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Featured articles from Cave & Karst Science Journals
Characterization of minothems at Libiola (NW Italy): morphological, mineralogical, and geochemical study, Carbone Cristina; Dinelli Enrico; De Waele Jo
Chemistry and Karst, White, William B.
The karst paradigm: changes, trends and perspectives, Klimchouk, Alexander
Long-term erosion rate measurements in gypsum caves of Sorbas (SE Spain) by the Micro-Erosion Meter method, Sanna, Laura; De Waele, Jo; Calaforra, José Maria; Forti, Paolo
The use of damaged speleothems and in situ fault displacement monitoring to characterise active tectonic structures: an example from Zapadni Cave, Czech Republic , Briestensky, Milos; Stemberk, Josef; Rowberry, Matt D.;
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;
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Your search for crust (Keyword) returned 299 results for the whole karstbase:
Showing 1 to 15 of 299
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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.
The author gives a diagnosis for all eastern Monoslistrinae known today, grouping them in the genus Monolistra and dealing with their geographical distribution. He also gives incomplete descriptions of some forms and also describes the new subgenus Monolistrella for M. velkovrhi Sket, the new species M. (Typhlosphaeroma) matjasici and M. (Microlistra) pretneri and the new subspecies M. (Monolistra) caeca intermedia, M. (Typhlosphaeroma) racovitzai pseudoberica and M. (Typhlosphaeroma) racovitzai conopyge.
Following the first systematic part, in this paper the author describes the biological observations made on these Isopod Crustaceans of underground waters. The different sexual characters of the particular groups and the related differences in the behaviour before copulation are described. During the embryonic and larval development small differences between sub-genus are reported. To the differences in Caecospaeroma (according to Daum) the first and second "mancastadium" and another "postmanca stadium" with pereiopods VII not wholly formed have to be added. The author describes the growth of the different parts of the corps and the extremities, comprising the sexual characters.
Anaspides tasmaniae is recorded from a subterranean habitat for the first time. The only difference noted from surface forms was the smaller amount of pigment present.
Speleothems in the form of stalactites, linear stalactitic growths, flowstone, and crusts, from a hand-dug cave in Northeast Kansas (Sec. 2 NENW, T2S, R22E) are composed of calcite and aragonite. If the estimated age of the cave is correct, i.e., 150 to 200 years old, the stalactites have grown at a maximum rate of 0.20 to 0.15 millimetres per year along their vertical axes. All of the speleothems examined contain about one percent strontium (based on qualitative emission spectrograph analyses). Rate of supply and evaporation of the vadose waters may dictate whether aragonite or calcite is the polymorph that precipitates from the cave waters.
Inventory of the Crustaceans collected in the basin of the Fonatine des Suisses at Dijon. The Copepoda are represented by 5 species: Macrocyclops albidits, Eucyclops serrulatus in two slightly different forms, Eucyclops serrulatus var. mihi, Acanthocyclops venustus, Acanthocyclops vernalis and Acanthocyclops robustus. The coexistence of these two last forms in this very tiny environment makes it probable that we have here to do with two distinct species. A determination key is given for the Genus Acanthocyclops. Amphipoda are represented by Niphargus virei and especially Niphargus kochianus kochianus of which more than 100 samples have been collected. Of this last small species some considerations regarding geography, the laying of eggs, sexual dimorphism and closely related species are also given.
In Europe, Asellus cavaticus Leydig until 1963 was the only species known of a phyletic line that extended from Britain to Austria. Until the works of Racovitza in 1919 all the Asellus of the underground world were reported to this species, first known subterranean Asellus. The taxonomic criteria of Racovitza allowed to determine many subspecies. Later on Chappuis refuses to give names to the different encountered forms. Taking as type forms the individuals of the grotte de Sainte-Reine (Meurthe-et-Moselle), considered very similar to the original type forms, we think to be able to define a new subspecies puteanus for the Asellus of a well in Beaujolais. This form differs from cavaticus f. typ. for the form of the male copulation organ, the male pleopod and the number of spines on the dactlya and pereiopodes. A more detailed description of the subspecies valdensis Chappuis is given based on specimens from a cave of the Plateau of Crmieu (Isre).
From 1897 to 1962, many species have been described as belonging to the genus Stenasellus Dollfus. Among all these the forms from Central Africa and one of Western Africa are not conform to the generic description of Racovitza 1924 obliging us to institute two new genera, Metastenasellus and Parastenasellus. The archaeic Asellota belong to the genus Stenasellus Dollfus, Johannella Monod, Metastenasellus nov.gen. and Parastenasellus nov. gen. are thus grouped in a sub family of Stenasellinae and the relationship between the different groups has still to be explained.
Chromatographic analysis of the yellow organs of the fresh-water Isopod Crustacean Caecosphaeroma burgundum Dollfus revealed, through observation of the chromatograms in ultraviolet light, the occurrence of both absorbing and fluorescent substances. Among the latter, only isoxanthopterin has been identified. The yellow pigment, which probably has a pteridine nucleus, could not be identified as a known compound and will be the object of later investigations.
The discovery, in certain subterranean waters, of "pigmented," brown or black Caecosphaeroma burgundum, led to the systematic study of the action of pigmented substances on these crustaceans. The results of these experiments demonstrate that the colorations thus obtained or observed in nature are due to the agglutination of coloured substances on the surface of the carapace and, in certain cases, to an impregnation of the cuticle itself.
The troglobitic Asellid Asellus lusitanicus Frade (1938) is now known from three caves of the Serra de Aire (Central Portugal). It seems to be a good eyeless species of the "coxalis" group.
Chromatographic analysis of the yellow organs of the fresh-water Isopod Crustacean Caecosphaeroma burgundum Dollfus revealed, through observation of the chromatograms in ultraviolet light, the occurrence of both absorbing and fluorescent substances. Among the latter, only isoxanthopterin has been identified. The yellow pigment, which probably has a pteridine nucleus, could not be identified as a known compound and will be the object of later investigations.
Halite has been found in five caves on the Nullarbor Plain, Western Australia. It occurs as stalactites, stalagmites, crusts, or fibres. The climate of the plain is arid to semi-arid, and the halite is derived from wind-blown salts that accumulate in the soil. The halite forms in the caves under conditions of relatively low humidity (about 70%) and high temperature (about 67°F). Its association with older calcite deposits suggests the climate was once wetter or cooler than at present.
The new subspecies, Niphargus jovanovici burgundus n.subsp., is described from a well at Dijon, France. The principal diagnostic characters are given and a comparison with other known subspecies of N. jovanovici is made. Two groups of subspecies in N. jovanovici are distinguished and some critical remarks on probable affinities of N. jovanovici with other species of Niphargus are made.
Two explorations of the galleries of the Orne-Pauline iron mine at Moyeuvre-Grande (Moselle), made one year apart, resulted in the collection on each occasion of varied and abundant material (5 spp. of peracarid crustaceans and a worm) of aquatic troglobites: 3 spp. of Niphargus, one of which is new to Lorraine (N. kochianus kochianus), 2 spp. of isopods, Asellus cavaticus and Caecosphaeroma burgundum (for which this is the northernmost locality), and finally a local form of Dendrocoelides collini.
Results 1 to 15 of 299
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