MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology


Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/template/toolbar_left.php on line 5
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 bedding cave is see bedding-plane cave.?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms


Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/template/toolbar_right.php on line 7
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 plane (Keyword) returned 221 results for the whole karstbase:
Showing 196 to 210 of 221
Höhlen der Schwäbischen Alb als Pegelschreiber für Flussgeschichte und Tektonik in Südwestdeutschland seit dem Miozän, 2011,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Strasser Marcel

In south western Germany the karstified plateau of the Swabian Alb consisting of Upper Jurassic limestones hosts numerous caves, dolines, and dry valleys. Known strath terraces, conglomerates, volcanoes, and impact craters within the study area already provided important time stamps for former studies reconstructing landscape history. It is widely understood, that spatial distribution of most karst features is closely related to the palaeo-water-table and its discontinuous lowering over time, which in turn is the result of incision and/or uplift. The situation of the Swabian Alb at the northern rim of the Northern Alpine Foreland Basin and east of the Rhine Graben valley is the reason for this uplift. Many caves can be used as gauge for vertical displacement, considering horizontal cave passages as product of a stationary palaeowater-table and vertical sections as result of falling base level. In contrast recent studies deal with a different type of speleogenesis independent of base level. This hypogenic speleogenesis must be discussed for the caves of the Swabian Alb. The recently discovered cave named Laierhöhle near Geislingen/Steige is a typical 3d-maze providing several horizontal levels. Passage pattern and distinctive corrosion features match with morphologies (feeders, rising wall- and ceiling channels, outlets) characteristical for hypogenic speleogenesis. However, artesian situations, hydrothermal water or confined aquifers as critical conditions for hypogenic speleogenesis can not be verified. Other features like horizontal passages, water table markers, key-hole-features, and massive stratified sediment bodies are pointing to an epigenic, water-table related speleogenesis. In this study therefore a mixed model for speleogenesis of Laierhöhle is presented, assuming a strong initial deep-phreatic corrosion along fractures and fissures, followed by intensive widening at the palaeo water-table resulting in the formation of horizontal passages. Correlations between horizontal cave-levels, valley-bottoms, strath-terraces, local conglomerates and other caves lead to new and more precise data on the fluvial history, changing drainage pattern, and the uplift of parts of southwest Germany.

In the course of Examinations of cave sediments spherical metallic particles were detected. These magnetic spherules are ablation-products from meteorites during impact. After fallout and flushing into karstic voids and caves the spherules got archived till today. Spherules within Laierhöhle, Laichinger Tiefenhöhle and Mordloch are supposed to originate from the impact event producing the impact craters Steinheimer Becken and/or the Nördlinger Ries 14.59 Ma ago. Within most of the cave sediments spherules are accompanied by crystals of titano-magnetite, which built during volcanic activity of the Urach-Kirchheim volcanic field. Both spherules and titano-magnetites are proxies for re-deposited Mid Miocene Sediments. In this study I could correlate speleogenetic with dated geomorphic features and thus came to a chronology of events. The Laierhöhle records five episodes of long-term stability of the karst water table covering the time-span from late Middle Miocene until the Pliocene/Pleistocene transition. The first two stable episodes can be dated to the late Middle Miocene and Late Miocene (horizontal levels 1 and 2a). An episode responsible for the formation of level 2b falls within Early Pliocene time. Levels 3a and 3b are spatially well separated but must have formed within a relatively short timespan towards the end of the Pliocene. In the working area, total depth of penetrative karstification was in the order of 120 m. This penetration has been accomplished over a period of approximately 12 Ma resulting in an average uplift rate of 0.01 mm/a.


Coupled Thermo-Hydro-Chemical (THC) Modeling of Hypogene Karst Evolution in a Prototype Mountain Hydrologic System, 2011,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Chaudhuri A. , Rajaram H. , Viswanathan H. S. , Zyvoloski G.

Hypogene karst systems are believed to develop when water flowing upward against the geothermal gradient dissolves limestone as it cools. We present a comprehensive THC model incorporating time-evolving fluid flow, heat transfer, buoyancy effects, multi-component reactive transport and aperture/permeability change to investigate the origin of hypogene karst systems. Our model incorporates the temperature and pressure dependence of the solubility and dissolution kinetics of calcite. It also allows for rigorous representation of temperature-dependent fluid density and its influence on buoyancy forces at various stages of karstification. The model is applied to investigate karstification over geological time scales in a prototype mountain hydrologic system. In this system, a high water table maintained by mountain recharge, drives flow downward through the country rock and upward via a high-permeability fault/fracture. The pressure boundary conditions are maintained constant in time. The fluid flux through the fracture remains nearly constant even though the fracture aperture and permeability increase by dissolution, largely because the permeability of the country rock is not altered significantly due to slower dissolution rates. However, karstification by fracture dissolution is not impeded even though the fluid flux stays nearly constant. Forced and buoyant convection effects arise due to the increased permeability of the evolving fracture system. Since in reality the aperture varies significantly within the fracture plane, the initial fracture aperture is modeled as a heterogeneous random field. In such a heterogeneous aperture field, the water initially flows at a significant rate mainly through preferential flow paths connecting the relatively large aperture zones. Dissolution is more prominent at early time along these flow paths, and the aperture grows faster within these paths. With time, the aperture within small sub-regions of these preferential flow paths grows to a point where the permeability is large enough for the onset of buoyant convection. As a result, a multitude of buoyant convection cells form that take on a two-dimensional (2D) maze-like appearance, which could represent a 2D analog of the three-dimensional (3D) mazework pattern widely thought to be characteristic of hypogene cave systems. Although computational limitations limited us to 2D, we suggest that similar process interactions in a 3D network of fractures and faults could produce a 3D mazework.


Speleogenesis of the Buco dei Vinchi inactive swallow hole (Monte Croara karst sub-area, Bologna, Italy), an outstanding example of antigravitative erosion (or paragenesis) in selenitic gypsum. An outline of the post-antigravitative erosion , 2012,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Pasini, Giancarlo

Inactive swallow hole Buco dei Vinchi developed along a plane dividing selenitic gypsum stratum and an underlying shale interlayer, mostly by antigravitative erosion and by post-antigravitative erosion. It formed through six speleogenetic phases starting from a phreatic phase followed by several antigravitative erosion (= paragenetic) and post-antigravitative erosion phases and vadose phase. During first antigravitative erosion phase, the phreatic protoconduits evolved into small antigravitative conduits with typical cross-section in shape of an inversed U or a bulb. At the end of this phase the small antigravitative conduits converged and merged together in successive stages to form ever-bigger conduits, until – at a certain point – most of them flowed into a single, much wider antigravitative conduit, which later evolved into a composite conduit. Wwe demonstrate that the subhorizontal flat ceilings are not a characteristic feature of the antigravitative passages tout court – as claimed by most authors –, but instead they evolved in caves during periods when the piezometric surface was tangent to the vault of the cave (post-antigravitative erosion phenomenon). Thus these flat ceilings are traces of ‘paleo-piezometric surfaces’; moreover these flat ceilings, being sub-horizontal originally, can provide important information on possible tectonic movements or breakdowns occurred after their formation. The possible ages of the karstic phenomena in the selenitic gypsum near Bologna are discussed. This paper points out that the Buco dei Vinchi and the Cava a Filo swallow holes, presently located in “topographic highs”, were very probably in “topographic lows” at the time of their hydrologic activity, and that this is evidence of a relief inversion started at least 127,000 years ago. Therefore the beginning of the first karstic phenomena in the Bologna karst area is much older than this date. It is explained why the absolute altimetrical lowering of the Monte Croara karst sub-area (with respect to the present sea level) should be of about – 0.39 mm/year.


A new karren feature: hummocky karren, 2012,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Plan Lukas, Renetzeder Christa, Pavuza Rudolf, Krner Wilfried

Karren are small-scale landforms on karst surfaces and many types have been described so far. Here we present an apparently new feature which was found on the Hochschwab karst massive in the Northern Calcareous Alps of Austria. So far only few outcrops each having less than 1 m² within a very restricted area have been found. Morphometric analysis reveals that the karren consist of a randomly distributed, dispersed assemblage of small hummocks and depressions in between. The mean distance between neighbouring hummocks is 4 to 5 cm and the mean height is 0.85 cm. Longitudinal sections are gently sinuous. The occurrences are delimited by thin soil cover with grassy vegetation. The karst features continue below that vegetation cover. Therefore, it is clear that the karren have formed subcutaneously. Corroded fissures where water could infiltrate into the epikarst are absent. The bedrock lithology is Middle Triassic limestone of the Wetterstein Formation in lagoonal facies. Geological structures do not govern the feature. The surface is not a bedding plane and small joints and fractures do not govern the arrangement of the hummocks. Thin section analysis regarding rock texture and dolomite components show that there is no compositional difference between hummocks and depressions. Geochemical analyses show that the limestone is very pure with a very low content of Magnesia. Slightly higher Magnesia contents at the hummock surfaces are significant. The data obtained so far only indicate that some dissolution mechanism but not any rock property governs the irregular array. As there exist no descriptions of comparable features in literature, the name “hummocky karren” is suggested for that type of karren landform.


Krubera (Voronja) Cave, 2012,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Klimchouk, Alexander

At the dawn of the new millennium, in January 2001, Krubera (Voronja) Cave in the Arabika Massif, Western Caucasus, became the deepest known cave in the world, with a depth of 1710 m. Discovering the first cave on the planet deeper that 2000 m had been a long-standing dream of cavers around the world, and this was set in 2001 as an official goal of the Call of the Abyss project of the Ukrainian Speleological Association (Ukr.S.A.), one of the most ambitious and successful exploration project in the history of speleology. In October 2004 this goal was reached, when Krubera Cave was pushed to depth of −2080 m. In subsequent years, the Ukr.S.A. expeditions have explored the cave to a depth of −2,191 m in the main branch, and also explored the second branch in this cave, called Nekujbyshevskaja, to a depth of −1697 m. The Arabika Massif that hosts Krubera Cave has unique geological and paleogeographic preconditions for the development of a cave with exceptionally high vertical range.


Krubera (Voronja) Cave, 2012,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Klimchouk, Alexander

At the dawn of the new millennium, in January 2001, Krubera (Voronja) Cave in the Arabika Massif, Western Caucasus, became the deepest known cave in the world, with a depth of 1710 m. Discovering the first cave on the planet deeper that 2000 m had been a long-standing dream of cavers around the world, and this was set in 2001 as an official goal of the Call of the Abyss project of the Ukrainian Speleological Association (Ukr.S.A.), one of the most ambitious and successful exploration project in the history of speleology. In October 2004 this goal was reached, when Krubera Cave was pushed to depth of −2080 m. In subsequent years, the Ukr.S.A. expeditions have explored the cave to a depth of −2,191 m in the main branch, and also explored the second branch in this cave, called Nekujbyshevskaja, to a depth of −1697 m. The Arabika Massif that hosts Krubera Cave has unique geological and paleogeographic preconditions for the development of a cave with exceptionally high vertical range.


A statistical model of karstic flow conduits, 2012,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Boudinet, P.

A statistical model of karstic flow conduits, based on statistical physics of random walks, is developed. It allows us to compute the mean depth of flow conduits versus the distance from the inlet and versus the dip. It provides results that are in good qualitative agreement with previous results of other authors: the mean depth increases, slowly, with the distance, and it increases, not in a regular fashion, with the dip. The variability of the depth of the conduits, possibly leading to some conduits far from the water table, and the fact that well developed conduits are scarce or not, is linked to the probability of exploitation of the different fractures, the potentially permeable bedding planes, faults and joints in the karstifiable rock. On the basis of this result, we propose that interesting cavities - from the point of view of caving and cave diving - are found only in a small range of those exploitation probabilities. Finally, we emphasize the non-euclidean properties of flow conduits; especially, that many shortest pathways may exist and that a straight line is not usually the shortest pathway that actually develops between inlet and outlet.


Strukturgeologie der Karstformen auf der Schneealpe (Stmk.), 2012,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Bauer H. , Hatzenbichler G. , Plan L. , Decker K.
Schneealpe is a heavily karstified massif located 80 km south of Vienna. As a catchment area of the First Vienna Water Main it is of great importance. In this study caves and dolines at Schneealpe are investigated regarding their geological structures from field measurements as well as from map ana lysis. In the field nine dolines and 20 caves were investigated and 385 fault planes were measured. Additionally, the elongation directions of 226 caves and 210 dolines were analysed from cave maps and a karstmorphological map. Karst morphological data show preferred orientations of caves and dolines, yet the dominant directions of these two do not coincide. The structural data obtained show that the extension of the karst features follows in general well the orientation of the locally dominant fault and joint planes. The other results were partly unexpected: structures at the caves show highly variable orientations which mostly do not seem to be affected by regional fault systems. The orientation of shear planes and fractures, which were measured in dolines, yielded consistent results for the entire plateau of the Schneealpe but differ from the regional fault system. The com parison of structural data from caves and dolines shows a moderate agreement within the area of investigation. Therefore the structures and the preferred orientation of karst features of Schneealpe differ from nearby Hochschwab massif where most structures are influenced by the SEMP-fault system.

Development of a deep karst system within a transpressional structure of the Dolomites in north-east Italy, 2013,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Sauro Francesco, Zampieri Dario, Filipponi Marco

The Piani Eterni karst system is one of the longest and deepest caves of Italy situated in the southern sector of the Dolomiti mountain range. The area where the cave was formed displays peculiar structural settings confined in a tectonic transpressive corridor between two regional thrusts (Belluno and Valsugana). During Miocene uplift of the range the inheritance of Mesozoic structures led to the formation of a deep and wide upward-branching flower (or palm tree) structure cutting the carbonate sequence and exposing the surrounding surface to karst processes after erosion. The relative lowering of the hydrologic base level, due both to the uplift of the area and then to the carving of deep glacial valleys in the Quaternary, allowed the formation of paleo-phreatic conduits at subsequently deeper levels, interconnected by vadose shafts and canyons.

This work gives a detailed tectonic interpretation of the transpressive structure and picks out the tectonic features most favorable to the karst development. A detailed statistical analysis of the distribution and orientation of the karst conduits was performed using 31 km of 3D surveys showing that the development of the cave was strictly guided by a few favorable surfaces of stratigraphic and tectonic origin. These features are known in the literature as inception horizons and tectonic inception features, respectively. Cave levels are usually related to lithologic favorable conditions associated with standings of the paleo-water table. Here we suggest that some tectonic surface geometries could have led to the opening of voids in the active tectonic phase leading to the formation of the original proto-conduit network. Different types of tectonic inception features identified in the cave were described in terms of geometry and kinematics. Tensional fractures, as well as fault plane undulations and flexural slip surfaces between beds, are described as the most favorable tectonic surfaces for the development of the conduits. Finally, we discuss why transpressional settings and related flower structures in soluble rocks can enhance the karst process allowing the formation of huge and deep karst systems.


Surface Roughness of Karst Landscapes, 2013,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Day M. , Chenoweth S.

Surface roughness, also termed landscape, terrain, or topographic roughness in geomorphology, is directly connected to theunevenness of surface elevation values. There are many methods to measure surface roughness mathematically: the ratio ofsurface area and its projection onto a horizontal plane, frequency distributions, fractal analysis, and surface curvature.Recent innovations in remote sensing and geographic information systems have resulted in a renaissance of surfaceroughness in geomorphology as a component of digital terrain modeling. Specific morphometric characterizations of karstterrain roughness have been dogged by issues of data availability and accuracy. The Shuttle Radar Topography Missionsolved many of these problems, providing reliable and accurate elevation data for most of the inhabited world. However,tropical karst landscapes in particular are often heavily forested, obscuring the true surface roughness


Karstification as a Predisposing Factor of Seismically Triggered Landslides: Case Study from the Crimean Mountains (Ukraine): Introduction to the Problem, 2013,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Hradeck J. , Pnek T. , ilhn K. , Smolkov V.

Deep-seated gravitational deformations are significant denudational agents of rock slopes at the margins of karstified plateaus of the Crimean Mountains (CM). The CM evolved during Mesozoic–Cenozoic times as a response to the deformation between the Black Sea domain and East-European platform. The southwestern part of the area is characterized by steep, up to 1000-m-high coastal escarpments consisting of Late Jurassic limestones overlying tuff layers and weak Late Triassic flysch with sporadic small intrusions of Middle Jurassic diorites, gabbros and granites. Steep rock slopes contrast with elevated, highly karstified plateaus situated approximately 500–1300 m a.s.l. The aim of this article is to show long-term evolution of a giant rock slope failure close to the Black Sea coast in the southwestern tip of the CM near Foros Town. The failure evolved in highly anisotropic limestones overlying plastic flysch layers where the main head scarp follows a strike-slip fault. The Foros slope failure is an excellent demonstration of the significance of a preparatory stage in the evolution of large deep-seated slope deformations. Inherited and undisturbed horizontal slickensides on the sub-vertical, inactive fault surface serve as good evidence of significant extensional movement of the surface blocks away from the main headscarp. The studied deformation shows that in a relatively small area tensional (cutting) surfaces can be formed by a great variety of rock discontinuities such as the strike-slip fault, joints and steeply inclined bedding planes. The presence of well-developed, nowadays weathered, speleothems furthermore points to significant karstification that provided additional widening of spaces within rock mass. Gravitational movement destroyed and unroofed several cave systems originally presented at the former edge of a karst plateau. Our findings reveal that large rock slope failures can be added to the factors contributing to the evolution of unroofed caves. Although triggering factors of the activation of individual parts of slope deformations can be determined only hypothetically, lessons learned from widespread landslide activity during and after the 1927 Yalta earthquake and rainfall-driven landslides in the vicinity of Feodosia Town make us consider both seismic loading of slopes and high pore-pressures during heavy winter rainfalls or rapid spring snowmelt to be significant factors. Beside seismic activity, intensive Late Holocene slope processes can be attributed to intensive human activity.

 


HYPOGENIC CAVES OF SICILY (SOUTHERN ITALY), 2013,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Vattano M. Audra P. Benvenuto F. Bigot J. Y. Waele J. D. Galli E. Madonia G. Nobé, Court J. C.

 

First results of a study on hypogenic caves in Sicily are presented. Inactive water-table sulphuric acid caves and 3D maze caves linked to rising of thermal waters rich in H2S were recognized. Cave patterns are guided by structural planes, medium and small scale morphological features are due mainly to condensation-corrosion processes. Calcite and gypsum represent the most common cave minerals. Different types of phosphates linked to the presence of large bat guano deposits were analyzed.


Morphology and geology of an interior layered deposit in the western Tithonium Chasma, Mars, 2013,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Baioni, Davide

This paper describes a morphologic and morphometric survey of a 3.1 km-high, domeshaped upland in western Tithonium Chasma (TC) which coincides with areas containing abundant surface signatures of the sulphate mineral kiersite, as identified by the OMEGA image spectrometer. The morphologic features of the dome were investigated through an integrated analysis of the available Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE), Mars Orbiter Camera, and Context Camera data, while the morphometric characteristics of the structure were measured using a topographic map (25-m contour interval) built from high-resolution stereo camera (HRSC) and Mars Orbiter Laser Altimeter (MOLA) data.
The dome displays surface features that were apparently formed by liquid water probably released from melting ice. These features include karst landforms as well as erosive and depositional landforms. The surface of the dome has few impact craters, which suggests a relatively young age for the dome. Layers in the dome appear laterally continuous and are visibly dipping toward the slopes in some places.
The mineralogical and structural characteristics of the dome suggest that it was emplaced as a diapir, similar to the dome structure located in the eastern part of TC, and to many salt diapirs on Earth.


Morphology and geology of an interior layered deposit in the western Tithonium Chasma, Mars, 2013,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Baioni, Davide

This paper describes a morphologic and morphometric survey of a 3.1 km-high, domeshaped upland in western Tithonium Chasma (TC) which coincides with areas containing abundant surface signatures of the sulphate mineral kiersite, as identified by the OMEGA image spectrometer. The morphologic features of the dome were investigated through an integrated analysis of the available Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE), Mars Orbiter Camera, and Context Camera data, while the morphometric characteristics of the structure were measured using a topographic map (25-m contour interval) built from high-resolution stereo camera (HRSC) and Mars Orbiter Laser Altimeter (MOLA) data.

The dome displays surface features that were apparently formed by liquid water probably released from melting ice. These features include karst landforms as well as erosive and depositional landforms. The surface of the dome has few impact craters, which suggests a relatively young age for the dome. Layers in the dome appear laterally continuous and are visibly dipping toward the slopes in some places.

The mineralogical and structural characteristics of the dome suggest that it was emplaced as a diapir, similar to the dome structure located in the eastern part of TC, and to many salt diapirs on Earth.


DEEP TIME ORIGINS OF SINKHOLE COLLAPSE FAILURES IN SEWAGE LAGOONS IN SOUTHEAST MINNESOTA, 2013,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Alexander Jr. E. C. , Runkel A. C. , Tipping R. G.

Three of the approximately twenty-three municipal wastewater treatment lagoons constructed in the 1970s and 1980s in southeastern Minnesota’s karst region have failed through sinkhole collapse. Those collapses occurred between 1974 and 1992. All three failures occurred at almost exactly the same stratigraphic position. That stratigraphic interval, just above the unconformable contact between the Shakopee and Oneota Formations of the Ordovician Prairie du Chien Group is now recognized as one of the most ubiquitous, regional-scale, karst hydraulic high-transmissivity zones in the Paleozoic hydrostratigraphy of southeastern Minnesota. These karst aquifers have been developing multi-porosity conduit flow systems since the initial deposition of the carbonates about 480 million years ago. The existence of syndepositional interstratal karst unconformities between the Oneota and Shakopee Formations and between the Shakopee and St. Peter Formations, were recognized in the 1800s. About 270 million years ago galena, sphalerite and iron sulfides were deposited in pre-existing solution enlarged joints, bedding planes and caves. The region has been above sea level since the Cretaceous and huge volumes of fresh water have flowed through these rocks. The regional flow systems have changed from east-to-west in the Cenozoic, to north-to-south in or before the Pleistocene. The incision of the Mississippi River and its tributaries has and is profoundly rearranging the ground water flow systems as it varies the regional base levels during glacial cycles. The Pleistocene glacial cycles have removed many of the surficial karst features and buried even more of them under glacial sediments. High erosion rates from row crop agriculture between the us1850s and 1930s filled many of the conduit systems with soil. Over eighty years of soil conservation efforts have significantly reduced the flux of mobilized soil into the conduits. Those conduits are currently flushing much of those stored soils out of their spring outlets. Finally, the increased frequency and intensity of major storm events is reactivating conduit segments that have been clogged and inactive for millions of years.The karst solution voids into which the lagoons collapsed have formed over 480 million years. The recognition and mapping of this major karst zone will allow much more accurate karst hazard maps to be constructed and used in sustainable resource management decisions.


Results 196 to 210 of 221
You probably didn't submit anything to search for