The carbonaceous matter in ore-placer systems with noble metal mineralization

Abstract

The article presents the results of original studies of the elemental composition of carbonaceous matter (CM), the morphology of its secretions and the relationship with precious metal minerals. It has been established that the elemental composition of hydrocarbons in different ore-placer objects varies from simple, two-three-element in endogenous deposits and ore occurrences, to multielement in weathering crusts, technogenic placers and ore ferromanganese crusts, which may be a typomorphic feature in the reconstruction of the genesis of a particular mineral system. CM emissions mainly relate to bituminous carbonaceous matter. Different types of carbonaceous matter with specific morphology, different elemental composition andatomic-crystalline affinity for noble metals were encountered. The main morphological forms of CM secretions in the matrix are xenomorphic and isometric, veined, lamellar, film, wire-shaped, shell-shaped, spherical, nanodispersed (cluster) and other forms are also present. Spatial relationships of CM emissions with noble metals and associated rocks and minerals have been established. They are as follows: CM emissions are mainly concentrated in interstices and cavities of the mineral matrix, in intergranular spaces, in intracrystalline voids of ore quartz, and can also be contained in the crystal structure of the noble metal and in a dispersed nanodis-persed state in rocks that are in coalescence with gold. It is not uncommon for CM to occur in the form of separations or primers on the surface of gold pieces.