A New Genetic Type of Gold Deposits-Meso-Epithermal Carbonate-Type Gold Deposits as Exemplified by the Baguamiao Superlarge Gold Deposit

<正>Gold deposits of the meso-epithermal carbonate type were first proposed based on the study of the Baguamiao gold deposit. This new type of gold deposits has many unique characteristics as follows: (1) Obviously strata-bound. The gold deposits are hosted in Middle Devonian turbidite formations; (2) Structurally controlled. Structure is an important factor leading to metallogenesis of this type of gold deposits. The shape and distribution of orebodies are controlled by brittle-ductile shear zones; (3) Multistage wall-rock alteration. According to the characteristics of mineral assemblage, gold mineralization can be classified into three stages in association with various wall-rock alterations. Wall-rock alterations closely genetically related to the gold mineralization are ankerization, silicification, pyrrhotization and pyritization; (4) Mineral compositions of the orebodies are mainly pyrrhotite, pyrite, marcasitolite, chalcopyrite, quartz, ankerite, and sericite. Gold mineralization is associated closel