Petrogenesis of charnockites in the Turku granulite area

: Helenius Eeva-Maria, Eklund Olav, Väisänen Markku, Hölttä Pentti

: Carl Ehlers, Olav Eklund, Annakaisa Korja, Annika Kruuna, Raimo Lahtinen, Lauri J. Pesonen

: Third Symposium on the Structure and Evolution of the Lithosphere in Finland

: Institute of Seismology, University of Helsinki

: 2004

: Lithosphere 2004

: Report-S

: 45

: 17

: 20

: 4

: 951-45-7999-2

: 0357-3060

: http://www.seismo.helsinki.fi/pdf/LITO2004.pdf

Charnockites are either plutonic or metamorphic orthopyroxene-bearing quartzofeldspathic rocks. This study shows that the charnockitic rocks within the Turku granulite area were formed under granulite facies conditions from tonalitic granitoids through charnockitization reactions. Biotite and amphibole reacted with quartz to form pyroxene, plagioclase ± potassium feldspar.