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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. ...

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 seepage surface is the outflow surface between water level and the intersection of the phreatic surface in a well [16].?

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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;
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Your search for burial (Keyword) returned 103 results for the whole karstbase:
Showing 91 to 103 of 103
Carbonate porosity creation by mesogenetic dissolution: Reality or illusion?, 2012, Ehrenberg Stephen N. , Walderhaug Olav, Bjorlykke Knut

Many authors have proposed that significant volumes of porosity are created by deep-burial dissolution in carbonate reservoirs. We argue, however, that this model is unsupported by empirical data and violates important chemical constraints on mass transport. Because of the ubiquitous presence and rapid kinetics of dissolution of carbonate minerals, the mesogenetic pore waters in sedimentary basins can be expected to be always saturated and buffered by carbonates, providing little opportunity for the preservation of significantly undersaturated water chemistry during upward flow, even if the initial generation of such undersaturated pore water could occur. A review of the literature where this model has been advanced reveals a consistent lack of quantitative treatment. In consequence, the presumption of mesogenetic dissolution producing a net increase in secondary porosity should not be used in the prediction of carbonate reservoir quality. 


Multilevel Caves and Landscape Evolution, 2012, Anthony, Darlene M.

Multilevel caves are formed by periods of water table stability punctuated by changes in the position of the water table. These cave systems are hydrologically linked to regional rivers and can be used to date episodes of river stability and incision. The measurement of cosmogenic radioisotopes in cave sediments yields a burial age for the sediment, which in turn equates to the time of passage abandonment due to water-table lowering. Karst geomorphologists and others are using burial dates from multilevel caves to calculate Plio-Pleistocene rates of river incision, tectonic uplift, and erosion in various parts of the world.


Landscape evolution in the Tacchi area (Central-East Sardinia, Italy) based on karst and fluvial morphology and age of cave sediments, 2012, De Waele, J. , Ferrarese F. , Granger, D. Sauro, F.

 

The east-central part of Sardinia (Italy) is characterised by Jurassic
dolomitic mesas (Tacchi, or «table mountains») that overlie a Palaeozoic
basement mainly composed of metavolcanics and phyllites. These mountains
are the remnants of a continuous carbonate cover, dissected by
faults and river erosion, and are now completely isolated hydrological
systems. Most of these rivers have cut valleys more than 200 metres deep
into the Palaeozoic basement rocks, whose slopes are often characterised
by landslides, suggesting their recent oversteepening. Some valleys, on
the contrary, have not reached the base of the carbonate sequence and
appear to be suspended above the deeper incisions, apparently disconnected
by them. Several subhorizontal surfaces can be distinguished on
the table mountains, related to local base level stillstands. Also water
table caves, scattered along the flanks of the mountains over an altitudinal
range of about 200 m, show several stillstands in base level lowering.
 
26Al and 10Be burial dating of sediments in four caves located at different
elevations on the flanks of the suspended Taquisara Valley show
an Upper Pliocene or Lower Pleistocene age. Thus, this valley appears to
be of Late Tertiary age. The deeper valleys, such as Riu Pardu, that dissect
the Tacchi mountains completely, cutting deeply into the basement
rocks, are much younger, as their unstable slopes suggest. Knickpoint retreat
in Riu Pardu and estimated valley erosion rates suggest the capture
of Riu Pardu by Rio Pelau to have occurred in the last 100 ky.

Preservation and burial of ancient karst., 2013, Osborne, R. A. L.

Ancient karst features can be preserved by burial, filling, or by occurring in areas with extremely slow denudation. Although the terms ‘paleokarst’, ‘relict karst’,‘buried karst’, and ‘fossil karst’ have caused much confusion, paleokarst, buried karst, and relict karst can be defined in terms useful to karst geomorphologists and cave scientists. The term ‘fossil karst’ is best abandoned. Burial and paleokarstification are not necessarily the end of karst. Ancient features may be exhumed and reactivated. Karst ends with denudation at the Earth’s surface. Unroofed caves are a particular feature of karst denudation. Most ancient karst features may be preserved by filling, burial, and exhumation. In unusual conditions, karst features have survived at the surface since the Mesozoic. Burial, exhumation, and slow denudation may not be sufficient for extreme survival; relative vertical movement may be required. As caves and many other karst landforms are negative features, they are prone to filling by a range of materials, making cave sediments and paleokarst deposits quite diverse. Whole karst landscapes can be buried and evidence of burial can be recorded in the diagenesis of sediments. Although filled and unfilled caves can survive shallow burial, deep burial can crush caves, forming crackle breccia. Exhumation can occur from the surface following uplift or from below following hypogene speleogenesis. Preservation, burial, and exhumation of ancient karst have two unexpected consequences. Caves can be older than the landscapes in which they occur and stalagmites can be the longest surviving karst features


Evolution of Intrastratal Karst and Caves in Gypsum, 2013, Klimchouk, A. B.

The term ‘intrastratal karst’ denotes a series of evolutionary karst types corresponding to successive stages of karst developmentin a soluble rock while it moves back to exposure after being buried by younger strata. The major boundaryconditions, the overall circulation pattern, and extrinsic factors and intrinsic mechanisms of karst development appear tochange considerably between the stages, resulting in characteristic styles of cave development and surface karst morphology,particularly distinct in case of gypsum karst.As gypsum is much more soluble than carbonates, it does not survive long in outcrops beyond arid areas. Wheregypsum is exposed to the surface with no substantial karstification formed during various stages of reburial, the developmentof epigene solution porosity in this rock is hindered due to the fast dissolution, being limited to flow paths in whichthe breakthrough conditions can be attained quickly. However, karst processes in gypsum develop extensively in intrastratalkarst settings, with inheritance from the deep-seated stage through the denuded one. Karstification may commence in anystage of intrastratal development, and during the next successive stage, the process, although in changed conditions, will beaffected significantly by the preformed solution porosity. Speleogenesis in deep-seated gypsum karst is exclusively hypogene.In subjacent karst, both hypogene and epigene speleogenesis may operate depending on the locally prevailing flowregime, but hypogene speleogenesis still dominates. In entrenched and denuded karst types, speleogenesis is overwhelminglyepigenic, but it is greatly facilitated by the presence of solution porosity inherited from the previous stages.Diverse and expressive karst landforms related to subsurface conduits evolve through different stages of the intrastratal karstdevelopment.The subsidence hazard in regions underlain by gypsum differs substantially between the karst types, so that one canobtain a kind of integrated general hazard assessment by classifying a given individual karst according to its evolution state.In general, various types of intrastratal karst, subjacent karst in particular, are the most potent in generating subsidence problems, whereas exposed karst types, particularly open karst, are the least prone to subsidence


Comment on Sandstone caves on Venezuelan tepuis: Return to pseudokarst? by R. Aubrecht, T. Lnczos, M. Gregor, J. Schlgl, B. Smda, P. Lisck, Ch. Brewer-Caras, L. Vlcek, Geomorphology 132 (2011), 351365, 2013, Sauro F. , Piccini L. , Mecchia M. , De Waele J.

In the recent work of Aubrecht et al. (2011) the presence of “unlithified or poorly-lithified beds” of sands in the quartz-sandstone stratigraphic succession is proposed as a key factor for speleogenesis in the Venezuelan tepuis.In this comment we observe that in the cited work the geologic history of the region, in terms of sedimentation environment, diagenesis and low grade burial metamorphism, has not been considered. Furthermore, the peculiar “pillar flow” columns that Aubrecht et al. describe as a proof of the unlithification are lacking in many other different cave systems in the same area.

Four critical points are discussed: the burial metamorphism of the Mataui Formation, the significance of the Schmidt Hammer measurements, the cave morphologies and the role of SiO2 dissolution. Finally we suggest that weathering, in its wider significance, is probably the triggering process in speleogenesis, and there is no need to invoke a differential diagenesis of the sandstone beds. ©


Geochemistry and isotope geochemistry of the Monfalcone thermal waters (northern Italy): inference on the deep geothermal reservoir, 2013, Petrini R. , Italiano F. , Ponton M. , Slejko F. F. , Aviani U. , Zini L.

Geochemical investigations were carried out to define the origin of the low- to moderate-temperature thermal waters feeding the Monfalcone springs in northern Italy. Chemical data indicate that waters approach the composition of seawater. Mixing processes with cold low-salinity waters are highlighted. The δ18O and δD values are in the range −5.0 to −6.4 ‰, and −33 to −40 ‰, respectively, suggesting the dilution of the saline reservoir by karst-type freshwaters. A surplus of Ca2+ and Sr2+ ions with respect to a conservative mixing is ascribed to diagenetic reactions of the thermal waters with Cretaceous carbonates at depth. The measured Sr isotopic composition (87Sr/86Sr ratio) ranges between 0.70803 and 0.70814; after correction for the surplus Sr, a 87Sr/86Sr ratio indicating Miocene paleo-seawater is obtained. The dissolved gases indicate long-lasting gas–water interactions with a deep-originated gas phase of crustal origin, dominated by CO2 and marked by a water TDIC isotopic composition in the range −5.9 to−8.8 and helium signature with 0.08 < R/Ra < 0.27, which is a typical range for the crust. A possible scenario for the Monfalcone thermal reservoir consists of Miocene marine paleowaters which infiltrated through the karstic voids formed within the prevalently Cretaceous carbonates during the upper Eocene emersion of the platform, and which were entrapped by the progressive burial by terrigenous sediments.


Comment on Sandstone caves on Venezuelan tepuis: Return to pseudokarst? by R. Aubrecht, T. Lnczos, M. Gregor, J. Schlgl, B. Smda, P. Lisck, Ch. Brewer-Caras, L. Vlcek, Geomorphology 132 (2011), 351365, 2013, Sauro Francesco, Piccini Leonardo, Mecchia Marco, De Waele Jo

In the recent work of Aubrecht et al. (2011) the presence of “unlithified or poorly-lithified beds” of sands in the   quartz-sandstone stratigraphic succession is proposed as a key factor for speleogenesis in the Venezuelan tepuis.   In this comment we observe that in the cited work the geologic history of the region, in terms of sedimentation   environment, diagenesis and low grade burial metamorphism, has not been considered. Furthermore, the   peculiar “pillar flow” columns that Aubrecht et al. describe as a proof of the unlithification are lacking in   many other different cave systems in the same area.   Four critical points are discussed: the burial metamorphism of the Mataui Formation, the significance of the   Schmidt Hammer measurements, the cave morphologies and the role of SiO2 dissolution. Finally we suggest   that weathering, in its wider significance, is probably the triggering process in speleogenesis, and there is no   need to invoke a differential diagenesis of the sandstone beds


Analysis of "standard" (Lipica) lemestone tablets and their weathering by carbonate staining and SEM imaging, a case study on the Vis island, Croatia, 2013, Krklec Kristina, Marjanac Tihomir, Perica Dražen

This paper focuses on the evolution and patterns of microscale weathering forms and dissolution rates of “standard” (Lipica) limestone tablets. Analysis of carbonate weathering using combination of methods (quantitative analysis by the weight loss of "standard" tablets, and qualitative analysis of the weathered surfaces by stained acetate peels and SEM imaging) showed that dissolution takes place not only at the surface of limestone tablets, but also along voids and cavities in limestone tablets which makes total weathering surface larger than the area of the tablet surface. Dissolution is more pronounced on the micritic calcite surfaces (due to different dissolution kinetics of carbonate minerals), resulting in lowering of the surface (calcite matrix) which causes gradual unburial and removal of authigenic dolomite grains.


The view of Maya cave ritual from the Overlook Rockshelter, Caves Branch River Valley, Central Belize, 2013, Wrobel G. D. , Shelton R. , Morton S. , Lynch J. , Andres C.

Archaeological investigations of the Overlook Rockshelter in the Caves Branch River Valley of central Belize offer a unique view of ancient Maya cave ritual through the complete recovery and analysis of all artifacts within the site’s two small activity areas. In general, the assemblage contains many of the same types of objects documented from other nearby caves and rockshelters. However, the nearly 1700 ceramics sherds showed almost no refits, demonstrating that sherds were deposited at the site individually, rather than as complete vessels. The human bone assemblage represents three or four individuals, with the majority of the bones comprising a single individual, and all of these were deposited as incomplete secondary interments. Analogies for this depositional behavior based on archaeological and ethnographic studies suggest that this rockshelter may represent a waypoint within a ritual circuit composed of multiple locations over which fragments of complete items such as ceramic vessels and secondary burials were spread.  

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EVOLVING INTERPRETATIONS OF HYPOGENE SPELEOGENESIS IN THE BLACK HILLS, SOUTH DAKOTA, 2014, Palmer A. N. , Palmer M. V.

The origin of caves in the Black Hills has long been debated. Their history is long and complex, involving early diagenesis, meteoric karst (now paleokarst), deep burial, tectonic uplift, and, finally, enlargement of previous voids to the caves of today. The final stage is usually the only one recognized and is the topic of this paper. Genetic hypotheses include artesian flow, rising flow (preferably thermal), diffuse infiltration, and mixing of various water sources. The last process best fits the regional setting and water chemistry.  


Karstification of Dolomitic Hills at south of Coimbra (western-central Portugal) - Depositional facies and stratigraphic controls of the (palaeo)karst affecting the Coimbra Group (Lower Jurassic), 2014, Dimuccio, Luca Antonio

An evolutionary model is proposed to explain the spatio-temporal distribution of karstification affecting the Lower Jurassic shallow-marine carbonate succession (Coimbra Group) of the Lusitanian Basin, cropping out in the Coimbra-Penela region (western-central Portugal), in a specific morphostructural setting (Dolomitic Hills). Indeed, in the Coimbra Group, despite the local lateral and vertical distributions of dolomitic character and the presence of few thick sandy-argillaceous/shale and marly interbeds, some (meso)karstification was identified, including several microkarstification features. All types of karst forms are commonly filled by autochthonous and/or allochthonous post-Jurassic siliciclastics, implying a palaeokarstic nature.

The main aim of this work is to infer the interplay between depositional facies, diagenesis, syn- and postdepositional discontinuities and the spatio-temporal distribution of palaeokarst. Here, the palaeokarst concept is not limited to the definition of a landform and/or possibly to an associated deposit (both resulting from one or more processes/mechanisms), but is considered as part of the local and regional geological record.

Detailed field information from 21 stratigraphic sections (among several dozens of other observations) and from structural-geology and geomorphological surveys, was mapped and recorded on graphic logs showing the lithological succession, including sedimentological, palaeontological and structural data. Facies determination was based on field observations of textures and sedimentary structures and laboratory petrographic analysis of thin-sections. The karst and palaeokarst forms (both superficial and underground) were classified and judged on the basis of present-day geographic location, morphology, associated discontinuities, stratigraphic position and degree of burial by post-Jurassic siliciclastics that allowed to distinguish a exposed karst (denuded or completely exhumed) than a palaeokarst (covered or partially buried).

A formal lithostratigrafic framework was proposed for the local ca. 110-m-thick combined successions of Coimbra Group, ranging in age from the early Sinemurian to the early Pliensbachian and recorded in two distinct subunits: the Coimbra formation, essentially dolomitic; and the overlying S. Miguel formation, essentially dolomitic-limestone and marly-limestone.

The 15 identified facies were subsequently grouped into 4 genetically related facies associations indicative of sedimentation within supra/intertidal, shallow partially restricted subtidal-lagoonal, shoal and more open-marine (sub)environments - in the context of depositional systems of a tidal flat and a very shallow, inner part of a low-gradient, carbonate ramp. In some cases, thick bedded breccia bodies (tempestites/sismites) are associated to synsedimentary deformation structures (slumps, sliding to the W to NW), showing the important activity of N–S and NNE–SSW faults, during the Sinemurian. All these deposits are arranged into metre-scale, mostly shallowing-upward cycles, in some cases truncated by subaerial exposure events. However, no evidence of mature pedogenetic alteration, or the development of distinct soil horizons, was observed. These facts reflect very short-term subaerial exposure intervals (intermittent/ephemeral), in a semiarid palaeoclimatic setting but with an increase in the humidity conditions during the eogenetic stage of the Coimbra Group, which may have promoted the development of micropalaeokarstic dissolution (eogenetic karst).

Two types of dolomitization are recognized: one (a) syndepositional (or early diagenetic), massive-stratiform, of “penesaline type”, possibly resulting from refluxing brines (shallow-subtidal), with a primary dolomite related to the evaporation of seawater, under semiarid conditions (supra/intertidal) and the concurrent action of microbial activity; another (b) later, localized, common during diagenesis (sometimes with dedolomitization), particularly where fluids followed discontinuities such as joints, faults, bedding planes and, in some cases, pre-existing palaeokarstic features.

The very specific stratigraphic position of the (palaeo)karst features is understood as a consequence of high facies/microfacies heterogeneities and contrasts in porosity (both depositional and its early diagenetic modifications), providing efficient hydraulic circulation through the development of meso- and macropermeability contributed by syn- and postdepositional discontinuities such as bedding planes, joints and faults. These hydraulic connections significantly influenced and controlled the earliest karst-forming processes (inception), as well as the degree of subsequent karstification during the mesogenetic/telogenetic stages of the Coimbra Group. Multiple and complex karstification (polyphase and polygenic) were recognized, including 8 main phases, to local scale, integrated in 4 periods, to regional scale: Jurassic, Lower Cretaceous, pre-Pliocene and Pliocene-Quaternary. Each phase of karstification comprise a specific type of (palaeo)karst (eogenetic, subjacent, denuded, mantled-buried and exhumed).

Finally, geological, geomorphological and hydrogeological characteristics allowed to describe the local aquifer. The elaborated map of intrinsic vulnerability shows a karst/fissured and partially buried aquifer (palaeokarst) with high to very high susceptibility to the contamination.


The fate of CO2 derived from thermochemical sulfate reduction (TSR) and effect of TSR on carbonate porosity and permeability, Sichuan Basin, China, 2015, Hao Fang, Zhang Xuefeng, Wang Cunwu, Li Pingping, Guo Tonglou, Zou Huayao, Zhu Yangming, Liu Jianzhang, Cai Zhongxian

This article discusses the role ofmethane in thermochemical sulfate reduction (TSR), the fate of TSR-derived CO2 and the effect of TSR on reservoir porosity and permeability, and the causes of the anomalously high porosity and permeability in the Lower Triassic soured carbonate gas reservoirs in the northeast Sichuan Basin, southwest China. The Lower Triassic carbonate reservoirs were buried to a depth of about 7000 m and experienced maximum temperatures up to 220 °C before having been uplifted to the present-day depths of 4800 to 5500 m, but they still possess porosities up to 28.9% and permeabilities up to 3360 md. The present-day dry gas reservoirs evolved from a paleo-oil accumulation and experienced varying degrees of TSR alteration as evidenced from the abundant sulfur-rich solid bitumens and varying H2S and CO2 concentrations. TSR occurred mainly within the oil and condensate/wet gas windows, with liquid hydrocarbons and wet hydrocarbon gases acting as the dominant reducing agents responsible for sulfate reduction, sulfur-rich solid bitumen and H2S generation, and calcite precipitation. Methane-dominated TSR was a rather late event and had played a less significant role in altering the reservoirs. Intensive H2S and CO2 generation during TSR resulted in calcite cementation rather than carbonate dissolution, which implies that the amount of water generated during TSR was volumetrically insignificant. 13C-depleted CO2 derived from hydrocarbon oxidation preferentially reacted with Ca2+ to form isotopically light calcite cements, and the remaining CO2 re-equilibrated with the 13C-enriched water–rock systems with its δ13C rapidly approaching the values for the host rocks, which accounted for the observed heavy and relatively constant CO2 δ13C values. The carbonate reservoirs suffered from differential porosity loss by TSR-involved solid bitumen generation and TSR-induced calcite and pyrite precipitation. Intensive TSR significantly reduced the porosity and permeability of the intervals expected to have relatively high sulfate contents (the evaporative-platform dolostones and the platform-margin shoal dolostones immediately underlying the evaporative facies). Early oil charge and limited intensity of TSR alteration, together with very low phyllosilicate content and early dolomitization, accounted for the preservation of anomalously high porosities in the reservoirs above the paleo-oil/water contact. A closed system seems to have played a special role in preserving the high porosity in the gas zone reservoirs below the paleo-oil/water contact. The closed system, which is unfavorable for deep burial carbonate dissolution and secondary porosity generation, was favorable for the preservation of early-formed porosity in deeply buried carbonates. Especially sucrosic and vuggy dolostones have a high potential to preserve such porosity.


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