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 transgression is the spreading of the sea over level areas [16].?

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

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for bauxite (Keyword) returned 51 results for the whole karstbase:
Showing 46 to 51 of 51
Continental France and Belgium during the early Cretaceous: paleoweatherings and paleolandforms, 2006, Thiry Medard, Quesnel Florence, Yans Johan, Wyns Robert, Vergari Anne, Theveniaut Herve, Simoncoincon Regine, Ricordel Caroline, Moreau Marie Gabrielle, Giot Denis, Dupuis Christian, Bruxelles Laurent, Barbarand
During the early Cretaceous, successive tectonic phases and several sea level falls resulted in the emersion of the main part of western Europe and the development of thick 'lateritic' weathering. This long period of continental evolution ended with the Upper Cretaceous transgressions. During this period, the exposed lands displayed a mosaic of diverse morphologies and weathered landscapes. Bauxites are the most spectacular paleoweathering features, known for long in southern France. Recently, new residual outcrops have been identified, trapped in the karstic depressions of the Grands Causses. Other bauxitic formations, containing gibbsite, have also been recognised, occurring with the Clay-with-Jurassic-cherts in the southeastern border of the Paris Basin. These bauxitic formations overlay Jurassic limestone and are buried beneath Upper Cretaceous marine deposits. The recognition of bauxites up north into the southern Paris Basin significantly widens the extension of the Lower Cretaceous bauxitic paleolandscapes. On the Hercynian basements thick kaolinitic weathering mantles occur. They have been classically ascribed to the Tertiary. The first datings of these in situ paleosoils, by means of paleomagnetism and/or radiogenic isotopes, record especially early Cretaceous ages. This is the case for the 'Siderolithic' formations on the edges of the French Massif Central, but also for the kaolinitic profiles in the Belgian Ardennes. In the Flanders, the Brabant basement is deeply kaolinised beneath the Upper Cretaceous cover. These paleosoils show polygenetic evolutions. The relief of these basement paleolandscapes may have been significant. There where probably high scarps (often of tectonic origin) reaching 200 m in elevation or beyond, as well as wide surfaces with inselbergs, as in the present day landscapes of tropical Africa and South America. On the Jurassic limestone platforms occur diverse kaolinitic and ferruginous weathering products. Around the Paris Basin they show various facies, ranging from kaolinitic saprolites to ferricretes. Due to the lack of sedimentary cover, the age of these ferruginous and kaolinitic weathering products has been debated for long, most often allocated to the Siderolithic sensu lato (Eocene-Oligocene). Recent datings by paleomagnetism have enabled to date them (Borne de Fer in eastern Paris Basin) back also to the early Cretaceous (130 {} 10 Ma). These wide limestone plateaus show karstified paleolandforms, such as vast closed and flat depressions broken by conical buttes, but also deep sinkholes in the higher areas of the plateaus and piedmonts. The depth of the karst hollows may be indicative of the range of relative paleoelevations. Dissolution holes display seldom contemporaneous karst fillings, thus implying that the karstland had not a thick weathering cover or that this cover had been stripped off before or by the late Cretaceous transgression. Nevertheless, some areas, especially above chert-bearing Jurassic limestone or marl, show weathering products trapped in the karst features or as a thick weathering mantle. In the Paris Basin, the Wealden gutter looked like a wide floodplain in which fluvio-deltaic sands and clays were deposited and on which paleosoils developed during times of non-deposition. The edges of the gutter were shaped as piedmonts linked up with the upstream basement areas. The rivers flowing down to the plain deposited lobes of coarse fluvial sands and conglomerates. The intensity of the weathering, the thickness of the profiles and their maturation are directly dependent on the duration of the emersion and the topographic location relative to the gutter. Near the axis of the gutter, where emersion was of limited duration, the paleoweathering features are restricted to rubefaction and argillization of the Lower Cretaceous marine formations. On the other hand, on the borders of the basin and on the Hercynian basement, where emersion was of longer duration, the weathering profiles are thicker and more intensively developed. The inventory of the Lower Cretaceous paleoweathering features shows the complexity of the continental history of this period. Moreover, the preserved weathering products are only a part of this long lasting period, all the aspects relative to erosion phases are still more difficult to prove and to quantify. In this domain, apatite fission tracks thermochronology (AFTT) can be helpful to estimate the order of magnitude of denudation. Residual testimonies and subsequent transgressions may enable to estimate relative elevations, but in return, we presently have no reliable tool to estimate absolute paleoelevations. In the work presented here, the inventory enabled to draw a continental paleogeographic map showing the nature of the weathering mantles and the paleolandscape features, just as paleoenvironments and paleobathymetry presently appear on marine paleogeographic maps. For the future, the challenge is to make progress in dating the paleoweathering profiles and especially in the resolution of these datings, in order to correlate precisely the continental records with the different events which trigger them (eustatism, climate, regional and global geodynamics). The final goal will be to build up a stratigraphic scale of the 'continental geodynamic and climatic events' in parallel with 'sequential stratigraphy' in the marine realm

Formes et formations superficielles de la partie ouest du Causse de Sauveterre (Grands Causses, Aveyron et Lozre), 2007, Bruxelles Laurent , Simoncoinon Rgine, Guendon Jeanlouis, Ambert Paul
MORPHOLOGY AND SUPERFICIAL FORMATIONS OF THE WESTERN PART OF THE CAUSSE DE SAUVETERRE (GRANDS CAUSSES, AVEYRON AND LOZ?RE, FRANCE). In 2002, the Natural Regional Park of Grands Causses has coordinated a hydrogeological study of the western part of the Causse de Sauveterre, the northernmost of the Grands Causses. A multidisciplinary approach (geology, geomorphology, geochemistry and hydrology) was used to delineate the catchment area of the main springs and to estimate the vulnerability of karstic aquifers. The Grands Causses are situated in the southern part of the French Massif Central. The landscape is characterised by huge limestone plateaus cut by deep canyons. The morphologic study of the western part of the Causse de Sauveterre (Causse de Massegros and Causse de S?v?rac), combined with analysis of superficial formations, allows us to identify the main steps of landscape evolution. The discovery of bauxite and of many outcrops of Upper Cretaceous sandstone confirm that the Coniacian ingression invaded some paleo-landscapes developed within a long period of continental evolution which was initiated at the end of the Jurassic. During the Tertiary, many residual formations form covers of the limestone plateaus. We can distinguish alterites developed from different formations of the stratigraphic series (clay with cherts from Bajocian, dolomitic sand from Bathonian and Callovian, sandy clays from Cretaceous deposits) from some allochtonous deposits which can be found in some parts of the Causse de Massegros. These formations are found in association with morphological features (shelves, polj?s, fluvio-karstic valleys, sinkholes) and are more or less responsible of their development. Furthermore, some volcanic rocks cut through or even reused some of them. With the deepening of canyons and the base level drop, horizontal morphologies are preserved only where superficial formations are abundant and thick enough to maintain crypto-corrosion. Elsewhere, karst unplugging removes most of the superficial formations, and the karstic evolution tends to show a vertical development of morphologies and caves. Some springs, which benefit from a favourable lithologic, structural and hydrologic context, are more competitive and expand their catchment area at the expense of the other springs. Many superficial features express this dynamism on the plateau and allow us to determine the most sensible areas for water pollution and the most fragile ones for human activities.

Natural and anthropogenic hazards in the karst of Jamaica, 2007, Day Mj,
About two thirds of Jamaica is karst landscape, and karstic hazards affect much of the country and about half of the population, mostly in rural areas. The karst includes extensive areas of dolines and dry valleys, together with poljes and classical tropical tower and cockpit karst. With population and urbanization increases, and as infrastructure is developed, karstic hazards are becoming more prevalent and risks are increasing. One major natural hazard is seasonal drought, which disrupts water supplies, particularly in rural areas where groundwater resources are poorly developed and residents depend on rainwater and springs. Conversely, seasonal flooding, particularly that associated with tropical storms, causes property damage and human death, injury and displacement. Ground surface subsidence and collapse threatens developing infrastructure, dwellings and livestock, but the potential for catastrophic karstic failure of industrial facilities such as dams and retention ponds, including the storage facilities associated with bauxite mining and processing, appears to be relatively limited. Slope failure also occurs, but is not often recognized as a hazard and has not been studied in detail. Human impacts include quarrying, bauxite mining, groundwater abstraction, urbanization, agricultural development and tourism. Groundwater contamination is a serious anthropogenic hazard, particularly associated with the bauxite industry. Less than 10% of the karst area is within protected areas

Upper Cretaceous to Paleogene forbulge unconformity associated with foreland basin evolution (Kras, Matarsko Podolje and Istria; SW Slovenia and NW Croatia), 2007, Otonič, Ar B.

A regional unconformity separates the Cretaceous passive margin shallow-marine carbonate sequence of Adriatic Carbonate Platform from the Upper Cretaceous and/or Paleogene shallow-marine sequences of synorogenic carbonate platform in southwestern Slovenia and Istria (a part of southwestern Slovenia and northwestern Croatia). The unconformity is expressed by irregular paleokarstic surface, locally marked by bauxite deposits. Distinctive subsurface paleokarstic features occur below the surface (e.g. filled phreatic caves, spongework horizons…). The age of the limestones that immediately underlie the unconformity and the extent of the chronostratigraphic gap in southwestern Slovenia and Istria systematically increase from northeast towards southwest, while the age of the overlying limestones decreases in this direction. Similarly, the deposits of synorogenic carbonate platform, pelagic marls and flysch (i.e. underfilled trinity), deposits typical of underfilled peripheral foreland basin, are also diachronous over the area and had been advancing from northeast towards southwest from Campanian to Eocene. Systematic trends of isochrones of the carbonate rocks that immediately under- and overlie the paleokarstic surface, and consequently, of the extent of the chronostratigraphic gap can be explained mainly by the evolution and topography of peripheral foreland bulge (the forebulge). The advancing flexural foreland profile was the result of vertical loading of the foreland lithospheric plate (Adria microplate) by the evolving orogenic wedge. Because of syn- and post-orogenic tectonic processes, and time discrepancy between adjacent foreland basin deposits and tectonic (“orogenic”) phases it is difficult to define the exact tectonic phase responsible for the evolution of the foreland complex. According to position and migration of the subaerially exposed forebulge, distribution of the foreland related macrofacies and orientation of tectonic structures, especially of Dinaric nappes, and Dinaric mountain chain I suggest that the foreland basin complex in western Slovenia and Istria was formed during mesoalpine (“Dinaric”) tectonic phase due to oblique collision between Austroalpine terrane/Tisia microplate and Adria microplate when probably also a segmentation of the foreland plate (Adria microplate) occurred.


Epigene karst system below a regional bauxitic unconformity Origin of the enigmatic red calcite of the Transdanubian Range (TR), Hungary, 2013, Győ, Ri Orsolya, Mindszenty Andrea, Orbn Richrd, Fodor Lszl, Poros Zsfia, Benk Zsolt, Molnr Ferenc

Epigene karst system below a regional bauxitic unconformity Origin of the enigmatic red calcite of the Transdanubian Range (TR), Hungary, 2013, Győ, Ri Orsolya, Mindszenty Andrea, Orbn Richrd, Lszlsfia Fodor, Poros Zsfia, Benk Zsolt, Molnr Ferenc

Results 46 to 51 of 51
You probably didn't submit anything to search for