages caused by water flowing into the holes of rocks and disappearing underground. These caves would have entrance holes in the ground, opening very wide underneath, and having the appearance of water having entered from above, (e) finally a group of caves which he lists by use as "dens of animals".

Classification of carbonate rocks, 1962, Dunham R. J.

Geomorpholgy of the Dip Cave, Wee Jasper, New South Wales, 1963, Jennings, J. N.

The Dip Cave lies about three miles south of Wee Jasper on the western side of the Goodradigbee valley about 500 yards from the river. The cave underlies the nose of a spur running fairly steeply down from Wee Jasper range west of the valley. Only the terminal part of the spur is of limestone, the rest is of impervious rocks. In fact, shales outcrop along the road immediately above the cave. Below this spur there is a much more gently inclined bench in the limestone, trenched by steep-sided gullies coming down from the two flanks of the spur.

Remarks on the significance of experiences in karst geodynamics., 1964, Renault Philippe

Distinction is made between the experiment which "demonstrates" having an argumentative value; and the experiment which "questions" nature by isolating one factor and by determining the mode of its action. The concept of experiment in geology and in geodynamics and the distinctions between geodynamics and geophysics are discussed. Karstic geodynamics considers the action of fluids; mainly liquids; on a soluble rock. It is a science bordering the different branches of geochemistry, hydrology, the mechanics of rocks, and geophysics. Researches in karstic geodynamics are based upon measurements obtained through field surveys, or upon the utilization of a subterranean laboratory. However, in the laboratory this hardly surpasses the stage of experimental demonstration. A series of simple experiments are enumerated to exemplify the above statement, like the one where the attack of a diluted acid on a soluble rock is utilized, in order to enable us to classify the major problems encountered in karstic corrosion. The last chapter discusses the bicarbonate equilibriums of Ca-CO2. Experiment furnishes the empiric criterion on which scientific theory is founded. Each discipline has its own methodology dependent on the object under study having experimental criteria of different nature. This is particularly true in case of such distant phenomena which no longer have a common ground with human dimensions like space for astronomy or time for geology. In such cases the possibilities of "instrumental" experimentations are very limited. After a brief recollection of the principles of experimental procedure and the history of the experiments attempted by geodynamicians (tectonics, geomorphology, etc.) we will analyze several methods of investigation and by relying exactly on the example of karstic corrosion we shall determine those which have a value for the science of karstology.

Laboratory and field evidence for a vadose origin of foibe (domepits)., 1965, Reams Max W.

Foiba (plural, foibe) is a term derived from the northeastern Italian karst region. The word is here suggested for use in preference to other terms referring to vertical cavities in soluble rocks. Foiba is defined as a cavity in relatively soluble rock which is natural, solutional, tends toward a cylindrical shape, and possesses walls which normally approach verticality. In laboratory experiments, limestone blocks were treated with dilute hydrochloric acid, and cavities resembling foibe were produced. Vertical walls developed only when a less soluble layer capped the limestone block or when the acid source was stationary, allowing acid to drip to the area directly below. Water analyses from foibe in central Kentucky and Missouri indicate that the water has had less residence time in the zone of aeration than other waters percolating through the rocks and entering the caves. In central Kentucky, foibe seem to be developed by migrating underground waterfalls held up by less soluble layers or by water moving directly down joints below less soluble layers. In Missouri, foibe are formed by joint enlargement below chert layers. Those foibe in the ceilings of caves are complicated by the enlargement of the lower part of the joints by cave streams during fluctuating water table conditions. In limestone caves of Kansas, foibe are formed in a similar manner as in Missouri. The foibe of the gypsum caves of Kansas are formed mainly on the sides of steep collapse sinkholes and lack joint control although they form beneath less soluble layers in the gypsum. Dripping water is necessary for the development of vertical walls by solution. Less soluble layers seem to be the unique feature which allows water to drip and pour into foibe. The floors of foibe are formed by less soluble layers or near the water table. If foibe intersect previously formed cave passages, no floors may develop.