Proterozoic Granitoid Magmatism at the Southwestern Margin of the Siberian Platform in the Tectonic History of the Angara–Kan Block

The large massifs of ancient granitoids of the South Yenisei Ridge are divided into three complexes that differ in the geological, geochemical, and geochronological features. The Tarak massif consists of two complexes of different ages: the S–A-type porphyritic granitoids (collisional) of the Tarak complex (1.84 Ga) and the A-type subalkaline granites (anorogenic) of the Telkun complex (1.76 Ga). The magmatic crystallization of gneiss granites of the Posolnenskii complex is interrelated with the late stage of metamorphism and falls into the age interval between the above two complexes (1789.8 ± 8.9 Ma). Metamorphic transformations of the enclosing formations are recorded by the presence of small bodies of charnockitoids with dates of 1.84 and 1.73 Ga.