Mineralogical-Geochemical Peculiarities of Ores in Pyritaceous Fields ofFilizchai Type in the Greater Caucasus

Abstract

• Pyritaceous fields of the south slope of the Greater Caucasus confined to the Lower-Middle Jurassic sandy
  clayey deposits are: polygenic polychrone formations which were formed by a complex of hydrothermal sedimentary.
  hydrothermal metasomatic and hydrothermal metamorphogenic processes of ore formation. Filizchai pyritaceous
  polymetallic field is the largest in the region and can be characterized by diversity of texture-mineralogical types of
  ores, rich mineral composition and with geochemical spectrum. Some of the admixture components (Cd, In, TI, Ga,
  Ge.Se, Hg) are only in isomorphic forms in ores, others (Te, Bi, Au, Ag, Co, Sn, As) along with it characterize in their
  own minerals. The Co is mainly concentrated in pyrite, pyrrhotine; Ag, Bi and also Te -in galenite and chalcopyrite;
  Se- in pyrite. pyrrhotine and galenite; in sphalerite (mainly in marmatite) and chalcopyrite; Cd. Ga, CGe- in sphalerite.
  mainly in cleiophane; Au -in pyrite and chalcopyrite; TI -in galenite and colloform pyrite. In all sulphides selenium
  prevails over tellurium (excepting the late chalcopyrite) and cobalt over nickel, Maximum amount of cobalt is confined
  to pyrite from pyritaceous polymetallic ores and late generation of pyrrhotine, The nature of the connection between
  chemical elements in ores coordinates with determined stages of minerals formation. The main productive stage of
  ore formation bringing the main mass of gold, silver, rare and other precious components of ores are sulphosalt
  polymetallic stage of sulphur ploymetallic stage. Comparative analysis of absolute content of gold, silver and values
  of gold-silver relation in pyrite fields ores of region with appropriate values in meteorite standard indirecty indicates
  the relationship between gold-silver mineralization and assimilation crust source.