P-T and fluid conditions of interaction between mafic xenolithes and plagiogranites in the Lotta River Area, Lapland Granulite Belt
Thermobarometric data and fluid inclusions data of conditions of interaction between mafic xenolithes (granulites) and plagiogranites in the Lotta river area, Lapland Granulite Belt, confirm the conclusion that leucocratic garnet-bearing plagiogranites of the Lapland complex are associated with the anatexis of country khondalites during the peak of metamorphism. The formation of these magmas occurred at depths of 25-30 km. During their ascent, granitic magmas trapped mafic (two pyroxene-plagioclase) xenoliths at pressures of 6.0-6.4 kbar. The interaction of predominantly aqueous-salt fluids produced by magmas with xenoliths during cooling at depths of less than 20 km (5.0-5.5 kbar) led to their widespread amphibolization at temperatures of 740-780°C.