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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 percolation; percolation water is 1. ground water moving slowly through the microfissure network of a limestone, most of which eventually joins a major cave conduit and flows more rapidly. in most environments percolation water enters the limestone through a soil cover. it is therefore high in carbon dioxide and has a major influence on limestone dissolution and later redeposition of calcite speleothems. percolation water accounts for most of the storage in a limestone aquifer, responds slowly to flooding in comparison to sinkhole water, and is normally of high enough quality to provide a drinking-water supply [9]. 2. the movement in laminar flow under hydrostatic pressure of water through the interconnected, saturated interstices of rock or soil, excluding movement through large openings such as caves and solution channels. 3. the downward movement of water through the unsaturated zone [22]. 4.the downward flow of water in saturated or nearly saturated porous medium at hydraulic gradients of the order of 1.0 or less [22]. 5. the movement of water through saturated interior pore space [16]. synonym: seepage water.?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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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 stable-isotope (Keyword) returned 75 results for the whole karstbase:
Showing 61 to 75 of 75
Modification and preservation of environmental signals in speleothems, 2006, Fairchild Ij, Smith Cl, Baker A, Fuller L, Spotl C, Mattey D, Mcdermott F, Eimp,
Speleothems are primarily studied in order to generate archives of climatic change and results have led to significant advances in identifying and dating major shifts in the climate system. However, the climatological meaning of many speleothem records cannot be interpreted unequivocally, this is particularly so for more subtle shifts and shorter time periods, but the use of multiple proxies and improving understanding of formation mechanisms offers a clear way forward. An explicit description of speleothem records as time series draws attention to the nature and importance of the signal filtering processes by which the weather, the seasons, and longer-term climatic and other environmental fluctuations become encoded in speleothems. We distinguish five sources of variation that influence speleothem geochemistry, i.e. atmospheric, vegetation/soil, karstic aquifer, primary speleothem crystal growth and secondary alteration, and give specific examples of their influence. The direct role of climate diminishes progressively through these five factors. We identify and review a number of processes identified in recent and current work that bear significantly on the conventional interpretation of speleothem records, for example: (1) speleothem geochemistry can vary seasonally and hence a research need is to establish the proportion of growth attributable to different seasons and whether this varies over time; (2) whereas there has traditionally been a focus on monthly mean delta O-18 data of atmospheric moisture, current work emphasizes the importance of understanding the synoptic processes that lead to characteristic isotope signals, since changing relative abundance of different weather types might control their variation on the longer-term; (3) the ecosystem and soil zone overlying the cave fundamentally imprint the carbon and trace element signals and can show characteristic variations with time; (4) new modelling on aquifer plumbing allows quantification of the effects of aquifer mixing; (5) recent work has emphasized the importance and seasonal variability Of CO2-degassing leading to calcite precipitation upflow of a depositional site on carbon isotope and trace element composition of speleothems; (6) although much is known about the chemical partitioning between water and stalagmites, variability in relation to crystal growth mechanisms and kinetics is a research frontier; (7) aragonite is susceptible to conversion to calcite with major loss of chemical information, but the controls on the rate of this process are obscure. Analytical factors are critical in generating high-resolution speleothem records. A variety of methods of trace element analysis is available, but standardization is a common problem with the most rapid methods. New stable isotope data on Irish stalagmite CC3 compares rapid laser-ablation techniques with the conventional analysis of micromilled powders and ion microprobe methods. A high degree of comparability between techniques for delta O-18 is found on the millimeter to centimeter scale, but a previously described high-amplitude oxygen isotope excursion around 8.3 ka is identified as an analytical artefact related to fractionation of the laser-analysis associated with sample cracking. High-frequency variability of not less than 0.5 parts per thousand may be an inherent feature of speleothem delta O-18 records. (c) 2005 Elsevier B.V. All rights reserved

Hydrocarbon Biomarkers in the Topla-Mezica Zinc-Lead Deposits, Northern Karavanke/Drau Range, Slovenia: Paleoenvironment at the Site of Ore Formation, 2006, Spangenberg Jorge E. , Herlec Ursos,
The Mississippi Valley-type zinc and lead deposits at Topla (250,150 metric tons (t) of ore grading 10 wt % Zn and 3.3 wt % Pb) and Me[z]ica (19 million metric tons (Mt) of ore grading 5.3 wt % Pb and 2.7 wt % Zn) occur within the Middle to Upper Triassic platform carbonate rocks of the northern Karavanke/Drau Range geotectonic units of the Eastern Alps, Slovenia. The ore and host rocks of these deposits have been investigated by a combination of inorganic and organic geochemical methods to determine major, trace, and rare earth element (REE) concentrations, hydrocarbon distribution, and stable isotope ratios of carbonates, kerogen, extractable organic matter, and individual hydrocarbons. These data combined with sedimentological evidence provide insight into the paleoenvironmental conditions at the site of ore formation. The carbonate isotope composition, the REE patterns, and the distribution of hydrocarbon biomarkers (normal alkanes and steranes) suggest a marine depositional environment. At Topla, a relatively high concentration of redox sensitive trace elements (V, Mo, U) in the host dolostones and REE patterns parallel to that of the North American shale composite suggest that sediments were deposited in a reducing environment. Anoxic conditions enhanced the preservation of organic matter and resulted in relatively higher total organic carbon contents (up to 0.4 wt %). The isotopic composition of the kerogen ({delta}13Ckerogen = -29.4 to -25.0{per thousand}, {delta}15Nkerogen = -13.6 to 6.8{per thousand}) suggests that marine algae and/or bacteria were the main source of organic carbon with a very minor contribution from detrital continental plants and a varying degree of alteration. Extractable organic matter from Topla ore is generally depleted in 13C compared to the associated kerogen, which is consistent with an indigenous source of the bitumens. The mineralization correlates with {delta}15Nkerogen values around 0 per mil, 13C depleted kerogen, 13C enriched n-heptadecane, and relatively high concentrations of bacterial hydrocarbon biomarkers, indicating a high cyanobacterial biomass at the site of ore formation. Abundant dissimilatory sulfate-reducing bacteria, feeding on the cyanobacterial remains, led to accumulation of biogenic H2S in the pore water of the sediments. This biogenic H2S was mainly incorporated into sedimentary organic matter and diagenetic pyrite. Higher bacterial activity at the ore site also is indicated by specific concentration ratios of hydrocarbons, which are roughly correlated with total Pb plus Zn contents. This correlation is consistent with mixing of hydrothermal metal-rich fluids and local bacteriogenic sulfide sulfur. The new geochemical data provide supporting evidence that Topla is a low-temperature Mississippi Valley-type deposit formed in an anoxic supratidal saline to hypersaline environment. A laminated cyanobacterial mat, with abundant sulfate-reducing bacteria was the main site of sulfate reduction

Late Holocene drought responsible for the collapse of Old World civilizations is recorded in an Italian cave flowstone, 2006, Drysdale R, Zanchetta G, Hellstrom J, Maas R, Fallick A, Pickett M, Cartwright I, Piccini L,
A severe drought in parts of low-latitude northeastern Africa and southwestern Asia [~]4200 yr ago caused major disruption to ancient civilizations. Stable isotope, trace element, and organic fluorescence data from a calcite flowstone collected from the well-watered Alpi Apuane karst of central-western Italy indicate that the climatic event responsible for this drought was also recorded in mid-latitude Europe. Although the timing of this event coincides with an episode of increased ice-rafted debris to the subpolar North Atlantic, the regional ocean-atmosphere response seems atypical of similar Holocene ice-rafting events. Furthermore, comparison of the flowstone data with other regional proxies suggests that the most extreme part of the dry spell occurred toward the end of a longer-term climate anomaly

Large kinetic isotope effects in modern speleothems, 2006, Mickler Patrick J. , Stern Libby A. , Banner Jay L. ,
The application of stable isotopes in speleothem records requires an understanding of the extent to which speleothem calcite isotopic compositions reflect the compositions of the cave waters from which they precipitate. To test for equilibrium precipitation, modern speleothem calcite was grown on glass plates, so that the carbon and oxygen isotope composition of the calcite and the water from which it precipitated could be directly compared. The plates were placed on the tops of three actively growing stalagmites that occupy a 1 m2 area in Harrison's Cave, Barbados, West Indies. Only some of the plate {delta}13C values and none of the plate {delta}18O values correspond to equilibrium values, indicating significant kinetic isotope effects during speleothem calcite growth. We investigate herein mechanisms that may account for the kinetic isotope effects. On each plate, speleothem calcite was deposited with distinct {delta}18O and {delta}13C compositions that increase progressively away from the growth axis, with up to 6.6{per thousand} 13C and 1.7{per thousand} 18O enrichments. The positive {delta}13C versus {delta}18O trends are likely a result of 18O and 13C Rayleigh-distillation enrichment in the HCO3- reservoir owing to progressive CO2 degassing and CaCO3 precipitation. The magnitude of the {delta}13C versus {delta}18O slope is likely controlled by the extent to which CO2 hydration-hydroxylation reactions buffer the oxygen isotope composition of the HCO3- reservoir during calcite precipitation. Complete oxygen isotopic buffering of the HCO3- reservoir by CO2 hydration-hydroxylation reactions will produce a vertical {delta}13C versus {delta}18O slope in calcite sampled along a growth layer. As oxygen isotope buffering of the HCO3- reservoir decreases to no buffering, the {delta}13C versus {delta}18O slope in calcite sampled along a growth layer will decrease from vertical to 0.52 at the cave temperature. In this study, modern speleothem calcite sampled along the growth layer produced a {delta}13C versus {delta}18O slope of 3.9, indicating incomplete oxygen isotope buffering of the HCO3- reservoir during calcite precipitation. Both modern and Holocene speleothem calcite from Barbados, sampled temporally along the growth axis, shows similar positive {delta}13C versus {delta}18O slopes. These results, along with the spatial variations in glass plate calcite carbon and oxygen isotope compositions, suggest that the isotopic composition of the Holocene speleothems is in part controlled by non-equilibrium isotope effects. In addition, there is a correlation between stalactite length and oxygen and carbon isotope ratios of calcite precipitated on the corresponding stalagmite and glass plate, which may be due to 13C and 18 O enrichment of the HCO3- reservoir during CO2 degassing-calcite precipitation along the overhanging stalactite. We compiled 165 published speleothem stable isotope records with a global distribution and found that most of these records show a positive covariation between {delta}13C and {delta}18O values. Speleothem stable isotope records may be influenced by kinetic isotope effects such that temperature-controlled equilibrium fractionation models alone cannot directly explain the significance of the variations in these records. Advancing the interpretation of these records requires the calibration of cave environmental conditions with the non-equilibrium isotope effects that cause {delta}13C and {delta}18O covariations in speleothems

Quantification of karst aquifer discharge components during storm events through end-member mixing analysis using natural chemistry and stable isotopes as tracers, 2006, Daniel Hd, Alexander Ec, Metka P, Janja Ke, Janko U, Sonja L, Willibald S,

Dolomite formation in breccias at the Musandam Platform border, Northern Oman Mountains, United Arab Emirates, 2006, Breesch L, Swennen R, Vincent B,
The presence of dolomite breccia patches along Wadi Batha Mahani suggests large-scale fluid flow causing dolomite formation. The controls on dolomitization have been studied, using petrography and geochemistry. Dolomitization was mainly controlled by brecciation and the nearby Hagab thrust. Breccias formed as subaerial scree deposits, with clay infill from dissolved platform limestones, during Early Cretaceous emergence. Cathodoluminescence of the dolostones indicates dolomitization took place in two phases. First, fine-crystalline planar-s dolomite replaced the breccias. Later, these dolomites were recrystallized by larger nonplanar dolomites. The stable isotope trend towards depleted values (delta O-18: -2.7 parts per thousand to - 10.2 parts per thousand VPDB and delta C-13: -0.6 parts per thousand to -8.9 parts per thousand VPDB), caused by mixing dolomite types during sampling, indicates type 2 dolomites were formed by hot fluids. Microthermometry of quartz cements and karst veins, post-dating dolomites, also yielded high temperatures. Hot formation waters which ascended along the Hagab thrust are invoked to explain type 2 dolomitization, silicification and hydrothermal karstification. (C) 2006 Elsevier B.V, All rights reserved

Chronology and paleoenvironment of Marine Isotope Stage 3 from two high-elevation speleothems, Austrian Alps, 2006, Spotl Christoph, Mangini Augusto, Richards David A. ,
A new high-resolution stable isotope record from the alpine Kleegruben Cave (2165 m, Central Alps) is presented. This record largely duplicates a previously reported speleothem record from this site. High-precision U-series thermal ionization mass spectrometry dates constrain the growth history of this new sample (56-48 ka) to the Marine Isotope Stage (MIS) 3. Both stalagmites reveal highly similar variations in O isotopes that can be directly compared to O isotope variability associated with Dansgaard-Oeschger interstadials recorded in the Greenland ice cores (Greenland Interstadials, GIS). Based on the new record we refine our previous age assignments of the GIS during this time interval, i.e. GIS 15b at 55.7 ka, GIS 15a at 55.3 ka, onset (mid-point) of the prominent GIS 14 at 54.5 yr and onset of GIS 12 at ~48 ka. The overall uncertainties associated with these ages are 0.1-0.3 ka. The timing of these Dansgaard-Oeschger interstadials is within 0.2 ka of the newly proposed GRIP.SFCP04 timescale.The age data for both Kleegruben stalagmites demonstrate that liquid water was at least seasonally present in the shallow sub-surface allowing calcite precipitation to continue even during stadials of MIS 3. Given the present-day low temperature (.4 [deg]C) we propose that these unusual speleothems formed in a karst system overlain by a warm-based glacier

Lower Eocene carbonate cemented chimneys (Varna, NE Bulgaria): Formation mechanisms and the (a)biological mediation of chimney growth?, 2006, De Boever E, Swennen R, Dimitrov L,
In the area of Pobiti Kamani (Varna, northeast Bulgaria), massive carbonate cemented columns ('chimneys', up to 1.5 m diameter and 8 m high) and horizontal interbeds (2 within loose Lower Eocene sands. Field observations and petrographical and stable isotope geochemical characterisation of four studied locations reveal a relationship between these structures and processes of ancient hydrocarbon seepage. Column and interbed structures both consist of similar well-sorted silt- to sand-sized nummulitic host sediments, predominantly cemented by early diagenetic, low-magnesium calcite. Filamentous textures, about 10 [mu]m in diameter and 80-650 [mu]m long, are only locally detected within interparticle calcite cement of columns. Column samples from two sites reveal a similar, linear and inverse covariant trend of [delta]13C-[delta]18O values, which was interpreted as a mixing trend between two end member fluid/precipitation conditions, i.e. (1) a methane- and/or higher hydrocarbon-derived carbon member characterised by [delta]13C values as low as -[no-break space]43[per mille sign] and marine controlled precipitation conditions with [delta]18O of - 1 0.5[per mille sign] V-PDB and (2) a member with less contribution of methane which was mixed most likely with less depleted carbon sources explaining [delta]13C values ranging up to - 8[per mille sign] V-PDB. The corresponding, depleted [delta]18O values, with many samples clustering around - 8[per mille sign] V-PDB, are interpreted in terms of precipitation at elevated temperatures. This suggests the venting system was not a true 'cold' seep, sensu stricto. Furthermore, column cross-transects often document an internal pattern consisting of (concentric) zones with distinct isotopic signatures, which vary between the two end members. The mixing and internal pattern of column isotopic data, together with petrographical observations, are qualitatively interpreted as evidence of alternating precipitation conditions, controlled by varying seepage rates of a single fluid source at depth, during build-up of individual chimney pipes near the sediment surface. Based on several field observations, migration of the hydrocarbon-charged fluids in Lower Eocene times was possibly channelled along NE oriented faults. Isotopic signatures of calcite cemented horizontal interbeds, with depleted [delta]18O ratios as low as - 8.88[per mille sign] V-PDB and variable [delta]13C (- 1[per mille sign] to - 16[per mille sign], mainly around - 5[per mille sign] to - 7[per mille sign]) suggest that ascending fluids contributed to their cementation or resetted the calcite cement isotopic signature, predominantly during periods of active seepage of warmer fluids. Only few petrographical (and preliminary lipid-biomarker) evidence has been found, pointing to the presence or possibly former activity of microbiota, involved in carbon cycling and calcite precipitation, typical of cold seep settings. This may result from diagenetic alteration of organic components. However, considering the processes of chimney formation, a cementation process, governed by the inorganic oxidation of hydrocarbons in which interstitial oxygen is rapidly consumed without bacterial mediation, is considered

Reconstruction of the paleoenvironmental changes around the Miocene-Pliocene boundary along a West-East transect across the Mediterranean, 2006, Pierre Catherine, Caruso Antonio, Blancvalleron Marie Madeleine, Rouchy Jean Marie, Orzsagsperber Fabienne,
In order to reconstruct the environmental changes at the end of the Messinian salinity crisis, a multidisciplinary study has been carried out with a high sampling resolution of the late Messinian-early Zanclean (Zone MPl 1) sediments along a West-East Mediterranean transect. The studied examples comprise sections from southern Spain (Vera/Almanzora), Balearic Basin (ODP Site 975), Tyrrhenian Basin (ODP Site 974), Sicily (Eraclea Minoa), Zakynthos (Kalamaki), Corfu (Aghios Stefanos), Crete (Aghios Vlasis). Previously analyzed sections from the Levantine Basin (Cyprus and ODP Sites 968 and 969) are used for comparison. The sections have been correlated using planktonic foraminiferal assemblages, sedimentological and stable isotope variations, and compared to the astronomical cyclicity defined in the Miocene-Pliocene boundary stratotype of Eraclea Minoa, Sicily. Variations of CaCO3 content, stable isotopes of carbonates ([delta]18O, [delta]13C), and foraminiferal assemblages indicate similar environmental transition at the Miocene-Pliocene boundary in all of the investigated sections.The latest Messinian deposits are barren of fossils or characterized by only reworked planktonic foraminifers, except for the sporadic presence of Ammonia tepida, brackish or lacustrine ostracods and brackish mollusks typical of the 'Lago-Mare' facies. The oxygen and carbon isotopic compositions of carbonates usually exhibit large variations with dominantly low [delta] values indicating freshwater dilution. The earliest Pliocene (MPl 1, cycle 1) shows a rapid and progressive increase of the [delta]18O values, which indicates the restoration of marine conditions after the Lago-Mare event. Normal marine environments were definitely established and stabilized at the top of cycle 1.These data confirm that the inflow of marine waters occurred contemporaneously within the whole Mediterranean at the base of Pliocene, although stable marine conditions occurred only about 20[no-break space]kyrs later

Pleistocene speleothems of Mallorca: implications for palaeoclimate and carbonate diagenesis in mixing zones, 2006, Csoma Ae, Goldstein Rh, Pomar L,
The Pleistocene speleothems of Sa Bassa Blanca cave, Mallorca, are excellent indicators of palaeoclimate variations, and are samples that allow evaluation of the products and processes of mixing-zone diagenesis in an open-water cave system. Integrated stratigraphic, petrographic and geochemical data from a horizontal core of speleothem identified two main origins for speleothem precipitates: meteoric-marine mixing zone and meteoric-vadose zone. Mixing-zone precipitates formed at and just below the water-air interface of cave pools during interglacial times, when the cave was flooded as a result of highstand sea-level. Mixing-zone precipitates include bladed and dendritic high-Mg calcite, microporous-bladed calcite with variable Mg content, and acicular aragonite; their presence suggests that calcium-carbonate cementation is significant in the studied mixing-zone system. Fluid inclusion salinities, delta(13)C and delta(18)O compositions of the mixing-zone precipitates suggest that mixing ratio was not the primary control on whether precipitation or dissolution occurred, rather, the proximity to the water table and degassing of CO2 at the interface, were the major controls on precipitation. Thus, simple two-end-member mixing models may apply only in mixing zones well below the water table. Meteoric-vadose speleothems include calcite and high-Mg calcite with columnar and bladed morphologies. Vadose speleothems precipitated during glacial stages when sea level was lower than present. Progressive increase in delta(13)C and delta(18)O of the vadose speleothems resulted from cooling temperatures and more positive seawater delta(18)O associated with glacial buildup. Such covariation could be considered as a valid alternative to models predicting invariant delta(18)O and highly variable delta(13)C in meteoric calcite. Glacio-eustatic oscillations of sea-level are recorded as alternating vadose and mixing-zone speleothems. Short-term climatic variations are recorded as alternating aragonite and calcite speleothems precipitated in the mixing zone. Fluid-inclusion and stable-isotope data suggest that aragonite, as opposed to calcite, precipitated during times of reduced meteoric recharge

Stable isotopes in aqueous sulphate as tracers of natural and contaminant sulphate sources: a reconnaissance study of the Xingwen karst aquifer, Sichuan, China, 2007, Bottrell Sh,
Isotopic compositions of sulphate ({delta}18O and {delta}34S) have been analysed in groundwaters from a karst aquifer in Xingwen, China to assess their use as indigenous tracers of different pollutant sulphate sources. Sulphate {delta}18O is highly effective at distinguishing sulphate from atmospheric acid rain' sources (higher {delta}18O values) from sulphate produced by aqueous pyrite oxidation (natural or acid mine drainage), which always has lower {delta}18O. The range of sulphate {delta}34S produced by aqueous oxidation of different pyrite sources is sufficiently wide to enable different natural and pollutant sulphate sources to be distinguished. Despite the fact that streams containing processing fines and pyrite mine drainage both derive sulphate from oxidation of ore materials, there is still a clear distinction in their sulphate {delta}34S. A combination of sulphur and oxygen isotopic measurements is thus highly effective at discriminating between all the sulphate sources to the karst aquifer and this indigenous tracer provides a powerful tool for assessing the impact of acid mine drainage on karst groundwater

Stalagmite stable isotope record of recent tropical cyclone events, 2007, Frappier Ab, Sahagian D, Carpenter Sj, Gonzalez La, Frappier Br,
We present a 23 yr stalagmite record (1977-2000) of oxygen isotope variation, associated with 11 tropical cyclones (TCs), from Actun Tunichil Muknal cave in central Belize. High-resolution microsampling yielded a record of monthly to weekly temporal resolution that contains abrupt decreases (negative excursions) in calcite {delta}18O values that correspond with recent TC rain events nearby. A logistic discriminant model reliably identified TC proxy signals using the measurable parameters {delta}18O and {delta}13C values, and single point changes in {delta}18O value. The logistic model correctly identified 80% of excursions as TC events and incorrectly classified only 1 of nearly 1200 nonstorm sampling points. In addition to enabling high-resolution TC frequency reconstruction, this geologic proxy also provides information about the intensity of individual TCs. A multiple regression predicted TC intensity (R2 = 0.465, p = 0.034) using sampling frequency and excursion amplitude. Consistent with previous low-resolution studies, we found that the decadal average {delta}18O value was lower during the 1990s when several TCs produced rainfall in the area, but higher during the 1980s when only one TC struck. Longer, accurately dated, high-resolution speleothem stable isotope records may be a useful new tool for paleotempestology, to clarify associations between highly variable TC activity and the dynamic range of Quaternary climate

Textural, Elemental, and Isotopic Characteristics of Pleistocene Phreatic Cave Deposits (Jabal Madar, Oman), 2007, Immenhauser Adrian, Dublyansky Yuri V. , Verwer Klaas, Fleitman Dominik, Pashenko Serguei E. ,
Two main types of karst formation are commonly known: the surficial meteoric one and the subsurface (hypogenic) karst, which can be related to both carbonic (H2CO3) and sulfuric (H2S) acids. This paper documents evidence for a third, CO2-regime related, type of karst that is less commonly described. Petrographic and geochemical properties of exhumed Pleistocene phreatic cave deposits from the diapiric Jabal Madar dome in northern Oman are documented and discussed in a process-oriented context. These calcites form at the interface between two fundamentally different diagenetic and hydrogeological domains: the deep-seated, hydrothermal and the near-surficial, meteoric-vadose one. Four calcite phases are recognized: (i) acicular, (ii) blocky to stubby elongated, (iii) proto-palisade, and (iv) macro-columnar calcites. The macro-columnar calcites, forming the last stage of precipitation, are conspicuous due to their cyclical red zonation, and they form the main (geochemical) focus of this study. Fluid inclusion data point to fluid temperatures of between 30 to 50{degrees}C (monophase liquid inclusions) and elevated salinities (1.6 to 7.3 wt.% NaCl equivalent). Low carbon-isotope data (-8 to -9{per thousand}) are in agreement with the influx of soil-zone CO2 whereas decreasing {delta}18O (-15{per thousand}) values might point to mixing of saline hydrothermal and 18O depleted, meteoric freshwater, i.e., two fluid sources. Trace-element and stable-isotope data shift between the different cement phases and vary cyclically across the red zoning in macro-columnar calcites. With respect to the intra-crystal variability, these patterns are perhaps best explained in the context of redox potential. Two interpretations are presented; the one favored here suggests that the cyclical red zoning in macro-columnar calcites is controlled by Pleistocene monsoonal climate patterns

Stable isotope variations in stalagmites from northwestern Sweden document climate and environmental changes during the early Holocene, 2007, Sundqvist H. S. , Holmgren K. , Lauritzen S. E. ,
This paper presents two early Holocene (9.6-5.9 ka BP) high-resolution stable isotope records of stalagmites from two caves in northwestern Sweden (Korallgrottan and Labyrintgrottan). Close similarities between the Swedish records and a previously presented Norwegian stalagmite oxygen isotope record emphasize the potential of Scandinavian stalagmites to provide high-resolution regional palaeoclimatic information. The stable oxygen isotope records are interpreted to reflect the temperature evolution during the early Holocene with a gradual warming from c. 9.6 ka BP, interrupted by cooler conditions at 8.5-8.0 ka BP. The results indicate that the cooler conditions were driven by two to three abrupt cold events rather than one 8.2 event' only. Except for these cold events the stalagmite oxygen isotope records show that temperatures in northwestern Sweden were warmer than today between 9.6 and 5.9 ka BP and that during this period the interval between 7.8 and 5.9 ka BP seems to have been the warmest. The high-amplitude changes in the stable carbon isotope record of Labyrintgrottan are proposed to reflect changes in local vegetation. The area above Labyrintgrottan was most likely covered by much denser vegetation than today at the time of stalagmite growth (9.5-7.5 ka BP) and was -unlike today -probably situated below the local tree limit between 9.0 and 8.0 ka BP

MANAGING AQUIFER RECHARGE (MAR): ASSESSMENT OF GROUNDWATER RESOURCES IN THE SAND, 2007, Kim Thoa Nguyen Thi, Giuseppe Arduino, Paolo Bono, Nguyen Van Giang, Phan Thi Kim Van, Bui Tran Vuong, Dinh Thi Bich Lieu, Brun Clarissa, Chiara Fiori, Fabrizio Gherardi, Francesca Zucco
Extensive geophysical, hydrological and isotopic investigations, including drilling campaigns, long term pumping tests and continuous monitoring of ground water levels in 4 monitoring wells, show that the sand dunes formation is characterized by the occurrence of an unconfined porous aquifer, of variable thickness (40 to 60 m), emerging at ground level in depressed morphological areas (20 to 30 m a.s.l.) where it forms intradune wetlands or natural reservoirs (lakes), and discharging directly to the sea through single springs (up to 200 l/s), linear springs and mostly by diffuse seepage along the shoreline (approximate discharge equal to 30 l/s per km). Hydrochemical and isotopic characterization of surface and groundwater in different periods, shows that the sand dunes aquifers, with electrical conductivity ranging from 50 to 500 μS/cm, are composed of different water types, characterized by complex mixing processes. The site chosen for the artificial recharge, where a 162 days pumping test has been carried out, proved that the use of the bank filtration technique has considerably improved the quality of water, originally highly contaminated by colibacteria. The well field developed within the present project is now capable of supplying 220 m3/day of good water quality to the Hong Phong community, recurrently affected by severe droughts. This project is part of UNESCO-IHP (International Hydrological Programme) and IMET (Italian Ministry for the Environment and Territory) Water Programme for Africa, Arid and Water Scarce zone - Viet Nam component funded by IMET. Funds for the Viet Nam project were also made available from the Vietnamese Government, and from ICSU, the International Council for Science and UNESCO Office Jakarta.

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