Noble metals in silicate-magnetite ores of the Triassic chert formation of the Sikhote-Alin.

Abstract

A feature of the noble-metal mineralogy in the stratified silicate-magnetite ores of the Triassic chert formation of the Sikhote-Alin is the occurrence of native gold without admixtures, gold-silver solid solution, “cupriferous gold”, native platinum without admixtures, palladium platinum, copper platinum, sperrylite, native silver, pyrargyrite, and silver sulfide. The noble-metal mineralization was formed in the process of the contact metamorphism of the lithified Triassic metal-bearing sediments at the expense of the protolith matter as well as at the expense of noble metals of the Triassic carbonaceous silicites that migrated along the fractures into other rocks in the fluid composition with the high- and ultra-reducible abilities.