Karst and Cave RSS news feed Like us on Facebook! follow us on Twitter!
Community news

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 capillary water is 1. water held in the soil above the phreatic surface by capillary forces [22]. 2. soil water above hydroscopic moisture and below the field capacity [22].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
See all featured articles
Featured articles from other Geoscience Journals
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
See all featured articles from other geoscience journals

Search in KarstBase

Your search for exposure (Keyword) returned 139 results for the whole karstbase:
Showing 1 to 15 of 139
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

Physical and Physiological Factors in Fatal Exposures to Cold, 1967, Kreider Marlin B.

Studies on the response of healthy English Speleologists to exposure to Histoplasmosis Infection, 1974, Frankland J. C.

The New Guinea Expedition, 1975 - Notes on Histoplasmosis Exposure, 1976, Frankland J. C.

Hydrological and chemical investigations of running waters of the Schlitzerland (Western Germany). A. Springs, I. Survey., 1976, Brehm Jorg
In a Triassic sandstone woodland (Schlitzerland in Hesse, Western Germany) 17 springs were hydrologically and hydrochemically investigated throughout one year (April 1973; April 1974). Measurements were carried out on water volume, temperature, electrolytical conductivity, pH, aikalinity, chlorinity, dissolved molecular oxygen, dissolved organic material (COD), ammonia, nitrite, nitrate, and free phosphate. Among the hydrochemical factors investigated the pH-value was closely related especially to the micro-climate in the spring drainage area. In particular the pH rose both with increasing length of the drainage area and within the same spring with decreasing water supply. On the other hand the pH-value diminished with increasing altitude of the drainage area. Simultaneously the highest values were found on SW-slopes and the lowest ones in NE-exposures.

The karst of Transvaal (South Africa)., 1976, Kavalieris I. , Martini Jacques E. J.
The Transvaal Karst is a world important example of a Karst developed on a very old dolomite. Its unique character is due to the composition of the rock and history of development. The dissolution of the dolomite is interesting and has an important effect on the character of the caves developed. The caves preserved in this area include the longest known in South Africa and are perhaps among the largest dolomite systems known in the world. They are very old and in some cases contain important palaeontological deposits (Australopithecine fauna). The caves to various degrees are in a state of de-generation, having been exposed for a very long period above the water-table. For the greater part of the Karst area, aggressive vadose waters, and long exposure has resulted in the accumulation of a thick covering of residual material. The plateau-like geomorphology and low rainfalls has prevented physical erosion and significant removal of this debris from the land surface. The caves themselves are often characterized by collapse and in general lack of formations. Massive calcite formation in the caves is usually partly or nearly completely redissolved and are relics of past colder climatic periods with winter rains. Formations active now are small, usually delicate and often due directly to evaporation. The heavy mantle of residual debris preserved under some of the more ancient of South African landsurface relics (the African Surface) poses a serious economic problem of stability, with mans' utilization of the environment. A greater understanding of the Karst, its evolution and properties is thus of considerable practical importance.

The Age of Exposure of Limestone Pavements - A Pilot Lichenometric Study in Co. Clare, Eire, 1979, Trudgill S. T. , Crabtree R. W. , Walker P. J. C.

Carbonate rocks in the Black Sea basin: indicators for shallow water and subaerial exposure during Miocene--Pliocene time, 1979, Stoffers P. , Muller G. ,
Drilling in the Black Sea in general revealed three types of sediments: terrigenous, chemical, and biogenic. Terrigenous muds predominate in the Pleistocene whereas chemical sediments are abundant in the lower Pleistocene--Pliocene to Late Miocene sedimentary section. Biogenic constituents play a minor role only. The chemical sediments include calcite (lake chalk), Mg-calcite, aragonite, siderite and dolomite. Among these, the dolomites of Pliocene to Late Miocene age are most interesting. They were encountered in the two drill sites close to the Bosporus drilled in 2115 to 1750 m water depth, respectively. The dolomites show a great variety of criteria (e.g. intraclasts, algae mats, crusts, pellets, oolites), indicating a shallow water environment with occasional subaerial exposure and supratidal evaporitic conditions. The formation of these shallow water carbonates in the Black Sea is supposed to correlate with the Messinian salinity crisis in the Mediterranean

Variation of Hardness in Cave Drips at Two Tasmanian Sites, 1981, Goede, Albert

Thirteen consecutive monthly samples were collected from two drip sites at each of two Tasmanian caves: Little Trimmer at Mole Creek and Frankcombe Cave in the Florentine Valley. At one of the two drip sites in Little Trimmer a positive relationship was found between the logarithm of precipitation and the total hardness without any detectable lag effect. No such relationship was detected at the other drip site despite its close proximity. At both drip sites the hardness values fail to show a seasonal pattern and are clearly unrelated to surface temperature variations. In strong contrast both drip sites in Frankcombe Cave showed significant seasonal variation and close positive correlation with mean monthly temperature with lag times of one and two months respectively. At one of the two drip sites the influence of monthly precipitation on variations in drip hardness could also be detected. The strong temperature dependence of cave drip hardness values at these sites may well be due to soil exposure to direct insolation following recent clearfelling and burning of vegetation in the area.


Barbuda--an emerging reef and lagoon complex on the edge of the Lesser Antilles island are, 1985, Brasier M, Donahue J,
The Pliocene to Holocene limestones of Barbuda have formed on a wide, shallow, outlying bank of the Lesser Antilles island arc, some 50 km east of the older axis of the Limestone Caribbees and 100 km east of the newer axis of the active Volcanic Caribbees. Contrasts with neighbouring islands of similar size include the lack of exposed igneous basement or mid-Tertiary sediments, the dominance of younger flat-lying carbonates, and the greater frequency of earthquake shocks. The history of emergence of the island has been studied through aerial reconnaissance, mapping, logging, hand coring, facies and microfacies analysis. These show a pattern of progressively falling high sea level stands (from more than 50 m down to the present level) on which are superimposed at least three major phases of subaerial exposure, when sea levels were close to, or below, their present level. This sequence can be summarized as follows: 1, bank edge facies (early Pliocene Highlands Formation) deposited at not more than c. 50-100 m above the present sea level; 2, emergence with moderate upwarping in the north, associated with the Bat Hole subaerial phase forming widespread karst; 3, older Pleistocene transgression with fringing reefs and protected bays formed at l0 to l5 m high sea level stands (Beazer Formation); 4, Marl Pits subaerial phase with widespread karst and soil formation; 5, late Pleistocene transgression up to m high stand with fringing and barrier reefs, protected backreefs and bays (Codrington Formation Phase I); 6, gradual regression resulting in emergence of reefs, enclosure of lagoons, and progradation of beach ridges at heights falling from c. 5 m to below present sea level (Codrington Phase II); 7, Castle Bay subaerial phase produced karst, caliche and coastal dunes that built eastwards to below present sea level; and 8, Holocene transgression producing the present mosaic, with reefs, lagoons and prograding beach ridge complexes, with the present sea level reached before c. 4085 years BP. The evidence suggests that slight uplift took place in the north of the island after early Pliocene times. Subsequent shoreline fluctuations are consistent with glacio-eustatic changes in sea level, indicating that the island has not experienced significant uplift during the Quaternary

Wheres the Histo? Histoplasma in Chillagoe Caves area, North Queensland, Australia., 1988, Carol, Eileen M.

Ideal climatic and ecological conditions in many caves in the Chillagoe area suggest the existence of Histoplasma capsulatum. A study in progress proposes to identify those caves that may be reservoirs for the organism, thus presenting a potential health risk for cave visitors. Soil samples collected from caves containing bat and bird (swiftlet) populations are being processed by the Division of Mycotic Diseases, at the Center for Disease Control, Atlanta, Georgia. Preliminary results from 15 caves have been negative, thus a more precise technique will be utilised in further collections. Intradermal histoplasmin skin testing of cavers intends to identify the possibility of cave exploration as one source of Histoplasma capsulatum exposure.


Caesium-137 and Caesium-134 levels in soil in a tea plantation in Turkey after the chernobyl accident, 1989, Yesin T. , Cakir N. ,
Gamma-ray scintillation spectrometry has been used to measure the 137Cs and 134Cs levels and depth distributions in soil of a tea plantation in the Eastern Black Sea region in Turkey. Soil samples were collected in November 1987. The depth distribution was found to be exponential with [alpha] = 0.16 cm-1 and the exposure rate arising therefrom is calculated as 17.46 [mu]R/h over the ground surface

A MIDDLE PROTEROZOIC PALEOKARST UNCONFORMITY AND ASSOCIATED SEDIMENTARY-ROCKS, ELU BASIN, NORTHWEST CANADA, 1991, Pelechaty S. M. , James N. P. , Kerans C. , Grotzinger J. P. ,
A major palaeokarst erosion surface is developed within the middle Proterozoic Elu Basin, northwestern Canada. This palaeokarst is named the sub-Kanuyak unconformity and truncates the Parry Bay Formation, a sequence of shallow-marine dolostones that were deposited within a north-facing carbonate platform under a semi-arid climate. The sub-Kanuyak unconformity exhibits up to 90 m of local relief, and also formed under semi-arid conditions when Parry Bay dolostones were subaerially exposed during a relative sea-level drop of about 180 m. Caves and various karren developed within the meteoric vadose and phreatic zones. Their geometry, size and orientation were largely controlled by northwest- and northeast-trending antecedent joints, bedding, and lithology. Near-surface caves later collapsed forming valleys, and intervening towers or walls, and plains. Minor terra rossa formed on top of highs. Karstification was most pronounced in southern parts of Bathurst Inlet but decreased northward, probably reflecting varying lengths of exposure time along a north-dipping slope. The Kanuyak Formation is up to 65 m thick, and partially covers the underlying palaeokarst. It consists of six lithofacies: (i) breccia formed during collapse of caves, as reworked collapse breccia and regolith; (ii) conglomerate representing gravel-dominated braided-fluvial deposits; (iii) sandstone deposited as braided-fluvial and storm-dominated lacustrine deposits; (iv) interbedded sandstone, siltstone and mudstone of sheet flood origin; (v) dolostones formed from dolocretes and quiet-water lacustrine deposits; and (vi) red-beds representing intertidal-marine mudflat deposits. Rivers flowed toward the northwest and northeast within karst valleys and caves; lakes were also situated within valleys; marine mudflat sediments completely cover the palaeokarst to the north. A regional correlation of the sub-Kanuyak unconformity with the intra-Greenhorn Lakes disconformity within the Coppermine homocline suggests that similar styles of karstification occurred over an extensive region. The Elu Basin palaeokarst, however, was developed more landward, and was exposed for a longer period of time than the Coppermine homocline palaeokarst

GENERAL CENOZOIC EVOLUTION OF THE MALDIVES CARBONATE SYSTEM (EQUATORIAL INDIAN-OCEAN), 1992, Aubert O, Droxler Aw,
Analyses and interpretation of an industrial multi-channel seismic grid, a 2.3 km-deep industrial well (NMA-1) and two ODP (Sites 715 and 716), have generated new insights into the evolution of the Maldives carbonate system, Equatorial Indian Ocean. The present physiography of the Maldives Archipelago, a double chain of atolls delineating an internal basin, corresponds only to the latest phase of a long and dynamic evolution, far more complex than the simple vertical build-up of reef caps on top of thermally subsiding volcanic edifices. Through the Cenozoic evolution of the Maldives carbonate system, distinct phases of vertical growth (aggradation), exposure, regional or local drowning, and recovery of the shallow banks by lateral growth (progradation) have been recognized. The volcanic basement underlying the Maldives Archipelago is interpreted to be part of a volcanic ridge generated by the northern drift of the Indian plate on top of the hotspot of the island of Reunion. The volcanic basement recovered at well NMA-1 and ODP Site 715 has been radiometrically dated as 57.2 1.8 Ma (late Paleocene) by 40Ar-39Ar. Seismic and magnetic data indicate that this volcanic basement has been affected by a series of NNE-SSW trending subvertical faults, possibly associated with an early Eocene strike-slip motion along an old transform zone. The structural topography of the volcanic basement apprears to have dictated the initial geometry of the Eocene and early Oligocene Maldives carbonate system. Biostratigraphic analyses of samples, recovered by drilling in Site 715 and exploration well NMA-1, show that the Maldives shallow carbonate system was initiated during the early Eocene on top of what were originally subaerial volcanic edifices. The Eocene shallow carbonate sequence, directly overlying the volcanic basement at NMA-1, is dolomitized and remains neritic in nature, suggesting low subsidence rates until the early Oligocene. During this first phase of the Maldives carbonate system evolution, shallow carbonate facies aggraded on top of basement highs and thick deep-water periplatform sediments were deposited in some central seaways, precursors of the current wider internal basins. In the middle Oligocene, a plate reorganization of the equatorial Indian Ocean resulted in the segmentation of the hotspot trace and the spreading of the Maldives away from the transform zone. This plate reorganization resulted in increasing subsidence rates at NMA-1, interpreted to be associated with thermal cooling of the volcanic basement underlying the Maldives carbonate system. This middle Oligocene event also coincides with a regional irregular topographic surface, considered to represent a karst surface produced by a major low-stand. Deep-water carbonate facies, as seen in cuttings from NMA-1, overlie the shallow-water facies beneath the karst surface which can, therefore, be interpreted as a drowning unconformity. In the late Oligocene, following this regional deepening event, one single central basin developed, wider than its Eocene counterparts, and the current intraplatform basin was established. Since the early to middle Miocene, the shallow carbonate facies underwent a stage of local recovery by progradation of neritic environments towards the central basin. The simultaneous onset in the early middle Miocene of the monsoonal wind regime may explain the development of bidirectional slope progradations in the Maldives. During the late Miocene and the early Pliocene, several carbonate banks were locally drowned, whereas others (i.e. Male atoll) display well-developed lateral growth through margin progradations during the same interval. Differential carbonate productivity among the atolls could explain these diverse bank responses. High-frequency glacialeustatic sea-level fluctuations in the late Pliocene and Pleistocene resulted in periodic intervals of bank exposure and flooding, and developed the present-day physiography of atolls, with numerous faros along their rims and within their lagoons

PALUSTRINE CARBONATES AND THE FLORIDA EVERGLADES - TOWARDS AN EXPOSURE INDEX FOR THE FRESH-WATER ENVIRONMENT, 1992, Platt N. H. , Wright V. P. ,
Palustrine carbonates are shallow fresh-water deposits showing evidence of subaqueous deposition and subaerial exposure. These facies are common in the geological record. The intensity of modification is highly variable depending on the climate and the length of emergence. Palustrine limestones have previously been interpreted as marginal lacustrine deposits from fluctuating, low-salinity carbonate lakes, but several problems remain with existing facies models: 1) palustrine carbonates possess a lacustrine biota but commonly display fabrics similar to those of calcretes and peritidal carbonates; 2) the co-occurrence of calcrete horizons and karst-like cavities is somewhat unusual and appears to indicate contemporaneous carbonate precipitation and dissolution in the vadose zone; 3) the dominance of gray colors indicates water-saturation, apparently inconsistent with the evidence for strong desiccation overprint; 4) profundal lake deposits are generally absent from palustrine sequences, and sublittoral facies commonly make up only a small proportion of total thicknesses; 5) no good modem analogue has been identified for the palustrine environment. Analogy with the Florida Everglades suggests a re-interpretation of palustrine limestones, not as pedogenically modified lake margin facies but as the deposits of extensive, very shallow carbonate marshes. The distribution of environments in the Everglades is determined by the local hydrology, reflecting the control of seasonal water-level fluctuations and topography. Climate and topography were the main controls on deposition of ancient palustrine carbonates. As in peritidal sequences, aggradational cycles are capped by a range of lithologies (evaporites, desiccation and microkarst breccias, calcretes, lignite or coal horizons etc.), permitting interpretation of the climate. Careful analysis of lateral facies variations may permit reconstruction of subtle topography. Consideration of the Florida Everglades as a modem analogue for the palustrine environment has suggested the development of an exposure index for fresh-water carbonates

Results 1 to 15 of 139
You probably didn't submit anything to search for