ON THE PECULARITIES OF ORTHO-PYROXENE CHE MICAL EVOLUTION OF NICKEL BEARING BASITE-HYPERBASITE SERIES OF THE KOLA-PENINSULA

The pecularities of isomorphism and chemical evolution of the orthopyr oxenes of nickel bearing basite-hyperbasite series of the Kola peninsu la were studied. It was shown that the predominant isomorphic substitu tion of Mg and ferrous iron ale characteristic of all orthopyroxenes o f nickel bearing series and is interpreted as a function of lock compo sitional variations. Every nickel bearing series are also characterise d with peculiar isomorphic types depending on different conditions of mineral formation and secondary alteration processes.