Thermobarometric and Petrological Study of Mafic Xenolithes in Plagiogranites of the River Lotta Area of the Central Zone of the Lapland Granulite Belt

Authors: Butvina VG and Safonov OG

DOI: 10.23880/ppej-16000150

Volume 2, Issue 3

Abstract

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

Keywords: Lapland Granulite Belt; The River Lotta Area; Granulite; Amphibolization; Thermobarometric data

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