KarstBase a bibliography database in karst and cave science.
Featured articles from Cave & Karst Science Journals
Characterization of minothems at Libiola (NW Italy): morphological, mineralogical, and geochemical study, Carbone Cristina; Dinelli Enrico; De Waele Jo
Chemistry and Karst, White, William B.
The karst paradigm: changes, trends and perspectives, Klimchouk, Alexander
Long-term erosion rate measurements in gypsum caves of Sorbas (SE Spain) by the Micro-Erosion Meter method, Sanna, Laura; De Waele, Jo; Calaforra, José Maria; Forti, Paolo
The use of damaged speleothems and in situ fault displacement monitoring to characterise active tectonic structures: an example from Zapadni Cave, Czech Republic , Briestensky, Milos; Stemberk, Josef; Rowberry, Matt D.;
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;
Featured article from geoscience journal
Rapid Communications in Mass Spectrometry/Rapid Commun. Mass Spectrom., 2010, Issue 24, p. 3521-3526
Empirical equations for the temperature dependence of calcite-water oxygen isotope fractionation from 10 to 708C
Demeґny A. , Kele S. , Sikloґsy Z.
Abstract:
Although the temperature dependence of calcite-water oxygen isotope fractionation seems to have been well established by numerous empirical, experimental and theoretical studies, it is still being discussed, especially due to the demand for increased accuracy of paleotemperature calculations. Experimentally determined equations are available and have been verified by theoretical calculations (considered as representative of isotopic equilibrium); however, many natural formations do not seem to follow these relationships implying either that existing fractionation equations should be revised, or that carbonate deposits are seriously affected by kinetic and solution chemistry effects, or late-stage alterations. In order to test if existing fractionation-temperature relationships can be used for natural deposits, we have studied calcite formations precipitated in various environments by means of stable isotope mass spectrometry: travertines (freshwater limestones) precipitating from hot and warm waters in open-air or quasi-closed environments, as well as cave deposits formed in closed systems. Physical and chemical parameters as well as oxygen isotope composition of water were monitored for all the investigated sites. Measuring precipitation temperatures along with oxygen isotope compositions of waters and calcites yielded empirical environment-specific fractionation– temperature equations: [1] 1000 _ lnaј17599/T – 29.64 [for travertines with a temperature range of 30 to 70-C] and [2] 1000 _ lnaј17500/T – 29.89 [for cave deposits for the range 10 to 25-C]. Finally, based on the comparison of literature data and our results, the use of distinct calcite-water oxygen isotopic fractionation relationships and application strategies to obtain the most reliable paleoclimate information are evaluated.
Although the temperature dependence of calcite-water oxygen isotope fractionation seems to have been well established by numerous empirical, experimental and theoretical studies, it is still being discussed, especially due to the demand for increased accuracy of paleotemperature calculations. Experimentally determined equations are available and have been verified by theoretical calculations (considered as representative of isotopic equilibrium); however, many natural formations do not seem to follow these relationships implying either that existing fractionation equations should be revised, or that carbonate deposits are seriously affected by kinetic and solution chemistry effects, or late-stage alterations. In order to test if existing fractionation-temperature relationships can be used for natural deposits, we have studied calcite formations precipitated in various environments by means of stable isotope mass spectrometry: travertines (freshwater limestones) precipitating from hot and warm waters in open-air or quasi-closed environments, as well as cave deposits formed in closed systems. Physical and chemical parameters as well as oxygen isotope composition of water were monitored for all the investigated sites. Measuring precipitation temperatures along with oxygen isotope compositions of waters and calcites yielded empirical environment-specific fractionation– temperature equations: [1] 1000 _ lnaј17599/T – 29.64 [for travertines with a temperature range of 30 to 70-C] and [2] 1000 _ lnaј17500/T – 29.89 [for cave deposits for the range 10 to 25-C]. Finally, based on the comparison of literature data and our results, the use of distinct calcite-water oxygen isotopic fractionation relationships and application strategies to obtain the most reliable paleoclimate information are evaluated.