ИСТИНА

Garnet and orthopyroxene plagiogranites within the Lapland Granulite Belt (LGB) are confined to the northeastern part of the complex, building large areas in the Lotta river and Lovnaozero lake regions and extending westward to northern Norway (Mitrofanov et al., 1974; Kozlov and Kozlova, 1998). They are usually associated with peraluminous granulites (khondalites), showing intrusive contacts with these country rocks. Based on chemical and mineral composition of plagiogranites, which are typical for the S-type granites, the plagiogranites are usually considered as products of anataxis of khondalites at the peak of D3/M3 metamorphism during ~1.91 Ga at temperatures 800-850°C within a wide pressure interval 6.8-9.5 kbar (Mitrofanov et al., 1974; Kozlov, Kozlova, 1998; Mints et al., 2007, 2015; Kaulina et al., 2014). Magmatic origin of the plagiogranites is confirmed by a presence of xenoliths of various lithologies, which are products of earlier metamorphic stages at 1.97-1.96 Ga (e.g. Kaulina et al., 2014). Among the xenolith rocks, mafic rocks are abundant, but are not investigated in detail. Therefore, the object of this study are mafic (amphibolized two pyroxene-plagioclase-quartz rocks) xenoliths in plagiogranites of the river Lotta Area of the Central Zone of the LGB. These xenoliths reflect interaction of mafic rocks with fluids issued by granitic magmas during their crystallization.