The in-situ trace elements of gold-bearing pyrites from Suoluogou gold deposit, Muli, Sichuan

The Soluogouis a large-scale gold deposit in Garze-Litang Suture, but its genesis is still controversial. In order to probe into the genesis of the Soluogou deposit, LA-ICP-MS in-situ trace element analyses of anhedral and euhedral pyritohedron gold-bearing pyrites from the Soluogou gold deposit have been carried out. The results show that the variation range of elements’ contents of anhedral pyrite in Soluogou is narrow, while euhedral pyrite has obvious core-mantle-edge structure and its variation range of elements’ contents is large. On the whole, Au in pyrite is positively correlated with As and negatively correlated with FeS₂ and Co/Ni values, existing in the form of lattice gold. The Co/Ni values of anhedral and euhedral pyrite are 0.2 and 57.1, respectively. Both anhedral and euhedral pyrites have a high Au content and a low Ag content. It is concluded that anhedral pyrite is derived from sedimentation while euhedral pyrite is formed in hydrothermal process. The Soluogou gold deposit is a typical orogenic gold deposit, which is characterized by the reactivation and enrichment of Au in volcanic-sedimentary rocks under the action of metamorphic hydrothermal.