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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 hanging blade is a blade projecting down from the ceiling [10]. see also blade.?

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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
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Your search for lamination (Keyword) returned 13 results for the whole karstbase:
Laminations or varves? Processes of fine grained sediment deposition in caves, 1977, Bull P. A.

CAYMANITE, A CAVITY-FILLING DEPOSIT IN THE OLIGOCENE MIOCENE BLUFF FORMATION OF THE CAYMAN ISLANDS, 1992, Jones B. ,
Caymanite is a laminated, multicoloured (white, red, black) dolostone that fills or partly fills cavities in the Bluff Formation of the Cayman Islands. The first phase of caymanite formation occurred after deposition, lithification, and karsting of the Oligocene Cayman Member. The second phase of caymanite formation occurred after joints had developed in the Middle Miocene Pedro Castle Member. Caymanite deposition predated dolomitization of the Bluff Formation 2-5 Ma ago. Caymanite is formed of mudstones, wackestone, packstones, and grainstones. Allochems include foraminifera, red algae, gastropods, bivalves, and grains of microcrystalline dolostone. Sedimentary structures include planar laminations, graded bedding, mound-shaped laminations, desiccation cracks, and geopetal fabrics. Original depositional dips ranged from 0 to 60-degrees. Although caymanite originated as a limestone, dolomitization did not destroy the original sedimentary fabrics or structures. The sediments that formed caymanite were derived from shallow offshore lagoons, swamps, and possibly brackish-water ponds. Pigmentation of the red and black laminae can be related to precipitates formed of Mn, Fe, Al, Ni, Ti, P, K, Si, and Ca, which occur in the intercrystalline pores. These elements may have been derived from terra rossa, which occurs on the weathered surface of the Bluff Formation. Caymanite colours were inherited from the original limestone. Stratigraphic and sedimentologic evidence shows that sedimentation was episodic and that the sediment source changed with time. Available evidence suggests that caymanite originated from sediments transported by storms onto a highly permeable karst terrain. The water with its sediment load then drained into the subsurface through joints and fissures. The depth to which these waters penetrated was controlled by the length of the interconnected cavity system. Upon entering cavities, sedimentation was controlled by a complex set of variables

DISLOCATION OF THE EVAPORITIC FORMATIONS UNDER TECTONIC AND DISSOLUTION CONTROLS - THE MODEL OF THE DINANTIAN EVAPORITES FROM VARISCAN AREA (NORTHERN FRANCE AND BELGIUM), 1993, Rouchy J. M. , Groessens E. , Laumondais A. ,
Within the Franco-Belgian segment of the Hercynian orogen, two thick Dinantian anhydritic formations are known, respectively in the Saint-Ghislain (765 m) and Epinoy 1 (904 m) wells. Nevertheless, occurrences of widespread extended breccias and of numerous pseudomorphs of gypsum/anhydrite in stratigraphically equivalent carbonate deposits (boreholes and outcrops), suggest a larger extent of the evaporitic conditions (fig. 1, 2). The present distribution of evaporites is controlled by palaeogeographical differentiation and post-depositional parameters such as tectonics and dissolution. These latter have dissected the deposits formerly present in all the structural units. By using depositional, diagenetic and deformational characters of these formations, the article provides a model for the reconstruction of a dislocated evaporitic basin. This segment of the Hercynian chain is schematically composed of two main units (fig. 1, 3) : (1) the autochthonous or parautochthonous deposits of the Namur synclinorium, (2) the Dinant nappe thrusted northward over the synclinorium of Namur. The major thrust surface is underlined by a complex fault bundle (faille du Midi) seismically recognized over more than 100 km. A complex system of thrust slices occurs at the Hercynian front. Except for local Cretaceous deposits, most of the studied area has been submitted to a long period of denudation since the Permian. Sedimentary, faunistic and geochemical data argue for a marine origin of the brines which have generated the evaporites interbedded with marine limestones. Sedimentary structures. - The thick evaporitic formations are composed of calcium-sulfates without any clear evidence of the former presence of more soluble salts (with the exception of a possible carbonate-sulfate breccia in the upper part of the Saint-Ghislain formation). As in all the deeply buried evaporitic formations, the anhydrite is the main sulfate component which displays all the usual facies : pseudomorphs after gypsum (fig. 4A, B), nodular and mosaic (fig. 4C), laminated. The gypsum was probably an important component during the depositional phase despite the predominant nodular pattern of the anhydrite. Early diagenetic nodular anhydrite may have grown during temporary emersion of the carbonates (sabkha environments), but this mechanism cannot explain the formation of the whole anhydrite. So, most of the anhydrite structures result from burial-controlled gypsum --> anhydrite conversion and from mechanical deformations. Moreover, a complex set of diagenetic processes leads to various authigenic minerals (celestite, fluorite, albite, native sulfur, quartz and fibrous silica) and to multistaged carbonate <> sulfate replacements (calcite and dolomite after sulfate, replacive anhydrite as idiomorphic poeciloblasts, veinlets, domino-like or stairstep monocrystals...). These mineral transformations observed ill boreholes and in outcrops have diversely been controlled during the complex evolution of the series as : depositional and diagenetic pore-fluid composition, pressure and temperature changes with burial, bacterial and thermochemical sulfate reduction, deep circulations favored by mechanical brecciation, mechanical stresses, role of groundwater during exhumation of the series. Deformational structures. - A great variety of deformational structures as rotational elongation, stretching, lamination, isoclinal microfolding, augen-like and mylonitic structures are generated by compressive tectonic stresses (fig. 4D to J). The similarities between tectonic-generated structures and sedimentary (lamination) or diagenetic (pseudo-nodules) features could lead lo misinterpretations. The calcareous interbeds have undergone brittle deformation the style and the importance of which depend of their relative thickness. Stretching, boudins, microfolds and augen structures F, H. I) affect the thin layers while thicker beds may be broken as large fractured blocks dragged within flown anhydrite leading to a mylonitic-like structure (fig, 4G). In such an inhomogeneous formation made of interlayered ductile (anhydrite) and brittle (carbonate) beds, the style and the intensity of the deformation vary with respect to the relative thickness of each of these components. Such deformational features of anhydrite may have an ubiquitous significance and can result either from compressive constraints or geostatic movements (halokinesis). Nevertheless, some data evidence a relation with regional tangential stresses: (1) increase of the deformation toward the bottom of the Saint-Ghislain Formation which is marked by a deep karst suggesting the presence of a mechanical discontinuity used as a drain for dissolving solutions (fig. 3, 4); (2) structural setting (reversed series, internal slidings) of the Epinoy 1 formation under the Midi thrust. However, tectonic stresses also induce flowing deformations which have contributed to cause their present discontinuity. It can be assumed that the evaporites played an active role for the buckling of the regional structure as detachment or gliding layers and more specifically for the genesis of duplex structures. Breccia genesis. - Great breccia horizons are widely distributed in outcrops as well as in the subsurface throughout the greater part of the Dinant and Namur units (fig. 2). The wide distribution of pseudomorphosed sulfates in outcrops and the stratigraphical correlation between breccia and Saint-Ghislain evaporitic masses (fig. 2) suggest that some breccia (although not all) have been originated from collapse after evaporites solution. Although some breccia may result from synsedimentary dissolution, studied occurrences show that most of dissolution processes started after the Hercynian deformation and, in some cases, were active until recently : elements made of lithified and fractured limestones (Llandelies quarries) (fig. 5A), preservation of pseudomorphs of late replacive anhydrite (Yves-Gomezee) (fig. 5B, C), deep karst associated with breccia (Douvrain, Saint Ghislain, Ghlin boreholes) (fig. 3, 4, 5D)). Locally, the final brecciation may have been favored by a mechanical fragmentation which controlled water circulations (fig. 5E). As postulated by De Magnee et al. [19861, the dissolution started mostly after the Permian denudation and continued until now in relation with deep circulations and surface weathering (fig. 6). So, the above-mentioned occurrences of the breccia are logically explained by collapse after dissolution of calcium-sulfates interbeds of significant thickness (the presence of salt is not yet demonstrated), but other Visean breccia may have a different origin (fig. 5F). So, these data prove the extension of thick evaporitic beds in all the structural units including the Dinant nappe, before dissolution and deformation. Implications. - Distribution of Visean evaporites in northern France and Belgium is inherited from a complicated paleogeographic, tectonic and post-tectonic history which has strongly modified their former facies, thicknesses and limits (fig. IA, 6). Diversified environments of deposition controlled by both a palaeogeographical differentiation and water level fluctuations led to the deposition of subaqueous (gypsum) or interstitial (gypsum, anhydrite) crystallization. Nevertheless, most of the anhydrite structures can be interpreted as resulting from burial conversion of gypsum to anhydrite rather than a generalized early diagenesis in sabkha-like conditions. Deformation of anhydrite caused by Hercynian tangential stresses and subsequent flow mechanisms, have completed the destruction of depositional and diagenetic features. The tectonic deformations allow us to consider the role of the evaporites in the Hercynian deformations. The evaporites supplied detachment and gliding planes as suggested for the base of the Saint-Ghislain Formation and demonstrated by the structural setting of Epinoy 1 evaporites in reverse position and in a multi-system of thrust-slices below the Midi overthrust (fig. 7). So, although the area in which evaporation and precipitation took place cannot be exactly delineated in geographic extent, all the data evidence that the isolated thick anhydritic deposits represent relics of more widespread evaporites extending more or less throughout the different structural units of this Hercynian segment (fig. 1B). Their present discontinuity results from the combination of a depositional differentiation, mechanical deformations and/or dissolution

Symposium Abstract: Annual Laminations in Speleothems - Recent Palaeoclimatic interpretations and future prospects, 1997, Baker A. , Barnes W. L. , Genty D. , Mockler N. J.

Co-seismic ruptures and deformations recorded by speleothems in the epicentral zone of the Basel earthquake, 1999, Lemeille Francis, Cushing Marc, Carbon David, Grellet Bertrand, Bitterli Thomas, Flehoc Christine, Innocent Christophe,
The study of growth anomalies of speleothems in a karstic environment can provide potential evidence for palaeoearthquakes. These data are used to study the recurrence times of major earthquakes in areas where evidence for historic seismicity is lacking. A study has been carried out in the epicentral area of the 1356 Basel earthquake (epicentral intensity = VII-VIII, macroseismic magnitude = 6.2). The Battlerloch and Dieboldslochli caves, situated in the area of greatest damage, show growth anomalies of speleothems possibly related to a seismic event (several breaks of speleothems and offsets of the axis of the regrowths). The first U/Th disequilibrum measurements by alpha spectrometry show recent ages (less than several tens of thousands of years and probably historic). 14C dating by AMS of carbonate laminations taken on both sides of the anomalies confirm the evidence of a seismic event around 1300 AD. More accurate darings by U/Th TIMS are carried out in order to compare the information provided by the two different dating methods.ResumeL'etude des anomalies de developpement des speleothemes en milieu endokarstique peut permettre de retrouver la trace de paleoseismes. Ces donnees sont utilisees pour etudier les periodes de retour des seismes majeurs dans les regions ou la sismicite historique n'est pas suffisante. Une etude a ete menee dans la zone epicentrale du seisme de Bale de 1356 (intensite epicentrale = VII-VIII, magnitude macrosismique = 6,2). Dans l'aire de degats majeurs, les grottes du Battierloch et du Dieboldslochli ont montre l'existence d'anomalies de croissance des speleothemes pour lesquelles une origine sismique est possible (nombreuses ruptures de speleothemes et decalage de l'axe de croissance des repousses). Les premieres mesures de desequilibres U/Th par spectrometrie alpha indiquent des ages recents (inferieurs a quelques dizaines de milliers d'annees et probablement historiques). Les datations 14C par AMS de carbonates des lamines preleves de part et d'autre de ces anomalies confirment l'empreinte d'un evenement destructif brutal vers 1300 AD. Des datations plus precises par U/Th TIMS sont en cours de realisation afin de confronter les informations apportees par ces deux chronometres

Cave fill in the Črnotiče Quarry, SW Slovenia: palaeomagnetic, mineralogical and geochemical study, 1999, Bosá, K Pavel, Mihevc Andrej, Pruner Petr, Melka Karel, Venhodová, Daniela, Langrová, Anna

A fossil cave, filled with cave sediments was open in the Črnotiče Quarry. An about 1.75 m high section was analysed. Profile consists of banded carbonate rocks intercalated by red clays which was deposited on corroded/eroded surface of older speleothems. Banded and laminated carbonate rocks are composed of recrystallized calcilutite resemble freshwater limestones. Characteristics of lamination could indicate its origin from organic-rich films. Red clays are composed of quartz, smectite, vermiculite, gibbsite, pM kaolinite, goethite, anatase, rutile, haematite, calcite, micas and feldspar. They contain pellets with Mn hydroxyoxides. That red clays are weathering products redeposited in water-saturated environment. Samples are characterised by intermediate up to high magnetic values of Jn which is caused by the presence of high amount of Fe-minerals. Mean palaeomagnetic directions are for the group of normal palaeomagnetic polarity equal to D = 10.6°; I = 55.0°, and for the group of reverse polarity than D = 173.0°; I = -31.3°. The top part of the profile shows reverse palaeomagnetic direction interrupted by two normal magnetised zones. According to the arrangement of individual magnetozones we assume, that the top of the highest normal polarised magnetozone could be correlated with the Olduvai event (1.76/1.79 Ma) as the youngest possibility, and therefore the rest of profile must be older.


Seasonal variations in Sr, Mg and P in modern speleothems (Grotta di Ernesto, Italy), 2001, Huang Yiming, Fairchild Ian J. , Borsato Andrea, Frisia Silvia, Cassidy Nigel J. , Mcdermott Frank, Hawkesworth Chris J. ,
Sub-annual variations in trace element chemistry and luminescence have recently been demonstrated from speleothems and offer the potential of high-resolution palaeoclimatic proxies. However, no studies have yet examined microscopic trace element variations in relation to modern cave conditions. In this study, the spatial variations in trace element (Sr, Mg and P) concentrations in speleothems (a stalagmite and a soda straw stalactite) from the alpine Ernesto cave (temperature 6.60.1[deg]C) in a forested catchment in NE Italy have been studied using secondary ion mass spectrometry (SIMS) and compared with environmental parameters and waters in the modern cave. An annual lamination exists in the stalagmite and soda straw stalactite in the form of clear calcite with narrow visible layers, which are UV-fluorescent and interpreted to contain soil-derived humic/fulvic acids washed into the cave during autumn rains. Microanalyses were undertaken of seven annual laminae, probably deposited during the 1960s in the stalagmite, and seven laminae in the 1990s for the stalactite.The analysis results show that Sr consistently has a trough and P, a peak centred on the inclusion-rich layer. Mg shows mainly a negative covariation with Sr in laminae formed in the 1990s, but a positive covariation in the stalagmite formed in 1960s. The spatial scale of the main geochemical variations is the same as that of annual laminae of inclusion-poor and inclusion-rich couplets. Mass balance arguments are used to show that the P is inorganic in form and presumably occurs as individual phosphate ions within the calcite.Most drip waters show limited chemical variations, but a summer peak in trace elements in 1995 and a decrease in Mg/Ca in the following winter are notable. More pronounced covariations in Mg/Ca and Sr/Ca are shown by a site with highly variable drip rates where ratios increase at slow drip rates. The strongest seasonal variations are found in pool waters, where ratios increase reflecting significant Ca removal from the water into the calcite during the winter in response to seasonal PCO2 variations in cave air. Thus, the cave waters' compositions tend to reflect climate conditions, such that Mg/Ca and Sr/Ca are tentatively interpreted to be higher when climate conditions are dry.Combining results from the speleothems and cave water along with the behaviour of each trace species, Mg/Ca variations in the speleothems are considered to reflect their variation in the cave waters, whereas, Sr incorporation is also dependent on precipitation rate, in this case, mainly controlled by temporal variations in PCO2 in the cave (and conceivably, also by inhibitors such as phosphate). P adsorption (a fraction of which is subsequently incorporated within calcite) depends on aqueous phosphate concentration and water flux, both of which should increase during the autumn. Therefore, multiple trace element profiles in speleothems reflect multiple aspects of environment seasonality and conditions, and hence, a calibration against weather records is desirable to establish their palaeoclimatological meaning. The strong annual variation of trace elements, and particularly P, can provide chronological markers for high-resolution studies of other climate proxies, such as stable isotopes

Carbonate Speleothems in the Dry, Inneralpine Vinschgau Valley, Northernmost Italy: Witnesses of Changes in Climate and Hydrology Since the Last Glacial Maximum, 2002, Spotl C. , Unterwurzacher M. , Mangini A. , Longstaffe F. J. ,
An interesting association of slope breccia, inactive and active tufa deposits, and speleothems is present in the central Vinschgau Valley, Italy. The occurrence of abundant carbonate cements in fractures and voids of crystalline basement rocks is unexpected considering the fact that this valley is among the driest spots in the entire Alps. Low annual precipitation of 440-530 mm coupled with frequent wind give rise to a semiarid climate and steppe vegetation along the south-facing slopes of the valley. Springs in this area are mostly supersaturated with respect to calcite, and carbonate precipitation occurs locally as tufas and, less well known because of lack of accessibility, as speleothems in the shallow subsurface. The majority of the tufa deposits and speleothems, however, are fossil. Speleothems are composed of low-Mg calcite and calcite-aragonite, respectively. Delicate growth textures including presumable annual lamination caused by pronounced changes in fluorescence intensity are preserved in both calcite and aragonite. Most calcite is a primary precipitate, but small amounts of secondary calcite replacing aragonite are common in most aragonite-bearing samples. The highly radiogenic Sr isotope composition, as well as high concentrations of U, Fe, Sr, and Mg, indicate that the groundwater from which these carbonates precipitated experienced intensive interaction with the host crystalline rocks. The very low tritium concentrations and the lack of a seasonal O isotope variation in modern spring waters, as well as their rather constant hydrochemical composition, also support this suggestion. S isotope data for dissolved sulfate and Ca and Mg sulfate precipitates indicate a sulfide source, i.e., oxidation of sulfide ore minerals in the aquifer, resulting in elevated sulfate and Fe concentrations. Th/U dating of speleothem samples using thermal ionization mass spectrometry yielded ages between 13,710 and 378 yr BP, with most ages falling in the early to middle Holocene. Although no isotopic dates are available for the tufa deposits, field evidence strongly suggests that speleothems, tufa deposits, and carbonate cements in the slope breccia were closely related. We therefore interpret the existence of these terrestrial carbonates as evidence of changes in climate since the middle Holocene. Their presence suggests a higher annual rainfall during the first half of the Holocene, possibly because of enhanced moisture transport from the Mediterranean

REE3 and Mn2 activated cathodoluminescence in lateglacial and Holocene stalagmites of central Europe: evidence for climatic processes?, 2004, Richter Detlev K. , Gotte Thomas, Niggemann Stefan, Wurth Georg,
Combined visual cathodoluminescence (CL) and spectral analyses of CL reveals periodic enrichments of rare earth elements (REE3) and manganese (Mn2) within the laminations of eight calcitic lateglacial to postglacial stalagmites. In the annual layers, the enrichment of trace elements can be correlated with the autumn/winter laminae, which are strongly pigmented and rich in organic carbon. During the Holocene, they occur especially in the Atlantic stage and in subrecent/recent times. The enrichment of REE3 and Mn reflects times of more intense weathering, which presumably prevailed during the Atlantic warm and humid climate. In subrecent/recent times, especially the last 100 years, these enrichments may have been at least partially anthropogenically induced

Les stalagmites du rseau du trou Noir (Gironde) : rle de leffet de site dans lenregistrement du signal climatique et environnemental, 2006, Lans Benjamin , Maire Richard , Ortega Richard , Deves Guillaume , Bacquart Thomas , Plaisir Cyril , Quinif Yves Et Perrette Y.
The speleothems of trou Noir cave (Gironde, France): the role of their situation in registering climatic signals - The trou Noir is an active cave system (sinkhole-resurgence) situated in the Oligocene porous limestone of the plateau of Entre-deux-Mers near Bordeaux (Gironde). Six stalagmites have been sampled for analyzing the environmental evolution controlled by local parameters inside the cave. The studied indicators are calcitic microfabrics, lamination, discontinuities, porosity, organic matter, and radioactivity. Because of a narrow passage located in the middle of the cave, three speleothems upstream have recorded the fluctuations of the underground river during floods, especially detritic sedimentation (clay/calcite alternations), erosion (internal corrosion surface), mechanical shocks (fissures). Downstream, the three other stalagmites have not been flooded; in the small dry passage near the resurgence, two speleothems show, in thin section, many biologic filaments (bacteria or mycelian filaments) because of organic matter (guano from bats). The site is protected (Natura 2000). The trou Noir is an example of a young cave which has recorded the Holocene evolution, particularly the Little Ice Age (detrital/calcitic stalagmite) and the present period.

Influence of depositional setting and sedimentary fabric on mechanical layer evolution in carbonate aquifers, 2006, Graham Wall Brita R. ,
Carbonate aquifers in fold-thrust belt settings often have low-matrix porosity and permeability, and thus groundwater flow pathways depend on high porosity and permeability fracture and fault zones. Methods from sedimentology and structural geology are combined to understand the evolution of fracture controlled flow pathways and determine their spatial distribution. Through this process bed-parallel pressure-solution surfaces (PS1) are identified as a fracture type which influences fragmentation in peritidal and basinal carbonate, and upon shearing provides a major flow pathway in fold-thrust belt carbonate aquifers. Through stratigraphic analysis and fracture mapping, depositional setting is determined to play a critical role in PS1 localization and spacing where peritidal strata have closer spaced and less laterally continuous PS1 than basinal strata. In the peritidal platform facies, units with planar lamination have bed-parallel pressure-solution seams along mudstone laminae. In contrast, burrowed units of peritidal strata have solution seams with irregular and anastamosing geometries. Laminated units with closely spaced bed-parallel solution seams are more fragmented than bioturbated units with anastamosing solution seams. In the deeper-water depositional environment, pelagic settling and turbidity currents are the dominant sedimentation processes, resulting in laterally continuous deposits relative to the peritidal platform environment. To quantify the fracture patterns in the basinal environment, mechanical layer thickness values were measured from regions of low to high bed dip. The results define a trend in which mechanical layer thickness decreases as layer dip increases. A conceptual model is presented that emphasizes the link between sedimentary and structural fabric for the peritidal and basinal environments, where solution seams localize in mud-rich intervals, and the resulting pressure-solution surface geometry is influenced by sedimentary geometry (i.e., stacked fining upward cycles, burrows, planar laminations). In both facies types, laterally continuous PS1 can behave as mechanical layer boundaries. As layer-parallel slip increases to accommodate shear strain in the fold-thrust belt, more PS1 behave as mechanical layer boundaries

Micromorphology of cave sediments, 2013, Karkanas P. , Goldberg P.

Cave sediments are commonly fine grained and lack macroscopic sedimentary structures. Only a detailed analysis of the micromorphological characteristics permits an accurate determination of the sedimentary dynamics of such cave deposits. Microscopic sorting, grading, clast orientation, lamination, intercalation, deformation structures, and porosity are some of the features used to identify microfacies such as lacustrine, slack water, debris flow, slumping, sheet wash, hyperconcentrated flows, and solifluction. In combination with micromorphological data derived from post-depositional diagenetic trend sand anthropogenic evidence, it is possible to reconstruct the evolution of a cave, and the climatic history and landscape volution of the area.


Speleothem and biofilm formation in a granite/dolerite cave, Northern Sweden, 2014, Sallstedt Therese, Ivarsson Magnus, Lundberg Johannes, Sjöberg Rabbe, Vidal Romaní Juan Ramón.

Tjuv-Antes grotta (Tjuv-Ante's Cave) located in northern Sweden is a round-abraded sea cave ('tunnel cave'), about 30 m in length, formed by rock-water abrasion in a dolerite dyke in granite gneiss. Abundant speleothems are restricted to the inner, mafic parts of the cave and absent on granite parts. The speleothems are of two types: cylindrical (coralloid, popcorn-like), and flowstone (thin crusts). Coralloids correspond to terrestrial stromatolite speleothems in which layers of light calcite alternate with dark, silica-rich laminae. The dark laminae are also enriched in carbon and contain incorporated remains of microorganisms. Two types of microbial communities can be distinguished associated with the speleothems: an Actinobacteria-like biofilm and a fungal community. Actinobacteria seem to play an important role in the formation of speleothem while the fungal community acts as both a constructive and a destructive agent. A modern biofilm dominated by Actinobacteria is present in the speleothem-free parts of the dolerite and located in cave ceiling cracks. These biofilms may represent sites of early speleothem formation. Because of its unusual position in between two types of host rock, Tjuv-Ante's Cave represents a unique environment in which to study differences in microbe-rock interactions and speleothem genesis between the granite and dolerite host rock. Our study shows that the mafic rock is superior to the granite in hosting a microbial community and to support formation of speleothems.


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