ABSTRACT
Abstract — Fine structure of the dissolved and suspended components in the zone of interaction of aerobic and anaerobic waters in the Black Sea is considered. Continuous in situ measurements and iodometric determinations of oxygen concentration in the course of sample taking and fixing in the inert gas atmosphere have been conducted. The former oxygen measurements with concentrations less than 1 mi l " by the traditional techniques are shown to be incorrect owing to the penetration of atmospheric oxygen. The thickness of the coexistence layer does not exceed several meters and the oxygen concentration there is 0.05 ml 1 at most. Some regularities in oxygen and hydrogen sulphide distributions in the area of their interaction are demonstrated. The layers containing extreme concentrations of suspensions and suspended carbon, nitrogen, iron, manganese, sulphur, phosphorus, and microelements are localized. The relationship between chemical and physical isopycnic surfaces in the O2/H2S interaction area is defined. The depth of the boundary of H2S waters does not always strictly correspond to the 0.013 m _ density gradient. The major contribution to the formation of a turbid layer over the anaerobic waters boundary is from colloidal manganese hydroxide.
