Showing papers on "Environmental isotopes published in 1993"
434 citations
209 citations
TL;DR: In this paper, available δ11B data of a variety of natural fluid and solid samples from different geological environments are compiled and some of the most relevant aspects, including possible tracer applications of boron-isotope geochemistry, are summarized.
Abstract: The large relative mass difference between the two stable isotopes of boron, 10B and 11B, and the high geochemical reactivity of boron lead to significant isotope fractionation by natural processes. Published δ11B values (relative to the NBS SRM-951 standard) span a wide range of ≈ 90‰. The lowest δ11B values around — 30‰ are reported for non-marine evaporite minerals and certain tourmalines. The most 11B-enriched reservoir known to date are brines from Australian salt lakes and the Dead Sea of Israel with δ11B values up to +59‰. Dissolved boron in present-day seawater has a constant world-wide δ11B value of + 39.5‰. In this paper, available δ11B data of a variety of natural fluid and solid samples from different geological environments are compiled and some of the most relevant aspects, including possible tracer applications of boron-isotope geochemistry, are summarized.
206 citations
Book•
01 Jan 1993
TL;DR: In this article, the authors discuss the distribution and fractionation of isotopes in the environment: principles of isotopic fractionation radiocarbon stable isotopes stable isotope - case studies isotopic records of the environment.
Abstract: Part 1 Introduction: radioactive and stable isotopes radiation. Part 2 Experimental isotope additions: tracer experiments general considerations in isotope experiments isotope flux experiments isotope rate measurements. Part 3 Distribution and fractionation of isotopes in the environment: principles of isotopic fractionation radiocarbon stable isotopes stable isotopes - case studies isotopic records of the environment. Part 4 Safety and laboratory procedure: biological consequences of radioisotope exposure radiosotope handling and safety. Part 5 Measurement techniques: stable isotopes radioisotopes.
51 citations
TL;DR: In this article, the isotope results show that most of the shallow groundwaters near the Sukri river course have δD, δ18O enriched compared to those away from the river course and have tritium values of 5-20 TU showing that they are possibly recharged from river channels during flash floods.
30 citations
24 citations
15 Sep 1993-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The status and capabilities of the isotope enrichment facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities are described in this paper, where the authors highlight the importance of isotope products in the fabrication of nuclear targets and the subsequent production of special radionuclides.
Abstract: Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL. This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities.
14 citations
TL;DR: In this article, the authors consider deep waters from horizons located under the Baltic-Sea bottom and show that these waters show their glacial origin since they have significantly low values (δ18O from −14 to −11 whereas the modern groundwaters in Gdansk area have −10%0).
Abstract: In this paper we consider deep waters from horizons located under the Baltic-Sea bottom. The samples were taken twice from wells bored in Hel peninsula. The δ18O and δD values of these waters show their glacial origin since they have significantly low values (δ18O from −14 to −11 whereas the modern groundwaters in Gdansk area have −10%0). In contrast to surface waters the sulphates dissolved in these deep waters have rather high and uniform δ18O values which are correlated with δ18O of H2O but not correlated with δ34S. The isotope patterns may be explained assuming that the waters are very old, in which the slow process of oxygen isotope exchange at low temperatures, but extended in time, could enrich the sulphate in heavier oxygen isotopes.
10 citations
TL;DR: The results obtained results do not indicate the presence of paleowaters; rather all groundwaters in the basin are found to be of meteoric origin as both ΔD and Δ18O values of the samples, plotted in the conventional way, align with the meteoric water line (MWL).
Abstract: The area of the Bida basin is lacking in essential data for effective groundwater management. Hydrological studies using environmental isotopes (2H,3H,13C,18O) were carried out in the basin during the 1987–1988 hydrological year on samples of rainfall, streams, springs, and groundwater. The results obtained results do not indicate the presence of paleowaters; rather all groundwaters in the basin are found to be of meteoric origin as bothδD andδ18O values of the samples, plotted in the conventional way, align with the meteoric water line (MWL). Moreover, these data show the deeper, and apparently older, groundwater to be more depleted in the heavy stable isotopes than the shallower, relatively younger groundwaters, indicating recharge under cooler climatic conditions for the former. Measured tritium values range from 0.7 to 23.8 TU and show a variation with both depth and lithology, while at the same time indicating that active recent recharge is taking place basin-wide. The few13C data available were used to illustrate the effect of pumping on the carbonate geochemistry of the groundwaters. Also, the stable isotope data from the basin were compared with similar data from other parts of the country to show the continental effect.
6 citations
TL;DR: In this paper, the authors studied the relationship between the groundwater in the Quaternary sediments and in the underlying Middle Turonian confined aquifer in the Czech Republic, by means of stable isotopes and radionuclides.
Abstract: During hydraulic dumping of ashes at a sludge bed of the power plant at Mělnik (north of Prague), new springs originated which wetted houses and properties at the small village of Podvlci. The sludge bed as well as the village lie at the southwestern margin of the alluvial plain of the Labe (Elbe) River at the foot of a slope built of Cretaceous sedimentary rocks. By analyzing the concentrations of radiocarbon and tritium, it was possible to determine the origin of the water and the ratio of the modern and original groundwater in the new springs in the surroundings of the sludge bed. To substitute the present dump the operation of which should be stopped, establishing of a new one has been proposed within the alluvial plain. By means of stable isotopes and radionuclides, the relations between the groundwater in the Quaternary sediments and in the underlying Middle Turonian confined aquifer were studied, because changes in the hydrogeological regime have to be expected due to the operation of the ...
3 citations
01 Jan 1993
TL;DR: In this paper, a research program was undertaken to investigate into the hydrogeological conditions of the coal mine, employing environmental isotopes techniques, and the No. 7 mine is located at the area of south-west corner.
Abstract: Pingdingshan Coal Mining Area lies in the western part of Henan Province, and the No. 7 mine is located at the area of south-west corner. With the increase of the mining depth, the threat of karstwater from aquifer underlying the coal seam become progressively alarming to the mine workings. A research program was undertaken to investigate into the hydrogeological conditions of the coal mine, employing environmental isotopes techniques.
TL;DR: The isotopic composition of thermal and mineral waters of Mongolia is discussed in this article, where a certain similarity between the waters of Mongolian waters and those of East Siberia can be derived from the obtained data.
Abstract: The isotopic composition (D, 18O, 87Sr, 3He) of thermal and mineral waters of Mongolia is discussed. The Sr-isotope ratio depends on the rock's contact. Near the Chubsugul-lake 3He-/4He-values are high. A certain similarity between the waters of Mongolia and those of East Siberia can be derived from the obtained data.