The Early Cretaceous Collisional Granite-Leucogranite Association of the Stanovoi Terrane: New Geochronological, Geochemical, and Isotope-Geochemical Data

摘要

The granite-leucogranite plutons traditionally recognized as the Irakan Complex are widespread in the Stanovoi Terrane. This plutonic association comprises (Ⅰ) biotite-hornblende quartz monzodiorite, (Ⅱ) biotite-hornblende granite, and (Ⅲ) biotite-bearing leucogranite and subalkali leucogranite intrusive phases. According to the K-Ar datings, phase Ⅱ is composed of Early Cretaceous granites, while phase Ⅲ includes Late Cretaceous leucogranites. Gold placers and gold-tungsten and molybdenum ore occurrences are spatially associated with granite-leucogranite plutons. The geochronological, geochemical, and isotope-geochemical studies of the Tokko-Sivakan pluton, which is typical of the granite-leucogranite association, allowed us to substantiate its Early Cretaceous age, characterize the rock compositions in more detail, and decipher the composition and age of the initial substrate (source material). These data are of great importance for the substantiation of the Early Cretaceous stage of granitoid magmatism in the Upper Amur region at 110 ± 3 Ma.