Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Geochronometria

2 2004

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Radiocarbon in elements of the landscape (Belarus)

Mikhajlov N., Kolkovskij V., Pavlova I., Luchina G.

Geochronometria

2004

Vol. 23

59-66

It was found that in areas distant from an operating NPP the 14C concentration is characterized by values of 105-108 pMC. In the area of the Ignalina plant rather high 14C contents of vegetation (up to 150 pMC), and water of the lake Drisvyaty (127-154 pMC) connected by canals with the Ignalina NPP were noted. Biocarbonates (shells of lake mollusks Anadonta cygnaea and Dreissena, eggs poultry fed) are also enriched in radiocarbon. The concentrations of 14C in plants sampled in 1994-1996 in Gomel region (Chernobyl zone) are similar to those from the Ignalina NPP region and show increased values (up to 130-140 pMC). On the other hand, an emission of the radiocarbon resulted from the Chernobyl accident was recorded in the biosphere, at its concentrations increased toward the plant. So, 14C values were about 200 pMC near Minsk (May-June, 1986) and reached 600-700 pMC near Gomel. These data permit a realistic estimate of the concentrations of the radiocarbon emission at the instant of the accident. The radioisotope is well preserved and its redistribution occurs mainly due to biochemical processes. This is well shown by the radiocarbon distributions in a profile of the soil boggy medium.

Carbon isotopic composition of fresh groundwater in the territory of Belarus (in the context of its vulnerability estimation)

Mikhajlov N., Kolkovskij V., Pavlova I., Luchina G., Kolosov I.

Geochronometria

2004

Vol. 23

67-70

Investigations of the distribution of the carbon isotopes (14C, 13C) at water intakes used for drinking water supply of Minsk (Quaternary and Upper Proterozoic aquifers complexes) and Gomel (Cretaceous and Paleogene aquifers) became the first stage of works aimed at the estimation of vulnerability of fresh groundwater aquifers in Belarus. The radiocarbon concentrations obtained and corrections for carbon stable isotopes were used to calculate the formal and corrected radiocarbon age (time of occurrence in an aquifer) of fresh groundwater of the studied aquifers. So, the most ancient radiocarbon age is characteristic of water samples from the Upper Proterozoic aquifer of Belarusian hydrogeological massif in the Minsk region (12,000-14,000 years). Fresh groundwater from the Cretaceous aquifer in the junction zone of the Pripyat artesian basin and Voronezh hydrogeological massif (Gomel region) show wider age range (7000-15,000 years). As aquifers of Belarus become younger, the groundwater isotope composition area comes more similar to the recent water area (II). An analysis of isotope ratios suggests (area I) that only a part of groundwater samples from Cenozoic aquifers (Paleogene and Quaternary Dnieper-Sozh horizon is found in the area of radioactive decay (this is more typical for water from Paleogene aquifer) and may corresponds to the actual time of its occurrence in an aquifer.