Relying on the analysis of vertical distribution of phosphate and silicate as well as of vertical concentration gradients of these hydrochemical parameters above the mud volcano on the northwest Black Sea shelf the author came to a conclusion that mud volcanoes can be an endogenous source of silicate.

The phenomena of saltish water paradox in amphibian geoecosystems of foreland, with a specific type of ecosystems characterized by low biodiversity and high biological productivity is considered.