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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. ...

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
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 microbial community (Keyword) returned 13 results for the whole karstbase:
Diverse microbial communities inhabiting ferromanganese deposits in Lechuguilla and Spider Caves, 2003, Northup D. E. , Barns S. M. , Yu L. E. , Spilde M. N. , Schelble R. T. , Dano K. E. , Crossey L. J. , Connolly C. A. , Boston P. J. , Natvig D. O. , Dahm C. N. ,
Lechuguilla Cave is an ancient, deep, oligotrophic subterranean environment that contains an abundance of low-density ferromanganese deposits, the origin of which is uncertain. To assess the possibility that biotic factors may be involved in the production of these deposits and to investigate the nature of the microbial community in these materials, we carried out culture-independent, small subunit ribosomal RNA (SSU rRNA) sequence-based studies from two sites and from manganese and iron enrichment cultures inoculated with ferromanganese deposits from Lechuguilla and Spider Caves. Sequence analysis showed the presence of some organisms whose closest relatives are known iron- and manganese-oxidizing/reducing bacteria, including Hyphomicrobium, Pedomicrobium, Leptospirillum, Stenotrophomonas and Pantoea. The dominant clone types in one site grouped with mesophilic Archaea in both the Crenarchaeota and Euryarchaeota. The second site was dominated almost entirely by lactobacilli. Other clone sequences were most closely related to those of nitrite-oxidizing bacteria, nitrogen-fixing bacteria, actinomycetes and beta- and gamma-Proteobacteria. Geochemical analyses showed a fourfold enrichment of oxidized iron and manganese from bedrock to darkest ferromanganese deposits. These data support our hypothesis that microorganisms may contribute to the formation of manganese and iron oxide-rich deposits and a diverse microbial community is present in these unusual secondary mineral formations

Bacterial dynamics in spring water of alpine karst aquifers indicates the presence of stable autochthonous microbial endokarst communities, 2005, Farnleitner Ah, Wilhartitz I, Ryzinska G, Kirschner Akt, Stadler H, Burtscher Mm, Hornek R, Szewzyk U, Herndl G, Mach Rl,
Spring water of two alpine karst aquifers differing in hydrogeology but of nearby catchments were investigated for their bacterial population dynamics. Dolomite karst aquifer spring 1 (DKAS 1) represents a dolomitic-limestone karst aquifer spring showing high average water residence time and relative constant flow. Limestone karst aquifer spring 2 (LKAS 2) constitutes a typical limestone karst aquifer spring with a dynamic hydrological regime and discharge. Dolomite karst aquifer spring 1 yielded constantly lower cell counts and biomasses (median of 15 x 10(6) cells l(-1) and 0.22 mu g C l(-1)) as the LKAS 2 (median of 63 x 10(6) cells l(-1) and 1.1 mu g C l(-1)) and distribution of morphotypes and mean cell volumes was also different between the considered systems, indicating the influence of hydrogeology on microbial spring water quality. Molecular bacterial V3 16S-rDNA profiles revealed remarkable constancy within each spring water throughout the investigation period. Time course analysis of a flood event in LKAS 2 further supported the trend of the temporal constancy of the microbial community. Except for one case, retrieval of partial and full length 16S rDNA gene sequences from the relative constant DKAS 1 revealed similarities to presently known sequences between 80% to 96%, supporting the discreteness of the microbial populations. The gathered results provide first evidence for the presence of autochthonous microbial endokarst communities (AMEC). Recovery of AMEC may be considered of relevance for the understanding of alpine karst aquifer biogeochemistry and ecology, which is of interest as many alpine and mountainous karst springs are important water resources throughout the world

Dominant Microbial Populations in Limestone-Corroding Stream Biofilms, Frasassi Cave System, Italy, 2006, Macalady Jennifer L. , Lyon Ezra H. , Koffman Bess, Albertson Lindsey K. , Meyer Katja, Galdenzi Sandro, Mariani Sandro,
Waters from an extensive sulfide-rich aquifer emerge in the Frasassi cave system, where they mix with oxygen-rich percolating water and cave air over a large surface area. The actively forming cave complex hosts a microbial community, including conspicuous white biofilms coating surfaces in cave streams, that is isolated from surface sources of C and N. Two distinct biofilm morphologies were observed in the streams over a 4-year period. Bacterial 16S rDNA libraries were constructed from samples of each biofilm type collected from Grotta Sulfurea in 2002. {beta}-, {gamma}-, {delta}-, and {varepsilon}-proteobacteria in sulfur-cycling clades accounted for [≥]75% of clones in both biofilms. Sulfate-reducing and sulfur-disproportionating {delta}-proteobacterial sequences in the clone libraries were abundant and diverse (34% of phylotypes). Biofilm samples of both types were later collected at the same location and at an additional sample site in Ramo Sulfureo and examined, using fluorescence in situ hybridization (FISH). The biomass of all six stream biofilms was dominated by filamentous {gamma}-proteobacteria with Beggiatoa-like and/or Thiothrix-like cells containing abundant sulfur inclusions. The biomass of {varepsilon}-proteobacteria detected using FISH was consistently small, ranging from 0 to less than 15% of the total biomass. Our results suggest that S cycling within the stream biofilms is an important feature of the cave biogeochemistry. Such cycling represents positive biological feedback to sulfuric acid speleogenesis and related processes that create subsurface porosity in carbonate rocks

The impact of host rock geochemistry on bacterial community structure in oligotrophic cave environments, 2007, Barton Hazel A. , Taylor Nicholas M. , Kreate Michael P. , Springer Austin C. , Oehrle Stuart A. And Bertog Janet L.
Despite extremely starved conditions, caves contain surprisingly diverse microbial communities. Our research is geared toward understanding what ecosystems drivers are responsible for this high diversity. To asses the effect of rock fabric and mineralogy, we carried out a comparative geomicrobiology study within Carlsbad Cavern, New Mexico, USA. Samples were collected from two different geologic locations within the cave: WF1 in the Massive Member of the Capitan Formation and sF88 in the calcareous siltstones of the Yates Formation. We examined the organic content at each location using liquid chromatography mass spectroscopy and analyzed microbial community structure using molecular phylogenetic analyses. In order to assess whether microbial activity was leading to changes in the bedrock at each location, the samples were also examined by petrology, X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Our results suggest that on the chemically complex Yates Formation (sF88), the microbial community was significantly more diverse than on the limestone surfaces of the Capitan (WF1), despite a higher total number of cells on the latter. Further, the broader diversity of bacterial species at sF88 reflected a larger range of potential metabolic capabilities, presumably due to opportunities to use ions within the rock as nutrients and for chemolithotrophic energy production. The use of these ions at sF88 is supported by the formation of a corrosion residue, presumably through microbial scavenging activities. Our results suggest that rock fabric and mineralogy may be an important driver of ecosystem function and should be carefully reviewed when carrying out microbial community analysis in cave environments.

The impact of host rock geochemistry on bacterial community structure in oligotrophic cave environments., 2007, Barton Hazel A. , Taylor Nicholas M. , Kreate Michael P. , Springer Austin C. , Oehrle Stuart A, Bertog Janet L.
Despite extremely starved conditions, caves contain surprisingly diverse microbial communities. Our research is geared toward understanding what ecosystems drivers are responsible for this high diversity. To asses the effect of rock fabric and mineralogy, we carried out a comparative geomicrobiology study within Carlsbad Cavern, New Mexico, USA. Samples were collected from two different geologic locations within the cave: WF1 in the Massive Member of the Capitan Formation and sF88 in the calcareous siltstones of the Yates Formation. We examined the organic content at each location using liquid chromatography mass spectroscopy and analyzed microbial community structure using molecular phylogenetic analyses. In order to assess whether microbial activity was leading to changes in the bedrock at each location, the samples were also examined by petrology, X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Our results suggest that on the chemically complex Yates Formation (sF88), the microbial community was significantly more diverse than on the limestone surfaces of the Capitan (WF1), despite a higher total number of cells on the latter. Further, the broader diversity of bacterial species at sF88 reflected a larger range of potential metabolic capabilities, presumably due to opportunities to use ions within the rock as nutrients and for chemolithotrophic energy production. The use of these ions at sF88 is supported by the formation of a corrosion residue, presumably through microbial scavenging activities. Our results suggest that rock fabric and mineralogy may be an important driver of ecosystem function and should be carefully reviewed when carrying out microbial community analysis in cave environments.

The impact of host rock geochemistry on bacterial community structure in oligotrophic cave environments, 2007, Barton H. A. , Taylor N. M. , Kreate M. P. , Springer A. C. , Oehrle S. A. , Bertog J. L.

Despite extremely starved conditions, caves contain surprisingly diverse microbial communities. Our research is geared toward understanding what ecosystems drivers are responsible for this high diversity. To asses the effect of rock fabric and mineralogy, we carried out a comparative geomicrobiology study within Carlsbad Cavern, New Mexico, USA. Samples were collected from two different geologic locations within the cave: WF1 in the Massive Member of the Capitan Formation and sF88 in the calcareous siltstones of the Yates Formation. We examined the organic content at each location using liquid chromatography mass spectroscopy and analyzed microbial community structure using molecular phylogenetic analyses. In order to assess whether microbial activity was leading to changes in the bedrock at each location, the samples were also examined by petrology, X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Our results suggest that on the chemically complex Yates Formation (sF88), the microbial community was significantly more diverse than on the limestone surfaces of the Capitan (WF1), despite a higher total number of cells on the latter. Further, the broader diversity of bacterial species at sF88
reflected a larger range of potential metabolic capabilities, presumably due to opportunities to use ions within the rock as nutrients and for chemolithotrophic energy production. The use of these ions at sF88 is supported by the formation of a corrosion residue, presumably through microbial scavenging activities. Our results suggest that rock fabric and mineralogy may be an important driver of ecosystem function and should be carefully reviewed when carrying out microbial community analysis in cave environments.


Community Structure of Subsurface Biofilms in the Thermal Sulfidic Caves of Acquasanta Terme, Italy, 2010, Jones D. S. , Tobler D. J. , Schaperdoth I. , Mainiero M. , Macalady J. L.

We performed a microbial community analysis of biofilms inhabiting thermal (35 to 50°C) waters more than 60m below the ground surface near Acquasanta Terme, Italy. The groundwater hosting the biofilms has 400 to 830 mkM sulfide, <10 mkM O2, pH of 6.3 to 6.7, and specific conductivity of 8,500 to 10,500 mkS/cm. Based on the results of 16S rRNA gene cloning and fluorescent in situ hybridization (FISH), the biofilms have low species richness, and lithoautotrophic (or possibly mixotrophic) Gamma- and Epsilonproteobacteria are the principle biofilm architects. Deltaproteobacteria sequences retrieved from the biofilms have <90% 16S rRNA similarity to their closest relatives in public databases and may represent novel sulfate-reducing bacteria. The Acquasanta biofilms share few species in common with Frasassi cave biofilms (13°C, 80 km distant) but have a similar community structure, with representatives in the same major clades. The ecological success of Sulfurovumales-group Epsilonproteobacteria in the Acquasanta biofilms is consistent with previous observations of their dominance in sulfidic cave waters with turbulent water flow and high dissolved sulfide/oxygen ratios.


Aqueous Geochemical Evidence of Volcanogenic Karstification: Sistema Zacaton, Mexico, 2011, Gary M. O. , Doctor D. H. , Sharp J. M.

The Sistema Zacatón karst area in northeastern Mexico (Tamaulipas state) is limited to a relatively focused area (20 km2) in a carbonate setting not prone to extensive karstification. The unique features found here are characteristic of hydrothermal karstification processes, represent some of the largest phreatic voids in the world, and are hypothesized to have formed from interaction of a local Pleistocene magmatic event with the regional groundwater system. Aqueous geochemical data collected from five cenotes of Sistema Zacatón between 2000 and 2009 include temperature (spatial, temporal, and depth profiles), geochemical depth profiles, major and trace ion geochemistry, stable and radiogenic isotopes, and dissolved gases. Interpretation of these data indicates four major discoveries: 1) rock-water interaction occurs between groundwater, the limestone matrix, and local volcanic rocks; 2) varying degrees of hydrogeological connection exist among cenotes in the system as observed from geochemical signatures; 3) microbially-mediated geochemical reactions control sulfur and carbon cycling and influence redox geochemistry; and 4) dissolved gases are indicative of a deep volcanic source. Dissolved 87Sr/86Sr isotope ratios (mean 0.70719) are lower than those of the surrounding Cretaceous limestone (0.70730-0.70745), providing evidence of groundwater interaction with volcanic rock, which has a 87Sr/86Sr isotope ratio of 0.7050. Discrete hydraulic barriers between cenotes formed in response to sinkhole formation, hydrothermal travertine precipitation, and shifts in the local water table, creating relatively isolated water bodies. The isolation of the cenotes is reflected in distinct water chemistries among them. This is observed most clearly in the cenote Verde where a water level 4-5 meters lower than the adjacent cenotes is maintained, seasonal water temperature variations occur, thermoclines and chemoclines exist, and the water is oxic at all depths. The surrounding cenotes of El Zacatón, Caracol, and La Pilita show constant water temperatures both in depth profile and in time, have similar water levels, and are almost entirely anoxic. A sulfur (H2S) isotope value of δ34S = -1.8 ‰ (CDT) in deep water of cenote Caracol, contrasted with two lower sulfur isotopic values of sulfide in the water near the surface of the cenote (δ34S = -7 ‰ and -8 ‰ CDT). These δ34S values are characteristic of complex biological sulfur cycling where sulfur oxidation in the photic zone results in oxidation of H2S to colloidal sulfur near the surface in diurnal cycles. This is hypothesized to result from changes in microbial community structure with depth as phototropic, sulfur-oxidizing bacteria become less abundant below 20 m. Unique microbial communities exist in the anoxic, hydrothermal cenotes that strongly mediate sulfur cycling and likely influence mineralization along the walls of these cenotes. Dissolved CO2 gas concentrations ranged from 61-173 mg/L and total dissolved inorganic carbon (DIC) δ13C values measured at cenote surfaces ranged from -10.9 ‰ to -11.8 ‰ (PDB), reflecting mixed sources of carbon from carbonate rock dissolution, biogenic CO2 and possibly dissolved CO2 from volcanic sources. Surface measurements of dissolved helium gas concentrations range from 50 nmol/kg to 213 nmol/kg. These elevated helium concentrations likely indicate existence of a subsurface volcanic source; however, helium isotope data are needed to test this hypothesis. The results of these data reflect a speleogenetic history that is inherently linked to volcanic activity, and support the hypothesis that the extreme karst development of Sistema Zacatón would likely not have progressed without groundwater interaction with the local igneous rocks 


Microbiological Activities in Moonmilk Monitored Using Isothermal Microcalorimetry (Cave of Vers Chez Le Brandt, Neuchatel, Switzerland), 2012, Braissant O. , Binderschedler S. , Daniels A. U. , Verrecchia E. P. , Cailleau G.

 

Studies of the influence of microbial communities on calcium carbonate deposits mostly rely on classical or molecular microbiology, isotopic analyses, and microscopy. Using these techniques, it is difficult to infer microbial activities in such deposits. In this context, we used isothermal microcalorimetry, a sensitive and nondestructive tool, to measure microbial activities associated with moonmilk ex-situ. Upon the addition of diluted LB medium and other carbon sources to fresh moonmilk samples, we estimated the number of colony forming units per gram of moonmilk to be 4.8 3 105 6 0.2 3 105. This number was close to the classical plate counts, but one cannot assume that all active cells producing metabolic heat were culturable. Using a similar approach, we estimated the overall growth rate and generation time of the microbial community associated with the moonmilk upon addition of various carbon sources. The range of apparent growth rates of the chemoheterotrophic microbial community observed was between 0.025 and 0.067 h21 and generation times were between 10 and 27 hours. The highest growth rates were observed for citrate and diluted LB medium, while the highest carbon-source consumption rates were observed for low molecular weight organic acids (oxalate and acetate) and glycerol. Considering the rapid degradation of organic acids, glucose, and other carbon sources observed in the moonmilk, it is obvious that upon addition of nutrients during snow melting or rainfall these communities can have high overall activities comparable to those observed in some soils. Such communities can influence the physico-chemical conditions and participate directly or indirectly to the formation of moonmilk.


Comparative microbial community composition from secondary carbonate (moonmilk) deposits: implications for the Cansiliella servadeii cave hygropetric food web, 2013, Summers Engel A. , Paoletti M. G. , Beggio M. , Dorigo L. , Pamio A. , Gomiero T. , Furlan C. , Brilli M. , Leandro Dreon A. , Bertoni R. , Squartini A.

The microbial diversity of moonmilk, a hydrated calcium carbonate speleothem, was evaluated from two Italian caves to provide context for the food web of highly-specialized troglobitic beetles, Cansiliella spp. (Leptodirinae), with distinctive carbon and nitrogen isotope values indicative of a novel food source. The moonmilk and associated percolating waters had low to no extractable chlorophyll, with an average organic C:N ratio of 9, indicating limited allochthonous input and a significant contribution from microbial biomass. The biomass from moonmilk was estimated to be ~104 micro- and meiofaunal individuals per m2 and ~107 microbial cells/ml. Proteobacteria dominated the 16S rRNA gene sequences retrieved from the moonmilk from both caves. The distribution of other proteobacterial classes and phyla in the moonmilk were statistically similar to each other, even though the two caves are geographically separated from each other. Comparing the moonmilk gene sequences to sequences from previously described environmental clones or cultured strains revealed the uniqueness of the moonmilk habitat, as ~15% of all of the moonmilk sequences were more closely related to each other than to sequences retrieved from any other habitat. However, comparative analyses confirmed that as much as ~34% of the clones sequences were also closely related to environmental clones and cultured strains derived from soil and freshwater habitats, which is likely due to the fact that the putative inoculation source for the moonmilk bacterial communities is from overlying soil and percolating fluids from the surface. Prior to our studies of Cansiliella spp., moonmilk has not been considered a food source for cave animals. Our findings provide unique insight into moonmilk microbial diversity that could reveal the underpinnings of the moonmilk carbon and nitrogen cycle that influences the isotopic composition and the morphological adaptations of the troglobitic beetles associated with the moonmilk.


Microbial communities in a coastal cave: Cova des Pas de Vallgornera (Mallorca, Western Mediterranean), 2014, Busquets A. , Fornós J. J. , Zafra F. , Lalucat J. , Merino A.

As a part of an ongoing project on the role of microbes in the biogeochemistry of Majorcan caves, the species diversity of microbial communities present in cave pools of anchialine waters in the Cova des Pas de Vallgornera (Mallorca, western Mediterranean) is investigated by a culture-dependent method. Two-hundred and forty-eight strains isolated from this characteristic cave environment of the littoral karst are identified by whole-cell-MALDI-TOF mass spectrometry and phylogeneticaly by 16S rRNA gene sequences. Total cell counts and species diversity of the bacterial communities decreas with the distance to the entrance of the cave and to the sea. Strains are mainly identified as members of the Gammaproteobacteria and Actinobacteria. Around 20% of the isolates are able to precipitate carbonates. Calcite is the predominant phase, growing in all the precipitates, although struvite is also found in one Pseudomonas and in one Aspergillus cultures. Differences in crystal characteristics of external shape (habit) and growth are observed according to the bacterial species promoting the precipitates. Bacteria associated with multicolored ferromanganese deposits, present in several parts of the cave, are also studied and are identified as Pseudomonas benzenivorans and Nocardioides luteus. The preponderance of Pseudomonas species and the possible contribution of bacteria in calcite deposition are discussed.


Molecular analyses of microbial abundance and diversity in the water column of anchialine caves in Mallorca, Spain., 2014, Menning D. M. , Boop L. M. , Graham E. D. , Garey J. R.

Water column samples from the island of Mallorca, Spain were collected from one site in Cova des Pas de Vallgornera (Vallgornera) and three sites (Llac Martel, Llac Negre, and Llac de les Delícies) in Coves del Drac (Drac). Vallgornera is located on the southern coast of Mallorca approximately 57 km southwest of Coves del Drac. Drac is Europe's most visited tourist cave, whereas Vallgornera is closed to the public. Water samples were analyzed for water chemistry using spectrophotometric methods, by quantitative PCR for estimated total abundance of microbial communities, and by length heterogeneity PCR for species richness and relative species abundance of Archaea, Bacteria, and microbial eukaryotes. Estimated total abundance was multiplied by relative species abundance to determine the absolute species abundance. All sites were compared to determine spatial distributions of the microbial communities and to determine water column physical and chemical gradients. Water quality and community structure data indicate that both Drac Delícies and Drac Negre have distinct biogeochemical gradients. These sites have communities that are similar to Vallgornera but distinct from Drac Martel, only a few hundred meters away. Drac Martel is accessible to the general public and had the most dissimilar microbial community of all the sites. Similarities among communities at sites in Drac and Vallgornera suggest that these two spatially separated systems are operating under similar ecological constraints.


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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