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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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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 cross section is 1. vertical section of a geologic profile [16]. 2. a section of a cave passage or a chamber across its width [25].?

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KarstBase a bibliography database in karst and cave science.

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Your search for virginia appalachians (Keyword) returned 2 results for the whole karstbase:
RELATION OF MINERALIZATION TO WALL-ROCK ALTERATION AND BRECCIATION, MASCOT JEFFERSON-CITY MISSISSIPPI-VALLEY-TYPE DISTRICT, TENNESSEE, 1994, Haynes F. M. , Keslr S. E. ,
This study was undertaken to assess the relation of Mississippi Valley-type mineralization to wall-rock alteration and brecciation in the Mascot-Jefferson City district, the largest part of the East Tennessee Mississippi Valley-type ore field. The main question of interest was whether the Mississippi Valley-type-forming brines created or greatly enlarged the breccia system that hosts the ore or whether the breccia system was a preexisting paleoaquifer that simply controlled movement of the mineralizing brines. A secondary, and closely related, question was whether brine-wall rock interaction deposited Mississippi Valley-type ore. The breccia system that hosts the East Tennessee ore field began as karst breccias which formed in the upper part of the Late Cambrian-Early Ordovician Knox Group during Middle Ordovician emergence. Brecciation, which was most common at the paleosurface and in a limestone-rich zone about 200 m below the surface, took place when limestone solution caused collapse of primary dolostone layers. Mississippi Valley-type mineralization, consisting of sphalerite and sparry dolomite, fills interstices in the breccias that formed in the limestone-rich part of the Knox Group. Ore is associated with ''recrystalline dolomite'' that replaced limestone and there is an inverse correlation between the original limestone and sphalerite abundance suggesting that the ore-forming fluids reacted strongly with limestone wall rock, possibly dissolving it where alteration was most intense. The assessment of a relation between alteration and Mississippi Valley-type mineralization was based on 3,533 surface drill holes covering the 110-km2 Mascot-Jefferson City district, each of which provided stratigraphic data and quantified estimates of mineralization intensity and alteration intensity. These data show clearly that as much as 50 percent of the limestone in the mineralized breccia section was lost over enormous areas that extend far beyond significant mineralization. The intensity of this effect clearly decreases downdip (toward the east), away from the probable source of meteoric karst-forming waters. These relations, combined with isotopic analyses and reaction path calculations, suggest that breccia formation and limestone dissolution took place during the original karst breccia formation. In contrast, later Mississippi Valley-type mineralization was associated with replacement of limestone by recrystalline dolomite. The main effect of dolomitization on the chemistry of the Mississippi Valley-type brines, an increase in their Ca/Mg ratio, would not cause sulfide precipitation. Thus, it appears unlikely that Mississippi Valley-type-forming brines created much of their ore-hosting breccias or that water-rock interaction was a major cause of Mississippi Valley-type ore deposition

CYCLOSTRATIGRAPHY OF MIDDLE DEVONIAN CARBONATES OF THE EASTERN GREAT-BASIN, 1995, Elrick M,
Middle Devonian carbonates (250-430 m thick) of the eastern Great Basin were deposited along a low energy, westward-thickening, distally steepened ramp. Four third-order sequences can be correlated across the ramp-to-basin transition and are composed of meter-scale, upward-shallowing carbonate cycles (or parasequences). Peritidal cycles (shallow subtidal facies capped by tidal-flat laminites) constitute 90% of all measured cycles and are present across the entire ramp. The peritidal cycles are regressive- and transgressive-prone (upward-deepening followed by upward-shallowing facies trends). Approximately 80% of the peritidal cycle caps show evidence of prolonged subaerial exposure including sediment-filled dissolution cavities, horizontal to vertical desiccation cracks, rubble and karst breccias, and pedogenic alteration; locally these features are present down to 2 m below the cycle caps. Subtidal cycles (capped by shallow subtidal facies) are present along the middle-outer ramp and ramp margin and indicate incomplete shallowing. submerged subtidal cycles (64% of all subtidal cycles) are composed of deeper subtidal facies overlain by shallow subtidal facies. Exposed subtidal cycles are composed of deeper subtidal facies overlain by shallow subtidal facies that are capped by features indicative of prolonged subaerial exposure (dissolution cavities and brecciation). Average peritidal and subtidal cycle durations are between approximately 50 and 130 k.y. (fourth- to fifth-order). The combined evidence of abundant exposure-capped peritidal and subtidal cycles, transgressive-prone cycles, and subtidal cycles correlative with updip peritidal cycles indicates that the cycles formed in response to fourth- to fifth-order, glacio-eustatic sea-level oscillations. Sea-level oscillations of relatively low magnitude (< 10 m) are suggested by the abundance of peritidal cycles, the lack of widely varying, water-depth-dependent facies within individual cycles, and the presence of noncyclic stratigraphic intervals within intrashelf-basin, slope, and basin facies. Noncyclic intervals represent missed subtidal beats when the seafloor lay too deep to record the effects of the short-term sea-level oscillations. Exposure surfaces at the tops of peritidal and subtidal cycles represent one, or more likely several, missed sea-level oscillations when the platform lay above fluctuating sea level, but the amplitude of fourth- to fifth-order sea-level oscillation(s) were not high enough to flood the ramp. The large number of missed beats (exposure-capped cycles), specifically in Sequences 2 and 4, results in Fischer plots that show poorly developed rising and falling limbs (subdued wave-like patterns); consequently the Fischer plots: are of limited use as a correlation tool for these particular depositional sequences. The abundance of missed beats also explains why Milankovitch-type cycle ratios (similar to 5:1 or similar to 4:1) are not observed and why such ratios would not be expected along many peritidal-cycle-dominated carbonate platforms

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