Regularities of uranium, ionium, radium and thorium distribution in the basin of the Black Sea and the Asov Sea

Analyzed is the distribution of U,Ra, and Th isotopes in waters and sediments of the Black Sea and the Asov Sea and also in waters and suspended material of lagoons and rivers, incoming into these basins. U content in the upper part of the Black Sea sediments reaches (10-12)x10-6 g/g, that is 5-7 times higher than in typical ocean sediments, and in the lower part it coincides with the latter (1-3)x10-6 g/g. The 234U/238U relation in the waters of the Black Sea does not exceed 1.26+-0.19 and in the waters of the Asov Sea 1.28+-O.06. Enrichment of waters with 234U occurs due to water interaction with containing rocks. Th-232 content in the Black Sea waters varies within the limits (1.4-3.9)x10-9, and in the Asov Sea waters from 4x10-9 g/l to 2.19x10-9 g/l, and are proportional to the rate of water contamination with terigene suspension Ra content in the Black Sea waters is on the average (1+-0.1)x10-13 g Ra/l in the Asov Sea waters - 1.4x10-13 g Ra/l. Mesothorium - 1 concentration in sea waters is by 3 orders higher than that of 232Th, which points to separate geochemical history of the element, independent of the presence of 232Th in water. This notion can be used for time determination of isotope presence in water. ''Water age'', water exchange rate etc