V–Cr–Nb–W-Bearing Rutile in Metamorphic Rocks of the Slyudyanka Complex, Southern Baikal Region

The paper presents data on accessory rutile in Cr–V-rich metamorphic rocks of the Slyudyanka crystalline (granulite) complex in the southern Baikal region. The geochemical features of the studied rutile are unique in combining isomorphic admixtures typical of the mineral from either mafic (Cr) or felsic igneous and associated metasomatic rocks (W), as well as the Nb and V contents, which are abnormally high for metamorphic rocks. The highest concentrations of these elements are as follows, wt %: 15.38 V2O3, 4.33 Cr2O3, 11.09 Nb2O5, 12.36 WO3. These high W and V contents have never been measured in natural rutile. The studied rutile is compared to that from other Cr–V-bearing rocks in the world and various genetic types. The optimal isomorphic substitutions and probable conditions of their realization are discussed.