MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology

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. ...

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 bed, upper confining is impermeable bed overlying an aquifer [16].?

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.
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;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for ra-226 (Keyword) returned 3 results for the whole karstbase:
Analysis of karst tufa from Guangxi, China, 2003, Franciskovicbilinski S, Bilinski H, Barisic D, Horvatincic N, Yuan Dx,
The paper presents an analysis of characteristic karst tufa from Guangxi, China, which has not been studied before. A comparison with tufa from Dinaric Karst of Croatia is discussed in view of the C-type climate. The major mineral is calcite. Minor minerals are quartz and dolomite, depending on location. The content of calcium carbonate varies from 65% to 92%, and that of magnesium carbonate from 0.03% to 1.77%. Among other elements, the most abundant are Fe, from 0.02% to 1.50%, and Ti, from 0.15% to 0.27%. Many other trace elements (V, Cr, Mn, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Hg and Pb) are also present. Specific activity of radionuclides K-40, Th-232, Cs-137, Ra-226 and U-238 varies from sample to sample. Concentration of U in tufa is close to that reported for sedimentary carbonate. Low concentration Of Cs-137 indicates that this part of the world was not exposed to nuclear explosions. The concentration of Ra-226 is the highest in Mashan County. The ratio U-238/Ra-226 (0.21-0.71) in tufa from Mashan County is significantly lower than the theoretical value of 1. In 5 of the 11 studied samples, stable isotopes delta(13)C and delta(18)O were analyzed. They were dated by means of the C-14 method. One tufa sample originated in the Pleistocene and the others in the Holocene. Because all of the tufa samples contain traces of Na and K, and K < Na, the tufa from Guangxi belong to the CO2-outgassing 'N' type according to the classification of Liu and He (1994)

Characterization of tufa from the Dinaric Karst of Croatia: mineralogy, geochemistry and discussion of climate conditions, 2004, Franciskovicbilinski S, Barisic D, Vertacnik A, Bilinski H, Prohic E,
Tufa deposits from four separate occurrences in the Dinaric Karst of Croatia were characterized with respect to mineralogy, geochemistry and activity of radionuclides. Three of the specimens are of Holocene age, formed during Atlantic, Subboreal and present climate. Two locations (Plitvice Lakes and Krka River) have previously been studied. Two locations (Mreznica and Slunjcica rivers) have not attracted scientific research yet. The major mineral in tufa is calcite. Minor minerals are quartz and dolomite, depending on location. Geochemistry of selected stream sediments (f <63 mum) from the Dinaric Karst was presented for comparison with tufa. Provided statistically significant number of samples studied, the ratios U-238/Ra-226, U-238/Th-232 and Cs-137 may provide tighter constraints on the paleoenvironment. It is suggested to be used in comparison of different world tufas. In general terms it is discussed a hypothesis that relates the occurrence of tufas to atmospheric pCO(2) and climate conditions. In addition, the needs for future multidisciplinary research on tufa formation are discussed, because there are several other important parameters dependent on climate, which still have to be studied

On Ra-226 and Rn-222 concentrations in the brackish waters of coastal aquifers: lab-investigations and confirmation in the carbonate aquifer of Brindisi (Italy), 2005, Spizzico M. , Sciannamblo D. ,
The ground waters circulating in the Apulian mesozoic carbonate aquifer, of coastal type, show high concentrations of Rn-222 everywhere. Considering their variation during the different phases of a hydrological year, such high concentration values can reach activity of 20 Bq/L, in the more internal zones of the aquifer. Moreover, it is often observed that, in correspondence of wells and springs nearest the coast, the concentrations of radioactive gas reach values greater than 400 Bq/L and vary considerably during the course of a day and with withdrawals. The research carried out over the last few years, has confirmed that Ra-226 and Rn-222 concentrations in the karst groundwater of Apulia, are mainly related to the occurrence of 'Terra Rossa' inside the aquifer and the capacity of these paleosols to fix the salts of Ra-226 coming from the dissolution of the calcareous and calcareous-dolomitic rocks. This paper shows the results of the analysis performed to define Rn-222 increase in the brackish waters that come in contact with carbonate rocks and 'terra rossa'. It also indicates the results of surveys performed in a coastal zone with well-known hydrogeological features. The controls performed during one hydrological year, have confirmed the relationships between the salt content of the ground waters and the enrichment of Rn-222 and have highlighted that the manner of increase of this radioisotope is related to cases of ionic exchange and adsorption regulated by the dynamics of marine intrusion

Results 1 to 3 of 3
You probably didn't submit anything to search for