Geochemistry of sapropel in the Black Sea

Abstract

531 Sapropels, which were first found in the Black Sea and described there by Andrusov [1] and were later examined by several researchers [2–13], are interest ing as analogues of ancient metalliferous black shale sequences that were formed in hydrogen sulfide con taminated basins. This issue was actively discussed in the literature [2–5], but no definite geochemical comparison was made so far on the basis of original and/or literature data. The factual material for this research was collected by the author in the western part of the Black Sea in the course of cruises of the R/V Mikhail Lomonosov (Hydrophysical Institute of the Ukrainian Academy of Sciences) and R/V Vityaz (Shirshov Institute of Oceanology, Russian Academy of Sciences) in 1966 and 1984. The sampling sites are specified and descriptions of sediment samples are given in Table 1. The major component composition of the samples was studied at the Shirshov Institute of Oceanology, Russian Academy of Sciences, by atomic absorption and conventional chemical techniques (analysts N.N. Zavadskaya and N.P. Tolmacheva). trace ele ments were analyzed by ICP MS at the Analytical Certification and testing Center at the Fedorovskii All Russia Institute of Mineral Resources under the supervision of S.V. Kordyukov. The bottom sediments of the Black Sea consist of three lithologic–stratigraphic complexes, which were dated by radiocarbon methods [14–17]: Upper Late Black Sea (modern to 3000 yrs), Middle or Early Black Sea (3000–7000 yrs), and Lower or Late Euxin ian (older than 7000 yrs).