Gabbroids and Monzonitoids of the Tigriny Ore Cluster (Sikhote-Alin): Composition, Age, Geodynamic Setting, and Relationship with Mineralization

This article presents the results of the study of the mineralogical and petrographic characteristics, composition, and age of gabbroids and monzonitoids of the Burelomny Creek massif, which is located in the Central Sikhote-Alin and is spatially associated with the Tigriny rare-metal–granite intrusion and eponymous Sn–W deposit. It is shown that the gabbroids and monzonitoids of the massif correspond to the high-potassium rocks of the normal and moderately alkaline series and have low concentrations of titanium, high concentrations of phosphorus, and moderate concentrations of HFSE and REE elements. The geochemical characteristics of the rocks indicate that they were derived from mixed lithospheric and sublithospheric mantle protoliths in a setting of a transform continental margin. The age of the gabbroids determined by the Ar–Ar dating of the biotite monofraction is 101 ± 1.5 Ma, which coincides with the “peak” of basite and granitoid magmatism in Sikhote-Alin. The significant difference in age (more than 20 Ma) and geochemical specialization indicates that the Tigriny rare-metal granite massif and associated mineralization have no genetic relationship with the gabbroids and monzonitoids of the Burelomny Creek massif.