Sulfur speciation in bottom sediments from deep-sea basins of the Atlantic Ocean

Distribution of reduced sulfur forms in vertical sediment sections in deep-sea basins of the Atlantic Ocean is under study. Presence of weak sulfate reduction process resulted from low concentrations of reactive organic matter and differing by characteristic features of the initial stage of development. Interpretation of results is given on the base of consideration of dynamic redox equilibrium in the system: reduced sulfur - dissolved oxygen.

Distribution of species of planktic foraminifera in bottom sediments of the Morocco Basin

Two lithological-stratigraphic intervals have been distinguished in the Morocco basin by a study of lithologic composition of bottom sediments as well as of planktic and bottom foraminifera present in them. Conditions, under which they developed, are discussed.

Hydrocarbons in surface waters of the Atlantic and Indian Oceans

Results of investigation of various forms of oil pollution, i.e. oil films, tar, and hydrocarbons in the Northeast Atlantic Ocean and North Indian Ocean during October-December 1980 and February-May 1981 are presented. Oil pollution was found only in regions of the heaviest ship traffic and was somewhat less than in 1976-1977. Background concentration of non-polar hydrocarbons was 8-10 ?g/l in surface waters and 14 ?g/l in the shelf zone. Infrared spectroscopy and gas-liquid chromatography indicate that hydrocarbons occurring at concentrations exceeding 50 ?g/l have composition differing from background hydrocarbons. There is considerable accumulation of hydrocarbons in the thin surface layer, and they exist in different forms close to pollution sources.