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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 neuromast is one of the individual sense organs that make up the lateral line systems of fishes and amphibians [23]. see also cupula.?

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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 aging (Keyword) returned 89 results for the whole karstbase:
Showing 1 to 15 of 89
The `human revolution' in lowland tropical Southeast Asia: the antiquity and behavior of anatomically modern humans at Niah Cave (Sarawak, Borneo), , Barker G, Barton H, Bird M, Daly P, Datan I, Dykes A, Farr L, Gilbertson D, Harrisson B, Hunt C,
Recent research in Europe, Africa, and Southeast Asia suggests that we can no longer assume a direct and exclusive link between anatomically modern humans and behavioral modernity (the `human revolution'), and assume that the presence of either one implies the presence of the other: discussions of the emergence of cultural complexity have to proceed with greater scrutiny of the evidence on a site-by-site basis to establish secure associations between the archaeology present there and the hominins who created it. This paper presents one such case study: Niah Cave in Sarawak on the island of Borneo, famous for the discovery in 1958 in the West Mouth of the Great Cave of a modern human skull, the `Deep Skull,' controversially associated with radiocarbon dates of ca. 40,000 years before the present. A new chronostratigraphy has been developed through a re-investigation of the lithostratigraphy left by the earlier excavations, AMS-dating using three different comparative pre-treatments including ABOX of charcoal, and U-series using the Diffusion-Absorption model applied to fragments of bones from the Deep Skull itself. Stratigraphic reasons for earlier uncertainties about the antiquity of the skull are examined, and it is shown not to be an `intrusive' artifact. It was probably excavated from fluvial-pond-desiccation deposits that accumulated episodically in a shallow basin immediately behind the cave entrance lip, in a climate that ranged from times of comparative aridity with complete desiccation, to episodes of greater surface wetness, changes attributed to regional climatic fluctuations. Vegetation outside the cave varied significantly over time, including wet lowland forest, montane forest, savannah, and grassland. The new dates and the lithostratigraphy relate the Deep Skull to evidence of episodes of human activity that range in date from ca. 46,000 to ca. 34,000 years ago. Initial investigations of sediment scorching, pollen, palynomorphs, phytoliths, plant macrofossils, and starch grains recovered from existing exposures, and of vertebrates from the current and the earlier excavations, suggest that human foraging during these times was marked by habitat-tailored hunting technologies, the collection and processing of toxic plants for consumption, and, perhaps, the use of fire at some forest-edges. The Niah evidence demonstrates the sophisticated nature of the subsistence behavior developed by modern humans to exploit the tropical environments that they encountered in Southeast Asia, including rainforest

Abstract: Darwin and Diprotodon: The Wellington Cave Fossils and the Law of Succession IN: Proceedings of the Linnean Society of New South Wales 104, 1980 for 1979:265-272, 1981, Dugan, Kathleen G.

The fossils from Wellington Caves, some of them 'giant', are well known to Australian speleologists, finds of importance for the study of Australian fauna from early discovered caves. What I think we did not appreciate was that the Wellington 'bones' have a place in the world history of science of significance also, the theme of this paper. Many of you will have watched the BBC-TV series on 'The Voyage of the Beagle'; much was made of the importance to Darwin in developing his theory of evolution of the fossils he found in southern South America. There fossils of giant relatives of sloths, llamas and armadillos helped to make clear to him the notion of the geological succession of life, a basic part of his theory along with the idea of natural selection to which the finches and the tortoises of the Galapagos Islands proved crucial. However it seems that Darwin was previously aware of the similar significance of the Wellington Caves bones for the law of succession from Charles Lyell's Principles of Geology which quotes William Clift's identifications of dasyures, wombats and kangaroos amongst them. The fact that these recently extinct animals were closely related to the distinctive modern marsupial fauna of Australia counted much against earlier conceptions such as Cuvier's catastrophic theory or Buckland's ideas of successive divine creations within a short time span. Watchers of the TV series will remember the devious role played by the palaeontologist, Sir Richard Owen, in organising public opposition to Darwin at the famous Oxford meeting of the British Association for the Advancement of Science. This article relates the series of rearguard actions of Owen to maintain that there was a fossil elephant component in the ancient Australian fauna, damaging to Darwinism. But the growing evidence from Australia, not all of it from caves, of course, finally extinguished this red herring, started by that doctrinaire N.S.W. colonial, the Reverend John Dunmore Lang.


Further Studies at the Blue Waterholes, Cooleman Plain, N.S.W., 1969-77, Part I, Climate and Hydrology, 1983, Jennings, J. N.

Previous study of the temporal and spatial distribution of limestone solution at Cooleman Plain rested on monthly discharges and water analyses of the Blue Waterholes over 4 years. For this study automatic recording of discharge (8 years), rainfall (8 years), evaporation (7 years) and temperature (4 years) was attended by variable success in the face of interference, rigorous climate and inaccessibility. The most important aspect of the climatic data was the support obtained for the earlier assumption of similar water balances in the forested igneous frame and the grassland limestone plain. Runoff was again shown to be highly variable from year to year and to have an oceanic pluvial regime, with a summer-autumn minimum owing much to evapo-transpiration. The flow duration curve from daily discharges puts this karst amongst those where neither extremely high nor low flows are important. The stream routing pattern offsets the effect of 71% of the catchment being on non-karst rocks, damping flood events. An inflection of 700 l/s in a flow duration plot based on discharge class means is interpreted as the threshold at which surface flow down North Branch reaches the Blue Waterholes. Storages calculated from a generalised recession hydrograph parallel Mendip data where baseflow (fissure) storage provides most of the storage and quickflow (vadose) storage only a secondary part. Water-filled conduit storage (the phreas) could not be determined but is considered small. The baseflow storage seems large, suggesting that it can develop independently of caves in some measure. A quickflow ratio for floods derived by Gunn's modification of the Hewlett and Hibbert separation line method appears relatively low for a mainly non-karst catchment and is again attributed to the routing pattern. For analysis of variation of the solute load over time, estimates of daily discharge during gaps in the record where made for the author by Dr. A.J. Jakeman and Mr. M.A. Greenaway (see Appendix). A small number of discharge measures of two contrasted allogenic catchments of the igneous frame shows a unit area yield close to that for the whole catchment. Together with the guaging of most of the allogenic inputs, this supports the idea that the water yield is much the same from the forested ranges and the grassland plain. This is important for the estimation of limestone removal rates.


Quelques aspects du karst en Chine, 1985, Tricart, J.
Some characteristic features of karst in China Karst terrain is widespread in China: some 2,000,000km2, corresponding to 20-25% of the whole surface of the country. It occurs at very different altitudes and under quite different climates, from the region of Zhoukoudian, where has been found the skull of the Pekin Man, to the Tibet Plateau, where there is presently permafrost conditions, and up to southern tropical moist China, near Canton and Guilin. Recent chinese investigations have proved that most karst features are old. In Southern China a tropical karst (tower-karst or "mogotes" karst) is associated with lacustrine deposits containing the well-known Hipparion Fauna, of Miocene age. Its predates the intensive uplift of the Himalaya and of the Tibet, which has begun during the Pliocene and has continued during all the Pleistocene. The same fossils have been found in this tropical karst in present permafrost areas, above 5,000m. In the region of Guilin (Guangxi Province), this tropical karst has been described. There is evidence for the former existence of a covered karst, where limestones and dolomitic limestones were covered by a thick layer of reddish residual clays, with limonite. This mantle has been stripped during different periods of drier and probably cooler climate, has suggested by pollen spectra. In some places, these residual products have been trapped into pits, cracks, and caves. We have observed a small quantity of red clay painting limestone stalactites and sinters (Chuanshan and Leng Yin Yen Caves, in the surroundings of Guilin). They present sometimes a mining interest and some extractive industries are presently active (limonite, cassierite, etc.). Many caves have been surveyed by the Institute of Karst geology, in Guilin. Some have been equiped for tourism, around Guilin. All these caves are old. Some radiocarbon dating of speleothems yield ages of 33,000 year BP. The famous carving of the Leng Yen Cave have not been affected by calcite deposition from dripping since at least 500 years. The large caves that have been surveyed should correspond to a long evolution span. Along the Lijiang River, at least two terraces can be observed. They are built with gravels and pebbles, covered with thinner sand and loam, suggesting climatic changes, also attested by the changes of fauna and vegetation. These past cooler periods are characterised by an opened vegetation, with the striping of the old weathering cover of the former tropical karst. These karst terrains have been investigated in China for management purposes. Groundwater oscillations have frequently resulted in land subsidences damaging buildings, and in dramatic collapses destroying fields, roads. Sometimes, underground collapse plugged caves and dammed underground rivers, resulting in floodings. The caves are frequently used as reservoirs for irrigation and power plants.

Sur l'existence de palo-crypto-karsts dans le bassin de l'Oubangui (Rpublique centrafricaine), 1988, Boulvert Y, Salomon J. N.
PALEO-CRYPTO-KARSTS IN THE UBANGUI BASIN (Centrafrican Republic) - The occurrence of many indications of carbonated bed formations had been reported by numerous naturalists, and more particularly the presence of a lot of closed basins, which look like dolines, spreaded out in superficial weathered formations. This permits to presume the existence of ancient crypto-karsts in the Ubangui basin. The show off by well drilling of the so-called Bakouma sequence, which is carbonated, at the end of the sixties, confirmed the existence of a very old paleokarst. Others could exist, especially where closed basins open out on the surface. The problem is to know which part is due to the karst withdrawing in the form elaboration. The authors suggest making researches into water analysis for the first results achieved on the Ubangi basin are encouraging. At last thanks the cross-checking of the numerous indications, a first cartography of the carbonated formations in the Centrafrican Republic is proposed.

Laboratory studies of predatory behaviour in two subspecies of the Carabid cave beetle: Neaphaenops tellkampfi., 1990, Griffith David M.
Comparative studies on the foraging behaviour of Neaphaenops tellkampfi tellkampfi and N. t. meridionalis demonstrated adaptation to different environments. The southern subspecies N. t. meridionalis, which is found in wet muddy caves where cave cricket eggs are unlikely prey, did not locate buried cricket eggs and dug fewer and less accurate holes in the lab than the nominate subspecies. N. t. tellkampfi, which reaches high densities in sandy deep cave environments where cricket eggs are the only viable prey, gained significantly greater weight than meridionalis when presented buried cricket eggs as prey. There was no difference with respect to weight change between the subspecies in the presence of Ptomaphagus larvae. N. t. meridionalis gained weight at a significantly greater rate than the nominate subspecies with enchytraeid worms as prey. Enchytraeid worms represent the natural prey most likely to be encountered by N. t. meridionalis. 25% of beetle holes were dug deep enough to potentially located buried cricket eggs. Since Hubbell and Nortons' morphological data on the relationship between cricket ovipositor length and beetle predation have some problems with sample sizes and minor assumptions I conclude that there are no unequivocal data that support the possibility of coevolution between Neaphaenops and Hadenoecus.

Atomic-scale imaging of calcite growth and dissolution in real time., 1992, Hillner P. E. , Gratz A. J. , Manne S. , Hansma P. K.

Reactivated interstratal karst--example from the Late Silurian rocks of western Lake Erie (U.S.A.), 1992, Carlson Eh,
Interstratal karst developed in the Late Silurian rocks of western Lake Erie that, after a long interruption, was exhumed and reactivated. The dissolution front of the G evaporite of the Salina Group receded in the downdip direction during these two well-documented periods of subaerial exposure. The karst features that developed in the overlying Bass Islands Dolomite (Pridolian) consist of a large tabular body of collapse breccia and a number of smaller features including breccia pipes, partially filled pipes, blister caves and collapse dolines.The tabular breccia body and the breccia pipes, which originated penecontemporaneously during post-Silurian and pre-Middle Devonian subaerial exposure, occur along the updip edge of the present outcrop belt of the dolostone. They are monolithologic, fragment-supported rubble breccias, with the pipes exhibiting a greater fragment displacement, rotation and rounding, and a smaller fragment size. The matrix sediment of the tabular body is a quartz sand, an equivalent of the basal sandstone that filtered down from the erosion surface. The presence in the matrix sediment of nodular celestite, a later replacement of evaporites that formed when the sediment was still soft, indicates that a sabkha environment existed at the time the breccia was infilled. The partially filled pipes, which form cylindrical caves that are lined with late diagenetic celestite, are believed to be cogenetic with the collapse breccias.The blister caves and dolines occur downdip from the breccias, postdating Pleistocene glaciation and predating isostatic rebound. These caves are isolated, crescent- or oval-shaped openings with domed roofs, averaging about 60 m in width and 4 m in height. The hydration and resulting expansion of lenticular bodies of anhydrite along the receding solution front of the G unit is believed to be the cause of doming. The numerous crescentic caves, originating from the dissolution of this gypsum and the subsequent collapse of the domed roofs, are expressed at the surface as shallow dolines

REACTIVATED INTERSTRIATAL KARST EXAMPLE FROM THE LATE SILURIAN ROCKS OF WESTERN LAKE ERIE (USA), 1992, Carlson Eh,
Interstratal karst developed in the Late Silurian rocks of western Lake Erie that, after a long interruption, was exhumed and reactivated. The dissolution front of the G evaporite of the Salina Group receded in the downdip direction during these two well-documented periods of subaerial exposure. The karst features that developed in the overlying Bass Islands Dolomite (Pridolian) consist of a large tabular body of collapse breccia and a number of smaller features including breccia pipes, partially filled pipes, blister caves and collapse dolines. The tabular breccia body and the breccia pipes, which originated penecontemporaneously during post-Silurian and pre-Middle Devonian subaerial exposure, occur along the updip edge of the present outcrop belt of the dolostone. They are monolithologic, fragment-supported rubble breccias, with the pipes exhibiting a greater fragment displacement, rotation and rounding, and a smaller fragment size. The matrix sediment of the tabular body is a quartz sand, an equivalent of the basal sandstone that filtered down from the erosion surface. The presence in the matrix sediment of nodular celestite, a later replacement of evaporites that formed when the sediment was still soft, indicates that a sabkha environment existed at the time the breccia was infilled. The partially filled pipes, which form cylindrical caves that are lined with late diagenetic celestite, are believed to be cogenetic with the collapse breccias. The blister caves and dolines occur downdip from the breccias, postdating Pleistocene glaciation and predating isostatic rebound. These caves are isolated, crescent- or oval-shaped openings with domed roofs, averaging about 60 m in width and 4 m in height. The hydration and resulting expansion of lenticular bodies of anhydrite along the receding solution front of the G unit is believed to be the cause of doming. The numerous crescentic caves, originating from the dissolution of this gypsum and the subsequent collapse of the domed roofs, are expressed at the surface as shallow dolines

The cricket fauna of Chiapanecan caves (Mexico): systematics, phylogeny and the evolution of troglobitic life (Orthoptera, Grylloidea, Phalangopsidae, Luzarinae), 1993, Desuttergrandcolas Laure
The present study deals with the cavernicolous Grylloidea of Chiapas. It details the composition of this fauna, which belongs exclusively to the Phalangopsid group Amphiacustae, and considers its troglobitic evolution in the methodological framework of Comparative Biology. This method consists in analysing the evolution of biological features in reference to phylogeny, using character state optimization. The material studied comes mostly from Italian biospeological expeditions, but also from the authors work in Mexico, from North American biospeological expeditions achieved in Central America and the West Indies, and from the collections of the Academy of Natural Sciences of Philadelphia, the Museum National d'Histoire naturelle de Paris and the University of Michigan Museum of Zoology. I first present a systematic and phylogenetic analysis of Amphiacustae. Six new genera are defined and the genus Amphiacusta Saussure, 1874 is clearly delimited; twenty-three of the twenty six species considered in the paper are new and described. A key for genera and species groups is given. Phylogenetic relationships among genera are established using cladistics (implicit enumeration of Hennig 86 program). The evolution of troglobitic Amphiacustae is then analyzed. Available data on the biology of Amphiacust genera are presented and compared with what is known on other Phalangopsidae. Three biological attributes are moreover defined (troglobitic versus non troglobitic; cavernicolous versus non cavernicolous; leaf litter foraging versus leaf litter not foraging). The mapping of the attributes upon our cladogram has shown that Amphiacustae evolved twice toward cave life and that their ancestral habitat could be characterized by cavernicolous habits and leaf litter foraging. The results are discussed in reference to theories on troglobitic taxa evolution, and to the exaptation concept of Gould & Vrba (1982). This leads to three main conclusions: 1/ Amphiacust adaptation to caves could be the result of a tentative to exploit karstic resources in Central America; 2/ An epigean dispersion by cave living species can be hypothesized; 3/ For Grylloidea, having cavernicolous habits at ground level appears to be exaptative to troglobitic life.

RELATIONSHIP BETWEEN FRACTURES AND KARSTIFICATION - THE OIL-BEARING PALEOKARST OF ROSPO MARE (ITALY), 1994, Soudet H. J. , Sorriaux P. , Rolando J. P. ,
The Rospo Mare oil field is located in the Adriatic Sea, 20 km off the Italian coast. The reservoir lies at a depth of 1300 m and consists of a paleokarst oi Oligocene to Miocene age which developed within Cretaceous limestones, now covered by 1200 m of Mio-Pliocene sequences. The oil column is about 140 m 8 high. The karstic nature of the reservoir was identified through vertical, cored drill holes which allowed us to analyse the various solution features and the sedimentary infilling (speleothems, terra rossa, marine clays), as well as their vertical distribution. Erosion morphology at the top of the karst is highly irregular, including in particular paleovalleys as well as many pit-shaped sink holes. Detailed geophysical knowledge of that morphology helped to optimize the development of the field through horizontal drilling. Observations concerning the upper part of the reservoir were compared to a palaeokarst of the same age, outcropping widely onshore, in quarries located nearby. The Rospo Mare paleokarst is an integral part of the ante Miocene paleokarst assemblages of the periphery of the Mediterranean which were formed in tropical conditions. Only the fractures enhanced by meteoric water during the formation of the karat are important for reservoir connectivity. During the formation of the karst there were several phases of dissolution and infilling which modified the geometry of the open fissures and only these fractures play an important role in the reservoir drainage. Vertically we can distinguish three very different zones from top to bottom: at the top the epikarst (0-35 m) in a zone of extension. All the fractures have been enlarged by dissolution but the amount of infilling by clay is substantial. The clays are derived either from alteration of the karat fabric or by deposition during the Miocene transgression; the percolation zone (15-45 m) is characterized by its network of large fractures vertically enlarged by dissolution which corresponds to the relict absorption zones in the paleokarst. These fractures, which usually have a pluridecametric spacing, connect the epi-karst with the former sub-horizontal river system. This zone has been intersected by the horizontal wells during the field development. In this zone there are local, horizontal barriers oi impermeable clay which can block vertical transmissibility. In these low permeability zones the vertical fractures have not been enlarged due to dissolution hence the horizontal barrier; the zone of underground rivers (35-70 m) is characterized by numerous horizontal galleries which housed the subterranean ground water circulation. When these fissures are plurimetric in extent this can lead to gallery collapse with the associated fill by rock fall breccia. This can partly block the river system but always leaves a higher zone of free circulation with high permeabilities of several hundreds of Darcys. These galleries form along the natural fracture system relative to the paleohydraulic gradient which in some cases has been preserved. The zone below permanent ground water level with no circulation of fluids is characterized by dissolution limited to non-connected vugs. Very locally these fissures can be enlarged by tectonic fractures which are non-connected and unimportant for reservoir drainage. Laterally, only the uppermost zone can be resolved by seismic imaging linked with horizontal well data (the wells are located at the top of the percolation zone). The Rospo Mare reservoir shows three distinct horizontal zones: a relict paleokarst plateau with a high index of open connected fractures, (area around the A and B platforms); a zone bordering the plateau (to the north-east of the plateau zone) very karstified but intensely infilled by cap rock shales (Miocene - Oligocene age); a zone of intensely disturbed and irregular karst paleotopography which has been totally infilled by shales. The performance of the production wells is dependent on their position with respect to the three zones noted above and their distance from local irregularities in the karst paleotopography (dolines, paleovalleys)

Geomagnetic palaeosecular variation recorded in North And Central American speleothems, PhD thesis, 1995, Lean, C. M. B.

The aim of this project was to collect samples of stalagmites from Northern and Central America in order to produce records of the palaeosecular variation of the earth's magnetic field. Two stalagmites were sampled from Western Canada and ten from Mexico and Guatemala which could be compared with contemporaneous stalagmite records from these areas (Latham, 1981; Latham et al, 1982; 1986; 1987; 1989).
The stalagmites were generally weakly magnetised but remanence directions were stable upon stepwise thermal and alternating-field demagnetisation. Consistency in directions recorded between central and corresponding lateral sub-samples within two stalagmites (MSC2 from Canada and CP1 from Guatemala) inferred that any depositional errors caused by surface effects were less than the measurement errors. Grain size analysis showed the presence of a fine-grained magnetic fraction (0.01 - 0.1?:m) sourced from the cave drip-waters (either by direct deposition or by chemical precipitation) and a coarser magnetic fraction (0.01 - >10?:m) sourced from the flood-borne detritus. The latter source was dominant in stalagmites which were regularly inundated with water. The type of magnetic mineral present was determined by the geology of the catchment area; magnetite dominated in the Vancouver Island stalagmites, titanomagnetite in the Mexican stalagmites and haematite in the Guatemalan stalagmite.
Uranium-series dating of samples was hindered by the young ages of many of the samples, by low uranium concentrations and by the presence of allogenic thorium. If significant amounts of allogenic thorium were present, a sample age could be calculated based on an estimate of the initial thorium ratio ([230Th/232Th]0). Analysis of samples from Sumidero Recuerdo in Mexico, however, suggested that this ratio is not constant with time and may vary by a factor of two over approximately 1700 years. Due to these imprecisions many dates were out of stratigraphic sequence and age estimates were made assuming constant growth rates, except where growth had ceased for a finite length of time.
Records of sequential change of palaeomagnetic direction were obtained from the Mexican stalagmite SSJ3 and the Canadian stalagmite MSC2. The reliability of the latter record was confirmed by comparison with another Canadian stalagmite record (Latham et al, 1987) and contemporaneous lacustrine records. Other records were disappointing due to poor temporal resolution; each sub-sample represented a period of approximately 1000 years in Mexican stalagmites SSJ2 and SSJ4. Such slow growth rates are insufficient for the resolution of secular variation features with periods of less than 2000 years and are only suitable to gain information about the nature of long-term secular variations, for example the far-sided virtual geomagnetic poles and low inclinations predominant throughout the Holocene in Southern Mexico.
The existence of matching contemporaneous stalagmite records of secular variation together with the demonstrated lack of depositional inclination errors is encouraging, despite the sometimes "hit or miss" aspects of sample selection. Nevertheless it has been proved that speleothem records have the potential to complement the existing archaeomagnetic, lava and lacustrine data.


3-D seismic evidence of the effects of carbonate karst collapse on overlying clastic stratigraphy and reservoir compartmentalization, 1996, Hardage B. A. , Carr D. L. , Lancaster D. E. , Simmons J. L. , Elphick R. Y. , Pendleton V. M. , Johns R. A. ,
A multidisciplinary team, composed of stratigraphers, petrophysicists, reservoir engineers, and geophysicists, studied a portion of Boonsville gas field in the Fort Worth Basin of north-central Texas to determine how modern geophysical, geological, and engineering techniques can be combined to understand the mechanisms by which fluvio-deltaic depositional processes create reservoir compartmentalization in a low- to moderate-accommodation basin. An extensive database involving well logs: cores, production, and pressure data from more than 200 wells, 26 mi(2) (67 km(2)) of 3-D seismic data, vertical seismic profiles (VSPs), and checkshots was assembled to support this investigation. We found the mast Important geologic influence on stratigraphy and reservoir compartmentalization in this basin to be the existence of numerous karst collapse chimneys over the 26-mi(2) (67 km(2)) area covered by the 3-D seismic grid, These near-vertical karst collapses originated in, or near, the deep Ordovician-age Ellenburger carbonate section and created vertical chimneys extending as high as 2500 fl (610 m) above their point of origin causing significant disruptions in the overlying elastic strata. These karst disruptions lend to be circular in map view, having diameters ranging from approximately 500 ft (150 m) to as much as 3000 ft (915 m) in some cases. Within our study area, these karat features were spaced 2000 ft (610 m) to 6000 ft (1830 m) apart, on average. The tallest karst collapse zones reached into the Middle Pennsylvanian Strawn section, which is some 2500 ft (760 m) above the Ellenburger carbonate where the karst generation began. We used 3-D seismic imaging to show how these karst features affected the strata above the Ellenburger and how they have created a well-documented reservoir compartment in the Upper Caddo, an upper Atoka valley-fill sandstone that typically occurs 2000 ft (610 m) above the Ellenburger. By correlating these 3-D seismic images with outcrops of Ellenburger karat collapses, we document that the physical dimensions (height, diameter, cross-sectional area) of the seismic disruptions observed in the 3-D data equate to the karst dimensions seen in outcrops. We also document that this Ellenburger carbonate dissolution phenomenon extends over at least 500 mi (800 km), and by inference we suggest karst models like we describe here may occur in any basin that has a deep, relatively thick section of Paleozoic carbonates that underlie major unconformities

The Chalk as a karstified aquifer: closed circuit television images of macrobiota, 1997, Waters A. , Banks D. ,
The use of closed circuit television (CCTV) imaging in the Chalk aquifer of the Thames catchment of southern England, has shed much light on the aquifer's flow mechanisms. CCTV images indicate that flow to a Chalk abstraction borehole is typically via a limited number of highly transmissive solutionenhanced fracture features. These bear some similarities to conduits found in true karstic aquifer systems, and have implications for the modelling of mass transport in the Chalk aquifer. Another feature, typical of karst aquifers, noted during CCTV surveys is the occasional presence of macroscopic biota, arthropods and annelids, apparently inhabiting the Chalk aquifer system

Thalweg variability at bridges along a large karst river: the Suwannee River, Florida, 1998, Mossa J. , Konwinski J. ,
Geomorphologists and engineers have different perspectives and approaches for examining river channels and the changes that occur during floods. The field-oriented approach typically adopted by geomorphologists has little predictive ability and design usefulness. In contrast, the empirical approach adopted by engineers is based on predictive equations or models that often differ greatly from reality. Such equations are not based on comprehensive field data and often fail to consider a number of site conditions, especially geology and geomorphology. Yet, in order for geomorphic techniques to be useful to the design and planning of engineering structures such as bridges, it is important that sufficient observations exist in order to characterize long-term and short-term changes in bottom topography and scour potential. Six gaging stations on the Suwannee River, a large river draining karst terrain in the southeastern US, were used to examine the temporal variability in thalweg elevation, the deepest point in a given cross-section. The cross-sections have maximum thalweg variability of just a few meters, despite the occurrence of several large floods. suggesting that the bottoms are fairly stable. Historical approaches can be applied to design the length and depth placement of pilings by providing information on site conditions not considered in engineering equations, such as response of bottom materials to various flow conditions, and thus have potential benefits to public safety and cost effectiveness. (C) 1998 Elsevier Science B.V

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