The correlations between the well-defined components of the compositions of the hydrothermal solutions (their end members) was examined. A principal group of elements is distinguished that have persistent positive correlations, both quantitatively and qualitatively: Cl-Na-Ca-Mn-Fe-Zn. The elements in the set determine the compositions and geochemical features of the hydrothermal solutions as regards the macroscopic and microscopic compositions, while the triad of trace components (Mn, Fe, and Zn) is the leading feature in the geochemical pattern of the hydrothermal plumes. It is thought that the main role is played by dissolved forms of Mn and suspended forms of Fe while the black smoke from the smokers consists mainly of Fe sulfides and hydroxides. -from Journal translation